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Introduction to chemical engineering : for chemical engineers and students
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Introduction to Chemical Engineering

Scrivener Publishing 100 Cummings Center, Suite 541J Beverly, MA Publishers at Scrivener Martin Scrivener ([email protected]) Phillip Carmical ([email protected])

Introduction to Chemical Engineering For Chemical Engineers and Students

Uche Nnaji

This edition first published 2019 by John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, USA and Scrivener Publishing LLC, 100 Cummings Center, Suite 541J, Beverly, MA 01915, USA © 2019 Scrivener Publishing LLC For more information about Scrivener publications please visit www.scrivenerpublishing.com. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, except as permitted by law. Advice on how to obtain permission to reuse material from this title is available at http://www.wiley.com/go/permissions. Wiley Global Headquarters 111 River Street, Hoboken, NJ 07030, USA For details of our global editorial offices, customer services, and more information about Wiley products visit us at www.wiley.com. Limit of Liability/Disclaimer of Warranty While the publisher and authors have used their best efforts in preparing this work, they make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives, written sales materials, or promotional statements for this work. The fact that an organization, website, or product is referred to in this work as a citation and/or potential source of further information does not mean that the publisher and authors endorse the information or services the organization, website, or product may provide or recommendations it may make. This work is sold with the understanding that the publisher is not engaged in rendering professional services. The advice and strategies contained herein may not be suitable for your situation. You should consult with a specialist where appropriate. Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages. Further, readers should be aware that websites listed in this work may have changed or disappeared between when this work was written and when it is read. Library of Congress Cataloging-in-Publication Data ISBN 978-1-119-59210-5 Cover image: Oil Refinery, Tebnad | Dreamstime.com, Abstract Chem Background: Bestbrk | Dreamstime.com Cover design by Kris Hackerott Set in size of 11pt and Minion Pro by Manila Typesetting Company, Makati, Philippines Printed in the USA 10 9 8 7 6 5 4 3 2 1

Contents Preface Foreword Acknowledgements 1

Introduction 1.1 Definition of Chemical Engineering 1.1.2 Chemical Engineers 1.2 It is the Broadest Branch of Engineering 1.3 Chemical Engineering – a General Purpose Technology 1.4 Relationship Between Chemical Engineering and the Science of Chemistry 1.4.1 Chemical Engineers Take Chemistry Out of the Laboratory and Into the World 1.5 Historical Development of Chemical Engineering 1.5.1 Industrial Chemistry and Mechanical Engineering 1.5.2 Unit Operations 1.5.3 Chemical Engineering Science 1.5.4 Chemical Systems Engineering 1.6 Anatomy of a Chemical Engineering Plant 1.6.1 Overview 1.6.2 Process Units 1.6.3 Process Interconnecting Piping (Pumps, Piping & Valves) 1.6.4 Power/Electrical Unit 1.6.5 Process Laboratory 1.6.6 Process Control 1.6.7 Storage Tanks 1.6.8 Flare and Atmospheric Ventilation Unit 1.6.9 Workshop and Lay-down Area 1.6.10 Office Building and Others

xiii xv xvii 1 1 3 6 7 7 10 12 13 19 22 23 23 23 25 27 27 28 29 31 32 34 34 v

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Contents 1.6.11 1.6.12 1.6.13 1.6.14

Warehouse and Storage Firefighting Unit Water Generation Unit Waste Treatment and Disposal Unit

35 35 36 36

2 Chemical Engineering Basic Education and Training 2.1 Introduction 2.2 Chemical Engineering Education Model 2.3 Objectives of Chemical Engineering Education 2.4 Academic Shift from Science to Engineering 2.5 Chemical Engineering Core Subjects and Applications 2.5.1 Chemical Reaction Engineering 2.5.1.1 Applications of Reaction Engineering 2.5.1.2 The Chemical Reactor 2.5.2 Thermodynamics for Chemical Engineers 2.5.2.1 Applications of Thermodynamics 2.5.3 Transport Phenomena (Transport Processes) 2.5.3.1 Applications of Transport Phenomenon 2.5.4 Separation Processes 2.5.4.1 Applications of Separation Processes 2.5.5 Process Dynamics and Control 2.5.5.1 Applications of Process Dynamics and Control 2.6 General Skills in Chemical Engineering Education 2.7 New Chemical Engineering Hire 2.7.1 Transitioning from the University to Professional Engineering Career 2.7.2 Job Assignment of a Trainee Chemical Engineer 2.7.3 Required On-the-Job Training and Skills 2.7.4 Expected Challenges for the New Chemical Engineer 2.7.5 Career Growth Path and Success Factors 2.8 Registration of Engineers 2.8.1 Institution of Chemical Engineers (IChemE) 2.8.1.1 IChemE Membership Grades 2.8.2 American Institution of Chemical Engineers (AIChE) 2.8.2.2 AIChE Membership Grades

37 37 37 39 40 44 44 45 46 49 50 52 53 55 57 60

3

79 79 81 82

Chemical Engineers’ Areas of Expertise 3.1 Introduction 3.2 Energy and Sustainability Segment 3.2.1 Petroleum Refining

62 63 63 64 65 66 68 70 71 72 74 76 77

3.3 3.4

3.5 3.6

3.7 3.8 3.9

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3.2.2 Synthetic Liquid Fuels 3.2.2.1 Fuels from Biomaterials 3.2.2.2 Electricity Generation from Coal 3.2.3 Hydrogen Fuel 3.2.4 Solar and Wind Energy 3.2.5 Nuclear Energy Food Segment Biomedicine (BME)/Biotechnology/Bioengineering Segment 3.4.1 Biomedical or Tissue Engineering 3.4.2 Biotechnology-Based Chemicals 3.4.3 Pharmaceutical Engineering 3.4.4 Kidney Dialysis, Diabetes Treatment, and Drug Delivery Systems Electronics Segment Materials Segment 3.6.1 Biomaterials 3.6.2 Plastics Materials 3.6.3 Telecommunications Materials 3.6.4 Computer Chips Materials 3.6.5 New Researches Space Program The Environment Segment 3.8.1 Green Engineering Summary of Industry Segments Served by Chemical Engineers

84 84 86 87 88 89 90 95 95 96 97

4 Career Diversities in Chemical Engineering 4.1 Introduction 4.2 Career Development Leading to Specialization 4.3 Chemical Engineering Job Titles/Options 4.3.1 Biochemical Engineer 4.3.2 Chemical and Process Engineers (Design Engineers) 4.3.3 Refinery Engineer 4.3.4 Chemical Development Engineer 4.3.5 Commissioning Engineer 4.3.6 Maintenance Engineer/Maintenance Planning Engineer/Process Maintenance Engineer 4.3.7 Process Control/Automation Engineer 4.3.8 Process Safety Engineer 4.3.9 Biomedical Engineer 4.3.10 Research & Development Engineer

98 99 101 103 103 104 105 105 106 108 110 111 115 115 115 118 118 119 123 124 126 127 129 131 134 136

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Contents 4.3.11 Sales Engineer 4.3.12 Performance Control Engineer 4.3.13 Planning Engineer 4.3.14 Facilities Process/Plant Engineer 4.3.15 Pharmaceutical Engineer/Pharmaceutical Process Engineer 4.3.16 Site Engineer 4.3.17 Production Engineer 4.3.18 Pipeline Engineer 4.3.19 Petroleum (Production, Reservoir and Drilling) Engineer 4.3.20 Environment Engineer 4.3.21 Materials Engineer 4.3.22 Piping and Lay-out Engineer 4.3.23 Project Engineer 4.3.24 Cost Control/Cost Engineer 4.3.25 Contracts Engineer 4.3.26 Chemical Manufacturing Engineer 4.3.27 Quality Process Engineer/Quality Control Engineer 4.3.28 Others 4.4 Chemical Engineering Professional Critical Success Factors

5 Design and Chemical Engineering Practice 5.1 Introduction 5.2 Chemical Process and Plant Development Steps 5.2.1 General 5.2.2 Process and Technology Development 5.2.3 Engineering Design 5.2.3.1 General 5.2.3.2 Conceptual/Basic Engineering Design/ Feasibility Study 5.2.3.3 Front-End Engineering Design (FEED) 5.2.3.4 Description of the Key Process Engineering Deliverables/Activities 5.2.3.5 Process Narrative/Description 5.2.3.6 PFD Review 5.2.3.7 Chemical Engineering Equipment Descriptions for PFD and P&IDs 5.2.3.8 Detailed Process and Engineering Design 5.3 Construction, Pre-Commissioning, Commissioning & Startup

138 139 140 141 142 144 146 147 149 151 152 153 155 156 158 159 160 162 163 165 165 166 166 168 177 177 178 185 187 197 198 204 208 217

Contents 5.4 Case Study of Chemical Engineering Equipment Design – Horizontal KOD Liquid-Vapor Separator 5.4.1 Introduction 5.4.2 Knock-Out Drum Separator Design 5.4.2.1 Scientific Principles Applied 5.4.2.2 Design Parameters 5.4.2.3 Design Data and Solution 5.4.2.4 Conclusion 5.5 Economic Study of a Chemical Engineering Process 5.6 Case History Related to the Development of a New Chemical Process 5.6.1 Conceptual and Front-End Engineering Design 5.6.2 Detailed Engineering Design and Construction 5.6.3 Pre-Commissioning and Commissioning 5.6.4 Plant Operation

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218 218 221 221 225 228 241 241 247 247 248 251 252

6 Chemical Process Safety Engineering and Management 6.1 Introduction 6.2 Chemical Engineering Design for Process Safety 6.2.1 Selection of Inherently Safer Process Route 6.2.2 Process Design 6.2.3 Incorporating Process Safety into Process Equipment Design 6.2.4 Preventive and Protective Design Features 6.2.5 Safety Administrative or Procedural Control (Active Solutions) 6.3 Process Hazard Analysis Techniques 6.3.1 Hazard and Operability Study (HAZOP) 6.3.2 Process Safety Design Verification 6.4 Process Safety Management

253 253 255 255 256

7 Sustainability in Chemical Engineering Design 7.1 Introduction 7.2 Sustainability Model 7.2.1 Sustainable Raw Materials 7.2.2 Sustainable Manufacturing Process 7.2.3 Sustainable Consumption/Behavior 7.3 Sustainability in Chemical Engineering 7.4 Chemical Engineering Sustainability Design and Research Problems 7.4.1 Key Challenges 7.4.2 Technologies for Sustainability

277 277 279 282 283 285 286

259 261 264 264 265 273 274

290 292 292

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8 Chemical Engineering Computer Software Tools and Applications 8.1 Introduction 8.2 Development of Chemical Engineering Computer Software 8.3 Process Engineering Design Software (HYSYS and PRO II) 8.3.1 HYSYS Process Engineering Design Software 8.3.2 PRO II Process Engineering Design Software 8.4 Statistical and Numerical Analysis Software 8.4.1 Engineering Computations Using Microsoft Excel 8.5 Computer Programming and Control Software (MATLAB and Visual Basic) 8.6 Computer-Aided Design & Drafting (Auto-CAD) 8.7 Piping and Equipment Design Software 8.8 Others 8.8.1 Presentation Software (Power Point) 9

Graduate Programs in Chemical Engineering 9.1 Introduction 9.1.1 Master’s Degrees 9.1.2 Doctoral-Level Degrees 9.2 Requirements for Graduate Program in Chemical Engineering 9.3 Options in Chemical Engineering Postgraduate Programs 9.3.1 Advanced Chemical Engineering with Biotechnology/ Biochemical/Medical/(Bio) Engineering 9.3.2 Engineering Management in Chemical Engineering 9.3.3 Advanced Materials Engineering Option 9.3.4 Process Systems Engineering (PSE) Option 9.3.5 Chemical Process Engineering 9.3.6 Oil and Gas Engineering 9.3.7 Advanced Chemical Engineering with Polymer Engineering 9.3.8 Advanced Chemical Engineering with Structured Product Engineering (SPE) 9.3.9 Process Automation, Instrumentation and Control Option 9.3.10 Process and Equipment Design Option 9.3.11 Advanced Chemical Engineering with Information Technology and Management

295 295 295 297 297 298 301 301 303 309 311 313 313 315 315 316 317 318 319 320 321 322 323 325 325 326 327 328 329 329

Contents 9.3.12 Innovative and Sustainable Chemical Engineering 9.3.13 Catalysis, Kinetics & Reaction Engineering 9.4 Chemical Engineering Research Needs and Opportunities

xi 330 330 330

References

337

Index

345

Preface This book offers a comprehensive overview of the evolution, essence, concept, principles, functions and applications of chemical engineering. It systematically describes the link between the foundational science of chemistry, biology and processes, to the engineering that delivers the required hardware functionality and products. It further explains the distinct chemical engineering knowledge, which, although it originally stems from the synthesis of mechanical engineering and industrial chemistry, has given rise to a general-purpose technology and the broadest engineering field. The discipline is wide-ranging in scope and flexibility; it focuses at the molecular level—in terms of chemical, biological, and physical transformations that occur at this level, while at the same time focusing at the process and systems level—in terms of the process design and systems engineering that deliver the required product. Hence, the text in clear terms traces these broad facets of the field, the various industry segments served and the discipline’s contribution to global industrialization and well-being of humankind. Today, chemical engineering has evolved to such a unique knowledge area, which establishes the fact that the combination of a mechanical engineer and a chemist is not an alternative to a chemical engineer in an industrial setting. The various features of a typical chemical engineering plant are described in this text. Moreover, it explains the education and training of chemical engineers and how the subjects studied in the class are integrated into the real-world of work. It likewise discusses career diversities in modern chemical engineering; and attempt is made to rate the level of chemical engineering knowledge being applied in the respective career options. It further details the real activity model of the core chemical engineering knowledge base—process plant and equipment design, with a practical equipment design case study. Also, it shares the origin of chemical engineering information technology (the computer tools) and their applications. The book presents options in chemical engineering graduate programs, the requirements and how the options can provide graduates with xiii

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advanced chemical engineering, process technology, production and managerial skills for exciting and challenging careers. The current focus of the discipline is sustainable systems development through the integration of process safety, process systems engineering, process intensification, product design, life cycle analysis, cutting edge innovations in catalysis, materials, nanotechnology, molecular biology and advanced process economy. Thus, this book presents the global sustainability model and the unique role the frontiers of chemical engineering play toward ensuring sustainable solutions. This book is expected to enhance students’ understanding and performance in the field and the development of the profession worldwide. Students, fresh chemical engineering graduates, new hires and professionals will find this text very useful. The information the trainee engineer needs to excel and cross the critical but complex stage of transitioning from the university to the real-world engineering practice are explained. Several figures and tables help maximize reader insights into the concept of the discipline.

Foreword The products in the world we use every day require the skill of a chemical/ process engineer, who is trained to ensure the safe and profitable production of the chemicals and materials required to create the products such as food, medicine, fuels, plastics, clean water, clothing and entertainment system. Chemical/process engineers are very much at the forefront of improving the quality of lives of people in a safe environmental manner. Chemical engineering is a fascinating and challenging profession with a wide range of career opportunities. Chemical engineers combine a detailed knowledge of chemistry with understanding principles in order to design, construct and operate chemical process plants in an efficient, safe, sustainable and profitable manner. U. Nnaji provides a comprehensive overview of chemical engineering linking the topics described in a concise and elucidated manner for students, graduates entering the employment market and professionals as a refresher in the subject. He further introduces the pertinent topics of process safety and sustainability with an in-depth knowledge of these subjects, and the application of process simulation in achieving reliable and monitoring operation of the process plants. This book would be most useful to students in this field, graduates and professionals as a refresher in the topics highlighted. I highly recommend this book to these groups of individuals worldwide.

Kayode Coker

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Acknowledgements Let me start by thanking Dr. A. Kayode Coker, one of the world’s foremost chemical engineering author, for reading the manuscript and suggesting additional areas to cover in the book. Thank you so much. This work is a result of two decades industrial experience and over a decade of thoughtful investigation on the subject during weekends and after work periods. Consequently, I encountered several individuals who either supported, encouraged and or proffered useful advice and suggestions. A few notable ones are Lee Webster, Contract Specialist, Onesubsea, Schlumberger; Stephen Lockett, SSA Geomarket PSD, Cameron, Schlumberger; Donald Ibegbu, NCD Manager, Schlumberger; Richard J. Emptage, Technical Director, Integrated Solutions, Early Engineering Engagement; and Rasheed Adebayo, Asset Manager, all Onesubsea, Schlumberger. Many thanks to Omongbai Ashion, Schlumberger Segment Sales Representative who was instrumental in keeping me on my toes during the final proofs of the work. Others are former colleagues and managers at Saipem, who one way or the other supported or encouraged me. They include Guido Nardo, Giuseppe Piana, Joanna Ekwere, Arihar Singh, Ikechukwu Chukwura, Ihuoma Onwubuariri, Davide Rossi, David Egbedi, and Nuzzo Giampiero. In the academia, I would like to thank Professor A. O. Kuye, and Dr. Ifeanyi Edeh, Chemical Engineering Department, University of Port Harcourt; Dr. Ifenyinwa Oranugu, biochemical engineer, Texas, USA and Ralph O. Edokpia, Associate Professor of Industrial Engineering, University of Benin; and many others, for their support. I also want to express my gratitude to Nigerian Society of Chemical Engineers, RIVBAY, for granting me the opportunity to deliver several presentations. Let me also express special thanks to Pastor Stanley Oseji, Dr. Charles Mbaba, Dr. Steve Ayinbuomwan, Hycinth Okonweze, and Louis Obiefuna for their immense support.

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Acknowledgements

I am grateful to Phillip Carmical for his useful feedback and role in directing the publication of this book. To my beautiful wife and kids – thanks for being there for me. The book contains images of processes and equipment from many sources for which I am grateful. Finally, and above all, I want to thank my maker for the inspiration to write this book.

1 Introduction 1.1 Definition of Chemical Engineering Chemical engineering is a branch of engineering concerned with the conceptual, front-end and detailed design, construction, and operation of technologies and plants that perform chemical reactions to solve practical problems or make useful products or provide chemical and environmental solutions for many societal needs. It deals mainly with industrial or commercial processing to produce value-added products from raw materials. The processing of organic (crude oils, natural gas, lumber), inorganic (air, ores, salts) and biological (starches, fats, cellulose) materials into a wide range of useful commodity products, such as plastics, fuels, pharmaceuticals, chemical additives, fibers, fertilizers and foods, is carried out in a controlled process within a framework of environmental sustainability and concern for worker and public safety. Emphasis is on the concept, design, construction and economic operation of equipment that effect the chemical changes and on related research and development.

Figure 1.1.1 Crude Oil Refinery (Image sourced at http://www.filtsep.com/view/16678/ energy-materials-processing-filtration-and-the-fuels-of-the-future/, 2014). Uche Nnaji (ed.) Introduction to Chemical Engineering: For Chemical Engineers and Students, (1–36) © 2019 Scrivener Publishing LLC

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Introduction to Chemical Engineering

Chemical engineering differs from other types of engineering in the application of knowledge of chemistry and biochemistry, in addition to other chemical engineering principles. The discipline generally involves researching, planning, development, evaluation and operation of chemical, biochemical or physical plants and processes; pollution control systems, changes in composition, heat content; analysis of chemical reactions that take place in mixtures; determination of methodologies for the systematic design, control and analysis of processes, evaluating economics, safety and state of aggregation of materials. It also involves analysis of forces that act on matter that leads to the formation of new or conventional chemical materials and products. Slin’ko (2003) [1] elaborates that chemical engineering, as a rule, deals with nonequilibrium chemical engineering systems. Consequently, the analysis and description of such systems present substantial difficulties, which become fundamental as the number of structural elements is increased and the system regresses from equilibrium. The technical aspects of chemical Table 1.1.1 Systems of Interest to Chemical Engineering. Products

Products of interest to chemical engineering include various types of commodity or specialty polymers; pharmaceuticals; a broad array of inorganic, ceramic, or composite materials; chemicals and materials for personal care products (e.g., cellular phones, optic fiber communication networks), medical products, or automobiles; diagnostic devices; drug delivery systems; and others.

Processes for making products

Processes of interest to chemical engineering include a large variety of industrial manufacturing systems used for the production of chemicals and materials (e.g., chemical plants, petrochemical plants, multipurpose pharmaceutical plants, microelectronics fabrication facilities, food processing plants, biomass to fuel conversion plants); ecological subsystems such as the atmosphere; the human body in its entirety and its parts; and energy devices such as batteries and fuel cells.

Applications of interest

Applications of interest to chemical engineering include monitoring and control of air pollution; extraction of fossil energy; life-cycle analysis, design, and production of “green” or sustainable products; diagnostic devices; drug targeting and delivery systems; combustion systems; solar energy; and many others.

Introduction 3 engineering, hence, revolve around managing the behavior of materials and chemical reactions in a closely controlled system—this means predicting and manipulating chemical or biochemical process parameters such as compositions, temperatures, flow rates, and pressures of solids, liquids and gases. Therefore, another way to explain chemical engineering is to state that it is a discipline that deals with the engineering aspects of chemical and biological systems of interest. The special focus within the discipline on process engineering cultivates a systems perspective that makes chemical engineers extremely versatile and capable of handling a wide spectrum of technical problems. Systems of interest most often include products, processes for making them, and applications for using them. Beyond designing, manufacturing, and using products, chemical engineering also includes finding new ways to measure, effectively analyze, and possibly redesign complex systems involving chemical and biological processes.

1.1.2 Chemical Engineers A comprehensive description of the chemical engineer may be to say that he or she is the engineer that designs both products and processes, plans and constructs process hardware, manages operations of processes and researches the solutions to environmental problems. Hence, chemical engineers can be directly involved in research and development and responsible for the design, construction and operation of hardware and processes in varied areas such as energy, biomedicine, electronics, food engineering/ technology, materials, biotechnology, the environment and so on. Details of these areas of expertise are treated in Chapter 3.

Figure 1.1.2 Chemical Engineers maintain and run plants.

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Introduction to Chemical Engineering

Following completion of process and equipment design, chemical engineers, in addition, remain on hand at a production facility to solve problems that occur as the processes continue. When changes occur that upset a running system, chemical engineers analyze samples from the system, looking at parameters such as flow rates, temperatures and pressures to determine where the problem exists. They also work on expanding projects, evaluating new or alternative equipment, and improving existing equipment and processes. Meeting safety, health, and environmental regulations is also a large part of a chemical engineer’s work life. By way of example, the work of the process/chemical engineer can involve any of the following: • Designing a process to produce or refine a given chemical or biochemical product through all the stages from feedstock to output of the finished product. • Designing or sizing the various pieces of equipment or process units which make up this process. • Once a production process is operational, process/chemical engineers can be responsible for managing the production process, improving the efficiency and safety of the process; ensuring products meet the designed specifications, quality standards are maintained, products are produced in a way there can be no harm to the environment; ensuring that the product is produced in a cost-effective manner; seeking ways of optimizing the production process by minimizing cost, recycling energy, reducing man-hours and recovering and utilizing by-products. Generally, success of a large-scale chemical production and the quality of the products are a function of the elaborate but economical design of the process and equipment and precise control of the production processes by chemical engineers. Services provided by chemical engineers in a chemical process industry [4] are summarized in Table 1.1.2. In conclusion, chemical engineers concern themselves with the design of chemical processes and the processing facility where raw materials are turned into valuable products. The necessary skills for chemical engineers encompass all aspects of design, research, management, construction, testing, problem solving (troubleshooting), scale-up, operation, control, and optimization, and require a detailed understanding of the various unit operations and unit processes. The chemical engineer adopts an integrated

Introduction 5

Figure 1.1.3 Chemical engineers design, construct and operate plants (Image sourced at: http://en.wikipedia.org/wiki/Chemical_engineering, 2014).

Table 1.1.2 Services Provided by Chemical Engineers for Process Industries. • • • • • • • • • • • • • • • • • • • •

Feasibility Studies Process Synthesis Designs FEED Studies Process Technical and Economic Evaluation Relief/Flare/Vent Studies Basic Engineering Design Packages Pilot Plant Design, Evaluation and Scale-up Greenfield Plant Designs Plant Commissioning Plant Retrofits Process Modeling and Simulation Process Equipment Specifications Process and Equipment Troubleshooting Cost Estimates Chemical Engineering/Technical Management Process Planning and Scheduling Research and Development Process and Product Development Plant Investment Due Diligence Evaluation Process Design

• • • • • • • • • • • • • • • • • •

Process Evaluations Throughput Debottlenecking Process Optimization Studies Energy Conservation Projects Independent Design Verification Process Reliability Studies Existing Equipment Utilization Studies Technical Bid Reviews Emissions Limits Process Compliance Product Specification Improvement Evaluation Plant Operation Support Plant Construction Support Process Safety Management Turnaround Support Risk Management Program Development Process Hazard Analysis Facilitation Hazards and Operability Studies (HAZOPs) Operations Training

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Introduction to Chemical Engineering

approach to problem solving, applying his or her specialized knowledge in chemistry, mathematics, physics, kinetics, transport phenomena, reactor and other equipment design, separation techniques and thermodynamics to the study of dynamic systems and processes.

1.2 It is the Broadest Branch of Engineering Chemical engineers are sometimes called “universal engineers” because their scientific and technical mastery are wide. Chemical engineering is broader in scope than the other branches of engineering because it draws on the two main engineering basics: mathematics and physics, as well as chemistry and other life sciences, whereas the other branches are based on only the first two. The discipline is essential in fields where processes involve the chemical or physical transformation of matter. It began as a discipline tied to a single industry, the petrochemical industry, but today it is the discipline that interacts with a broad range of industries and technologies. The scope and versatility of a chemical engineering program of study will continue to open many new opportunities for chemical engineers in the future. Chemical engineers have been trained to think at molecular level—in terms of chemical, biological, and physical transformations, as well as at the process and system level. Thus, innovations have moved from macroscopic toward microscopic, and to the nano and molecular scales. The focus of chemical engineering on molecular transformations, quantitative analysis, processes and multiscale treatment of problems makes the discipline exceptional and provides an ideal basis for productive interactions with a wide range of other science and engineering disciplines at boundaries that are among the most exhilarating technology areas of our time. The field synthesizes knowledge from several disciplines (multidisciplinary) and interacts with researchers from multiple disciplines (interdisciplinary) as illustrated in Figure 1.4.3. The engineering discipline has demonstrated a unique ability to synthesis diverse forms of knowledge from applied sciences and other engineering disciplines into cohesive and effective solutions for many societal needs. This integrative capacity is at the nucleus of the discipline’s reason for existence and is its most unique characteristics. A study group in the US reports that chemical sciences and engineering together have resulted in the most enabling science/technology combination to underpin technology development in every industrial sector.

Introduction 7 No other technology is as prevalent and influential as chemical technology in all industries. The field is a lifelong learning experience because it is constantly evolving. While the principles learned in college and university will always be a vital part of a chemical engineer’s repertoire (range of work), chemical engineering can change with new discoveries. Given the spread of the discipline, chemical engineers later in their careers might find themselves working in an industry that did not exist when they graduated.

1.3 Chemical Engineering – a General Purpose Technology Indeed, a discipline that provides the concepts and the methodologies to generate new or improved technologies over a wide range of downstream economic activity may be thought of as an even purer or higher-order, of General-Purpose-Technology (GPT) [5]. This should not be contentious. A steam engine or a dynamo is not a technology; they are examples of tangible capital equipment. “Steam” or “electricity”, which means bodies of knowledge about how to produce steam or electricity, respectively, and to use them as sources of power or light, in steam engines or dynamos, are technologies. Similarly, chemical engineering is a body of knowledge about the design of certain technologies. More specifically chemical engineering is a body of knowledge about the design of process plants to produce chemical or other products whose production involves chemical transformations. Chemical engineering has been considered a GPT since it provides essential guidance to the design of a very wide range of plants. Furthermore, there has been both a vertical and horizontal dimension to the outcomes that were generated. The emergence of chemical engineering meant that downstream sectors experienced lower invention costs. But, in addition, there was a powerful horizontal outcome, in the sense that the vast market for petroleum has shaped the development of petrochemicals through the intermediation of chemical engineering.

1.4 Relationship Between Chemical Engineering and the Science of Chemistry Chemistry is the branch of natural science dealing with the composition of substances and their properties and reactions while engineering is the application of science to commerce or industry. Hence, chemical engineering is the use of knowledge about properties and reactions (chemical

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Introduction to Chemical Engineering

knowledge), in addition to other scientific knowledge, to solve practical, real-world problems. To understand the relationship between chemical engineering and the science of chemistry, it is necessary to deal with a widely held view that chemical engineering, like other engineering disciplines, is simply applied science—in this case applied chemistry. Hence, the design and construction of plants dedicated to large-scale chemical processing activities entail an entirely different set of activities and capabilities than those that generate the new chemical entities. This activity begins with laboratory experiment and is followed by implementation of the technology to full-scale production. Such activities as mixing, heating, and contaminant control, which can be carried out with great precision in the laboratory, are immensely more difficult to handle in large-scale operations. By applying critical variables discovered during laboratory experiments, chemical engineers typically anticipate and proffer solutions to scale up problems. Chemical engineers are trained to work quantitatively, using data to support plant design; for example, the number of theoretical plates can affect batch distillations. Chemical engineers do not have as much laboratory flexibility but can be equally creative through hypothesis, prediction and use of scenarios. [6] Ordinary mixing which is carried out in laboratories using laboratory vessels and equipment becomes a complex science when performed during scale up in stirred tanks. This operation is affected by many equipmentand process-related parameters such as type of mixer, agitator speeds (1000rpm) and/or specific mixing duty the process requires. Chemical engineers design processes to ensure the most economical operation. Therefore, economic considerations must obviously play a critical role in the design process. This means that the entire production chain must be planned and controlled for costs. Cost or economic considerations become decisive in an industrial context, and cost considerations are intimately connected to decisions concerning optimal scale plant. Practitioners in this field of engineering have been much more deeply involved in dealing with cost considerations than other engineering professions. This is an interesting feature of chemical engineering. Thus, when a new chemical entity is discovered, an entirely new question, one that is distant from the scientific context of the laboratory, surfaces. How does one go about producing it? A chemical process plant is far from a scaled-up version of the original laboratory equipment. A simple, multiple enlargement of the dimensions of small-scale experimental equipment would be likely to yield disastrous results.

Introduction 9 Experimental equipment may have been made of glass or porcelain. A manufacturing plant will definitely have to be constructed of very different materials. Producing a given useful product by the ton is very different from producing by the ounce. This really is what accounts for the unique importance of a pilot plant, which may be thought of as a device for translating the findings of laboratory research into technically viable and economically efficient large-scale production process. The translation (of laboratory findings), on the contrary, requires competences that are unlikely to exist at the experimental research level – these include a knowledge of mechanical engineering, chemistry and physics and an understanding of the underlying economics of likely alternative engineering approaches.

Chemical Engineering

Figure 1.4.1 Chemical Engineering Illustration (Image sourced at University of Pretoria Chemical Engineering Department Website: sitefiles/image/44/2063/chemeng_en.jpg, 2017).

Basically, chemistry aims to realize the required functions by synthesizing new materials, and this results in increasing the number of chemical compounds, but chemical engineering can reduce the number of chemical elements by controlling the shape and nanostructure of materials [8]. Hence, science mainly focuses on the useful product to make, and technology and engineering develops how to make it. Also, a chemical engineer can both simplify and complicate “showcase” reactions for an economic advantage. Consequently, apart from scaling-up a laboratory finding by technical means, chemical engineers also engineer a system that may improve reaction efficiency. For example, operating at a higher pressure or temperature makes several reactions easier; ammonia, for example, is simply produced from its component

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Introduction to Chemical Engineering

elements in a high-pressure reactor. On the other hand, reactions with a low yield can be recycled continuously, which would be complex, strenuous work if done by hand in the laboratory. It is not unusual to build 6-step, or even 12-step evaporators to reuse the vaporization energy for an economic advantage. In contrast, laboratory chemists evaporate samples in a single step. However, chemistry brings chemical engineers and chemists together. This is because a chemical process is dependent on the intrinsic chemistry, which is independent of scale. Thus, whether a molecule is in a 15ml flask or a 20m3 vessel, it will still behave as determined by its surroundings.

1.4.1 Chemical Engineers Take Chemistry Out of the Laboratory and Into the World The principles of chemistry, mathematics, and physics are applied by chemical engineers to design and operate large-scale chemical manufacturing processes. They translate processes developed in the laboratory and adapt production methods from the small scale in the laboratory into large-scale practical applications for the production of such products as chemicals, pharmaceuticals, plastics, medicines, detergents, and fuels; design plants to maximize yield and minimize costs; evaluate plant operations for performance and product quality.

Chemistry

Engineering design

Large Scale Production

Figure 1.4.2 From Chemistry Laboratory to Large-Scale Production.

In the chemical manufacturing sector, the chemist may be the main agent in the development of new products, but the design of the industrial manufacturing technology for new products, as well as improving the technologies for manufacturing old products, is the chemical engineers’

Introduction 11 expertise. Hence, they develop technologies that will utilize network of organizations to take processes from chemists’ ideas into production. Imagine designing a chemical plant that produces 2.5*105 metric tonnes per annum of 4-hydroxy-2-butanone by dehydrogenation of 2, 4-hydroxy butanol. This scale up requires development of a technology (the process) which will include various large equipment (hardware) which design also will involve applying engineering principles. Take for example, a chemical engineer who works in an area that produces hexamethylene diamine—a molecule used in the production of nylon. His or her main work may involve applying chemists’ findings to large-scale production. Hence, this engineer takes up what a chemist does—synthesize a small amount of a material—and scales it up to the level of producing several hundred tons per day. This process includes determining how to separate the desired product from its impurities or by-products. Other activities of the engineer may focus on chemical kinetics, fluid flow and heat transfer on a large scale—techniques that do not pose problem with smaller reactions in beakers. Consequently, the engineer would ultimately design equipment that will accommodate these concerns.

Design, Construction and Operation of Plants for large scale Production of Laboratory Findings

Chemical Engineers

Laboratory Research/Findings

Discovery Chemists

Biochemists

Pharmacists

Microbiologists

Figure 1.4.3 Relationship between Chemical Engineers and other Scientists.

Other Natural Scientists

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Introduction to Chemical Engineering

Figure 1.4.4 A Chemist Working in the Laboratory (Image sourced at: http://bobtrade. net/more-details/pages-under-slider/popular-courses/chemical-engineering/, 2012).

Figure 1.4.5 A Chemical Engineer in the Plant.

1.5 Historical Development of Chemical Engineering The key events and activities of some people that led to the development and emergence of chemical engineering are succinctly discussed in this section. The chemical engineering discipline unarguably can be said to have evolved systematically in the following way:

Introduction 13 1900 1925 1950 1975

• Industrial Chemistry and Mechanical Engineering • Unit Operations • Chemical Engineering Science • Chemical Systems Engineering

Figure 1.5.1 Evolution of Chemical Engineering.

1.5.1 Industrial Chemistry and Mechanical Engineering Sulfuric Acid Production The relationship between chemistry and chemical engineering has been established in section 1.4 of this chapter. Thus, it will not be surprising that development of chemical engineering is being traced to industrial chemistry. Industrial chemistry was being practiced in the 1800s but it was not until the 1880s that engineering rudiments required to control chemical processes were being recognized as a distinct professional activity. Historians agree that chemical engineering was developed in the twentieth century. By this time, organic chemistry was almost a century old, and inorganic chemistry was far older. Sulfuric acid was first among certain chemicals that became necessary to sustain economic growth in the eighteenth century as the Industrial Revolution soared. In fact, a nation’s industrial might could be gauged solely by the vigor of its sulfuric acid industry. Hence the need for optimal production of sulfuric acid arose. The Lead-Chamber Method, which required air, water, sulfur dioxide, a nitrate, and a large lead container, was being used (since 1749) to create sulfuric acid. Nitrate was always the most expensive because they are lost to the atmosphere at the final stage of the process in the form of nitric oxide; hence, necessitating a make-up stream of fresh nitrate. This extra nitrate had to be imported in the form of sodium nitrate from Chile. John Glover helped solve this problem in 1859, by introducing a mass transfer tower to recover the nitrate being lost to the atmosphere. Sulfuric acid at the stage where it still contains nitrates was trickled downward against upward flowing burner gases in the tower. By so doing, the nitric oxide could be reused when the flowing gases which had previously absorbed lost nitric oxide were recycled back into the lead chamber. Leblanc and Solvay Process Nicolas Leblanc invented a process for the production of soda ash (sodium carbonate, Na2CO3) and potash (potassium carbonate, K2CO3), collectively called alkali. The process became known as Le Blanc process. These Alkali

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Introduction to Chemical Engineering

compounds were used in a wide range of products including glass, soap, and textiles and were as a result in high demand. The process yields undesirable by-gaseous products. Problems caused to the environment by the by-gaseous products (calcium sulfide), health effects, and elaborate and often complex engineering efforts ushered in the Solvay process (in 1873) which replaced Leblanc’s method for producing Alkali. Ernest Solvay invented this process. George E. Davis After 1850, “chemical engineering” describing the use of mechanical equipment in chemical industries became common vocabulary in England. George Davis is regarded as the founding father of chemical engineering by many authors. He was a heretofore unremarkable Alkali Inspector from the Midlands region of England. His career in chemistry started in a chemical industry in Manchester. He then worked as a chemist at Brearley and Sons for three years; then as an inspector for the Alkali Act of 1863. In 1872 he was employed as manager at the Lichfield chemical company in Staffordshire. Notable in his work at the time is the tallest chimney in the UK, with a height of more than 200 feet (61m). In 1880 George Davis acted upon ideas of a discipline of chemical engineering and proposed the formation of a “Society of Chemical Engineers”. The attempt was unsuccessful, yet he continued to boldly promote chemical engineering. In 1884 Davis became an independent consultant applying and synthesizing the chemical knowledge he had accumulated over the years. As an industrial consultant and inspector, Davis visited a great variety of chemical processing plants. He was keen to identify broad features in common to all chemical factories. Hence, he published in 1887 a series of 12 lectures on chemical engineering, at Manchester Technical School (which became University of Manchester Institute of Science and Technology). He proposed a chemical engineering course which would be organized around individual chemical operations, later to be called “unit operations.” Davis explored these operations empirically and presented operating practices in use by the British chemical industry. Consequently, some felt his lectures simply shared English know-how with the rest of the world. His effort once more fizzled in Britain but his dream was eventually established in America. One would assume here that Davis failed in establishing chemical engineering in British universities because to develop a discipline emphasizing general principles was more suited to universities than commercial firms. Academic and government attitudes therefore may have played a role. Another suggested reason why Davis’s proposal was not fully accepted in Britain was because Henry Edward Armstrong, who started a degree course in chemical engineering three years earlier,

Introduction 15

George Davis

Fritz Haber

Carl Bosch

Figure 1.5.2 Men that Steered Chemical Engineering Discipline (Photo Courtesy of BASF at: https://www.thechemicalengineer.com, 2017).

could not make it. Armstrong’s course did not succeed because employers would rather employ a chemist and a mechanical engineer than a chemical engineer, at that time. Davis expanded on the 12 lectures, and 14 years later authored a book, A Handbook of Chemical Engineering, published in 1901. Emergence of Chemical Engineering Degree Lewis Norton, a chemistry professor at the Massachusetts Institute of Technology (MIT) in 1888 initiated the first four-year bachelor program in chemical engineering entitled “Course X” (ten); just a few months after the lectures of George Davis. Norton’s course was contemporaneous and simply merged chemistry and engineering subjects (mechanical engineering). University of Pennsylvania and Tulane University and other colleges soon followed MIT’s lead by initiating their own four-year programs. However, at this early stage, chemical engineering was tailored to fulfill the needs of the chemical industry. Practitioners of chemical engineering at the time faced difficulty convincing engineers that they were engineers and chemists that they were not chemists. In 1905, unit operations was introduced into the course by William Hultz Walker and by the 1920s this had become an important aspect of the discipline of chemical engineering at MIT, other US universities and Imperial college London. The discipline gradually began to metamorphose into an independent profession when the American Institute of Chemical Engineers (AIChE) was formed in 1908. The AIChE defined chemical engineering to be a separate science which is based on unit operations. During the First World War, the British army faced shortage of munition (stock of shells) in the Great Shell crisis. It was at this time that Kenneth Bingham Quinan designed and led the large-scale manufacture of efficient (high) explosives and propellants. The success of this effort eventually gave rise to formation of the Institution of

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Introduction to Chemical Engineering

Chemical Engineers (IChemE) in Britain in 1922. Quinan later became the first vice president of the institution.

Figure 1.5.3 Kenneth Bingham Quinan (Picture sourced at: https://www.thechemicalengi neer.com/features/cewctw-keith-bingham-quinan-and-colleagues-an-explosive-start, 2017).

But by the 1940s, it had become obvious that unit operations alone were not sufficient to develop chemical reactors; hence transport phenomena, process system engineering and other novel concepts started to gain much focus. Thermodynamics, which included properties of gases and liquids, and applications of both first and second laws, were also introduced at the time. Furthermore, it is worth stating that, surprisingly, chemical engineering did not come to Germany early, yet industrial chemists and mechanical engineers in that country had been having strong collaboration, leading to invention and industrialization of the Haber-Bosch process in early 1908 to 1911 [10]. Fritz Haber, who was a chemist, invented a method for synthesizing ammonia and this requires temperatures up to 500oC and pressures up to 1000 atmospheres [11]. Because such high temperature and pressure were enormously difficult to attain on the industrial scale, his invention might have remained a laboratory curiosity. Hence, Carl Bosch, a mechanical engineer, scaled up the process leading to ammonia production. Both received the Nobel Prize award. The chemical engineering degree program at the time was developed to fulfill the need of chemical process industries (CPI). An academic curriculum was established to train students that can fit into the industry immediately after graduation, to serve this need. Meanwhile, competition amongst various chemical companies around the world was intense. Some dishonest individuals even did many unethical acts, which included trying to outdo one another

Introduction 17 by bribing agents to contaminate others’ products. Yet this did not provide the much-needed competitive edge. Competition, however, contributed to reshaping the chemical engineering curriculum. By this time companies started thinking of ways of lowering cost through optimizing production process to beat competition. This led to innovative ideas such as continuous production process, by-product recycling, and other critical optimization techniques and automatic controls to continuous processing in many chemical industries. At this stage, an entirely new generation of engineering practitioners that had distinct dexterity was born. CPI’s would now have the opportunity of employing chemical engineering graduates over mechanical engineering or chemistry graduates. Up until date, process optimization remains the core drive of every chemical process engineer. Success of these innovative ideas led to some CPI’s establishing a dedicated research and development (R&D) department for continuous study of more ways of lowering cost. For these companies that are inclined to innovation, another breed of chemical engineering graduate is required. A kind of chemical engineering science graduates and chemical engineering technology graduates were hence born. Over time academic research has had a strong push toward science, largely due to the emergence of areas like nanotechnology and biotechnology, which consequently has caused some disconnect between academia and industry. The evolution of chemical engineering is summarized in Table 1.5.1. Table 1.5.1 Chronological History of the Emergence of Chemical Engineering. 1859

Sulfuric Acid Production

John Glover helped solve problem of losing nitrate to the atmosphere, by introducing a mass transfer tower to recover the nitrate.

1873

Le Blanc and Solvay Process

Ernest Solvay invented a process that helped solve the problem caused to the environment by the by-gaseous products from Nicolas Leblanc’s process for alkali production.

1880

George Davis

George Davis, regarded as the founding father of chemical engineering, acted upon ideas of a discipline of chemical engineering and proposed the formation of a “Society of Chemical Engineers”. The attempt was unsuccessful. (Continued)

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Table 1.5.1 Chronological History of the Emergence of Chemical Engineering. (Continued) 1884

George Davis

George Davis published in 1887 a series of 12 lectures on chemical engineering, at Manchester Technical School (which became University of Manchester Institute of Science and Technology). He proposed a chemical engineering course which would be organized around individual chemical operations, later to be called “unit operations.” Davis explored these operations empirically and presented operating practices in use by the British chemical industry. This dream fizzled in Britain but was eventually established in America.

1888

Lewis Norton

Lewis Norton, a chemistry professor at the Massachusetts Institute of Technology (MIT) initiated the first four-year bachelor program in chemical engineering entitled “Course X” (ten); just a few months after the lectures of George Davis. Norton’s course was contemporaneous and simply merged chemistry and engineering subjects.

1908

AIChE

American Institute of Chemical Engineers (AIChE) was formed.

1908-1911

Haber-Bosch Process

In Germany, Carl Bosch, a mechanical engineer, scaled up a process developed by Fritz Haber, a chemist, leading to ammonia production. Both received the Nobel Prize for their work in overcoming the chemical and engineering problems posed by the use of large-scale, continuous-flow, highpressure technology.

1916

Arthur Dehon Little

In America, Arthur Little propounded the concept of “unit operations” to explain industrial chemistry processes. (Continued)

Introduction 19 Table 1.5.1 Chronological History of the Emergence of Chemical Engineering. (Continued) 1922

IChemE

Institution of Chemical Engineers (IChemE, Britain) was formed.

1924

William H. Walker, Warren K. Lewis and William H. McAdams

William H. Walker, Warren K. Lewis and William H. McAdams wrote the book, The Principles of Chemical Engineering. They explained the variety of chemical industries processes which follow the same physical laws and summed up these similar processes into unit operations. This became the standard textbook for chemical engineering for decades.

1940s

Transport Phenomena, Process System Engineering and others

It became obvious that unit operations alone are not sufficient to develop chemical reactors, hence transport phenomena, process system engineering and other novel concepts started to gain much focus.

1.5.2 Unit Operations Historically, the chemical engineering concept systematically evolved from industrial chemistry to unit operations, then to chemical engineering science and then to chemical systems engineering. Effectively, the emergence of distinct knowledge for the discipline began when Arthur D. Little started the concept of unit operations in the early nineteenth century. He understood that the principles are the same for different industrial processes. Hence, various unit operations were being identified and developed. For example, the physical separations such as distillation, absorption, and extraction, in which the principles of mass transfer, fluid dynamics, and heat transfer were combined in equipment design (process unit), were developed. The concept of unit operation has remained throughout the phase of chemical engineering growth and has even been used to understand the way the human body functions. The chemical and physical aspects of chemical engineering are known as unit processes and unit operations, respectively.

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Introduction to Chemical Engineering

In 1923, William H. Walker, Warren K. Lewis and William H. McAdams leveraged on the work of Arthur D. Little and wrote the book The Principles of Chemical Engineering. The authors explained in the book that unit operation follows the same physical laws and may be used in all chemical industries. The unit operations thus became the fundamental principles of chemical engineering. Unit operations method was then being used to tackle the fundamental problems of the quantitative control of large masses of material in reaction and to design cost-effective industrial-scale processes for chemical reactions. The knowledge is that industrial chemical-manufacturing processes can be resolved into a relatively few units, each of which has a definite function and each of which is used repeatedly in different kinds of processes. The unit operations are steps like filtration and clarification, heat exchange, distillation, screening, magnetic separation, and flotation. They can also include mechanical operations such as mixing or crushing, or thermal operations such as liquefaction or refrigeration. A typical process unit is shown in Figure 1.5.4. Chemical engineering unit operations consist of five classes:

Mechanical processes Mass transfer processes

• including crushing and pulverization, solids transportation, screening and sieving • including distillation, gas absorption, extraction, adsorption, drying

Fluid flow processes

• including filtration, fluids transportation, solids fluidization

Thermodynamic processes

• including refrigeration, gas liquefaction

Heat transfer processes

• including condensation, evaporation

Chemical engineering unit operations also fall into the following categories: Combination • Mixing

Separation • Distillation

Reaction • Chemical Reaction

Introduction 21 The following are some chemical engineering unit operations and techniques being applied in chemical process industries:

Table 1.5.2 Chemical Engineering Unit Operations and Techniques. Petrochemical

Solution polymerizations Fluid bed polymerizations Condensation polymerizations Specialty polymers and monomers recovery, etc.

Pharmaceutical

Separation Chiral selectivity Parallel synthesis Multi-step processing, etc.

Laboratory

Catalyst development Multi-purpose mini-plants Supercritical wet oxidation Batch to continuous flow scale-up, etc.

Food

Solids blending Starch processing Supercritical extractions Hydrogenation/dehydrogenation, etc.

Energy

Alternative fuel Syngas/Fuel cell Supercritical processing Liquefaction/upgrading, etc.

Refining

Reforming Hydrocracking Isomerization Hydrotreating, etc.

Chemical

Amination Alkylation Carboxylation Crystal growth, etc.

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Introduction to Chemical Engineering

Figure 1.5.4 A Process unit of petrochemical plant under construction at Lagos.

1.5.3 Chemical Engineering Science The so-called engineering science approach in the discipline emerged in the 1950s and 60s. This is the second paradigm of chemical engineering, unit operation being the first. (Refer to Figure 1.5.1.) The chemical engineering science involves thinking about those chemical processes very much like natural scientists do with natural phenomena. Chemical engineers hence treated these processes in the quantitative way and exposed the laws controlling them in relation with the materials and equipment concerned in them. Chemical engineering science therefore utilizes mass, momentum, and energy transfer along with thermodynamics and chemical kinetics to analyze and improve on “unit operations”, such as distillation, mixing, and biological processes, and so on. However, the idea of engineering science was not unique to chemical engineering as other engineering disciplines also began to incorporate similar ideas to solve problems in their domain at about the same time. This approach led to a chemical engineering curriculum, at both the undergraduate and graduate levels, that is an exceptional blend of chemistry, physics and mathematics. The chemical engineers educated in this manner could effectively develop, design and operate complex chemical and refining processes that typically produced commodity chemicals and a variety of products derived from petroleum and other feedstocks. Producing petroleum at large scale provided chemical engineers the opportunity to

Introduction 23 apply their design and problem-solving capabilities that were critical to the creation of some entirely new industries.

1.5.4 Chemical Systems Engineering Chemical systems engineering is subdivided into process design, process control and process operations. The early 1960s saw an explosive growth period for the chemical process system. Three factors were responsible: the need for less costly processes due to rapid growth of chemical industry; to optimize production process, a science-based description of the fundamental phenomena in unit operations became necessary; and the computer also became necessary to produce more reliable quantitative description of process units. Hence, by the 1960s chemical engineers could put mathematical descriptions of reactions, their rates, thermo-physical properties of pure materials and mixtures, equilibrium and rate processes, and could integrate these as functions of equipment design parameters and the process operating conditions.

1.6 Anatomy of a Chemical Engineering Plant 1.6.1 Overview A chemical or gas plant is an industrial process plant that manufactures (or otherwise blends or processes) chemicals (gaseous, solid or liquid) or natural gas, usually on a large scale. A chemical or gas plant is usually located near the source of feedstock or raw materials. For example, petrochemical plants are usually located adjacent to or near an oil refinery to minimize transportation costs for the feedstocks produced by the refinery. However, specialty chemical plants which are usually much smaller are not as sensitive to location. A variety of chemicals can be produced from one chemical plant. Safety is a major concern in chemicals or gas processing plant. High safety standards are maintained as mistakes at a chemical plant can be very dangerous and chemical plants are susceptible to acts of sabotage and terrorism. A chemical plant can become a chemical bomb as in the case of DuPont Yerkes chemical plant explosion, T2 laboratories explosion (US), BP refinery explosion, and so on. Chemical plants, consequently, are usually required to undergo regular safety checks to ensure that the plant is operating safely, and the facilities have far-reaching security to protect the plant from external threats.

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Introduction to Chemical Engineering

Typical productions of chemical and gas plants are: • • • • • •

Pharmaceutical Agriochemicals Food & beverages Sheet Processes Textiles Treated and compressed hydrocarbon gases

The overall objective of a chemical, biochemical or gas plant is to create new material wealth via the physical, chemical or biological transformation and or separation of materials. Chemical plants use special equipment, units, and technology in the processes.

Figure 1.6.1 Inside View of a Gas Processing Plant.

Figure 1.6.2 Front View of a Gas Processing Plant.

Introduction 25 The figure below shows the various features of a process plant. These are considered in no order in the following sections.

Laboratoryy Warehouse and Storage

Power/Electrical Unit Pumps, Piping and Valves

Fire Fighting Unit

Atmospheric Storage Tanks

Office Buildings

Anatomy of a Process Plant

Workshop and Lay-down Area

Process Units

Fire and Atmospheric Ventilation Process Control

Figure 1.6.3 Anatomy of a Process Plant.

1.6.2 Process Units A typical chemical or gas plant has large vessels, equipment or sections called process units that are interconnected by process piping or other material-moving equipment which can carry streams of material. The streams of material in the process piping are usually fluids which can be gas or liquid and sometimes solids or mixtures of both solids and liquids such as slurries. Various kinds of unit operations are conducted in different types of these units. The units may operate at ambient temperature or pressure, but many units operate at higher or lower temperatures or pressures. Vessels in chemical plants are often cylindrical with rounded ends, with body thickness which can be suited to hold high pressure. In a chemical plant, the main unit is known as a reactor; this is where chemical reaction takes place. Reactants are converted into various kinds of useful outputs in a chemical reactor. Chemical reactors may be packed beds and may have solid heterogeneous catalysts which stay in the reactors as fluids move through. Some can be batch reactors, while some are continuous reactors. Continuous reactors are predominant in a process plant because of

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Introduction to Chemical Engineering

continuous operation. There are other units or subunits in a process plant, which serve various purposes. They include mixing (including dissolving), separation, drying, heating, cooling, or some combination of these. Chemical reactors usually have stirring for mixing and heating or cooling going on in them. Reactions within a reactor can generate or absorb heat from the surrounding. The heat generated in a reactor can be collected and used to heat up another unit. When designing plants on a large scale, heat produced or absorbed by chemical reactions should be considered. In case of a petroleum refinery, a CO2 boiler is used to generate the steam that is used to raise the temperature of any unit, where required. For a biochemical plant, the reactor may contain organism cultures for biochemical processes such as fermentation or enzyme production. Products or output of a chemical reactor may include a mixture of wanted and unwanted products. Separator is another unit that does the work of separated process products into various factions. Separation processes include filtration, settling (sedimentation), extraction or leaching, distillation, recrystallization or precipitation. Others are reverse osmosis, drying, and adsorption. For a unit requiring direct heating, a furnace can be erected. Heat exchangers are used to indirectly heat or cool a process unit. The amount of primary feedstock or product per unit of time which a process plant or unit can process is referred to as the capacity of that plant or unit. For examples, the capacity of a petroleum refinery may be given in terms of barrels of crude oil refined per day; alternatively, chemical plant capacity may be given in tons of product produced per day. In actual dayto-day operation, a plant (or unit) will operate at a percentage of its full capacity.

Figure 1.6.4 Plant Gas Metering unit.

Introduction 27

1.6.3 Process Interconnecting Piping (Pumps, Piping & Valves) All plant units are usually arranged in a logical manner to take care of material flow, statutory requirements and good engineering practices. Feedstock and steams of material in and out of a process unit are carried through process interconnecting piping. However, final products from one plant may be intermediate chemicals used as feedstock in another plant for further processing. For example, some products from an oil refinery may be used as feedstock in petrochemical plants. These products are transported through process piping.

Figure 1.6.5 Process Interconnecting Piping.

The piping and tubing come in various diameter and sizes. Also, there are various types of valves for controlling or stopping flow in the pipes. Pumps are used to move or pressurize liquid and compressors for pressurizing or moving gases. The size and construction of process and utility piping depend on the type of service, pressure, temperature, and nature of the products. Vent, drain, and sample connections are provided on piping, as well as provisions for blanking. The piping can be covered with insulating materials to prevent loss of heat to the surrounding where applicable.

1.6.4 Power/Electrical Unit A chemical plant is usually powered by gas or a steam-driven electrical system. The interesting aspect of a chemical plant is that it can utilize the heat

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Introduction to Chemical Engineering

generated within a unit of the plant to produce steam which can drive a steam turbine of a power unit. Also, a gas generated as a by-product can be used to drive a gas turbine of a power unit. Electricity hence can be produced in the same plant. If exhaust heat from the power generating system is not needed in the main process, it can be used to drive exhaust steam turbines (dual cycle) for additional efficiency. A gas driven power system and the power control section of a plant is shown in the following Figure 1.6.6.

Figure 1.6.6 Gas Turbine Power Generator and Power Control Section of a Plant.

1.6.5 Process Laboratory A process plant also has a laboratory section where various testing, quality checks, researches and analysis are carried out. This is where chemists, biologists and chemical engineers work together as a team. Analysis done in the laboratory can include chemical or biochemical analysis or determination of physical properties. Intermediate and final products can also be routinely analyzed in a process laboratory to ensure quality specifications are met. Non-routine samples may be taken and analyzed for investigating plant process problems also.

Figure 1.6.7 Typical Chemical Plant Laboratory (Image Sourced at: chem-eng-net.com, 2012).

Introduction 29

1.6.6 Process Control In a chemical plant, information gathered automatically from various field instruments (see Figure 1.6.10) in the plant is used to run and control operations of the plant. These field instruments—temperature and pressure detectors, level detectors and so on, are linked to a central control unit. The main function of the control system is to make sure the production, processing and utility systems operate efficiently and safely within design constraints and alarm limits. Initially, pneumatic controls were sometimes used. Electrical controls are now common. Very small installations may use hydraulic or pneumatic control systems, but larger plants with up to 30,000 signals to and from the process require a dedicated control system and building. The purpose of this system is to read values from a large number of sensors, run programs to monitor the process and control valves, switches and so on, to control the process. Such plant will have a control room (see Figure 1.6.9) with displays of parameters such as key temperatures, pressures, fluid flow rates and levels, operating positions of key valves, pumps and other equipment, and so on. Some chemical engineering graduates specialize as process control engineers and are employed to work in this unit. Process control is a statistics and engineering discipline that deals with architecture, mechanism, and algorithms for controlling the output of a given process. A commonly used control device called a Programmable Logic Controller (PLC) is used to read a set of digital and analog inputs, apply a set of logic statements, and generate a set of analog and digital outputs. For example, logical statements would compare the setpoint to the input temperature and determine whether more or less of heating was necessary to keep the temperature constant. A PLC output would then either open or close the

Figure 1.6.8 An Automation Engineer Inspecting Cable Terminations.

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Introduction to Chemical Engineering

process valve, an incremental amount, depending on whether more or less process fluid was required. Larger, more complex systems can be controlled by a Distributed Control System (DCS) or Supervisory Control and Data Acquisition (SCADA) system. Contemporary distributed control systems (DCS) connect data from sensors, control systems and operator panels.

Figure 1.6.9 Process Control Room.

In practice, process control systems can be characterized as one or more of the following forms:

Discrete

• Involves the production of discrete pieces of product. This can be found in manufacturing, motion and packaging applications. For example, robotic assembly, such as that are found in automotive production, can be characterized as discrete process control.

Batch

• Batch processes are generally used to produce a relatively low to intermediate quantity of product per year. Some applications will require that definite quantities of raw materials be combined in precise ways for a period of time to produce an intermediate or end result. Adhesives and glues for example, normally require the mixing of raw materials in a heated vessel for a period of time to form a given quantity of end product. Also, production of drugs, foods, beverages, etc., are other batch processes. Drugs for instance, come in drum containers, after production.

Continuous

• Sometimes the materials being processed will be in continuous motion, undergoing chemical reactions or subjected to mechanical or heat treatment and uninterrupted in time. This is known as continuous process. The production of fuels, gas, chemicals and plastics, are continuous practices. Continuous chemical processes are used to produce very large quantities of product per year.

Introduction 31 Pressure Transmitter

Pressure Indicator/Gauge

Temperature Indicator

Shut-down Valve

Pressure Transmitter

Pressure Control Valve

Temperature Transmitter

Level Transmitter

Figure 1.6.10 Process Control Field Instruments.

1.6.7 Storage Tanks Process plants, furthermore, usually have a location where atmospheric storage and pressure storage tanks are located. These tanks are used in the plant for storage of crudes, intermediate hydrocarbons (during the process), chemicals, liquid raw materials (feedstock), waste products and intermediate or final products. Tanks are also provided for fire water, process and treatment water, petroleum products, acids, additives, and other chemicals. The types, construction, capacity and location of tanks depend on their use and materials stored in them. Refer to Figure 1.6.11 to see a typical process storage tank on the top left corner. Storage tanks commonly have control mounted instruments. For example, level indicators are installed on storage tanks to show how full they are. Some chemical or process engineers specialize just in designing storage tanks. The design may seem simple but often requires application

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Introduction to Chemical Engineering

of very complex engineering techniques. Storage tanks can store hazardous or highly inflammable substances, hence fluid physio-chemical properties usually form part of the input data required for process tank design. Poorly designed storage tank can sheer or rupture or even explode. If the tank contains hazardous or inflammable substances, the incident can be catastrophic. Stairs are commonly constructed round a storage tank for personnel to reach the top of the tank for sampling, inspection, or maintenance. The storage tank can be on a concrete structural foundation or steel structure foundation.

Storage Tank

Gate Valve

Pipe and Vessel Carrying Steel Structure

Ball Valves

Figure 1.6.11 Plant units and valves.

1.6.8 Flare and Atmospheric Ventilation Unit Another vital section of a process plant, especially a gas processing plant, is the flare and atmospheric ventilation unit. The purpose of the flare and vent systems is to provide safe discharge and disposal of vapor (gases) and liquids resulting from: • Spill-off flaring from the product stabilization system (for example, oil condensate). • Relief of excess pressure caused by process upset conditions and thermal expansion. • Depressurization either in response to an emergency situation or as part of a normal operating procedure. • Venting from equipment operating close to atmospheric pressure (for example, atmospheric tanks).

Introduction 33

Figure 1.6.12 Flare Unit of a Plant.

For safety reasons a stack is used to elevate the flare. The flare must be located so that it does not present a hazard to surrounding workers and facilities and also the neighboring community. In the flare, air may tend to flow back into a flare stack due to wind or thermal contraction of stack gases and create an explosion potential. To prevent this, a gas seal is typically installed in the flare stack. The burner tip or flare tip is designed to give environmentally acceptable combustion of the vent gas over the flare system’s capacity range. The burner tips are normally proprietary (see Section 5.2.3.8) in design. Consideration is given to flame stability, ignition reliability, and noise suppression. Flare system control can be completely automated and controlled from the central control room or completely manual. Components of a flare system which can be controlled automatically include the auxiliary gas, steam injection, and the ignition system. Pressure-relief systems control vapors and liquids that are released by pressure-relieving mounted devices and blowdowns. Pressure relief is an automatic, planned release when operating pressure reaches a predetermined level in any of the installed pressure vessels. Blowdown normally refers to the intentional release of material, such as blowdowns from process unit startups, shutdowns, furnace blowdowns, and emergencies. Also, vapor depressuring is the rapid removal of vapors from pressure vessels in case of fire. Rupture disc set at a higher pressure than the relief valve can be used to accomplish this. Safety relief valves, used for air, steam, and gas as well as for vapor and liquid, allow the valve to open in proportion to the increase in pressure over the normal operating pressure. Safety valves

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designed primarily to release high volumes of steam usually pop open to full capacity. The overpressure needed to open liquid-relief valves where large-volume discharge is not required increases as the valve lifts due to increased spring resistance. Pilot-operated safety relief valves, with up to six times the capacity of normal relief valves, are used where tighter sealing and larger volume discharges are required. Fluids from blowdown piping and or discharge lines are usually pumped to a knock-out drum separator, where vapor, oil-water separation and recovery take place. After separating the entrained liquid from the vapor, the stream is fed to the flare unit, where it automatically ignites and burns in the atmosphere. Detailed design of a flare knock-out drum can be seen in Section 5.4. In summary, a typical closed pressure release and flare system includes relief valves and discharge lines from process units, knock-out (KO) drums to separate vapors and liquids, gas seals for flashback protection, and a flare and igniter system. Steam may be injected into the flare tip to reduce visible smoke.

1.6.9 Workshop and Lay-down Area Chemical plants commonly have a workshop or maintenance facility for equipment repairs, parts fabrication or for keeping maintenance equipment and tools. Dedicated technicians and workshop manager are assigned to work in this unit. Also, during plant upgrade, the workshop serves as a prefabrication space. The lay-down area is a floor or ground area for laying down components during maintenance. Process units consisting of large equipment are commonly located in outer areas in the complex site so that sufficient spaces can be available for their dismantling and installation. This equipment is first kept in a lay-down area before being erected at the required position. Lay-down areas are usually large enough to contain mobile cranes of various sizes and capacities, low-bed trucks, and so on.

1.6.10

Office Building and Others

Office buildings are also commonly found in a chemical plant. Plant senior management, engineers, administrators and others work in office buildings. These buildings are usually noiseproof and fireproof due to the potential noise and fire hazard associated with a typical chemical plant. Other buildings also exist in a chemical plant such as a clinic, library in some cases, kitchen and mess, etc. These buildings are usually out away from process areas.

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Figure 1.6.13 Engineering Office Meeting Room.

Figure 1.6.14 Engineering Design Office.

1.6.11

Warehouse and Storage

Chemical plant feedstocks and products are kept in the storage facility. Also, procured parts and equipment are stored in the storage area.

1.6.12

Firefighting Unit

Due to the risk of fire in a typical process plant, a firefighting unit is usually located in chemical or process plants. Men and women firefighters work in this area. Firefighting vehicles and other fire water reservoir are also located here, especially in gas processing plants.

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1.6.13

Water Generation Unit

Large chemical process plants will commonly have a water generation unit that will supply the water needed for steam production or process cooling, portable water for workers, sanitary water, water for humidification, laboratory experiments, and so on.

1.6.14

Waste Treatment and Disposal Unit

A section of typical chemical plant is usually designed for waste collection and treatment. Every chemical plant generates waste or unwanted products. This makes this unit a very important one. The waste receiving and treatment unit is a mini chemical process plant. In order to treat effluent and solid wastes, several unit operations are required. In this era of quest for sustainability, waste treatment is imperative. This is coupled with increasing pressure from environmental regulatory bodies. Recovered waste products also add value to the overall benefit of a process plant. Again, to balance the ecosystem, some wastes are simply treated and re-introduced into the ecosystem. In some process plants, the wastes are channeled to another location where a waste treatment plant is constructed. The waste can be transported via pipeline, by road or sea to this location. Figure 1.6.15 shows an effluent waste treatment plant recently constructed and commissioned at the out skirt of Port Harcourt, close to the sea. The plant receives effluent waste disposal from many oil facilities, processes and recovers useful products. The effluent wastes are transported by sea to this location. Recovered products include a very high-quality oil known as heavy oil, marine fuel or furnace oil, which is in high demand globally. The oil is burned in a furnace or boiler for the generation of industrial process heat or used in an engine for the generation of power.

Figure 1.6.15 Effluent waste disposal Plant recently Commissioned in Port Harcourt.

2 Chemical Engineering Basic Education and Training 2.1 Introduction Chemical engineering education begins with a specific interest in mathematics and physics combined with an aptitude for chemistry. Chemical engineering covers a wide range of topics but a basic education in the field starts with a firm foundation in mathematics, physics and chemistry (including introductory chemistry courses, and advanced courses such as organic and inorganic chemistry). As students progress through the curriculum, they learn more fundamental engineering science. To become a chemical engineer, the prospective candidate will undergo two stages of development: (1) college or university education and (2) on-the-job training. This chapter explains the college or university chemical engineering education models, the fundamental courses and the core subjects undertaken and the academic transition from science to engineering. The core subjects are discussed in detail and attempt is made to qualitatively explain how these subjects are being applied in real-world chemical engineering. Finally, the second phase, which is on-the-job training for new chemical engineering hires, is discussed. Details of the career progression from college or university to professional engineering career is explained, including job roles of new chemical engineering hires, required working tools, prospects, challenges, specific professional training and critical career success factors. Also, there is discussion on the necessary background preparation the new hire requires in order to support and register as a professional engineer.

2.2 Chemical Engineering Education Model The chemical engineering education model, in terms of composition, content and duration, is still a matter of global debate. While the overall Uche Nnaji (ed.) Introduction to Chemical Engineering: For Chemical Engineers and Students, (37–78) © 2019 Scrivener Publishing LLC

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content may slightly vary, course structure and duration clearly vary across the world. In some universities or countries, a first degree (BEng) in chemical engineering is awarded after three or four years of undergraduate studies while in other countries the curriculum may last for five years. However, this variation in course duration is not peculiar to the chemical engineering discipline. EU member countries in 1999 introduced a twostage education system known as the Bologna model process for undergraduate education. This involves a three-year undergraduate study and a two-year master’s cycle (MEng). Progression to the master’s cycle will depend on satisfactory performance in the bachelor’s cycle. Generally, a Bachelor of Engineering degree in chemical engineering (BEng) lasts from three to four to five years. A Master of Engineering (MEng) lasts from one to two years. A five-year undergraduate study model is here succinctly described. The first and second year serve as the foundation for the five years of “engineering sciences” or “analysis”. The first year involves study of science subjects—physics, basic mathematics and chemistry. The second year is devoted primarily to the basics of all engineering fields, including calculus (engineering mathematics) and advanced chemistry. Chemical engineering curricula tend to begin specializing in the student’s third year, where students begin to apply scientific principles to technological problems. During the third year and first semester of the fourth year, students are exposed to rudiments of the core chemical engineering subjects. Core chemical engineering subjects include engineering thermodynamics, separation techniques, heat and mass transfer, unit operations, chemical reaction engineering, process dynamics and control, chemical engineering laboratory, process modeling and computation, and plant design. The second semester of students’ fourth year is devoted to industrial attachment, where students are expected to acquire some practical industrial experience by going to work in an engineering-related industry for six months. During the fifth year, students are required to prepare a conceptual design of a process or large part of a process. At this stage, students draw upon various aspects of their previous engineering science and design knowledge to address a meaningful design problem. This involves flow sheeting, mass and energy balances, equipment sizing, costing and financial analysis, computer simulation, as well as detailed design of at least one piece of process equipment. Students are also expected to choose a site (can be dummy), prepare a plant layout, carry out health and safety analysis and perform an environmental impact assessment of the project.

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Figure 2.2.1 Chemical Engineering Undergraduate Student (Picture Sourced at: http:// www.swansea.ac.uk/engineering/chemical/, 2014).

2.3 Objectives of Chemical Engineering Education Chemical engineering education is aimed at producing graduates who can: • Demonstrate the ability to apply mathematics, computer skills, engineering principles, and natural sciences to chemical engineering practice. • Combine principles and techniques from engineering, mathematics, engineering planning and project management, and the natural and social sciences to analyze, develop and evaluate alternative design solutions to engineering problems with specific constraints. • Draw upon the basic knowledge, skills, and tools of chemical engineering curriculum to develop system-based engineering solutions that satisfy constraints imposed by a global society. • Improve their skills through further formal education and training, independent inquiry, and professional development. • Work independently as well as in collaboration with others, and demonstrate creativity, leadership and accountability, ethical and social responsibility. • Demonstrate preparedness for entry into careers in chemical engineering in the diverse areas including mining, petrochemical and petroleum refining, bioengineering,

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Introduction to Chemical Engineering semiconductor manufacturing, pharmaceutical and food processing, etc. • Demonstrate readiness to pursue graduate education and research in chemical engineering at major research universities. • Demonstrate ability to work effectively, communicate well, and be aware of the necessity for personal and professional growth.

Due to the broad nature of chemical engineering, the chemical engineering curriculum is ever-evolving worldwide. Furthermore, the requirements made of graduates by the classical industries (the chemical, pharmaceutical and petrochemical industries) are changing in proportion to the extent to which chemical engineers are finding employment outside the classical industries such as in aerospace, biomedical, nanotechnology and others.

2.4 Academic Shift from Science to Engineering Chemical engineering education is structured such that students can gradually transition from science to engineering knowledge. The education, as explained earlier, begins with study of basic sciences and then basic engineering sciences, to the actual application of the basic science subjects and engineering methodology, to solve real-life problems or make possible a part or a whole system or process that will either solve human needs and problems or produce useful products for humans.

Design is a common activity to all engineering discipline. The goal of chemical engineering education is achieved by the introduction of a design course to them. This usually includes the following: • Incorporation of sciences and theories into a design. • Development of student’s inventiveness. • Use of a design procedure and consideration of alternative solutions. • Introduction of practical tools and software used in an engineering office. • Exposure to the art of dealing with uncertainties. • Completion of an entire process study.

Chemical Engineering Basic Education and Training 41 Basic Sciences General Chemistry General Physics Mathematics

Organic Chemistry Physical Chemistry Inorganic Chemistry Biochemistry

General Engineering

Chemical Engineering Core

Chemistry Core

Chemical Engineering Analysis Process Modeling and Computation Chemical Engineering Thermodynamics Fluid Mechanics Transport Phenomena (Heat and Mass Transfer) Chemical Reaction Engineering Chemical Process Dynamics and Control Separation Processes Computer-Aided Design

Design Core Process Engineering Lab. Chemical Process Design and Evaluation Chemical Plant Design and Economics

Chemical Engineering Lab. Core Chemical Engineering Laboratory

Engineering Mathematics Computer Programming Instrumentation Laboratory Probability and Statistics

Electives/Area of Specialization Biochemical Engineering/Biotechnology Microelectronic Device Environmental Engineering Engineering Mechanics Engineering Science Material Science and Engineering Nanotechnology Thermal Engineering and Systems Pulp and Paper Technology Polymer Technology Coal utilization and Processing Technology Petroleum refining and Processing Engineering Management

Figure 2.4.1 Structure of Chemical Engineering Curriculum.

Design project plays a very crucial role in providing students with design experience. Chemical engineering students, through this design exposure develop and improve technical skills as well as soft skills required to become professional engineers. After the design training they are better suited to meet the needs of industry. In chemical engineering, design usually refers to design of equipment or design of all or the major part of a chemical processing plant with safety, environmental and economic consideration. Chemical engineers depend on sciences, engineering methods, experience and ingenuity to develop processes and equipment necessary for economical production of useful products. Design processes usually involve almost all the core chemical engineering courses as explained in the introductory section. At this stage,

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Chemical Reaction Engineering

Process and Equipment Design

Chemical Engineering Plant Design

Chemical Engineering Thermodynamics Fluid Mechanics

Chemical Engineering

Chemical Engineering Separations

Heat and Mass Balance

Process Dynamics and Control

Figure 2.4.2 Chemical Engineering Core Subjects.

students will be in the trade of integrating sciences and engineering sciences in solving real-world problems. This is where the definition of engineering as an application of sciences comes in. This is usually the climax of chemical engineering education—a very interesting experience! Design courses are typically more demanding than other courses for both department and students but impact on student experience is certainly worth the extra effort. During the design project students are instructed to: • Understand the chemistry of the process; • Analyze background information about the process, its implementation, current market, safety and environmental issues, etc.; • Produce with the aid of a computer, a complete process flow diagram of the process; • Select and size pressure vessels, pipes and valves, pumps, blowers, heat exchangers, compressors, boilers, etc.; • Carry out complete heat and mass balances on the process using appropriate process engineering design software such as HYSYS and PRO II; • Perform a detailed design of the main equipment of the process stating and justifying any assumptions made and

Chemical Engineering Basic Education and Training 43

• • • • •

referring to appropriate standards (might include sizing of pump and pipes); Establish a process control philosophy; Carry out a detailed economic analysis of the project; Produce a complete P&ID in some projects; Choose a site and prepare a plant layout; Prepare a complete design report.

Equipment design is a key part of design process. This involves selection, sizing, specification, and design of each unit operation of the process so that the equipment will perform the required function. Chemical engineering design projects with broader focus are intended to be done through group interaction and results and information sharing. However, each student will be required to defend the project. As a result, students have no choice but to get seriously involved in the design process from the onset. Some design project topics are: • Design of a chemical plant that produces 2.5*105 metric tons per annum of 4-hydroxy-2-butanone by dehydrogenation of 2, 4-hydroxy butanol (chemical). • Design of a water treatment facility to provide a pulp and paper plant with 18,000 m3/h of water using a nearby river as a source (Pulp & Paper). • Design of a newsprint producing complex: 46% of pulp produced at the thermo-mechanical pulping (TMP) department is combined to 58% of pulp coming from the new De-ink Plant (DIP) department to produce 320,000 machine dry Tons/year at the new paper machine department (Pulp & Paper). • Design of a chemical plant to produce 16 million lbs/year of detergent using ethylene oxide and lauryl alcohol (Chemical). • Design of a soya milk production plant and upgrade of a beer plant (Food). • Design of a hydrochloric acid regeneration plant implemented in a metal leaching plant to regenerate pure acid at a rate of 162,000 Tons/year: Comparison of two processes – pyrohydrolysis (thermal spray roasting technique) and gypsum precipitation (Metallurgical). • Design of an Industrial fumed silica production plant with nominal capacity of 2,500 Tons/year: Comparison of two technologies – Flame hydrolysis and thermal plasma (Metallurgical).

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Figure 2.4.3 A food plant (Image sourced at: http://www.processengr.com/markets/foods_ beverages.html, 2016).

2.5 Chemical Engineering Core Subjects and Applications This section explains core chemical engineering courses and how they are being applied in the industry. Chemical engineering core courses include fluid mechanics, transport phenomena, chemical engineering thermodynamics, chemical reaction engineering, separation techniques, chemical engineering laboratory, plant design and economics, and process dynamics and control.

2.5.1 Chemical Reaction Engineering Chemical reaction engineering deals with the exploitation of chemical reactions on a commercial scale. The main objective is the successful design and operation of chemical reactors. Reactors are an essential part of many chemical process operations. Sound reactor design is essential for maximizing reaction rates and optimizing product throughput rates. Hence, the study of chemical reaction engineering emphasizes qualitative arguments, simple design methods, graphical procedures and comparison of capabilities of the major reactors. It deals with chemical identity, general mole balance equation, reaction rate, and mole balance on different reactor types, design equations, conversion, flowrates and reactor sizing. Chemical reaction engineering also deals with chemically reactive systems of engineering significance. It is the discipline that quantifies the interactions of transport phenomena and reaction kinetics in relating reactor performance to operating conditions and feed variables (Source: chemeng.queensu website). Transport phenomenon is explained in sub-section 2.5.3.

Chemical Engineering Basic Education and Training 45 An industrial chemical reactor is a complex device in which heat transfer, mass transfer, diffusion, and friction may occur along with chemical reaction, and it must be safe and controllable. Additional details on chemical reactor are found in Perry’s Chemical Engineers Handbook, McGrawHill, 1999, section 23 [30]. Chemical reaction engineers construct models for reactor analysis and design using laboratory data and physical parameters, such as chemical thermodynamics, to solve problems, select operating parameters and predict reactor performance.

From an engineering point of view, reaction kinetics has these principal functions: • • • • •

Establishing the chemical mechanism of a reaction Obtaining experimental rate data Correlating rate data by equations or other means Designing suitable reactors Specifying operating conditions, control methods, and auxiliary equipment to meet the technological and economic needs of the reaction process

Chemical reaction engineering and engineering chemistry is perhaps the discipline that differentiates chemical engineering from other fields of engineering.

2.5.1.1 Applications of Reaction Engineering The knowledge acquired in this course is required in industrial catalysis and design of manufacturing processes. Chemical reaction engineering is required in the development of novel and the improvement of existing technologies: • Chemical kinetics and chemical reactor design; • Discover routes to make a product from different feedstock (New processes for synthesis-gas production; Hydrocarbon production from synthesis gas; polymers produced from renewable feedstocks; Biodiesel production); • Reduce/eliminate unwanted intermediates, solvents, byproducts and so on (Reduced solvent content in paints; NOx reduction);

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Introduction to Chemical Engineering • Find alternative processes to replace old ones (use of metallocene catalysts to produce new HDPE/PP materials); • Ethylene production (ethylene is used for manufacturing polyethylene which is the world’s most broadly used plastic); • Environmental pollution modeling (Allows us to evaluate, estimate or determine the trend of gaseous pollution formation); • Pharmacokinetics (CRE can be applied to describe human body-drug interaction).

2.5.1.2 The Chemical Reactor The engineering of chemical reactions is required in chemical kinetics and chemical reactor design. Chemical reactor design is the main application of chemical reaction engineering. Reactor design is adjudged the most distinguishing factor between chemical engineers and other engineers. Reactor unit is the heart of any chemical process and is the main unit that determines a plant’s yield and efficiency. Chemical engineers consequently continuously target maximum net present value for a given reaction. Reactor design involves reactant(s), material transfer, thermodynamics, reaction kinetics, and product(s). Chemically reacting flows or streams are those in which the chemical composition, properties and temperatures change as the result of a simple or complex chain of reactions in the fluid. Hence, reactors are said to be complex because temperature is not uniform and/or constant; multiple reactions almost constantly occur; flow patterns are complex; many reactors involve multiple phases; reaction mechanisms and reaction kinetics are never clearly known and feedstock quality and product specifications often change. Reactor design involves multiple aspects of chemical engineering. Chemical engineers utilize their knowledge of chemistry, chemical equations, economics, further mathematics, physics, biology (for bioreactors), catalysis, chemical kinetics, thermodynamics, fluid mechanics, heat and mass transfer, mechanical engineering, engineering management, safety engineering and the environment, and other process equipment. Chemical throughput from a continuous flow reactor usually determines the capacity, type and rating of corresponding secondary process units and other primary units—proprietary and non-proprietary process equipment, to be installed in a plant.

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Figure 2.5.1 A chemical reactor (Image Sourced at: http://www.koreaittimes.com/image/ hnatech, 2016).

To achieve optimum solution during reactor design, the maximum net present value or lower cost reactor may not be the only factors to consider. Overall additional cost of the treatment of materials leaving the unit in terms of the required type and specifications of treatment equipment, are to be considered. The overall process plant economics must be considered for any given reactor design alternative.

Figure 2.5.2 A continuous stirred tank reactor (CSTR) (Image sourced at: https://en.wiki pedia.org/wiki/Chemical_reactor#/media/File:Chemical_reactor_CSTR_AISI_316.JPG, 2017).

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Batch Reactor A batch reactor is a pressure vessel designed to contain a given quantities of reactants (feedstock) over a given period. A typical batch reactor consists of a pressure vessel or tank with agitator and integral heating/cooling system, and these vessels may vary in size from less than 1 litre to more than 15,000 litres. The top is designed to receive the feedstocks and the discharge through bottom outlet. While vapors and gases discharge through connections in the top, liquids are usually discharged out of the bottom. Batch reactor has its own advantage over continuous reactor. Batch reactor is a versatile single vessel that can perform a sequence of different operations without the need to break containment, which is particularly useful when processing toxic compounds. Continuous Reactor Continuous reactors are pressure vessels or pipes that allow reactions to be performed as a continual process rather than like batch. Reactants (feedstocks) are continually added to the input of the reactor and product continually collected from the output. The reactor can be manufactured from a variety of materials including stainless steel, glass and polymers and is typically tube-like. Diffusion and static mixers are mixing methods applied. There are advantages of using continuous flow reactors in a chemical plant. Continuous flow reactors allow firm control over reaction conditions including heat transfer, time and mixing and the residence time of the reagents in the reactor is calculated from the volume of the reactor and the flow rate through it. Thus, flow rates of reagents can be controlled for achieving a longer or shorter residence time. Commercial Application Specifically, examples of industrial and or commercial reactors include: fluid catalytic cracking (FCC) unit of a petroleum refinery, blast furnaces for iron making, activated sludge ponds for sewage treatment, polymerization tanks for plastic mixing, mixing vessels for paint manufacture, pharmaceutical vessels for drugs manufacture, rocket engine fuel combination chamber, coal burning electrical power station (fluidized bed combustors), automobile catalytic converter (following an engine) and so on. However, unarguably most petrochemical reactors account for most of the industrial chemical production in the world, with very high volume. Examples include ammonia, sulfuric acid, reformate  (benzene, toluene, ethylbenzene and xylene) and alkylate produced from the alkyl unit of a petroleum refining (gasoline blending stock).

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2.5.2 Thermodynamics for Chemical Engineers One of the more challenging subjects for engineering undergraduates is thermodynamics. The perception by most chemical engineering students is that the course is a difficult one. More worrisome is the fact that the thermodynamics course usually lasts longer than other subjects taught in undergraduate chemical engineering. In addition, the abstract nature of the course as it is being presented in most universities complicates the problem. There are hardly any chemical engineering thermodynamics textbooks that describe any industrial application of the subject other than applications in steam engine and gas turbine. Students’ perception is that steam technology is obsolete, and this increases students’ indifference to the course. However, fundamental thermodynamic principles arise in so many areas of chemical engineering that a sound background in thermodynamics is of huge value to the undergraduate student.

Figure 2.5.3 A Nuclear Reactor (Image Sourced at: http://engineersacademy.net/img/ Thermodynamics.jpg, 2016).

Thermodynamics as a discipline is the science of heat and the laws that govern the transformation of heat into other forms of energy. The science of thermodynamics was born, in part, from a craving to comprehend and improve the earliest steam engines. Thermodynamics is one of three disciplines collectively known as the thermal-fluid sciences, or sometimes, just the thermal sciences: thermodynamics, fluid dynamics and heat transfer. Thermodynamics can also be said to be the branch of science that represents the principles of energy transformation in macroscopic systems. The general boundaries which practitioners experience has shown to apply to all such transformations are known as the laws of thermodynamics. This

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can also be defined as the study of conversion of energy into heat and work and its connection with temperatures, pressure and volume. The various elements of study in thermodynamics include Entropy (S), Heat (H), Work (W), Pressure (P), Volume (V), Temperature (T), Internal energy (U/E), Specific heat (C/c), Universal gas constant (G), and Gibbs free energy (G). The basic thermodynamic properties that arise with regard to the first and second laws of thermodynamics are entropy (S) and internal energy (U/E). These properties, together with the two laws for which they are vital, apply to all types of systems. On the other hand, different types of systems are characterized by different sets of measurable coordinates or variables, for example, Temperature (T), Pressure (P), and Composition. The type of system most generally faced in chemical technology is one for which the primary characteristic variables are Temperature (T), Pressure (P), Molar volume (V), and Composition, not all of which are necessarily independent. Such systems are called PVT systems and are typically made up of fluids which can be liquid or vapor. The first course of the thermodynamics undergraduate curriculum generally focuses on the application of energy, mass and entropy balances to chemical and engineering processes. The second course generally involves an examination of non-ideal behavior—both for pure components and for mixtures, as well as phase and chemical equilibria. However, these courses are often entrenched in theory and provide limited exposure to the specific applications in unit operations and in industry where these non-ideal properties are substantial. Providing the student with real-world examples and applications of thermodynamic principles can help them to better integrate their understanding of thermodynamics with other chemical engineering subjects that apply thermodynamics and affords them the capacity to draw on this understanding to explore and make more contributions to the field.

2.5.2.1 Applications of Thermodynamics Typically, thermodynamics is an essential requirement to a course in heat transfer, as the laws of thermodynamics are essential in understanding the mechanism of heat transfer. Hence, it is said that the amount of heat transferred in a thermodynamic process which changes the state of a system depends on how that process occurs, not only the net difference between the initial and final conditions of the process. It is important to note also that chemical reaction engineers construct models for reactor analysis and design using laboratory data and physical parameters, such as chemical thermodynamics, to solve problems and

Chemical Engineering Basic Education and Training 51 predict reactor performance (http://en.wikipedia.org/wiki/Chemical_engi neering, 2014). Also, thermodynamic properties and equations play a major role in separation processes, particularly with respect to energy requirements, phase equilibria, and sizing equipment. Thermodynamics can explain equilibria. Hence, this approach permits the extrapolation of data to new compositions and predictions from the behavior of chemically similar systems. This can be used to prevent azeotropic solvent swaps ending where they started and to better comprehend a number of other operations dependent on phase equilibria. In addition, reliable thermodynamic data are indispensable for the accurate design or analysis of distillation columns used in petroleum refineries, chemical processing plants and so on. Failure of equipment to perform at specified levels is frequently attributable, at least in part, to inadequacy of such data. Furthermore, steady-state and steady-flow processes which are predominant in chemical technology are generally subjected to thermodynamic analysis. The purpose of the analysis is to determine the efficiency of energy use or production and to show how energy loss is dispensed among the steps of a process. Another example of thermodynamic application is found in heat recovery steam generator (HRSG) design—condenser, turbine, pumps, boiler designs, and so on. Spark-ignition reciprocating engines and jet engines also work on the principles of thermodynamics. Generally, in the industry, chemical engineering thermodynamic is applied in the design, testing, and development of products that require constraints on pressure, temperature, and volume. In aviation industries thermodynamic principles are applied in the design and construction of rocket systems. In the environment and power sector, air pollution control, thermal processing, and power equipment companies such as coalfired power industries and atomic energy plants apply thermodynamic engineering principles in the design and testing of incinerators, scrubbers, filters, kilns, dryers, furnaces, and boilers. Other thermodynamic engineering industrial applications include design and construction of test fixtures, such as environmental chambers with ovens and refrigerators for testing the heat tolerance of materials, and thermocouples for readout and feedback of changing test temperatures. Moreover, the green revolution that encourages alternative and clean energy sources, such as passive solar, active solar, water, wind and electricity, require thermodynamic engineering skills to calculate energy balances in exchange systems for cooling, heating and running electrical grids

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Figure 2.5.4 Chemical process plant where thermodynamic principles are applied (Image Sourced at: http://www.ensepatec.com/en/products/horizontal-separators/horizontal-kodrum.html, 2014).

for both homes and industry. Also, chemical thermodynamic engineering takes account of systems that experience change of state in areas as diverse as steelmaking and also the production of nano-sized particles in the design of smart materials. In conclusion, chemical engineering thermodynamics can be applied in other chemical engineering courses and also in the industry, as explained above.

2.5.3 Transport Phenomena (Transport Processes) Transport phenomena is an advanced core chemical engineering course focusing profoundly on mathematical interpretations of the principles of heat and mass transfer, steady and transient conduction and diffusion, and radiative heat transfer. They are the physical processes that involve molecular and convective transport and include both fluid flow and separation operations. Basic equations for describing three transport phenomena— fluid mechanics, heat and mass transfer—in the macroscopic, microscopic and molecular levels are similar. This course also covers fundamental concepts of diffusion and conservation within momentum. Essentially random motion of molecules results in a net transfer of mass from an area of high concentration to an area of low concentration and these driving forces also result in mass transfer from high to low concentration. Hence, the amount of mass transfer can be quantified through calculations and application of mass transfer co-efficient. Transport phenomena of complex fluids such as macromolecular and molecular dynamics exist. Macromolecular dynamics refers to the

Chemical Engineering Basic Education and Training 53 non-equilibrium behavior of large clusters of molecules or macromolecules, such as polymers, proteins, colloids, aerosols and so on. Examples of macromolecular non-equilibrium phenomena include the flow of polymeric solutions, the folding and diffusion of proteins, electrophoretic motion of DNA and aerosol and colloid transport phenomena, to name just a few. Molecular dynamics includes the study of the transfer of material or properties at the molecular level and, hence, it is also a smaller-scale or refined view of macromolecular dynamics. Chemical engineer E.N. Lightfoot published Transport Phenomena in Living Systems, which was the first book to combine the topics of biomedicine and transport phenomena.

Figure 2.5.5 Fluid transport system (Image Sourced at: http://www.aiche.org/academy/ webinars/transport-phenomena-heat-transfer, 2016).

Transport properties in transport phenomenon include: surface area of heat transfer (A), surface temperature (Ts), temperature of the fluid at bulk temperature (Tb), heat transfer coefficient (h), the mass transfer coefficient (kc), temperature of object’s surface (To), temperature of environment (Tenv), the mass transfer rate (dn/dt), the effective mass transfer area (A), the driving force concentration difference (ΔCA), viscosity (μ) and density (ρ).

2.5.3.1 Applications of Transport Phenomenon Transport phenomenon is applied in solving engineering problems in flow in porous beds, fluidized beds, mixing and stirring, and so on. Knowledge of heat transport and momentum transport (fluid flow) is required to design a heat exchanger and other static process equipment, including distillation

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columns. Heat exchangers, for example, are used throughout chemical engineering processes to transfer heat energy from one stream to another. Heat exchangers are broadly used in the manufacture of electronic and optoelectronic devices, such as CPUs, higher-power lasers, and light emitting diodes (LEDs). Other applications include space heating, refrigeration, air conditioning, power generation and chemical processing. Heat exchangers used in air conditioning and refrigeration systems and the radiator in a car, are some examples of heat sink. Other areas of application of heat transfer include insulation and radiant barriers, radiative cooling, magnetic cooling, laser cooling, evaporative cooling, thermal energy storage and others.

Figure 2.5.6 Silicon Carbide Shell and Tube Heat Exchanger – ideal for corrosive media (Image sourced at: http://www.mycheme.com/, 2013).

Similarly, knowledge of mass transport is required to design other main chemical engineering processes, such as design of processes and equipment including liquid-liquid extraction column, evaporator systems, driers, membrane devices, binary distillation systems, gas absorbers and cooling towers. Knowledge of transport phenomena can be applied in the environment to model the transport of nutrients, sediments, and pollutants in the aquatic environment. These models can be used to predict algal blooms, suggest sources of nutrient or pollutant plumes, determine the feasibility of waterfront construction, or help determine pollution containment and cleanup plans. Chemical engineers applied mass transfer phenomena, complex flow problems solving techniques through use of Newtonian fluid-mechanics analysis, sophisticated mathematical models, process control technologies that maximize chemical reaction rates and reaction yields, and so on, in developing artificial organs, such as, kidney dialysis machines and lung oxygenation units. This is further explained in Chapter 3. Further explanation

Chemical Engineering Basic Education and Training 55 is given to the application of fluid mechanics, heat and mass transfer in the electronics sector to maintain a level of cleanliness usually required in the process of designing clean rooms. It is also applied in micro-deposition process for use in wafer and semiconductor manufacturing. Furthermore, liquid metals at high enough temperatures behave as Newtonian liquids, hence micro drops of liquid metals are being printed on a substrate (the material on which a process is conducted). This is applied in the design of tiny electronic circuits used in making smart mobile phones, computers, among numerous others. Transport phenomenon is applied in the design of chemical valves, prostheses, drug delivery systems and others. These systems are designed with intelligent gels. Flexible macromolecules in gels expand or contract subject to the interactions with the surrounding solvent molecules or in response to external stimuli. Another area of industrial application of transport phenomenon is in the development of a penetrating warhead filled with an advanced thermobaric explosive that when detonated can produce sustained blast pressures within a target. Chemical engineers also apply transport phenomena to improve the design and forecast of fluid flow around or inside structures or objects of random shapes using the computational fluid dynamics (CFD).

2.5.4 Separation Processes Separation technique is a very important discipline to chemical engineers. Crude oil well products for example, more often constitute a combination of gas, oil, water and various contaminants which must be separated and processed. Demand is greater for the purified various hydrocarbons such as natural gases, liquefied petroleum gases, gasoline, diesel, kerosene, jet fuel, lubricating oils, asphalt and so on. In chemical engineering separation process or technique is a method to achieve any mass transfer phenomenon that converts a mixture of substances (solids, liquids or gases) into two or more separate products or product mixtures or fractions, at least one of which is enriched in one or more of the mixture’s constituents. The separated products could be different in the chemical properties or some physical property such as size, texture, color or crystal modification or other separation into different components. For liquids, the mixtures to be separated can be miscible (forming a homogeneous mixture when mixed together) or immiscible (not forming a homogeneous mixture when mixed together). Various forms of separation exist. Chemists have discovered several laboratory means of separating mixtures using beakers, test tubes, graduated cylinders, funnels, flasks and others, by manual

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means. Automated laboratory separation equipment or mini (pilot) plant separators also exist. However, separating mixtures of solids, liquids or gases in commercial plants is very complex and requires complex engineering analysis and design. Sometimes multiple separation techniques are arranged in a plant and process streams can undergo a series of separations until the desired separation is achieved. Sometimes liquid mixtures can form azeotropes, a situation where two liquids which have a constant boiling point and composition are encountered throughout distillation separation. In this case an extractive distillation process will be applied. Hence, a solvent that forms no azeotrope with the other component will be introduced. It is broadly applied in the chemical and petrochemical industries for separating azeotropic, close-boiling, and other low relative volatility mixture. Separation can be done on a batch or continuous process but this is usually a continuous process in a chemical plant. Chemical engineering undergraduate students are taught various separation techniques applied in the industry. Among them are liquid-liquid extraction, supercritical fluid extraction, adsorption, chromatography, filtration, thermal diffusion, crystallization, magnetic field separation, membrane separation processes, foam separation, bio-separation, distillation, flashing, stripping and gravitational separation. They are required to work from the laboratories, like their chemistry student counterparts, using laboratory equipment. Subsequently, the engineering undergraduates will be taught how to size/design commercial separators and separation processes. Students are also taught how to use a computer simulation method to size a separator or model a separation process. The separation process is an example of a unit operation in chemical engineering. The classification can be based on means of separation, mechanical or chemical.

Figure 2.5.7 A LP Horizontal Separator.

Chemical Engineering Basic Education and Training 57 Depending on raw mixture, various processes can be used to separate mixtures. Many times, two or more of these processes have to be used in combination to obtain the anticipated separation and in addition to chemical processes; mechanical processes can also be applied where possible.

2.5.4.1 Applications of Separation Processes Industrial application of separation techniques is presumably more understandable to students than other taught courses. As explained above, separation is indispensable in chemical process plants. Streams of feedstocks can be designed to undergo specific separation before being fed to the reactor. Output of the reactor which may contain unwanted products, will require further separation. The waste or unwanted products will require treatment (or purification) and separation before discharge to the atmosphere or the surrounding environment. Now let us briefly explain the industrial applications of some of the various types of separation processes studied in chemical engineering. The method of separation which allows separation of distillates from less volatile substances is called distillation. Vacuum distillation and extractive distillation are some types of distillation separation. Vacuum distillation columns normally used in oil refineries have diameters ranging up to about 15 meters, heights ranging up to about 55 meters, and feed rates ranging up to about 170,000 barrels per day.

Figure 2.5.8 Sulfate Removal System (Credit: Schlumberger).

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A platform (fixed-bed adsorption operation) where a column filled with chromatographic packing materials is fed with mixture of components to be separated is called chromatography. Chromatographic separation is widely applied in biochemical industry, protein affinity chromatography for example, can be used for the separation of individual compound, or a group of structurally similar compounds from crude-reaction mixtures and fermentation broths by exploiting very specific and well-defined molecular interactions between the protein and affinity groups immobilized on the packing-support material. Examples of affinity interactions include antibody-antigen, hormone-receptor, enzyme-substrate/analog/ inhibitor, metal ion-ligand, etc. Gas chromatography (GC) type is broadly used in petrochemical, environmental monitoring, and industrial chemical fields. Note that because separation of biological processes must be done at or near ambient temperature to avoid product denaturation, distillation cannot be used. Other applications of Chromatography include water purification, food and beverage production (example, fructose syrup), and petrochemical production (example, xylene). Magnetic Field Separation is the separation of minerals based on their magnetic tendency. This is used in the industry to improve product purity, for example, Eriez has developed a range of rare earth (RE) drum separators which feature Erium 3000, a high- quality rare earth permanent magnetic power source. These separators are able to purify large quantities of materials such as foods, plastics, abrasives, metal powders, ceramics material, paper, glass cullet, soda ash, kaolin clay, chemicals, gypsum and quartz powder. They take away very fine ferrous particles, locked particles and strongly paramagnetic particles to improve product purity and safeguard processing equipment such as crushers, mills and grinders, that don’t react well to metal in the product. These separators are in use in many manufacturing industries because they can be very cost effective, efficient and more environmentally friendly than alternatives. Furthermore, separation of liquids and gases are usually done using membrane separation methods. Membrane technology is an application for reducing energy use in separations. The technology includes dialysis, ultra-filtration and reverse osmosis. Also, there are hybrid and more interesting membrane separation methods that are known to be effective. They include helium separation through glass, electro dialysis, hydrogen separation through palladium and alloy membrane, liquid-surfactant and immobilized membranes. For instance, if a plant is processing at full capacity but wants to boost production further, the use of membrane to remove water from fluid to pre-concentrate the liquids or solids, ahead of the evaporator debottlenecking will be effective. Another example, in the Middle East, on

Chemical Engineering Basic Education and Training 59 islands, and in certain coastal areas, thousands of tons of drinking water are produced every day by passing pressurized seawater across a very thin membrane that permeates water with practically none of the dissolved salts; also, tons of water are purified to an exquisite degree for use in making microchips, most of the purifications having been accomplished by passing the water through membranes; and furthermore, huge quantities of nitrogen are purified from air by membranes operating from the output of a simple, single state air compressor. See schematic of pressure-driven driven processes in Figure 2.5.9 below [30].

Feed

High Pressure Permeate

Concentrate or Retentate (Matter retained through a semipermeable membrane) Residue

Membrane

Figure 2.5.9 Schematic of pressure-driven processes.

Another separation technique is foam separation, which is divided into two, namely, foam fractionation and froth flotation. Per Wikipedia, foam fractionation is a chemical process in which hydrophobic molecules are preferentially separated from a liquid solution using rising columns of foam. Hydrophobic molecules are molecules that have no attraction with water molecules such as molecules of alkanes, oils, fats, and greasy substances in general. Foam fractionation is commonly used, albeit on a small scale, for the removal of organic waste from aquariums; these units are known as “protein skimmers”. A protein skimmer or foam fractionator is a device used to remove organic compounds such as food and waste particles from water. It is most commonly used in industrial applications like municipal water treatment facilities and public aquariums. Smaller protein skimmers are also used for filtration of home saltwater aquariums. Conversely, it has much broader application in the chemical process industry and can be used for the removal of surface-active contaminants from wastewater streams in addition to the enrichment of bio-products [31]. Froth flotation separation is a process for selectively separating the hydrophobic materials from the hydrophilic. A hydrophile as defined in Wikipedia is a molecule or other molecular entity that is attracted to, and tends to be dissolved, by water. It usually implies the removal of solid

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particulate material example, ore flotation. This is used in various processing industries such as minerals refining in mining industry. Crystallization process is another very important separation technique. It is a naturally occurring process which has been engineered and amply applied in the industry. Crystallization can occur from a solution, from the melt or through deposition of material from the vapor phase (desublimation). This type of separation thus is accomplished by producing crystals from a solution through deliberate adjustment of the solution in order to make it supersaturated so that excess solute can crystallize in pure form. By lowering the temperature or by concentration of the solution, in each case to form the supersaturated solution, crystallization can occur. It is a separation process in which mass is transferred from a liquid solution in the form of crystals. Once supersaturation is reached, the solid-liquid system gets to an equilibrium stage and crystallization is completed, unless the operating conditions are modified from the equilibrium position so as to supersaturate the solution again. Crystallization is applied at some stage in virtually all process industries as a method of production, purification or recovery of solid materials. Crystallization separation methods are also widely applied in the pharmaceutical processing industries as purification and separation process for the isolation and synthesis of pure active pharmaceutical ingredients (API), controlled release pulmonary drug delivery, co-crystals, and separation of chiral isomers [32]. 

2.5.5 Process Dynamics and Control Process control is another very important core chemical engineering discipline. Although in the industry, electrical and instrumentation engineers also specialize in this area. Process control is the general term used to describe the methods for adjusting for changes that occur due to changing process inputs (in a process unit of a chemical process plant). It requires a basic understanding of chemical process operations. Therefore, a background in conservation theory (heat, mass and momentum transport), reaction engineering and thermodynamics is required. In addition, a first course in ordinary differential equations is essential. Process control study in undergraduate chemical engineering presents dynamic processes and the engineering tasks of process operations and control. Areas covered usually include control strategies; design of feedback, feedforward, and other control structures; modeling the static and dynamic behavior of processes; and applications to process equipment.

Chemical Engineering Basic Education and Training 61 Students upon completion of this course will acquire the ability to: • Mathematically develop time domain dynamic models and Laplace domain input-output models for chemical processes for the analysis of process behaviors; • Identify, articulate, and solve linear chemical process dynamics problems, applying knowledge of mathematics, chemistry, and other sciences; • Learn how to apply time-dependent differential equations to real operations, single input/output systems and multiple input/multiple output systems; • Design and carry out laboratory experiments, analyze and interpret data to determine the efficiency of control designs; • Understand process control hardware and how it integrates with the process. The scope and importance of process control technology will continue to expand during the twenty-first century. An undergraduate course in process control is not enough for the chemical engineering graduate to specialize as process control engineer. Additional training in the field is required—either as on-the-job training or as a postgraduate degree skill acquisition in order to be able to operate modern plants. Also, since solutions will be obtained using numerical methods, working knowledge of computer applications and programming is helpful. EV86620 Standby TE86561 ###.# Cooler

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Figure 2.5.10 A Process control panel screen (Image sourced at http://tailcreek.com/ Products/process.htm, 2016).

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Conversely, the major area of focus of chemical engineers in this field will be the process control design. Knowledge of the nature of the time-dependent system, system dynamics, basic chemical process operation, among others, are needed to design a process control system. Alford and Edgar (2017) [33] argue that process control course material being taught currently requires an update. They observed that courses still highlight methods specifically applied to develop the petrochemical industry over 50 years ago, such as Laplace transforms, Bode plots, and Stability analysis based on frequency response. The process control process, as some experts believe, should be taught completely from the perspective of the time domain instead; but others still prefer keeping the frequency domain paradigm, which requires Laplace transforms. Due to advances in biochemical processes, which are mostly run as batch processes, discrete control knowledge at the undergraduate level has become essential. Various forms of proportional-integral-derivative (PID) controllers are used for most batch processes, but their activation, configuration, setpoints and tuning parameters are often time-and process-step dependent [33].

2.5.5.1 Applications of Process Dynamics and Control Global competition, rapidly changing economic conditions, faster product development, and more stringent environmental and safety regulations make process control very key in industrial operation. As a result, new techniques are constantly emerging in the field; they include increased use of simulation for analysis of control systems, soft sensors, controller performance monitoring, real-time optimization, batch process control, and model predictive control. Process control is used to correct the system for alterations in input. Process outputs often fluctuate due to changing inputs. For example, crude oil feed composition may change in fractionation column of a petroleum refinery such that quality of kerosene fraction can be altered. Thus, it will often be necessary to know just how much time will elapse for systems to stop making such significant changes. To correct this, adjustments of certain variables will be made so that the impact of dynamic inputs is significantly reduced. In the same way, in many chemical processes it is desired to operate with certain output conditions, such as a specific pressure or an optimum reaction temperature, so that the desired product is safely and economically obtained. Thus, the unit operation in those chemical processes must be adjusted when changes in the input conditions occur (such as feed temperature in a distillation tower, cold water

Chemical Engineering Basic Education and Training 63 flowrate in the shower). To correct the system for alterations in inputs, a manipulated variable (usually associated with opening and closing of some valve) is usually changed from a remote area known as a process control unit.

2.6 General Skills in Chemical Engineering Education A chemical engineering degree program offers many skills that are valued in varied industries and other sectors. The generic skills in chemical engineering education include: • Theoretical basis for new technology – chemical engineering degree offers theoretical fundamentals needed to introduce new technology and in advancing the existing one. This is why the scope of the discipline is easily expanding continuously. • Engineering judgement – the discipline provides the basic skills necessary to make engineering judgment amid constraints such as cost, time, safety and environmental concerns, physical and chemical limitations, government regulations, etc. • Problem-solving and analytical skills – chemical engineering offers problem-solving and analytical skill required in developing optimal solutions to economic, environmental and various problems impacting the general well-being of people. This is evident in the ability of graduates to analyze information, interpret and evaluate data, troubleshoot and develop ideas to solve problems. • Other soft skills – ability to work effectively in a team, effective communication, creativity, self-learning ability, computer skills, project management skills, etc.

2.7 New Chemical Engineering Hire Chemical engineers upon graduation from the universities and colleges are not engineers yet. They usually undergo postgraduate training that may last three to five years before they can start functioning independently as engineers. Young chemical engineers often face the biggest question, which is “How can the chemical engineering knowledge acquired from the universities and colleges be matched with what is obtainable in the industry?”

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Understanding the basic chemical engineering concepts is one issue but how to apply those concepts to real-world problems and designs, especially as they are practically being applied by practitioners, is indubitably another issue. Chemical engineering professors teach mainly engineering concepts and leave it up to the student to somehow decipher the industrial applications of those concepts.

2.7.1 Transitioning from the University to Professional Engineering Career Transition from university education to professional chemical engineering career is the critical period for the new hires. New chemical engineers work in diverse industries where chemical engineering principles (as discussed in section 2.5) are applied; others, however, may work in areas where little of the skills acquired from the university can be applied. The industrial sectors of interest to chemical engineering graduates include the energy sector (nuclear power, oil and gas, renewables, etc.); the health and food sector (water, bioengineering, pharmaceutical, food processing, etc.); the chemical and petrochemical sectors; the environmental sector, electronics, and so on. Career options for chemical engineers are discussed in detail in Chapter 4. New chemical engineering graduates employed in any of these foregoing sectors mostly start working as trainee design engineers, assistant process engineers, process engineer associates or process engineerin-training. Process engineering is basically the application of chemical engineering principles to optimize the synthesis, design, operation and control of chemical processes. Though engineering curricula equip graduates with adequate qualifications to launch into a professional career, how these curricula will make graduates fit into professional career is usually not clear. Hence, succeeding in the university is not a guarantee for success at work. Engineering education can be said to be a highly structured curriculum whereas an engineering career constitutes an unstructured environment that presents multidimensional tasks. Baytiyeh and Naja (2011) [34] observed that engineering graduates, as a result of these differences in education and career, usually appear unprepared for the specific challenges they face on the job, such as fitting into a new environment, culture, work politics, power and reward structures, building effective working relationships, being accepted as member of a team, and earning respect and credibility. The first challenge of a graduate chemical engineer is where to locate and secure a job that can be transformed into a sustainable career for

Chemical Engineering Basic Education and Training 65 monetary and professional growth. The engineer, irrespective of the country, may face the following three immediate but short-term options: 1) having the privilege of finding employment in an establishment that fits his or her career goals; 2) accepting the first available offer, even if not satisfying (including offers with little or no professional prospects); and 3) pursuing further education and training. Given the fact the actual engineering career starts from postgraduate industry training, graduate engineers should wisely choose from these options to avoid the risk of accepting job offers in an organization where professional growth will be stunted. Conversely, novice engineers still have the option of changing jobs during early career employment where dissatisfaction exists. The journey of a new chemical engineering hire, otherwise known as a novice chemical engineer, starts from the periphery and then through practice, participation and commitment, the novice becomes proficient and moves into the mainstream (center) where he or she becomes a full member of the chemical engineering community. During their time at the periphery, they are usually assigned to an experienced engineer who will lead and oversee their activities. These trainee chemical engineers yet are confronted with the realities of sustained full-time work. The challenges in the work setting includes corporate environmental constraints, job security, specific professional skills required to tackle multidimensional tasks, administrative tasks, working under pressure, dealing with superiors, limited knowledge or skills, fear of failure, working with diverse people, taking responsibilities, communication problem, self-confidence issue, etc.

2.7.2 Job Assignment of a Trainee Chemical Engineer Job designation for beginning chemical engineers in a chemical, petrochemical, oil and gas, industrial biotechnology and/or pharmaceutical companies can be any of such titles as trainee engineer, assistant process engineer, junior process engineer, research associate or associate/assistant process development engineer, etc. The engineer-in-training are usually assigned to assist technical process facility engineers and management, in the identification, analysis, design and implementation of improvement opportunities in a chemical engineering establishment. They would be assigned to work with a lead process engineer or principal investigator or senior process development/ bioprocess engineer in any of the following; 1) process definition for a new production platform, 2) process optimization/improvement for an

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already existing process for productivity improvement and cost reduction, 3) Scale up of defined production process to pilot and/or commercial scale, 5) Equipment design and selection, and 6) Process and technoeconomic modeling, etc. For upstream process development, technical activities the new hire can participate in include running and optimizing reactors and processes (fermentation/cell culture in bioreactors), defining boundary conditions, understanding scale-up factors, strain screening and media optimization in shake flasks and laboratory scale reactors, enzyme assays, analytics and data analysis. For downstream process development, some of the tasks include defining recovery unit operations, optimizing each unit operation to improve recovery, defining scaling parameters, scale up, analytics and data analysis. New hires are expected to keep cost in mind when handling any task that involves developing/optimizing a process and should refer to their process and technoeconomic modeling to understand cost drivers and processes that need to be on the critical path for development. Required working tools Designing processes and systems in chemical processing industry can be one of the more challenging tasks. Tools that help simplify the tasks have been created and are continuously being upgraded. Some of the tools include Aspen HYSYS, Superpro, Schedule pro, Matlab, Labview, Microsoft visio, etc. They are some of the tools that allow engineers to screen data, calculate or perform preliminary simulation or modeling, equipment sizing and so on.

2.7.3 Required On-the-Job Training and Skills New process development engineers are usually sent for courses like modeling using specific software programs like Aspen or Superpro, training on use of specific equipment like bioreactor, column chromatography, distillation column; design course (advanced simulation and analysis software such as HYSIM, HYSYS, PRO II); process synthesis course, etc. Other trainee engineers who are taking project engineering path can be sent to training on the expert use of project planning software such as primavera and advanced Microsoft spreadsheet, etc. There are broad industrial sectors hiring new chemical engineers. Even within a chemical processing industry, there are several areas or specialty for the new hire, such as production, process, laboratory, process control, project management, research and development, quality, maintenance and operation, etc.

Chemical Engineering Basic Education and Training 67

Figure 2.7.1 On-the-Job Training of New Chemical Engineering Hires.

Chemical engineers-in-training receive career experiences over a period. They are offered a customized training plan with objectives in different technical disciplines. The standard practice is to assign them to mentors who will provide leadership and technical training and development in a variety of the industry’s functional areas. The overall aim is to provide the beginning engineer with optimum work and life learning experiences. The core engineering training areas are: • • • • • • • •

Engineering design, simulation and modeling software tools Design engineering Process engineering concept and design Process safety engineering and management Process control, instrumentation and automation Biochemical/biopharmaceutical processes Applicable codes and standards Cost engineering

Other technically related areas are: • Project management • Quality engineering and quality assurance • Maintenance management

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Operations engineering Supply chain management Health, safety and management Organizational leadership and strategic decision making Sustainability Production management Probability and statistical tools for plant improvement

This phase of training provides the young engineer with the necessary background to support and register as a professional engineer. Required Skills Generally, in the light of the broad view of chemical engineering, Molzahn and Wittstock (2202) [35] suggested that a trainee chemical engineer needs to have the following skills: • Technical Competence: understanding the physiochemical and chemical engineering principles; • Methodological Skills: this is the ability of the engineer to use the technical knowledge acquired to find solutions to new problems and or improvement/solution to existing problems; • Systematic Skills: ability to think creatively, analyze problems and process solutions to problems in a systematic way. • Social Competence: communication skills, that is the ability to work in a team, including multidiverse and multidisciplinary teams. Ability to contribute and make constructive criticism and suggestions in a team. • Entrepreneurial Skills/Working Independently: ability to work with little or no supervision. Ability to organize, take initiative, plan and set meaningful priorities, implement decisions, judge what is feasible and satisfy customers. Customers can be internal or external. Internal customers can be the young engineer’s superior, manager, peers, employers, and so on, while external customers are the clients, government, etc.

2.7.4 Expected Challenges for the New Chemical Engineer The major challenge novice chemical engineers face is understanding of the chemical/production platform and or design engineering procedure of

Chemical Engineering Basic Education and Training 69 the employer in a timely manner to be able to contribute to process development, improvement or intensification. The key expected challenges new chemical engineering hires can face are summarized as follows: • They are overwhelmed by the tasks assigned to them and struggle with multitasking or prioritizing tasks. Hence, they will face aggressive timelines and budget constraints (budget in terms of man hours). Tasks are created, and hours assigned to the tasks created. This is usually translated to costs. The entire chemical/process team is usually under pressure to meet project demands, just as industries are increasingly becoming more diversified and competitive. Part of the job function of chemical process engineers involves designing capital efficient process and operating solutions, and this must be done within budgeted time and hours. This is more so as new processes would require an investment in research and development (R&D) and pilot testing. This scope is always tied to budget in terms of time and cost. The process must be reviewed severally and verified before being approved for construction. CAPEX and OPEX estimates will usually determine the viability or otherwise of a process. More so, engineers would be required to demonstrate that intensive planning and extensive testing have been done in order to win the confidence of upper management. The foregoing is one major challenge a new chemical engineering hire should expect. Multitasking skill and adequate prioritization of tasks is the key to success here. • They are expected to be productive. Process engineering teams across industries are always in the business of analyzing and processing several pieces of data necessary for process and product development. In the industry, the job of chemical engineers goes beyond what students are taught in the classroom. It requires robust thinking, heuristics, analysis, large-data processing and management. Engineering teams usually do not have adequate time to develop the level of details required in various phases of a process or product development such as feasibility studies, detailed process and instrumentation diagrams (P&IDs), equipment selection and sizing, HAZOP/HAZID studies, technical document and information management, construction, commissioning and startup. Resources are, hence, always the constraint

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Introduction to Chemical Engineering and for the team leader to succeed, team members are expected to work at optimum, including new hires. • A quick understanding of the chemical/production platform of the employee in a timely manner is critical to success of the new hire. The new hire must understand that different industries have different work methodology and practices. Though the engineering principles would likely be the same, new technologies and practices may have evolved faster in some industries/organizations more than others. • During process/product or project development phase, chemical process engineers will be faced with the enormous task of on-site modifications, changes, supervision, data and technical document management, and so on. Engineers struggle with ensuring that several P&IDs approved for construction are being maintained. A lot of interface problems are expected at this stage due to several contractors, subcontractors and vendors that are involved. A whole lot of interface issues that require efficient interface management would likely come up during this stage. New hires are likely to be assigned to a specific area to focus in.

2.7.5 Career Growth Path and Success Factors For a young chemical engineer who wants to succeed, continuous on-thejob learning is highly important. The beginning engineer needs to be participating in educational enhancement opportunities, maintaining personal networks, participating in activities of professional institutions, reading professional publications, studying corporate technical plans and procedures, learning and mastering software tools, participating in online and instructor-led tutorials, setting career objectives, etc. Chemical engineering is very wide-ranging; engineers are expected to be flexible enough to adapt to any of these broad areas. Core chemical engineering subjects—reaction engineering, thermodynamics, separation techniques and transport phenomena allows chemical engineers to move from, say, a process engineering role to environmental engineering and any other arears of specialty. Also, young engineers need to understand the necessary tools to ensure success in the new trend in chemical engineering which is tailored toward four approaches. These include materials with controlled structures, process intensification, product-oriented engineering, and multiscale simulation and modeling from the nano or molecular scale to production scale (refer to Section 9.4).

Chemical Engineering Basic Education and Training 71 There are two career paths for chemical engineers—technical or managerial. For the technical track the process development engineer advances to senior process development engineer, followed by principal engineer. For the managerial path, they advance from senior engineer to associate director, followed by director, senior director, vice president, senior vice president and finally chief technical officer. Critical chemical engineering knowledge areas new hires can pay attention to includes in-depth understanding of energy and material balance, heat and mass transfer as well as process design and equipment selection and design. Engineering is a community where engineers collaborate with members in a multidisciplinary team; good communication, thus, is a very key success factor in the chemical engineering profession. General critical success factors for engineers are discussed in detail in Section 4.4. Generally, to be successful, the engineer-in-training should be highly motivated, well-rounded, able to prove his or her engineering and leadership potential.

2.8 Registration of Engineers Several institutions of chemical engineering exist in countries that have universities and colleges that offer a chemical engineering degree. Normally, a graduate is qualified to pursue professional or chartered status after at least 3-4 years’ experience as engineer-in-training. This requirement varies across the globe. To demonstrate their experience, candidates are normally required to assemble evidence that shows their competence, work experience and commitment in the form of technical report. The report will undergo peer review. Candidates may also be required to attend seminars and tutorials that will culminate in writing a qualification examination. The professional body aids members’ continuing professional development in the field and helps in reshaping and advancing chemical engineering. In addition, the body exposes members to a wide range of chemical engineering knowledge areas other than the area individual members have specialized in. Chartered status is important as it will enable professionals to demonstrate diverse technical leadership, development and general experience that well-rounded engineers need. Chemical engineering institutions that are globally recognized are the Institution of Chemical Engineers (IChemE) and the American Society of Chemical Engineers (AIChE).

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2.8.1 Institution of Chemical Engineers (IChemE) The Institution of Chemical Engineers (IChemE) is a globally recognized chemical engineering body that offers chemical engineers around the world the opportunity to improve their professional status, enhance their knowledge and network with peers. International membership of the institution exceeds 40,000 in around 100 countries. It promotes competence and a commitment to best practice, advances the discipline for societal gain and supports the professional development of members. The institution published the advantages of membership on its official website (www.icheme.org) [36] and they are explained as follows: • Professional recognition through widely recognized registrations such as Engineering Technician (EngTech), Incorporated Engineer (IEng) or Chartered Engineer (CEng), depending on their membership grade. • Access to a supportive network of contacts – members can be allocated to one of over 40 regional member groups operating around the world based on their default/mailing address; each group is led by local volunteers who support the members in their area with a program of activities such as networking events, lectures and presentations, social events and site visits. • Technical events and interactive webinars organized by 20 special interest groups (SIGs) that cater to a wide range of industry sectors and professional interests. The SIGs are run by volunteers who organize activities on their area of expertise. • Latest news and in-depth technical articles in The Chemical Engineer magazine and at www.thechemicalengineer.com – available in print and/or digital version. • Free access to the Knovel e-library containing over 300 chemical engineering titles, databases and problem-solving tools; members can find answers to technical questions, gain access to information hidden in complex graphs, equations and tables using analytical and search tools, access reliable reference contact across a range of topics including petroleum engineering, sustainability, design, process safety and loss prevention, water treatment, bioprocess and biotechnology, materials selection and safety compliance. • Free online access to loss prevention bulletin for professional process safety engineers and discounted rates for other members which may serve as lessons learned; key features of the

Chemical Engineering Basic Education and Training 73 bulletin include six new issues per year, plus 40 years of previous articles, case studies demonstrating the hazards of real process and plant, technical articles offering practical advice on specific hazards, process safety management systems and good safety practice, Free access to toolbox talks – a series of PowerPoint slide shows that can be used as the basis of short safety talks. • Influence future thinking on energy, diversity, the bioeconomy and more via IChemE’s policy work and engagement outreach. • Discounted rates on IChemE conferences, online and inperson training, ad-hoc events, books and free online access to journals published with Elsevier including Chemical Engineering Research and Design, Process Safety and Environmental Protection, Food and Bioproducts Processing, Education for Chemical Engineers, Sustainable Production and Consumption, South African Journal of Chemical Engineering (open access). • A lively social media community including Interface – a members-only online forum where members can connect with like-minded professionals, share ideas and experiences, offer advice and ask questions.

Figure 2.8.1 In-person Training of Chemical Engineers.

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2.8.1.1 IChemE Membership Grades The IChemE membership grades include: Student Member This category is for chemical, biochemical or process engineering (or related subject) undergraduate students. Benefits include access to membership resources such as digital subscription to magazine (The Chemical Engineer), networking, events and webinars via regional member groups and technical special interest groups, online access to the Knovel e-library and IChemE journals, Student pocketbook, Job-hunters’ Survival kit and Graduates’ Guide, digital logo for business cards, CV’s and email signatures. Students who wish to apply can complete an online form and pay a oneoff fee of GBP 25.00 which covers the entire duration of the undergraduate program. (This fee is current as of April 2019.) Affiliate Member This category is for those that hold CEng registration with another professional engineering institution and those with an interest in chemical engineering but who don’t currently meet the requirements for other grades of IChemE membership (graduates in other degrees). Affiliate Members can access all membership resources including The Chemical Engineer magazine, Knovel e-library, regional member groups and technical special interest groups. Technical Member This grade is for those working in process engineering support roles across industry and academia, who have chemical engineering qualification at level 3 or above. They must have completed a technician training scheme within the chemical and process engineering industry. Technician members receive peer-reviewed proof of their chemical engineering competence, independent validation of their expertise through EngTech registration with Engineering Council, enhanced status in the workplace, a platform to work toward Incorporated Engineer (IEng) status, digital Technician Member logo to use on business cards, email signatures, etc. Candidates who wish to apply for this category can complete an online application form and submit an EngTech Competence and Commitment Report. Associate Member These are members who have degree-level knowledge and understanding of chemical engineering and are essentially working toward qualification

Chemical Engineering Basic Education and Training 75 as chartered chemical engineers. Benefits include access to all membership resources including AMIChemE post nominal letters, the opportunity to apply for Incorporated Engineer (IEng) registration with Engineering Council, a platform to work toward Chartered Member (MIChemE) and digital Associate Member logo to use on business cards, email signatures, etc. Interested candidate can apply online and upload a copy of any degree certificates or transcripts; those without a chemical engineering first degree at bachelor’s level with honors or above, can also upload an expanded CV providing details of work-based chemical engineering experience. Chartered Member Chartered members are awarded the title Chartered Chemical Engineer (C.Eng). This grade shows that a member has professional competence and commitment to employers, policy makers, regulators and society. Benefits include access to all membership resources, in addition to having access to peer-reviewed proof of their expertise, external validation of their expertise through professional registrations such as Chartered Engineer (CEng) and Chartered Environmentalist (CEnv); career development opportunities (independently assessed Chartered Chemical Engineers are most times given extra responsibility); digital Chartered Member logo to use on business cards, email signatures, etc. Additionally, Chartered Engineer members gain the opportunity to apply for Chartered Environmentalist (CEnv), Professional Process Safety Engineer, European Engineer (EUR ING), and Energy Saving Opportunity Scheme Lead Energy Assessor (ESOS LEA). Application to this grade can be done by completing an online form, uploading degree certificate/transcripts and/or technical report (as instructed by the IChemE membership team); a completed compliance and commitment (C&C) report (signed and dated by applicant and his verifier/s) and details of applicant’s referees. Fellow This is the highest grade of membership and is reserved for Chartered Chemical Engineers who have made a significant contribution to chemical engineering, which includes training or mentoring, working on committees, research, attending professional meetings and so on. Becoming a Fellow indicates that the member has acquired experience, technical excellence, leadership skills and has strong commitment to the profession. Benefits includes access to all membership resources, in addition to professional recognition of the individual’s senior responsibility in chemical engineering, use of FIChemE post nominal letters, Fellow badge and digital logo (to use on business cards, email signatures, and so on).

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Chartered chemical engineers who want to become a Fellow can apply online, providing details of experience in an important position of responsibility in chemical engineering (max 100 words); contribution to the profession (max 100 words); statement describing why and how the work the individual has undertaken over the last five years satisfies the requirements for Fellow status (approx. 300 words); an up-to-date, detailed résumé; organization chart showing candidate’s current position; a minimum of two referees – either both Fellows, or one Fellow and one Chartered Member. More information is available at the institution’s website: www.icheme.org.

2.8.2 American Institution of Chemical Engineers (AIChE) American Institution of Chemical Engineers is an organization for chemical engineers and those in chemical engineering support roles, working across a wide spectrum of chemical engineering career options such as the areas discussed in chapter 4. It has more than 60,000 members from over 110 countries. AIChE membership promotes professional development, and intending members can join at any stage of their careers. The institution published the advantages of membership on its official website (www.aiche.org) [37] and they include: • Access to annual subscriptions to CEP Chemical Engineering Progress – for latest on chemical engineering developments and breakthroughs; AIChExchange, AIChE SmartBrief – most important weekly business and technology news and AIChE eLibrary, which provides powerful, interactive, 24/7 online access to more than 250 full textbooks, handbooks, standards, databases, video research tips and  presentations through the Knovel Life Sciences collection. • Substantial savings on all AIChE publications, including AICHE Journal (members save more than 85%), Bioengineering and Translational Medicine – New Open Access Journal, Biotechnology Progress, Environmental Progress & Sustainable Energy and Process Safety Progress. Members can also receive a 35% discount on select books from AIChE and Wiley such as Guidelines for Risk Based Safety and Distillation Troubleshooting. • Conferences and training – opportunity to learn from experts, discover new developments in core process areas, specific topical areas, emerging technologies, including sustainability, fuel cells, biotechnology, and more; also, members network

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• • •

and build new alliances; members can also get six free annual credits they can use for AIChE webinars and conference presentations. Access to exclusive online member communities, technical divisions, local sections, and forums and technological communities – for professional connections, learning, information gathering, technology transfer, affiliation, personal and professional growth and leadership. Members also get substantial discounts on courses, conferences and conference recordings and webinars at the AIChE academy. Insurance products – members-only group rates on comprehensive insurance products in the US. Members also get discounts at hotels, stores, UPS shipments, business services, cruises, online shopping, and so on. Other benefits include savings on books, magazines and journals, free career resources and services; virtual career fairs (connecting with leading chemical process industry employers).

2.8.2.2 AIChE Membership Grades The AIChE membership grades include: Professional Members Professional members are those who possess AIChE membership. They enjoy the benefits of membership described above. Additionally, they can nominate and vote for officers and directors. They can qualify for senior membership after four years. Candidate can apply online for membership, dues are applicable. The institute has also created membership applications translated into different languages. Senior Member Four-year regular members can apply for senior member grade by submitting required documentation. Senior members enjoy the privilege of holding office, voting on constitutional amendment, nominating and voting for officers and directors of the profession. Fellow This is the highest AIChE’s grade of membership and can be awarded upon recommendation by the institutes’ admissions committee. The committee

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receives nominations and processes documentations of the nominated members. Senior members who have spent three years and at least cumulative 10 years as members of the profession are eligible for nomination. Additionally, the senior member should demonstrate significant accomplishments in, and contributions to, the profession. Senior members or fellows would be required to attest to professional accomplishments of the nominee. Details of membership rates by category and dues waivers and reductions can be found at the institution’s website.

3 Chemical Engineers’ Areas of Expertise 3.1 Introduction Chemical engineering has strong expertise in areas such as various types of energy production, biochemical/biomedical engineering, safety and environment, Iron and steel making, food processing, mineral processing, polymer and composites. Chemical engineers are increasing the pace of development for large-scale bioprocesses and chemical processes through the application of basic principles of chemical engineering together with front line concepts of molecular biology and chemistry, respectively. Such principles as bio reaction kinetics, reactor selection, design, scale up and control, and so on, are being applied. The American Institute of Chemical Engineers (AIChE) has published a list of the ten greatest achievements of chemical engineering in the world. The achievements are briefly explained in simple terms as follows: 1. Being able to split the atom and isolate isotopes in what gave rise to the creation of an atomic bomb that helped in bringing the Second World War to an end. The atomic bomb itself should be likened to a reactor. 2. Mass production of polymers which are used in making all kinds of plastics for electric insulation, electric accessories, clock bases, electrical appliance handles, television, automobile fittings, chairs and tables and numerous other uses of plastic in the world. 3. Application of the concept of unit operations to human body organs leading to the manufacture of life-saving medical devices such as dialysis system, artificial organs and so on. 4. Development of technology to mass produce essential drugs for all (mass production of the antibiotics developed by Sir Arthur Fleming).

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Introduction to Chemical Engineering 5. Commercial production of synthetic fibers used in making all kinds of clothing and clothing materials that keep us warm, comfortable and healthy. 6. Ability to condition air to very low temperature to the point of condensing to a liquid, such that its constituents can be separated. One of the elements, nitrogen, separated can be used to recover petroleum, freeze and preserve food, produce semiconductors, or prevent unwanted reactions (inert characteristic), while another component, oxygen, is used to make steel, smelt copper, weld metals together, smelt copper, live in confined spaces, and support the lives of patients in hospitals. 7. Development of hazardous waste elimination/or treatment process/systems such as reformulated gasoline (high-octane gasoline) production system, catalytic converters, smoke stack scrubbers, wastewater treatment plants and other environment cleaning processes and systems. 8. Design and production of fertilizers that help in the rapid growth of food crops; thereby making food abundant to man. This is in addition to development of food processing techniques. 9. The design, construction and operation of a large-scale petroleum refinery that transforms crude oil into various useful products such as gasoline, liquefied petroleum gas, lubricating oils, synthetic rubber, kerosene, synthetic fibers, diesel oil, asphalt, wax and so on. Most organic chemicals and petrochemicals are produced from petroleum products. In fact, our contemporary life cannot be defined without this technology. 10. Development of synthetic rubber such as gaskets, tires (for vehicles, bike, roller-blade and others), hoses, conveyor belts, footwear, and so on.

Chemical engineers in the twenty-first century have extended chemical engineering application to biology, material, environment, food, pharmacy, renewable energy and resources, and other fields and are integrating new knowledge to add to their knowledge base. Chemical engineers’ areas of expertise and great achievements in the fields of energy, the environment, biomedicine, electronics, food production, materials and the space program are described in detail in the following sections.

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Energy and Sustainability Eletronic Sector

Materials

Chemical Engineers Areas of Expertise Food Sector

Space Program

The Environment

Biomedicine /Biotechnology /Bioengineering

Figure 3.1 Chemical Engineers’ Areas of Expertise.

3.2 Energy and Sustainability Segment Chemical engineers have strong expertise in energy. Energy is what sustains contemporary society. Human life generally depends to a large extent on energy. In nature, energy exists in various forms. Alternative energy such as solar or wind energy is difficult to utilize efficiently but the more concentrated ones such as fossil fuels are easier to utilize. The present predominant global energy source, petroleum or fossil fuel energy, is a finite resource, so chemical engineers constantly seek better ways to find, extract and refine or utilize them. Hence, they design processes to efficiently extract the resources from the ground (onshore or offshore), treat, blend, refine and transport them to end users. On the alternative also, they are seeking ways of utilizing other forms of energy. Consequently, chemical engineers working on renewable energy have been responsible for the development and application of new chemical compounds to increase the energy transfer efficiency of solar power panels or wind turbines. With a background that includes physio-chemical and biological energy transformations, transport of heat and mass in fluids and solids, materials for energy capture and storage, process design and simulation, process analysis, and full life cycle analysis of energy and mass flows, a chemical

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engineering education provides the ideal skill set for meeting a wide range of energy problems. Much of the research conducted in complex fluid and polymers by chemical engineers has direct applications in energy such as in  liquid fuel cells, conducting lubricants, electrolytes for lithium metal batteries, nanoparticle fluids for carbon capture, nanomaterials for biomass conversion, and so on.

Figure 3.2.1 Energy Production (Credit: Schlumberger).

Energy demand has been on the increase and will continue to rise. This trend will lead to more emphasis on fundamental engineering design as there will be increasing need to design and redesign sustainable chemical processes that are energy efficient. Main chemical engineering fundamental areas, such as chemical kinetics and reaction engineering, catalysis, separations and process design shall be focused on. A major challenge is how to make renewable processes for producing fuels and chemicals cheaper than fossil fuels. How to improve the efficiency of the various sustainable energy generation is currently the effort of chemical engineering research in this sector.

3.2.1 Petroleum Refining Chemical engineers use complex chemical separation and conversion processes to turn crude oil into gasoline, diesel and jet fuel, kerosene, lubricating oils, and numerous other end products, as well as many intermediate petrochemical products. Petroleum refineries are marvels of modern engineering. Within a refinery lies a maze of pipes, distillation columns, and chemical reactors that turn crude oil into valuable products. Crude oil molecules come in all shapes, sizes and forms; therefore refining consists of sorting, splitting apart, reassembling and blending these hydro molecules. The foregoing is the range of the final products. This is accomplished by physical separations and

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chemical reactions and temperature, pressure and catalysts (consisting of crystalline zeolite, matrix, binder, and filler) play a dominant role. The petroleum refining process is a series of complex and highly coupled interactions between the catalyst, hardware, crude oil (feed) and products.

Some of the important chemical process operations instrumental in modern-day refining include: • • • • •

Thermal cracking, Distillation, Fluid catalytic cracking, Hydrocracking, and Reforming.

Figure 3.2.2 A Petroleum Refining Company in Niger Delta, Nigeria.

Petroleum refinery and gas processing plants can as well become a time-bomb if there is design or process control defect. The process design, as well as other chemical and gas process plant design and operation, is a high-risk endeavor. This is why chemical engineers’ ingenuity is highly appreciated.

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The chemical engineering community is thus constantly working to modify and improve the petroleum-refining processes. Their objectives are to: • • • • • •

Achieve higher conversion rates and greater yields, Improve overall energy efficiency, Produce cleaner fuels, Reduce refinery emissions, and Reduce operating costs, Lower risks of hazards.

3.2.2 Synthetic Liquid Fuels Synthetic fuel is a liquid fuel obtained from syngas (a fuel gas mixture consisting primarily of H2, CO and very often some CO2), in which the syngas was derived from gasification of solid feedstocks such as coal or biomass or by reforming of natural gas.

3.2.2.1 Fuels from Biomaterials Chemical engineers are using engineering principles to extract biomass energy. Biomass is plant material—fast-growing trees and grasses, grains, corn, sugar cane, wood scrap, even woody leaves and stalks and garbage, are now widely used to produce ethanol, which is used as a gasoline substitute. This type of fuel can also be converted into gaseous and liquid fuels for electric power generation and automobile propulsion. The fuel can also be blended with premium motor spirit. A process company in Houston, US, is set to commercialize a Gas Technology Institute process for converting biomass directly into cellulosic gasoline and diesel fuel blendstocks. The technology, called integrated hydropyrolysis and hydroconversion (IH2), is a two-step continuous process that can accept virtually all classes of biomass. Ethanol is made by fermenting biomass rich in carbohydrates (starches and sugars). It is a gasoline-like alcohol. Chemical engineers and others are currently using it widely in the production of a gasoline ethanol mixture, raising octane while reducing pollutants. This can serve as a direct gasoline substitute with engine modifications. Biodiesel is made from animal fat, vegetable oils, and even recycled cooking grease. It is cleaner than fossil-fuel diesel and serves as a functional

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Figure 3.2.3 Biomass used for solid fuel (Image sourced at: http://www.filtsep.com/ view/16678/energy-materials-processing-filtration-and-the-fuels-of-the-future/, 2014).

alternative diesel. Already diesel engines that run on biodiesel have been developed. Forest and agriculture residues, municipal wastes, and landfill gases can be used to generate electricity in four basic methods now being used: • Direct firing, where biomass is burned directly; • Co-firing, where biomass is mixed with fossil fuels; • Anaerobic digestion that promotes biomass decay to produce methane, the principal component of the natural gas we burn today;

• Biomass gasification that turns biomass into synthetic gas. Recently, process engineers in Canada have been developing what is said to be the world’s first industrial-scale plant to produce liquid fuel from municipal solid waste. The plant’s capacity is 10-million gal/year of methanol from 100,000 metric tons per year (metric tons/year) of garbage, followed by ethanol, under a 25-year supply contract with the city of Edmonton. The garbage represents 40% of the city’s waste that is currently land-filled because it cannot be recycled or composted. Also, the world’s first plant for the production of BIODME (dimethyl ether) was inaugurated in Sweden. The pilot plant constructed uses gasification technology to convert black liquor from the mill into syngas,

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which is then cleared and conditioned before being fed to a DME processdevelopment unit. Heavy-duty trucks with engine adapted for DME fuel have already been developed. DME filling stations are also being constructed to support the DME fleet. Brazil and Sweden are two countries with full-scale biofuel programs.

3.2.2.2 Electricity Generation from Coal Coal is the most abundant fossil fuel on Earth. Coal is primarily used as a solid fuel to produce electricity and heat through combustion. It will outlast crude oil. Coal exists in solid and semi-solid form. But technology to convert coal to liquid and gases are now in place. The liquid coal can become a replacement for petroleum and so can be used in making various petroleum products. Coal is the dominant source of electricity generation. Per the US Energy Information Administration report on June 1, 2011, 93% of all coal in the US is consumed by the electric power sector (electric utilities and independent power producers) and is the overriding force for total domestic coal consumption. Of total power generated in the US, 46% was done using coal, while 68.7% of China’s electricity comes from coal. Also, 77% of South Africa’s energy needs are provided by coal, per the Department of Energy. The country’s electricity supply commission produces 95% of electricity used in South Africa, and its coal-fired stations produce about 90% of electricity produced by the utility (http:// www.statssa.gov.za/). The utility is the largest producer of electricity in Africa and is among the top seven utilities in the world in terms of generation capacity and among the top nine in terms of sales (Wikipedia). Coal accounts for 36–39% of the total fuel consumption of the world’s electricity production (http://www.energy.gov.za/files/coal_frame.html). South Africa has the commercial plant producing liquid transportation fuels and other products from coal. Gasification combined with FischerTropsch technology is currently being used by the Sasol chemical company of South Africa to make motor vehicle fuels from coal and natural gas. The hydrogen obtained from gasification on the other hand can be used for various purposes, such as powering a hydrogen economy, making ammonia, or upgrading fossil fuels. According to Wikipedia, world coal consumption was about 7.25 billion tonnes in 2010 and is expected to increase 48% to 9.05 billion tonnes by 2030. China produced 3.47 billion tonnes in 2011. India produced about 578 million tonnes in 2011. The US consumed about 13% of the world total in 2010, producing 951 million tonnes.

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Figure 3.2.4 Clean Coal Processing Facility (Image sourced at: http://www.filtsep.com/ view/16678/energy-materials-processing-filtration-and-the-fuels-of-the-future/, 2014).

Chemical engineers are currently researching less expensive and cleaner coal-conversion processes. They significantly improved the environment by developing integrated combined-cycle gasification (IGCC) power plants. In this plant, coal is first turned into a synthetic gas in IGCC power plants. The syngas is cleaned to remove unwanted pollutants and then burned in a gas turbine. The exhaust from the primary turbine is used to generate steam for a secondary turbine that generates additional electricity. The power system design is the same as the IGCC system in the front end (i.e., gasification section without heat recovery and the gas-clean up section) but differs from IGCC in the back end (i.e., the power generation section).

3.2.3 Hydrogen Fuel Hydrogen gas is rarely found in large quantities in nature. Its chemical properties allow it to combine easily with other elements to form other molecules (an example is water molecule). Seventy percent of the Earth’s surface is water; hydrogen therefore is in ample supply. Hydrogen has the highest energy content in relation to weight of any fuel – 52,000 Btu per pound. It has about 25% greater efficiency than gasoline. Hence, portable gasoline electric generators used in a variety of applications can be replaced with quieter, cleaner, more efficient hydrogen fuel cells. Hydrogen can be generated in various ways. Chemical engineers design large-scale plants that produce hydrogen directly or indirectly. The gas

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can be produced from natural gas (coal-derived synthetic gas), or from organic materials such as bio-waste, solid waste, landfill gases or biomass, or liquid hydrocarbons by steam reforming or indirectly as a by-product of industrial operations such as thermal cracking of hydrocarbons (petroleum refining) and the production of chlorine and, to a lesser extent, by the electrolysis of water, which is a practically inexhaustible source. Other ways include low-pressure and low-temperature fuel processors that can produce hydrogen from hydrocarbon fuels; water splitting, biomass and wastewater reforming, and renewable electrolysis. At Stanford, chemical engineers have designed a catalyst that could support the production of huge quantities of pure hydrogen through electrolysis—the process of passing electricity through water to break hydrogen loose from oxygen in H2O. Fuel cells are used to turn hydrogen fuel into energy. Hydrogen in fuel cells, when electrochemically combined with O2 produces water, heat, and electricity. This is why hydrogen fuel cell cars are said to be utilizing clean energy. The most well-known application of fuel cells was aboard NASA space shuttles to provide electricity to various systems. Fuel cells provide electricity in a manner similar to batteries. Fuel cells can continue to provide energy, so long as the hydrogen gas is present, but a battery has a finite storage of energy.

3.2.4 Solar and Wind Energy Renewable energy is another area chemical engineers have developed strong expertise in. Renewable energy refers to energy collected from resources which are naturally replenished on a timescale, such as that from solar, wind, tides, waves, rain and geothermal heat. The energy generated here is usually environment friendly, unlike fossil fuel energy. However, efficiency of the technology currently in place for existing renewable energy generation is still low. Chemical engineers are hence working in collaboration with other scientists to achieve highly efficient and less expensive renewable energy. They have been utilizing their knowledge of both material science and heat transfer in designing systems for collecting solar energy and converting it to electricity. They also contribute in developing materials used in fabricating wind mills. Germany’s renewable energy generation, for instance, accounted for about 30% of the country’s electricity needs in 2014, wind and solar particularly. This was more than double the nearly 13 percent of US electricity supply from renewable energy, in the previous year [38].

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Figure 3.2.5 Picture Depicting Renewable Energy (Image sourced at: www.zmescience. comon, 216).

The International Energy Agency estimates renewable energy will become the dominant energy source in the world in a couple of decades, thereby gradually replacing fossil fuel energy. Given the characteristic intermittency of solar and wind energy resources, efficient energy storage technologies are necessary. Nanoscale semiconductor materials present exciting prospects for efficient and cost-effective harnessing of solar energy in next-generation photovoltaics. As a result, chemical engineers in Cornell University are working to understand and control chemical and photophysical aspects of interfaces in nanocrystal-based solar cells and are linking computational and experimental tools to ascertain the assembly of nanoscale semiconductor building blocks toward metamaterials with tunable electronic and optical properties for high-performance solar energy capture. Their research in this area is focusing on nanoscale materials for high-performance next-generation lithium ion batteries and novel materials for high-capacity thermal energy storage.

3.2.5 Nuclear Energy Chemical engineers have strong expertise in the design, development, monitoring, and operation of nuclear power plants in the safest, most efficient way possible. This includes the production, handling, use, and safe disposal of nuclear fuels. Principles of chemical engineering are applied in the design of a nuclear reactor. Design and operation of a nuclear reactor requires thorough engineering judgement due to high danger that

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radioactive materials pose to mankind and the environment. However, nuclear power plants create less air pollution than conventional power plants. Nuclear energy generates much less greenhouse gas than does energy from fossil fuels. Chemical engineers in this area of specialty are constantly working to improve safety, increase power output, and maximize the operating life of nuclear power reactors.

Figure 3.2.6 Nuclear Power Plant (Image sourced at: http://www.filtsep.com/view/16678/ energy-materials-processing-filtration-and-the-fuels-of-the-future/, 2014).

3.3 Food Segment Food chemical engineers are those chemical engineers who work in the process areas of a food manufacturing company as well as those who conceive, design, test, and scale up revolutionary food-processing techniques. Engineers here research, scale-up and install equipment for a plant process. Chemical engineers develop advanced materials and methods used

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for, among other things, modern packaging, chemical and heat sterilization, and monitoring and control, which are vital to the highly automated facilities for the high-throughput production of safe food products. Chemical engineering unit operations and methodologies used in food production include: • • • • • • • • • • • • • •

Drying Milling Refrigeration Heat and material transfer Membrane-based separation Concentration Supercritical extraction Centrifugation Fluid flow and blending Powder and bulk solid mixing Pneumatic conveying Process modeling Hydrogenation/dehydrogenation Monitoring and control

Chemical engineering unit operation and methodologies being applied in food industries as listed above, involves interdisciplinary teamwork, which, in addition to the expertise of chemical engineers, draws on that of food technologists, microbiologists, chemists, biochemists, geneticists, and others.

Basic Contributions of Chemical engineers in food processing include: • Design and construction of plants for commercial production of fertilizers, pesticides, and herbicides that protect and enhance fruit and vegetable growth; • Application of chemical engineering principles in food processing and packaging that help improve taste, appearance, and nutritional value while increasing safety, convenience, and shelf life; and • development of new sterilization techniques that protect food against spoilage and people against foodborne illnesses, and so on.

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Figure 3.3.1 A Food Processing Plant (Image sourced at: http://www.ensepatec.com/en/ products/horizontal-separators/horizontal-ko-drum.html, 2014).

Chemical engineers have been applying the conceptual and detailed process design methods in food industry in the following ways: • Performance of an economic analysis on potential food processing technologies to determine if an approach can achieve the desired price target; • Development of a new process flow diagrams (PFDs), process and instrumentation diagrams (P&IDs) and material balances for new systems or redesigning existing systems and integrating several new unit operations into the process; • Development and maintenance of a food process equipment list, automated valve list, PSV lists, control valve list, instrument list, manual valve lists, line lists, and steam system component list; • Optimization of utilities usage to reduce food product costs; • Optimal production of a fresh high-quality food products; • Facilitation of a process hazards analysis (PHA) to analyze any potential hazards associated with a food process, as well as maintain the list of action items generated from the PHA (ref. Section 6.3 for details); • Improvement of a food product safety; • Development of a solids handling system to automate the addition of reducing employee contact and charging times; • Development of a flexible multifood product systems; • Development of a heat recovery process – specified tanks, pumps, heat exchangers, instrumentation, and operational

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sequencing to reduce or eliminate additional heat input to a food reactor after the initial batch process; Development of a solids handling system to automate the addition of catalyst and feedstock to a food reactor to reduce employee contact and charging times; Improvement of heat history and reduction of product degradation during processing; Development of a commissioning plan for a turnkey food processing system; Specification of instrumentations including an in-line process analyzer, flow meters, level gauges, pressure and temperature sensors or transmitters;   Development of equipment specifications for all of the equipment in a food processing plant project including the reactors, in-line solid/liquid mixers, agitators, bulk solids handling equipment, heat exchangers, vacuum system and pumps, and so on.

Food engineering/technology is an elective in chemical engineering curriculum. Breakthroughs have been made in several areas such as food production, food improvement, food protection and food packaging. This has been achieved by designing and operating a large-scale fertilizer producing plant, pesticide production plants, flavor and fragrances production plants, and so on. The commercial-scale production of refined sugar, for example, involves a range of chemical-engineering unit operations, which include: • Milling & Mixing – Milling shredded raw materials and mixing with water, • Chemical Process Reactions – Adding chemicals to adjust the pH level to control the acid content, • Separation process – Removing impurities, • Crystallization – Crystallizing the sugar and drying it, and • Filtration/Reverse osmosis – Treating wastewater. Also, high-fructose corn syrup from cornstarch, being applied in foods and beverages, also requires many chemical engineering unit operations which include: • Drying – Dry milling the corn,

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Chemical engineers also developed means of processing, packaging and preserving food. They have tried out several different systems since the end of the last century, beginning in Japan, and also more in Europe and other places. Such systems include: • CO2 emitters; • Multilayer packages that allow heat sterilization right in the container; • Oxygen scavengers such as sachets, extruded scavenging films, scavenging bottle closures which control of O2 degradation reactions in food products; • Ethylene scavenging bags for packaging fruit and vegetables; • Compounds that remove unwanted substances from the foodstuff itself; • High-temperature pasteurization and canning; • Controlled-atmosphere packaging (CAP) and modified atmosphere packaging (MAP); • Food purification system that removes such contaminants as salts, metals, bacteria, fungi, and pathogens, using membrane-based separation systems (explained in Section 2.4.4). Different types of membrane-based separators use reverse osmosis, ultrafiltration, microfiltration, or Nano filtration systems, based on the size and structure of the membrane pores; • Irradiation – which is used to kill microorganisms such as Escherichia coli, Salmonella, and other disease-carrying pathogens, without losing food quality, appearance, or nutritional value; • Production of genetically modified foods using an artificial form of DNA called recombinant DNA (rDNA); • Food Ingredients extraction (proteins and fatty acids) – Proteins account for up to 60 wt.% of algae while another 30% is oil rich in Omega-3 and Omega-6 fatty acids which are healthy body nutrients; • Development of systems with antimicrobial activity which appears to be the most important among them.  • Refrigeration and freezing and many other systems.

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Generally, food chemical engineers can be categorized into two: a) b)

Process engineers whose duties in food industries are listed above, and Chemical engineers who specialize in the science and engineering of food such as biochemical or food chemical engineers.

3.4 Biomedicine (BME)/Biotechnology/ Bioengineering Segment Chemical engineers in this area of specialty have been applying basic principles of chemical engineering together with front-line concepts of molecular biology, in the development of large-scale bioprocesses. Such principles as bio reaction kinetics, reactor selection, design, scale up and control, are being applied to create biotechnology. This area uses living cells, materials produced by cells, and biological techniques developed through research to create products for use in other industries. Chemical engineers in the field have designed processes and commercial production facilities that use microorganisms and enzymes to synthesize new drugs, including the production of antibiotics, interferon, artificial organs, insulin, recombinant DNA, waste reduction and recycling, and insect resistant hybrid plants. They develop and design the processes to grow, handle, and harvest living organisms and their by-products. Modern use of the term biotechnology refers to genetic engineering as well as cell and tissue culture technologies. Biotechnology and biomedical engineering (BME) are also often used interchangeably. United Nations Convention on Biological Diversity defines biotechnology as: “Any technological application that uses biological systems, living organisms, or derivatives thereof, to make or modify products or processes for specific use”. Here chemical engineers design processes that involve genetic engineering, in which recombinant DNA is synthesized and used to produce valuable proteins and other medicinal and agricultural chemicals that would be hard to obtain by any other means. Electric field-induced sorting and separation of proteins and DNA in lipid bilayers and gels for example, is a part of the studies being conducted by chemical engineers in this area.

3.4.1 Biomedical or Tissue Engineering Biomedical Engineering is the application of engineering principles and design concepts to medicine and biology to improve healthcare diagnosis,

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monitoring and therapy. Notable biomedical engineering applications include the development of biocompatible prostheses, various diagnostic and therapeutic medical devices ranging from clinical equipment to microimplants, imaging equipment, regenerative tissue growth, pharmaceutical drugs equipment and therapeutic biologicals. One of the goals of biotechnology or tissue engineering is to create artificial organs (via biological material) for patients that may need organ transplants. Tissue engineering involves the use of living cells as building materials. Engineered tissues are being created to repair or replace damaged or unhealthy organs and tissues.

3.4.2 Biotechnology-Based Chemicals Furthermore, the unstable price of crude oil has enabled rapid advances in industrial biotechnology. The number of biotechnology-based chemicals within the sights of commercial producers is increasing. Detailed industry and market analysis for six biotechnology-based chemicals include citric acid, glutamic acid, lactic acid, lysine, polyhydroxyalkanoates and threonine. These chemicals are produced by microorganisms without Table 3.4.1 World Consumption of Biotechnology-Based Chemicals - 2009a Chemical

Quantity (1,000 m.t.)

Average annual growth rate, 2009–2014a (%)

Citric acid

1,500–2,000

4.7

Glutamic acid b

2,500–3,000

3.9

Latic acid c

350–400

7.2

Lysine d

1,000–1,500

3.9

Polyhydroxyal-kanoates (PHA)

1.0–2.0

>25e

Threonine

150–200

5.1

Where: a. Volume Basis. b. Calculated as monosodium salt because glutamic acid is mostly consumed as the flavor enhancer monosodium glutamate. c. As lactic acid, its salts and esters. d. As L-lysine hydrochloride. e. Conservative estimate; 2010 production capacity is sufficient to support an average annual growth rate of more than 100%. Source: SRI Consulting in March 2011 issue of Chemical Engineering, p. 19.

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being challenged by synthetic production routes, and they have already achieved commercial status, and are considered important chemical building blocks [41].

3.4.3 Pharmaceutical Engineering Pharmaceutical Engineering is sometimes regarded as a branch of biomedical engineering, and sometimes a branch of chemical engineering; in practice, it is very much a hybrid sub-discipline just like many BME fields. Notwithstanding those pharmaceutical products directly incorporating biological agents or materials, even developing chemical drugs is considered to require substantial BME knowledge due to the human physiological interactions inherent to such products’ usage. With the increasing prevalence of combination products—a single product comprised of two or more regulated components such as drug/device or drug/device/biologic, the lines are now blurring among healthcare products such as drugs, biologics, and various types of devices. Chemical engineers who specialized in pharmaceutical engineering, design pharmaceutical production processes that involve immobilized enzymes, biological chemicals that can make specific reactions go orders of magnitude faster than they would in the absence of the enzymes. Hence, the pharmaceutical industry recruits chemical engineers who possess a combined expertise in process engineering and biochemistry/molecular biology and or otherwise training in pharmaceutical engineering.

Figure 3.4.1 Biopharmaceutical Laboratory (Image sourced at: https://career.webindia123. com/career/options/engineering/chemical/intro.htm, 2017).

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Biomedical researchers decipher the complex phenomena occurring within the human body, and devise new therapeutic approaches to manage and treat disease. Chemical engineers add their unique expertise to turn many of these promising new concepts into reality. The resulting techniques and devices are now being successfully used to help prolong and improve human lives.

3.4.4 Kidney Dialysis, Diabetes Treatment, and Drug Delivery Systems A kidney dialysis machine is basically a mass transfer device that cleanses the patient’s blood to remove increased levels of salts, excess fluids, and metabolic waste products to control blood pressure and maintain the right balance of potassium and sodium in the body. The machine is used to treat patients who have lost kidney function as a result of disease or injury. Chemical engineers applied mass transfer phenomena, complex flow problems solving techniques through use of Newtonian fluid-mechanics analysis, sophisticated mathematical models, process control technologies that maximize chemical reaction rates and reaction yields, and so on, in developing artificial organs, such as kidney dialysis machines and lung oxygenation units. These engineers have been invaluable in scaling-up promising biomedical discoveries. They have applied chemical engineering principles to the design and construction of commercial-scale facilities producing antibiotics, vaccines, and other therapeutic drug compounds and also in developing automatic insulininjection pumps for treating diabetes. Drug delivery systems have been designed that deliver a drug precisely to the targeted organ. The drug travels through the body to the target site without affecting healthy tissue and organs. The principles of chemical engineering—such as mass and energy balances, transport phenomena, reaction kinetics, and particle technology—are intimately involved in drug delivery (June Wispelwey, “Drug delivery and chemical/biological engineering,” CEP Magazine, March 2013 [42]). Novel effort is ongoing to apply nanoscale structures as drug delivery vehicles that can transport anticancer agents or radioactive atoms within the human body. The aim is to help in destruction of tumors in situ and at the same time reduce unrelated cell damage and other side effects that come with traditional methods of chemotherapy. Another related study on the use of convection to target delivery of therapeutics to brain tumors, is ongoing. Also, chemical engineering researchers are developing in-depth mechanistic mathematical models of cellular differentiation and proliferation to solve

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the mysteries of stem cell biology in addition to many cancers and cardiovascular disorders.

3.5 Electronics Segment Chemical engineers in the electronics industry are involved with material development and production, process control, equipment design, and the manufacturing of microchips, optoelectronics, including thin film transistors, solar cells, and light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), and intricate circuitry. Microchips or integrated circuits are made with small electronic components known as transistors. They provide the source of fast but cheap computing power and can be found in many things, from children’s toys to phones, medical sensors, communications satellites, and automobiles. A chemical engineering researcher, Sam Jenekhe (pictured below) and his group has pioneered the development of organic LEDs (OLEDs), a technology, which has been commercialized, and has drastically changed flat panel displays. OLED uses ground-breaking self-lighting pixels, individually controlled to achieve perfect black and infinite contrast in television.

Figure 3.5.1 Professor Samson Jenekhe (Picture available at: http://depts.washington.edu/ chem/people/faculty/jenekhe.html, 2017).

It is important to note that some universities now have a specialized department for training chemical engineers in this area, for example, the Department of Mechanical, Electronic and Chemical Engineering, Oslo, and Akershus University College of Applied Sciences, Norway. Chemical engineers contributed to advanced semiconductor materials development and the manufacturing processes required in making them.

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Figure 3.5.2 Semiconductor Chip Laboratory (Picture sourced at: http://www.ruf.rice. edu/~che/undergraduate/advising/careers.html, 2014).

Gordon Moore, cofounder of Intel, one of the world’s largest and highest valued semiconductor chip makers, has a background in chemistry. Andrew Grove, a chemical engineer, was the first employee who went on to lead the company in the 1980s and 1990s. Turning silicon into a semiconductor chip requires a multidisciplinary approach. The process begins with the creation of a pure, monocrystalline lump of silicon, usually 6 to 12 inches in diameter. The lump is then sliced into ultrathin wafers, each less than 1/40th of an inch thick. The wafers are first polished using abrasive particles and then put to a successive series of process steps. Generally, four basic processing steps are required as shown below: Deposition of key active materials on the surface of underlying silicon wafer

Selective removal of unwanted materials

Lithography to create the desired connections and circuits

Modification of electrical properties

Each of the steps will require the deposit of a layer of a conductor, semiconductor and or an insulating material. The transistors, capacitors and resistors that eventually make up an integrated circuit can then be produced by these materials deposited in many layers. The method applied for this process is chemical vapor deposition, in which the coating material is formed in a gas-phase reaction and then deposited on the surface of

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the wafer. Nowadays, circuits are built in tiny transistors; hence, a typical dime-sized semiconductor chip can contain millions of microscopic transistors. This is applied in making smart phones, iPods, laptops and smart televisions. A microscopic dust is enough to obstruct flow of current in the individual chips and cause damages. Hence, as more and more transistors are being added to chips which are continuously infinitesimal, keeping the chemicals used in making these chips clean becomes a challenge. The entire processing of these chips, consequently, is done in clean rooms. Chemical engineers design the clean rooms which are specified by number of particles per cubic foot. Filtration systems are designed to capture chemical vapors, microbes, airborne microbes and dust particles. Maintaining the required level of cleanliness and achieving the above process steps require application of some chemical engineering know-how such as fluid mechanics, heat and mass transfer, and crystallization—a knowledge of kinetics can be required during the deposition process. In addition, protective clothing is recommended to be worn by the clean-room technicians, more to protect the semiconductor devices from human contamination than the other way round. Current researches on nanostructure will lead to further advances in semiconductor chips in the future. Chemical engineers will also continue to research ways of optimizing chips production.

3.6 Materials Segment The expanding discipline of chemical engineering encompasses much more than just process engineering. Chemical engineers, particularly those that specialized in polymer, petrochemical or materials engineering have been engaged in the development and production of a diverse range of products, as well as in commodity and specialty chemicals. These products include high-performance materials needed for biomedical, aerospace, automotive, electronic, space, military, environmental and other applications. Chemical engineers design and develop the processes that make a diverse range of materials such as optical fibers, fabrics, adhesives, magnetic media, ultra-strong fibers, Organic Dye Sensitized Photovoltaic Cells, novel plastics, devices for electrical interconnection, gels for medical applications, photovoltaics composites for vehicles, bio-compactible materials for implants and prosthetics, pharmaceuticals, films with special dielectric and many others. Some chemical engineers also work on biological research such as understanding biopolymers (proteins) and mapping the human genome.

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Chemical engineers have by tradition adopted their integrated approach to problem-solving skills in developing useful materials. They have applied their specialized knowledge in chemistry, transport phenomena, chemical kinetics, thermodynamics and reactor design to the study of dynamic systems and processes. They applied these principles to particulate systems. The primary challenge of chemical engineering science is the understanding of the structure, rheology, interfacial and transport behaviors of complex fluids and polymers. Chemical engineers are hence addressing this challenge through analytical theory, numerical simulation and experiments that span length scales from nanometers to meters. They develop material structure-process-property relationship that guide industrial design of robust new materials platforms. Chemical engineers apply principles of chemical engineering to transform physio-chemical and biological properties of materials or combined materials into useful or more useful purposes. For example, rapid (nanosecond) melt- and non-melt annealing of semiconductors and nanocrystals can create crystalline materials that control the diffusion of dopants and defects to produce nanostructures with characteristics unreachable by ordinary processing. A dopant (doping agent), is a trace impurity element that is introduced into a substance (in very low concentrations) to alter the electrical or optical properties of the substance. Non-crystalline substances such as glass, for instance, can be doped with impurities. An understanding of the phenomena that define metastable states an atom, nucleus, or other system: kinetics and thermodynamics, as well as mass, momentum, and heat transfer makes the chemical engineering discipline key to materials development. A body or system in metastable state exists at an energy level (metastable state) above that of a more stable state and only requires the addition of a small amount of energy to induce a transition to the more stable state. Furthermore, the success of new technologies such as laser processing and atomic layer deposition builds on the chemical engineer’s integrated understanding of fundamental physical and chemical materials properties. Much of the research carried out in these areas has direct applications in: • Processing and design of next-generation cyber electronic materials for logic gates, memory, and interconnects. • Design, fabrication and device integration of nanoscale building blocks for solar cells and batteries. • Organic and inorganic materials for solid-state lighting, computer displays and LEDs.

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Physical and chemical properties of materials are not the same, hence the reason materials appear different from others. These properties are used to check for materials utilization. Some of the properties include • • • • • • •

Tensile Strength, Electrical properties, Thermal properties, Plastic properties, Magnetic properties, Flexibility or rigidity, and Resistance to damage.

3.6.1 Biomaterials Chemical engineering expertise is also applied in the design and development of biomaterials for implants and prosthetic, materials for dialysis membranes used in artificial kidney machines and so on. Many different synthetic and reformed natural materials are used in biomaterials and some understanding of the divergent properties of these materials is vital. University of Washington Engineered Biomaterials defined biomaterials as materials (synthetic and natural; solid and sometimes liquid) that are used in medical devices or in contact with biological systems. Biomaterials can be polymers, metals, ceramics, glasses, carbons, and mixture of materials. They are used as fibers, films, foams, coatings, fabrics and molded or machined parts. These materials are used to produce biocompatible materials and devices to repair or reinforce existing veins and arteries; to make stents used to facilitate drainage and reinforce weak arterial tissue; to make spinal, cardiovascular, and ophthalmic implant devices; to make artificial knees and hips, artificial hearts, breast implants and others.

3.6.2 Plastics Materials In petrochemical industries, chemical engineers also known as petrochemical engineers, research and develop new polymeric materials with important electrical, optical or mechanical properties. As a result of the development of the plastic ‘Bakelite’ in 1908, chemical engineers went on to develop the commercially viable mass production of polymers during the early twentieth century. Plastics are extensively prevalent materials because of the many desirable characteristics they possess, such as • Processing flexibility, • Broad resistance to chemicals,

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Figure 3.6.1 Plastic Product.

Nowadays plastics are used in making electric insulation, clothing, plugs & sockets, iron cooking handles, fashionable jewelry, children’s toys, computers, beverage bottles, television sets, packaging materials, clock bases, the specialized plastic used in lightweight bulletproof vests and so on. These and many more are the uses of plastics, notwithstanding its use in manufacturing industrial equipment such as automotive parts, industrial machine components, biomedical implants, athletic shoes, carpeting, insecticides, pharmaceuticals and medical instruments. The problem of plastics, however, is their non-biodegradable nature, which pose environmental hazards. Chemical engineering research as a result is also focusing on finding ways of producing biodegradable plastics from such renewable raw materials as soybeans, corn, and other agricultural and forest crops.

3.6.3 Telecommunications Materials Chemical engineers actively supported researches and innovations in telecommunication by commercially creating fiber-optic cables. These cables are used to transmit light signals for real-time telecommunications and digital data transfer across cities and states, making the modern communications we enjoy today to be possible. Consequently, development of instantaneous, worldwide voice, video, and data-transmission systems can be possible. Each fiber-optic is narrower when compared with human hair.

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Drawing glass into small-diameter fibers is a straightforward process but the thin glass fibers produced are very brittle and fracture easily. Chemical engineers therefore developed modified chemical vapor deposition process (MCVD) applied in coating the drawn glass fibers with a specialized polymer. This coating sustains the optical properties needed to guide light and data through the fibers, and even more importantly, prevents the fibers from fracturing, notwithstanding how severely bent they are.

3.6.4 Computer Chips Materials This has been discussed under chemical engineers in the electronic sector section. Key chemical engineering know-how being applied in this sector are: • Polymer science – in the development of patterned photoresist coatings; • Kinetics and thermodynamics - in the crystallization of silicon wafers; • Energy transfer – to maintain desired temperatures and manage heat buildup during the chip-making process; • Mass transfer – to improve impression of complex semiconductor-chip patterns and the plating of electronic microchannels.

3.6.5 New Researches New researches are ongoing in the field of material science. Chemical engineers are also inventing technologies to be used in bringing the discovered materials to reality. More efficient solar cell materials need to be developed in the quest for sustainable clean energy. The market growth of solar cells is about 25% per year worldwide, although shortage of silicon supply is impacting the growth of the market. Currently, spherical silicon solar cells design strategy and development of spherical silicon solar cell with semi-concentration reflector system comprising silicon balls of 1  mm diameter and reflective mirrors have been realized in Japan. Novel deposition method of anti-reflective coating for spherical silicon solar cells of 11% for a given area is a little lower than the 13% of current crystal Si solar cells; the amount of Si used can be reduced. Consequently, this can mitigate the silicon shortage issue. The yield of silicon balls with high crystallinity was a concept that was realized by chemical engineers.

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Examples of future materials and devices include single-walled carbon nanotubes (SWNT) and spherical silicon solar cells (SSSC) with a semi-concentration reflector system. Chemical engineers are also pioneering significant advances in new materials that exhibit ultralight weight, improved structural strength, wear resistance, thermal conductivity, and superior mechanical properties. Israeli researchers have worked on pilot-scale production of a new high-temperature thermal ceramic insulator that may become a safe and economical substitute for asbestos and other potentially harmful ceramic fibers now in use. The new material is ceramic foam that contains 94% to 96% air by volume, but can resist temperatures above 1700°C. It is being developed under the direction of chemical engineering professor Gideon Grader at the Technion-Israel Institute of Technology in Haifa. Prof. Grader established a new company, Cellaris, at the Technion’s Entrepreneurial Incubator Company to produce the foam [43]. Chemical engineers are leading the development of nanomaterials. To produce highly efficient devices at low cost, the shape and nanostructure of materials must be controlled. This can be achieved by applying chemical reaction engineering principles to design efficient devices by controlling the shape and nanostructure of materials. Procedure to structure knowledge for profound understanding of the relationships among processes, nanostructures, and functions can be provided by chemical engineering. This is achieved by explaining the mechanisms of nanostructure formation, such as clustering, nucleation, and microphase separation that arise in several types of material fabrication processes.

3.7 Space Program Chemical engineers in the space program are involved with materials, chemicals and processes for the space program. A rocket engine is a chemical engineering process. Propellants are pumped, chemical reactions occur and a lot of heat energy is released. Much of chemical process design involves managing heat and of course materials. FLUENT, a computer program developed by the chemical engineering department at Sheffield University is a computational fluid dynamic package (CFD) used in tackling problems associated with aerodynamics, heat transfer, fluid flow and thermal combustion. Chemical engineers, in addition to providing support to processes and control systems in rocket engines, also utilize their expertise in managing safety and minimizing pollution.

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The testing and characterization of propellants; the flow behavior of propellant slurries (rheology), are the work of chemical engineers in this sector. In order words, characterizing flow behavior and mechanical properties of propellant; project management; quality management of composite materials and structures; composites process control and characterization are the major roles of chemical engineers in the space program. Composites are essential structural materials used widely in launch vehicles and spacecraft because of their lightweight and high strength-to-weight ratio.

Figure 3.7.1 Rocket Powered by Propellants (Image available at: https://ichemepresident. files.wordpress.com/2014/09/space-shuttle.jpg, 2016).

Chemical engineers have developed high-performance materials with superior properties that allow for successful performance under increasingly strenuous operating conditions. These materials were initially created to respond to the challenges of space travel and are having applications in other areas. Many impressive advances have been made using materials from each of the major material classes—plastics, ceramics, and metals in modern inventions. Demanding conditions in risky environments required the use of ever-more advanced materials. New ways of manipulating chemistry and internal structures had to be devised in order to create materials able to survive in • Very hot or cold temperatures, • Sternly corrosive environments, and

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Also, advanced metal alloys based on magnesium, aluminum, and titanium, which provide greater structural strength at reduced weight, are used for aircraft and spacecraft applications.

3.8 The Environment Segment Chemical engineers develop processes (catalytic converters, hydrotreatment, effluent treatment facilities) to minimize the release of or deactivate products harmful to the environment. Holly Lynch in his practicum, “A chemical engineer’s guide to environmental law and regulation, 1994”, states that environmental laws require chemical engineers to perform affirmative duties and, if those duties are not performed, chemical engineers and the firms for which they work may be held civilly and/or criminally liable. Thus, chemical engineers are constantly devising new ways of treating or recovering waste products from chemical production plants. They are more involved in systems analysis, process modeling of pollutants, and design of processes, from first principle, to tackle environmental hazards and or treat anticipated industrial waste (solid, liquid or gases). Over the years they have acquired remarkable skill that is being applied to control natural or man-made environmental pollution. These technologies are found in effluent water treatment processes, waste to gas processes, green technologies and others.

Figure 3.8.1 The Environment.

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Chemical engineers are currently solving the problem of industrial environmental pollution through product design (a process where design focuses on the product), process improvement (where design focuses on eliminating unwanted by-products and hazardous pollutants. They have developed many “end-of-pipe” control technologies to capture and destroy hazardous pollutants produced by industrial processes. Effort to eliminate the formation of pollutants early on in the production process was started by chemical engineers in the 1980s.

Source Reduction

Recycling

Treatment

Ultimate Disposal

Figure 3.8.2 Pollution Prevention hierarchy in order of decreasing preference. Source: Perry’s Chemical Engineer’s Handbook, pp. 25-14 [44].

Elements in the above Figure 3.8.2 are used by industry in combination to achieve the greatest waste reduction. Chemical engineers are also in the forefront of sustainability energy development, which will replace energy from fossil fuel in the future—a way of making our environment safer. They are also working to reduce greenhouse gases in the atmosphere. The term greenhouse gas, or GHG, refers to a gas that has high heat-trapping potential in the atmosphere. The ability to trap heat is why GHGs are adjudged to be the cause of global warming. The six main GHGs are • • • • • •

Hydrofluorocarbons (HFCs), Sulfur hexafluoride (SF6). Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), and Perfluorocarbons (PFCs).

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GHG emissions are produced primarily because of: • Energy combustion from electric generators, steam, and heat generators; • Energy combustion from land, air and sea transport mechanisms such as cars, trucks, buses, train, airplanes; and • Physical and chemical processing operations. Current projects aimed at developing technologies to tackle CO2 emissions include: • Pollution-control systems engineered to capture CO2 emissions; • Advanced combustion systems that reduce the formation of CO2 and other combustion-related GHGs; • Use of cleaner-burning alternative energy sources, such as biomass-derived fuels and solar- and wind-generated power; • Development of mechanisms for sequestering (isolating) CO2 emissions underground to prevent their accumulation in the atmosphere (not yet practiced on a commercial scale), and others.

3.8.1 Green Engineering Chemical engineering discipline plays a major role in green engineering, although green engineering cuts across all design disciplines. Mendez (2007) [45], has provided a green-engineering checklist that chemical engineers can apply to evaluate options that support a green-engineering goal in designing a new plant: • Design energy-efficient plant during conceptual stage because typically 98% of operating costs and 80% of capital costs are committed during front end engineering design (FEED); • Harness opportunities to apply low energy separation technologies, such as membrane separation, adsorption, and pervaporation separation; • Plan materials of construction for higher process temperatures and applicable, ancillary energy-recovery equipment from small scale to large scale;

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• Identify the best location for a new plant – locations that reduce transportation costs and inventories, using supply chain technologies and services; • Check designs that are safer for workers and environmentally benign even if slightly less profitable; • Balance the trade-off between capital and energy costs – capital is one-off expenditure while energy utility will be a recurrent expenditure; • Consider alternative energy utilization and green materials as your products; • Consider recycling waste heat; • Apply advanced controls and online optimization – proven technologies that can help save large quantities of energy and raw materials; • Perform complex-wide optimization.

3.9 Summary of Industry Segments Served by Chemical Engineers The focus of companies in these industries is on the development, extraction, isolation, combination, and use of chemicals and chemical by-products. Chemical engineers design and operate processes and systems to combine, transport, separate, handle, recycle, and store them. The industries consist of several specialty and sub-specialty areas:

Table 3.9.1a Summary of Industry Segments Served by Chemical Engineers. Specialty Areas

Sub-specialty Areas

Base Chemicals - Chemicals, including Petrochemicals (Batch, Continuous, Commodity, Specialty)

Petrochemicals, industrial gases, man-made fibers, industrial organic and inorganic chemicals, alkalis and chlorine, gum and wood chemicals, synthetic rubber (vulcanizable elastomers) and other chemical preparations

Fertilizers and Agricultural Chemicals

Fertilizers (nitrogenous), phosphatic fertilizers, agricultural chemicals (Continued)

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Table 3.9.1a Summary of Industry Segments Served by Chemical Engineers. (Continued) Specialty Areas

Sub-specialty Areas

Specialty and Fine Chemicals

Personal care ingredients, dyes and pigments, leather chemicals, dyes, paints, inks, elastomers, adhesives, photographic chemicals, mining chemicals and other chemicals

Biochemicals

Bio-agriculture, bio-pharmaceutical, and bio-industrial products

Pesticides, Fertilizers and Other Agrochemicals

Fungicides, insecticides, herbicides, weedicides, rodenticides, fumigants and other crop protection chemicals

Organic and Inorganic Chemicals

Organic - acetic acid, acetone, nitrobenzene, acetone. Inorganic - caustic, chlorine, sulphuric acid, caustic soda, potassium chloride etc.

Drugs and Pharmaceuticals

Antiseptics, antimalarial drugs, trentyxicyls, antipyretics, analgesics, medicinal chemicals and botanicals, cosmetics, perfumes, soap, detergents, specialty cleaning, polishing, and sanitation preparations, body cleansing oils, surface active agents, finishing agents and biological products

Plastics and Petrochemicals

Ethylene, benzene, propylene, xylene, polymers

Dying and Tanning Products

Pigments and pigment-like materials, inks, synthetic dyestuffs

Fatty Substances, Camphor, Chars and Carbons, Waxes Synthetic Resins, Materials, Rubber, Plastic Materials

Nylon, PVC, electronics, toys, electrical materials, rubber footwear, tires and inner tubes, fabricated rubber products, synthetic resins, composites, nuclear material processing

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Table 3.9.1b Summary of Industry Segments Served by Chemical Engineers. Specialty Areas

Sub-specialty Areas

Lime, Marble and Cement

Calcium oxide (lime), cement, marble

Metals and Minerals Processing

Primary and secondary smelting and refining of lead, aluminum, zinc and copper, electrometallurgical products, alloying of nonferrous metals and alloys, electroplating, polishing, plating, anodizing, coating, solder, rare earth metals - high refractive index glass, e.g. camera lens, rare earth magnets, lasers, x-ray tube, computer memory chips

Fats and Oil

Vegetable oils, soybean oil mills, cottonseed oil mills, margarines, butter, marine fats and oil and other edible fats

Foods, Beverages and Flavor Extracts

Industrial food packaging chemicals, Coffee, wet corn milling, evaporated and condensed milk, starch, cane sugar, malt beverages, wines, brandy spirits, rectified, distilled and blended liquors, essential oils, vegetable oils, vinegar flavoring extracts, salts, fruit flavors, essences, esters, perfumes

Explosives and Ammunition

Small arms ammunition, explosives, ordinance and accessories

Wood

Paper, charcoal, pulp mills, paper coating and glazing, building board mills

Glass, Stone, Clay and Ceramics

Clay refractories, abrasive products, gypsum products, flat glass, brick and structural clay tile, glass containers, glass fibers, mineral wool, nonclay refractories, asbestos products, glassware, nonmetallic mineral products, pottery products

Biofuels

Ethanol, biodiesel

Man-made Fibers

Cellulosic man-made fibers, synthetic organic fibers

Petroleum oilfields Chemicals

Drilling fluid chemicals, cementing chemicals, workover and completion fluid chemicals, simulation/production chemicals, enhanced oil recovery chemicals, corrosion inhibitors, treatment chemicals, filtration control agents, lubricants, deformers/antifoams

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Table 3.9c Summary of Industry Segments Served by Chemical Engineers. Specialty Areas

Sub-specialty Areas

Petroleum Refining and Coal Products (Upstream Oil and Gas Processing)

Crude oil, hydrocarbon gas, gasoline, asphalt felts and coatings, lubricating oils and greases, carbon black, coke and by-products, coke ovens

Leather Tanning and Finishing Paints, Varnishes, Pigments and Allied Products

Inorganic pigments, paints, lacquers, enamels, varnishes and allied products

Others

Carbon and graphite products, storage batteries, lead pencils, crayons and artists painting materials, semiconductors, coated fabrics, finishers of broad woven fabrics, artificial silk, surface floor covering, polishes, photographic film and chemicals

4 Career Diversities in Chemical Engineering 4.1 Introduction There is a range of possibilities inside the field of chemical engineering; this is in addition to the demand outside the engineering field. Many chemical engineering graduates choose a specific career path, develop an area of expertise, or serve a single purpose on a team. Graduates can specialize in a wide range of areas such as design, process & plant management (as process engineers), project engineering/engineering management, environmental engineering, safety engineering, automation & process control, quality, validation, and so on. Areas chemical engineering skills needed are as wide and varied as the field of chemical engineering. Some of the graduates will work in chemical, petrochemical or biochemical or biomedical or material science laboratories doing research and development or quality engineering; at field locations planning, supervising and managing the construction, commissioning, startup and or decommissioning of manufacturing plants; on production floors planning, supervising and troubleshooting and improving operations, in municipalities doing technical sales, service and consultancies; at computer terminals designing processes and products and control systems; in government agencies responsible for environmental and occupational health and safety; in hospitals and the health sector practicing biomedical engineering; in law firms specializing in chemical process-related patent work; in executive offices performing technical administrative functions; and in classrooms teaching chemical engineering undergraduate and graduate students.

4.2 Career Development Leading to Specialization The dynamic nature of the field means the chemical engineering graduate in an industry can expect to be offered significant continuing professional Uche Nnaji (ed.) Introduction to Chemical Engineering: For Chemical Engineers and Students, (115–164) © 2019 Scrivener Publishing LLC

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development (CPD) opportunities in order to develop new knowledge. The nature of the role of a chemical engineer leads to the creation of versatile, multiskilled professionals capable of handling a wide range of technical, environmental and commercial challenges. Chemical engineering graduates may begin their careers on a graduate training scheme, which may last two years. Following this, they may move on to manage their own projects, or work as assistant chemical engineers. On completion of a training program, the trained engineer may progress from primarily technical roles, through the promotion structure, to highly regarded and well-paid senior technical appointments. The engineer growing in experience and passing through these work challenges may also ultimately rise to senior management positions as director of functions or higher. Initially, however, graduates will gain experience of a range of projects, either within the same company or, after gaining chartership (that is, engineering regulatory bodies of their respective countries) and/or by changing companies. After training in the early years, there are various possible career routes: • To continue working on projects where they can rise to project managers or directors; • To develop expertise in a new technique or process in demand within the industry and move into research and development; • To move into specialist roles, such as safety, quality and risk management, project engineering or environmental management; • To move into commercial areas, such as technical sales, procurement, intellectual property, logistics and aftersales management, marketing, supply chain management, recruitment, finance and IT; • To opt for leadership roles, with opportunities to influence strategy and growth. Senior roles can include asset team leadership, business planning and analysis, non-operated joint ventures (NOJV), asset management, operations supervising and management, environmental, safety, fire, and health, and project management. Professional qualifications and continuous training are an integral part of career development, and there may be opportunities to move into other areas of engineering industry to gain new skills and experience.

Career Diversities in Chemical Engineering 117 Summarily, a practicing chemical engineer is engaged in one or more of the following activities:

1

• Undertakes research and develops or improves processes to achieve physical and/or chemical change for oil, gas, chemical, petrochemical, biochemical, pharmaceutical, paper and pulp, synthetic, food and other products.

2

• Designs, plans, test methods, supervises, controls, constructs and commisions chemical processing, associated plants and equipment, to refine, blend, generate products or recover and treat by-products. • Ensures that production methods, materials, quality standards and waste products or emissions conform to design specifications, safety requirements and environmental standards.

3

• Manages the safe and efficient operation, maintenance , modification and control of processing plant.

4

• Conducts economic, technical feasibility studies and costing for major investments in chemical and gas processing facilities for increased capacity and novel product manufacture.

5

Process Others Engineer Corrosion Engineer

Biochemical Engineer Pharmaceutical Engineer Process Control Engineer

Commissioning Engineer

Facility Engineer

Process Maintenance Engineer Sales Engineer

Planning Engineer

Chemical Engineering Career Options

Site Engineer

Refinery Engineer Process Safety Engineer

Piping Engineer Chemical Development Engineer

Quality Engineer

Biomedical Engineer Environment Engineer

Production Engineer Cost R&D Engineer Engineer

Figure 4.2.1 Chemical engineering career options.

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4.3 Chemical Engineering Job Titles/Options Chemical engineering job options discussed here are those career areas that can be directly or indirectly classified under any, some, or the entire foregoing activities: 1, 2, 3, 4, & 5. The options include:

4.3.1 Biochemical Engineer [1, 2, 3, 4, 5] This field studies the chemical processes occurring naturally in plants and animals. There is an increasing importance of biology and biochemistry to chemical engineering. The engineer here applies basic chemical engineering principles to biochemical and biological process industries such as enzyme technology, fermentation, and biological waste treatment. He or she understands relevant microbiology, biochemistry, and molecular genetics. Design and analysis of biological/biochemical process (including equipment such as reactors) and product recovery operations, is the domain of chemical engineers in this specialty. Utility companies employ biochemical engineers where they perform the work of examining ways to dispose of waste more efficiently while delivering supplies of clean drinking water to challenging areas. Figure 4.3.1 shows a biodiesel plant; the clumsiness of the plant can be seen; that is, when compared to conventional petroleum refinery that produces diesel from fossil fuel.

Figure 4.3.1 Picture of a Biodiesel Plant (Available at: http://www.filtsep.com/ view/16678/energy-materials-processing-filtration-and-the-fuels-of-the-future/, 2014).

Biochemical engineers apply chemical engineering principles to biological materials, processes and systems to create new products. These may include potable water, vaccines, biofuels, foods, plastic forks and

Career Diversities in Chemical Engineering 119 plates, cattle feed, fizzy drink sweeteners, clothing, soda pop sweeteners— the list is endless. They are also working in processes that may dramatically improve human lives. They are involved, for example, in developing and producing pharmaceuticals to reduce heart disease; making ‘magic bullets’ that locate and kill cancerous tumors; and synthesizing highperformance lubricants which last a car’s lifetime. They also develop processes to reduce pollution or treat waste products and convert them to useful products. Typical work activities include: • Designing, installing or constructing, and commissioning new production units, monitoring development and troubleshooting existing processes; • Finding ways or processes of producing cost-effective biofuels in commercial quantity; • Applying biological and biochemical principles to the mass production of new products; • Scaling up proven production processes so that the product can be manufactured in bulk, safely, economically and profitably; • Working with biochemists, chemists, biologists and others, to devise new products and processes. • Biochemical engineers may also function as part of management team for a biochemical project. • They can also specialize in particular processes or techniques. • An increasing number of graduates are choosing to join small start-up companies working on new biochemical technologies. Typical employers come from all sectors of the biotechnology industries, including those with interests in pharmaceuticals, food, biogas, environment, waste treatment, and consulting.

4.3.2 Chemical and Process Engineers (Design Engineers) [1, 2, 3, 4, 5] Job description Chemical and Process engineers are responsible for converting materials through unit processes (such as combination, separation, reaction, nitration, oxidation, polymerization and so on) into useful and valuable products. They design and scale up processes from laboratory, including food and drink, fuel, artificial fibers, pharmaceuticals, chemicals, plastics, toiletries, energy, and clean water. On the existing processes of converting raw materials into

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useful and valuable product, chemical and process engineers examine ways to improve the efficiency and economics of these processes. Chemical and process engineers work in a multivariate environment: cracking crude oil into useful products and by-products; working on oil sands projects that separate bitumen from sand (shale oil) and upgrade it to synthetic crude oil; applying technical know-how to improve production and water treatment at steamassisted gravity drainage (SAGD) plants; finding and developing new ways to remove moisture, contaminants, hydrogen sulphide and carbon dioxide from natural gas or reduce corrosion on equipment and pipelines, are just a few examples of the scope of the work of chemical and process engineers. Process engineers may work in small, midsize and large businesses. Responsibilities involve designing equipment, understanding the reactions taking place, installing and commissioning control systems, starting, running and upgrading the processes; and also performing process optimization studies and developing new designs. Environmental protection and health and safety aspects are also significant concerns for this engineer in performing his work. In a typical industry, a chemical process engineer will be saddled with the task of establishing fundamental heat and material balances, developing working process flow sheets, and transforming flow sheets into piping and instrumentation diagrams (P&IDs). The process engineer also takes care of sizing the various process equipment and materials of construction. The various equipment include pressure vessels, reactors, distillation columns, heat exchangers, crystallizers, piping, and incinerators. This job involves close interactions with experts in chemistry, materials, mechanical, civil, electrical and instrumentation engineering, and so on.

Figure 4.3.2 Mini Refinery is designed by chemical process engineers (Image available at: Proxion Mini Refineries, http://www.proxionminirefineries.com/products/, 2014).

Career Diversities in Chemical Engineering 121 Typical work activities Chemical and process engineering work is usually project oriented, and the engineer may be working on a number of projects, all at various different stages, at any given time. Several process engineering companies act as consultancies. An experienced process engineer can thus register and open a private consultancy firm. Typical work activities include: • Designing the conversion of small-scale processes into commercially viable large-scale operations; • Designing, installing, commissioning and operating new production units, monitoring modifications and upgrades, and troubleshooting existing processes; • Assessing processes for their relevance, and assessing the adequacy of engineering equipment, and analyzing technical health and safety risks and recommending options; • Reviewing existing process data to see if more research and information need to be collated; • Applying the principles of mass, momentum and heat transfer to process and equipment design, including conceptual, front end and detail design; • Ensuring that a process works at the optimum level, to the right rate and quality of output, to meet supply needs and satisfy customer; • Conducting process development experiments in a chemical engineering laboratory; • Assessing the availability of raw materials and the safety and environmental impact of a plant; • Managing the cost and time constraints of projects; • Assuming responsibility for risk assessment, including hazard and operability (HAZOP) studies, for the health and safety of both plant workers and the wider community; • Monitoring and improving the efficiency, yield and safety of a plant; • Assuming responsibility for environmental monitoring and current performance of processes and process plant; • Working closely with other specialists, including scientists responsible for the quality control of raw materials, intermediates and finished products; engineers responsible for plant construction and maintenance; commercial colleagues on product specifications and production schedules;

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The engineering process design team in an organization performs the following activities during the several engineering phases (see details in Chapter 5): • • • • • • • • • • •

Basic process design Technology/process selection Process Design Package Mass balance, energy and utilities balance optimization Integration of a unit in the overall upgrader’s scheme PFD design and review Equipment datasheet P&ID design and review Relief study and risk assessment study Mechanical review Metallurgy review

Career Diversities in Chemical Engineering 123 • Instrumentation and electrical engineering • Operating manual and procedure development, and so on.

4.3.3 Refinery Engineer [1, 2, 3, 4, 5] Refinery engineers design complex refining processes and work to ensure that quality, quantity and safety are maintained at a refinery. They are analytical, creative and innovative thinkers with excellent problem-solving skills. There are five general steps in the refinery process which include distillation, catalytic reforming, alkylation, catalytic cracking and hydroprocessing. These are identified as process units. Using refining engineering techniques, these engineers can develop products or raw materials for making products used in packaging many of the foods we eat and the clothes we wear, and which also help power our cars and heat our homes. Refining engineers usually work with a team of chemists and other scientists. They extract existing data and design methods to design better refined products and operate specifications for industrial plants. While conducting research and performing experiments, cost, safety and environmental impacts are considered by the engineers. They create engineering plans and process using computer software programs, which simulate activity and process models; hence, they test and predict possible errors and problems with a process, thereby generating workable solutions. Research and development (R&D) is a strong department in a refinery. Refinery engineers, therefore, are required to constantly update their skills and knowledge to keep up with technological advancements in this rapidly changing field.

Figure 4.3.3 Refinery engineers work in a petroleum refinery (Available at: http://leadership. ng/wp-content/uploads/2013/11/refinery_02-300x220.jpg, 2014).

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Typical work activities All refineries perform different functions, hence the job of the engineer will vary accordingly. A typical day for a refinery engineer will be working in an office, refinery, industrial plant or laboratory. Engineers who work in an alkylation production unit may encounter hazardous chemicals on a regular basis, hence caution and serious safety procedures are commonly observed. The typical work activities are: • Design, maintenance and management of petrochemical and petroleum processing plants; • Design and operation of quality and environmental control systems; • Troubleshooting environmental problems in industrial processing and manufacturing plants; • Ensuring efficient, safe and environmentally responsible plant operations; • Supervising technologists, technicians and other engineers engaged in support activities; • Choosing the best instruments for measuring pressure, temperature, flow rate and composition; • Advising management regarding the layout of industrial plants and the installation and sizing of equipment; • Determining the most effective processes for commercial production; • Conducting economic evaluation of projects to find the most cost-effective options; • Design and development of new and better processes and equipment for converting raw materials into products using computers to simulate, model and control such processes.

4.3.4 Chemical Development Engineer [1, 2, 3, 4, 5] Job description A chemical engineer is involved in design, development and implementation of systems and industrial processes for the production of a diverse range of products, as well as in commodity and specialty chemicals. They design specialist equipment and industrial processes which are safe for workers and for the environment and monitor efficiency of systems with tests, modifying them to increase yield or productivity. Basically, these careers are all about applying chemical engineering processes and principles for the development of new products and materials.

Career Diversities in Chemical Engineering 125 However, these careers may also involve modifying and upgrading existing products. The role may focus on one or more of the following: researching new products from trial through to commercialization; managing scale-up processes from plant to full industrial-scale manufacturing; improving product lines; modifying the processing plant that produces the products; and designing and commissioning new plants. Typical work activities Typical activities are extremely diverse, depending on the role, but may include: • Designing, evaluating, monitoring and developing chemical equipment and processes; • Analyzing and ensuring systems are safe to use and as environmentally friendly as possible; • Working closely with process chemists and control engineers to ensure the process plant is set up to provide optimum yield and efficient running of the production facility; • Designing plant and equipment configuration so that they can be readily adapted to suit the product range and the process technologies involved, taking environmental and economic aspects into consideration;  • Establishing scale-up and scale-down processes including appropriate changes to equipment design and configuration; • Evaluating options for plant expansion or reconfiguration by developing and testing process simulation models; • Designing, installing and commissioning new production plants, including monitoring developments and troubleshooting; • Evaluating costs and preparing financial reports; • Optimizing production by analyzing processes and compiling de-bottleneck studies; • Ensuring that potential safety issues related to the project operator, the environment, the process and the product are considered at all stages; • Developing novel technologies. Examples of work activities in specific sectors include: • Developing new ways of safe nuclear energy production, including projects such as conceptual design, computer

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4.3.5 Commissioning Engineer [1,2, 3, 4] Job description Commissioning is the process of planning, documenting, scheduling, testing, adjusting, verifying, and training to provide a facility that operates as a fully functional system with respect to the owner’s project requirements. When a chemical plant is fully constructed and ready for commissioning, chemical engineering personnel who specialized in plant commissioning would lead this phase. However, the commissioning engineer is required most times to be mobilized during the detail engineering phase of the plant construction for efficient and seamless commissioning. The earlier this engineer is involved in the project process the greater the chance there is for him or her to influence corrections without increased costs later. The objective of commissioning therefore is to ensure that the plant is brought into production without risk to the workers, the environment and the equipment constructed. The commissioning engineer is a chemical engineer with some design and operations experience. The commissioning engineer performs a technically oriented service function whenever construction of a part or the entire plant is said to be mechanically complete. The engineer here works with the operations supervisors during the operation. Commissioning activities include leak and pressure test; equipment inspection (towers, reactors, etc.); flushing, chemical and mechanical cleaning; temporary screens, strainers and blinds; purging and inerting; drying out; instrumentation verification, etc.

Figure 4.3.4 Fully Commissioned Chemical Plant (Picture sourced at: http://www.fluor. com/uk/projects/onshore-oil-gas-epcm-project-management, 2016).

Career Diversities in Chemical Engineering 127 Typical work activities • Issuing guidelines for planned task. The customer personnel can utilize these guidelines to develop the daily orders; • Participating in the review of P&IDs and control methods in view of start-up and safe operation of gas plants; • Responsible for the preparation and approval of the initial start-up program, checking the readiness and statement of fitness of the plant; • Ensuring that site processes are monitored and controlled to achieve safe, timely and economical operation while developing all customer personnel to their full potential; • Reviewing and commenting on operating manuals and start-up procedures; • Ensuring mechanical completion punch list items are closed; • Responsible for implementation of flawless project delivery associated with commissioning; • Providing technical leadership and expertise to facilitate safe, reliable, and economical operation of the site processes; • Responsible for coordination and mobilization of specialist vendor personnel as required; • Liaising between operating company and technology licensee. A commissioning engineer can grow to become a commissioning manager. A very experienced commissioning engineer may have a strong background in some or more of the manufacturing of a wide variety of chemical process technologies and product categories including; cryogenic liquids, benzene, ethylene, propylene, and toluene extraction, styrene, catalytic cracking, catalytic reforming, crude atmospheric and vacuum fractionation, polyvinyl chloride, wax blending/emulsion manufacture, coal gasification, Gas to Liquids/Chemicals, ceramics, adhesives, nuclear plant operation, steam and power plant operations and so on.

4.3.6 Maintenance Engineer/Maintenance Planning Engineer/ Process Maintenance Engineer [2, 3, 4, 5] Job description Process maintenance engineers plan the routine maintenance of a chemical or process plant and plant equipment. They work on-site or remotely diagnosing, forecasting faults and planning, overseeing and scheduling time-critical repairs and shutdown activities. Maintenance planning

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engineers plan, schedule and monitor shutdown maintenance activities in a process plant. This discipline is highly technical and complex because the engineer is dealing with a process plant which is a continuous operation. Unnecessary shutdown can have economic consequences and impacts a plant’s profitability. The engineer works long hours and would have backto-back working all days and nights of the week.

Figure 4.3.5 Maintenance Process Engineers at Work (Picture sourced at: http://www.bp.com/ en/global/bp-careers/students-and-graduates/graduate-opportunities/engineering.html, 2017).

In today’s complex plants, maintenance engineers use sophisticated, computerized systems to schedule and track work. They may directly oversee the work of teams of maintenance personnel, such as fitters and technicians or indirectly through a plant’s workshop manager. Maintenance engineers may be involved in all stages of the chemical manufacturing process. In the construction phase, they work to incorporate efficient methods of maintaining new equipment or plant and may be involved in the installation and commissioning process—writing maintenance strategies to help with installation and commissioning guidelines. Through the production phase, they work to improve the useful life of equipment and machinery. Typical work activities Maintenance engineering plays a vital role in the efficiency, development and progress of processing industries. They work with other professionals, such as production systems engineers and production managers, to improve production facilities, reduce the incidence of costly breakdowns, downtimes and develop strategies to improve overall reliability and safety of plant, personnel and production processes.

Career Diversities in Chemical Engineering 129 High-risk industries, such as nuclear, petrochemical and petroleum refining, have well-developed reliability strategies. In traditional manufacturing, maintenance engineers promote the improvement of overall reliability, in addition to responding to breakdowns. Maintenance engineers may also be called upon to develop plant asset care policies, which  would require them to  liaise closely with suppliers, customers, other disciplines and senior management. In some organizations, the work involves practical, hands-on engineering, problem-solving, and supervising technical staff. Typical work activities • Designing maintenance methods, procedures and plans; • Planning and scheduling planned and unplanned maintenance work; • Diagnosing breakdown problems; • Controlling maintenance tools, stores and equipment; • Carrying out quality inspections on jobs; • Directing, instructing and supervising maintenance technicians and fitters; • Liaising with client departments and customers; • Coordinating and sourcing specialist procurement of fixtures, fittings or components; • Monitoring and controlling maintenance costs; • Writing maintenance strategies to help with installation and commissioning guidelines. Initial career development may be as a technical specialist. Progression is into various senior engineering functions, including plant management and project management. Also, opportunities exist to become a maintenance manager or operations manager, where the main responsibility is to motivate and manage technical staff and develop maintenance programs. There may also be opportunities for a maintenance engineer to rise from maintenance manager to an asset, technical and or operations manager position.

4.3.7 Process Control/Automation Engineer [2, 3, 4] Job description Process control, per Wikipedia, is an engineering discipline that deals with architectures, mechanism and algorithms for maintaining the yield of a

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specific process within a desired range. For example, the temperature of a chemical reactor may be controlled to maintain a steady product yield. Chemical engineers specializing in this area are required to master relevant complex computer programming languages. Process Automation Engineers design, develop, install, commission and oversee instrumentation and control systems that sense, measure, and run operational processes in a chemical or gas plant. Jobs vary from handling broad system projects to providing expertise on specific portions of process control. Process control and automation engineers oversee the quality-control portions of product development, such as temperature and liquid levels in processing tanks. Process control is extensively used in industry and enables mass production of continuous processes such as oil refining, paper manufacturing, gas plants, chemicals, power plants and many other industries. Process control enables system automation, with which a small staff of operating personnel can operate a complex process from a central control room located in the plant. The process control engineer should demonstrate proficiency in the development and management of process control solutions, from collecting data through the design, configuration, and integration processes. Besides technical knowledge and expertise, the process control engineering field, like other engineering, requires exemplary interpersonal relationship skills. The process control engineer would need to keep in touch with the emerging technologies and applications to guarantee a competitive edge in the industry.

Figure 4.3.6 Process Control Engineers (Image available at: The future of DCS, http:// www.flowcontrolnetwork.com/the-future-of-dcs/, 2017).

Career Diversities in Chemical Engineering 131 Typical work activities • Designing, engineering, testing and troubleshooting control systems; • Installing, commissioning field instruments; • Starting up a chemical plant; • Ensuring field devices, instrumentation systems, communication networks, data management and interfaces work properly; • Testing procedures preparation; • Development and implementation of engineering guidelines and standards; • Detailed documentation of the plant’s process control philosophy; • System Integration; • Interacting with field teams, consulting firms, contractors and vendors. Types of control systems are described in Section 1.6.

4.3.8 Process Safety Engineer [1,2, 3, 4,5] Job description Process safety engineers develop safety strategies, programs, processes and plans that ensure safe working conditions of a process plant (see Chapter 6 for details). Process safety engineers or safety engineers, in some cases, are different from HSE engineers. This is core engineering discipline. Specialists here work as part of process engineering team during the conceptual and detailed engineering design phase of process plant development. They carry out engineering designs. Health and safety professionals, on the other hand, provide healthy and safe environments for employees, contractors, and communities near company operations. A process safety engineer is primarily responsible for leading and supporting process safety management initiatives and operational safety initiatives. The engineering involves implementing into everyday engineering procedures a broad-based understanding of the complex interaction of chemical process technology, mechanical and process design, process control, and process safety management systems (PSMS); and by virtue of knowledge and experience, process safety engineers evaluate an integrated chemical

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Figure 4.3.7 A Complex Chemical Plant: Process Safety Engineers Ensure Its Safe Operation (sourced at: http://gymkhana.iitb.ac.in/~smp/chemical.html, 16).

and petrochemical process. They identify hazards: overpressure/under pressure, thermal expansion and brittle fracture, fire and explosion, static electricity, human factors, dust explosion, chemical and reactive chemistry hazards and toxic exposure hazards; and also evaluate the risk from those hazards, both qualitatively and quantitatively. In addition, they assist in the identification and evaluation of cost-effective engineering solutions to reduce or mitigate those risks: • Remove or reduce the hazard through inherently safer solutions • Simplify the process • Operate at less hazardous operating conditions • Reduce inventories • Reduce the likelihood of risks by providing more or better layers of protection • Reduce the consequence of risks by employing mitigating systems • Apply Human Factors principles to reduce the error potential at the interfaces of people with equipment and instrumentation To successfully perform these functions process safety engineers are knowledgeable in engineering standards and practices: legislation and regulations, process safety management systems, etc.

Career Diversities in Chemical Engineering 133 Furthermore, process safety engineers are responsible for organizing a hazard and operability study (HAZOP) during project execution. HAZOP is a structured and systematic examination of a planned or existing process or operation in order to identify and evaluate problems that may represent risks to personnel or equipment or prevent efficient operation. The HAZOP technique was initially developed to analyze chemical process systems but has later been extended to other types of systems and also to complex operations and to software systems. A HAZOP is a qualitative technique based on guide-words and is carried out by a multidisciplinary team (HAZOP team) during a set of meetings. Once the causes and effects of any potential hazards have been established, the system being studied can then be modified to improve its safety. The modified design must then be subject to another HAZOP, to ensure that no new problems have been added. (See Section 6.3.1 for detailed HAZOP techniques.) Typical work activities • Auditing key elements of process safety to ensure processes are being followed and are working as intended; • Confirming proper resolution and closure of recommendations from process safety studies, audits, and incident investigations; • Ensuring site personnel are trained and recognize their role in process safety; • Ensuring appropriate hazard analysis and risk assessments are performed on technical changes; • Communicating and working with management to ensure leadership and proper emphasis on process safety, including employee participation; • Developing operating & emergency response procedure; • Modeling chemical vapor atmospheric dispersion in a process industry; • Ensuring that projects fully address process safety in-design and satisfy process safety requirements; • Providing specialist consulting service in safety and fire protection in the design, engineering, construction and operation of chemical or gas plants and refineries; • Monitoring additions and changes to codes and standards applicable to company operations; • Assisting in the implementation and improvement of process safety management systems;

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4.3.9 Biomedical Engineer [2, 3, 4] Job Description Biomedical engineering is one of the growing fields of engineering which combines engineering principles with medical and biological sciences to design and create equipment, devices, computer systems and software used in healthcare. The devices and equipment used in hospitals and health care centers are inventions of biomedical engineering, including a simple sphygmomanometer that measures blood pressure and a pacemaker that regulates the heartbeat of a person. These help to solve the medical problems with the help of devices developed by them.

Figure 4.3.8 Biomedical engineer at work. (Image available at: http://www.buzzle.com/ articles/biomedical-engineer-salary.html, 2014).

Career Diversities in Chemical Engineering 135 Chemical engineering graduates who wish to specialize in this area will either choose a biological science elective or get a graduate degree in biomedical engineering. During the two-year graduate program in biomedical engineering, the graduate chemical engineer will be trained to work as a technological designer of high-tech instrumentation and equipment in the medical industry. He or she will also learn to measure, make models, design prototypes, quantify and analyze systems. Biomedical engineers are employed in the industry, universities, in hospitals, in research facilities of educational and medical institutions and in pharmaceutical companies. In industry, they may create designs where an in-depth understanding of living systems and of technology is essential. Some international companies that manufacture healthcare equipment include Philips Healthcare, Shell Global Solutions, and so on.

Figure 4.3.9 Biomedical engineers at work (Credit: Stan Ackermans Institute).

Typical Work Activities • As mentioned earlier, a biomedical engineer applies laws and principles of biology, medicine and engineering to develop devices that can be used for improving the health of a person or even for saving someone’s life; • They design and construct devices that can solve various medical and health problems; • They work for producing equipment that can comfort a patient suffering from a disease. Many of the diagnostic machines used for processes like Magnetic Resonance

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• • • •

4.3.10

Imaging (MRI), CT scans, X-rays, sonography, ultrasound, and so on are all inventions of biomedical engineering; They also work on development of artificial devices that perform functions of body organs like artificial limbs, pacemaker, kidney machines, etc. They mediate closely with doctors, therapists and customers and find solutions to their medical problems; They design, with the help of computer software, develop and construct new devices and equipment; The engineers research thoroughly to determine the effect of a medical device on the human body; Thus, we can say that they design and develop devices and equipment that can assist healthcare practitioners and can improve the quality of life.

Research & Development Engineer [1, 2, 3, 5]

Job description Chemical engineering involves research, where engineers develop and test new materials and processes or adapt and improve existing ones; and conduct process development experiments in a laboratory and convert these small-scale processes to commercially viable large-scale operations. Research and development engineers conduct the basic research and are also responsible for building experimental plants, pilot plants, testing the processes concerned, gathering design particulars, solving practical problems, to decide whether the project should be taken to full scale. The chemical processing industry is built on processes discovered and developed in the research and development laboratory. Chemical engineers are counted on to quickly identify viable research paths and how to scale small proofs into commercial operations. Research and development focus on varied fields such as waste treatment, paper manufacturing, technical sales and chemical plants, and so on. The general objective of a chemical engineer in this area is to transform laboratory processes into commercially viable operations that are safe, efficient, and ecologically sound. Such engineers invariably work at the pilot plant level. Chemical engineers working in R&D may work with chemists, biological scientists and other engineers to develop a new process or new product that will better meet customer needs. R&D engineers make new ideas come to life as the bridge between products and the consumer. They interact and understand the need of

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Figure 4.3.10 R&D engineers frequently work in research and development or in quality assurance (Picture sourced at: http://www.bls.gov/ooh/architecture-and-engineering/ biomedical-engineers.htm#tab-4, 2016).

consumers, then conceptualize products, processes & packaging that meet or exceed their needs. Research engineers can work in one of three areas in a typical chemical company: process development, products research, or packaging development. Products research engineers develop a strong understanding of consumer needs, establish formulation, create product/package specifications and quality measures, and monitor consumer feedback. Process development engineers develop novel processes to make useful products. They design and execute experiments at the bench and in pilot plants which eventually lead to scale-up at manufacturing sites. Package development engineers manage the design and material development of product packages. Focus is on innovative packaging that improves functional product performance, consumer acceptance, package shelf appearance and easy to use while supporting environmentally friendly packaging. Typical work activities: • Applying mathematical modeling to work out whether new developments and innovations would work and be cost effective; • Scaling-up from bench-scale to batch demonstration;

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Collecting and analyzing data from tests on prototypes; Modifying designs and retesting; Installation and calibration of on-line composition sensors; Off-line analytical techniques to assess product quality and interfacing with plant sites to define and standardize a critical quality laboratory procedure and documenting results in technical memos and in a plant presentation.

R&D engineers enjoy considerable variety in their work. A chemical engineer who works in the R&D laboratory says that in her work, she doesn’t believe there’s a usual project, and this she enjoys. The work can vary very much depending on the type of project and its development stage—for example, bench-top experimental work, production-scale trial batches, technical presentations, or report writing. She focuses on reaction engineering and describes her work as process or technology transfer—the transfer of new or improved chemical processes from the bench scale to commercial-scale equipment.

4.3.11

Sales Engineer [3, 5]

Job description Chemical engineers often work as sales engineers in big chemical processing industries. This is because they are in a better position to interpret and explain in detailed technical functions and specification of equipment being sold to specific customers. The use of a chemical engineer as a sales engineer in big chemical processing organizations offers an advantage over non-technical persons in that the engineer here can know what may be possible in terms of customer demands. Many products and services, especially those purchased by large companies and institutions, are highly complex. Sales engineers determine how products and services could be designed or modified to suit customers’ needs. They also may advise customers on how best to use the products or services provided. These engineers are also concerned with analyzing, developing, pricing, packaging, publicizing, and advertising in chemical processing companies. They possess extensive knowledge of chemical process equipment and products, including knowledge about their components, functions, or use and the scientific processes that make them work. Sales engineers generally use a “consultative” style; that is, they focus on the client’s problem and show how it can be solved or mitigated with their product or service. For this position one needs excellent people skills and a solid background in economics.

Career Diversities in Chemical Engineering 139 Typical work activities: The chemical engineer in this area is responsible for the development of sales on defined territory or customers: • Executes strategic and tactical sales plan to contribute to growth and profitability; • Visits his customers and prospects frequently; • Identifies and drives new and existing business opportunities by getting effective, timely and accurate customers information; • Collects requests for quotation, providing and following-up offers; negotiating and concluding sales business; • Develops durable relationships with customers or clients; • Works with customers to understand market demands, technical and quality requirements, pricing considerations, and impact of new applications and products; • Interfaces with and pulls together all functional areas to ensure customer needs are being addressed internally, influences engineering team, industrialization, production and support groups to optimize business growth, orders and profitability; • Sales administration, supervision and coordination; • Preparation of sales plan, and so on.

4.3.12

Performance Control Engineer [1, 2, 3, 4]

Job description The performance control engineer’s job involves specification, design, development, realization and testing of subsystems within the limits of system specifications, costs and project planning. The engineer here coordinates with other disciplines to ensure the timely realization of competitive, achievable products, including the product’s documentations. (See also planning engineer job title for more details.) Typical work activities Duties of an engineer in this specialty will include the following: • Maintaining and rolling out the technical integration plan to support plant operation management and optimization. This plan aims to support the operations team’s efforts to run just-in-time operations by enabling it to promptly spot and adjust any production-level drift;

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4.3.13

Planning Engineer [2, 3, 4, 5]

Job description Chemical engineering graduates are most suitable to work as planning engineers in a chemical process, oil, gas or refining companies—during the development of the facilities and management and operation of the facilities. Students who wish to specialize in this area should be well abreast with engineering management course. The planning engineer in collaboration with technical, construction, procurement and commissioning managers of an EPC company, creates and figures out how detailed engineering, procurement, construction and commissioning activities will take place in the most efficient, safe and economic manner without compromising quality. EPC here means engineering, procurement and construction. They gather information from cost estimators, buyers, quantity surveyors, vendors, specialist engineers and every other discipline to plan the execution of an EPC project. The planning engineer is thus responsible for specifying the timing, resource requirements of the various phases of a project, from conception, commercial phase to engineering, procurement, construction and commissioning phases and integrating required activities into a logical network plan. This plan is where the desired control mechanisms can be derived. This can be a major responsibility when penalty clauses for late completion are written into project contracts. The planning engineer utilizes process & instrumentation diagrams (P&IDs) and technical drawings of all disciplines during project construction. The more experienced at constructing and designing different facilities the better the planning engineer. In complex chemical process plant facility construction, the planning engineer normally will have full understanding of what is to be developed, the process description, all the process equipment to be installed (equipment sizes and weights), details of the scope of work, including where the plant is to be built, parameters that control the site, the site conditions, equipment needed to develop the project, manpower needed to construct it, the time it will take to order, long lead equipment items and materials for the project, and so on. Typical work activities • The planning engineer selects the appropriate techniques and sequence of events for a particular project;

Career Diversities in Chemical Engineering 141 • Analyses construction sites and local environments to determine appropriate logistics solutions and resources; • Draws up plans and presents schedules of work, often with visual aids such as bar charts and procedures diagrams; • Uses specialist planning computer software; • Prepares integrated plans and pricing schedules for individual projects; • Monitors progress throughout the construction process and comparing this with the baseline schedule; • Liaises with the site teams throughout the process, making adjustments to projects as necessary; • Provides advice and support on the development of specific systems; • Monitors budgeted costs against the actual costs being spent in the course of implementing a project; • Interfaces with every other specialists in the project.

4.3.14

Facilities Process/Plant Engineer [2, 3, 4, 5]

Job Description Facilities engineers analyze material and labor costs, review construction bids, review approved for construction drawings and make contractual recommendations. The facility engineer will most times oversee the ongoing operation of the various systems; he or she will specify the maintenance schedule of each operating system within the process plant. Responsibilities include project management of internal facility capital projects, development and oversight of plant construction programs. Work is project oriented and the engineer may be working on a number of projects, all at various different stages, at any given time. Several facility process engineering companies act as consultancies. Any engineering graduate from any of the engineering disciplines can train to become a facility engineer but when it concerns a chemical or gas plant, the chemical engineer will have a smooth ride on the job. Typical work activities • The facilities process engineer develops and manages preventive maintenance programs, including new preventive maintenance procedures, work review and approval; • Manages exception reporting, corrective action and change control activities; troubleshoots and performs root cause failure investigations;

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Introduction to Chemical Engineering • Provides technical support to facilities and other site departments as needed for repairs and process optimization; • Manages internal plant capital projects as assigned, including scope development, estimating, budget, scheduling, change control and project management of design, construction, commissioning and validation support; • Manages contractors and vendors as required; • Maintains facility design and engineering documentation; • Develops spare part requirements in conjunction with facilities personnel; • Administers environmental monitoring systems (EMS); • May serve as facilities project manager for the installation of new projects after gaining several experiences.

4.3.15

Pharmaceutical Engineer/Pharmaceutical Process Engineer [1, 2, 3, 4, 5]

Job description The discipline of Pharmaceutical engineering is a relatively new concept. It is a branch of pharmaceutical science and technology that involves development of processes for converting chemical and biological materials into valuable pharmaceutical products (drugs), and components in the pharmaceuticals industry and then manufacturing the pharmaceutical products. Shorter development times and a far more economical production of drugs have made pharmaceutical engineering into an economically relevant factor. The program emphasizes fundamental scientific, technical, and regulatory expertise. Developing pharmaceutical products involves many interrelated disciplines (e.g. medicinal chemists, biochemists, pharmacists, analytical chemists, clinicians/pharmacologists, chemical engineers, biomedical engineers, and so on. The dedicated subfield of “pharmaceutical engineering” has only emerged recently as a distinct engineering discipline. Institutions offering pharmaceutical engineering include Rutgers University (the first of its kind, initiated in 1994) which has an eightmodule pharmaceutical engineering track within its chemical engineering degree, and the University of Michigan, which awards a B.SE in Chemical Engineering/MEng in its Pharmaceutical Engineering program. Also, Chemical and Pharmaceutical engineering is offered as a joint program by Graz University of Technology and Karl Franzens-University, all in Austria (language of instruction is English). Others include the University of Manchester, which in 1995 started offering a postgraduate distance

Career Diversities in Chemical Engineering 143 learning masters in pharmaceutical engineering, Herriot Watt Edinburgh, which in 1998 created pharmaceutical engineering options/specializations, University of Leeds, University College Cork (in 2001), New Jersey Institute of Technology, University of Adelaide, Stevens Institute of Technology, New Jersey and Ecole Polytechnique-University of Montreal, and Royal Institute of Technology (KTH), Sweden. Faculty members can come from both colleges of engineering and pharmacy.

Figure 4.3.11 A Pharmaceutical Plant (Picture sourced at: http://www.gea.com/global/ en/index.jsp, 2017).

Pharmaceutical process engineers perform the design of pharmaceutical plants, developing user requirements, layouts, mass and energy balances, functional sizing of equipment, flow-sheets (P&ID), functional specifications, and so on, and also perform process coordination during design from conceptual design to plant commissioning and validation, etc. These engineers take the concepts of new drugs from the laboratory to the factory floor by discovering ways to scale these new inventions; keeping medicinal products within specified tolerances and quality control parameters. Pharmaceutical Engineers take small-scale drug formulation processes and upscale to industrial production without loss of effectiveness and without adverse effect to the environment, whilst economically improving delivery and manufacturing processes. These engineers eventually acquire competencies like: • Drug products • Continuous processing in clean/sterile environment

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Typical work activities: Pharmaceutical engineers work as process engineers in the pharmaceutical industry just as in any other process industry, but their specialization allows them to work in fields particular to the pharmaceutical industry such as containment, validation, aseptic processing and particle technology. This now brings the problem-solving principles and quantitative training of engineering to complement the other scientific fields already involved in drug development. These specialties overlap with other engineering areas as well as non-engineering scientific and medical fields, although in all specialties pharmaceutical engineers tend to have a distinct focus on product and process design and quantitative analysis. Typical design tasks can include: • Design of chemical reactors where bulk drugs can be synthesized on a commercial scale; • Design, development and characterization of drugs for both laboratory and commercial scale; • Process design and development of new pharmaceutical dosage forms; • Design and scale-up of dry granulation processes; • Process modeling of solid oral drug products; • Spray atomization modeling for tablet film coating processes.

4.3.16

Site Engineer [2, 3, 4]

Job description Chemical engineering graduates can also become site engineers in a plant construction site. Site engineers perform a technical, organizational and supervisory role on construction projects. They apply designs and plans to mark out the site and can be involved in projects ranging from small to large projects. This may include central gas processing facilities, refinery construction, offshore platform construction, subsea equipment

Career Diversities in Chemical Engineering 145 fabrication sites, nuclear power plant construction sites, chemical plant construction sites, and so on. A site engineer works as part of the site management team liaising with and working alongside specialist engineers, construction managers, supervisors, planners, surveyors and subcontractors. They share responsibility for site security, health and safety, and the organization and supervision of material and human resources. Typical work activities • Sets out, leveling and surveying the site; • Ensures all materials used and work performed are in line with specifications; • Checks plans, drawings and quantities for accuracy of calculations; • Oversees the selection and requisition of materials and equipment; • Agrees on a price for materials, and makes cost-effective solutions and proposals for the intended project; • Manages, monitors and interprets the contract design documents supplied by the client; • Liaises with any vendors, sub-contractors, supervisors, planners, quantity surveyors and the general workforce involved in the project; • Liaises with the local authority to ensure compliance with local construction regulations and by-laws; • Liaises with clients and their representatives including attending regular meetings to keep them informed of project progress; • Day-to-day management of the site, including supervising and monitoring the site labor force and the work of any subcontractors; • Plans the work and efficiently organizes the plant and site facilities in order to meet agreed deadlines; • Oversees quality control, health and safety matters on site; • Prepares project reports as required; • Resolves any unexpected technical difficulties, and other problems that may arise in a site; • The site engineer acts as the main technical adviser on a construction site for subcontractors, technicians and operatives.

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4.3.17

Production Engineer [2, 3, 4, 5]

Chemical and manufacturing plants require professionals to oversee their equipment and processes. Chemical engineers can be used to maintain production levels of a manufacturing plant or to advise in the purchase and layout of plant equipment. A production engineer basically has a wide knowledge of engineering practices and is aware of the management challenges related to production. The goal is to fulfill the production process in the most efficient, safe and economical way. The chemical engineer here is involved in producing a product in the required quality and quantity in a timely manner. This job title requires interpersonal skills since one is interfacing with chemical operators on a daily basis. These abilities are essential for the performance of coordinating and integrating professionals of multidisciplinary teams. The production engineer is also responsible for the safety of employees. A good deal of time is devoted to working with other departments, such as purchasing (raw materials), procurement, utilities (power), maintenance (repairs), marketing (production schedule), and research and process engineering (new and improved processes). Typical work activities • Selecting and integrating resources. Material, human and financial resources will be considered at high efficiency and low cost while at the same time considering the possibility of continuous further improvement; • Evaluating, monitoring and managing factory production; • Designing, implementing and refining products, services, processes and systems, with respect to constraints and uniqueness of the related communities; • Applying mathematics and statistics to model production systems during decision-making process, hence they are analytical; • Deploying organizational standards for control proceedings and auditing; • Forecasting and analyzing demand in order to improve product/service delivery; • Applying scare resources, production management and sustainability to balance the relation between production systems and the environment; • Managing and optimizing production and information flow, production time and cost.

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4.3.18

Pipeline Engineer [1, 2, 5]

Job description Chemical engineering graduates can also pursue a career in Pipeline engineering. Chemical engineering skills can be applied in this multifaceted, complex and challenging discipline. Pipelines move oil and gas products such as crude oil, natural gas and refined petroleum products such as gasoline, kerosene, diesel, and so on, beneath the ground. Everyday products such as fuel for our cars or cooking gas are transported through these pipelines. Gas pumping stations, gas compressor stations, pipelines, storage terminals, manifolds, control systems, risers, subsea assemblies, jumpers, pipelines, and associated facilities are some of the facilities that pipeline engineers design, construct, operate and troubleshoot— including new installations as well as upgrades and retrofits to existing terminals and platforms. An interdisciplinary approach is applied in pipeline design. They are familiar with risk-based inspection/ inspection management systems, also with international codes and regulations. The engineer’s assignments will vary depending on the nature of projects received from clients and the candidate’s applicable work experience, expertise and proficiency. Typical work activities: • Pipeline engineers provide pipeline sizing, design and calculation and conduct pipeline inspection, integrity and corrosion control for pipelines, risers and associated equipment. In addition, other tasks include troubleshooting, consulting and project management; • Developing P&IDs or mechanical flow sheets for pipelines, pig traps and slug catchers; • Developing and reviewing technical specifications for onshore and offshore pipelines, flexible pipelines, steel catenary risers, and so on, and monitor, when required, their fabrication, acceptance, installation and startup; • Front-End Engineering and Design (FEED) and Detailed Engineering for pipeline additions on new and existing platforms; • Performing troubleshooting and de-bottlenecking of pipeline systems to optimize production; • Preparation and review of riser designs, crossing designs, routing plans and permit documents;

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Introduction to Chemical Engineering • Reviewing riser guard and riser support designs; • Preparation and review of cost estimates for pipeline installation and provision of procurement support; • Developing or altering standard project specifications to meet specific project requirements; • Coordinating with other disciplines to ensure an integrated design that meets the project requirements; • Preparation of data sheets for pipeline instruments and specialty items; • Preparation of pipeline pigging, purging, commissioning, and start-up procedures; • Coordinating and directing auto CAD drafters in the creation of design drawings; • Verification of technical drawings for correctness of design and engineering data; • Developing engineering reports and associated spreadsheets; • Interfacing with project managers, other engineers and clients, including attending project safety, schedule and progress meetings; • Reviewing vendor or fabricator quotations, shop drawings, and related submittals; • Maintenance of project files; • Performing the necessary onshore and offshore field work to obtain accurate information for the design; • Developing regulatory submittals.

There are many exciting pipeline engineering jobs including: • • • • • • • • •

Pipeline/Facilities Design Engineer Pipeline Inspection Engineer Corrosion/Integrity Engineer Pipeline Controls Engineer Pipeline Operations Engineer Subsea Pipeline Engineer Pipeline Mechanical Engineer Subsea Inspection Engineer Consulting Project Engineer

Engineers here can identify research needs and perform study and design follow-up. As part of their roles, they also conduct audits and take part in project technical reviews.

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4.3.19

Petroleum (Production, Reservoir and Drilling) Engineer [2, 3, 4, 5]

Job description Petroleum engineers plan, design and implement the technical side of drilling a hydrocarbon well. They provide specialty expertise in oil and gas drilling, reservoir management and production. They apply sophisticated computer modeling, production technologies, statistics and probability analysis to accomplish this challenging work. Although petroleum engineering is considered outside the periphery of the core chemical engineering discipline, graduates of the latter can, through on-the-job training, move into the main stream of the field. The goal of a petroleum engineer is to maximize hydrocarbon recovery or production at a minimum cost while maintaining a strong emphasis on reducing all associated environmental problems. A petroleum engineer is involved in nearly all levels of oil and gas field evaluation, development and production. There are three major areas of petroleum engineering: • Production Engineers: they analyze, interpret, and optimize the performance of individual oil wells. They study and evaluate artificial lift methods and develop surface equipment systems to separate crude oil, gas, and water. Production engineers manage the interface between the reservoir and the well; this they do through such tasks as (but not limited to) artificial lift, perforations, sand control, downhole flow control and downhole monitoring equipment. They also select surface equipment that separates the produced fluids (crude oil, natural gas and water). Hence, they are in charge of designing the connections between the reservoir and the oil well. • Drilling and Completion Engineers: they plan, design and implement drilling and completion programs for all types of hydrocarbon wells; ensuring safety and economics are taken into account. Drilling engineers manage the technical aspects of crude oil drilling both production and injection wells. • Reservoir Engineers: They study the behavior and characteristics of a petroleum reservoir to determine the drilling and extraction strategy that will be suitable or used to optimize oil or gas recovery; they conduct computer simulation studies to determine optimal development plans

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Typical work activities • Evaluation of potential for basins, planning and coordination of drilling in order to find ways to optimize production – all while ensuring economic viability. • Selecting optimal tubing size and the variety of suitable equipment within the well for different functions; • Liaising with geoscientists and commercial managers in interpreting well-logging results and predicting production potential; • Preparing and compiling detailed development plans of reservoir performance using mathematical models to ensure maximum economic recovery; • Designing the completion – the part of the well that communicates with the reservoir rock and fluids; • Designing the systems that help the well to flow, for example using submersible pumps; • Managing evaluating problems of fluid behavior and production chemistry; • Evaluating and recommending flow rate enhancement by using hydraulic fracturing and acid treatment; for example, the former is used to force fluid into a well and fracture the rock while the latter is used to erode the rock and improve flow path; • Coordinating the maintenance of equipment; • Liaising with separate departments to ensure correct progress with projects and reporting same to clients; • Managing and controlling wells with branches at the bottom (horizontal and multilateral wells); • Applying well and reservoir remote sensing technology and surveillance data to manage the value of the reservoir and choose appropriate engineering interventions; • Managing employee and contractor relationships in relation to health, safety and environmental performance.

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4.3.20

Environment Engineer [1, 3, 4, 5]

Job description Chemical engineers in this area are saddled with the responsibility to develop techniques to recover usable materials, and reduce waste created during manufacture of a product. Some of the equipment they design includes air pollution control and wastewater treatment systems, waste storage and treatment facilities, and soil and groundwater clean-up systems. Environment engineers can also be responsible for monitoring all systems in a facility for compliance with environmental regulations. The environment is one of the key engineering design considerations during process plant design. Hence, developing and expanding the scope of environmental protection has created additional opportunities in small specialist environmental consultancies. This attracts more opportunities for young chemical engineers aspiring to specialize in this area. However, this field of specialty should not be mistaken with the position of environment officer which is an aspect of HSE. Anybody with any degree can be an environment officer but only a graduate engineer can become an environmental engineer. Typical work activities • The chemical engineer in this specialty will be involved in visiting and assessing various sites (including proposed sites for any chemical industry); • Assessing and managing the impacts of human and other activity on the natural and built environment; • Working for local authorities as environment advisor on pollution or effluent control; • Tendering for projects, ranging from environmental audits to major contaminated land reclamation such as water and sewage treatment plants, storm water and river control works; • Performing and organizing company internal and external auditing in environmental matters; • Communicating relevant issues to other technical staff, regulatory authorities, public interest groups and the public; • Developing environmental impact models to assess a range of environmental processes;

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Introduction to Chemical Engineering • Coordinating the preparation of environmental baseline, environmental green book, environmental impact assessments, etc.; • Executing environmental surveys, with the approval of the regulatory authority; • Leading application, in compliance with regulations, reference documents and best practices, of HSE policy in the activities of a chemical/oil and gas company.

4.3.21

Materials Engineer [1, 2, 3, 5]

Job description Chemical engineers in this specialty are responsible for the research, specification, design and development of materials to advance technologies of many kinds. Materials engineers combine or modify materials in different ways to improve the suitability, performance, durability and cost effectiveness of final products. Their expertise lies in understanding the physiochemical properties and behaviors of different substances, from raw materials to finished products. Various types of materials include polymers, ceramics, composites, glass, industrial minerals, metals, plastics, rubber, chemicals and textiles. Materials engineers commonly would specialize in any of the above. Some universities offer chemical and material engineering or chemical engineering and material science as a combined discipline. Materials engineers are expected to play a significant role in finding more energy-efficient, health and environmentally friendly products and processes. Typical work activities Work activities include but are not limited to the following: • Materials engineers use their expertise to design, specify and process materials; • Working as process control engineers, ensuring that the manufacturing process runs smoothly; • Selecting the best combination of materials for definite purposes; • Testing materials to assess how resistant they are to weather, heat, corrosion or chemical attack; • Analyzing material data using computer modeling software; • Assessing and evaluating materials for specific qualities (such as electrical conductivity, durability, renewability);

Career Diversities in Chemical Engineering 153 • Developing novel materials for specific purposes; • Evaluating the implications for waste and other environmental pollution issues of any product or process; • Advising on the flexibility of a plant to new processes and materials; • Troubleshooting and working to solve problems that may arise either during the manufacturing process or with the finished product (e.g., problems caused by daily wear and tear or change of environment); • Working as material quality control engineers during production process; • Monitoring plant conditions and material reactions during material application; • Helping to ensure that finished products comply with national and international legal and quality standards; • Interfacing with manufacturing, technical, research and development, purchasing, marketing, and so on; • Advising on materials inspection, maintenance and repair procedures; • Evaluating cost implications of materials used, in terms of both time and money and creating alternatives.

4.3.22

Piping and Lay-out Engineer [2, 5]

Job description Piping is a system or arrangement of pipes or a network of pipes used to convey fluids—liquids and gases—from one location to another. Within a process plant, the locations are typically one or more equipment items such as pumps, pressure vessels, compressors, turbines, heat exchangers, process heaters, etc. The fluid includes raw, intermediate, and finished chemicals, petroleum products, gas, steam, air, and water; fluidized solids, refrigerants, cryogenic fluids, etc. Piping engineering is another area a chemical engineering graduate can specialize in. The discipline studies the efficient transport of fluid, which is part of the chemical engineering curricula. The array of piping systems (aboveground and underground) range from industrial systems, such as piping for natural gas plants, chemical plants, petroleum refineries and so on. A piping system consists of pipe sections, the in-line components, known as fittings, valves, flanges, gaskets and bolting; pipe supports and strains. Instrumentation and control devices, which are mounted on the flanges, are used to sense and control the pressure, flow rate and temperature of the transmitted fluid. Piping engineering activities

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are noticeable during the detail engineering phase of a project; activities include the engineering, design, detail and layout of process and utility equipment, equipment plot plans, piping arrangements, fabrication drawings and piping and instrumentation. The most important factors a piping engineer considers in the course of carrying out a piping design are process requirements, safety, operability, maintenance, compliance with statutory requirements and economy. Generally, industrial piping engineering can be further broken down into three main subfields which include piping material, piping design and stress analysis. The piping engineering discipline plays a major role in the construction of gas processing, petroleum refinery, chemical, power, pulp and paper and utility industries, etc. Typical work activities Typical work activities or role of piping engineers include: • Preparing plot plan, equipment layouts, piping studies and piping specification; • Reviewing process package; • Checking process piping and power piping to verify that the routing, nozzle loads, hangers, and supports are properly placed and selected such that allowable pipe stress is not exceeded under different situations as sustain, hydro test as per ASME standard; • Applying computer software such as CAESAR II, CAEPIPE and AUTOPIPE, in performing pipe stress analysis; • Estimating quantities (material take-off, MTO or Bill of material, BOM) of piping materials required for a given project; • Reviewing the process data required for converting P&IDs to piping layouts; • Preparation of piping isometric drawings, piping support drawings, piping layout drawings, nozzle orientation for fabricated equipment, firefighting specifications, equipment and piping painting specification, etc.; • Updating the piping and instrumentation diagrams (P&IDs) with piping design information; • Selecting piping material type for a given project – piping material types include carbon steel, low temperature service carbon steel, stainless steel, non-ferrous metals (including inconel, incoloy, cupro-nickel, and so on), non-metallic (PVC, HDPE, tempered glass, and others).

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4.3.23

Project Engineer [2, 3,5]

Job description Chemical engineers working as project engineers oversee the design and construction of specific processes on a given facility. After construction, they may assist in equipment commissioning and testing, operator training, and plant start-up. Project managers oversee the overall design and construction of specific processes, then manage a group of project engineers during detailed design and construction of a new facility. A project engineer performs work that interfaces with engineering and project management up to the technical workers who contribute to the construction of chemical plants or any other product delivery. In some cases, where the project is a small one or for a package within a large project, the project engineer is the same as a project manager. However, in most cases these project engineers work under a project manager and can have a responsibility of being the deputy project manager. This is usually the path to a project manager or technical manager position.

Figure 4.3.12 Project Engineer at Work (Image Source: http://www.shell.com/careers/ experienced-professionals/technical-careers/project-engineering.html, 2016).

Though project engineers do not carry out hands-on engineering design work, they must have engineering design experience to be able to interpret designs and direct technical solutions. He or she must also have knowledge of project management to be able to ensure the job is constructed per the project plans, and assist project controls, including budgeting, scheduling, and planning. Typical work activities Typical roles of the project engineer include: • Liaising with third-party contractors to ensure all delivered equipment is fit for purpose;

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Introduction to Chemical Engineering • Planning and managing resources and budget for efficient delivery of all projects. • Managing and accounting for one or several packages within a chemical plant construction project; • Identifying technical problems and ensuring solutions are implemented; • Leading the performance management of vendors; • Coordinating project execution, ensuring it is being built correctly; • Reviewing engineering deliverables and project status reports; redlining drawings; budget monitoring and trend tracking; bill of materials creation and maintenance; effective communications between engineering, construction, and project controls groups; • Interpreting clients’ requirements to site construction team; • Project engineer can be involved from initiation to closeout, where he or she works to deliver engineering modifications and projects safely to the business or for clients; • Leading inter-discipline coordination and overall quality control of a project; • Responsible for providing technical specification interpretation, technical guidance and engineering support for various chemical, oil or gas plant development projects; • Ensuring engineering and project management team are having strong relationships with a diverse range of people, motivating individuals, setting goals and ensuring the team meets them; • Managing interfaces between all project parties and disciplines and implementing an efficient handover from construction to operations.

4.3.24

Cost Control/Cost Engineer [2, 5]

Overview A chemical engineering graduate by virtue of his or her training can specialize as a cost engineer. According to Wikipedia, cost engineering is that area of engineering practice where engineering judgement and experience are utilized in the application of scientific principles and techniques to problems of cost estimation; cost control; business planning and management science; profitability analysis; and project management, planning & scheduling.

Career Diversities in Chemical Engineering 157 (See  “Cost Engineering”, Wikipedia.org, 14 August 2016). Cost engineers apply cost engineering and cost management principles, project management methodology and specialized technology to their technical projects. Some titles or positions in cost engineering practice include cost engineer, cost estimator and cost control engineer/cost analyst and so on. These positions are often interchangeable. They are closely related but slightly different. They are tripartite costing job positions. However, some core engineering firm will insist on a degree in engineering for a cost engineer position. A cost estimator prepares capital and operating cost estimates. He or she monitors project costs, completes risk analyses thereby identifying improvements. He also maintains an estimating/experience database, guidelines, procedures and best practices. A cost analyst/controller establishes project control systems. He or she oversees project performance in terms of scope, time and cost. He also identifies and monitors project risks, and hence recommends improvement measures. Cost control involves ensuring that a project stays within its estimated and agreed costs. Cost controllers are also involved in planning. Planning involves thinking through time-related aspects of alternative designs or courses of action and costs, whilst looking at the benefits that may arise. For example, calculating and comparing costs and benefits choosing alternatives. Chemical engineers are well trained to work as cost control/cost engineers in engineering companies or any oil and gas company. Cost engineers work to ensure value for money using engineering knowledge to assess and control costs. Chemical engineering students who wish to specialize in this area should pay more attention to chemical plant design and economics as well as engineering management courses. Typical work activities: • Establishes and manages effectively a cost control system to support the project manager’s decision-making process so that project can be completed within the budget (without cost overrun); • Ensures any deviation from project plan is promptly spotted and analyzed; final impact is estimated, and the effect of corrective actions proffered is monitored; • Prepares project estimates to complete (EAC), forecast and definition of corrective actions where the trend seems unhealthy;

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4.3.25

Contracts Engineer [4, 5]

Overview Contract engineering is also another area a graduate chemical engineer can specialize in. Specialized or technical projects may require an administrator with a university degree in engineering. He or she would need to get a construction contract administrator certification. A contracts engineer is responsible for conducting reviews and checking legal aspects of a contract award, managing and preparing a final contract to be awarded. He or she is also responsible for preparing and drafting commercial bids and tenders, estimating the costs of a project and ensuring that the costs are controlled. The role of the contracts engineer is critical in a chemical plant. Graduates should note that this position requires technical knowledge and diversified capabilities in contract management, cost effectiveness, legal or economical aspects, and negotiation skills. It also requires high coordination and communication with end users, HSE, local and international contractors. Typical work activities: Contracts engineers’ typical work activities include: • Providing hands-on support to management on the review and updating of tender and contracts standards, checklists and general procedures; • Evaluating contract change orders and claims;  • Participating in cost analysis review meetings with the senior management; • Monitoring status of documentations such as outgoing and incoming letters, transmittals, various contract requirements and deliverables;

Career Diversities in Chemical Engineering 159 • Providing strategic support in respect of internal and external negotiation meetings pertaining to high value tenders and contracts; • Monitoring and ensuring that project procedures are strictly followed to avoid deviation that will cause contention later; • Keeping management appraised of all developments that may impact the successful delivery of contracts he is employed to manage; • Being directly responsible for the contract administration aspects of the call for tender of contracts; • Preparing call for tender documentation and specific tender and tender evaluation procedures in line with project and company procedures; • Providing general support and advice on contractual and procurement matters as required to support company’s operations; • Contract engineer also provides legal contractual advisory to all departments throughout contract implementation phase to protect organizational objectives within legal boundaries; and in the event of a dispute with the contractor or client, negotiate and resolve the dispute to the mutual satisfaction of both parties.

4.3.26

Chemical Manufacturing Engineer [1, 2, 3, 4, 5]

Overview A chemical manufacturing engineer will research, plan, design, set up, modify, optimize and monitor a manufacturing process. Chemical engineering graduates wishing to specialize here should note that this is just a change in job title. This job option can be the same as a “chemical engineer, control engineer or process engineer” position in some industrial environment. The engineer here works to produce high-quality goods efficiently in the most cost-effective methods and is conscious of the environment and its protection. Chemical manufacturing engineers are designers, as well as analytical and creative thinkers. They can work independently but also contribute as a member of a multidisciplinary engineering group. Chemical manufacturing engineers have the benefit of working in a wide range of areas, as the basic manufacturing principles apply to all chemical and process industries. They are employed in numerous sectors, including paper and pulp, ceramics, plastics, pharmaceuticals petroleum refining, food and drink, chemicals, oil and metals.

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Typical work activities A chemical manufacturing engineer is employed in various industries and in numerous roles, which may include: • Designing and operation of integrated systems for the production of high-quality, economically competitive chemical products; • Researching, designing and developing of systems and processes; • Designing new systems and processes for the introduction of novel products or for the improvement of existing products; • Focusing on cost-saving technologies, quality, reliability, safety, and High-Performance Work Systems; • Working on different aspects of project development and consistently looking for ways to improve the manufacturing processes; • Working with other disciplines such as project control, design engineers, finance, human resources personnel and so on, to manage budget aspects and recruitment of junior graduate engineers; • Organizing plant start-up and shutdown schedules to ensure efficiency and profitability;  • Liaising with the research and development department (R&D) to ensure company is at forefront of groundbreaking research; • Tendering and issuing order for new equipment to ensure the highest quality at the best price; • Applying leading-edge analysis, modeling and simulation tools to improve the capability of processes and to develop simulated process equipment to use for option analysis and optimization.

4.3.27

Quality Process Engineer/Quality Control Engineer [2, 3, 4]

Overview Quality inspection is another area a graduate chemical engineer can choose to build a career in. In an industrial setting, quality control and inspection professionals consult and provide services to ensure compliance with approved engineering design specifications, standards and procedures, and

Career Diversities in Chemical Engineering 161 with environmental, health and safety regulations. Within quality control and inspection there are many areas of specialty. Quality engineers work in manufacturing plants where they take responsibility for the quality of a company’s products. Engineers here plan and direct activities concerned with development, application, and maintenance of quality standards for industrial processes, materials and products. They develop and initiate standards and methods for inspecting, evaluating, and testing products and materials. Chemical engineers in this area monitor the manufacture of chemical products to ensure that quality standards are maintained. Quality assurance (QA) aims to ensure that the product or service an organization provides is fit for purpose and meets both external and internal requirements, including legal compliance and client’s expectations. Typical work activities include: • Preparing procedures for evaluating, and reporting quality and reliability data; • Analyzing data and monitoring implementation of all process and quality control strategy; • Developing and maintaining project quality plans; • Providing construction projects with subject matter expertise regarding quality assurance and quality control systems; • Confirming implementation and verification of quality processes; • Defining quality assurance (QA) and quality control expectations, and performing project-wide assessments; • Develop and execute various improvements to quality process and develop new processes on same; • Issuing non-conformance reports to when defects are identified or when there is deviation from approved construction procedure; • Monitoring and advising on the performance of the quality management system; producing data, charts and reports on performance, measuring against set indicators thereby producing statistical reports; • Designing, implementing and maintaining the company’s quality program for large, multidisciplinary projects with quality controls; • Working with purchasing staff to establish quality requirements from external suppliers;

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A project quality engineer can rise in an organization up to a quality manager. A quality manager, sometimes called a quality assurance manager, is responsible for coordinating the activities required to meet quality standards. He or she liaises with other managers and staff throughout the organization to ensure that the QA system is functioning properly. Where applicable, the quality manager advises on changes and their implementation and provides training, tools and techniques to enable others to achieve quality.

4.3.28

Others

Other related job options and/or job titles available that a graduate chemical engineer can aspire to include: • • • • • • • • • • • • • • • • •

Chemical Engineering Lecturer Chemical Process Risk Engineer Ceramics Engineer Process Simulation Engineer Plastics/Polymer Engineer Petrochemical Engineer Plant Engineer Adhesives Engineer Biotechnical Engineer Waste Treatment Engineer Pulp and Paper Engineer Project Services Engineer Interface Engineer Application Engineer Auto-CAD Engineer Waste Management Engineer Project Control Engineer, and so on.

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4.4 Chemical Engineering Professional Critical Success Factors Chemical engineering professional critical success factors include critical knowledge, critical thinking, critical experience and critical leadership. Critical Knowledge The critical knowledge factor means that the individual should have previous knowledge of chemical engineering standpoints and principles. Also expected is the knowledge of design methodology, design tools (software, procedures, and so on) and principles involved in designing a process and specifying required process hardware and layout. Other critical knowledge required includes concept evaluation and concept analysis; troubleshooting, systems evaluation and systems analysis; knowledge of chemistry, including chemical structure, reactions, properties and compositions of chemical compounds; knowledge of life sciences including organisms, cells, functions and how they depend on and interact with each other. Critical Thinking The critical thinking factor is such that the individual can independently analyze, synthesize, evaluate and interpret information, all of which involve applying the principles of logic and reasoning to ascertain the strengths and flaws of alternative solutions, conditions or steps to solving complex problems.

Critical Knowledge

Critical Thinking

Critical Experience

Critical Leadership

Figure 4.3.13 Critical Success Factors.

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Chemical process engineering involves evaluation, analysis and interpretation of data, assumptions, and concept selection from alternatives. Hence, critical thinking skill is a critical success factor in the chemical engineering discipline. A typical critical thinker is usually inquisitive, determined, diligent in seeking solutions, broad minded, well-informed, flexible, adaptable, dispassionate in evaluation, sincere in facing technical critiquing, hardworking, focused, showing good sense of judgment, willing to review and correct, clear about issues, assiduous in seeking relevant information, rational in the selection of criteria, and persistent in seeking optimal solutions to problems. Critical Experience Work experience is critical to success in chemical engineering. This is because academics more often than not provide theoretical experience, while work provides real-world experience of various applications of the chemical engineering concept. Critics, consequently, do argue here that chemical engineers who never worked in the industry before becoming lecturers are not engineers. However, most critical thinking chemical engineering lecturers are aware of this gap and have devised ways of constantly interacting with the industrial sector to close the gap. Chemical engineering graduates begin their work experience as trainees, and depending on the individual’s rate of development, will rise to become engineers. Critical leadership Critical leadership capability is also a critical requirement for success in chemical engineering. An engineer is said to be succeeding if he or she is growing in the field. And by growing is meant that the individual will get to a leadership position as an engineering lead. Leadership, however, is not an exclusive reserve of technical leads; even a trainee can find himself in a leadership position while working in a team. Hence, to be a successful chemical engineer, it is critical that the individual possesses great leadership skills. This is necessary so that the individual can set ambitious strategic goals; be able to influence others; manage performance to high standards, work in synergy with other disciplines which is mostly required in the field; share ideas, motivate and direct people to get things done; identify the best people for a given design job; mentor or coach younger engineers; and so on. Again, the chemical engineer should be able to bring people together and reconcile any disagreement arising during engineering design. Conflict management thus is not an option but an essential part of the duties of a chemical engineer.

5 Design and Chemical Engineering Practice 5.1 Introduction Design activity is common to all engineering disciplines, and it is what separates engineering from science. According to Clive and others (2005) [65], “engineering design is a systematic, intelligent process in which designers generate, evaluate, and specify concepts for devices, systems, or processes whose form and function achieve clients’ objectives or users’ needs while satisfying a specified set of constraints”. This description views engineering design as a thoughtful process that depends on the systematic, intelligent generation of design concepts and the specifications that make it likely to realize these concepts. In chemical engineering, design usually refers to design of a process, process equipment or a chemical processing plant while considering safety, environmental and economic aspects. Chemical engineering design proceeds iteratively; it starts from sketchy, coarse-level designs and then gets to detailed designs which are ultimately needed for building the respective chemical plant. In addition, engineers rely on scientific principles, intuition, experience and heuristics when designing a process. Businessdictionary.com defines heuristics as a trial-and-error procedure for reaching an unclear goal through incremental exploration, and by employing known criteria to unknown factors. Chemical laboratory is usually the starting point for novel chemical development. But for existing chemical technology such as in oil and gas, designers usually do not start from scratch, especially for complex projects. Chemical engineers use data from laboratory experiments, pilot plant, full-scale operating facilities or data from computer simulation in designing chemical plant or process. Other sources of information include proprietary design criteria provided by process licensors, published scientific data, and so on. Chemical engineering design is governed by three primary physical laws: conservation of mass, conservation of momentum and conservation of energy. Principles of thermodynamics, reaction kinetics and transport phenomena are applied by chemical engineers in evaluating the mass and Uche Nnaji (ed.) Introduction to Chemical Engineering: For Chemical Engineers and Students, (165–252) © 2019 Scrivener Publishing LLC

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energy conservation. Nowadays, complex computer simulation software models are used to solve mass and energy balances. These simulators do have built-in modules to simulate a variety of common unit operations. Computer simulations can identify weaknesses in designs and allow engineers to choose better alternatives. Some of the available software for process design include ASPEN HYSYS, DISTIL, PRO II, HEXTRAN, ICARUS, PROSIN (PROcess SYNthesis) and others. Chemical engineers design chemical production equipment and entire chemical plants: Piping and pump sizing and specification Chemical reactors * Continuous stirred-tank reactor * Plug flow reactor * Catalytic reactor * Separation equipment Distillation column * Extraction column * Evaporation * Filtering * Reverse osmosis Process control and instrumentation

Cost analysis is applied as an initial screening to eliminate unprofitable designs. If a process appears lucrative, then other factors are considered. The general goal in plant design is to construct or synthesize “optimum designs” in the neighborhood of the desired constraints. In order words, the goal is to design a plant capable of producing a specific or a range of chemicals at the desired tonnage and at the right price. Constraints or factors to be considered may include capital cost, available space, safety concerns at unit and plant level, budget, pay-back, market share and regulations. Others include environmental impact and projected effluents and emissions, both immediate and future; waste production, operating and maintenance costs, contractual penalties, standard and codes of practice, physical and chemical limitations, market share, and so on.

5.2 Chemical Process and Plant Development Steps 5.2.1 General Chemical process design forms the nucleus of chemical engineering discipline. It is highly creative and entails exploring many design alternatives.

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Both unexpected and planned feedback can very often occur. Chemical processes are complex and these processes most times include substances of high chemical reactivity, high corrosivity, and high toxicity, operating at high pressures and temperatures. These characteristics can lead to multiple potentially serious consequences, including explosions, environmental damage, and threats to human health. Consequently, conceptual or new chemical process development usually applies all necessary natural and life sciences. Hence, engineering design is said to be an exercise in creativity and innovation.

Figure 5.2.1 Process unit (sludge catcher) of a gas plant.

According to Mizrahi (2002) [66], a new process is born through: • • • • •

Personal motivation Normal research and development activity Corporate function Financial and commercial rewards False tests

Process plant design is typically performed in an evolutionary way. The following chart illustrates the chronological steps in process development leading to plant design and construction.

Introduction to Chemical Engineering

Laboratory Experiments

• Choice of Chemical Route • Modification, Improvement and Optimization of Synthesis • Generation of Process Development Data

Process Design

• Process Concept • First Flow-sheet • Process Optimization (Computer Simulations) • Advanced Flow-sheet

Process Evaluation

• Reactors, Separation or Purification Units and so on. • Mini-plant or Individual Steps in Pilot Plant • Integrated Pilot Plant • Demonstration Plant • Abandon Development

Prodcut Evaluation & Marketing

• Return on Investment (ROI) Calculation • The Net Present Value (NPV) Method • Sensitivity Analysis

Engineering Design

• Conceptual/Basic Engineering Design/Feasibility Study • Front-End Engineering Design (FEED) • Detailed Process & Engineering Design

Construction

Commissioning

Chemical Industries

Development of Individual Process Units

• Procurement • Fabrication • Installation • Pre-commissioning and commissioning • Start-up

Oil & Gas Industries

Engineering Design & Construction

Process Design

Process Development

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Figure 5.2.2 Life cycle of a chemical/oil and gas plant (Scale-up Activity Model).

5.2.2 Process and Technology Development Basically, process development is the translation of the bench or laboratory scale chemistry into a means whereby the material can be produced on a large scale. This is where chemical engineering expertise comes into play. This effort is costly and usually a multifarious endeavor. Most times chemists research chemical reactions or other chemical principles in a laboratory experiment. The information obtained is then used by chemical engineers, along with expertise of their own, to convert to a chemical process (process development) and scale up the batch size or capacity. Scale-up effort is complex in that what works at bench level does not always work at production level. Mixing compounds in a laboratory apparatus for a few minutes, for example, may not guarantee a consistent result when 15,000 liters of same is being mixed.

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There are some important data for process development, and they include: • Material properties • Physicochemical data • Ecological and toxicological data (Biological-ecological parameters & toxicity) • Costs of raw materials, intermediates, and end products • Energy and equipment costs • Online literature searches While developing a chemical process, at least four reports must be completed: (i)

During the laboratory stage – This report mainly says whether the adopted synthetic route should be followed or not; (ii) At the commencement of process development – this report asks questions such as, has enough research been done? Is there sufficient knowledge to move to the technical development phase? (iii) During process development – the process study; (iv) At the end of process development – the project study. Process development can be said to have come to a certain conclusion with the completion of the project study. A strategic economic decision can therefore be made by the investor on the basis of the available information, which includes marketing studies, patent situation, project study and so on, whereby all the boundary conditions are positive. These data will be used to commence conceptual design or feasibility studies (see conceptual design section). That is if the decision by the Owner Company is positive, then an internal or external engineering unit will be commissioned to prepare a feasibility study. A project study report typically includes the following items: • • • • •

A summary A basic flow diagram A process flow diagram (PFD) and a narrative of the process A waste-disposal flow diagram An estimate of the capital expenditure costs

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The steps for chemical process development as shown in Figure 5.2.2 include: laboratory experiments, process design, developing individual process units, process evaluation, product evaluation and marketing. Laboratory Experiments Process development begins with laboratory experiments. A team of discovery chemists and conceptual design engineers (chemical engineers) usually work together in the laboratory. This is the most critical phase in the process development for value-added chemicals (products). The aim at this stage is to translate the idea or concept into a process definition. In the case of chemicals development, exploratory or preliminary laboratory experiments are carried out to confirm a route which will produce the desired intermediates and products. Many process routes based upon literature studies and preliminary laboratory experiments, which may require different raw materials, are pursued before settling for a particular route. Preliminary experimental data to be generated include qualitative data on conversion, selectivity and yield. Usually, the chemical route is selected based on cost of raw materials. However, other important factors must be considered before making the selection.

Some useful design data being generated from laboratory include: -

Feed Rates Reaction Kinetics Conversions Selectivity on Operating Conditions Heat Sensitivity of Mixtures Heat of Reaction and Other Caloric Properties Concentration Versus Time Profile for Key Components of the Reaction Mixture Temperature Profile Rate of Gas Evolution Measured Over Reaction Period Density and Viscosity of the Reaction Mixture Versus Time Type of Separations Thermal Stability

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Some of the data above are required in simulation program to determine potential toxicity, safety, and impact on the environment. A critical ingredient for success in this phase is a team of discovery chemists and conceptual design chemical engineers working shoulder-toshoulder under the same leader in the same laboratory. Laboratory studies are carried out constantly throughout the period of process development. Outcomes of laboratory phase are chemical route(s), estimated raw materials costs, a preliminary sketch of the manufacturing process scheme(s), and the scope of a research program to determine the key data and models needed for process design in in the next phase. A preliminary flowsheet sketch can show the stages of the manufacturing process (see block process flow diagram in Section 5.2.10). The laboratory experimental phase culminates in the preparation of a preliminary process definition document. This is usually prepared and presented by an experienced process engineer who would apply past experience and process design knowledge in making assumptions and considerations, where applicable. As Mizrahi (2002) [66] observed, the document will include: • Results from a comprehensive literature survey, describing what is generally known in this particular field; • Division of the process into defined sections and interconnecting streams, as shown on a block diagram; • Calculation of the first process material and heat balances; • Definition of at least one feasible implementation scheme; • Projection of an industrial implementation activity plan; • A detailed list of critical feasibility tests. Laboratory

Mini/Pilot Plant

Commercial

Most times, the primary research used to develop a bench-scale or laboratory process is performed by researchers (chemists) who have little or no experience with large-scale operations. Hence, chemical engineers working together with these scientists will understand any additional data that will adequately address issues that can be expected to arise in pilot operations. This is particularly vital because scale-up engineers typically assume that the core process technology data obtained from primary research works in ideal conditions. This is in addition to the fact that information obtained in the laboratory is much cheaper than obtaining the information in a pilot operation.

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Process Synthesis and Design Process design is the design of processes for anticipated physical and/or chemical transformation of materials. Processes usually include many unit operations. Process design is an optimization problem whereby the challenge is how to achieve the design objective in the presence of usually conflicting constraints. Design in chemical engineering, therefore, begins with development of a chemical process. This is the starting point of the technology development. Constructive thinking and creative ideas are applied to lower the investment costs. The engineer at this point begins to develop the first flow-sheet (process flow diagram), otherwise known as process circuit. Further study of multiple development options occurs with the objective of identifying a single process concept for progression to the optimization stage. Optimization of units and subunits processes must begin at this stage. Process optimization is performed by altering the process to optimize some identified set of parameters without violating some constraint. Process optimization is one of the key quantitative tools in scale-up decision making. Optimal solution is systematically determined by using chemical engineering methods and algorithms. Some computer simulation software as stated in the introductory section can also be used for this purpose. Further effort is made by the engineer to get a better estimate of the flowsheet and unit operations for the chosen chemical route. The essence is to ensure that the process is both technically and economically feasible. Similarly, process synthesis is a step in process design where the process (chemical) engineer selects the component parts and how to interconnect them to create his flowsheet. Process system synthesis on the other hand is an action of generating the optimal interconnection of processing units as well as the optimal type and design of the units within a process system. Hence, by so doing, the most economical process flowsheet will be systematically developed. Once the flowsheet structure has been defined, computer simulation of the process can be performed. It should be noted that some parameters may be assumed at this stage. The simulation model is used to predict flow rates, temperature, pressure, compositions, and so on. A process is said to be completely designed when all the mass flow rates, energy, temperatures and pressure requirements in all units of the process are known. The process engineer would then generate specification for all process equipment and ensure that all pieces fit. The objective of process synthesis is to find the cheapest way to efficiently convert raw materials into desired products and considers the constraints, such as product quality, yield, energy consumption, process safety and environment.

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The overall goal of process design is to develop one or two most favored solutions in enough detail that reasonable financial analysis can be performed, safety and environmental issues can be identified and their risk grasped.

Figure 5.2.3 Process Design Route Consideration. (Picture sourced at: http://www. uniteltech.com/services/feasibility-study, 2016)

The process design has the following goals (Mody and Strong, 2006) [67]: • Eliminate solutions with as little effort as possible • Produce a financial estimate • Understand the risk that the process poses to society and environment • Produce the documentation required to build the process Development of Individual Process Units Having optimized the process design to an extent, the next step will be to begin to develop the individual units of the process. Each unit represents process equipment such as a reactor, separators, distillation tower, adsorption column, dryers and cooling towers, and so on. The individual process steps are studied in more detail, including experimental, in the laboratory and/or by using computer modeling software such as the types stated in the introductory part of this chapter. This is to

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Figure 5.2.4 A process unit (Credit: Schlumberger).

minimize the level of uncertainty emanating from insufficient knowledge. Additional information gotten from these studies is fed into the preliminary process flowsheet (block diagram) that has been produced. Process Evaluation The next step is the evaluation of the process, including testing some critical process units in mini or pilot plants. Experiments are conducted to determine the physical properties required for conceptual engineering design. The experiment is performed also to determine the effect of parameters such as reactant molar ratios, temperature and pressure on selectivity and conversions, catalyst composition and so on (S. B. Gadewer and others, 2006) [68]. Other reasons include: Providing data for evaluating process economics, including capital and operating costs; Determining the potential for scale buildup in processing equipment and methods to minimize scaling; Testing materials of construction; obtaining environmental data for permitting; performing catalyst performance tests to determine, or confirm, yield and selectivity data; measuring the lifetime of a process catalyst under a variety of operating conditions; determining the reagent consumptions expected in the commercial plant; providing sample product for customer evaluation; training personnel for a full-scale commercial plant operation, and so on. Chemical process is expected to be operated continuously, hence, an automated micro or mini plant is usually run for weeks non-stop. Mini plants are usually set up in an explosive-proof room using the same laboratory apparatus, such as columns, condensers, pumps and so on. Control and measuring instruments are standard components normally connected to a small process control system (Labview). Evaluating the process in a mini plant leads to cost reduction because a pilot plant can be expensive. Depending on the complexities of the process, the process evaluation with mini or pilot plants can be skipped. They are required if (1) the scale-up risk is too large to proceed from the mini plant to

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the commercial plant, (2) the process requires several critical stages, (3) a novel technology is being used, (4) it is indispensable to provide a demonstrative product quantities. To design a mini plant, a hypothetical large-scale plant should be scaled down. Similarly, a pilot plant should be designed as scaled-down version of the commercial-scale plant and not by scaling up the existing mini plant. Normally, when the industrial plant is started up, the pilot plant is operated concurrently so that any problem which may arise in the former can be dealt with rapidly. The term pilot plant and demonstration plant are often used interchangeably, but commonly a pilot plant is smaller in scale than a demonstration plant. Demonstration scale is basically operating the mini plant equipment at full commercial feed rates over an extended period of time to prove operational stability. The design of a demonstration scale plant for a continuous process usually resembles closely that of the expected future commercial plant, although at a much lower yield. For demonstration plants, equipment and process flowsheet much more closely look like commercial-scale operations. The most important factor in scaling up from pilot plant is to make certain that the equipment used in the pilot plant is scalable to commercial size. It should be noted that process pilot plant development involves complex engineering analysis which includes creating a process flow diagram (PFD), developing basic piping and instrumentation diagrams (P&IDs) and initial equipment layouts; engineering modeling and optimization, design of automation strategies for the system, where applicable; procurement, fabrication and assembly, testing of completed systems, including system controls; installation and commissioning/startup. The results of the tests performed in pilot and demonstration plants are key to optimizing the commercial plant flowsheet.

Figure 5.2.5 A Mini Plant (Picture sourced at: http://appliedchemical.com/services/processplant-design/, 2016).

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All relevant safety considerations expected in commercial operation must form part of the pilot design. Also, it must be noted that where novel technologies are being scaled up in a pilot plant, potential safety hazards may not be as well known as for mature technologies. Pilot plant scale up is expected to give accurate prediction of the performance of the commercial plant, if properly planned and executed. Hence, pilot plant results can be translated into design criteria for scaling up to the commercial operation. Product Evaluation and Marketing Cost is the most important factor to be considered before deciding whether to pursue a process or abandon it. Most strategic product- and process-development decisions are made at the initial stage of the life of a project—detailed rate on reaction kinetics, phase behavior, chemical properties, and so on, are incomplete or vague, and investment decisions must be made based on mostly qualitative information obtained during the process discovery phase. Some of the more commonly used techniques of economic evaluation and the criteria used to judge economic performance are discounted cash flow (time value of money), rate of return calculations. Investment cost is evaluated based on the equipment sizes and in addition to production cost, net present value (NPV) is used as an indicator. Silla (2003) [69] lists hierarchical activity steps in economic evaluation of a process as follows: 1. 2. 3. 4. 5. 6. 7.

Prepare a process flow diagram Calculate mass and energy flows Size major equipment Estimate the capital cost Estimate the production cost Forecast the product sales price Estimate the return on investment

As process development comes to a certain conclusion, available information is put together as a document known as basic engineering design data (BEDD) which will serve as the basis for commencing conceptual engineering studies. (For more on the BEDD, see Conceptual/Feasibility Study stage.)

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5.2.3 Engineering Design 5.2.3.1 General Engineering design phase is usually divided into three parts namely, conceptual/basic engineering design/feasibility studies, front end engineering design (FEED) and detailed engineering design. The scope of the conceptual design phase is a function of the type of industry being developed. For a chemical industry, the phase will be more of a feasibility study, since the process has been selected and developed to a large extent in the previous steps. For an oil and gas plant, the process design generally begins from the conceptual phase, which is usually the starting point. Hence, attempt is being made in this book to harmonize the life cycle of both a chemical and oil/gas plant. The chart in Figure 5.2.6 shows the harmonized model. An overview of the main activities and data flows associated with the life cycle of a process plant from conceptual design up to commissioning is shown in the following chart. It shows the main interaction between

Management Activities *Establish Engineering Policy & Standards • Produce & Maintain Feasibility Financial Case • Control Engineering & Construction Activities • Get Agreement with Regulatory Bodies

Select Process Technology

Produce Conceptual/Basic Process Design

Regulatory Bodies

Produce Detailed Process Design

• Define Overall Project Requirement • Determine Candidate Process • Design Basic Process • Provide input to Feasibility/Financial Case • Ascertain Safety/Regulatory Requirements

Commission Process & Handover Plant • Produce Commisioning Plan • Train Commissioning Personnel • Commission Plant • Carry out Acceptance Testing • Handover Plant to Operation

• Produce P&ID • Produce Functional Specification for Process Equipment • Produce Control Requirement Specification • Fulfil Safety Requirements • Produce Plant Operating Procedure

Produce Detailed Engineering Design

Produce Conceptual/Basic Engineering Design • Determining Engineering Approach • Produce Conceptual/Basic Mech. Eng. Design • Produce Conceptual/Basic Mech. Elect. Design • Produce Conceptual/Basic Control & Inst. Eng. Design • Produce Conceptual/Basic Safety Eng. Design • Define Preliminary Plant Layouts • Produce Conceptual/Basic Civil/Structural Eng. Design

• Produce detailed Mech. Eng. Design • Produce detailed Elect. Eng. Design • Produce detailed Control & Inst. Design • Produce Layout & Construction Design • Produce Building & Plant Services Design • Produce Detailed Civil/Structural Eng. Design

Construct & Pre-Commission Plant

• Produce Construction Plans • Establish Construction Services • Fabricate and Construct Plant • Produce As-Built Surveys • Pre-Commission Plant • Handover to Plant Commissioning

FEED

Suppliers & Fabricators

Procure & Control 1. Maintain Suppliers List 2. Issue Enquires 3. Evaluate Bids 6. Inspect 7. Release for Shipment from Suppliers

Figure 5.2.6 Process Engineering Design Model.

4. Commit Purchase 5. Expedite Manufacture 8. Ship Goods from Supplier 9. Control & Issue Equipment & Matls.

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major phases of engineering and construction activities in the process plant life cycle. The following chart indicates the average timeline for a process plant from conceptual design to commissioning:

3

6

Conceptual Design Basic/FEED 12 Detailed Engineering Design & Procurement

24

Construction

18

Precomminsioning & Commissioning

Figure 5.2.7 Average Timeline for Process Plant Development.

5.2.3.2 Conceptual/Basic Engineering Design/Feasibility Study As process development comes to a certain conclusion, either the Owner engineering department or an external engineering firm will be tasked to commence a feasibility study of the proposed project. Various design options will be evaluated and a process scheme that will serve as the basis for the project moving forward will be selected. The aim of a conceptual or feasibility study is to evaluate the potential investment, develop a business case and define specific requirements from which a project budget and execution plan can be developed. Feasibility study activities are geared toward reviewing and defining any remaining sub-options and then developing the functional specifications for the required facilities or plant. The key factor in this study is usually to get an understanding of the economic and technical feasibility of a number of options as quickly and cheaply as possible. Again, this point in the project is an important decision gate to determine if the project should move forward or be jettisoned. It involves developing sufficient strategic information with which Owner Company can address risk and make decisions to commit resources so as to maximize

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the potential for success. The phase sets the direction for the rest of the project and defines overall project requirements. It can be noted that conceptual design of chemical processes is an attempt to design a chemical process rather than process plant, while conceptual engineering design attempts to design a process plant. Various studies take place at this stage to figure out technical issues and estimate rough investment cost. The study defines the level of design definition required. This can range from a fairly high-level definition for preparation of a feasibility (+-30% accuracy) cost estimate, via a more detailed definition for preparation of a budget (+-15% accuracy) cost estimate, to a complete design definition which would allow a control (+-10% accuracy) cost estimate. The engineer must decide and justify the level of definition required from this stage. In the case of oil and gas processing facilities or plants, at the commencement of a conceptual design a development concept will normally have been agreed, including an identification of the facilities required. Also, this design phase includes the development of detailed process simulations to define the process or process options. At this point the simulations are generally complex and include all major unit operations. Example of such commercial software is AspenONE Engineering suite which includes Aspen Plus and Aspen HYSYS. Detailed heat and material balances corresponding to the process simulations will be generated. Major process equipment is defined at this phase. A major equipment list specifying the key process parameters of each piece of the process equipment is developed. These are subject to change after detailed simulation models are established during basic or front-end engineering.

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Sale gas

Dry gas

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Figure 5.2.8 Process Flow Scheme of Natural Gas Dehydration Plant. [157]

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This list is an important input to the cost estimation work. The chemical engineer employs a number of cost estimation methods and tools to efficiently develop cost estimates with available data and project information. Past experience and equipment factored models are often applied at this stage. In the oil and gas industry most of the processes are known and frozen, hence the conceptual design often starts from a package of data known as basic engineering design data (BEDD). It contains more of site-specific parameters and typically is reused many times with different projects. A BEDD document usually includes plant location, geotechnical data, utilities, key plot plan, climatic conditions, general instructions and information, language, units of measure, HSE requirements, climatic data, environmental regulations/ local codes, and so on. The document is typically based on data supplied by Owner Company, the public and governmental sources. The conceptual study contractor will update the BEDD at the end of this phase. The document, hence, is a live document which will be updated at every phase of the project. This document, however, should not be confused with basis of design. (Process) basis of design (PBD) or design philosophy is the final document arising from conceptual studies. It usually contains a simplified schematic of the process flow, the capacity, utility data, feed stocks with compositions, products with specifications, and battery limit conditions of process streams to and from unit interfaces. It may define the broad limits of the subsequent FEED study. It will be crucial to ensure that the design basis is current or valid and mutually understood by Owner Company, licensor, and contractor in order to have a successful project. Design philosophy will record the standards and philosophies used, together with underlying assumptions and justifications for the development choice. Moran (2015) [68] observed that in the absence of written philosophy, a second engineer at the detailed design stage might attempt to apply the ones he or she would have chosen, and the plant may become subject to pointless expensive and extensive redesign. The process engineer would normally commence the conceptual studies by setting up (most commonly in spreadsheet) a process heat and material balance model linking together all unit operations, and an associated PFD for each of the identified scenarios. They are set up such that the various scenarios are produced simply by slightly altering the base case and reviewing their effect on Internal Rate of Return (IRR). A financial model will be created for the project to facilitate the client’s evaluation of alternatives and sensitivities. If the IRR for the process does not make the project profitable, the development work is terminated. The selection is usually made from

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many design alternatives on the basis of maximizing Net Present Value (NPV). The conceptual design activities are compiled into deliverable, known as the project specification, which supersedes the PBD at the end of the phase.

The Conceptual Design Process

Process Engineers

Initial Equipment Layout/ Arrangement Civil/Structural Layout/MTO, Piping Layout/MTO

Layouts Engineers with Input from Civil/Str. & Piping Engineers Basis for Design Process Flow Scheme (PFS) together with Heat & Mass Balance (H&MB)

Corrosion & Materials Engineers

Material Selection Report

Sizing of Equipment, Packages & Electrical Routing

Major Equipment Engineers

OPEX & CAPEX Estimates

Philosophies & Functional Specifications of the defined

and the initial Equipment List

Project Specification

Control & Instrumentation & Other Disciplines

Manpower & Services Estimate Weight & Volume Estimates

Figure 5.2.9 Conceptual Design Process.

The above conceptual design process schematic (Figure 5.2.9) indicates that the process engineers develop the Process Flow Scheme (PFS) or P&ID, together with the Heat and Mass Balance and the initial Equipment list. The Heat and Mass Balance is used to develop the Materials Selection report and the major equipment packages. At this stage, all units and equipment selected are checked for materials compatibility to certify they can withstand long-term exposure to the fluids (chemicals) they will come in contact with. The piping and layout specialists prepare the initial layouts, together with input from civil/structural engineers. Once an acceptable layout has been achieved, estimates are prepared to generate the operating expenditure (OPEX), capital expenditure (CAPEX) and availability forecasts. After the conceptual/basic process design, engineers would carry out conceptual/basic loss prevention and environment (LPE) or safety and loss prevention design studies (more recently called safety engineering, see Table 5.2.1). This is to determine those environmental regulatory features which must be addressed during the front-end engineering design

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and again to determine at this stage if the concept is viable. Also, major problems or constraints which must be overcome before concept can be said to be a viable project are identified at this stage. Conceptual/basic LPE study question as Crawley (2014) [70] puts it is, “basically, are there any ‘show stoppers’ which are so insurmountable that it is not worth carrying on with the Project?” The following table shows the list of deliverables from conceptual and basic process engineering design.

Conceptual

Basic Process

Table 5.2.1 Conceptual & Basic Process Engineering Deliverables. Process

Loss Prevention & Environment

• H&M balance of primary/secondary systems • PFD of primary/secondary systems • Utilities balance • Item list/equipment summary • Process data sheet for equipment & critical valve • Functional spec of packages systems • Equipment estimated consumption • Preliminary electric loads list & load balance • P&ID • Piping sizing • Metallurgical flow diagram • Spec for catalysts, chemical & inert materials • Process description • Risk analysis report • HAZOP report (basic) • Preliminary flare load • Preliminary layout for marine and seawater systems

• Definition of loss prevention criteria & philosophies • Environmental philosophy definition • Active fire protection system design basis • Preliminary safety analysis • Preliminary environmental analysis and studies

• Philosophy of preliminary/ secondary systems in relation to feasibility & costs • Primary/secondary systems definition • Identification of constraints and surrounding conditions for layout • Block flow diagram, characteristics of feedstock/products, prelim.

• Definition of loss prevention criteria & philosophies • Environmental philosophy definition • Active fire protection system design basis • Preliminary safety analysis • Preliminary environmental analysis and studies

Basic Engineering

Materials Corrosion & Welding

• Corrosion rate evaluation • Corrosion control philosophy • Material selection philosophy • Preliminary material selection diagrams

Loss Prevention & Environment

• Hazardous area classification d/s & layout drawings • Fire & gas detection schematic layout drawings • Fire proofing layout drawings and list of fire potential source

Table 5.2.2 Basic Engineering Deliverables.

• Design criteria for equipment & packages • Design spec for equipment & packages

Equipment • Design criteria for piping layout • General layout • Piping layout system design spec. • Methods for plants protection

Plant Layout & Piping • Design criteria for concrete structures, foundations & steel structures • Design criteria for civil and marine works

Civil Works • Package electrical equipment spec. • General single line diagram • Preliminary electrical system layout, substation location & main cable runs

Electrical Systems

(Continued)

• Design criteria for instr. Automation & telecom systems • Spec for design of instr. Automation & telecom system

Instrument Automation & Telecoms

Design and Chemical Engineering Practice 183

• Firefighting system master plan • Safety studies/ risk analysis • RAM analysis • Environmental studies

Loss Prevention & Environment

Materials Corrosion & Welding Equipment

Table 5.2.2 Basic Engineering Deliverables. (Continued)

Basic Engineering

Plant Layout & Piping • Design criteria for buildings and HVAC systems • Definition of building distributed functional layouts • Initial MTOs and BOQs/ Bill of engineering measurement & evaluation

Civil Works • Spec for electrical system installation • Basic calculation studies

Electrical Systems

Instrument Automation & Telecoms

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Furthermore, the various engineering disciplines (specialist engineers) prepare philosophies and functional specifications of the defined systems, which are compiled in the project specification. The objective of the project specification is to provide a detailed description of the essential project hardware, such that it can be used as part of the tender documentation for the execution phase of the project—the FEED and detailed engineering phase. Additionally, the various engineering disciplines (specialist engineers) prepare philosophies and functional specifications of the defined systems, which are compiled in the project specification. Other engineering disciplines (specialist engineers) likewise would prepare philosophies and functional specifications of the defined systems, which are compiled in the deliverable known as project specification. The objective of the project specification is to provide a detailed description of the essential project hardware, such that it can be used as part of the tender documentation for the execution phase of the project, which is the FEED and detailed engineering phase. The outcome of the basic engineering phase is a process flowsheet with estimated equipment sizes, process operating conditions, and flow rates for all the streams. New intellectual property is generated to protect the final manufacturing scheme and all economically feasible alternatives that have been identified, as well as new catalysts, compositions of matter, operating conditions, etc.

5.2.3.3 Front-End Engineering Design (FEED) After conceptual studies, the owner company would typically award a front-end engineering design (FEED) contract to an engineering firm or an EPC contractor. FEED is the work necessary to produce quality process and engineering design and documentation of ample depth, defining the project requirements for detailed engineering design, material procurement, fabrication and erection of facilities, and supporting a ±10 percent project cost estimate. It consists of producing P&IDs, MTOs, layouts, isometrics, etc., a level III schedule and most importantly a Tender Package for the EPC Contract. To achieve this cost reduction during FEED, a value engineering is conducted on critical aspects of the project to seek alternative ways of achieving a better function or cost reduction. After this phase, the full investment decision (FID) gate can then either be approved or unapproved by the owners and partners. FEED package refers to a completed process design package that includes all the necessary information required by an EPC contractor to perform the detail engineering of a

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process plant (details such as a structural steel supports, buildings, wiring, instrumentation and control details, piping details, insulation, equipment vendor/model selection, etc.). FEED is critical to the long-term success or failure of a process plant. If things are not done right at this stage then the project is in trouble no matter how good the subsequent engineering, construction, and project management work are executed. Timeline for this phase ranges between 6-12 months duration with a wide range of scope and cost. Activities of the FEED are more than 50% process engineering. Process design deliverables serve to define the entire engineering design and the principal process engineer ensures that the design components fit together. The deliverables are useful in communicating ideas and plans to other specialist engineers involved with the plant design, to equipment vendors, to external regulatory agencies and to construction contractors. The information/data received from the process department which is used as an input to other design activities include the fluid list, the process flow diagram (PFD) and the P&ID, specifications, process data and so on (refer to Table 5.2.3 to see full list of process deliverables at FEED). The fluid list is a document that contains information for the fluid to be carried along streams; the required material for producing the process pipe (not the precise properties or composition); the pipe’s corrosion allowance and the maximum service pressure and temperature. Again, loss prevention and environment (LPE) or Safety and Loss Prevention design (more lately called safety engineering) is an essential element in the FEED scope. Specialist chemical engineers in this area draw design input information from process design deliverables, especially the P&ID. The objective at this stage of the project is to ascertain solutions to design issues and if proper to perform the preliminary risk analysis and assessments. All the major problems and constraints identified in the concept phase are designed in the safety features at this stage to make sure risks are “as low as sensibly practicable”. It is essential to get the process fundamentally right from the start. The design is carried out to eliminate hazards rather than control it. Hence, specific systematic safety checks are usually incorporated in the design process at each level. This is generally termed hazard identification and assessment studies. Furthermore, as stated above, process design data governs other engineering designs. For example, process data on hydrocarbon constituents (pressure, temperature, poisons, PH, etc.), weight constraints, external environment and other information are used to select the materials of construction for piping and static or rotating equipment. The material selection diagrams (MSD) hence created subsequently, are used to supply

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material selection and corrosion allowance details in piping specifications and on equipment data sheets. The FEED scope will also include the plant’s instrumentation and automation design. To achieve this, transmitters such as flow, temperature, pressure and level instruments, relief devices and control valves are specified. Preliminary In/Out (I/O) count, which is vital to support the correct sizing of the Integrated Control and Safety System (ICSS) will be carried out. Also, the instrumentation, automation and control system philosophy, as well as the instrumentation requirements for package equipment vendors, would form part of the FEED package. 3D model review of the plant’s constructability is carried out during this phase (see Figure 5.2.11). Finally, assuming the project is considered worthwhile, P&IDs, equipment specifications, and a cost estimate of the new commercially designed process is generated. The FEED package is then ready to be handed over for detail engineering, procurement, and construction (EPC). Traditionally, a company may decide to source for a specialist EPC contractor that will handle the detailed design and construction phase. Refer to the case history related to development of a new chemical process in section 5.6.

5.2.3.4 Description of the Key Process Engineering Deliverables/ Activities Some of the key process engineering deliverables and activities produced and performed during conceptual, basic and FEED phase are described in this section. They include block flow diagram, process flow diagram (PFD) or process engineering flow scheme (PEFS), 3D-CAD model review, process narrative, process simulation using software, mass and energy balance.

To Gas

Receive Gas from various wells and flow stations for processing

Remove Mercury in the gas

Hg Medium Pressure Gas

Figure 5.2.10 A Process Flow Diagram.

Filter dust from the Mercury Removal Unit

Dust

Scrub gas

Liquid to Liquid Receiver

Compress Gas to reduce the volume and increase pressure

Cool Gas to be delivered to liquefaction facilities

Front End

• Process design basis • Control & safety valve datasheets • Guidelines for operating manuals • Cause & effects • Fluid list • P&ID (IFD) • Blow down & flare system finalization • Electrical load balance finalization • Safeguarding memorandum

Process

• Finalization of HAC, fire & gas detection, & fireproofing • Active fire protection system technical specification & datasheets, P&ID, PFD, materials selection diagram (MSD) & plot plan • Safety studies • Risk analysis & assessments

Loss Prevention & Environment

• Material selection diagrams • Preliminary corrosion risk analysis • Definition of metallurgical requirements for material operating in special & critical services • General welding specifications

Materials Corrosion & Welding • Thermo. & fluid dynamic calculation • Equipment datasheet • Critical equipment purchase requisition • Critical equipment technical bid evaluation

Equipment • Mechanized P&IDs • Line list • Utility distribution P&IDs • Plant layout – plot plan, 3D model review (IFD) • Piping components spec. • Preliminary list of materials, pipes & supports

Plant Layout & Piping • Design criteria • General specification • Topographic/ bathymetric survey • Design study for critical item structures & foundations • On-shore & marine soil investigation • Standard drawings

Civil Works • Electrical systems layout, substation and main cable run • Functional spec. for electrical control & monitoring system • Spec and sheets of electrical equipment

Electrical Systems

(Continued)

• Instrument list • Definition of instrument vessel connections • Preliminary sizing of control/safety valves & flow devices • Instrument main cable runs • Definition of control & safety systems (DCS, ESD, FGS) • Preliminary In/Out (I/O) list

Instrument Automation & Telecoms

188 Introduction to Chemical Engineering

Front End

• Instrument datasheet Control start-up & shutdown philosophy layout for marine & seawater systems finalization • Support to HAZOP & SIL analysis • Chemical & catalyst summary

Process

• Environmental impact studies follow up • Environmental permit documents follow up

Loss Prevention & Environment

Materials Corrosion & Welding Equipment • Underground networks basic layout • M/R for UG

Plant Layout & Piping • Design study of roads & sewers, pilling/soil improvement demolition, grading/ dredging • Architectural definition of buildings • Functional & mechanical definition of HVAC systems • Design study of civil marine works • Front End

Civil Works • General protection & metering diagram • Typical mounting details

Electrical Systems

• Definition of advanced process control • Definition of telecom systems • Block diagram of telecom systems • Definition of data base requirement & setup for instr., automation & telecom systems

Instrument Automation & Telecoms

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Development of Block Process Flow Diagrams (BFPDs) The preliminary flowsheet sketch in process design stage or conceptual stage, as the case may be, is known as block process/flow diagram or technical function flowsheets (TFFs) and consists of a series of blocks representing different equipment or unit operations that were connected by input and output streams. An example of a block flow process diagram is shown in Figure 5.2.10 and the process illustrated shows part of the process of gas treatment and compression prior delivery to liquefaction facilities and other users. The main objectives of the project being to: • Provide facilities to gather, process/treat, compress and meter gas supply to target users. • To achieve and or contribute to flaring down in the swamp area and Niger Delta area of Nigeria, so as to meet new Nigerian environmental standards which are against the disposal of gas by flaring. • To optimize the use of gas in the land and swamp areas so that gas can be transported by the integrated gas network from areas of production (low demand) to areas of utilization (high demand). In developing block flow diagrams (BFDs), the concept is usually to focus on the technical purpose of each step in the process, rather than specific unit operations or equipment types. The resulting block diagrams help to slow the tendency to go into design specifics until all possible options have been largely considered. Technical function descriptions are verb-object combinations, rather than nouns usually used to describe process unit operations. For example, in the case of the gas processing facility process, technical function phrases could be: “Receive gas from various wells and flow stations for processing”, “remove mercury in the gas”, or “compress gas to reduce the volume and increase pressure”. These descriptions are deliberately less specific and more generalized than the descriptions of unit operations that could fulfill those technical functions, such as pig receiver, mercury removal column, or gas compressor.

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3D-CAD Model Review For commercial plant or complex facility, it is hard for individuals to have a clear view from drawings of what the finished facility will look like, and how the individual disciplines input will interact. As a result therefore, the use of models, either physical or electronic, is often applied during conceptual design. A commercial 3D-CAD system is in vogue; hence it is now possible to replace the physical model with a computer-generated model with a walk-through facility. A 3D-CAD model presentation for a group of people is performed using a large projection screen having a high resolution (see Figure 5.2.11). The objective of such a model is to allow all disciplines involved to verify whether sound design criteria have been observed with respect to safety, constructability, operability and maintenance, for example, accessibility (particularly for maintenance), provision of adequate lifting capability, provision of laydown areas, location of main valves, location of critical process instrumentation, location of columns, heat transfer equipment, reactors, storage tanks, heaters, pumps and so on; routing of piping to suit the process, location of emergency stations, main piperacks, safe locations of vents and drains, location of waste effluent treatment system, location of fire protection and fire-fighting equipment. Also, other aspects analyzed during initial (conceptual) 3D model review include hazard assessment and associated methodologies and tools – including key health and safety aspect and key environmental aspects.

Figure 5.2.11 A Computer-Generated Model for a New Gas Central Processing Facility (CPF) (taken by the author during a Constructability Review at Aberdeen, UK).

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The Process Flow Diagrams (PFDs) with Heat & Material Balance The process flow diagram (PFD) represents a major step up from the BFD in terms of the amount of information that it contains. It contains the bulk of the chemical engineering data necessary for the design of a chemical process. The PFD shows the order of the unit operations (the equipment) and any recycle streams. What distinguishes the PFD from the BFD is that all the flows, temperatures, pressures, and so on, that enter, or exit a piece of equipment, are defined. Process flow diagram (PFD) development is central to the design task. It depicts the process route, showing the flows of material and energy between those process units that make up the plant. It therefore: • Defines the role (task) and operating conditions of each section or unit in the process line, • Allows an understanding of the overall operability of the process, • Provides an initial assessment of potential sources of hazards, • Forms the template for subsequent heat and mass balances, and • Gives an overall view of the process route. In general, PFDs typically follow this accustomed format: • Streams enter at the top left of the first page and leave on the right side of each sheet; • All equipment items are represented in sequence and connected by lines representing the piping; • Major process utilities are indicated in terms of where they are used in the process; • Process lines are called streams and each one carries a unique number for reference - a diamond shape is typically used; • Equipment is represented symbolically by “icons” that identify specific unit operations; • Each equipment item on the PFD has a unique equipment item number, and a corresponding equipment

Design and Chemical Engineering Practice







• • •

• • •



193

block summarizing such parameters as dimensions, material of construction, capacity, horsepower, design pressure and design temperature; The stream numbers also correspond to the stream summary in the heat and material balance (H&MB) in conjunction with the PFD; H&MB commonly accompanies a PFD giving the stream composition, flowrate, physical properties and thermodynamic properties; The equipment symbols identify the piece of equipment and are generally understood by all process engineers; Status of the PFD is shown in terms of revision number in the document’s revision table section; Normal, minimum and maximum stream values are provided for defined cases; Each H&MB represents a “case” whether it is normal operation, start-of-run conditions, end-of-run conditions, or a given product run; Process flow direction are also indicated; All utility streams supplied to major equipment that provides a process function are shown; Preliminary control instruments - basic control loops, illustrating the control strategy used to operate the process during normal operations, and A preliminary line size based on heat and material balance (H&MB) conditions are indicated on the PFD.

The PFDs produced will retain clarity of presentation, but the reader must refer to the flow summary and equipment summary tables to extract all the required information about the process. These symbols may differ slightly in various engineering firm. However, whatever set of symbols is used, there is seldom a problem in identifying the operation represented by each icon. Figure 5.2.13 contains some of the symbols used in process diagrams.

PFDs are usually printed on large sheets of paper (for example, 24 × 36 ) by a special printer known as a plotter (Figure 5.2.12).

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Figure 5.2.12 A Plot Printer (Picture sourced at; http://www.plotterwinkel.nl/hp-designjett730-36-inch-a0-printer.html, 2017).

Pumps, Turbines, Compressors

Furnace

Plate & Frame Heat exchanger

Horizontal and Vertical Storage tanks

Thermally Insulated Pipe

Packed Column

Heat Exchanger

Fan

Jacketed Mixing Vessel

Cooler

Cooling Tower

Fired Heater

Half Pipe Mixing vessel

Heater

Condenser

Centrifugal Pump

Reboiler

Centrifugal Compressor

Heater

PROCESS INPUT

VALVE

PROCESS OUTPUT

STREAM NUMBER

CONTROL VALVE

INSTRUMENT FLAG

GLOBE VALVE (MANUAL CONTROL)

Figure 5.2.13 Symbols for Drawing Process Flow Diagrams.

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Figure 5.2.14 shows that each major piece of process equipment is identified by a number on the diagram. A list of the equipment numbers along with a brief descriptive name for the equipment is printed along the top or below the diagram as is the case with PFD example below. Table 5.2.4-5 provides the information necessary for the identification of the process equipment icons shown in a PFD. As an example of how to use this information, consider the unit operations 6570-K-01E, 6570-V-01E and 6570-EA-01E. The first number means the unit area; the letter is the convention for identifying the equipment and the last number indicates that equipment is number 01 in unit 6570 (see PFD in Figure 5.2.14). This equipment numbering forms the process equipment tag number. Lines and instruments are not usually identified by tag. numbers.

Similarly, some connotations used for process instruments that are shown on a PFD include:

Table 5.2.4 Connotations Used for Field Instrument. PT Pressure Transmitter

TI Temperature Indicator

PC Pressure Controller

FC Flow Controller

PTD Pressure Transducer

FI Flow Indicator

TS Temperature switch

FIC Flow Indicator Controller

TC Temperature Controller

FCV Flow Control Valve

FI Flow Indictor

PIC Pressure Indicator Controller

PVC Pressure Control Valve

PCV Pressure Control Valve

LG Level Gauge

TT Temperature Transmitter

LR Level Recorder

LIC Level Indicator Controller

TS Temperature Switch

PIC Pressure Indicator Controller

TR Temperature Recorder

LT Level Transmitter

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Table 5.2.5 Conventions Used for Identifying Process Equipment. Process Equipment

General Format XX-YZZ A/B XX – are the identification letters for the equipment classification EA – After Cooler C – Column F – Furnace k – Compressor, Blower CN – Mercury Removal Bed E – Heat Exchanger H – Fired Heater G – Electric generator P – Pump R – Reactor T – Tower TK – Storage Tank LB – Liquid burner V – Vessel Y – designates an area within the plant S – Filter GT – Generator Turbines B – Boilers ZZ – is the number designation for each item in an equipment class A/B – identifies parallel units or backup units not shown on a PFD

Design and Chemical Engineering Practice HP Gas from a LP Receiving facilities HP Gas from a HP/LP Receiving facilities

197

Sales Gas to N-LNG FC

Chromatography

FC

Sales Gas to Power Plants

PC RC GAS BLENDING HEADER

To Gas Injection Unit 530

P1

HS

F1

P1

HS PC

FC

6430-CN-01

6570-K-01E LC

6570-EA-01E

Liquid to Liquid Receiver

6570-V-01E 6430-CL-01 ITEM DESCRIPTION

6430-CN-01

6430-CL-01

MERCURY REMOVAL BED

MERCURY REMOVAL DUST FILTER

6570-V-01E SALES GAS COMPRESSOR SUCTIONS RUBBER

6570-K-01E SALES GAS COMPRESSOR

6570-EA-01E SALES GAS COMPRESSOR AFTER COOLER

Figure 5.2.14 Skeleton Process Flow Diagram (PFD) Sales Gas Compressor unit (Flow summary not shown).

Also, utility streams are identified using letters. Utilities are needed services that are available at the chemical process plant. Chemical plants are provided with a range of central utilities that include electricity, compressed air, cooling water, fuel oil supply, refrigerated water, steam, condensate return, inert gas for blanketing, fire water, process water, potable water, chemical sewer, waste water treatment, and flares.

5.2.3.5 Process Narrative/Description For all equipment shown on the Process Flow Scheme (PFS), there should be a description and an indication of the key process data.

Process Description of the above PFD is as follows: Gas from crude oil flowstations is collected in an inlet manifold and passed through the High Pressure (HP) and Low Pressure (LP) gas receiving facilities to remove condensate collected in the pipelines. The gas receiving facilities consists of a Pig Receiver and sludge-catcher (see Figure 5.2.14). The gas from the receiving facilities passes through vessel 6430-cn-01 for mercury removal before undergoing compression.

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Compression consists of a high efficiency suction scrubber, compressor and after-cooler. The gas compressor is driven by a gas turbine. After compression, the gas is dehydrated in a common glycol contactor column. Dry gas is then metered for allocation purposes. The metering package includes gas chromatography and water dew point analysers. The metered gas passes through pressure control valves before entering Sales gas pipeline enroute N-LNG for liquefaction and export. Fuel gas will normally be supplied from downstream of the glycol contactor but can also be supplied from the gas export pipeline for start-up. Prior to entering the gas turbines the fuel gas will have a coalescer/filter and a downstream heater to prevent condensate entry into the gas turbines. Condensate from sludge catcher and compression section will be stabilized in condensate flash vessel. The stabilized liquid normally flows to a flowstation surge vessels for onward pumping before being pumped into an oil export line.

5.2.3.6 PFD Review A PFD review, which is done as a group exercise, usually may include technical experts on process design, technical experts on process chemistry (also, catalysis or biology), process safety experts, static and rotating equipment design engineers, instrumentation and automation engineers (process control engineers), plant construction engineers, project engineers and operations engineers. A large print out (hard copy) of the PFD is pinned where the group can identify and mark any correction or comments. The PFD may run to several sheets of drawings. For chemical processes, the PFD usually begins with the review of the process chemistry and block flow diagram and the process design basis. This can then be followed by the review of the PFD starting from the input (feed) stream up to the output (product) stream. The process designer who is presenting the design meticulously explains every assumption or consideration made at each stage of the process. Questions are asked to challenge the design considerations and see if there are missing solutions. Some relevant generic questions that can be raised by the team may include (for the PFD in Figure 5.2.14): • Is there any heating or cooling necessary before feed is sent to the gas receiving unit?

Design and Chemical Engineering Practice

Figure 5.2.15 A Projected PFD (taken by the author during a process design review meeting at Celle, Germany).

• How do we efficiently evacuate sludge from the sludge catcher vessel? • What are the separations that occur in the mercury removal unit? • Did we account for the pressure drop across the safety relief device and the friction loses in the discharge line in sizing the pressure relief valve? Also, for a typical chemical processing plant, the team may ask: • What is the condition of the input materials at storage and how are they delivered to the process unit? • Is it necessary to pass the feed through a kind of process separator or filter for further purification? • Are there more sustainable utilities that can be used instead of what has been considered? • What is the basis of choosing reactor process conditions? • What side reactions can occur? • Does the catalyst used undergo deactivation and what form of regeneration is required? • What are the chemical compositions and concentrations of effluents being discharged to the environment? • What is the reliability of the safety features in the process?

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Heat and Material Balance Heat and material balance is also referred to as energy and mass balance. It is essentially the application of the law of conservation of mass. Developing the H&MB is a critical aspect of PFD/PFS development. However, some engineers will like to separate the PFD from H&MB. The H&MB enables the process engineer to design the process equipment and piping indicated and helps the engineer to understand the thermal and mass transport values at various units in the process. Consequently, it must go beyond normal compositions, flows, temperatures and pressures, and provide additional useful information for extreme conditions that may be possible. To develop H&MB, possible scenarios to be considered are mapped out, such as the following: • • • • • • •

Normal case Startup case Shutdown case Startup run case End run case Product A, B through n cases Runaway case

Energy and material balance calculations are carried out by applying the mass balance equation and the energy balance equation to each process unit or equipment. Simulation software are also used to perform these calculations. H&MB information is summarized on a table also known as stream table. General parameters required are shown in Table 5.2.6. A sample of heat and material balance table calculated from upstream flowstation for oil and gas production using software is shown in the following Table 5.2.7. These steams represent a part of the hundreds of streams simulated, that is stream 1, 2,..........x.

Design and Chemical Engineering Practice Table 5.2.6 Required Information Provided in a PFD Summary. Stream Number Temperature (°C) Pressure (bar, KPa) Vapor Fraction Total Mass Flowrate (kg/h, Tonne/h) Total Mole Flowrate (kmol/h) Individual Component Molar Flowrates (kmol/h)

Table 5.2.6b Optional Information Provided in a PFD Summary. Component Mole Fractions Component Mass Fractions (Composition) Individual Component Flowrates (kg/h) Volumetric Flowrates (m3/h) Significant Physical Properties * Operating Density * Viscosity * Other Thermodynamic Data * Heat Capacity * Stream Enthalpy (KJ/Kgmole) * K-Values Stream Name

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Table 5.2.7 Information on a Heat & Material Balance Table. Stream No.

1

2

H2O

14,3241

51,6940

CO2

2,2080

0,9418

Nitrogen

0,1300

0,0908

Methane

71,9054

33,5671

Ethane

4,8303

2,9365

Propane

2,5035

1,9578

i-butane

0,6759

0,4986

n-butane

0,7031

0,5970

i-pentane

0,0507

0,1827

n-pentane

0,0585

0,2110

n-heptane

0,0000

0,0000

n-octane

0,0000

0,0000

n-nonane

0,0000

0,0000

n-decane

0,0000

0,0000

C7+

0,0000

0,0000

Property (Stream Component) Molar %

x

Units

Table 5.2.7a Information on a Heat & Material Balance Table. Stream No.

1

2

Overall Mass Flow

Kg/h

178852,67

324922,43

Molar Flow

Kgmole/h

8016,30

10973,61

Pressure

Bar_g

81,99

21,48

Temperature

C

29,00

29,00

Molar Weight

Kg/kmol

22,31

29,61

Heat Flow

Kcal/h

-232967708

-546490901

Vapor Fraction

Mol

0,81

0,38

x

Design and Chemical Engineering Practice Table 5.2.7b Information on a Heat & Material Balance Table. Stream No.

1

2

x

Vapor Mass Flow

Kg/h

124017,36

81789,31

Molar Flow

Kgmol/h

6467,04

4201,97

Std Gas Flow

MMSCFD

129,60

84,21

Molecular Weight

Kg/kmol

19,18

19,46

Compressibility

None

Cp/Cv

None

1,38

1,05

Mass Density

Kg/m3

79,44

18,65

Mass Heat Capacity

Kcal/kg-C

0,68

0,53

Thermal Conductivity

Kcal/m-hr-C

0,04

0,03

Viscosity

cP

0,01

0,01

Table 5.2.7c Information on a Heat & Material Balance Table. Stream No.

1

2

Light Liquid Mass Flow

Kg/h

34202,86

141046,83

Molar Flow

Kgmol/h

404,98

1106,56

Std Liquid Flow

Barrel/day

8523,79

33384,58

Molecular Weight

Kg/Kmol

84,46

127,46

Mass Density

Kg/m3

592,92

627,14

Mass Heat Capacity

Kcal/kg-C

0,59

0,57

Surface Tension

Dyne/cm

11,36

17,82

Thermal Conductivity

Kcal/m-hr-C

0,08

0,09

Viscosity

cP

0,35

0,57

x

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Table 5.2.7d Information on a Heat & Material Balance Table. Stream No.

1

2

x

Heavy Liquid Mass Flow

Kg/h

20632,4

102086,30

Molar Flow

Kgmol/h

1144,28

5665,08

Std Liquid Flow

Barrel/day

3068,34

15184,33

Molecular Weight

Kg/Kmol

18,03

18,02

3

Mass Density

Kg/m

1007,05

1005,06

Mass Heat Capacity

Kcal/kg-C

1,03

1,03

Surface Tension

Dyne/cm

71,36

71,38

Thermal Conductivity

Kcal/m-hr-C

0,53

0,53

Viscosity

cP

0,81

0,81

5.2.3.7 Chemical Engineering Equipment Descriptions for PFD and P&IDs The final element of the PFD/PFS is the equipment summary. This summary provides the information necessary to estimate the costs of equipment and furnish the basis for the detailed design of equipment. Table 5.2.8 shows the information (process parameters) needed for the equipment summary portion of PFD/PFS for most of the equipment encountered in fluid processes. Table 5.2.8 Equipment Summary Parameters. Column - Internal diameter and length between tangent lines - Operating pressure - Operating temperatures at inlet and outlet lines - Tray columns: Number of trays. Number the trays from bottom to top. Trays at which the feed or reflux enters or from which products or reflux are drawn are indicated with their tray numbers. Internals are shown schematically - Packed columns: Type of packing (random or structured), height and number of packed beds (Continued)

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Table 5.2.8 Equipment Summary Parameters. (Continued) Heat Transfer Equipment (unfired) - Total heat duty - Heat exchange surface area - Operating temperatures at inlets and outlets Vessels - Internal diameter and length between tangent lines - Operating pressure - Orientation - Total volume - Operating temperatures at vessel inlet and outlet - Approximate location of feed and draw-off lines - Internals, e.g., halfpipe, schoepentometer, demister (schematically) - Materials of Construction

Table 5.2.8b Equipment Summary Parameters. Reactors - Internal diameter and length between tangent lines - Total volume - Operating pressure - Operating temperatures at inlet and outlet lines - Jacket or internal heat transfer equipment, if required, with heating/cooling duty - Internals (schematically) Heat Transfer Equipment (fired) - Total heat duty - Type - Tube Pressure and Temperature (Continued)

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Table 5.2.8b Equipment Summary Parameters. (Continued) - Fuel - Material of Construction Mixers - Type of mixer - Capacity of mixer (kW input) Separators - Internal diameter and length between tangent lines - Special internals (schematically) - Number, type and design of plates

Table 5.2.8c Equipment Summary Parameters. Pumps - Actual operating capacity - Discharge pressure - Differential head in meters - Flow - Temperature - ΔP - Driver Type - Shaft Power (Efficiency) - Materials of Construction Compressors and Blowers - Actual operating capacity - Actual inlet flowrate - Temperature - Pressure (Continued)

Design and Chemical Engineering Practice Table 5.2.8c Equipment Summary Parameters. (Continued) - Driver type - Shaft power - Materials of construction Packaged Units and Miscellaneous Equipment - Relevant features (Provide critical information)

Table 5.2.8d Equipment Summary Parameters. Tanks - Pressure, Temperature - Maximum working volume - Internal diameter and height - Orientation - Special features, e.g., blanketing, mixing, blending, heating, etc. - Materials of construction Towers - Size (height and diameter) - Pressure - Temperature - Number and type of trays - Height and type of packing - Materials of Construction Heat Exchangers - Type: Gas-Gas, Gas-Liquid, Liquid-Liquid, Condenser, Vaporizer - Process: Duty, Area, Temperature, and Pressure for both streams - Number of shell and tube passes - Materials of construction: Tubes and Shell

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5.2.3.8 Detailed Process and Engineering Design This phase is for the development of all required construction drawings and documents up to the AFC (Approved for Construction) stage for the plant construction, and detailed bill of materials (BOM) for the bulk material procurement based on the front-end engineering design (FEED) package or specifications. This phase starts with the piping and instrumentation diagrams (P&ID) being issued for design (IFD). All major tagged equipment are defined and procured. The EPC contractor handling the detailed engineering design would normally subcontract design of process unit operations (tagged equipment) to specialist firms (usually made of chemical and mechanical engineers) who have the know-how to supply equipment, given their repeated experience in this area. The drawings and information produced by these specialists (known as vendors or sub-contractors) are then incorporated into the main P&IDs and other engineering drawings and documentations to produce the final plant construction drawings. Detailed engineering design work typically produces a large number of documents, drawings, specifications, tables, data sheets, purchase requests, budget accounting, and so on. All these documents are dated, numbered and categorized according to the various engineering specialties. The design group will consist of different specialists but the chemical or process engineer is the main technology provider in a process facility design. The team is usually on hand to provide continued engineering support during construction phase, to ensure design integrity and minimize cost of delay in construction. Upon full completion of the construction phase, chemical engineers who specialized in plant commissioning will commission, start-up and test run the plant.

Figure 5.2.15 A Complex Process Plant. Credit: Schlumberger.

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Process engineering in this phase among other activities will involve design and production of Piping and Instrumentation Diagrams (P&IDs) for all process and utility systems, process data sheets for equipment, functional specification for equipment, control requirement specifications (trip/alarm settings), safety requirements and plant operating procedures. Safety requirement will involve the design, identification and production of relief and blowdown philosophy, protective system (including fire) philosophy, hazardous areas and safety and environmental case. Loss prevention and environment (LPE) at detailed engineering design involve detailed design/specification of equipment, HAZOPs, review of overpressure protection or relief and blowdown, classification of hazardous area, detailed design of protective systems (active or passive) and others. Designing a safe chemical or gas plant is critical. Process engineers would hence ensure that any closed system in the proposed process plant which may be pressurized possibly beyond its equipment rating due to heating, exothermic reactions, or by certain pumps or compressors, are designed to have appropriately sized pressure relief valve included to prevent over pressurization for safety. Extensive analysis of these design parameters (temperature, pressure, flow rates, etc.) to ensure that the plant has no known risk of serious hazard are known as hazard and operability (HAZOP) or fault tree analysis. These activities are necessary to ensure that the detailed design is correct and has addressed all known problems identified in the previous phase and that the plant will operate, start up and shut down safely and efficiently. P&ID mechanization entail checking all P&ID piping details to ensure that all valve types conform to their location and piping material specification; identifying and removing redundant pipe sections, where necessary; examining and balance-checking line pressure/temperature rating or classes for all pipe sections; assigning assembly mechanisms for all instruments, taps, vents, drains and others connected to each pipe run in accordance with line class number, the corrosion allowance and the fluid; cross-checking unit numbers to or from individual pipes; ensuring that all pipe sections are isolatable and serviceable. This is achieved by checking that the number of blinds, valves and drains is adequate and that they are correctly located; reviewing the existence and selection of block valves on either side of the control valves and the fittingness of by-pass valves for the pipe section being controlled, etc. Details of Instrument/Civil/Electrical design are also carried out at this stage and relevant specifications and drawings produced for technical requisitions and bid evaluation and also the detail drawings for the plant construction. Details of deliverables arising from detailed design phase are shown in the following Table 5.2.9.







• • • •

• • •













• •



Finalization of HAC, fire & gas detection, & fireproofing Safety studies Active fire protection system technical specification & datasheets, P&ID, PFD, materials selection diagram (MSD) & plot plan Risk analysis & assessments Environmental permit documents follow up Equipment arrangement drawings



Process

Process design basis Equipment specification Guidelines for operating manuals Piping classification data Piping lists Line schedules Control & valves datasheets Cause & effects Fluid list P&ID (IFC) Blow down & flare system finalization Electrical load balance finalization Safeguarding memorandum Instrument datasheet

Loss Prevention & Environment









Material selection diagrams Corrosion risk analysis Definition of metallurgical requirements for material operating in special & critical services General welding specification

Materials Corrosion & Welding















Thermodynamics & fluid dynamic calculation Equipment datasheet Critical equipment purchase requisition Critical equipment technical bid evaluation Supply bills of materials Supply setting plans Detailed drawings for vendor’s shop detail drawings

Equipment

Table 5.2.8 List of Detailed Engineering Design Deliverables.

Detailed Engineering Design













• •



Mechanized P&IDs Line list Utility distribution P&IDs Plant layout – plot plan, 3D model review (IFC) Piping general arrangement drawings Piping components spec. Underground networks basic layout Full list of materials, pipes & supports M/R for U/G networks & prefabrication

Plant Layout & Piping













• •

Design criteria General specification Topographic/ bathymetric survey General arrangement drawing On-shore & marine soil investigation Detailed design drawings Design study of critical item structures & foundations Design study of roads & sewers, pilling/soil improvement demolition, grading/ dredging

Civil Works













Electrical requisitions Single line diagrams Electrical systems layout, substation location & main cable runs Spec & datasheets of electrical equipment Functional spec for electrical control & monitoring system Electrical tracking

Electrical Systems













(Continued)

Material requisition Definition of or detailed specs for control & safety systems (DCS, ESD, FGS, SGS) Instrument item list Definition of instrument vessel connections Instrument main cable runs In/Out (I/O) list

Instrument Automation & Telecoms

210 Introduction to Chemical Engineering

Detailed Engineering Design













Control start-up & emergency shutdown philosophy HAZOP studies & SIL analysis Chemical & catalyst & utility summary Process simulation report Chemical HAZOP summary HAZID report

Process

Loss Prevention & Environment

Materials Corrosion & Welding Equipment









Pipe erection & prefabrication data Spec for insulation, painting, coating & fire proofing protection Structure singleline drawings Isometric drawings

Plant Layout & Piping

Table 5.2.8 List of Detailed Engineering Design Deliverables. (Continued)











Architectural definition of buildings Functional & mechanical definition of HVAC systems Design study of civil marine works Final MTOs & BOQs Structural engineering

Civil Works











General protection & metering diagram Typical mounting details Standard installation drawings Lighting systems Electrical system design report

Electrical Systems

• • •











Sizing of control, safety valves, UPS & flow devices Definition of advanced process control Definition of telecom systems Block diagram of telecom systems Definition of data base requirement & setup for instr., automation & telecom systems Loop diagrams MTOs Cause & effect

Instrument Automation & Telecoms

Design and Chemical Engineering Practice 211

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The Detail Process/Piping and Instrumentation Diagram/Drawing (P&ID) During detailed engineering design, detailed P&ID is developed. This is the diagram that shows the details of the process flow piping together with the installed equipment and instrumentation. It is a pivotal document for the chemical plant engineering and construction project. The acronym is defined in several ways. It is sometimes defined as process and instrumentation diagram and in other case as piping and instrumentation diagram. Sometimes also the diagram is replaced with drawing. The P&ID includes instruments, valves, minor pipelines, line sizes, etc. Both PFDs and P&IDs are required, each serving a unique need at a given time. A PFD, with its attendant energy and mass balance (H&MB) as explained above, provides the relevant details about process flows and compositions to support economic decisions made in the early front-end loading phases. The P&ID provides a summary of every plant unit in sequential order. It contains the information and references required to define every engineered process equipment item, process piping item or specialty item. P&IDs also play a significant role in the maintenance and modification of the chemical process that it describes. The document is therefore critical to demonstrate the physical sequence of process equipment and systems, in addition to how these systems connect. During the detailed design stage, the diagram also provides the basis for detailed development of system control schemes, allowing for further safety and operational investigations, such as the hazard and operability study (HAZOP). Hence, it illustrates the measurement devices that provide inputs to the control strategy, the actuators that will implement the results of the control calculations, and the function blocks that provide the control logic. Process and instrumentation diagram (P&ID), typically shows: • • • • • •

Process Piping and instrumentation details Process control and shutdown schemes Mechanical equipment with names and numbers Safety and regulatory requirements Pipe specifications or line numbers Process control instrumentation beyond the primary element and related valve, • Minor process lines,

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213

• • • • • • •

Process safety valves (PSVs) and their identifications, Other minor piping and process details; Interconnections references Flow directions Permanent start-up and flush lines, Basic start up and operational information, Identification of components and subsystems delivered by others, • Miscellaneous such as vents, special fittings, drains, double blocks and bleeds, sampling lines, reducers, increasers and swages. An extract of a portion of P&ID in a gas blending and compression plant is shown in the following Figure 5.2.16.

To Unit 2710 HP Elevated Flare Header

To Unit 3570 from HP Sales Gas Compressor From Unit 4130 Mercury Removal Unit

To Close Drain

Figure 5.2.16 P&ID of Gas Blending and Mercury Removal Unit of a Gas Plant in Nigeria.

Note: Refer to Figure 5.2.14 and compare features of mercury removal bed and mercury removal dust filter with those on the above Figure 5.2.16, to see difference between PFD and P&ID.

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214

Figure 5.2.17 Construction of the Gas Blending & Mercury Removal Unit of a Gas Plant in Nigeria (See P&ID in Figure 5.2.16).

HG–4250–019–2”–D03–V

1”

LG 001C

P

SEE DETAIL “A” H LT

I

P P

L I

2” P

1” P

24” 24”

O TW 001

TI 001

N4

CN4

M1

24” N7A

N2

M4

2” N1B

CN5

2” N5

4250–VQ–01/1 LAHH:+300mm N8A 24”

LT 003

N7B

I M3

24” 2”

I LG 001A

I

½”

O

24” N1A

CN2A 2”

LG 001B

1” P

HG–4250–033–24”–D03–V

O

O CSO

L MV

PT 004

2” CN1A

H

SYMMETRICAL PIPING

2”

1”

P

PIC 004

I

2”

001

O

I

P

I

HG–4250–021–4”–D03–V

O

ESD

3/4” I

HH L LL

O

LI 003

28 86

O

HG–4250–002–24”–D03–V

O

FROM UNIT 4250 SWAMP GAS PIG RECEIVER DWG No. DPFM. 12301

CSO

24”

N8B

4250–VQ–01/2

24”

LAH:+800mm

M2

LAL:+500mm

CN2B CN1B

LALL:+300mm

N6

N10

N9 N3

2” STEAM OUT

3”

2”

1”

CO–4250–001–2”–D03

Figure 5.2.18 P&ID Showing a Swamp Gas Sludge Catcher Unit of a Gas Plant in Nigeria.

Figure 5.2.19 shows construction of sludge catcher—a separator that can absorb sustained in-flow of large liquid volumes at irregular intervals.

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Figure 5.2.19 Construction of the Gas Sludge Catcher Unit of a Gas Plant in Nigeria (See P&ID shown in Figure 5.2.18).

Process Equipment Furthermore, during detailed engineering design, the materials of construction for important process equipment are identified.

Factors considered when selecting material of construction include: - Mechanical properties such as tensile strength, hardness, fatigue, toughness, creep resistance, toughness - Corrosion resistance - Oxidation resistance - Standard size availability (plates, sections, tubes) - Tendency to form spark - Cost - Ease of fabrication – ductility, weldability, castability - Chemical compatibility - Temperature stability - Any special properties required such as magnetic properties, electrical resistance, thermal conductivity

Also, detailed mechanical and equipment design is carried out to arrive at reasonably accurate equipment sizes, and more simulations are performed at

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this stage. The detailed mechanical equipment design is usually performed by chemical engineers in collaboration with static equipment engineers (a specialty for chemical or mechanical engineering graduates) and rotating equipment engineers. Process equipment consists of processing (static and rotating), manufacturing, handling, inspecting, storing, and transporting raw materials and finished products. Process equipment may also consist of extruding, casting, heat-treating, molding, rolling, forging, compacting, and other process equipment and components used for metals processing, polymers or other materials. The equipment used in chemical processes industries can be divided into two classes: the proprietary and non-proprietary. Proprietary equipment such as pumps, compressors, filters, air conditioners, centrifuges and dryers, is typically designed and manufactured by specialist firms. Non-proprietary equipment is designed as special, one-off items for a given process unit: for example, reactors, cyclone, distillation columns, absorption columns, heat exchangers, separators and other pressure vessels. These are usually referred to as chemical engineering equipment. The chemical or process engineer’s role in the design of “non-proprietary” equipment is usually limited to selecting and “sizing” the equipment. For example, in the design of a distillation column the chemical engineer will typically determine the number of plates; the type and design of plates; diameter of the column; and the position of the inlet, outlet and instrument nozzles. (See chemical engineering equipment design specifications in Table 5.2.8.) Chemical process design engineers designed, for example, the mercury removal unit equipment shown in Figure 5.2.17, to determine the nozzle location, inlet and outlet location, diameter of the column and number, type and design of plates. An example of detailed static equipment sizing technique by chemical engineers can be seen in section 5.4. The equipment design specification derived by chemical engineers would then be transmitted, in the form of specification sheets, to the specialist mechanical design group, fabricator’s design team, who will go further to produce the equipment detailed fabrication drawings. Some chemical engineers, as explained above, can also specialize in this area, which is usually the domain of mechanical engineering specialists. Reliable estimates of the capital and operating costs for equipment are usually determined based on quotes submitted by these specialist mechanical equipment manufacturing companies (vendors). Ideally the vendors are usually requested to quote cost and fabrication timeline of any given equipment, during the FEED stage. Additional request for quotation will be issued to vendors during the detailed engineering design. Usually, at least three vendors are invited to quote and they will be technically and commercially evaluated. A successful vendor will be selected and awarded the contract to manufacture and supply the equipment to the main engineering,

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Figure 5.2.20 Sales Gas Compressor – An Example of Proprietary Equipment.

procurement and construction (EPC) contractor. The outcome of detailed engineering design phase is a technology package suitable for handing off to a construction team for actual plant construction and commissioning.

5.3 Construction, Pre-Commissioning, Commissioning & Startup The chemical or process plant construction, Pre-commissioning, Commissioning & Startup, can be done either by the same detailed engineering contractor, otherwise known an EPC company or be contracted out by client COMPANY to a dedicated construction company. Most plant construction companies do have detailed engineering design capability. Economic considerations and other factors may inform the choice of client COMPANY in selecting one or more than one contractor for an EPC project. This phase of the chemical and plant development involves fabrication and erection of equipment, piping, instruments and cablings. Precommissioning includes final checks of the construction matching the P&ID and other drawings. Motor rotation, check valves facing the correct direction, electrical loop checks, electrical terminations, piping matching the piping codes, all need to be reviewed. Commissioning involves nitrogen introduction into pipes (purging and inerting), rotating equipment running for 72 hours uninterrupted, leak and pressure test, flushing, chemical and mechanical cleaning, drying out and so on. Chemical engineers who specialized in plant commissioning are appointed to drive this phase of the project. The overall objective of commissioning is to ensure that a process plant is brought into full production without risk to the personnel, the environment and the equipment. For an oil and gas processing plant construction, there

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are acceptable industry list, such as API publication 700 – “Checklist for Plant Completion,” which shows a general procedure for commissioning and safe hydrocarbon introduction. Startup is the final step to completing the project.

Figure 5.3.1 An ongoing process plant construction site.

5.4 Case Study of Chemical Engineering Equipment Design – Horizontal KOD Liquid-Vapor Separator Background A knock-out drum separator is installed as part of a closed pressure-relief system to remove entrained liquids from a multiphase stream being discharged to the flare. This section considers the requirements and steps taken to size a flare horizontal knock-out drum separator from first principle, at the right limits. It describes those scientific principles applied, the concept of closed pressure-relief system and the role of a knock-out drum separator in the system. A case design based on the approach used in sizing a flare horizontal knock-out drum for gas processing plant, which meets conventional requirement for optimal solution, is explained.

5.4.1 Introduction A closed pressure-relief system controls over-pressurization of process units by relieving the vapors to the flare, which destroys hydrocarbons in

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a high-temperature flame. The flare, in addition, takes care of gas discharge due to plant or partial plant start-ups or shutdowns and planned combustion of gases over a period of time. Over-pressurization can occur in a chemical or gas plant as a result of general power failure, cooling water failure, instrument failure, external fire, automatic control failure or blocked outlet. Failure of pressure-relief system can be catastrophic (see examples in Figure 5.4.1). A Flare Knock-out drum (KOD) separator is part of a closed pressure-relief system which is installed to separate liquid from vapor in order to: • Prevent discharge of liquid hydrocarbon to the atmosphere, incomplete combustion, smoking, burning rain. Hence, save the human environment from disaster. • Prevent pulsation (disturbing rhythmic noise) of flare input gases, causing interruption of the flare. • Reduce flare capacity requirements. • Serve as liquid recovery and storage vessel.

April 1, 2003, an over-pressurized process vessel in Kentucky got ruptured killing one person (source:www.csb.gov/d-dWilliamson-and-co-catastrophic-vessel-failure, April/, 2007)

June 13, 2013, an over-pressurized reboiler unit of William Olefins Plant (Louisiana) got ruptured and exploded, killing two employees (Source: www.ehstoday.com/safety/poorprocess-safety-culture-Williams-olefins-plant-contributed2013-explosion-killed-two-empl, April, 2007)

Feb 18, 2015 – a large explosion at ExxonMobil’s refinery in California due to over-pressurization, it sent irritating ash to the surrounding neighborhood (Source: www.latimes.com/local/lanow/la-me-In-exxon-mobil-refinery-blast-20150223-story-html, April, 2007)

Figure 5.4.1 Accidents due to over-pressurization of process units.

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KOD is one type of gas/liquid separators which is used particularly for separation of liquids carried with gas streams flowing to the flares in oil, gas and petrochemical (OGP) plants. It is a vessel being designed to handle streams with high gas-to-liquid ratios. The liquid is generally entrained as mist in the gas or is free-flowing along the pipe wall. Hence, the KOD is used to slow gases and allow liquids to “fall out” of the gas stream. KOD separators can be used in other ways, for example, where a gas stream flows into a compressor suction of a plant, a KOD can be installed to prevent liquid from entering the compressor. KODs can also be installed in process units to prevent gaseous condensation in flare header as illustrated in Figure 5.4.2. The main difference between flare KODs and other conventional gas/liquid separators lies in the size of the droplets to be separated, i.e., separation of 300-600micron (um) droplets fulfills the requirements of flare gas disengagement. Therefore, usage of a mist eliminating device may not be necessary in flare KODs except for cases where the results of calculations lead to an abnormally large drum size. In such cases, application of vane type or multicyclone separators may help to avoid employing an extremely large drum. Main Flare Header

Flare Header Safety Valves 1st Unit

Safety Valves 2nd Unit

Safety Valves nth Unit

KO Drum Process Units • Can allow carry over of large liquids droplets (above 600 um) • Not mandatory but can be installed to prevent condensation in flare header

Flare Unit KO Drum • Cannot allow carry over of large liquids droplets (above 600 um)

Figure 5.4.2 Schematic of a closed pressure-relief system.

This schematic emphasizes the stream that goes to the flare only.

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5.4.2 Knock-Out Drum Separator Design In this case study, a flare KOD separator shall be designed (sized) from first principles. The sizing method applied herewith complies with API (American Petroleum Institute) 521 design rules.

5.4.2.1 Scientific Principles Applied Three principles used to achieve physical separation of gas and liquids or solids are momentum, coalescing and gravity settling. The fluid phases must be “immiscible” and have different densities for separation to occur though any separator may employ one or more of these principles. Momentum Fluid phases with different densities will have different momentum. If a two-phase stream changes direction sharply, greater momentum will not allow the particles of the heavier phase to turn as rapidly as the lighter fluid, so separation occurs. Momentum is usually employed for bulk separation of the two phases in a stream. In the KOD separator, the initial gross separation of liquid and vapor occurs at the inlet diverter. Fluid that enters the separator hits the inlet diverter, causing an abrupt change in momentum. The liquid droplets fall under gravity to the bottom of the vessel where it is collected. This liquid collection section provides the retention time required to let entrained gas evolve out of the oil and rise to the vapor phase. Coalescing Coalescing devices in separators force gas to follow a tortuous path. The momentum of the droplets causes them to collide with other droplets or the coalescing device, forming larger droplets. These larger droplets can then settle out of the gas phase by gravity. Before the gas leaves the vessel, it passes through a coalescing section or mist extractor (where required). Coalescing devices such as elements of wire mesh screens, vane elements, and filter cartridges or plates, are used to coalesce and remove the very small droplets of liquid in one final separation before the gas leaves the vessel.

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Gravity Settling Liquid droplets will settle out of a gas phase if the gravitational force acting on the droplet is greater than the drag force of the gas flowing around the droplet (see Figure 5.4.5). Vapor/liquid separation in a KOD are usually accomplished in three stages: • Primary Separation, momentum of entrained liquid in the vapor causes largest droplets to impinge on diverter and drop by gravity. • Secondary separation, gravity separation of smaller droplets as vapor flows through disengagement area. • Final separation, smallest droplets coalesce to form mist which will separate by gravity. The following Figure 5.4.3 illustrates the three stages of separation in a KOD.

Primary Separation

Secondary Separation

Vapor

Vapor Space D Max Liquid Level

Final Separation L

Figure 5.4.3 Stages of Vapor/Liquid Separation.

For a three-phase separator, the configuration will be as shown in Figure 5.4.4.

Design and Chemical Engineering Practice Pressure releases

Well Fluid Inflow

Mist Extractor

Gas Outflow

Natural Gas

Emulsion Layer

Mist

223

Max Liquid Level

Water Overflow Baffle

Water Outflow

Oil Outflow

Figure 5.4.4 Three-Phase Separator. Drag force of gas droplet

Liquid Droplet

Gravitational force on droplet

Gas Velocity

Figure 5.4.5 Forces on Liquid Droplet in Gas Stream.

The forces acting on a particle can be described mathematically using the terminal or free settling velocity:

Vc

2g Mp( l

v

l

A pC

v

(5.4.1)

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Introduction to Chemical Engineering

4 g D( l 3 vC

Vc

v

)

(5.4.2)

Where g = acceleration due to gravity, Mp = mass of droplet or particle, lb or kg, D = droplet diameter, ft or m, l = liquid phase density, lb/ft3 or kg/m3, v = vapor phase density, lb/ft3 or kg/m3. Also, Vapor density, v is given by,

v

P( MW ) RTZ

(5.4.3)

P = system pressure, MW = molecular weight The drag coefficient is a function of the shape of the particle and the Reynolds number of the flowing gas. Particle shape is considered to be a solid, rigid sphere for the purposes of this equation. The Reynolds number is defined as:

R

1, 488D Vt

v

(5.4.4)

In this form a trial and error solution is required since both particle size, D, and terminal velocity, Vt , are involved. To avoid trial and error, values of the drag coefficient are presented in Figure 5.4.10 as a function of the product of drag coefficient, C, times the Reynolds number squared; this technique eliminates velocity from the expression. The abscissa of Figure 2.3.5 is given by:

CRe2

0.95 108

v

D3( 2 v

l

v

)

(5.4.5)

Flare KO drum may be horizontal or vertical. Usually, installation and economic consideration determines whether horizontal or vertical KOD separator will be required. When large liquid storage is required and vapor flow is high, a horizontal drum is often more economical.

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5.4.2.2 Design Parameters The following major parameters shall be carefully determined before starting the KO drum design: • Operating pressure in case of relief due to over-pressure • Maximum allowed diameter of liquid droplet in the separated gas • Design Pressure • Liquid hold-up volume • Design Temperature • Length to diameter ratio for horizontal drums • Flow rates • Physical properties of the streams • Degree of separation required Operating Pressure The separator operating pressure corresponds to the back pressure. Back pressure is the pressure that exists at the outlet of a pressure relief valve as a result of pressure in the discharge system. Operating pressure in other words is the pressure in the equipment when the plant operates at steady state condition, and this is subject to normal variation in operating parameters. HP flare KOD separator will typically have operating pressure ranging between 4 to 7 barg for the maximum gas relief case; LP KOD separator operating pressure does not generally exceed 1 to 2 barg. Maximum Allowed Diameter of Liquid Droplet The minimum size diameter droplet typically is in the range of 150 to 2,000 microns (one micron is 10-4cm or 0.00003937inch). 150 microns will be used for this sizing calculation (see Table 5.4.3). Design pressure Design pressure is the maximum internal or external pressure that will be used to determine the minimum permissible wall thickness of the separator. The table below gives the margin to be applied on the maximum operating pressure to determine the separator design pressure. It should be noted that the above table does not apply to storage tanks, atmospheric tanks and pipelines. For systems protected by a pressure

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Introduction to Chemical Engineering Table 5.4.1 Determination of the separator design pressure. Operating pressure OP (barg)

General case Minimum design pressure (barg)

10

OP + 10%

safety or relief valve (PSV), the minimum design pressure of 3.5 barg will correspond to the set pressure of the valve. With a balanced PSV, the maximum allowed back pressure at the PSV discharge in case of release will be 1.75 barg (50% of the set pressure); with a conventional PSV, the maximum compatible back pressure is 0.35 barg (10% of the set pressure). Liquid Hold-up Volume The emergency liquid hold-up volume of the separator shall be 20 minutes of the maximum liquid relieving case, as per API 521. Design temperature Similarly, the design temperature is the temperature of the separator equipment. This is calculated putting with due consideration of the special cases such as depressurization, usage of steam for drum cleaning, start-up and shutdown conditions, and so on. The maximum design temperature is given as operating temperature +15°C or black body temperature, whichever is higher. On the other hand, the minimum design temperature is given as minimum service temperature -5°C or minimum ambient temperature, whichever is lower. Length to diameter ratio For horizontal drums vessel diameter cannot be derived independently of its length, unlike for a vertical separator. Here, the diameter and length, and the liquid height in the drum, must be selected to give adequate vapor residence time for the liquid droplets to settle out, and also for the desired liquid hold-up time to be met. Operating pressure, economic factor, construction and others, are parameters to be considered in choosing the length (or height) to diameter ratio. The following is the general recommendation:

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Table 5.4.2 Recommended L/D ratio for horizontal drums. Design pressure

Length to Diameter ratio (L/D)

P ≤20 barg

2 to 3

20

(θliquiddropout) for case 1 and case 2, therefore, drum design is ok. Where the above solution is not the case, L/D will be increased and the steps followed again from step F. The KOD Separator Specification, therefore is: D=4.5m, L=18m (a split flow configuration), 2 inlet nozzles= 30” each, 1 outlet nozzle=34”.

Figure 5.4.11 Fabrication of the Flare KOD Separator (ASME Certified).

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Figure 5.4.12 On-site Installation of the Flare KOD Separator.

5.4.2.4 Conclusion In conclusion, careful consideration of all parameters in determining the optimal specification of a flare KOD separator for chemical or gas processing plant will lead to optimal liquid recovery, reduced flare capacity, reduced cost, and enhanced plant safety integrity and will also save the environment from possible hazard.

5.5 Economic Study of a Chemical Engineering Process Introduction During process plant engineering design, chemical engineers identify viable technical options and provide an economic comparison between them.

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Based on technical process option merits, economic cost implications (capital/operating, fixed/variable), and evaluation of the relative suitability of each process option, a final solution is reached. After determining chemical plant process and equipment specifications, the total capital investment cost can be evaluated. The project may be a new plant, plant upgrade, or a plant modification. The total investment for any chemical process consists of fixed capital investment for physical process equipment and facilities in the plant plus working capital which must be available to pay salaries, purchase raw materials, pay taxes and handle other special items (including administrative expenses) requiring a direct cash disbursement (all known as operating costs). These costs are grouped as capital investment costs and operating costs, commonly known as CAPEX and OPEX.

Figure 5.5.1 A Petrochemical Plant Under Construction at Lagos, Nigeria.

Process Equipment Cost Estimate The cost of each piece of process equipment can be estimated in many ways which include: Outcome of basic and detailed engineering and quotes from equipment suppliers/vendors; published equipment cost data; from suitable manufacturer’s bulletins; similar equipment cost, and so on. However, equipment manufacturer’s quotes are usually the most reliable and the method commonly applied during process plant construction. The likely error of the estimates based on published data is about ±30 percent while that based on vendor’s quote is about ±5 percent.

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Investment costs The total capital investment (TCI) is defined as the sum of the fixed capital investment (FCI) and the working capital (WC). The fixed capital investment is the capital required to supply the necessary plant manufacturing facilities (CAPEX), and the working capital is the capital required for the operation of the plant (OPEX).

TCI = FCI + WC Where: TCI is the total capital investment (usually measured in USD) FCI is the fixed capital investment (also usually measured in USD) WC is the Working capital or necessary capital for the initial operations of the plant. FCI is defined further as:

FCI = Direct costs + Indirect Costs The direct costs are further divided into internal (on-site) and external (off-site). There are several methods for estimating the total capital investment of a chemical process plant. The method proposed by Peters & Timmerhaus (1991) [96] – percentage of delivered equipment cost, will be applied in this case study. In this method, estimates of the costs of the specified process equipment are done, while estimates of the direct and indirect costs are determined as percentages of the equipment cost. The following Table 5.5.1 shows the evaluation of direct and indirect costs in relation to equipment cost and working capital as a percentage of total capital investment. WC = 15%TCI, hence, TCI – FCI = WC TCI – FCI = 15%TCI, where WC = 15%TCI. TCI - 15%TCI = FCI TCI (1 – 0.15) = FCI 0.85TCI = FCI TCI = FCI/0.85

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Table 5.5.1 Terms that Constitute Fixed Capital Investment. Direct Costs Internal Costs (Onsite)

 

Equipment Cost

E

Installation Cost

47% E

Piping

18% E

Instrumentation

18% E

Electrical Installation

11% E

External Costs (Offsite)

 

Buildings

18% E

Yard Improvement

10% E

Services Facilities

70% E

Land

6% E

Indirect Costs Engineering (Eng)

33% E

Construction (Const)

41% E

Contractor’s Fee

5% (Direct + Eng + Const)

Contingency

10% (Direct + Eng + Const)

TOTAL Indirect Costs Working Capital

 

Working Capital

15% TCI

Next is the evaluation of the equipment costs. Following the engineering specification of the various required process equipment, estimates of the individual equipment can be determined. As stated, this is usually based on information from the equipment manufacturers. The following Table 5.5.2 shows estimates of individual process equipment based on the specified capacity.

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Table 5.5.2 Determination of Equipment Cost. Unit Operation

Capacity

Cost

NGN

Static/Non-Proprietary Equipment

(Kg)

Eur

N

Sludge Catcher

96,500

1282000

277945292

HP Flare Knock-out Drum Separator

42,000

596100

129238057

Mercury Removal Package

76995

738150

160035349

Pig Receiver

12420

162950

35328538

Rotating/Proprietary Equipment

(MW)

$

 

Pump

3.22-4.66

50000-60000

9270168

Combustion Reactor

2.03

210000

32445588

Compressor

25.5-1.46

2200000-506000

78178417

Condenser

4.38

12500

1931285

Evaporator

2.75

460000

71071288

Heat Recovery Steam Gas Generator (HRSG)

35

1000000

154502800

Gas Turbine

46.2

2800000

432607840

Total

1,382,554,622

NB: Conversion to Nigeria naira as used here is 216.806 and 154.5028 per pounds and dollars, respectively.

TOTAL Cost (E) = NGN1, 382,554,621 Having determined the value of E, actual estimated Values of direct costs, indirect costs and working capital can now be determined. These values are shown in the following Table 5.5.3:

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Table 5.5.3 Determination of Direct and Indirect Costs and Working Capital. Direct Costs Internal Costs (On-site) Equipment Cost

E

1382554621

Installation Cost

47% E

649800672

Piping

18% E

248859832

Instrumentation

18% E

248859832

Electrical Installation

11% E

152081008

Buildings

18% E

248859832

Yard Improvement

10% E

138255462

Services Facilities

70% E

967788235

Land

6% E

82953277

External Costs (Off-site)

Total Direct Costs

4120012771

Total Costs Engineering (Eng)

33% E

456243025

Construction (Const)

41% E

566847395

Contractor’s Fee

5% (Direct + Eng + Const)

120282252

Contingency

10% (Direct + Eng + Const)

240564504

TOTAL Indirect Costs

1383937176

Working Capital Working Capital

15% TCI

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Finally, starting from the previous equations and the data extracted from the previous tables, final value of the investment cost for the Plant can be calculated.

FCI = 4120012771 +1383937176 = 5503949946 = NGN5.5 Billion TCI = FCI/0.85 = 6475235231 = NGN6.5 Billion After calculating the TCI, various methods of profitability evaluation are employed. They include return on investment (ROI) method, net present value (NPV) method, pay out time (POT) method and so on. In each of these methods, TCI is used as a function to determine profitability or economic viability of the proposed chemical process plant.

5.6 Case History Related to the Development of a New Chemical Process This narrative is an illustration and does not represent existing companies; the scenario reflects realistic steps taken to develop new chemical process at the commercial level. Development of chemical process requires interplay of multiple disciplines and capabilities. These disciplines include various specialties of chemical engineering, civil and electrical/instrumentation engineering.

5.6.1 Conceptual and Front-End Engineering Design MOG Chemicals Company’s research and development unit synthesized a route to produce 4-hydroxy-2-butanone in a chemical laboratory. Chemical process engineers allocated to work with the development group have created a process route for making the chemical in commercial quantities. The initial basis of the process is literature review and laboratory experiments, brought together by intuition of the process engineers. The group reached an agreement to proceed with the route and tested key parts of it on a pilot scale. A process engineering team from MOG’s main engineering office began to develop the process. Many process development options are created and evaluated to achieve the most profitable, reliable and safest design using simulation software such as HYSYS, PROSIM, etc. The interactive environment in the simulation software was used to perform what-if studies and sensitivity analysis. During the study, need for additional equipment or sub equipment (secondary equipment) may arise. They carried out the detailed process

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calculations, heat and material balances, individual equipment sizing, and so on. They produce a series of PFDs (Process Flow Diagrams) for the process.

5.6.2 Detailed Engineering Design and Construction Detailed process equipment design specialists in crystallization, separation, distillation, filteration, extraction, absorption and other chemical engineering specialists in kinetics, heat transfer and process control are brought in to help the process team in vital areas. Some of the specialists are company employees and others are consultants. At this stage the company has completed the front-end engineering design (FEED) of the project. The detailed engineering design involves design and production of piping and instrumentation diagrams (P&IDs) for all process and utility systems, process data sheets for equipment, preparation of material requisition, technical evaluation of sub-contractors/vendors, functional specification for equipment, control requirement specifications (Trip/alarm settings), safety requirements and plant operating procedures, preparation of all the technical documentation for construction; preparation of supply specifications for purchase orders relating to main items; preparation of purchase order specifications relating to bulk materials; preparation of the inspection data sheets; technical evaluation of quotations relating to materials and services; and issue of final Approve for Construction (AFC) deliverables. (See section 5.2.3.8 for details.) MOG is a production company, consequently, it does not have the engineering capacity (in terms of high multidisciplinary staff strength) to prepare the over 110 Piping and Instrumentation Diagrams (PFDs) and over 1800 multidisciplinary engineering deliverables needed for the new 4-hydroxy-2-butanone plant. MOG will also require an EPC (engineering, construction and commissioning) firm that can continue with the plant design and construction on contract terms. The aim of contracting out is to obtain, on the best possible commercial terms, specific works, materials, services and expertise, the company cannot provide economically for itself. The company, as a result, prepares the following: • The contract plan defining what is to be contracted out, and the preferred packages. • The type of contracting (tendered or negotiated contract). • The duration of the project. • The commercial strategy, market analysis, who should bid and why, the impact of the strategy in total cost of ownership terms, and • A risk analysis of the contracting alternatives.

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At the end, MOG selects the project execution contractor—a wellknown engineering and construction firm, D-Dino (to be referred to as the EPC contractor). D-Dino is also going to be responsible for commissioning and starting up the plant. The contract period is 26 months. MOG thereafter assigns some of their process and multidisciplinary team members to work at D-Dino to coordinate the entire scope. Most of these multidisciplinary staff of MOG are consultants. D-Dino’s process engineers, specialists, and AutoCAD drafting specialists prepare the P&IDs. They carry out the detailed engineering, including pipe sizes, valve specifications, instruments selection and so on. Other specialists in D-Dino engineering team will get involved once their process team have completed and finalized the PFDs, P&IDs, and equipment specifications. The job may take six to twelve months. The D-Dino process team will be highly loaded in the first five to six months of engineering and then will go down to two or three people. MOG awards the contract to D-Dino with a letter of authorization (LOA) that will last for a given period of time, having also a stipulated target (phase) of work to be accomplished. At the expiration of LOA, if MOG feels D-Dino should continue the job the actual contract for the full scope of the work will be awarded to D-Dino. D-Dino on receiving the LOA settles to begin to plan a detailed contract execution strategy. The EPC contractor, knowing that commissioning is part of his scope, considers also safety and quality in the planning process. The contractor begins to prepare project management and execution procedures. The entire contract scope is broken down into a manageable level called work breakdown structure (WBS). The time and cost of each component in the WBS is determined. The overall cost of doing the project (management, direct and indirect costs) are determined. Hence, D-Dino develops an integrated activity plan for the engineering, procurement, construction and commissioning phases of the project. The plan provides D-Dino with a framework to understand, approve, monitor and control the project. It also serves to identify constraints and assumptions and assess risks. Also, the material and equipment resources to be used in executing the integrated plan are defined. Once the model (Integrated Activity Plan) is created, D-Dino performs optimizations such as resource leveling and critical path analysis using planning software (notably primavera P6 and others); develops control mechanisms such as milestone and baseline schedule, s-curves, productivity monitoring systems, progress measurement sheet, and so on. The level 2 schedule prepared by D-Dino for the contract is shown in the following Figure 5.6.2.

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Overall Project Duration – 26 Months (2yrs 2 Months) Engineering – 13 Months Procurement – 22 Months Construction – 22 & Half Months Commissioning & Start up – 2 & Half Months

Figure 5.6.1 Average Timeline of Project Phases. PROJECT TIMELINE (LEVEL 1) 2010 M 1

2011 A 2

M 3

J 4

J 5

A 6

S 7

O 8

N 9

D 10

J 11

2012 F 12

M 13

A 14

M 15

J 16

J 17

A 18

S 19

O 20

N 21

D 22

J 23

F 24

M 25

A 26

M 27

J 28

J 29

A 30

S 31

O 32

N 33

ENGINEERING Site Survey Detailed Engineering PROCUREMENT Piping & Structural Steel Equipment Electrical/Instrumentation (Bulk) CONSTRUCTION Site Preparation Civil Works/Steel Structure/Buildings Mechanical (Equipment/Piping) Electrical/Instrumentation Site Preparation Commissioning

Figure 5.6.2 Project High Level Schedule.

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Every drawing is reviewed by D-Dino’s project team and by MOG’s team. If there are disagreements, the engineers and specialists from the companies must resolve them. Moreover, to avoid delay MOG had identified some long lead equipment (items) which need to be ordered well in advance. COMPANY (MOG) decides to take responsibility for the procurement of such items. Although this will subject the company to some financial risks if the equipment ultimately requires extensive modifications or will not be used at all following the outcome of detailed design. This is because the key to procurement is always having firm specifications. The detailed specification is the key to getting out a purchase order with the minimum number of change orders. MOG engineering on completing the material requisition preparation involves the EPC procurement department. Procurement covers the selection of vendors, tendering and award of purchase orders, material expediting, receipt, control, storage and issue, importation and customs clearance, spares ordering, and so on. Finally, all the PFDs and P&IDs and other engineering deliverables are completed and approved for construction. Hence, the contractor decides to sub-contract some areas of the work such as all civil works, including office buildings and so on. D-Dino begins site preparation and early construction activities—prepares site office and camp accommodation, mobilizes construction team to site. The team carries out all construction and pre-commissioning activities including prefabrication and installation of all process equipment, piping, electrical and instrumentation works. Within this period, D-Dino engineering had been providing continued support to construction, including preparation of as-built documents for the plant erection.

5.6.3 Pre-Commissioning and Commissioning Pre-commissioning activities to be performed by the team after construction encompass all the required checks, tests and proving of systems, loop checks on instruments, etc., that can be completed without the introduction of inert or production process fluids into the process. In other words, the energizing or pressuring of a system, example, testing pump motors, inspection of pressure systems, to confirm that it is safe to proceed with commissioning, is known as pre-commissioning. Finally, the precommissioning is completed, and the next step is the commissioning phase. D-Dino knowing fully well that it lacks the expertise in commissioning hires an expert from the UK to plan and coordinate the scope. The expert (commissioning manager) prepares the commissioning plan and

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with the assistance of D-Dino and MOG commissioning team, performs the commissioning activities to prove that all plant systems function as per design, before being handed over to the user. The team tests all systems with inert and then allows the charging of the system with production fluid (start-up). D-Dino prepares operation manual, as-built drawings, and so on, and consequently hands over the plant to MOG’s Operations department, which will continue with the operation of the plant.

5.6.4 Plant Operation It has been explained that chemical engineers design, construct and operate chemical plants. Chemical engineers’ role in the design and construction of plants have hence been described in the foregoing. Let us consider what they do during plant operation. A plant is usually projected to run for many years. Also, a forecast of equipment depreciation, throughput reduction and general plant performance over the years can be determined. A lot of factors can affect plant yield over time; these include quality of feedstock, equipment wear, catalyst performance or introduction of more efficient catalyst, new government industrial policy on the environment, consumer requirements, etc. Also, there may be a need for plant upgrading, retrofitting or modification. Upgrade involves improving plant’s production processes (addition of new trains)—a good way of solving inadequate production capacity. Retrofitting involves fitting new parts into an outdated or old plant usually as a result of new technology; modification involves retrofitting of plant components and process changes. Chemical plant operating engineers work mainly in the process and process control divisions. They are constantly analyzing plant processes to seek ways of optimizing production. To understand the changes taking place in a plant, engineers would collect operating condition parameters and input to the original PFD and run a simulation of the plant. Modern process simulation tools are used for this purpose. To redesign or modify aspect or a whole plant process, engineers use the baseline design parameters on the original process flow diagram (PFD) as a guide. But the current operating parameters of the plant are used as new baseline in the PFD. These current data can also be fed into simulation tool to predict impact of any plant retrofitting or modification. The entire role the plant engineer performs is to ensure optimum plant capacity, safe and efficient plant performance and increase in profitability.

6 Chemical Process Safety Engineering and Management 6.1 Introduction Chemical process safety engineering is a discipline that focuses on the elimination, prevention and mitigation of hazards such as fires, explosions, and chemical or toxic releases at process facilities. This is different from the regular workplace safety—worker health, safety and environment (HSE) issues involving working at height, ladders, working surfaces, personal protective equipment (PPE), etc. However, process safety management is all-encompassing and includes personal and equipment safety. Safety and Loss Prevention engineering is the same as safety engineering. It involves selecting and specifying the basis of the safety of a chemical process. Chemical process safety engineering and management is a blend of engineering and management activities aimed at eliminating, preventing and controlling catastrophic accidents and incidents associated with commercial or industrial operation of chemical processes. The design and production of chemical processes and products is intrinsically hazardous. CCPS’s (2008) Guidelines for Hazard Evaluation Procedures [106] defined process hazard as “an inherent physical or chemical characteristic that has the potential for causing harm to people, the environment or property”. Almost every chemical and gas plant is holding significant quantities of various chemicals, which can have serious impact on workers and local community. Chemical process incidents when they occur can be fatal. Several incidents have occurred in the past that claimed many lives. For example, an incident occurred in a plant owned by Union Carbide in Bhopal, India, on December 3, 1984. Methyl isocyanate (MIC) gas escaped to the atmosphere through a vent gas scrubber due to a runaway reaction that overwhelmed the scrubber. More than 2,500 people died and 20,000 more were injured as a result of exposure to the MIC. Human error and poor maintenance of the safety system—a vent scrubber, a pressure relief valve and a flare, was reported to be the cause of the incident. Many more incidents around the world have Uche Nnaji (ed.) Introduction to Chemical Engineering: For Chemical Engineers and Students, (253–276) © 2019 Scrivener Publishing LLC

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led to huge capital losses and loss of lives. Types of chemical process hazards include chemical reactions hazards, fire and explosion hazards, health hazards and environmental hazards. Several causes of process hazards have been discovered, including design inadequacies, deviation from design and operating procedure, inadequate training, operating equipment beyond design parameters, equipment not fit for service, fatigue, poor communication, nonfrequent operating activities, such as startup, tie-ins, or shutdown, changes in feed composition, contamination, and so on. Chemical processes go through various stages of evolution, which is commonly known as process life cycle stages. The first stage begins with the initial concept of the process (discovery chemistry) and synthesis. The selected process then goes through development, design, construction, commissioning/startup, operation, modification (as the case may be) stages and finally a decommissioning stage. Each of the stages presents unique potential hazards. Various technical and managerial approaches are being applied in ensuring sustainable chemical processes. A process safety model in practice is shown in the following Figure 6.1.

Chemical Process Safety Engineering and Management

Safer Design

Process Design for Safety (Hazard Elimination and Reduction)

Process Analysis for Safety (Hazard Identification and Control)

Incorporating Process Safety into Process Design (Inherently Safer Design)

Process Hazard Analysis/Risk Assessment (Hazard and Operability (HAZOP) Studies)

Incorporating Process Safety into Process Equipment Design (Passive Safety Features) Preventive and Protective Design Features (Active Safety Features)

Figure 6.1 Process Safety Model.

Administrative and Procedural Controls (Process Instructions and Safe Operating Procedures, Training, Admin Checks etc.) Residual Risk Management

Chemical Process Safety Engineering and Management 255 Chemical process design focuses on how to eliminate hazard in the process, while process assessment for safety focuses on how to identify, manage and control any hazards in the designed process, such as in the case of explosions, fire, or release of toxic chemicals, in order to minimize injuries and damage to facilities and the environment. Process design considers elimination or substitution of hazardous compounds, prevention of hazardous releases and protection of the chemical plants against overpressure, fire, explosions, noise and loss of content (which can occur through leakages). Risk in chemical process safety design is defined by Melhem G. and Stickles R. (2002) [107] as “the likelihood and consequences of incidents that could expose people, property, or the environment to the harmful effects of a hazard”. Risk assessment can be applied during process route evaluation in order to make a risk-based decision. However, because no inherently safer process is completely or absolutely safe, periodic risk assessments and other administrative safety measures are considered highly essential during chemical process operation. Process design for safety or inherently safer design will only move a process in the path of reduced risk (residual risk) and will not eliminate all risks.

6.2 Chemical Engineering Design for Process Safety 6.2.1 Selection of Inherently Safer Process Route Process synthesis and design starts with the discovery and selection of the most sustainable process route and a basic technology for manufacturing the process. Each alternative process route would present differing safety, efficiency, environmental impact, cost and schedule. Hence, process safety is usually one of the key considerations for the choice of a process route. Product synthesis often involves a significant number of reactions leading in sequence from original starting compounds. Engineers, working with research chemists and other R&D professionals or collecting data from chemists at this level must pay attention to reactions that occur at each step. Some substances can react so rapidly and violently that only careful control of the reaction parameters will lead to desired products and yields. Indication of what might happen if any of the process parameters is altered can be studied and documented at this stage. Several chemistry data are painstakingly generated and documented, and they include flammability, boiling point, flash point, melting point, fire point, chemical reaction data, and so on. The data from this laboratory scale are vital information that chemical engineers apply in the systematic design of a

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large-scale inherently safer process. This is what the so called inherently safer design is all about. Additional rigorous tests must be carried out at pilot scale to determine the safe operating envelope (safety limits). There has been a case where an explosion occurred in a process vessel involving a thermally unstable material. On investigation it was discovered that decomposition of the material occurred at temperature around 150oC on the plant scale whereas published data from laboratory tests were in the range 270-300oC. Investigation and proper pilot tests must be done to determine the effects of reaction kinetics, rates of heat generation and gas evolution. Many factors can affect these rates and they include holdup times or residence times, concentration of reactants, variations in feed rates, materials of construction, stirring speed/mixing rate, agitator configuration and materials of construction. Hazards that may occur during chemical reaction include: • Exothermic reactions which can lead to rise in temperature, leading to decomposition reactions or violent boiling; • Gas evolution (neutralization reactions, particularly acidbased reactions); • Thermal instability of reactants, intermediates, reactant mixtures and products, by-products (including potential contaminants). Chemical reactions that could cause fire, explosions, toxic gas releases, runaway reactions or potential reactivity hazards are identified at this stage and measures to prevent impact conceived. For example, design of emergency vent system that provides protection against runaway reaction involving reaction rates and gas flows that may exceed design conditions can be considered. Runaway reactions can occur if the rate of heat generation from a reacting mass exceeds the rate at which heat is being removed, thereby causing an uncontrolled increase in temperature. Where adequate overpressure relief is not in place, if the heat of reaction surpasses the cooling capacity, the reaction rate can accelerate (runaway) and may cause a gas evolution rate that overwhelms the vent header system. Also, at this stage of process synthesis, thermodynamic and physical properties of materials must be thoroughly studied.

6.2.2 Process Design Rudimentary errors in the process design of operating chemical plants often lead to intolerable risks of major accidents or production losses.

Chemical Process Safety Engineering and Management 257 Early elimination of risks often prevents costly modifications being made later in the project. Essentially, process safety is a key constraint to consider during process design. The design concept entails finding ways to eliminate or substitute hazardous compounds, prevent releases, develop containment, safely dispose chemicals, introduce ventilation and prepare reliable emergency procedures. Early engagement of experienced process safety engineers who have good knowledge of process chemistry, for chemical process projects, is consequently, very consequential. (Refer to section 4.3.8 for detailed job roles of process safety engineers.)

Figure 6.2 Process engineers design and operate chemical plants. Credit: Schlumberger.

During process design, engineers apply best intuitive judgment and past experiences in specifying a general configuration of all major equipment or units that will be inherently safer to operate. The engineers begin by asking several critical process-related questions. The Gas and Chemical Process Safety Unit—a part of the technology division of the Health and Safety Executive in the United Kingdom—listed some of the process-related questions engineers must ask while selecting and specifying basis of safety. Such questions include but are not limited to: • Is it possible to eliminate hazardous raw materials, process intermediates or by-products by using another chemistry? • Is it possible to substitute less hazardous raw materials? • Have all in-process inventories of hazardous compounds in storage tank been minimized? • Has processing equipment location been optimized, to reduce the length of hazardous material piping?

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Introduction to Chemical Engineering • Has all chemical processing equipment handling hazardous compounds been designed to minimize inventory? • Is there a way hazardous compounds can be generated in situ from less hazardous reactants, instead of having them stored in the plant? • Can the use of a catalyst make reaction conditions less severe? • Can the process equipment be designed to totally contain the maximum pressure produced? • Can semi-batch chemical processes be redesigned to reduce accumulation of reactants? • Is there a way process equipment can be designed such that it will be difficult or impossible to create hazardous situation as a result of operating error?

In doing so, they imagine failure scenarios by asking questions such as: • Can anything go wrong? • If anything goes wrong, what impact will it have? • Are the potential failure scenarios cause to worry about and what is the probability of them occurring? • What is the risk of tolerating the potential failure scenarios and their impact? • And so on. This way, process designers consider risk factors while specifying concept and sequence of equipment, materials and conditions that drive the concept. They design both the intrinsic (inherent or built-in) safety systems, passive safety system and active safety systems. Once an inherently safer process has been achieved, engineers will develop process instructions and prepare safe operating procedures. Intrinsic/Inherent/Built-in Safety System The inherent safety concept eliminates or greatly reduces hazard by changing the process to use process materials and conditions that are not hazardous or much less hazardous. One instance cited by Hendershot (2011) [108] is “substituting water for a flammable, and perhaps also toxic, solvent as a carrier for a paint or coating (e.g., using water-based latex paints instead of oil-based paints)”. Another example includes replacing batch reaction processes with semi-batch or continuous processes—this will reduce the quantity of reactants that will be present in the process; input

Chemical Process Safety Engineering and Management 259 rate can be controlled, and the process can easily be stopped in the event of hazard. Also, the use of catalysts which will lead to use of less reactive reactants and wide safe operating envelopes. Safe operating envelopes are safety limits of the operating conditions, the wider the safer the process. Another inherent safety design concept is the selection of processes which are less sensitive to variations in operating conditions (especially temperature and pressure). Inherently safer design is a design that seeks to eliminate inherent hazards and reduce the need for expensive safety systems and procedures. In some cases, codes and standards (such as API codes and standards) exist that either mandate or suggest design solutions to known high risks. Inherently safer design philosophy or safety consideration applies at all stages of process and engineering design and up to detailed engineering design, construction and commissioning (including start up). It also applies to plant modification or expansion. However, the best opportunities for incorporating safety into design are in the process synthesis (laboratory research) and design phase. Use of simulation tests can reveal so much about reaction hazards inherent in a process.

6.2.3 Incorporating Process Safety into Process Equipment Design Process conditions of a process equipment impacts all activities that enhance safe operation of the unit. Consequently, careful definition of equipment operating conditions, maximum and minimum (safe operating envelopes), as well as normal, is essential. Process safety concept is factored into the design of process equipment to achieve inherently safer process equipment. Engineering codes and standards has been developed to provide guidance for the design. The chemical engineering design of safe process equipment begins with the definition of the process requirements, which serves as input data for the design. This is followed by mechanical design, material selection, and then fabrication methodology, coupled with quality plans and procedure. These steps are carried out by the concept of safety. This concept is also applied in the maintenance and inspection of the equipment during plant operation. Fabrication techniques and inspections can affect inherent safety of process equipment. For example, improper welding, poor testing or poor welding inspections, improper heat treatment, poor fittings and assembly, dimensions outside permissible tolerances and so on, can reduce the integrity and reliability of process equipment.

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Mechanical integrity in a chemical plant entails using generally accepted and recognized good engineering practices to confidently contain all the hazardous chemicals within the equipment and piping systems (Sanders, 1999) [109]. Mechanical integrity can be guaranteed by: • Carefully designing to meet or exceed standards; • Using proper materials for fabrication; • Using proper construction and installation technique and testing to confirm equipment stability; • Ensuring that the process equipment remains fit for service (through periodic inspection, testing, documentation and restoration programs). Process Safety Factor and Process Over-Design Safety factors are considered during process design of equipment to account for expected degradation and aberrations, for example, corrosion or surges deviations, contamination in the process streams and so on. The safety factor also accounts for variations, uncertainties and potentially erroneous decisions concerning, for instance, operating conditions, operating rates, conditions of the process materials and process feeds. Hence, safety factors are applied to critical operating conditions to make sure that catastrophic failure of systems or units does not take place for any unforeseen reason. There are engineering codes and standards for safety factors such as contained in ASME code. Safety factors should not be mistaken with over-designing a process. Over-design usually involves planning for future conditions and equipment. In a situation where engineers have plans to expand the capacity of a process unit, they may decide to specify a pump with extra capacity to handle the future increase in feed rate or height of a tower. Consider instead of installing a 1-HP water pumping machine which can adequately pump the water required in your bungalow building, you decided to install 2-HP in an anticipation that you will build a two-story house in the future. This is what over-design implies. Passive Safety System Passive safety systems are those risk factors that are factored into the design of process units. For example, sometimes a factor of, say 10% is added to an equipment derived operating pressure due to safety considerations (see section 5.4.2.2 where safety consideration was made in deriving the design parameters of a process knock-out drum separator). The same safety consideration can be made in deriving the thickness of the material for fabricating the equipment. A passive approach, however, may not eliminate

Chemical Process Safety Engineering and Management 261 hazards completely. The assumed safety consideration may be underestimated or hazards may occur through other sources such as leaking gaskets or corroded metals.

6.2.4 Preventive and Protective Design Features Preventive features help to prevent the mistakes of, for instance, adding wrong reactants or adding right reactants too early or too late, too slowly or quickly, too little or too much and/or adding the reactants in the wrong order. It ensures the process is operated within safety limits, hence, adequate measures are taken to inspect functional reliability of process control systems. Critical sequences of failures that can cause a hazard are considered in the systematic design of automatic control systems. Automatic safety control systems are designed to high standards because loss of control can lead to major disaster—injury to people, plant and the environment. A preventive design feature therefore reduces the chances of a hazardous situation occurring, while protective features reduce the impact of a hazardous situation. A gas explosion, for example, can be prevented by keeping the concentration of the combustibles below the lower flammability/explosible limit (LFL/LEL). In a situation where liquid combustibles are anticipated, a gas explosion can be prevented by controlling the process temperature below flashpoint, in as much as mists formation does not occur. In the case of combustible gases and liquids at temperatures above their flashpoint, ventilation can be applied to control gas concentration, typically below 25% of the LFL. Apart from introducing explosion preventive concept to the design, containment is another concept that goes into design for protecting workers from impact of explosion. Containment means to construct an equipment or a vessel that can withstand the maximum impact (explosion pressure) of gas explosion. Other protective or loss prevention features include emergency pressure relief or venting system and flares, reaction inhibition system, corrosion inhibition system, static electricity control, purging and ventilation system, crash cooling drop-out, fire suppression system, positive pressure buildings and quenching system, etc. The emergency relief system relieves excess fluid from a reactor or pressure vessel due to overpressure, runaway reaction or uncontrolled exothermic reaction. The discharge from the relief system is disposed through knock-out drums, scrubbers, quench tanks and flare racks. Section 5.4 explains the detailed steps in sizing a knock-out drum which is used for separation of liquids (discharge) from emergency relief system, carried with gas streams flowing to the flares. A pressure relief device can be a rupture disk or a spring-operated pressure

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relief valve. To size a pressure relief valve, the process engineer envisages several factors, including considering the possible temperature and pressure increase expected in the incident of internal process upset, as well as the discharge location. Also, other factors considered include the pressure drops across the relief device and the friction losses in the process discharge lines. All protective features normally rely on an automatic control system to operate, with the exception of containment and venting. Process design engineers must ensure that all unavoidable potential hazards have been envisaged and adequate safety systems are in place to reduce the overall risk to a tolerable level.

Figure 6.3 Safety, Alarm and Shutdown Protection for the Plant. Credit: Stephanie Neil, https://www.automationworld.com/article/industries/chemical/safety-alarm-andshutdown-protection-plant, 2019.

Chemical Process Safety Engineering and Management 263 Active Safety System Active safety systems are engineering controls (preventive and protective design features) that are designed to detect hazardous conditions and either alert personnel or take action to prevent occurrence. They include, for example, automatic instruments that shuts valve when fluid in a tank gets to its maximum capacity. An automatic level indicator/controller instrument generates a signal when liquid in a tank rises beyond safe limits; a transmitter sends the signal to an inlet control valve so it can close and then to the outlet valve to open, to a discharge pump to turn on and the charge pump to turn off. Others are fire and gas detectors that send a signal upon sensing smoke or fire; toxic material detectors, and so on. Their contribution to loss prevention in a process plant is high. Field instruments, controllers and various safety devices all serve to keep the hazard contained, but none is 100% reliable. Each however, still has a probability of failure. Hence, the limits of this type of device, its power source and failure mode must be properly taken into consideration. Protective features thus are the last line of defense designed to protect against the worst-case scenario. Automated control systems and safety devices are represented in a process flow scheme symbolically as shown in Figure 6.4.

TC

TI

TR

Temperature Indicator

Temperature Recorder

FR

FI

FT

TT

Flow Recorder

Flow Indicator

Flow Transmitter

Temperature Transmitter

Temperature Controller

FC Flow Controller

(a)

Control Valve symbol (both pneumatic and electric actuators)

Failure mode - the direction of the arrow shows the position of the valve on failure of the power supply

(b)

Figure 6.4 Active Safety Instrument Symbols.

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FRC LC

TC

Stream

Temperature Control

Level Control

Recorder Controller

Trop

PC

PC

PC

Process vapour

Pressure Controllers

Coolent

FC FC

FC

TC

LC

Feeds

Coolent

Process Safety Instruments around a reactor

Figure 6.5 Active Safety Instruments and their Connection to Process Equipment.

6.2.5 Safety Administrative or Procedural Control (Active Solutions) Safety administrative or procedural control is a safety management process that requires human action or intervention. The actions may involve responding to an alarm, reacting to a leak, a strange noise, an instrument reading, a test sampling result, etc. It requires following a standard operating procedure in responding to these indications of a problem. Hence, it may involve steps such as manually closing a valve after hearing an alarm sound, in order to prevent a vessel from overfilling, or completing punch lists or carrying out preventive maintenance to reduce the possibility of equipment failure. Procedural solutions are generally the least reliable safety control measures because of the human factor involved. The human factors include unsuitable split of tasks between machine and worker and poor safety culture.

6.3 Process Hazard Analysis Techniques Process hazard analysis or evaluation is a set of structured and systematic assessments of the potential hazards associated with a chemical process. In most countries, hazardous installations or chemical process facilities are

Chemical Process Safety Engineering and Management 265 mandated to demonstrate that they have reduced the risk to people and the environment as low as reasonably practicable (ALARP). Process Hazards come from two sources: a. Hazards that are characteristic of the materials and chemistry used; and b. Hazards that are characteristics of the process variables and process plant. The most common process hazard analysis (PHA) method is the hazard and operability (HAZOP) study. However, there are other process hazard analysis techniques such as fault tree analysis (FTA), event tree analysis, what-if/checklist analysis, human reliability analysis, layer of protection analysis, bow-tie analysis, failure mode and effects analysis (FMEA), etc.

6.3.1 Hazard and Operability Study (HAZOP) HAZOP in chemical engineering terms can be said to be a structured and systematic examination or investigation of a planned or existing chemical process or operation in order to identify and evaluate issues that may signify risk to personnel, process equipment, the environment or prevent efficient process operation. The study focuses on how the process will cope with abnormal conditions. HAZOP can be applied at various stages of chemical process plant facility development. However, the most critical or ideal stage is during process design. This is because it is economical to effect any significant change in the design at this stage without incurring huge additional expenses. The concept brings a multidisciplinary team to a meeting table to brainstorm and review the process with the major aim of identifying hazards or operability problems that may occur due to process parameter deviations from the design intent. The creative process design is carried out by chemical engineers. The study provides opportunity for team members to think creatively and examine ways operating deviations that may lead to hazards might arise. A HAZOP study is conducted systematically, comprising a review of each process unit operation, examining for possible causes of far-reaching process abnormalities and their consequences. A HAZOP is carried out in a structured but systematic manner, using guide words in order to minimize the chance of missing something. Uses of HAZOP in Process Plant Development HAZOP helps to identify all possible process deviations from the design intent and all the hazards that may be associated with these deviations to

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improve the safety and reliability of a chemical process. Other uses of the activity include: • Serving as an instruction and study material training of plant personnel. • Contributing to plant safety study policy. • Serving as the input or basis for the preparation of the final version of the standard process operating procedure and emergency plan. • Generating documentation (HAZOP Drawings and a record of completed actions) that serves as evidence while dealing with insurance engineers. It helps insurance companies to quantify the level of risk the plant may pose. • Helping in the creation of fault trees. • Helping to detect any possible malfunction that may lead to plant shutdown and loss of productivity. Documents Required for HAZOP Study Major documents or information required for HAZOP study are: • Process chemistry • Process description/narrative with heat and material balances and associated flow schemes • Piping and instrumentation diagram (P&ID) • Process data sheets • Process calculations • Instrument data sheets • Layout requirements (Piping schemes) • Hazardous area classification (Plant plot plan) • Interlock schedules (which helps operators maintain sequence of operation) • Process data utilities (electricity, cooling water, inert gas, steam, etc.) Note that the above requirement may slightly vary, depending on the type of process being studied. Piping and Instrumentation Diagram (P&ID) The last stage of every process design is the development of detailed P&ID. This is the critical document for HAZOP study. The document, as explained

Chemical Process Safety Engineering and Management 267 Table 6.1 Features of HAZOP Study. Features

Description of Features

Hazardous conditions

Energy source exposed, Process operating limit reached, Release of material (loss of containment), Etc.

Subsystems of Interest

Static equipment, pressure vessels, process lines, valves etc.

Effects within Plant

Changes in plant inventory, Change in physio-chemical conditions, Etc.

Modes of Operation

Plant start-up mode, Process normal operation, Plant shutdown mode, Construction mode, Maintenance and inspection mode.

Trigger Events

Human error, Process equipment or instrumentation failure, Emergency external events such as earthquake and other natural disasters, Supply failure, others

Corrective Actions

Change of process operating envelope, Change of process design, Change of system integrity and reliability, Change of process control system, Upgrading of material containment, Addition or removal of materials, Improve Isolation, Etc.

in Chapter 5, is developed from process flow diagram (PFD). It shows the functional relationship of piping, instrumentation and system equipment and sub equipment, including the physical sequence of branches, reducers, process equipment, valves, process instrumentation and control interlocks. The P&ID development will include the following consideration: • Safety interlock system – designed to stop operation or affected part of the process during emergencies.

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Introduction to Chemical Engineering • Alarm system – designed to alert or call the attention of operators when there is an unusual situation. • Basic process control system (closed loop control) – designed to maintain process within an acceptable operating area. • Relief system – designed to evacuate or discharge material safely in the event of internal process upset or overpressure.

A fully mechanized P&ID contains the following features: • Process equipment with names and numbers • General arrangement of the process primary and secondary equipment • Process piping, sizes and identification • Flow directions • Process valves and their identifications • Field instruments and designations • Permanent start-up and flush lines • Interconnection references • Interfaces for class changes • Vendor and contractor interfaces • Seismic category • Identification of components and subsystems delivered by vendors • Quality level • Control inputs and outputs, interlocks • Master control station • Annunciation inputs • Miscellaneous including vents, drains, sampling lines, reducers, and special fittings HAZOP Methodology The following are the general steps undertaken to implement full HAZOP study of a chemical process design:

Define Objective and Scope

Select the team

Prepare for the study

Figure 6.6 Steps to implement full HAZOP.

Carry out the examination

Follow up

Record Results

Chemical Process Safety Engineering and Management 269 Define Objective and Scope The study begins with the definition of the scope. The project manager or the project engineer sets the overall objective and scope of the study. The objectives are usually: • to review the design intent to obtain questions leading to hazard detection and recommend mitigation actions; • to improve the overall safety of the chemical process; • and sometimes to evaluate and decide whether to purchase a piece of process equipment. Composition of HAZOP Study Team A HAZOP study team for a chemical process usually consists of process engineers, research and development chemist, project engineer, construction engineer, operations engineer, electrical engineer, automation and instrumentation engineer and a pharmacist (where applicable). Four to five technical team members is ideal. However, if the HAZOP scope requires wider participation, the study can be split into discrete parts. Study Preparation The study preparation begins with writing the study program. Then, setting the study format and procedure; obtaining the study materials and converting the data into suitable form; and arranging necessary meetings leading to the study. This analysis is commonly led by a simple series of questions that define how and where things can go wrong through opinions of very experienced people. The HAZOP Study (examination session) Upon completion of the process design, leading to firmed-up P&IDs, chemical engineers are invited, along with plant and other experts, to present the design for hazard analysis. Through process line by process line study, team members identify areas that require attention in order to minimize the level of risk in the process to a tolerable level. The study sessions commonly follow these steps: • Relevant P&IDs are displayed on the wall and the process design engineer begins by describing the process and outlining the purpose and specifications of the section of the P&ID (process unit) under study. Questions regarding the scope and intent of the design are answered.

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Introduction to Chemical Engineering • The study leader then applies the guide words, as listed in Table 6.2, and the discussion can start. Each of the guide words prompts team members, with questions such as “What can make the flow to stop?”, “What happens if the flow is high?” and so on. By so doing, the team can systematically detect the ways in which the process unit under study may fail or be improperly operated, which would lead to undesirable operating conditions. Any possible deviation from normal operating condition is analyzed, the direct causes and consequences are systematically traced. Then, the adequacy of the specified safeguards would be analyzed. Industry standard operating procedures are also discussed. • Any process change agreed will be noted and marked on the master P&IDs on the wall. These P&IDs would later be known as HAZOP master P&IDs. • Minutes of meeting would be taken to note all vital discussion points and actions (where applicable). To avoid over dwelling on a specific problem, the issue can be noted so that the solution can be further evaluated outside the meeting.

Follow up HAZOP actions are tracked for implementation in the action register. Periodic meetings are organized to review progress status of the actions. The project manager or project engineer usually drives this. Recommended actions may involve a change in the process, example, process materials. Other actions may include changing the physical design of the process, changing the process conditions or changing the operating procedure. Some of the actions may remove the identified hazards completely or reduce them to a tolerable level. Also, where the prospect of complete removal of the hazard is not feasible, the team may recommend adequate safeguards to protect people and plant if the risk occurs. The HAZOP drawings and the completed action register are retained as the plant’s technical documents. Also, any major design changes suggested during the study would be considered for further investigation. This will follow management of change procedure—a standard project management procedure for implementing technical changes. Record Results Any significant problems identified are recorded in the HAZOP record sheet (see Table 6.3). The results are recorded using guide words in Table 6.2. The recommendation will be included in the final version of the plant’s standard operating procedures.

High temperature

High pressure

High flow

High level

Fast mixing

Too long/too late

Too fast

Too low

Too long

Temperature

Pressure

Flow

Level

Agitation

Time

Start-up/Shut-down

Vibrations

Draining or Venting

Maintenance

More

Parameter/ Guide Word

Table 6.2 HAZOP Guide Words.

Too short

Too high

Too slow

Too short/too soon

Slow mixing

Low level

Low flow

Low pressure

Low temperature

Less

backwards

Reverse flow

Reverse

Deviating pressure

Actions missed

Missing actions

Different level

Deviating concentration

Delta-p

As well as

None

None

None

Sequence step skipped

No mixing

No level

No flow

vacuum

None

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Failure of water source leading to backward flow

Less cooling, possible runaway reaction

Reverse

1.

Reverse cooling flow

Consequence

Possible Causes

Guide Words

S/N

Deviation

Team Members: Facilitator: Minutes by: Available Safety Provision (Existing Safeguards)

HAZOP RECORD SHEET/REPORT FORM

Project: System: Drawing:

Table 6.3 HAZOP Record Format.

Recommendations (Action Required)

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6.3.2 Process Safety Design Verification Process safety design verification is a review usually conducted by third parties on a process development project. It helps to increase confidence in safe design and suggests specific actions to reduce the risks of major occurrences. The risk-based assessment can be done during the design development stage of a project, front-end engineering design stage, detailed design stage, plant modification or operating stage. Design verification activity gives the confirmation that the detailed documentation and calculations supporting the requirements of the engineering process safety design standard have been correctly performed.

Figure 6.7 Safety Instrumented System Review (taken by the author during a design review meeting at Celle, Germany).

The assessment begins with a review of the basic process safety data (P&IDs, data sheets, reaction data, design philosophies, and so on), often known as Process Safety Information (PSI). The data are confirmed adequate, consistent, produced by appropriate methods and checked properly at this stage. Also, the risk assessment carried out for the process design (example, a HAZOP) is analyzed for adequacy and all actions are confirmed closed out. In addition to risk assessment, process safety design verification includes analyzing the safeguards or layers of protection designed to protect against identified hazards (usually including relief and blowdown

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design and safety instrumented systems). This is often known as layers of protection analysis (LOPA).

6.4 Process Safety Management The Occupational Safety and Health Administration (OSHA) [110] defined 14 elements of a Process Safety Management program. The elements are interdependent and are designed to work together to foster practices to enhance life, property, environmental safety and business sustainability. One element can contribute to other elements. Either an element supplies the information needed by another element to allow for the other element’s completion, or an element requires information from other elements to be completed. The elements are listed and described as follows: 1. Process Safety Information Technical data and all relevant information about hazards of substances used in the job must be known to employees. The information includes physical properties and reactivity data, corrosivity data, thermal data, chemical stability data, permissible exposure limits associated with the material, toxicity information, safety limits for operating conditions such as temperature, pressure, flow rates or raw materials composition, etc. 2. Process Hazard Analysis Process safety analysis are performed to identify, evaluate, and control hazards involved in a process and hence, determine possible impact of identified hazards on employees and the environment. This is required to be done periodically to ensure employee safety and plant reliability. 3. Operating Procedures A written instruction on the safe process of operating the plant. The procedures can be reviewed yearly. Various operating procedures are usually prepared for use in a given plant, including start-up, normal operations, shutdown and maintenance procedure, and so on. 4. Training Workers involved in plant operations are required to be adequately provided with safety training periodically and on a continuous basis. Several safety training areas including

Chemical Process Safety Engineering and Management 275 electrical safety, working at heights, working in confined space, hazardous material storage, hydro and gas testing, etc., are essential. 5. Contractors Contractors and sub-contractors are to be adequately inducted by operators prior working in a process plant. It is the responsibility of operators to ensure that contractors conform to the acceptable safety standards. Operators are also expected to organize regular safety training program for their contractors. 6. Mechanical Integrity Periodic inspections are required to be carried out on process equipment, including pressure vessels, ventilation systems, piping systems, etc. Equipment safeguards must be adequately inspected. Written procedures must be available for safe periodic inspection of critical equipment. The procedure contains inspection periods, required testing, quality assurance, maintenance and repair methodology and so on. 7. Hot Work A work permit must be obtained before embarking on hot works such as welding, cutting and grinding. There should be guidelines for performing hot works in a hazardous area within a chemical plant. All safeguards must be in place to prevent fire or explosion. 8. Incident Investigation Operators are required to thoroughly investigate any incident or near miss with potential for serious safety or environmental consequence. Plant operators usually have guidelines or procedures for investigating incidents. 9. Compliance Audits Periodic audits by a third party are also important for safe operation of plants. Auditors should be experts who are knowledgeable in the type of operation they are auditing. 10. Trade Secrets Chemical process companies are required to divulge their technical details, including technologies, technical procedures and/or what is known as trade secrets to their employees. This will help guide and protect employees who are implementing the technologies from danger or exposure. Plant management can, however, choose to enter into a confidentiality agreement with employees.

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Introduction to Chemical Engineering 11. Management of Change Companies are expected to have an established written method for managing change arising during plant construction or operation. This is more so because changes to design or those done in a process plant can present new hazards that must be reviewed and mitigated. Considerations can include the technical basis for the change; impacts to safety, health and the environment; required time to complete the change; and change approval from top management. 12. Employee Participation Employees are required to be involved in every process safety management program at their worksites. Companies are required to develop a written plan on how employees can be involved in safety programs. Several of such safety programs that involve employee participation include periodic safety meetings, safety drills, job hazard analysis, observation cards, and so on. 13. Pre-Start-up Safety Review Employers are expected to carry out pre-start-up safety review for both new and brownfield (modified) plants in order to minimize the potential for incidents. The review can include operating procedures, completed hazard analysis safety information, trainings done, workers awareness of changes, etc. 14. Emergency Planning and Response Companies are required to develop and publish emergency planning and response procedure workers at worksites can track. The plans can include emergency contact phone numbers, muster points, evacuation routes, method of communicating emergency, emergency response personnel, etc.

7 Sustainability in Chemical Engineering Design 7.1 Introduction Sustainability can be defined as a dynamic equilibrium in the process of interaction between a population and the carrying capacity of its environment such that the population develops to express its full potential without producing irreversible, adverse effects on the carrying capacity of the environment upon which it depends (Ben-Eli, 2015) [116]. This definition highlights economic, social and the environmental objectives of sustainability development. It has been discovered that a delicate balance of solar energy distribution between the atmosphere and the planet sustains life on Earth. This balance is facilitated by the so-called “greenhouse gases” (GHGs) – carbon dioxide (CO2), methane (CH4), nitrous oxide (NOx) and so on, which, although existing as traces in the atmosphere (current level of CO2 is 380 ppm), are believed to be responsible for global warming (Hatziavramidis, 2011) [117]. Annual global CO2 emissions as a result of fossil fuel consumption and flaring were estimated at 6320 million metric tons carbon equivalent. Increased levels of the GHGs, particularly, CO2 (from industrial emissions) leads to climate change, which alters an inherent ecosystem. An ecological system is a community of living things interacting with each other, and also with their non-living environments. Disruption of an ecosystem can lead to extreme weather conditions (rising temperatures), rising of the sea levels (as glaciers melt), erosion of soil (as the trees are used up), increasing shortage of fresh water (alteration of soil and water quality), adverse health effects (arising from pollution), alteration of biodiversity, and so on. Resources are finite and under pressure for exploitation. Currently, more than a billion people do not have adequate access to fresh (clean) water. Sustainability in chemical engineering terms involves designing economically viable processes and products that utilize as little of non-renewable

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Figure 7.1 The Environment.

materials as possible, while at the same time minimizing emissions of substances that affect the balance of the ecosystem. Sustainability in chemical engineering design is a design activity done such that the designed process, product or outcome would be profitable without harm to life, the environment and values of the society. It also involves searching for a whole new solution, or new inherently safer process in a situation where the existing technology cannot be said to be sustainable. Existing technology can become sustainable by making it more energy and resource efficient (example, through plant retrofits). The three key sustainability objectives—economy, social and the environment—are variable design constraints that push against each other, the most appropriate level of which needs to be determined. While economic and social values require maximization, impact to the environment would need to be minimized in every case. Looking at these three aspects of sustainability, one would notice that they are not new constraints when it comes to a typical chemical engineering design consideration. However, nowadays, sustainability is being viewed as an additional constraint that needs to be integrated into design because of the rising global impact of industrial emissions to the environment and the increasing consumption of non-renewable natural resources. Any venture or design that is not economically viable cannot be said to be sustainable. Equally, any profitable enterprise that impacts the environment and the consumer is not sustainable. For example, there is an increasing pressure on the need to completely discontinue the use of nuclear reactors as a means of energy generation due to their potential danger to people and their environment. Similarly, society is seeking alternatives to energy generation from petroleum and coal due to its impact on air quality,

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Economic (Profit) Eco-efficiency

Equity Social (People)

Sustainability Livability

Environmental (Planet)

Figure 7.2 Interaction between Three Key Sustainability Aspects.

health and its contribution to fossil fuel depletion. Also, hydrogen power generation system can affect the ecosystem. These technologies are profitable and are presently sustaining humanity’s needs; consequently, from the economic point of view they are sustainable human endeavors. What this entails is that hence, there is a need to push research further to find out how to improve these technologies by lowering their impact to the environment, social and natural resources and/or inventing alternative technologies that will satisfy the three main constraints at any point in time. Several sustainability literatures reviewed indicate that emphasis on this subject includes searching for the alternative to the use of non-renewable materials; how to reduce the use of finite materials (including efficient use/ consumption and reuse of energy, products and services), how to reduce greenhouse gas (GHG) emissions; how to improve manufacturing processes, and how to reduce the impact of chemical process and systems on safety of life.

7.2 Sustainability Model Furthermore, attempt is made in Figure 7.3 to model all activities related to the global sustainability development effort and show the role chemical engineers play in this human endeavor. The model generally seeks to reduce the output of greenhouse gas (GHG) emissions and preserve the planet’s ecosystem. Carbon Footprint (CF) is a method used to quantify the amount of GHG emissions caused by a corporate organization, or that coming from the life cycle of an activity or a product/service, in order to estimate its contribution to climate change.

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Sustainability Model

Sustainable/ Renewable or Alternative Raw Materials

- Alternative to nonrenewable Raw Materials; - Sustainable Materials; - Scientific Researches; - Sustainable synthetic routes

Sustainable Process Synthesis and Design

- Green Chemistry - Chemical Process Plant Design; - Process Plant and Utility Retrofit; - Process Optimization; - Process Intensification; - Process Integration Design; - Process Systems Design; - Chemical Process Life Cycle Analysis; - Designing for Minimization of Feedstock Needs; - Designing for Reuse and Recycling; - Designing for Minimization of Renewable Materials; - Fuel Cell Process Design - Value Analysis

Sustainable Utility and Environmental Design

- Utility Design by Civil, Mechanical, Electrical Engineers etc.; - Utility Design by Architects, Urban and Regional Planners; - Horticulturalists; - Design of a Solar Hybrid Car; - Sustainable goods

Sustainable Manufacturing Process

- Industrial Engineering Research; - Life Cycle Assessment (LCA); - Quality Process Improvement; - Engineering Management; - Systems Engineering; - Health, Safety and Environment (HSE); - Profitable Manufacturing Process; - Ergonomics - Value Analysis - Mathematical Modeling - Lean and Six Sigma

Sustainable Consumption/ Behaviour

- Environmental Management; - Life Cycle Management; - Organizational Policies/Social Responsibilities; - Government Regulatory Roles (Environmental Impact Assessment); - Conservation and Management of Natural Resources; - Adequate Management of Chemicals; - Arts & Culture; - Reuse and Recycling; - Social; - Sustainable services/behavior - United Nations Policies

Figure 7.3 Sustainability Model.

Chemical engineers can be involved in all the sustainability development areas as shown in the model. But sustainable Process Synthesis and Design is rather the core domain of chemical engineers. This is where sustainability is being integrated into chemical engineering design. As a result, the potential for reducing future environmental, social and cost impacts has been proven to be greater in the process design stage than in any other level in the product and service development cycle. For mature products or established processes, a similar opportunity can be recaptured by conducting a life cycle assessment (LCA) of the products development process (Vargas C. et al., 2015) [118]. (LCAs are discussed in detail in Section 7.2.2.)

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According to Thompson, Hallstedt and Isaksson (2012) [119], sustainability requirements in chemical engineering design are commonly perceived as extra costs, due to, for example, generating additional design constraints that must be met or increasing testing and assessment costs. Similarly, carbon capture, a method for reducing carbon emissions, can reduce operational efficiency, thereby impacting the overall process economics. In addition, the paradigm of product development toward increasing value (and profit) by reducing costs and increasing benefits is unlikely to change. Therefore, integrating sustainability in design will require creative, innovative, and heuristics reasoning by the engineer that seeks to achieve optimal design solution. In this case, the sustainability factor contributes substantially in modeling a profitable, acceptable and environmentally friendly products. Many chemical engineers are involved in the search for sustainable raw materials and design and development of sustainable processes. A chemical engineering professor, Frances H. Arnold, recently received the 2018 Nobel Prize in Chemistry for creating catalysts that permit more environmentally friendly manufacturing of chemical substances, including pharmaceuticals and renewables. Key stakeholders have come to view sustainable design as offering significant opportunities to shift global consumption and production patterns to a more sustainable model, given their potential in theory and practice (Clark et al., 2009) [120]. Sustainable chemical engineering design involves thorough innovation approaches that target new product/ process development and product-service systems that would challenge current consumption and production patterns by unequivocally rethinking products and services based on consumer needs. The chemical process design engineer must ensure that resource consumption and waste generation are minimized. He must think of ways of recovering, valorizing and reusing waste within a process or between processes. Given the importance of sustainability, all the chemical engineering design constraints seems to have now been encapsulated by sustainability constraint, although some engineers still view sustainability as an additional design constraint.

Classic ChE Design Consideration

• • • •

Cost Safety User Needs Environment

Modern ChE Design Consideration

• Sustainability

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Quest for sustainability or alternative use of fossil fuel has led to an increasing attention to biotechnology. Chemical engineers, as explained in Chapter 3, are driving the sustainable biotechnology. Biorefinery is a process technology developed by chemical engineers. It utilizes chemical engineering principles, which can be compared to that of fossil fuel refinery. Biorefinery is a complex plant that processes biomass feedstocks (from plants and algal materials) to efficiently produce sustainable energy, chemical and material products through a combination of chemical, physical, biochemical and thermochemical processes. This process ensures benefits to society and the environment. Biomass can either be used directly through combustion to produce energy, or indirectly after converting it to various forms of biofuel. Particular skill is required by the engineer to guide design decisions that will reduce or eliminate adverse impact upon society, the environment and the economy. Method and tools to integrate sustainability in the design are introduced in the following sections.

7.2.1 Sustainable Raw Materials Sustainable raw materials are those raw materials that lead to very high product conversion rate with minimal or no undesired by-products or wastes. Also, they are environmentally friendly raw materials. Chemical engineers are involved in finding alternative synthetic process route that increases the efficiency of materials conversion to desired products. Efficiency of raw materials utilization in a given chemical process can be evaluated by calculating their atom and mass economy. The route with higher atom and mass economy efficiency will be selected. This is what so-called green chemistry entails. Let us examine the synthetic routes for the production of maleic anhydride as an example. Maleic anhydride is an organic compound produced industrially for applications in coatings and polymers. The organic compound formula for maleic anhydride is C2H2(CO)2O. The possible synthetic routes are:

2C6H6 + 9O2

2C4H2O3 + 4H2O + 4CO2

Benzene air C4H10 + 3.5O2 n-butane air

(7.1)

maleic anhydride C4H2O3 + H2O maleic anhydride

(7.2)

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Benzene route has six carbon atoms in benzene and four carbon atoms in the product. The atom efficiency for the carbon atom, hence, is 4/6 X 100 = 66.7%. Similarly, n-butane route has four carbon atoms in nbutane and four carbon atoms in the product. The atom efficiency is therefore 100%. Also, mass economy calculation can be performed to show how n-butane route is more mass efficient. Molar mass of maleic anhydride = 98.11g/mole For 2 moles of anhydride, molar weight = 2 mole X 98.11g/mole = 196g Molar mass of benzene = 78.114g/mole For 2 moles of benzene, molar weight = 2 moles X 78.114g/mole = 288g Total Mass of raw materials = 288 + 156 = 444g The mass efficiency or atom economy of benzene = 196/144 X 100 = 44% This means that only 44% of raw materials is utilized in the product. By similar calculation, atom economy of n-butane is 58%. Benzene route produces CO2 which is a pollutant and in addition benzene is more expensive. It can therefore be said that n-butane route is a more sustainable and environmentally friendly production route. The use of n-butane in this case is an approach to sustainable raw material.

7.2.2 Sustainable Manufacturing Process Sustainable manufacturing is the creation of manufactured products through economically sound processes that minimize negative environmental impacts while conserving energy and natural resources (United States Environmental Protection Agency). It is a clearly thought out manufacturing process that would reduce energy use, emissions, and consumption of finite materials. Most of the strategy to achieve a sustainable (efficient) manufacturing process are derived during the design stage. However, detailed design does not create perfect process, as a result, process improvement study is a continuous activity. Sustainability in manufacturing is therefore a continuous improvement process. There are several tools for evaluating sustainability in a process system. They include the life cycle analysis/assessment (LCA), the material flow analysis (MFA), the energy-based sustainability index (ESI), and ecological input/output analysis (EIOA), among others. LCA is the most appropriate tool for comprehensive and quantitative assessments that captures the direct and indirect environmental impacts associated with a given product or process. This tool standardized by the ISO 14040, 14041 and 14044 has been internationally accepted (Sadhukhan et al., 2014) [121].

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Extraction of Raw Materials

Recovery

Disposal

Recycling of Materials and Components

Design and Production

Reuse

Use and Maintenance Packaging and Distribution

Figure 7.4 Product LCA (Reproduced with permission from Prof. Dr. A. Irabien, Department of Chemical Engineering, University of Cantabria, Santander, Spain).

LCA can be used to find the environmental and social impact associated with developing a product, processes, or related activities, by identifying and quantifying energy and material resources used and wastes and emissions released to the environment. This is now being tackled as an optimization problem based on an objective function that can weight the three components of sustainable development. Application of life cycle thinking in chemical process design will involve the identification of the operating units, finding the sustainability indicators to be used in the operating units and the weight factors to be applied in the definition of the objective function to be optimized. A study team in an oil services company carried out an LCA for one of their important products, the packer module, which utilizes trichloroethlylene (TCE)—a hazardous chlorinated solvent. The module is used as a seal between the tubing and casing, which is a typical tool used in the completion of oil and gas wells. Upon the use of statistical data analysis, the team derived an optimal design that eliminated the use of TCE, and also achieved improved product performance. Linear programming modeling of a mathematical tool that can be used to determine the optimal values of the decision variables of a given set of objectives. In the complex chemical processes, finding the optimum operating points of

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the multiple conflicting objectives, given the various economic and environmental constraints, is very important for the profitability of chemical plants (Mosavi, 2010) [122]. Ghenai (2012) [123] describes the steps for life cycle analysis to include: • Definition of the goal and scope of the assessment – determine why the assessment needs to be done; • What is the subject and which aspect of its life are assessed? • Compile an inventory of applicable inputs and outputs: state the resources being consumed • (Bill of materials); What are the emissions generated? • Evaluate the potential impacts associated with those inputs and outputs; • Interpret the results of the inventory analysis and impact assessment phases in • Relation to the objectives of the study: explain what the result means and what needs to be done about them. A similar tool to LCA is the Lean Six Sigma, which has been described as a sustainability technique. Lean’s focus on waste (non-value-added activity/ output) elimination to increase productivity and efficiency leads to an operational setting that uses less energy, water, materials, equipment, space and human effort [118]. The value derived is not just in the area of waste elimination that leads to increased productivity and profitability, but also in the area of reducing environmental impact. Following implementation of this technique in an oilfield services company over a five-year period, a significant benefit was recorded, which included saving an average of 2378000KW-hr electricity, 19704000L water, and 521T of waste eliminated, reused and recycled. The technique generally improves manufacturing process, conserves resources, recycles and reuses wastes and reduces impact to the environment. For instance, introducing changes to a plating plant process could reduce down-time for plant maintenance, and could reduce procurement of chemicals and the rate at which wastes are disposed.

7.2.3 Sustainable Consumption/Behavior Sustainable consumption involves avoiding overexploitation of renewable natural resources; halting loss of biodiversity; avoiding waste generation and enhancing efficient use of natural resources by applying the concept of life-cycle thinking and promoting recovery, reuse and recycling. Sustainable consumption is not about consuming less but consuming

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efficiently. Regulatory bodies, through government and United Nations’ agency, play very important roles toward sustainability. Ideally, the critical parameter of interest to the engineer is economic consideration; use of renewable resources and minimization of industrial emissions can be a matter of principles and responsibility. To checkmate this tendency, regulatory bodies have imposed penalties, in monetary terms, to be paid for any measurable unit of pollutants released to the atmosphere. For example, there has been a high incidence of gas flaring by international oil companies (IOCs) that operate in the Niger Delta area of Nigeria, West Africa. It appears to be more economical to just flare the associated gas that forms part of the output of oil production and seems to support the reason why gas flaring was rampant. In a bid to drastically reduce gas flaring, a government regulatory body (supported by an act of legislation) decided to impose a penalty on a given quantity of standard cubic feet of gas flared. The regulation stipulates a penalty of $3.5 for every 1000 standard cubic feet of gas flared. This policy became an economic factor of interest that has forced IOCs to start investing in associated gas recovery and processing. The blended gas is sold and utilized in power generation.

7.3 Sustainability in Chemical Engineering Sustainability is a holistic approach that belongs to the entire system and is beyond the process design stage. Sustainable process analysis involves a simultaneous consideration of all the relevant individual stages of a given process system under a life cycle approach. Figure 7.5. shows a truly sustainable chemical engineering design model.

Sustainable Raw Materials

Sustainable Process Synthesis and Design

Sustainable Manufacturing Process

Sustainable Product

Sustainable Utilities

Figure 7.5 Sustainability in Chemical Engineering Model.

Sustainable Consumption

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The all-inclusive design considers the sustainability of the raw materials, sustainability of the process utilities and sustainability of the manufacturing process, leading to the sustainable products. Sustainable consumption is also an important area of consideration for the process designer, hence, the engineer must specify and recommend product consumption procedure that is consistent with sustainability of the entire system. The system therefore becomes sustainable at steady state. The solution creates a system with constant sustainability variables that will not change with time, despite the ongoing processes that strive to change them. Creating a sustainable process system will imply integrating the emerging cutting-edge technologies in the frontier research, which include process systems engineering, process intensification, process integration, product design, nanotechnology, catalysis, and molecular biology (see Chapter 8 for more details). These are the evolving chemical engineering knowledge areas that will ensure sustainable solutions. The process design stage is where the chemical engineer can directly alter the process and product aspect that can advance indirectly the sustainability of the entire product life cycle. The engineer designs the process including the production or manufacturing process. The design stage involves finding process routes, defining unit operations and process controls system that can yield optimal sustainability solution. Li & others (2016) [124] for example, developed a novel process system engineering framework that couples advanced control with sustainability evaluation for optimization of process operations to minimize environmental impacts associated with products, material and energy. Process design has requirements that define the properties of materials to be used in a process. Material property requirement can be thermal (diffusivity, conductivity, expansion, heat capacity), electrical (dielectric constant, electrical conductivity), mechanical (toughness, strength, stiffness), chemical (corrosion resistance) optical (absorption, refraction) and magnetic. To have sustainable materials, different sub-systems taking part in the material supply chain can be harmonized. Sustainable process design also creates a system that utilizes energy efficiently. Most of the energy fed to the point of use in a process system is normally lost in conversion or transmission. A method to ensure conservation, use and reuse of energy is a sustainable process design objective. Sustainable product development processes involve adopting clean manufacturing processes that will reduce the use of raw materials and process utilities. The chemical engineer considers and designs efficient processes that can be sustainable. The critical requirement for successful operation of a process facility is a sustainable (efficient and reliable) utilities and utility systems. They include

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clean compressed air, electricity (power needed for pumps compressors, air coolers, instruments, lights, etc.), sterile gases, inert gas supply (commonly from nitrogen), fluids for process heating (clean steam, hot oil or specialized heat transfer fluid), process water, fluids for process cooling/ temperature control, fuel for fired heaters, chemical injection system, and so on. Hence, sustainability in manufacturing process will entail integrating utilities that are sustainable into the manufacturing process. Sustainable products are those products that can be used and partly or entirely reused for environmental, social and economic benefits and at the same time protecting public health and environment over their life cycle. There is an increasing attention to product remanufacturing and reuse which impacts new ways of consumption. The process engineer, during the design stage, introduces recyclability as a constraint to design in order to achieve a sustainable product. Chemical engineers approach sustainable consumption during the design stage by paying attention to the social dimension of well-being. The engineer during the design can anticipate and alter the choices the consumer has in order to support sustainable consumption. Eco labeling of products is also another way design engineers contribute to sustainable consumption. Furthermore, policy and design are closely related, while policy can form a constraint to design, policy is also informed by design outcomes. Ultimately, a sustainable design and sustainable manufacturing process that leads to a sustainable product will yield sustainable consumption. From the sustainability model, it can be established that when integrating sustainability in chemical engineering product design, operative, tactical and strategic sustainability development criteria need to be considered. Venselaar (2001) [125] highlights specific innovative development for sustainable process engineering to include: • • • • • • • •

Membranes Supercritical processes such as extraction with CO2 Bioprocess technology Catalysis Micro reactors Biomass conversion into energy carriers, base chemicals. Photovoltaic energy, e.g., based on organic Polymers

Any optimal process engineering solution is a sustainable solution. A professional chemical engineer, La Porta (Doyle, 2018) [126] stated that the greatest way to reduce the environmental impact of a process facility

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is to optimize the process itself. In other words, any quality chemical process design can be said to be sustainable. That is, any design solution that reduces carbon footprint can be said to be a sustainability achievement. Schlumberger process segment for example, in trying to adhere to disposal regulations, developed optimized produced water treatment solutions that deliver increased capacity and performance in a reduced footprint (up to 50% smaller footprint). The unit known as Dual Compact Flotation Unit, incorporates residual flotation gas in a secondary separation stage to increase oil-in-water removal efficiency while fully degassing the clean water outlet (Fig. 7.6).

Figure 7.6 Dual Compact Flotation Unit. Sourced at https://www.slb.com/services/ processing-separation/water-treatment/oil-removal/epcon-dual-compact-flotation-unit. aspx. Credit: Schlumberger.

It can be observed that some chemical engineering researchers have taken an interest in emphasizing sustainability in their design problems. Most times energy and pollution reduction is the target, and any process solution that directly reduces energy generated indirectly from fossil fuel and/or reduces pollution to the environment can be viewed as a sustainable design solution. Meanwhile, any quality design done in this area of specialty must have also considered other sustainability design constraints, which are economy, safety of life and societal need. However, sustainability research has introduced sustainability evaluation metrics, increased focus on supply chain and life cycle thinking. Although these engineers in addition, do engage in selective study of finding ways of eliminating impact to the environment and life. In this case, the research is not a design research but rather a process synthesis and analysis research. The modern chemical engineering research community has called sustainability design an area of specialty. Hence, we have such research descriptions as “integrating sustainability in chemical engineering design”,

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“sustainability in chemical engineering”, “new trend for design toward sustainability in chemical engineering,” and so on. Ironically, the author in this book has also discussed sustainability design, but in a separate chapter from the design and chemical engineering practice discussed in Chapter 5. Efficiency, optimization and sustainability indeed mean the same thing to the chemical engineer but due to the criticality of the sustainability question, emphasis on the term “sustainability” in chemical engineering will continue for a long time. It is the author’s firm belief that in the future every chemical engineering design will be based on sustainability consideration such that the use of the term “sustainability integration in design” will no longer apply. Hence, global environmental responsibility, broader scope of economic return, considering wealth creation and social development will form key design constraints in every design, leading to an increase in engineering competence, methods and tools for design and engineering. Sikdar (2004) [127] listed four types of tools needed in developing a sustainable system. The objective of the design will determine if one of the four or all four types might be applied in designing a sustainable system. The tools are: 1. Metrics tools; for measuring progress toward sustainability, 2. Analytical tools; for problem identification, problem analysis, and decision making for design, 3. Process tools; for designing unit operations and processes, and 4. Economic tools; for assessing the incentives for cleaner practice

7.4 Chemical Engineering Sustainability Design and Research Problems The following are a few examples of chemical engineering design and research problems that emphasize sustainability: • The manufacture of microelectronic devices for the semiconductor industry will require ultrapure chemicals that are ultra-purified. The design engineers are required to find an ultra-purification alternative that would consume minimal energy, with less impact to the environment.

Sustainability in Chemical Engineering Design • Electrochemical valorization of CO2 – Study of power-togas approach in analyzing the environmental rationality in terms of the carbon footprint of a photovoltaic solar powered electrochemical reduction process for the utilization of CO2 as carbon source for the production of CH4. • Application of miniaturized analytical tools, including microfabricated chemical devices for the manufacture of hazardous chemicals where material storage and transportation can be avoided. • Design of inherently safe but flexible and multiproduct plants. • Finding the optimum operating points of a multiobjective complex chemical processes, given the various economic and environmental constraints (see Mosavi, 2010 [122] for further review). • Finding ways to tackle the CO2 issue by way of capturing, storing or converting the CO2 into valuable chemicals, e.g., the recycling of CO2 by electrochemical reduction (artificial photosynthesis). • Program on the systematic development, testing, and global integration of methods and tools for the design of products with superior life cycles. • Development of an improved eco-efficient and effective system (through intelligent raw materials and energy utilizations, integration of emerging product development technologies, and economic optimization). • Catalysis and sustainable reaction engineering – design of new materials (electronic, optical, soft and biological materials); creating new classes of porous oxide catalysts; designing highly efficient processes that are also more environmentally friendly. • Innovative production of advanced biofuels and renewable chemicals from waste – technology that can convert nonrecyclable, non-compostable municipal solid waste into ethanol, methanol and other valuable chemicals. • Solvent and catalyst optimization; rigorous simulation for analyses of process configuration, costs and thermodynamic properties of a process stream. • Etc.

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7.4.1 Key Challenges The challenges for the chemical process engineers in achieving sustainable design solutions are enormous. The Harold and Ogunnaike (2000) [128] articulated list of sustainable design challenges has been elaborated to include the following key challenges: • Inherent safety and environmental friendliness • Inherent robustness and “six sigma” – meaning that process must be operable, economically viable and must lead to products that consistently meet customer quality demands as determined by the metrics of “six sigma” • Flexibility in multiproduct and distributed manufacturing • Innovative process synthesis and design for reduced capital and cost intensity • Synthesis and design of new product • Synthesis and design of small-scale chemical systems.

7.4.2 Technologies for Sustainability Various innovations and developments are ongoing in the field of sustainability. Engineers through industry-university collaboration have developed advanced technology for energy conservation and pollution prevention known as Chemical Complex and Cogeneration Analysis System. The system can be used to design energy efficient and environmentally suitable plants and create new products from greenhouse gases. The system combines the chemical complex (Multiplant) analysis system with the cogeneration design system. The cogeneration design system examines commercial energy use in multiple plants and derives the optimal energy use based on economics, energy efficiency, regulatory emissions, and environmental impacts from greenhouse gas emissions (Pike, 2006) [129]. The system is coupled with a sophisticated computer program which solves a mixed integer nonlinear programming problem for optimum configuration of complex chemical process plants. Interaction with the system is via a graphical user interface designed and implemented with visual basic. The program considers equality constraints which includes material and energy balances, rate equations, and equilibrium relations for the plants, and inequality constraints such as process unit capacities, availability of raw materials, and demand for product. The term Cogeneration can be defined as a highly efficient and ecologically valuable technique of power generation consisting of the effective

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consumption of waste heat while producing power. By utilizing the waste heat, fuel energy utilization efficiency can be as high as 90% during this heat and power generation process. CO2 is produced during the operation of fossil fuel electricity generation systems. For example, over Ikg of CO2 is produced and over 1.5kWh of thermal waste heat is rejected to the atmosphere for every kWh of electricity generated from coal; and electricity generation from natural gas produces 0.5kg of CO2 and 1.5kWh of thermal waste heat.

8 Chemical Engineering Computer Software Tools and Applications 8.1 Introduction Microsoft Excel, MATLAB, Aspen HYSYS, PRO/II, UNISIM, and so on, are used to solve typical chemical engineering problems—solving realistic problems and exploring alternatives that would be difficult or inaccessible for hand calculations. They include equations of state, chemical equilibrium of simultaneous reactions, phase equilibria, plug flow reactors, heat transfer in 1-Dimensional, and time-dependent heat transfer, process and product synthesis, process design, process dynamics, control and monitoring, regression of kinetics of complex reactions, solving ordinary differential equations, optimization, and so on. Technical tools such as flowsheet editors, simulators for steady-state and dynamic simulations, among others, are crucial aids for effectively and efficiently performing design tasks. In addition, managerial tools are required which address the coordination of design processes. For example, Project Management Systems, Primavera Project Planning, and others, assist chemical engineering management engineers in planning and controlling complex chemical engineering projects.

8.2 Development of Chemical Engineering Computer Software The history of simulations using computers started in 1946 with the first general purpose computer (ENIAC). John Von Neumann managed the first deployment of this computer, the purpose of which was to model the process of nuclear detonation during the Manhattan project. Later, an attempt at simulating chemical process engineering systems started in the

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early 1950s. The late 1950s saw one of the most significant developments of the FORTRAN programming language. In 1964, the digital computer program PACER, which was written in FORTRAN, was developed. It was only in 1966 that simulation sciences commercialized a computer program for economic evaluation and design of unsteady-state processes. Memory size and computational speed of digital computers increased in the 1960s. High-speed digital computers for solving complex chemical engineering problems started arriving in the 1970s. Hence, integrated process flowsheet package programs like Monsanto’s FLOWTRAN, PACER, ICI’s FLOWPACK and Kellogg’s flexible Flowsheet, were developed. IT development started with small software houses such as CHEMSHARE. As at 1982, these companies were leasing to large companies their process simulation programs in mainframe computers. COADE, one of the software houses, was trying to market the process simulation program “MICROCHESS” for Personal Computers at the time. Personal computer programs were also at the time improving very fast, just at the same speed as the development of the personal computers. COADE eventually separated into two firms, namely Chemstations, Inc. and COADE, Inc. While Chemstations specialized in chemical engineering programs such as CHEMCAD and other additional programs linking with it, COADE continued with design programs such as CAESAR-II (Pipe Stress Analysis), Pressure Vessel, and so on. Later, in the 1980s, other specialized software houses such as Chemshare Hysis, ProSim, Aspen and others came with chemical process simulation programs for mainframe or mini-computers. Development of PC made them change their programs to PC format. Some of the packages developed at the time include ASPEN, DESIGN II, SIMSCI (PRO/II), CHEMCAD and HYSYS. Each of these software programs was designed for typical use such as equipment design, economic evaluation (cost estimation), sensitivity analysis, process modeling, optimization, etc. The development of computers over the years allowed better analysis and understanding of chemical processes. Nowadays most chemical engineering textbooks contain computer software applications of engineering computations compared to previous editions. In the 1990s, all major software packages passed through periodic upgrades and transformations. These days, chemical process simulators are developed on programming languages such as C#, C++, MATLAB or Java. Thus, some of the computer software that is widely applied in solving chemical engineering problems includes HYSYS Process Engineering Design Software, PRO/II Process Engineering Design Software, Statistical and Numerical Analysis Software (Microsoft Excel Spreadsheet), Computer

Chemical Engineering Computer Software Tools and Applications 297 Programming and Control Software (MATLAB and Visual Basic), and Computer-Aided Design & Drafting (Auto-CAD). Presentation Software used for presenting technical reports is also an important software to chemical engineers. Also, most chemical engineering design books now include CD-ROM tutorials with solved examples using the process simulator software. New versions or upgrades of these software programs are continually being developed. Consequently, newer software programs are being developed that would be smarter than the existing ones and in the next decades, more upgrades and transformations will be expected.

8.3 Process Engineering Design Software (HYSYS and PRO II) 8.3.1 HYSYS Process Engineering Design Software HYSYS is the most widely used powerful process simulation and modeling software in the industry. It is now being introduced in universities and colleges. The software is used to solve numerous complex engineering problems in the oil & gas production, gas processing, and petroleum refining industries. It is also used to optimize designed processes and model existing plant processes to achieve more reliable and stable operations. Process engineers are faced with the challenge of making timely business or investment decisions while meeting the business objectives of designing and operating efficient, safer and economical viable process plants. Also, for the process industry to remain competitive and maximize business performance, engineers must identify optimum designs quickly with minimum risk of rework. Basically, chemical engineers who work as process design engineers can use the software to model a process for steady-state simulation, design new production process, monitor performance, and optimize existing or synthesized process. Engineers also use this software to conduct a quick research for oil & gas production facility modification or upgrade and for front-end engineering design (FEED) studies. Figure 8.3.1 shows a process flow diagram (PFD) built in a HYSYS simulation environment. The chemical engineer applies this software in the following ways: • Improvement of productivity and profitability throughout the plant life cycle. Based on simulation and analysis tools features, real-time applications and the integrated approach to the engineering solutions in HYSYS, companies can

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SEPRT1 S8 S3

S9 GASEOUT

S2 S1

COAL

S4 STEAM RGIBBS

RYIELD SEPRTR

S6

S5

CYCLONE

O2

STOICHIO MIXER SOLIDS

Figure 8.3.1 Simulation of Coal Gasification Using Aspen Plus. [158]

improve designs, optimize production and enhance strategic business decision making. • By creating different scenarios, engineers can evaluate various process alternatives or routes using HYSYS. Hence, optimal solution can easily be selected for new designs. The software has an interactive environment which allows for easy ‘what-if ’ and sensitivity analysis. • Also, engineers can model an existing process plant, simulate the production process to determine whether any equipment is performing below specification or not. This is mostly needed when engineers are troubleshooting to ascertain why plant capacity has dropped or why undesirable product is being produced. Equipment deficiencies can occur because of many reasons such as fouling in heat exchangers, flooding in columns, overpressure in separation equipment, and so on. Figure 8.3.2 shows a HYSYS simulation of a centrifugal compressor unit.

8.3.2 PRO II Process Engineering Design Software Overview PRO/II is also another computer simulation system and as described in Wikipedia, is a system for process engineers in the chemical, petroleum, natural gas, solids processing, and polymer industries. PRO/II optimizes plant performance by improving process design, revamp and operational analysis and performing engineering feasibility studies. The tool includes a chemical component library, thermodynamic property

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Figure 8.3.2 HYSYS simulation of a centrifugal compressor unit (Aspen Technology 2013). * The software is particularly useful during process scale-up.

prediction methods, and unit operations such as distillation columns, heat exchangers, compressors, and reactors as found in the chemical processing industries. It can perform rigorous steady-state mass and energy balance calculations for modeling continuous processes and a wide range of chemical processes. Hence, PRO/II offers the chemical, petroleum, natural gas, solids processing and polymer industries a comprehensive process simulation solution.

Figure 8.4.1 Distillation Column Simulation (Credit: Invensys SimSci-Esscor PRO/II v9.2)

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Introduction to Chemical Engineering Key Benefits • Designs new processes • Thoroughly evaluates process improvements before committing to costly capital projects • Cost effectively assesses, documents and conforms with environmental requirements • Improves plant yields through the optimization of existing plant processes • Provides fast-track process troubleshooting • Detects and remedies chemical process bottlenecks

Key Capabilities • Refining applications – heavy fossil fuel processing, crude preheating, crude distillation, Fluid catalytic cracking (FCC) main and coker fractionator, naphtha splitter and stripper, sour water stripper, sulfuric and HF acid alkylation. • Pharmaceutical applications – batch distillation and reaction. • Oil & Gas Processing applications – gas dehydration, amine sweetening, cascade refrigeration, compressor trains, deethanizar, demethanizer, hydrate formation/inhibition. • Chemicals/Petrochemical/Life Science applications – ethylene fractionation, biofuels, aromatic separation, cyclohexanes, MTBE separation, naphthalene recovery, C3 splitting, olefin and oxygenate production, phenol distillation, dehydration processes, ammonia synthesis and propylene chlorination. • Chemical applications – liquid-liquid extraction, ammonia synthesis, azeotropic distillation, biofuels, crystallation, dehydration, electrolytes, inorganics, phenol distillation, solids handling. • Polymer applications – free radical polymerization, stepgrowth polymerization, copolymers. Key Features • • • •

Has built-in integration with Microsoft Excel; Has customizable process modeling via Microsoft spreadsheet; User can create and manage custom data; Contains comprehensive thermodynamics and physical data;

Chemical Engineering Computer Software Tools and Applications 301 • Comprehensive unit operation modeling – general flowsheet models, heat exchanger, reactor, distillation, etc., flowsheet control; • Integration with other industry-standard software; • Has application across various chemical, oil and gas, petrochemical, pharmaceutical industries, and so on.

8.4 Statistical and Numerical Analysis Software 8.4.1 Engineering Computations Using Microsoft Excel Microsoft Excel is an application that features calculation, graphical tools, tables, and a macro programming language, Visual Basic. Excel is widely used in the industry. There are many textbooks and online tutorials available for Microsoft Excel and the “Help” tool within Excel itself can serve as a training guide. A given data set can be analyzed with Microsoft Excel, simulating measurements made of a single parameter. This data set can be characterized using the Descriptive Analysis and Histogram tools contained within the Data Analysis package. Chart can be used to show trend. Also, the mean, median, range, standard deviation, variance, kurtosis, skewness, 95% confidence limits, and the frequency and cumulative histogram can be calculated. Case Example To describe engineering computation using Microsoft Excel, consider a set of data which describes the historical operating parameters of a fluid catalytic cracking unit (FCCU) of a petroleum refinery in Nigeria. Thousands of these data were manually transferred to excel for analysis to understand the trend in the unit’s operation and possibly develop a statistical equation which will serve as a model for explaining the interactions between these operating controllable parameters. FCC operating variables can be grouped into dependent and independent variables. Many operating variables, such as regenerator temperature and catalyst circulation rate, are considered independent because operators do not have direct control of them. Dependent variables are those over which the operators have direct control, such as riser outlet temperature and recycle rate. Using some statistical functions which is beyond the scope of this book, controllable variables such as feed rate, feed temperature and reactor temperature were identified as key variables affecting yield in the FCC unit. The data generated was first reduced to average values using Excel as shown in the following Figure 8.5.1.

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Figure 8.5.1 Various Operating Conditions Data.

Also, conversions at various operating conditions for a given temperature value were determined and plotted as shown in Figure 8.5.2.

Figure 8.5.2 Conversions at Various Operating Conditions.

Average Values of the dependent variable (y) for all values of the independent variable(s) (x1, x2, etc.). Where y1 = gasoline yield (m3/h), x1 = Feed Rate (m3/h), x2 = Feed Temperature (oC), x3 = Reactor Temperature (oC).

Chemical Engineering Computer Software Tools and Applications 303 Therefore,

y1 = ao + a1x1 + a2x2 +a3x3, Where a0, a1, a2, a3 are unknown constants to be determined using LINEST function in excel. The result of the model equation for gasoline production in the FCCU derived by applying the function is hence:

y1 = -660.81 + 0.49218x1 – 0.2809x2 + 1.38289x3

(8.4.1)

The following Figure 8.5.3 shows the LINST function formula and results:

Figure 8.5.3 LINST function results.

8.5 Computer Programming and Control Software (MATLAB and Visual Basic) Optimization is a technique in chemical engineering to find the most efficient and effective process within a given constraints. Chemical processes involve a large number of variables with a large number of constraints. Hence, manually solving these problems can be difficult. Computer models have been developed to be used in solving these optimization problems.

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Some of the commercial software available include MATLAB, Visual Basic, and so on. Solution of Equations Using MATLAB MATLAB stands for Matrix Laboratory. Hence MATLAB operations rely on matrices. It is used in solving algebraic and trigonometric equations, both single and several at the same time, both linear and non-linear. Equations based on, for example, the equilibrium relationships for a chemical reactor making NO2 from NO and O2 as part of an existing plant that produces variety of chemicals can be solved applying MATLAB. Case Example A practical example of chemical engineering computer application using MATLAB can be seen in one of the author’s postgraduate research works entitled, “Analysis of a Petroleum Refinery’s Fluid Catalytic Cracking Unit to Optimize Unit performance”. Both excel spreadsheet and MATLAB program were used extensively in solving the problem. To solve the optimization problem, thousands of operating parameter data was extracted from the unit’s operations log books for the period of 1989 to 2002. LINEST function in excel spreadsheet was used to generate a model equation for the FCC unit. FCC units process heavy oil from a variety of refinery flow schemes. Generally, the feed comes from either the refinery crude unit (atmospheric gas oil, AGO) or vacuum unit (vacuum gas oil, VGO) and constitutes the fraction of the crude boiling in the range of 650 to 1000 oF (350 TO 550+  oC). The AGO and VGO are further treated before they are charged as feed to the FCC unit. (See Figure 8.6.1.) The products obtained from the FCC are light hydrocarbon gases (C2+) which are normally used within the refinery as fuel gas, light olefins and paraffins (C3’s and C4’s) also referred to as LPG, gasoline, light cycle oil (LCO) and clarified oil (CLO) sometimes referred to as main column bottoms. Heat is recovered from the flue gas and is used to make steam. In some cases, power is also recovered from the flue gas in the form of electricity via a power recovery expander coupled to a motor/generator. Main column bottoms or light cycle oil are utilized for fuel oil, it is normally used as a blending component in the diesel pool and/ or in the heavy fuel oil pool. In some cases, FCC clarified oil is used in coker feed, for asphalt production or sold as feed for carbon black production. LPG is used for fuel, and fuel gas for fired heater/boiler fuel. Yields vary considerably with feed and catalyst properties, as well as operating conditions. Most of the FCC product streams undergo further processing before leaving the refinery as marketable products.

Chemical Engineering Computer Software Tools and Applications 305 C4 and Lighter Gases

Crude Fract.

Gasoline and Lighter

Straight Run Gasoline Kerosene

Crude Oil

Atmospheric Gas Oil

LCO FCC

Vac. Fract. Atmospheric Residue

Vacuum Gas Oil

CSO Hydrotreater

Demex

Vacuum Residue

Figure 8.6.1 Refinery Process Flow.

The LPG from an FCC unit is highly olefinic and has become an increasingly valuable stream for further processing in the present movement toward reformulated gasoline. FCC olefins are an important feedstock for the production of MTBE and alkylate as gasoline blending components. The actual C3/ C4 paraffins that go into the LPG pools in the refinery are sold to a petrochemical company, to be used as feedstock in the production of petrochemicals such as plastic pallets, and so on. The refining company’s FCC unit has been designed to produce a maximum quantity of gasoline, from a light vacuum gas oil. FCC gasoline generally has good octane properties (90-95 RON and 80-83 MON) and may make up 30 volume % or more of the refinery gasoline pool. FCC Process Flow A typical FCC unit comprises two interconnected fluidized bed reactors: the riser reactor, in which almost all endothermic cracking reactions occur, as well as coke deposition in the catalyst pores, and the regenerator, in which air is used to consume the coke deposits by burning. The heat produced is carried by the catalyst from the regenerator to the riser. Besides reactivating the catalyst, the regenerator supplies almost all the

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heat required by the endothermic cracking reactions. The process is very complex, one of the reasons being the interaction between operating variables from both reactors. Operating Variables There are a large number of variables in the operation and design of an FCC unit that may be used to accommodate different feed stocks and operating objectives. Operational variables are those that may be manipulated while on stream to optimize the FCC performance. Decisions of design variables must be made before the unit is constructed. FCC operating variables can be grouped into dependent and independent variables. Many operating variables, such as regenerator temperature and catalyst circulation rate, are considered independent because operators do not have direct control of them. Dependent variables are those over which the operators have direct control, such as riser outlet temperature and recycle rate. Using some statistical functions which are beyond the scope of this book, controllable variables such as feed rate, feed temperature and reactor temperature were identified as key variables affecting yield in the FCC unit. Objective The overall objective of the research performed in the FCC unit, applying the MATLAB and spreadsheet, was to determine the actual controllable variables impacting on the yield of gasoline and consequently, determine optimal values of the actual key controllable (dependent) operating variables that will lead to optimal yield. Designed range of operating conditions, feed and product yields for the unit is shown in the following table. The volume percentage of products produced in the FCCU is calculated from the raw data. The equation below is used for this purpose:

Vol% of Product i = Yield of Product i/Total Yield * 100 (8.6.1) Also, conversion is calculated from the raw data with the following equation:

Conversion = 100 * 1 – (MCBP + LCO)/Raw Oil Charge, BPD (8.6.2) Conversion is a measure of the degree to which the feedstock is cracked to lighter products and coke during processing in the FCC. It is defined as 100% minus the volume percentage yield of LCO and heavier liquid products. In general, as conversion of feedstock increases, the yields of LPG, dry

Chemical Engineering Computer Software Tools and Applications 307 Table 8.6.1 Range of Operating Conditions, Feed and Product Yields in PRCL FCCU.

Product Yields (m3/h)

Feed and Operating Conditions (°C), %

Min (a)

Max (b)

Designed

Variation (b) - (a)

Gasoline

80

156

150.54

76

C3 LPG

7

30

29.54

23

C4 LPG

15

44

45.12

29

LCO

18

50

47.4

32

MCBP

7

24.5

23.35

17.5

Feed Rate, m3/h

145

266

264.9

121

Feed Temp.

205

234

232

29

Rx Temp.

525

534

532-535

9

Rg Temp.

600

700

680

100

Rg Cat Level

19

70

30-40

51

gas, and gasoline will increase, while the yields of LCO and fractionator bottoms decrease. Conversion can also be defined as “the volume percentage of the gas oil change which is cracked to products other than gas oil”. The average volume percentage of LPG, gasoline, LCO and MCBP respectively, produced as calculated from the raw data using Equation (8.6.1) is plotted against conversion as shown in Figure 8.6.2. 70.00

60.00

50.00

Products, Vol%

Vol% of G Vol% of LPG

40.00

Vol% of LCO 30.00

20.00

10.00

0.00 72.00

73.00

74.00

75.00

76.00

77.00

Conversion, %

Figure 8.6.2 Products, Vol% against Conversion, %.

78.00

79.00

80.00

81.00

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The model equation developed for gasoline yield is:

y1 = -660.81 + 0.49218x1 – 0.2809x2 + 1.38289x3

(8.6.3)

Where y1 = gasoline yield (m3/h), x1 = Feed Rate (m3/h), x2 = Feed Temperature (°C), x3 = Reactor Temperature (°C)

Figure 8.6.3 MATLAB Computer Program for Optimal Yield of Gasoline.

Figure 8.6.4 MATLAB Computer Program Solutions for Optimal Yield of Gasoline.

The result of the research shows that feed rate, feed temperature and reactor temperature are the main controllable (dependent) variables affecting yield of gasoline in the FCC unit. The MATLAB program shows the optimal values of the units’ key controllable operating variables that will lead to optimal yield of gasoline.

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8.6 Computer-Aided Design & Drafting (Auto-CAD) For about two decades, professionals in various engineering fields have used AutoCAD software for a wide range of applications. ComputerAided Design and Drafting software is another very useful design tool used by chemical process design engineers. CAD is a broad term covering a variety of more specialized roles including computer aided industrial design (CAID), computer-aided engineering (CAE), computer-aided manufacturing design (CAM), Computer-Aided Molecular Design (CAMD). AutoCAD falls into the category of programs known as Computer-Aided Design (AutoCAD) or CAD software. It has effectively replaced traditional manual technical drawing modes, such as hand drafting. Another benefit of CAD software is enhanced visualization, which helps in the commercial sales of design projects. The software has been available since the early 1980s and presently features a host of applications, including: • • • •

2-Dimensional (2D) drafting, drawing, and annotation 3-Dimensional (3D) modeling and visualization Project documentation User Interaction – launch commands and respond to prompts and so on. • Collaboration – share and reuse data from PDF, insert/ import geographic location information, display map from an online map service, and so on. • Others

Typical deliverables of a CAD system in a 2-Dimensional (2D) application in process industries include: • Process flow sheets (PFD) • Material take-off (Bills of material otherwise known also as bill of engineering measurement and evaluation (BEME)). • Piping (Process) and Instrumentation Diagram (P&ID) • Unit plot plan and plant layout. • Piping layouts and piping isometrics • Scope drawing for process equipment • General arrangement drawings • Structural drawings • Cable routing and layouts, and so on.

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The capabilities and resolution of commercial three 3D-CAD systems have increased intensely, and it is now possible to swap the physical model often used during conceptual design with a computer-generated model with a walk-through facility. Typical deliverables of a 3D-CAD system include: • Detailed engineering drawings such as plan and elevation drawings, bird’s-eye views. • 3D-CAD model • Piping isometrics • Material take-off (MTO) • Shaded perspective views separated in logical areas, e.g., units (model review) • Reports such as line lists, instrument data, interference checks (clashes), mock-ups.

Figure 8.7.1 A 3D-CAD model of a proposed process plant.

Presently, the application of 3D-CAD technology in process plant design allows for the following: Definition of classified 3D-shapes to show envelopes for: • • • • • •

Safety Area classification zones Head room/tripping hazards Access/escape corridors Valve hand wheels Reach/clearances for activities

Chemical Engineering Computer Software Tools and Applications 311 Access envelopes for: • • • • •

Maintenance equipment Operability Identification of deviations from normal engineering practices Modeling of foundations and underground systems Consistency between the 3D-CAD model and the process engineering flow scheme (PEFS).

Project documentation is the rest. CAMD or Computer-Aided Molecular Design is another CAD version of interest. It refers to the design of molecules with desirable properties. One can determine molecules that match a specified set of (target) properties through CAMD. All kinds of chemical, bio-chemical and material products can be designed through CAMD technique. CAMD software is utilized by chemical engineers in pharmaceutical research and provides great insight into the structure and activity of drugs. The software automatically generates molecular structures and one can restrict types of chemical designed by eliminating all structural groups which are not desirable. Also, physical properties of all generated structures. Using group contribution estimation techniques enables CAMD software to determine new compounds. Also, target physical constraints, such as boiling and melting points can be determined. Application – CAMD software can be used to find for a toluene substitute (an environmentally friendlier solvent), for example.

8.7 Piping and Equipment Design Software CAESAR II This software is useful for engineers who want to specialize in piping design for process plants. Some chemical engineering graduates who choose to specialize in this area will find the software very helpful. CAESAR II is the Pipe flexibility and stress analysis standard against which all others are measured and compared. The CAESAR II spreadsheet input method revolutionized the way piping models are built, modified, and verified. It was the first pipe stress program specifically designed for the personal computer environment. The interactive capabilities allow rapid evaluation of both input and output, thus blending seamlessly into the “design – analyze” iteration cycle.

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Figure 8.8.1 Plant Piping Model (Image Source: http://www.chemanager-online.com/ en/topics/plant-engineering-components/intergraph-caesar-ii-2016-better-pipe-stressanalysis-0, 2017).

As with all COADE products (see section 8.2), CAESAR II is continuously maintained and improved by the engineering staff. These are people who have worked in the industry, for engineering and consulting firms. Their experience is applied in program development and in providing the knowledgeable support to users. This is the reason CAESAR II can work the way a typical engineer thinks and solves a problem. The technical support provided to users by the engineering staff is almost instantaneous. Hence, users can talk straight to the developers, insuring an accurate and timely answer. CAESAR II has a wide range of capabilities, from numerous piping codes, to expansion joint, valve & flange and structural data bases, to structural and buried pipe modeling, to spectrum and time history analysis, to equipment and vessel nozzle evaluation. Some of the Operational Features Include: • • • • • • • •

Static and dynamic analysis Menu/spreadsheet interface Intuitive analysis model creation Interactive graphics International piping codes Expansion joint databases Automated stress isometric creation Seismic and support settlement analysis

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Figure 8.8.2 CAESAR II Model (Image Source: http://www.codecad.com/C2Operation. htm, 2017).

• • • •

Integrated error checking Design tools and wizards Wide-ranging material databases Others

8.8 Others Others include presentation and documentation software.

8.8.1 Presentation Software (Power Point) Chemical engineers like other professionals present their report, technical research findings via a PowerPoint presentation program. The newer version of the program has features that make it possible for engineers to communicate technical information effectively. PowerPoint is part of Microsoft Office suite which has been in existence since 1990, although the presentation software has been developed since 1987 and was known as “Presenter” before it was sold to Microsoft. The program has proven to be an effective means of communicating something to an audience—an idea, a business plan, a feasibility design study, a marketing strategy. Engineers use the software program predominantly during program presentation or review, project kick off meetings, project progress meetings, project feasibility and financial case presentation, alternative routes review, and so on.

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Wikipedia published that this program is used worldwide at an estimated frequency of 350 times per second. The application is one of the visual aids for presentation.

Figure 8.9.1 A PowerPoint presentation in progress.

Unique features of PowerPoint that enables effective communication with an audience beyond what can be presented in words include: Animation – Users can create advanced custom slide animation in PowerPoint Colors – Users can select color of their choice to convey their message. Photographs and other images – Pictures and other images can be uploaded and included in the presentation. Tables – Tables can be created or imported Charts – For comparing and presenting data Diagrams – Diagrams can also be created so that the audience can literally visualize a relationship, concept, or idea. Shapes and text-box shapes – Lines, shapes, and text box shapes (shapes with words on them) can be used to illustrate ideas. Sound and video – Sound can be added to the animation and video imported to make presentation a feast for the ears and eyes.

9 Graduate Programs in Chemical Engineering 9.1 Introduction Postgraduate programs in chemical engineering aim to provide graduates with advanced chemical engineering, process technology and production skills for exciting and challenging careers in the chemical, gas and process industries. The postgraduate chemical engineering program emphasizes a review of the chemical engineering principles and advanced contemporary applications of chemistry, biosciences, and advanced mathematics. These programs are formulated to ensure that postgraduates are fully equipped for industry with all the relevant skills they will need from design, problem solving, numeracy and analysis skills to communication, entrepreneurship and leadership skills. The employment prospects for postgraduates are also very good indeed. A postgraduate program in chemical engineering gives candidates the opportunity to embark on any of the varied specialties in the field. From pollution control to engineering education, research to business and finance, safety analysis to product design and energy to process design and marketing management to economic analysis. Candidates have options for specialized studies and research in such areas as nanotechnology, biotechnology, biomedical engineering, bioprocessing, chemical reaction engineering, composite materials, polymers, heat transfer, mass transfer, metabolic engineering, process analysis, thermodynamics, distillation, absorption, extraction, transport phenomena, and diffusion. The specialized M.Sc. streams gives candidates opportunity to explore one area of chemical engineering in more depth. Researches performed in the postgraduate school of Chemical Engineering are geared toward exploring and exploiting foundations of engineering science relevant to the technological and societal challenges facing modern industry and, indeed, our world. Uche Nnaji (ed.) Introduction to Chemical Engineering: For Chemical Engineers and Students, (315–336) © 2019 Scrivener Publishing LLC

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Figure 9.1.2 Chemical Engineering (ChE) Graduate Program.

9.1.1 Master’s Degrees A master’s degree in chemical engineering positions graduates for technical leadership and specialization in industry, providing additional breadth and depth of knowledge. Candidates progressively acquire skills such as analysis, inventiveness, resourcefulness, responsibility and perseverance through research activities. These skills make employees more successful and give them greater opportunity to grow faster in organizations. For a graduate who is more interested in the product and plant design aspects of chemical engineering, a M.Sc./M.Eng would provide an advantage. In a Chemical Engineering master’s degree program, candidates will learn to come up with solutions for problems related to process and product technology. Education and research are closely integrated within this master’s program, which helps graduates stay up-to-date with latest developments within the discipline. In addition, graduates become familiar with all the latest tools and technologies used by chemical engineers in the industry. Chemical engineering graduate students in the M.Sc./M. Eng program will take a number of advanced courses in key fundamental chemical engineering areas such as applied mathematics, thermodynamics, transport phenomena, kinetics and reaction engineering. In addition to the foregoing, students will select a number of elective courses to develop knowledge and expertise in specialized fields such as bioengineering/ biomedical engineering, environmental engineering, engineering design,

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energy engineering, materials engineering, control management and engineering management. Fresh chemical engineering graduates can also return to school to earn their M.Sc./M.Eng. degree in chemical engineering. This is most important especially as there may be no guarantee for a well-paid or choice job readily available for such graduates, especially in some less industrialized countries. Also, after a few years in the field, practicing engineers can return to the classroom to earn their master’s degree in Chemical Engineering. Those who are not yet gainfully employed should be dedicated to a fulltime master’s degree program. Nowadays, given the availability of information technology, professionals may wish to attend online-based chemical engineering postgraduate courses that fit into their schedules. However, an online master’s degree program may span three to five years, depending on an individual’s course load. During this stage of a graduate chemical engineer’s education, candidates are faced with options of narrowing their focus to one or two key specialties. However, some universities do not offer options but rather run the program as general chemical engineering.

9.1.2 Doctoral-Level Degrees A Ph.D. in chemical engineering is most helpful to graduates who want to carry out university research, private research or to teach. Of course, with an M.Sc. one can also start teaching. Nevertheless, individuals with significant professional experience and accomplishments can also delve into teaching and research positions. Advanced degrees can often be costly in terms of finance. On-campus graduate students usually can apply for assistantships which will earn them income to offset academic cost. This is usually another way of eventually becoming a lecturer of the particular university. Postgraduate students upon graduation would develop an advanced knowledge of principal chemical engineering principles and applications, design techniques for the creation of products and process plants to meet a defined need, profit-making and economic aspects, health, safety, sustainability, environmental and other professional issues, management and business practices, ways and means applicable to research and advanced scholarship. A Ph.D. program in chemical engineering encompasses all the advantages of a master’s degree and in addition opens doors to research and development opportunities in academia, industry and government. Ph.D. holders develop independence, creativity and flexibility and consequently are sought out for leadership roles in technical organizations, resulting in more fascinating and fulfilling careers.

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Experienced or practicing chemical engineers who wish to contribute to their industry or state at the highest echelons of both business and academia can choose to pursue a doctoral-level degree. Postgraduate courses in chemical engineering can open up a world of opportunity in career options and employment prospects. Graduate chemical engineers who are smart and research oriented, can advance to pursue a doctoral degree in chemical engineering. The chemical engineering discipline offers a solid professional basis with the opportunity to diversify into a horde of commercial and industrial sectors, and the opportunities are growing. Graduates who desire to be on top of their game in this challenging and dynamic field would normally advance to this highest level. There is a wide range of topics on which chemical engineering doctoral students can undertake creative and relevant research. The focus can be on advancing the science and engineering of complex systems and addressing different scales and levels of complexity. The research on complex systems can be categorized into four main research themes: Multiscale and Multiphase Systems Self-sustaining Biological Systems Sustainable Industrial Systems Measurement Science and Instrumentation Systems

9.2 Requirements for Graduate Program in Chemical Engineering An M.Sc. in chemical engineering is a stepping stone to a challenging, varied and exciting career. Graduates will normally need a minimum of a second-class honors degree in chemical engineering, but some universities may require a minimum of Second Class Upper (from 3.5 GPA) or a minimum of 3.0 GPA. Graduates with not-so-good grades, however, can advance to do a Post Graduate Diploma (PGD) in chemical engineering which usually lasts for just one year. Assessment will usually take the form of final examinations, coursework and a research project/report. An M.Sc. in advanced chemical engineering in some universities is more oriented toward the design and development of formulated products i.e., food and pharmaceuticals, whereas in some other universities, the master’s course covers areas such as clean technologies, energy conservation and environmental management.

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To qualify for the Ph.D. program, a student must demonstrate competence in graduate course work and demonstrate the capability to do independent research. Doctoral candidates are usually required to sit and pass a qualifying exam on chemical engineering fundamentals and practice. This is in addition to possessing an M.Eng. degree in chemical engineering with GPA of not less than 3.5 (rarely) or 4.0. Some universities admit B.Sc./B.Eng. candidates to pursue a direct and continuous three- or five-year doctoral program.

9.3 Options in Chemical Engineering Postgraduate Programs Chemical engineering postgraduate students can specialize in any of the wide-ranging options, depending on options available in the institution of choice. Degree program specialty description may also vary across the world. Generally, specific areas of specialization in a chemical engineering postgraduate program are listed in Figure 9.3.1. Chemical Engineering Postgraduate Program

Areas of Specialization

• Advanced Chemical Engineering with Biotechnology/Biochemical/ Medical/(Bio) Engineering • Engineering Management in Chemical Engineering • Advanced Materials Engineering Option • • • • • • • •

Process Systems Engineering (PSE) Option Chemical Process Engineering Oil and Gas Engineering Advanced Chemical Engineering with Polymer Engineering Advanced Chemical Engineering with Structured Product Engineering (SPE) Process Automation, Instrumentation and Control Option Process and Equipment Design Option Advanced Chemical Engineering with Information Technology and Management • Innovative and Sustainable Chemical Engineering • Catalysis, Kinetics and Reaction Engineering, and so on.

Figure 9.3.1 Areas of Specialization in Chemical Engineering Postgraduate Program.

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9.3.1 Advanced Chemical Engineering with Biotechnology/ Biochemical/Medical/(Bio) Engineering The Advanced Chemical Engineering (ACE) course allows chemical engineering graduate students to undertake advanced study in chemical engineering coupled with suitable background study in basic sciences, mathematics and computing techniques, while the specialized M.Sc. streams (Biotechnology/ Biochemical/Medical/(Bio) Engineering) give students the opportunity to explore one aspect of chemical engineering in more profundity. The Biotechnology/Biochemical/Bioengineering course provides a firm base in the science and engineering of biological processes, ranging from metabolic engineering and tissue engineering to wastewater treatment. Biochemical engineering graduate students are involved in a broad range of biologically based research including studies of bioprocess design, bioreactor scale up and optimization, membrane structure and transport, design of stable and efficient expression systems, and metabolic pathway design, and so on. Medical Engineering focuses on the applications of medical/biological sciences and engineering principles to the design, analysis, and implementation of diagnostic, therapeutic, and monitoring devices and systems for translational medicine. Some bioengineering topics include Biomaterials, Protein adsorption at surfaces, Protein engineering and gene splicing, Cell interactions with foreign materials, Drug delivery, Molecular bioengineering, etc. Generally, emphasis on this area is how to effectively translate advances in life sciences into real outcomes of benefit to all.

Figure 9.2.1 Biochemical engineers research the engineering aspects of biological systems of humans (Image Sourced: https://www.rit.edu/kgcoe/chemical/about/application-areas/, 2017).

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ACE students may be required to take up to ten or more modules, normally including up to two industrial and business studies modules.

Typical ACE modules include: • • • • • • • •

Fluid mechanics Nuclear chemical engineering Particle engineering Introduction to nuclear energy Process development Process heat transfer Environmental engineering (two modules) Reaction engineering II (two modules)

9.3.2 Engineering Management in Chemical Engineering Engineering Management is a multidisciplinary field that involves the application of engineering principles and technologies to business practices. The mission of the M.E.M. program is to develop managers who understand both the engineering and business aspects of technology. A recent study of the program reveals that M.E.M. graduates consistently perform within the top 20% of their peer group and often rise faster to leadership positions. MEM program offers graduates the opportunity to learn how to lead technology projects as well as manage teams, engineering functions, and companies. This is also a suitable program to help chemical engineering graduates who wish to become technical entrepreneurs understand the enterprise creation process. This is because the MEM degree in chemical engineering incorporates business knowledge and communication skills and adds technical knowledge necessary to lead engineering teams and execute complex projects and solutions. The MEM degree includes topics such as operations research, advanced engineering economics, mathematical modeling of engineering systems; new product development, experience design, technology strategy, lean improvement, software methodologies, multinational strategies, and the art of leadership. Course topics are designed to provide graduate students with the necessary quantitative, business, and operations knowledge necessary to succeed as innovative leaders in today’s challenging and competitive global marketplace. Postgraduate students of MEM in chemical engineering would be required to retreat to a chemical engineering department to take up thesis work upon completing core engineering management courses.

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With Master of Engineering Management degree, chemical engineering graduates: • Develop relevant soft skills including leadership, negotiation, and communication skills; • Customize the degree with a wide variety of technical electives, with the flexibility to focus on innovation management, project management, technology management, operations management, financial engineering, entrepreneurship, and so on; • Work in a start-up company as well as in a large industrial complex as business development analysts with ability to convey complex technical information to customers in business terms; • Build a business competence with core courses in management, marketing, finance, and intellectual property and business law. Graduates of a Master of Engineering Management in Chemical Engineering program find rewarding opportunities in a wide variety of positions in either oil and gas or chemical industries, including plant supervision, project management, process engineering, quality assurance, purchasing, production planning and control, systems analysis, inventory management and technical sales.

9.3.3 Advanced Materials Engineering Option A chemical engineering master’s degree in advanced materials engineering is a stand-alone qualification designed to prepare graduate students to solve problems in materials science and engineering under the exacting conditions we encounter today. The program is broad, covering many aspects of both the science of materials and engineering applications. The advanced materials engineering science option emphasizes the mastery of basic principles and methods of chemical engineering. Courses and research opportunities are available in the areas of nanotechnology, biomaterials, ceramic materials, impact damage, composite materials, electron microscopy, intermetallic alloys, laser processing of ceramics, shape memory alloys, polymers and their composites, surface, surface modification of metals and polymers, structural thin film, and super plasticity of metals, electronic and photonic materials.

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The course covers the core materials topics of metals, polymers, plastics, ceramics and composites, but also explores the progressive areas of forensic engineering and product failure investigation, new and smart materials and use of materials in the generation of energy. Chemical engineering graduate students will gain exposure to the latest trends in design, materials, manufacturing processes, testing and advanced applications by taking full advantage of our modern technology and computing facilities.

Core modules: • Materials Modeling • Materials Characterization • Creativity in research (a general course that includes transferable skills, problem solving and attendance at scientific seminars)

Current research includes developing novel surface engineering processes and materials (such as fullerene-like coating materials); nanomaterials and nano characterization techniques; energy-based methods for performance modeling; and novel materials for intensified processes. The measurement and modeling of the mechanical response of materials at high-spatial resolution, particularly in microelectronic and optical devices, is also a specialty area that requires interdisciplinary expertise. Another important research focus is the materials requirements for the sustainable development and use of key resources, in particular water and energy. Significant research will be on generation of energy from novel sources, low carbon and renewable technologies and the clean-up of effluent and wastewater. These areas of research include: cold plasma gasification; fuel cells and energy systems; gasification; bio-fuel cells or fuel cell electrocatalysis and systems; nanostructured polymer composites for pollution control; bio-diesel production; gas and water treatment; sustainable and environmental electrochemical systems; Polymer rheology and tribology, Surface science; nanometer scale Polymers and photochemical processes, microelectromechanical systems (MEMS) and electrochemical synthesis, and so on.

9.3.4 Process Systems Engineering (PSE) Option Process Systems Engineering (PSE) is an academic and technological field involving methodologies for chemical engineering decisions. The

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methodologies must be responsible for indicating how to plan, how to design, how to operate, how to control any kind of unit operation, chemical, biochemical and other production processes. Hence, PSE is all about the systematic and model-based solution of systems problems in chemical engineering (Ponton, 1995). Systems engineering addresses all practical aspects of a multidisciplinary structured development process that proceeds from concept to realization to operation. The Process Systems Engineering (PSE) option allows graduate chemical engineering students to develop an understanding of the mathematics relevant to systems engineering and gives an advanced treatment of control theory, modeling, simulation, data analysis, monitoring of complex systems, control and maintenance of efficient process systems and design and management techniques, along with their application to the field of process systems engineering. Applications include chemical, biological, and environmental systems spanning length scales from the molecular and industrial scales to the global scale. The research efforts are underpinned by the study of the underlying theory, the development of novel analytical and computational tools and algorithms, and the applications via computer simulations to practically relevant systems. The M.Sc. in Process Systems Engineering has been developed to equip graduates and practicing chemical engineers with an in-depth understanding of the fundamental issues of process systems within the process chemical industries. This specialty provides technical knowledge and skills required for achieving the best management, design, optimization, control and maintenance of efficient process systems.

Typical PSE modules include: Advanced process optimization I Advanced process optimization II Dynamic behavior of process systems Dynamical systems in chemical engineering

Figure 9.2.3 Typical PSE Modules.

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9.3.5 Chemical Process Engineering Multinational pharmaceutical corporations and chemical companies employ chemical engineers with masters or doctorate degrees as chemical process engineers in various departments. High-level senior process engineer positions almost always require candidates to have a Ph.D. The aim of this master’s degree is to prepare students to carry out research or professional tasks in high-level activities. This qualification enables specialists to conceive, design, model and analyze industrial processes typical of the chemical or pharmaceutical industries or any other area of chemical engineering. The courses offered include advanced thermodynamics, the design of equipment and installations, and the simulation and optimization of processes, etc. Process engineering often involves close collaboration of chemical engineers and scientists from a variety of disciplines. The recent advances in process design and the increase in awareness of economic, safety and environmental issues have reinforced the importance of this type of collaboration. As well as covering core chemical engineering subjects, the M.Sc. program provides students with a wide and diverse range of options such as law for managers, project management and new venture business. Students also have a choice between taking either a research or an advanced design project. The research project on the other hand may be selected from a range of different topics offered. Safety and loss prevention and sustainability are the key mandatory part of the M.Sc. program. It is covered both in the form of lectures taught by experts from industry as well as forming an integral part of the Advanced Design project.

9.3.6 Oil and Gas Engineering A postgraduate degree in oil and gas engineering is another option for graduate chemical engineers. The oil and gas field operations has grown as has the demand for well-qualified chemical engineers who are conversant with the latest technology. This study often includes project management. This graduate program provides chemical engineering graduate students with advanced knowledge in the relevant underpinning sciences of fluid mechanics and thermodynamics together with knowledge and skills required in the oil and gas production and processing industries. Specialist research activities in a wide range of chemical engineering topics are undertaken which include process simulation, energy utilization,

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carbon capture and sequestration, oil and gas engineering, heat transfer and fluid dynamics. A postgraduate degree in Oil and gas engineering generally emphasizes oil and gas technology, its application, uses, refinements and so on. To provide these skills, the programme consists of fundamental courses in the essential sciences, • • • • • • •

Thermodynamics Fluid mechanics Courses in the relevant engineering subjects, Production technology, Reservoir engineering, Pipeline engineering, and Process engineering, complemented by a course on Petroleum economics and planning.

9.3.7 Advanced Chemical Engineering with Polymer Engineering Plastics are present in practically every facet of life and play a large part in shaping the look and feel of today’s world. This course is unique on its own. It takes chemical engineers’ solid foundation and adds polymer engineering and a strong emphasis on project management skills. Graduate students will acquire strong polymer engineering skills which will enhance their employability prospect in the world of plastics engineering. Research programs in the Advanced Chemical Engineering with Polymer Engineering option include structural, spanning synthesis, functional, and biological materials, characterization, processing, modeling activities, with strong links to academic, government, and industrial research centers. Areas include plasma processing (e.g., nanofluids, carbon nanotubes, advanced coatings) and polymeric or “soft” materials research (e.g., self-assembling or structured materials, liquid crystals, complex fluids, colloids and soft composites and novel polymerization methods). Applications of the research are targeted toward the development of next-generation high-density storage media, electronic devices, functional coatings, composite fluids and “smart” materials, to name but a few.

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9.3.8 Advanced Chemical Engineering with Structured Product Engineering (SPE) The Structured Product Engineering (SPE) option offers graduate chemical engineering students an understanding of the physicochemical phenomena that affect the behavior of structured products, such as pastes, creams, and other consumer products. It also offers an introduction to experimental and modeling techniques that allow the study of such systems. This option is ideal for graduate chemical engineering students interested in gaining in-depth study of the behavior of structured products and a better view of the interplay between materials, processing and properties. Consumer chemical process industries are in need of chemical engineers who can design and develop formulated or structured products, in addition to having the knowledge of biotechnology and environmental perspectives. Consumer products come with very different microstructure. SPE deals with the design of a variety of new products for the electronic industry, pharmaceutical industry and other major companies that manufacture consumer goods. Products can be characterized by a microstructure in the 0.1-100 um range. Alteration of the microstructure of a product can give rise to different functionality and customer appeal. The SPE concept is another way of putting products rather than the process into focus. The program aims to: • Foster the acquisition and implementation of broad research and analytical skills both general and that related to Structured Product Engineering; • Develop an understanding of how the knowledge gained may be applied in practice in an economic and environmentally friendly fashion. SPE students take 10 modules, of which four must be in the structured product engineering module list, and up to two can be from the industrial and business studies modules. Typical SPE modules include: • • • •

Colloid and interface science Formulation engineering and technology Polymers and polymerisation processes Product characterisation

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9.3.9 Process Automation, Instrumentation and Control Option It is inconceivable nowadays that anybody would consider building a new plant, upgrading an existing plant or designing a new process without installing comprehensive instrumentation and control systems. The development of automation, instrumentation and control systems can be more complex than the design of the plant itself. Chemical engineering graduates who wish to learn how to enhance processes with Instrumentation and control computer-based engineering systems would find this option interesting. With this course the graduate chemical engineer will learn how to design, install, manage and maintain equipment which is used to monitor and control engineering systems, machinery and processes. Technologies for controlling a range of manufacturing and industrial processes such as programmable logic controllers PLC, and supervisory control and data acquisition SCADA are taught. A chemical engineering graduate upon completing a master’s degree in this option will acquire the skill necessary to work to ensure that systems and processes operate effectively, efficiently and safely. Such skill will enable the graduate to be employed by the companies who manufacture and supply the equipment, or for the companies who use it. Opportunities abound in various areas such as nuclear research, food, mining, paper, space, chemical, power, oil and gas, manufacturing, construction, utilities, defense, security, equipment vendor, medical, and other industries. Skills to be acquired include three-phase electrical motor control, temperature, pressure, level, and flow devices, variable frequency drives (VFD’s), sensors, programmable logic controllers (PLC’s), robotics, PID loops, human machine interfaces (HMI) and others. See more at http:// www.isu.edu/estec/automation.php.

Figure 9.2.4 A Process Instrumentation and Automation Engineer (Picture Sourced: http:// www.imperial.ac.uk/study/pg/courses/chemical-engineering/process-automation/, 2014).

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9.3.10

329

Process and Equipment Design Option

Chemical engineering graduate programs in this option teach skills related to the design of equipment and processes for chemical manufacturing, testing methods of products and production. The Process and Equipment Design program is an advanced level traineeship that trains and educates M.Sc. graduates to become certified designers, capable of designing “fit for purpose” and “first of its kind” products, processes and equipment. The objective is for students to acquire the process and equipment design skills. Emphasis lies on the interdisciplinary area of the design. It aspires to actively look beyond the confines of the core discipline and to recognize the challenges and restrictions imposed by product chain management, environment, time and money. By working on industrially relevant design cases during the course, acquired knowledge can be integrated into work. The course enhances the interactions between engineering disciplines (chemical, mechanical, control) and improves the understanding of economic and management aspects of plant design and operation. There are three Dutch technical universities, Delft University of Technology, Eindhoven University of Technology and Twente University that offer two-year post-M.Sc. PDEng (Professional Doctorate in Engineering) design programs.

9.3.11

Advanced Chemical Engineering with Information Technology and Management

The advanced chemical engineering with information technology and management program focuses on advancements of information technology and business management skills in the development of chemical processes. It builds on the chemical engineering field’s established strengths in computer modeling, process systems engineering, numerical modeling, computational fluid dynamics, finite element modeling, process control and development of software for process technologies. The program aims to: • Provide in-depth understanding of the IT skills required for advanced chemical processes; • Raise students’ awareness of the basic concepts of management techniques applicable to running a production company.

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9.3.12

Innovative and Sustainable Chemical Engineering

Innovation means discovery plus development. Chemical engineering is consequential to sustainability. Sustainability study involves finding ways to satisfy both the consumer requirements for specific end-use properties and characteristics of products and the social and environmental constraints of industrial-scale processes. Innovative and sustainability chemical engineering program focuses on: • Applying sustainability principles and techniques to materials and process engineering; • Design and evaluation of sustainable and innovative processes and systems; • Developing new sustainable chemical products and processes; • Identifying environmental and sustainability limitations of processes; • Developing processes for producing chemicals and energy from renewable materials.

9.3.13

Catalysis, Kinetics & Reaction Engineering

The catalysis research in the graduate program focuses on fundamental characterization of supported metal complexes and clusters. The field involves precise synthesis from organometallic precursors on high-area porous supports, including metal oxides and zeolites. Spectroscopy of functioning catalysts to determine structures of the catalytic species are emphasized. The techniques include X-ray absorption, IR, and NMR spectroscopy, and high-resolution transmission electron microscopy. The catalysts can include structurally well-defined supports, including zeolites and nanostructured oxides (such as ceria based materials). Zeolites are applied in the catalytic cracking of hydrocarbon in petroleum refinery—a process unit known as fluid catalytic cracking unit (FCCU).

9.4

Chemical Engineering Research Needs and Opportunities

Emerging New Fuels As new fuels derived from oil shale, coal, oil sands, and biomass feedstock emerge as replacements or complements for light, sweet crude oil, both

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uncertainties and strategic opportunities arise for chemical engineers. Chemical engineers must find ways of efficiently exploiting fuel from these sources. Consequently, new ways of designing, implementing, and producing fuel from these sources may be in the offing. Alternative Energy to Fossil Fuel The efficiency of alternative energy sources, such as solar energy, need to be improved. Opportunity for further research to realize this abounds for chemical engineers. New materials to efficiently absorb sunlight, new techniques to harness the full spectrum of wavelengths in solar radiation, and new approaches based on nanostructured architectures are opportunities for changing ways of generating solar energy. The technological advances in single-crystal solar cells, in addition to its commercialization, demonstrate the promise and practicality of photovoltaics. Sunlight is converted to electricity via photovoltaic solar cells. Also, novel approaches exploiting thin films, dye sensitization, organic semiconductors, and quantum dots offer fascinating new opportunities for cheaper, more efficient, longer-lasting systems. Other leading developmental areas of growth in the energy sub-sector research and development into biomass gas and liquid fuels production include: harnessing various feedstock options, integrating eco-efficiency and green energy in transportation and power generation; incorporating cogeneration facilities for electric power generation; development of highly efficient silicon absorbers and high-capacity storage cells for solar panels; controls of obstacles to the widespread use of grid-connected small wind energy conversion systems, (SWECS), and countrywide integrated pipeline design for uninterrupted natural gas supplies to power generating stations. Molecular Biology In addition, with advances in molecular biology and medicine potential areas for contributions to human health include the diagnostic tests, design and manufacture of artificial organs, and therapeutic drugs. Another area includes chemotherapeutic engineering, which is defined as an engineering discipline that applies and further develops chemical engineering principles, techniques and devices for chemotherapy of cancer and other diseases. Chemotherapy is one of the most important treatments currently available for cancer and cardiovascular diseases which are a leading cause of deaths. The present status of chemotherapy is far from being suitable. Chemotherapeutic engineering is emerging to help solve the problems in

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chemotherapy and to eventually develop an ideal way to conduct chemotherapy with the best efficacy and the least side effects. Agriculture Furthermore, the manufacture of veterinary pharmaceuticals and the scaling up of plant cell-culture techniques will require increasing applications for chemical engineering principles. Hence, in the agricultural sector, opportunities include using genetically engineered systems for the synthesis of chemicals and the biological treatment of waste. The intellectual frontiers that chemical engineers should pursue in this area include modeling of fundamental biological interactions, expanding the scope of process engineering into biological systems, investigating surface and interfacial phenomena important to engineering design-living systems, and conducting engineering analysis of whole-organ or whole-body systems. However, the commercialization of developments in biotechnology will require a new breed of chemical engineer, one with a solid foundation in the life sciences as well as in process engineering principles. Other Areas Chemical engineers will conceive and thoroughly solve problems on a continuum of scales ranging from microscale to macroscale. Thus, chemical engineers of the future will be integrating a wider range of scales than any other branch of engineering and this will result in more research opportunities. Process System Engineering (PSE) PSE is an academic and technological field related to methodologies for chemical engineering decisions. PSE is young, just about 35 years old, and its progress is closely tied with developments in computer technology. It is formed for the understanding and development of systematic procedures for the design and operation of chemical process systems, ranging from microsystems to industrial-scale processes. Figure 9.3.1 can be used to expand our understanding of PSE by making use of the concept of the “chemical supply chain”. The starting point of the supply chain is the set of chemicals that industry must synthesize and characterize at the molecular level. This is followed by further steps where these molecules are aggregated into clusters, particles and films, then as single and multiphase systems that finally take the form of macroscopic mixtures. Transitioning from chemistry to engineering, the next step becomes design and analysis of the production units, which are integrated

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enterprise Site Plants Process units

Molecule cluster

Particles & thin films

Single and multiphase systems

molecules Small (Chemistry)

Intermediate (Engineering)

Large (Business Management)

Figure 9.3.1 Chemical Supply Chain.

into a chemical process that in turn becomes part of a site with multiple processes. The site finally is part of the commercial enterprise driven by business considerations.

Figure 9.3.2 Process Systems Engineering Facility (Image sourced: http://www.cranfield. ac.uk/courses/masters/process-systems-engineering.html, 2014).

Thus, PSE in a broader sense can be defined as: engineering concerned with the improvement of decision-making processes in chemical process industries for the creation and operation of the chemical supply chain. It deals with the discovery, design, manufacture and distribution of chemical products in the context of many conflicting goals.

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This definition by Grossmann and Westerberg (2000) [144], which is based on the concept of the chemical supply chain described above, ties fundamental scientific discoveries at the molecular or microscopic level with strategies and logistics for manufacturing. This definition also directly ties to industrial needs from R&D to product distribution. The major goal is to improve all these activities by improved and systematic decision making, which has both theoretical and practical implications. This therefore opens opportunities for chemical engineering researches. Product Engineering Chemical Engineering is shifting from being primarily processing to simultaneous product development integrated with additional process to make the products available. Chemical engineering expertise in this field is constantly growing due to the following reasons: • About 60% of all products, which major chemical manufacturing companies now sell to its customers, are polymeric, crystalline or amorphous solids. To meet desired quality standards, these products will have a clearly defined physical size and shape. These physical features also apply to emulsified and paste-like products; • A more complex in terms of molecular structures but highly specialized materials is increasingly required for novel developments.

The main difference between process design and product design is the addition of steps before the design of the process. These steps have to do with the identification of customer need, generation of smart ideas to meet the need and selection among the generated ideas, which require entrepreneurial skills. Hence, to move toward the molecular level, commonly applied process design will be expanded to include product design, with specific emphasis on design of new molecules. The main difference in this case will be the need to develop predictive capabilities for properties of compounds and mixtures of compounds, ranging from fluids to structured materials, and the systematic generation of alternatives so as to apply developed methodologies for structural decisions in process design. Product design

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involves an understanding of the structure and property relationship at the molecular, microscopic or nano level. By controlling the microstructure formation, product quality can be determined, thus obtaining the desired end-use properties of a product. Process Intensification/Increasing Efficiency Another major current trend in Chemical Engineering is Process Intensification (PI). PI was developed based on the need to protect the environment and due to economic factors. Process intensification (PI) is all about developing compact, energy-efficient, safe and environmentally friendly sustainable processes. Stankiewicz and Moulijn (2000) [155] explain that Process intensification concerns only engineering methods and equipment. They argue that this idea consists of the development of novel apparatuses and techniques that can be expected to bring significant improvements in manufacturing and processing, when compared to those being used today. If a single piece of equipment can have multivariant functions and be very much smaller in size, without compromising volume of yield, the process invariably becomes more economical in terms of operation as well as space. Enhanced energy efficiency, waste reduction and waste treatment are still hard to achieve; this trend, as a result, is likely to continue. A substantial decrease in equipment-size/production-capacity ratio, energy consumption, or waste production that eventually lead to cheaper sustainable technologies is expected from PI application—a means of integrating microsystems or novel unit operations. Making a compact process requires a two-divided approach—firstly, using physical principles to make equipment more compact and or multifunctional, and secondly, selecting or developing chemical routes for more efficient production. A combination of both is the trend for sustainability. Centrifugal mass transfer units, reactive distillation columns, and microreactors are some of the examples of equipment-oriented process intensification. The extractive reaction process, for example, involves a single unit that combines reaction and separation operations which leads to reduction in the size of the entire process facility due to reduction in the number of equipment. This in turn, will lead to reduced cost and significant energy saving or recovery—a case of sustainability. Research in finding new ways of production, development of multifunctional reactors, microengineering and microtechnology will intensify. Already, engineers are designing and manufacturing miniature/modular plants that contain microreactors, microheat exchangers, microanalyzers, etc. If this mini plant is coupled

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with a mini multifunctional reactor, a more mini plant can be developed. A multifunctional reactor can be coupled with exothermic and endothermic reactions. That is by using heat integration for more efficient energy use in the process. The coupled reaction can be carried out in a shell and tube exchanger design. This will lead to a compact design. These areas are expected to become a major focus of chemical engineering R&D efforts because of the indubitable economic prospects. Catalysts, Surface Science, Nanoscience/technology Chemical engineers are developing nanoprobes, nanomaterials, nanotubes, nano catalysts and nanostructures for a variety of applications in composite solid rocket propellants, bio diesel production, fuel cell, in medicine, energy storage, in dye, in electronics and other areas. Engineers are also applying advanced surface science methods in studying the mechanism and kinetics of chemical reactions at surfaces and interfaces. Other areas of focus include finding ways of manipulating materials at nanoscale to fit properties and performance (nanostructure synthesis). Hence, it will be possible to to address technological challenges in a variety of fields such as the surface science, separations and catalysis. The advanced materials structures created can be used to fabricate nanometer thick polymeric membranes for advanced filtration applications, for example. Similarly, advances in surface science techniques help in the development of next-generation nano catalysts. The development of an effective catalyst in both composition and functionality is key to a successful industrial catalytic process. These catalysts exhibit high activities and can show high stability and selectivity characteristic. Highly selective catalysts can help reduce the energy requirement for product separation and waste disposal processes. Given the foregoing benefits of the field, catalysts, surfaces and nanomaterials are therefore more likely to continue to draw more research effort from chemical engineers in future.

References 1. Slin’ko, M.G., Evolution, Goals, and Objectives of Chemical Engineering. Theor. Found. Chem. Eng., 37, 421, 2003. 2. Buecker, B., Clarifying the Role of the Lead Process Engineer. Chem. Eng., 3, 44–49, 2010. 3. Jenkins, S., Facts at your Fingertips. Chem. Eng., 9, 26, 2010. 4. Types of Process Engineering Services, Process Engineering Associates, LLC, www.processengr.com. 2012. 5. Rosenberg, N., Chemical Engineering as a General Purpose Technology, in: General Purpose Technologies and Economic Growth, H. Eihanam (Ed.), pp. 167–192, MIT Press, Cambridge, MA, 1998. 6. Landau, R., Education: Moving from chemistry to chemical engineering and beyond. Chem. Eng. Prog., 93, 1, 52–65, 1997. 7. Brock, W.H., History of Chemistry, Norton, New York, 1992. 8. Yukio, Y., Suguru, N., Hiroshi, K., Key Role of Chemical Engineering for Technology Innovation, www.tandfonline.com/doi/full/10, 2008. 9. Lagace, J., E&C Projects, Clarifying the Role of the Lead Process Engineer. Chem. Eng., 3, 44–50, 2011. 10. Appl, M., The Haber-Bosch process and the development of chemical engineering, in: A Century of Chemical Engineering, W.F. Furter (Ed.), pp. 29–54, Plenum, New York, 1982. 11. Why Chemical Engineering Emerged in America Instead of Germany, 2015. www.creatingtechnology.org/chE.htm. 12. History of Chemical Engineering, www.pafko.com/history, 2014. 13. Reynolds, T.S., 75 Years of Progress: A History of the American Institute of Chemical Engineers, AIChE Press, NY, 1983. 14. What’s That Stuff, www.pubs.acs.org/cen/whatstuff/stuff.htm, 2017. 15. Robert, P., Chemical Technology: The Past 100 years. Chem. & Eng. News, 54, 15, 190, 2003, April 1976. 16. Anyaoku, O., Challenge of Chemical Engineering in Leading Development of National Energy Framework. NSChE Proceed., 37, 19–29, 2007. 17. Hougen, O.A., Seven Decades of Chemical Engineering. Chem. Eng. Prog., 73, 1, 89–104, 1977. 18. Pigford, R.L., Chemical technology: The past 100 years. Chem. Eng. News, 190–203, 1976. Centennial issue. Uche Nnaji (ed.) Introduction to Chemical Engineering: For Chemical Engineers and Students, (337–344) © 2019 Scrivener Publishing LLC

337

338

References

19. Scriven, L.E., On the emergence and evolution of chemical engineering, in: Perspectives in Chemical Engineering, C.K. Colton (Ed.), pp. 3–40, Academic Press, Boston, 1991. 20. Chemical Engineers in Action, www.chemicalengineering.org, 2006. 21. Jefferson, E.D., The emergence of chemical engineering as a multidiscipline. Chem. Eng. Prog., 84, 1, 21–3, 1988. 22. The Early History of Chemical Engineering – A Reassessment, 2014. https:// www.scribd.com/document/209267660/The-Early-History-of-ChemicalEngineering-A-Reassessment. 23. Ponton, J., Process systems engineering: Halfway through the first century. Chem. Eng. Sci., 50, 4045–4059, 1995. 24. Ondrey, G., Food from Algae. Chem. Eng., 9, 2010. https://www.chemeng online.com/food-from-algae/. 25. Scriven, L.E., The role of past, current, and future technologies in chemical engineering. Chem. Eng. Prog., 83, 12, 65–9, 1987. 26. Wintermantel, K., Process and Product Engineering – Achievements, Present and Future Challenges. Chem. Eng. Sci., 54, 1601–1602, 1999. 27. Chemical Engineering: Introduction, http://career.webindia123.com/career/ options/engineering/chemical/intro.htm, 2017. 28. Rebecca, K.T., Chemical Engineering Thermodynamics: Transforming “Thermo” Lectures into a “Dynamic” Experience, Department of Chemical Engineering, Mississippi State University, Mississippi, MS 39762, 2017. 29. Schools in the USA.com website: Refinery Engineer, http://www.schools intheusa.com/careerprofiles_details.cfm?carid=153, 2016. 30. Perry, R and Green, D., Perry’s Chemical Engineer’s Handbook, pp. 22–38, McGraw-Hill Companies, Inc., New York, 1999. 31. Foam fractionation, 2016. https://en.wikipedia.org/wiki/Foam_fractionation. 32. Rohani, S., Application of the Crystallization Process in the Pharmaceutical Industry. Front. Chem. Eng. China, 4, 1, 2–9, 2010. 33. Alford, J. and Edgar T., Preparing Chemical Engineering Students for Industry. Chem. Eng. Prog., 113, 11, pp. 25–28, AIChE, November, USA, 2017. 34. Baytiyeh, H. and Naja M., AC 2011–1421: Challenges Facing Graduating Engineers in their Transition from College to Career, pp. 22.317.1–22.317.10, American Society for Engineering Education, Beirut, 2011. 35. Molzahn, M. and Wittstock K., Chemical Engineers for the 21st Century – Challenges for University Education. Chem. Eng. Tech., 25, 3, WILEY-VCH Verlag GmbH, Weinheim, pp. 231–235, 2002. 36. The Institution of Chemical Engineers, www.icheme.org, 2019. 37. The American Institute of Chemical Engineers, www. aiche.org, 2019. 38. Renewable Energy in Germany, www.wikipedia.org, 2016. 39. Sanjeev, K.G. and Others, Recommendations of the National Symposium on Chemical Engineering – The Journey Ahead, Organized by Department of Chemical Engineering Indian Institute of Science Bangalore 560 012, 2005.

References 339 40. Beer, J., Coal tar dye manufacture and the origin of modern industrial research laboratory. Isis, 49, part 2 (156), 123–31, 1958. 41. SRI Consulting. Chem. Eng., 3, 19, 2011. 42. Wispelwey, J., Drug delivery and chemical/biological engineering. Chem. Eng. Prog., 3, 18, 2013. 43. American Society of Technion, Novel Ceramic Foam Is Safe and Effective, https://www.sciencedaily.com/releases/2001/05/010518082028.htm, 2001. 44. Perry, R. and Green, D., Perry’s Chemical Engineer’s Handbook, pp. 25–14, McGraw-Hill Companies, Inc, New York, 1999. 45. Mendez M., The Role of Chemical Engineers in Green Engineering. Chem. Eng., Dec. 2007. https://www.chemengonline.com/feature-report-the-role-ofchemical-engineers-in-green-engineering/?printmode=1, 2019. 46. Furter, W., History of Chemical Engineering, American Chemical Society, Washington, D.C, 1980. 47. Coal, https://en.wikipedia.org/wiki/Coal, 2016. 48. Nanoscale Electronics, Photonics and Materials Processing, http://www. cheme.cornell.edu/research/area.cfm?area = 190, 2016. 49. Pharmaceutical CGMPs for the 21st Century – A Risk-Based Approach, Department of Health and Human Services, U.S. Food and Drug Administration, 2004. 50. Guidance for Industry PAT — A Framework for Innovative Pharmaceutical Development, Manufacturing, and Quality Assurance, Department of Health and Human Services, U.S. Food and Drug Administration, 2004. 51. Antimicrobial Additives for Food Packaging Films, Tu Wien Institute of Chemical Engineering, https://www.vt.tuwien.ac.at/home/, 2016. 52. Byron, B., A Century of Transport Phenomena: Was a Transport Phenomena Course in Chemical Engineering Curricula Inevitable? AIChE Annual Meeting, 2008. 53. U.S. Coal Supply and Demand: 2010 Year in Review, http://www.eia.gov/ coal/review/coal_consumption.cfm, 2016. 54. Colton, C.K., Perspectives in Chemical Engineering, Academic, Boston, 1991. 55. Elder, A.I., The history of penicillin production. Chemical Engineering Progress Symposium series, 66, No. 100, pp. 1533–1697, New York, 2013. 56. Eyring, H., Physical chemical: The past 100 years. Chem. Eng. News, 4, 88–109, 1976. 57. Hobby, G.L., Penicillin: Meeting the Challenge, Yale University Press, New Haven, 1985. 58. Servos, J.W., The industrial relations of science: Chemical engineering at MIT, 1900-1939. ISIS, 71, 531–49, 1980. 59. ACS and AIChE, Technology Vision 2020, the US Chemical Industry, 2013. www.che,.purdue.edu/v2020. 60. Mascone, C.F., Engineering the next millennium. Chem. Eng. Prog., 95, 10, 102–13, 1999.

340

References

61. National Research Council, Frontiers in Chemical Engineering, National Academy Press, Washington D.C, 1988. 62. Hounshell, D. and Smith, J., Science and Corporate Strategy: DuPont R&D 1902-1980, Cambridge University Press, New York, 1988. 63. Si-Shen, F. and Shu, C., Chemotherapeutic Engineering: Application and Further Development of Chemical Engineering Principles for Chemotherapy of Cancer and other Diseases, a Division of Bioengineering, Faculty of Engineering, National University of Singapore, 2003. 64. Homburg, E., The emergence of research laboratories in the dyestuffs industry, 1870-1900. Br. J. History Sci., 25, 91–111, 1992. 65. Clive, L.D. et al., Engineering Design Thinking, Teaching, and Learning. J. Eng. Educ., 1, 103–114, 2005. 66. Mizrahi, J., Developing an Industrial Chemical Process an Integrated Approach, pp. 15–17, CRC Press, New York, 2002. 67. Mody, D. and Strong, D., An Overview of Chemical Process Design Engineering, in: Proceedings of the Canadian Design Engineering Network (CDEN) Conference, p. 325, Toronto, Canada, 2006. 68. Segar, B.G., and others, Rapid Process Design, www.aiche.org/CEP, 2006. 69. Silla, H., Chemical process engineering: Design and economics, Taylor & Francis Inc., Bosa Roca, USA, 2003. 70. Crawley, F.K., Safety and Loss Prevention/Safety Engineering, pp. 32–64, University of Strathclyde, Glasgow, 2014. 71. Moran, S., An Applied Guide for Process and Plant Design, Elsevier Inc., UK, 2015. 72. Gertenbach, D. and Cooper, B., Scaleup Issues from Bench to Pilot. Paper 509f presented at the AICHE National Meeting, Nashville, TN, Nov. 2009. 73. The Pilot, https://en.wikipedia.org/wiki/Pilot_plant, 2016. 74. Elshout, R., and Garcia, D., Revamps: Strategies for A Smooth Turnaround. Chem. Eng., 7, 34–39, 2009. 75. LePree, J., Separation: More, More, More. Chem. Eng., 7, 20–24, 2009. 76. Project Management Guidelines, Shell International Exploration and Production B.V., pp. 13, 56–59, 67–70, 174, The Hague, Western Netherlands, 1996. 77. Production Engineering, http://en.wikipedia.org/wiki/Production_engineering, 2017. 78. Richard, A.T. and Joseph, A.S., Chemical Process Equipment Design, Prentice Hall, New Jersey, pp. 200–300, 2017. 79. Chemical engineering, https://en.wikipedia.org/wiki/Chemical_engineering, 2017. 80. Chemical Engineering Progress, www.aiche.org/CEP, 2014. 81. Process Control, http://en.wikipedia.org/wiki/Process_control, 2017. 82. Mathew, W.O. and Sherry, A.F., NC States Engineering Entrepreneurs Program in the Context of US Entrepreneurship Programs, Clemson University, Guili Zhary, University of Florida. Education that Works: The NCIIA 8th Annual Meeting, March 18-20, 2004.

References 341 83. Devold, H., Oil and Gas Production Handbook – An Introduction to Oil and Gas Production, p. 86, ABB Oil and Gas, Oslo, 2009. 84. William, R.W., Chemical engineering design data, information and advice, http://people.clarkson.edu/~wwilcox/Design/refs.htm, 2008. 85. Process Equipment Associates, LLC, Edible Oil Hydrogenation System Detail Process Design and Startup, http://www.processengr.com/case_summaries/ food/food_edible_oil_hydrogdesign.html, 2018. 86. Viviane, Y., Design in Chemical Engineering: What are the Perspectives?, McGill University, Montreal, Canada, 2018. 87. Richard, T. and Others, Analysis, Synthesis, and Design of Chemical Processes, Third Edition, pp. 15–15, Pearson Education, Inc., Prentice Hall, 2009. 88. Hazard and Operability Study, http://en.wikipedia.org/wiki/Hazard_and_ operability_study, 2017. 89. Roles and Responsibilities of Plant Commissioning, Hydrocarbon Introduction and Acceptance Test Run, https://www.scribd.com/document/111412581/ Roles-and-Responsibilities-of-Plant-Commissioning-Rev-3, 2017. 90. Saipem S.a. Process Technical Instruction Doc. No.: IT P120, 2007. 91. Gas/Liquid Separators – Type Selection and Design Rules, Shell Global Solutions International B.V., DEP 31.22.05.11-Gen, p. 88, The Netherlands, 2007. 92. Svecek, W. and Monnery, D., Design Two-phase Separator Within the Right Limits. Chem. Eng. Prog., 10, 53–60, 1993. 93. IPS Engineering Standard for Process Requirement of Vessel, Reactors and Separators, 32, 1999, http://det-mop.ir/ips/pr/e-pr-850.pdf., 2018. 94. Mukherjee, S., Pressure-Relief System design. Chem. Eng., 11, 40–45, 2008. 95. Perry, R. and Green, D., Perry’s Chemical Engineer’s Handbook, pp. 6-50–6-51, McGraw-Hill Companies, Inc, New York, 1999. 96. Peters, M. and Timmerhaus, K., Plant Design and Economics for Chemical Engineers, pp. 150–177, McGraw-Hill, Inc., Singapore, 1991. 97. Build a career in oil and Gas, http://www.careersinoilandgas.com/buildyour-career, 2014. 98. Project Engineer, http://en.wikipedia.org/wiki/Project_engineer, 2016. 99. What is Process Safety Engineering?, http://www.scribd.com/doc/2554288/ What-is-Process-Safety-Engineering, 2018. 100. Saipem Energy International, Oil and Gas Plants Overview Instrumentation – Automation – Telecommunication Engineer Training Program, Port Harcourt, 2006. 101. Felder, R. and Rousseau, W., Elementary Principles of Chemical Processes, 5th Edition, pp. 33–36, John Wiley & Sons, USA, 2005. 102. Markus, H. and Bernhard, W., Dynamic Project and Workflow Management for Design Processes in Chemical Engineering. Comput. Aided Chem. Eng., 15, 208–213, 2003. 103. Ponder the Process Design Basis, http://www.chemicalprocessing.com/articles/2014/ponder-the-process-design-basis/, 2016.

342

References

104. Biofuels Commercialization, Scaling up step by step, http://www.zeton.com/ site/pdf_articles/Zeton_Scaling_Up.pdf, 2016. 105. Rest Easy With a Good BEDD, http://www.chemicalprocessing.com/ articles/2014/rest-easy-with-a-good-bedd/, 2016. 106. Center for Chemical Process Safety, Guidelines for Hazard Evaluation Procedures, 3rd ed., John Wiley & Sons, New Jersey, 2008. 107. Melhem, G. and Stickles, R., Risk-Based Process Safety Design, ioMosaic Corporation, New Hampshire, USA, 2002. 108. Hendershot, D., Inherently Safer Design – An Overview of Key Elements, Professional Safety, Professional Safety, pp. 48–52, Northwest Highway, 2011. 109. Sanders, R., Chemical Process Safety – Learning from Case Histories, p. 164, Butterworth-Heinemann, Oxford, 1999. 110. Occupational Safety and Health Administration: Process Safety Management, 2019. https://www.osha.gov/Publications/osha3132.html. 111. Jeremy, C., Lifting the Lid on Process Risk, 2008. www.tcetoday.com. 112. Center for Chemical Process Safety, Guidelines for Engineering Design for Process Safety, John Wiley & Sons, New Jersey, 2012. 113. Kong, D., Gas Explosion Hazard: Prevention and Protection, in: Encyclopedia of Chemical Processing, S. Lee (Ed.), pp. 1109–1118, Taylor & Francis, New York, 2006. 114. Center for Chemical Process Safety, Guidelines for Design Solutions for Process Equipment Failures, pp. 5–30, American Institute of Chemical Engineers, New York, 1998. 115. Haight, J., Loss Prevention in Chemical Processing, in: Encyclopedia of Chemical Processing, S. Lee (Ed.), pp. 1487–1488, Taylor & Francis, New York, 2006. 116. Ben-Eli, M., Sustainability: Definition and Five Core Principles, http://www. sustainabilitylabs.org/assets/img/SL5CorePrinciples.pdf, 2015. 117. Hatziavramidis, D., New Paradigms in Chemical Engineering: Health, Climate Change and Energy, and Product Design. Ind. Eng. Chem. Res., 50, 473–481, 2011. 118. Vargas, C. and Schlumberger, H., Continuous Improvement Strategy to Stimulate Sustainability and Enhance Environmental Management, SPE, Abu Dhabi International Petroleum Exhibition and Conference, UAE, 2015. 119. Thompson, A., Hallstedt, S., Isaksson, O., Introductory Approach for Sustainability Integration in Conceptual Design, International Design Conference, Dubrovnik - Croatia, 2012. 120. Clark, G. and others, Design for Sustainability: Current Trends in Sustainable Product Design and Development, www.mdpi.com/journal/sustainability, 2009. 121. Sadhukhan, J., Siew Ng, K., Hernandez, E., Biorefineries and Chemical Processes: Design, Integration and Sustainability Analysis, 1st ed., pp. 93–123, John Wiley & Sons, USA, 2014.

References 343 122. Mosavi, A., Optimization and Decision Making in Chemical Engineering Problems. Global J. Res. Eng., 10, 3, 9–13, 2010. 123. Ghenai, C., Sustainable Engineering and Eco Design, http://www.intechopen. com/books/sustainable-development-energyengineering-and-technologiesmanufacturing-and-environment/sustainable-engineering-and-ecodesign-, 2012. 124. Li, S., Mirlekar, G., Ruiz-Mercado, G.J., Lima, F.V., Development of Chemical Process Design and Control Sustainability. Processes, 4, 23, 2016. 125. Venselaar, J., The Role of Chemistry and Chemical Engineering in an Integral Approach for Transitions towards Sustainable Development. NPT Procestechnol., 6, 10–12, 2001. 126. Doyle, A., Applying Chemical Engineering in the Construction Industry. Chem. Eng., 2018. https://www.thechemicalengineer.com/features/applyingchemical-engineering-in-the-construction-industry/, 2018. 127. Sikdar, S., Journey Towards Sustainable Development: A Role for Chemical Engineers. Environ. Prog. Sustain. Energy, 22, 4, 2003. 128. Harold, M. and Ogunnaike, B., Process Engineering in the Evolving Chemical Industry. AIChE J, 46, 11, 2001. 129. Pike, R., Greenhouse Gas Management for Multiplant Complexes, in: Encyclopedia of Chemical Processing, S. Lee (Ed.), pp. 1190–1196, Taylor & Francis, Oxfordshire, United Kingdom, 2006. 130. Tuncia, C., Ramachandran, P.A., Dudukovic, M.P., Role of Chemical Reaction Engineering in Sustainable Process Development, in: Sustainability Science and Engineering: Defining Principles, M.A. Braham (Ed.), p. 335, Elsevier, USA, 2006. 131. Shuyun, L., Gaurav, M., Gerardo, R., Fernando, L., Development of Chemical Process Design and Control for Sustainability, Department of Chemical and Biomedical Engineering, West Virginia University, USA, 2016. 132. United States Environmental Protection Agency, Sustainable Manufacturing, https://www.epa.gov/sustainability/sustainable-manufacturing, 2018. 133. Hasna, A., Chemical Engineering Industry Transition Towards Sustainability, https://www.researchgate.net/publication/242486145_Chemical_ Engineering_Industry_Transition_Towards_Sustainability, 2018. 134. What is Cogeneration? Goldman Energy, http://goldman.com.au/energy/ company-news/what-is-cogeneration/, 2019. 135. Nnaji, U.P., Modern Occupational Guide for Nigerian Students, Revised Edition, pp. 41–46, Mecutex, Enugu, 2008. 136. Joback, K.G., Computer Aided Molecular Design (CAMD): Designing Better Chemical Products, http://www.molecularknowledge.com/Papers/CAMD/ camd.pdf, 2018. 137. Aspen HYSYS, https://www.aspentech.com/en/products/engineering/aspenhysys, 2016. 138. PROII, http://iom.invensys.com/EN/Pages/SimSci-Esscor_ProcessEngSuite_ PROII.aspx, 2016. 139. Piping, http://en.wikipedia.org/wiki/Piping, 2017.

344

References

140. Yeo, Y.K., Chemical Engineering Computation with MATLAB, CRC Press, New York, 2017. 141. Nnaji, U.P., Analysis of Port Harcourt Refinery Fluid Catalytic Cracking Unit to Optimize Unit Performance, Master of Engineering Management in Chemical Engineering Thesis, University of Port Harcourt, Rivers State, 2008. 142. Mary, S., Prospects for an Engineering Discipline of Software, Carnegie Mellon University, Pittsburgh, 1990. 143. Marquardt, W., Lars Von, W., Birget, B., Perspectives on Life Cycle Process Modeling, presented at AspenWorld 2000, Orlando, 2000. 144. Ignacio, E.G. and Arthur, W.W., Research Challenges in Process Systems Engineering, Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213. AIChE J, 46, 9, pp. 1700–1703, 2000. 145. Frontiers in Chemical Engineering Research Needs and Opportunities, pp. 201–204, National Academies Press, Washington, D.C, 1998. 146. Watters, J.C., A Course Module on Chemical Product Design, Chemical Engineering Department, University of Louisville, Louisville, http://folk. ntnu.no/skoge/prost/proceedings/aiche-2008/data/papers/P126880.pdf, 2017. 147. Post Graduate Study, www.prospects.ac.uk/p/types_of_job, 2017. 148. Chemical Engineering Education, http://www.che.ufl.edu/WWW-CHE/, 2015. 149. Biomedical engineer Salary, http://www.buzzle.com/articles/biomedicalengineer-salary.html, 2014. 150. Arora, A. and Gambardella, A., Evolution of industry structure in the chemical industry, in: Chemicals and Long-Term Economic Growth, A. Arora, R. Landau, N. Rosenberg (Eds.), pp. 379–414, John Wiley & Sons, New York, 1998. 151. Boston Latin School official website, www.bls.org, 2017. 152. UCDAVIS Chemical Engineering and Material Science, chms.engineering. ucdavis.edu/research/areas/synthesis/, 2015. 153. Nicholas, B., Opportunities in Engineering Careers, p. 160, McGraw-Hill Publishing, New York, 2003. 154. Committee on Chemical Engineering Frontiers, Research Needs and Opportunities, National Research Council, Washington, D.C., 2008. 155. Stankiewicz, A.I. and Moulijn, J.A., Process Intensification: Transforming Chemical engineering. Chem. Eng. Prog., 1, 22–31, 2000. 156. Process Control and Dynamic Course, http://www.cheme.utm.my/cheme/ index.php/cl/process-control-a-dynamics, 2014. 157. Ibrahim, T., Abdulrahman, R., Kamal, I., The Impact of Stripping Gas Flow Rate on Triethylene Glycol Losses from Glycol Regeneration Unit: Simulation Study. J. Chem. Eng. Process. Technol., 8, 337, 3, 4, 2017. 158. Nayak, R. and Mewada, R., Simulation of Coal Gasification Process Using ASPEN PLUS. Institute of Technology, Nirma University, Ahmadabad, 382 481, p. 4, International Conference on Current Trends in Technology, NUiCONE - 2011.

Index A Active safety instrument symbols, 263 Active safety system, 263 Active solutions, 264 Adhesives engineer, 162 Advanced combustion systems, 110 Agriculture, 332 AIChE fellow member, 77 AIChE member grades, 77 AIChE professional members, 77 AIChE senior member, 77 Alkylate, 48 Alternative energy, 331 Ammonia, 48 Andrew Grove, 100 Applications of interest, 2 Atmospheric gas oil (AGO), 304 Atmospheric ventilation unit, 32 AutoCAD engineer, 162 Automation engineer, 129 B Base chemicals, 111 Basic education, 37 Basic engineering design data (BEDD), 180 Basic engineering design, 178 Basic sciences, 41 Batch reactor, 48 Batch, 30 BEng, 38 Benzene, 283 Bio engineering, 320 Biochemical engineering, 320

Biochemical engineers, 118 Biochemists, 10 Biodiesel, 84 Bioengineering segment, 95 Biofuel, 113 Biomass gasification, 85 Biomass, 282 Biomaterials, 103 Biomedical engineer, 134 Biomedical engineering, 95 Biomedical, 95 Biomedicine, 95 Biotechnical engineer, 162 Biotechnology, 95, 320 Biotechnology-based chemicals, 96 Block flow diagram (BFDs) 190 Block process flow diagrams (BPFDs), 190 Bow-tie analysis, 265 Built-in safety system, 258 By-products, 109 C CAESAR 11, 311 Catalytic converters, 108 Calcium sulfide, 14 Capital expenditure (CAPEX), 181 Carbon footprint (CF), 279 Catalysis, 330 Catalysts, 336 Catalytic converters, 108 Cell culture, 66 Chemical and process engineers, 119 Chemical development engineer, 124

Uche Nnaji (ed.) Introduction to Chemical Engineering: For Chemical Engineers and Students, (345–351) © 2019 Scrivener Publishing LLC

345

346

Index

Chemical engineering applications, 44 Chemical engineering core subjects, 44 Chemical engineering core, 41 Chemical engineering laboratory core, 41 Chemical engineering lecturer, 162 Chemical engineering science, 22 Chemical engineering, 1 Chemical engineer-in-training, 67 Chemical engineers, 3 Chemical manufacturing engineer, 159 Chemical process engineering, 325 Chemical process reactions, 93 Chemical process risk engineer, 162 Chemical process safety, 253 Chemical reaction engineering, 45 Chemical reactions,94 Chemical reactor, 46 Chemical systems engineering, 23 Chemical vapor deposition process, 105 Chemical, 21 Chemistry core, 41 Chemistry, 7, 9 Chemists, 10 Clarified oil (CLO), 304 CO2 boiler, 26 CO2 emitters, 94 Coal, 86 Coalescing, 221 Column, 204 Commercial application, 48 Commissioning engineer, 126 Commissioning, 217, 251 Compressibility, 203 Compressors and blowers, 206 Computational fluid dynamics (CFD), 55 Computer chips materials, 105 Computer-aided design, 309 Computer-aided drafting, 309 Computer-aided molecular design, 309 Conceptual design, 178 Conceptual design, 247

Construction, 217, 248 Continuous, 30 Contracts engineer, 158 Controlled-atmospheric packaging (CAP), 94 Cost control engineer, 156 Cost engineer, 156 Critical experience, 164 Critical knowledge, 164 Critical leadership, 164 Critical thinking, 164 Cross-section area, 232 Crude oil, 55 Crystalline zeolite, 83 Crystallization process, 60 Crystallization, 60, 93 D Degree of separation, 227 Design core, 41 Design data, 228 Design parameters, 225 Design pressure, 225, 227 Design project, 41 Design temperature, 226 Desublimation, 60 Detailed process and engineering design, 208 Diabetes treatment, 98 Discovery chemists, 10 Discrete, 30 Distributed control system (DCS), 30 Drag force,223 Drilling engineer, 149 Drug delivery system, 98 Drying, 93 Dual compact flotation unit, 289 Dynamic systems and processes, 6 E Economic study, 241 Economic tools, 290 Education model, 37 Effluent treatment, 108

Index 347 Electives, 41 Electrical unit, 27 Electronics segment, 99 Energy and sustainability segment, 81 Energy transfer, 105 Energy, 21 Engineering chemistry, 45 Engineering design, 177 Engineering management, 331 Entropy, 50 Environment engineer, 151 Environment segment, 108 Equipment design Ethanol, 84 Experimental equipment, 9 External costs, 244 F Facilities process engineer, 141 Failure mode and effects analysis (FMEA), 265 Fats and oil, 113 Fault tree analysis (FTA), 265 FCC process flow, 305 Feasibility study, 178 Feedstock, 31 Fermentation, 66 Filtration, 93 Fine chemicals, 112 Firefighting unit, 35 Fixed-bed adsorption operation, 58 Flare knock-out drum, 219 Flare system, 33 Flare unit, 32 Flow rate, 227 FLUENT, 106 Fluid catalytic cracking unit, 301 Fluid catalytic cracking, 48, 301 Fluid flow processes, 20 Fluid flow, 53 Fluidized bed combustors, 48 Foam separation, 59 Food chemical engineers, 95, 90 Food engineering, 93

Food purification system, 94 Food segment, 90 Food technology, 93 Food, 21 Front-end engineering design, 185, 248 Froth flotation, 59 Fructose syrup, 58 Fuel cell, 88 G Gas chromatography (GC), 58 Gas residence time, 237 Gasoline blending stock, 48 General engineering, 41 General purpose technology, 7 George Davis, 14 Gibbs, free energy, 50 Gordon Moore, 100 Gravitational force on droplet, 223 Gravity settling, 222 Greenhouse gas (GHG), 109, 279 H Hazardous pollutants, 109 HAZID, 69 HAZOP methodology, 268 HAZOP, 69, 133, 265 Health, safety and environment, 253 Heat and material balance (H&MB), 193, 200 Heat exchangers, 54, 207 Heat flow, 202 Heat recovery process, 92 Heat recovery steam generator, 51 Heat transfer equipment (fired), 205 Heat transfer equipment (unfired), 205 Heat transfer processes, 20 Heat, 50 High pressure (HP), 197 High-temperature pasteurization, 94 Historical development, 12 Holly Lynch, 108 Horizontal flare knock-out drum, 320

348

Index

Hydrogen fuel, 87 Hydrogen gas, 87 Hydrophile, 59 Hydrotreatment, 108 HYSYS, 297 I IChemE affiliate member, 74 IChemE associate member, 74 IChemE chartered member, 75 IChemE fellow member, 75 IChemE student member, 74 IChemE technical member, 74 In/Out (I/O), 187 Industrial chemical reactor, 45 Industrial chemistry, 13 Inherent safety system, 258 Inherently safer design, 259 Inherently safer process, 255 Inorganic chemicals, 112 Inorganic, 1 Instrumentation and control, 328 Integrated combined-cycle gasification (IGCC), 87 Integrated control and safety systems (ICSS), 187 Internal costs, 244 Internal energy, 50 Internal rate of return (IRR), 180, 181 Intrinsic safety system, 258 Investment costs, 243 Irradiation, 94 K Kidney dialysis, 98 Kinetics and thermodynamics, 105 Kinetics, 330 Knock-out drum separator design, 221 Knock-out drum, 34, 218 KOD, 220 L Laboratory experiments, 170 Laboratory findings, 9

Laboratory, 21 Large-scale production, 10 Lay-down area, 34 Lay-out engineer, 153 Lean six sigma, 285 Leblanc process, 13 Level transmitter, 31 Lewis Norton, 15 Life cycle assessment (LCA), 280, 283, 284 Light cycle oil (LCO), 304 Light-emitting diodes (LEDs), 54, 99 Liquid drop out velocity, 238 Liquid droplet, 222, 223 Liquid hold-up, 233 Loss prevention and environment (LPE), 181 Loss prevention and environment, 209 Low pressure (LP), 197 Lower explosible limit (LEL), 261 Lower flammability limit (LFL), 261 M Magnetic field separation, 58 Maintenance engineer, 127 Maintenance planning engineer, 127 Mass density, 203 Mass flow, 202 Mass heat capacity, 203 Mass of droplet, 224 Mass transfer processes, 20 Mass transfer, 105 Material Science, 105 Material selection diagrams (MSD), 186 Materials engineer, 152 Materials engineering, 322 Materials segment, 101 MATLAB, 303 Mechanical engineering, 13 Mechanical integrity, 260 Mechanical processes, 20 Medical engineering, 320 Membrane-based separators, 94 MEng, 38

Index 349 Methyl isocyanate (MIC), 253 Metric tools, 290 Microbiologists, 10 Milling, 93 Mixers, 206 Mixing, 93 Modified atmospheric packaging (MAP), 94 Molar flow, 202 Molar weight, 202 Molecular weight, 224 Momentum, 221 N Nanoscience, 336 Natural science, 7, 11 Net present value (NPV), 181 New chemical engineering hire, 63 Newtonian liquids, 55 Nicholas Leblanc, 13 Non-proprietary equipment, 216, 245 Nozzles, 236 Nuclear biology, 331 Nuclear energy, 89 O Office building, 34 Oil and gas engineering, 325 Operating expenditure (OPEX), 181 Operating pressure, 225, 226 Organic chemicals, 112 Organic light-emitting diodes (OLEDs), 99 Organic, 1 Oxygen scavengers, 94 P Packaged units, 207 Packed columns, 204 Passive safety system, 260 Performance control engineer, 139 Personal protective equipment, 253 Petrochemical, 21 Petroleum engineer, 149

Petroleum oilfields chemicals, 113 Petroleum refining, 82 PFD review, 198 Pharmaceutical engineer, 142 Pharmaceutical engineering, 97 Pharmaceutical, 21 Pharmacists, 10 Pharmacokinetics, 46 Physical properties of, 227 Pipeline engineer, 147, 149 Piping and equipment design software, 311 Piping and instrumentation diagram (P&ID), 266 Piping design software, 311 Piping engineer, 153 Planning engineer, 140 Plant engineer, 141, 162 Plant gas metering unit, 26 Plant operation, 252 Plastic materials, 103 Plastics engineer, 162 Pollution control systems, 110 Polymer engineer, 162 Polymer engineering, 326 Polymer science, 105 Potassium carbonate, 13 Power unit, 27 Pre-commissioning, 217, 251 Presentation software, 313 Pressure control valve, 31 Pressure gauge, 31 Pressure indicator, 31 Pressure relief valve, 262 Pressure transmitter, 31 Pressure, 59, 202 Pressure-relief system, 33, 218 Preventive design features, 261 Primary separation, 222 PRO II, 297 Procedural control, 264 Process and equipment design, 329 Process and technology development, 168

350

Index

Process automation, 328 Process control and automation engineer, 130 Process control engineer, 129 Process control, 29, 60 Process design, 172, 256 Process dynamics and control, 60 Process engineering design software, 297 Process engineering, 209 Process equipment cost estimate, 242 Process equipment, 215 Process evaluation, 174 Process flow diagrams (PFDs), 192 Process hazard analysis, 92, 264 Process intensification, 335 Process interconnecting piping, 27 Process laboratory, 28 Process maintenance engineer, 127 Process over-design, 260 Process safety design verification, 273 Process safety engineer, 131 Process safety factor, 260 Process safety information (PSI), 273 Process safety management, 274 Process safety model, 254 Process safety unit, 257 Process simulation engineer, 162 Process synthesis and design, 172 Process synthesis, 172 Process system engineering (PSE), 323 Process tools, 290 Process units, 25 Processes of interest, 2 Product engineering, 334 Product evaluation and marketing, 176 Production engineer, 146 Products of interest, 2 Programmable logic controller (PLC), 29 Project control engineer, 162 Project engineer, 155 Project services engineer, 162 Propellant slurries, 107

Propellants, 107 Proportional-integral-derivative (PID), 62 Proprietary equipment, 216, 245 Protective design features, 261 Protein skimmers, 59 Pulp and paper engineer, 162 Pump-out capacity, 232 Pumps, 206 Purification, 57 Purification, 94 Q Quality control engineer, 160 Quality process engineer, 160 R Radioactive materials, 90 Reaction engineering, 330 Reactors, 205 Refinery engineer, 123 Refining, 21 Reformate, 48 Refrigeration and freezing, 94 Renewable energy, 88 Research and development engineer, 136 Reservoir engineer, 149 Reverse osmosis, 93 Rheology, 107 Runaway reactions, 256 S Safety administrative control, 264 Safety relief valve, 33 Sales engineer, 138 Samson Jenekhe, 99 Secondary separation, 222 Sedimentation, 26 Semiconductor chip, 100 Separation process, 55, 93 Separators, 206 Shut-down valve, 31 Silicon wafers, 105

Index 351 Silicon, 100 Single-walled carbon nanotubes (SWNT), 106 Sir Arthur Fleming, 79 Site engineer, 144 Sodium carbonate, 13 Solar energy, 88 Solvay process, 13 Space program, 106 Specific heat, 50 Spherical silicon solar cells (SSSC), 106 Start-up, 217 Std liquid flow, 204 Storage tanks, 31 Structured product engineering, 327 Sulfuric acid production, 13 Sulfuric acid, 13 Supervisory control and data acquisition (SCADA), 30 Surface science, 336 Surface tension, 204 Sustainability, 278 Sustainable behavior, 285 Sustainable consumption, 285 Sustainable manufacturing process, 283 Sustainable model, 279 Sustainable raw materials, 282 Synthetic fuel, 84 Synthetic liquid fuels, 84 Synthetic rubber, 80 System pressure, 224 Systems of interest, 2 T Tanks, 207 Technical function flow sheets (TFFs), 190 Telecommunication materials, 104 Temperature indicator, 31 Temperature transmitter, 31 Temperature, 50, 202

Thermal conductivity, 203 Thermodynamic processes, 20 Thermodynamics, 49 Three-phase separator, 223 Tissue engineering, 95 Towers, 207 Trainee chemical engineer, 65 Training, 37 Transport phenomena, 52, 55 Transport processes, 52 Tray columns, 204 U Unit operations, 19 Universal engineers, 6 Universal gas constant, 50 V Vapor allowed velocity, 221 Vapor densities, 229 Vapor fraction, 202 Vapor/liquid separation, 222 Vessels, 205 Viscosity, 203 Volume, 50 W Wafer, 101 Warehouse and storage, 35 Warren Lewis, 20 Waste management engineer, 162 Waste treatment engineer, 162 Water generation unit, 36 William McAdams, 20 William Walker, 20 Wind energy, 88 Work, 50 Workshop area, 34 X Xylene, 58