Excerpts

Preface This book is intended to serve as an introduction to the principles and techniques used in the field of chemical, petroleum, and environmental engineering. Although the range of subjects deemed to be in the province of "chemical engineering" has broadened over the last decade, the basic principles involved in chemical engineering remain the same. This book lays a foundation of certain information and skills that can be repeatedly employed in subsequent courses as well as in professional life. New Features in the Seventh Edition The seventh edition is a completely rewritten and revised version of Basic Principles and Calculations in Chemical Engineering. Instead of five long chapters, the book is now comprised of 32 short chapters, each typically corresponding to one class session in a schedule of three meetings a week. New features include: A consistent, sound strategy for solving material balance and energy balance problems, one can be used again and again as a framework for solving word problems, which is explained in Chapter 7. All of the examples in this book showing how to solve material and energy balances have been formulated according to this strategy. The examples and problems in each chapter have been augmented to include expanded areas of importance to chemical engineers such as safety, semiconductor processing, and biotechnology. The chapters on material balances have been revised to offer practice in finding out what the problem is, defining it, collecting data to be used in the problem, analyzing the information pertaining to the problem in order to relate it to what you know about similar problems, and, in effect, doing everything but testing the solution experimentally. The extent of reaction has been added to the tools used to solve problems involving chemical reactions. The degree of freedom analysis in solving problems has been emphasized and simplified. A glossary has been added to each chapter. On the CD that accompanies this book is A new version of Polymath, a self-documented, widely used software package that runs on PCs and can solve linear, nonlinear, and differential equations as well as regression problems. A new physical properties database that contains retrievable physical properties (such as vapor pressures and heat capacities and enthalpies for 740 compounds plus the steam tables). Our Motivation for Writing This Book Far too many chemical engineering textbooks have become difficult, dry, and demoralizing for their readers. With this book, we have maintained a conversational style and detailed explanation of principles both in the text and examples to provide a readable yet comprehensive text. We have strived to maintain a suitable balance between understanding and developing skills. Our vision is to avoid comments (from a student about a different text) such as: "My text is useless, well not really, I use it to kill roaches in my room." Piaget has argued that human intelligence proceeds in stages from the concrete to the abstract and that one of the biggest problems in teaching is that the teachers are formal reasoners (using abstraction) while many students are still concrete thinkers or at best in transition to formal operational thinking. We believe that there is considerable truth in this viewpoint. Consequently, we initiate most topics with simple examples that illustrate the basic ideas. In this book the topics are presented in order of assimilation. We start with easy material followed by more difficult material to give readers a "breather" before passing over each hump. Assumed Prerequisites The level of the book is directed to the first course in chemical engineering, which usually occurs in a student's sophomore year. We have assumed that you as a reader to have completed the second part of calculus and started organic chemistry. Familiarity with hand-held calculators is essential, but computer programming is not. Familiarity with PC software would be helpful, but is not critical. Intended Audience We believe that the main category of individuals who will use this book will be students of chemical engineering. However, the book is well designed for courses for nonchemical engineers as well as independent study, long-distance learning, and review for licensing examinations through its self-assessment features. Our Objectives This book is not an introduction to chemical engineering as a profession. We have focused instead on five general objectives in writing this book: To introduce you to the principles and calculation techniques used in chemical engineering. To acquaint you with what material and energy balances are, and how to formulate and solve them. To assist you in learning efficient and consistent methods of problem solving so that you can effectively solve problems you will encounter after leaving school. To offer practice in defining problems, collecting data, analyzing the data and breaking it down into basic patterns, and selecting pertinent information for application. To review certain principles of applied physical chemistry. In addition to focusing on the five above objectives, we expose you to background information on units and measurements of physical properties; basic laws about the behavior of gases, liquids, and solids; and some basic mathematical tools. Other objectives that an instructor may want to include in a course, such as programming and communication skills, information about professional activities, developing a professional attitude, establishing personal goals, developing social awareness, and so on, must be implemented from other sources. Economic feasibility, a major factor in engineering decision making, costing, and optimization, have been omitted because of lack of space. We have not focused on using process simulation software to analyze and solve problems even though it is very good in exploring and handling "what if" questions as well as removing some of the drudgery in solving problems because 1. the pedagogy is too closely aligned to cookbook-style problem solving; learning how to use the software with ease takes some time; and development of a problem-solving strategy is taken out of the hands of the user by the software programmers. The software provides too much guidance for neophytes. Organization and Scope of this Book The major portion of the book comprises four parts: Part 1. Background information (Chapters 1-5) Part 2. Material balances (Chapters 6-12) Part 3. Behavior of gases, liquids, and solids (Chapters 13-20) Part 4. Energy balances (Chapters 21-29) In addition, on the accompanying CD, Chapter 30 treats the degrees of freedom, Chapter 31 process simulators, and Chapter 32 unsteady state material and energy balances. A series of appendices follow that include, in addition to tables and charts of physical properties, miscellaneous information you will find useful. Look at the Table of Contents for details. In the CD that accompanies this book you will find several valuable tools: Polymath: Software that solves equations, and can be used without reading any instructions. Software to retrieve physical property data for over 740 compounds. A Supplementary Problems Workbook containing 100 problems with complete detailed solutions, and another 100 problems with answers. Descriptions of process equipment, and animations that illustrate the functions of the equipment. Problem-solving suggestions including check lists to help you diagnose and overcome problem-solving difficulties you may experience. To provide an appreciation of what processing equipment really looks like and how it works, in the files on the CD disk in the worked-out problems are numerous pictures of the equipment along with an explanation of their function and operation. Problem Sets We have included several categories of problems in the books to assist in self-study. Self-assessment tests with answers (in Appendix A) follow each section. Thought and discussion problems follow the self-assessment tests. Thought problems require reflection more than calculation. Discussion problems, which can be used as the basis of research, papers, and class discussions, pertain to broader issues and are more open ended. Homework-type problems are listed at the end of each chapter, one-third of which have answers (in Appendix N). Each of the problems is rated 1 to 3 (using asterisks) to indicate the degree of difficulty, with 3 being the most difficult. The CD contains more than 100 worked-out examples and another 100 problems with answers keyed to sections in the chapters in the text. All of the examples and problems are designed to build your problem-solving skills. Miscellaneous Useful Features in this Book To make the book more usable and friendly, we have incorporated a number of beneficial features: A list of contents at the beginning of each chapter. A list of instructional objectives at the beginning of each chapter. Important terms appear in boldface type. A glossary has been placed at the end of each chapter. Supplementary references that you can use to get additional information are listed at the end of each chapter. Web sites containing information and links are listed at the end of each chapter. The examples are simple and concrete so that the book is both teachable and useful for self instruction. The chapter topics are independent but linked through a few principles. The examples demonstrate a proven problem-solving strategy. Excerpted from Basic Principles and Calculations in Chemical Engineering by David M. Himmelblau, James B. Riggs All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.