WIlllAM 1. LUYBENWILLIAM 1. LUYBEN I

PROCESS MODELING,PROCESS MODELING, lSIMULATION ANDSIMULATION AND\

CONTROL iOR5

CONTROL FlitI mCHEMICAL ENGINEERS m

SECOND EDITION- Ia I1L

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PROCESS MODELING,SIMULATION, AND

CONTROL FORCHEMICAL ENGINEERS

Second Edition

William L. LuybenProcess Modeling and Control Center

Department of Chemical EngineeringLehigh University

McGraw-Hill Publisbing CompanyNew York St. Louis San Francisco Auckland Bogota Caracas Hamburg

Lisbon London Madrid Mexico Milan Montreal New DelhiOklahoma City Paris San Juan SHo Paul0 Singapore Sydney Tokyo Toronto

PROCESS MODELING, SIMULATION, AND CONTROL FORCHEMICAL ENGINEERSINTERNATIONAL EDITION 1996

Exclusive rights by McGraw-Hill Book Co.- Singapore formanufacture and export. This book cannot be m-exportedfrom the country to which it is consigned by McGraw-Hill.

567690BJEPMP9432

Copyright e 1999, 1973 by McGraw-Hill, Inc.All rights reserved. Except as permitted under the United States CopyrightAct of 1976, no part of this publication may be reproduced or distributed inany form or by any means, or stored in a data base or retrieval system, uwithout the prior written permission of the publisher.

This book was set in Times Roman.The editors were Lyn Beamesderfer and John M. Morris.%The production supervisor was Friederich W. Schulte.The cover was designed by John Hite.Project supervision was done by Harley Editorial Services.

Ubrury of Congress Cataloging-in-Publlcatlon Data

William L. Luyben.-2nd ed.p. cm.

Bibliography: p.Includes index.ISBN 6-67-639159-91. Chemical process-Math

data processing., 3. ChemicaTP155.7.L66 1 9 6 9 ,669.261-dc19

When ordering this title use ISBN

1process

No.DEADQUiSICION

fespindolaWilliam L. Luyben.-2nd ed.p. cm.Bibliography: p.Includes index.ISBN 6-67-639159-91. Chemical process-Mathdata processing., 3. ChemicaTP155.7.L66 1 9 6 9 ,669.261-dc19When ordering this title use ISBN1processNo.DEADQUiSICION

fespindolaBibliography:Includes index.ISBN 6-67-639159-1. Chemicaldata processing.,TP155.7.L66 1669.261-dc19When ordering this

fespindola

ABOUT THE AUTHOR

William L. Luyben received his B.S. in Chemical Engineering from the Penn-sylvania State University where he was the valedictorian of the Class of 1955. Heworked for Exxon for five years at the Bayway Refinery and at the AbadanRefinery (Iran) in plant. technical service and design of petroleum processingunits. After earning a Ph.D. in 1963 at the University of Delaware, Dr. Luybenworked for the Engineering Department of DuPont in process dynamics andcontrol of chemical plants. In 1967 he joined Lehigh University where he is nowProfessor of Chemical Engineering and Co-Director of the Process Modeling andControl Center.

Professor Luyben has published over 100 technical papers and hasauthored or coauthored four books. Professor Luyben has directed the theses ofover 30 graduate students. He is an active consultant for industry in the area ofprocess control and has an international reputation in the field of distillationcolumn control. He was the recipient of the Beckman Education Award in 1975and the Instrumqntation Technology Award in 1969 from the Instrument Societyof America. f

r.-.,.,y

This book is dedicated toRobert L. Pigford and Page S. Buckley,

two authentic pioneersin process modelingand process control

CONTENTS

11.1

1 .21 .31 .41 .51 .6

Part I

Preface

Introduction 1Examples of the Role of Process Dynamicsand ControlHistorical BackgroundPerspectiveMotivation for Studying Process ControlGeneral ConceptsLaws and Languages of Process Control1.6 .1 Process Control Laws1.6.2 Languages of Process Control

16788

11111 2

Mathematical Models ofChemical Engineering Systems

Xxi

2 Fundamentals2 .1 Intreduction

2.1.1 Uses of Mathematical Models2.1.2 Scope of Coverage2.1.3 Principles of Formulation

2.2 Fundamental Laws2.2.1 Continuity Equations2.2.2 Energy Equation2.2.3 Equations of Motion2.2.4 Transport Equations2.2.5 Equations of State2.2.6 Equilibrium2.2.7 Chemical KineticsProblems

1 5

1 51 51 61 61 71 72 32 73 13 23 33 63 8

xi

I

4

X i i C O N T E N T S

3

3 .13 .23 .33.43 .53.63.73.83 .9

3.103.113.123.133.14

Part II

Examples of Mathem