Handbook of Batch Process Design

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Handbook of Batch Process Design

Edited by

P.N. SHARRATT Department of Chemical Engineering

UMIST Manchester, UK

lOJ BLACKIE ACADEMIC & PROFESSIONAL

An Imprint of Chapman & Hall

London· Weinheim . New York· Tokyo· Melbourne· Madras

Published by Blackie Academic and Professional, an imprint of Chapman & Hall, 2-6 Boundary Row, London SEt 8HN, UK

Chapman & Hall, 2-6 Boundary Row, London SEI 8HN, UK

Chapman & Hall GmbH, Pappelallee 3, 69469 Weinheim, Germany

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Chapman & Hall India, R. Seshadri, 32 Second Main Road, CIT East, Madras 600 035, India

First edition 1997 CD 1997 Chapman & Hall

Softcover reprint of the hardcover 1 st edition 1997

Typeset in IOjl2pt Times by Academic & Technical Typesetting, Bristol

ISBN-13: 978-94-010-7150-5 e-ISBN-13: 978-94-009-1455-1 DOl: 10.1007/978-94-009-1455-1

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the UK Copyright Designs and Patents Act, 1988, this publication may not be reproduced, stored, or transmitted, in any form or by any means, without the prior permission in writing of the publishers, or in the case of repro graphic reproduction only in accordance with the terms of the licences issued by the Copyright Licensing Agency in the UK, or in accordance with the terms of licences issued by the appropriate Reproduction Rights Organization outside the UK. Enquiries concerning reproduction outside the terms stated here should be sent to the publishers at the London address printed on this page.

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A catalogue record for this book is available from the British Library

Library of Congress Catalog Card Number: 97-71787

@Printed on acid-free text paper, manufactured in accordance with ANSIj NISO Z39.48-1992 (Permanence of Paper).

Contents

List of contributors

Preface

Acknowledgements

1

2

Chemicals manufacture by batch processes P.N. SHARRATT

1.1 Introduction 1.2 Industrial background

1.2.1 Definitions 1.2.2 Product life cycles and regulatory influences

1.3 Reasons for the use of batch processing 1.4 Batch process design for fine and speciality chemical production

1.4.1 Process chemistry 1.4.2 Process design 1.4.3 Unit operations 1.4.4 Process operation and control 1.4.5 Health, safety and environmental issues during operation

1.5 Plant design 1.6 Summary References

Scheduling and simulation of batch processes G.V. REKLAITIS, 1. PEKNY and G.S. 10GLEKAR

2.1 Introduction 2.2 Batch process features 2.3 The scheduling problem

2.3.1 General features 2.3.2 Generic solution approaches 2.3.3 Uniform discretization scheduling approach 2.3.4 Requirements for implementation

2.4 Batch process simulation 2.4.1 The role of simulation 2.4.2 Simulation model features 2.4.3 Elements of combined simulation 2.4.4 Limitations of discrete simulation languages 2.4.5 Features of a process-oriented combined simulator

2.5 Design implications References

xi

xiii

xiv

1

I 2 2 5 7 8 9

l3 17 18 20 21 22 22

24

24 24 29 29 31 35 38 40 40 41 41 48 50 57 58

vi

3

4

CONTENTS

Solvents in chemicals production M. SHEEHAN

3.1 Introduction 3.2 Solvent properties

3.2.1 Chemical properties 3.2.2 Physical properties

3.3 Solubility 3.3.1 Non-specific intermolecular forces 3.3.2 Specific intermolecular forces 3.3.3 Energy of solvation 3.3.4 Selective solvation 3.3.5 Solvent mixtures 3.3.6 Supercritical solvents

3.4 Solvent effects on reactions 3.4.1 Rules of thumb - Hughes-Ingold rules 3.4.2 The transition state approach 3.4.3 Solvation dynamics 3.4.4 Reaction examples 3.4.5 Heterogeneous reactions

3.5 Solvent recovery 3.5.1 Origin of solvent wastes 3.5.2 Designing for recovery 3.5.3 Separation of solvents from gaseous wastes 3.5.4 Separation of solvents as liquid

3.6 Solvent destruction 3.6.1 Non-biological treatment 3.6.2 Biological treatment

3.7 Conclusion 3.8 Nomenclature References

Agitation K.J. CARPENTER

4.1 Agitator selection 4.1.1 Agitator duties 4.1.2 Agitator types

4.2 Calculation of agitator power, discharge flow and mixing time 4.2.1 Typical power levels 4.2.2 Calculation of power 4.2.3 Discharge flow 4.2.4 Mixing time

4.3 Power and circulation in non-Newtonian fluids 4.3.\ Calculation of power 4.3.2 Circulation

4.4 Design to disperse solid particles 4.4.1 Disperse sinking particles 4.4.2 Draw down floating particles

4.5 Design for two or more liquid phases 4.5.\ Miscibility 4.5.2 Phase continuity and phase inversion 4.5.3 Phase distribution - the just dispersed condition 4.5.4 Drop sizes 4.5.5 Mass transfer

61

61 62 62 63 71 72 74 75 76 76 77 77 78 79 81 82 87 90 90 91 94 95

101 101 102 104 105 105

107

107 107 108 114 114 114 115 116 117 117 118 119 119 120 121 121 123 125 127 129

5

6

7

4.6 Design for dispersing gas 4.6.1 Sparged gas

CONTENTS

4.6.2 Sparged with surface incorporation 4.6.3 Specialized gas-inducing impellers 4.6.4 Mass transfer

4.7 Design for heat transfer 4.7.1 Heat transfer surfaces 4.7.2 Service side heat transfer coefficient 4.7.3 Process side heat transfer coefficient 4.7.4 Wall resistance

4.8 Nomenclature References

Mixing and the selectivity of fast chemical reactions J.R. BOURNE

5.1 The problem 5.2 Mixing mechanisms and modelling

5.2.1 Semi-batch reactor: micromixing 5.2.2 Extensions

5.3 Applications 5.3.1 Model reactions 5.3.2 Characterization of mixers 5.3.3 Scale-up principles

5.4 Extensions 5.5 Concluding remarks 5.6 Nomenclature References

Batch filtration of solid-liquid suspensions A.RUSHTON

6.1 Introduction 6.2 Filtration ptocess fundamentals

6.2.1 Flow of fluids in filtration 6.2.2 Quantitative relationship for cake filtration 6.2.3 Laboratory tests and filter media in cake filtration 6.2.4 Application of basic relationships to centrifugal filters 6.2.5 Filter cake washing 6.2.6 Filter cake dewatering 6.2.7 Clarification filtration processes 6.2.8 Laboratory tests and filter media in clarification processes 6.2.9 Membrane filtration principles

6.3 Batch operated filtration machinery 6.3.1 Pressure-vacuum filters 6.3.2 Centrifugal filters 6.3.3 Membrane filters

6.4 Nomenclature References

Design and engineering of a batch plant M.J. MAYES

7.1 Introduction 7.2 Project definition 7.3 Project strategy

vii

130 130 131 131 131 132 132 133 135 136 136 137

139

139 141 141 144 145 145 147 148 149 149 150 150

153

153 155 155 157 159 165 166 168 169 171 174 177 177 185 186 189 190

193

193 193 194

viii

8

7.4 Project organization 7.5 'Fast track' projects

7.5.1 Techniques 7.5.2 Problems

CONTENTS

7.6 Regulations and other controls 7.6.1 Hazard and operability (HAZOP) studies 7.6.2 Environmental impact studies 7.6.3 Fire and explosion hazards 7.6.4 Construction safety

7.7 Design techniques 7.7.1 Case study - design for ease of construction

7.8 Layout considerations 7.8.1 Case study - layout

7.9 Plant relocation/reuse of existing equipment 7.9.1 Case study - plant relocation

7.10 Modular plant

Control P.E. SAWYER

8.1 Introduction 8.2 Control of continuous processes 8.3 Control of batch processes

8.3.1 A simple example 8.3.2 Multiproduct, multistream and multipurpose operations

8.4 Batch control systems - structure and functions 8.4.1 Models and terminology - the SP88 standard 8.4.2 Models for batch processing

8.5 Computer control 8.5.1 Introduction 8.5.2 Systems architecture - hardware and software 8.5.3 Choosing an architecture 8.5.4 Hardware 8.5.5 Software

8.6 Procedural control 8.6.1 Introduction 8.6.2 Identifying procedures 8.6.3 Specifying procedures

8.7 Acknowledgements References

9 Hazards from chemical reactions and flammable materials in batch reactor operations R. ROGERS

9.1 Introduction 9.2 Hazard identification

9.2.1 The defined procedure 9.3 Chemical reaction hazards

9.3.1 Thermal explosions 9.3.2 Characterization of the desired reaction 9.3.3 Characterization of exothermic decomposition reactions 9.3.4 Selection of safety measures

195 198 198 201 202 202 204 204 205 205 207 208 210 212 217 217

219

219 220 220 220 223 225 225 226 235 235 236 237 238 243 243 243 244 244 251 251

253

253 254 255 257 259 262 263 267

CONTENTS ix

9.4 Fire and explosion hazards 270 9.4.1 Flammability characteristics of materials 271 9.4.2 Sources of ignition 280 9.4.3 Assessment of hazards and definition of appropriate safety measures 283

9.4 Conclusions 287 References

10 Environmental protection and waste minimization C. JONES

10.1 Introduction 10.2 Batch reactor waste minimization

10.2.1 Process chemistry 10.2.2 Heat effects 10.2.3 Mixing and contacting pattern

10.3 Equipment for the production of solid products 10.3.1 Crystallization processes 10.3.2 Precipitation processes 10.3.3 Solid-liquid separation 10.3.4 Batch drying

10.4 Fugitive and other minor emissions 10.5 Cleaning wastes 10.6 Waste treatment and solvent management 10.7 Environmental protection 10.8 Conclusions References

11 Future developments in batch process design and technology P.N. SHARRATT

11.1 Influences for and against change 11.2 New technologies

11.2.1 New or enhanced unit operations 11.2.2 New plant designs 11.2.3 Process intensification

II. 3 New processes 11.4 New design methods 11.5 New skill requirements References

Index

289

289 291 291 291 292 292 294 294 294 300 301 303 304 305 306

308

308 309 309 310 311 312 312 313 313

315

List of contributors

J. Bourne

K.J. Carpenter

G.S. Joglekar

C. Jones

J. Mayes

J. Pekny

G.V. Reklaitis

R. Rogers

A. Rushton

P. Sawyer

Vine House, Ankerdine Road, Cothridge, Worcester WR6 5LU, UK

Process Technology Department, Zeneca pic, Huddersfield Works, Huddersfield HD2 IFF, UK

Batch Process Technologies, 1291E Cumberland Ave., PO Box 2001, W. Lafayette, IN 47906, USA

Fluor Daniel Limited, Process Department, Fluor Daniel Centre, Camberley, Surrey GU15 3YL, UK

Simon Carves, Sim-Chem House, PO Box 17, Cheadle Hume, Cheshire SK8 5BR, UK

School of Chemical Engineering, Chemical Engineering Building, Purdue University, West Lafayette, IN 47907, USA

School for Chemical Engineering, Chemical Engineering Building, Purdue University, West Lafayette, IN 47907, USA

Imburex GmbH, Wilhelmstrasse 2, 59067 Hamm, Germany

Department of Chemical Engineering, UMIST, PO Box 88, Manchester M60 lQD, UK

PES Associates, 44 High Street, Chippenham, Wiltshire SN14 8LP, UK

XII

P.N. Sharratt

M. Sheehan

LIST OF CONTRIBUTORS

Environmental Technology Centre, Department of Chemical Engineering, UMIST, PO Box 88, Manchester M60 lQD, UK

Department of Chemical Engineering, UMIST, PO Box 88, Manchester M60 lQD, UK

Preface

The use of batch processes for the manufacture of fine and effect organic chemicals is widespread and underpins such industry sectors as pharma­ceuticals, dyestuffs and agrochemicals. Despite their great contribution to wealth creation, batch processes have attracted relatively little attention from the academic world and have not been associated with large invest­ments in industrial process technology research.

Batch process design has a number of core techniques and technologies that are common to most industry sectors. Scheduling and sequence control are both significant topics that do not arise in the design of continuous processes. The development and implementation of robust, efficient schedules is essential in both design and operation of batch processes. Mixing and agitation have a central role due to the widespread use of liquid-phase reactions and stirred vessels. Agitators are required for blend­ing, dispersing two or more immiscible phases, promoting high reaction yields and numerous other duties. Incorrect agitation system design can give rise to dramatic yield loss, inefficient processes and possibly even hazar­dous situations. Batch products are often solids, so solid-liquid separations are important. Batch filtration equipment comes in many forms and selection of the right system is essential to avoid operational difficulties. Solvents are frequently used, and have a major influence on process design through their impact on reaction rates and separations. An understanding of the underly­ing molecular mechanisms for the interaction of solvent and solute gives a better chance of manipulating processes for enhanced performance. Batch organic chemical processes raise distinctive safety and environmental issues, linked to the use of solvents as well as the reactivity of many of the materials used. Finally, project management and engineering tend to be different in batch processes where 'fast track' projects and equipment reuse are the norm rather than the exception.

The literature on the topics mentioned above is fragmented and often not in a readily accessible form. This handbook brings together design and process analysis methods in the core areas of batch process design. It is intended primarily for practising technologists in the batch process indus­tries, as well as consultants and contractors servicing those industries. It should also be useful to academics and students working in the area, both as a reference and an insight into some of the problems of this sector.

Acknowledgements

The editor would like to acknowledge the patience and good humour of his family, Susan, James and William during the preparation of this book. He would also like to thank his former colleagues in Zeneca pIc for introducing him to the challenges of batch processing and inspiring this book.