Pinch Analysis and Process Integration (eBook)

Front Cover 1
Pinch Analysis and Process Integration 4
Copyright page 5
Contents 6
Foreword 13
Foreword to the first edition 14
Preface 15
Acknowledgements 17
Figure acknowledgements 18
Chapter 1: Introduction 20
1.1 What is pinch analysis? 20
1.2 History and industrial experience 21
1.3 Why does pinch analysis work? 23
1.4 The concept of process synthesis 24
1.5 The role of thermodynamics in process design 28
1.5.1 How can we apply thermodynamics practically? 28
1.5.2 Capital and energy costs 28
1.6 Learning and applying the techniques 30
Chapter 2: Key concepts of pinch analysis 34
2.1 Heat recovery and heat exchange 34
2.1.1 Basic concepts of heat exchange 34
2.1.2 The temperature–enthalpy diagram 35
2.1.3 Composite curves 38
2.1.4 A targeting procedure: the "Problem Table" 40
2.1.5 The grand composite curve and shifted composite curves 44
2.2 The pinch and its significance 46
2.3 Heat exchanger network design 48
2.3.1 Network grid representation 48
2.3.2 A "commonsense" network design 49
2.3.3 Design for maximum energy recovery 50
2.3.4 A word about design strategy 54
2.4 Choosing & #916
2.4.1 Further implications of the choice of & #916
2.5 Methodology of pinch analysis 57
2.5.1 The range of pinch analysis techniques 57
2.5.2 How to do a pinch study 57
Exercise 58
Chapter 3: Data extraction and energy targeting 60
3.1 Data extraction 60
3.1.1 Heat and mass balance 60
3.1.2 Stream data extraction 61
3.1.3 Calculating heat loads and heat capacities 62
3.1.4 Choosing streams 64
3.1.5 Mixing 66
3.1.6 Heat losses 66
3.1.7 Summary guidelines 68
3.2 Case study: organics distillation plant 68
3.2.1 Process description 68
3.2.2 Heat and mass balance 68
3.2.3 Stream data extraction 71
3.2.4 Cost data 71
3.3 Energy targeting 72
3.3.1 & #916
3.3.2 Threshold problems 73
3.4 Multiple utilities 75
3.4.1 Types of utility 75
3.4.2 The Appropriate Placement principle 76
3.4.3 Constant-temperature utilities 77
3.4.4 Utility pinches 78
3.4.5 Variable-temperature utilities 79
3.4.6 Balanced composite and grand composite curves 81
3.4.7 Choice of multiple utility levels 86
3.5 More advanced energy targeting 86
3.5.1 Zonal targeting 86
3.5.2 Pressure drop targeting 87
3.6 Targeting heat exchange units, area and shells 88
3.6.1 Targeting for number of units 88
3.6.2 Targeting for the minimum number of units 91
3.6.3 Area targeting 92
3.6.4 Deviations from pure countercurrent flow 95
3.6.5 Number of shells targeting 95
3.6.6 Performance of existing systems 95
3.6.7 Topology traps 96
3.7 Supertargeting: cost targeting for optimal & #916
3.7.1 Trade-offs in choosing & #916
3.7.2 Illustration for two-stream example 99
3.7.3 Factors affecting the optimal & #916
3.7.4 Approximate estimation of ideal & #916
3.8 Targeting for organics distillation plant case study 104
3.8.1 Energy targeting 104
3.8.2 Area targeting 104
3.8.3 Cost targeting 106
3.8.4 Zonal targeting 109
3.8.5 Targeting with utility streams included 111
3.9 Appendix: Algorithms for Problem Table and composite curves 114
3.9.1 Problem Table and GCC 114
3.9.2 Composite curves 115
Exercises 116
Chapter 4: Heat exchanger network design 118
4.1 Introduction 118
4.2 Heat exchange equipment 118
4.2.1 Types of heat exchanger 118
4.2.2 Shell-and-tube exchangers 119
4.2.3 Plate exchangers 122
4.2.4 Recuperative exchangers 125
4.2.5 Heat recovery to and from solids 125
4.2.6 Multi-stream heat exchangers 126
4.3 Stream splitting and cyclic matching 127
4.3.1 Stream splitting 127
4.3.2 Cyclic matching 133
4.3.3 Design away from the pinch 133
4.4 Network relaxation 136
4.4.1 Using loops and paths 136
4.4.2 Network and exchanger temperature differences 142
4.4.3 Alternative network design and relaxation strategy 142
4.5 More complex designs 144
4.5.1 Threshold problems 144
4.5.2 Constraints 146
4.6 Multiple pinches and near-pinches 149
4.6.1 Definition 149
4.6.2 Network design with multiple pinches 150
4.7 Retrofit design 151
4.7.1 Alternative strategies for process revamp 151
4.7.2 Network optimisation 154
4.7.3 The network pinch 154
4.7.4 Example retrofit network design 156
4.7.5 Automated network design 162
4.8 Operability: multiple base case design 164
4.9 Network design for organics distillation case study 167
4.9.1 Units separate 167
4.9.2 Units integrated 171
4.9.3 Including utility streams 173
4.9.4 Multiple utilities 173
4.10 Conclusions 176
Exercises 176
Chapter 5: Utilities, heat and power systems 180
5.1 Concepts 180
5.1.1 Introduction 180
5.1.2 Types of heat and power systems 180
5.1.3 Basic principles of heat engines and heat pumps 181
5.1.4 Appropriate placement for heat engines and heat pumps 183
5.2 CHP systems 186
5.2.1 Practical heat engines 186
5.2.2 Selection of a CHP system 187
5.2.3 Refinements to site heat and power systems 191
5.2.4 Economic evaluation 196
5.2.5 Organic Rankine cycles 201
5.3 Heat pumps and refrigeration systems 203
5.3.1 Heat pump cycles 203
5.3.2 Refrigeration systems 207
5.3.3 Shaft work analysis 210
5.3.4 Cooling water systems 211
5.3.5 Summary 212
5.4 Total site analysis 213
5.4.1 Energy targeting for the overall site 214
5.4.2 Total site profiles 215
5.4.3 Practical heat recovery through the site steam system 216
5.4.4 Indirect heat transfer 217
5.4.5 Estimation of cogeneration targets 219
5.4.6 Emissions targeting 220
5.5 Worked example: organics distillation unit 221
5.6 Case studies and examples 224
5.6.1 Whisky distillery 224
5.6.2 CHP with geothermal district heating 227
5.6.3 Tropical power generation and desalination 228
5.6.4 Hospital site 229
Exercises 229
Chapter 6: Process change and evolution 232
6.1 Concepts 232
6.2 General principles 234
6.2.1 The basic objective 234
6.2.2 The plus–minus principle 235
6.2.3 Appropriate Placement applied to unit operations 237
6.3 Reactor systems 239
6.4 Distillation columns 241
6.4.1 Overview of basic analysis method 241
6.4.2 Refinements to the analysis 242
6.4.3 Multiple columns 243
6.4.4 Distillation column profiles 244
6.4.5 Distillation column sequencing 248
6.5 Other separation systems 252
6.5.1 Evaporator systems 252
6.5.2 Flash systems 260
6.5.3 Solids drying 263
6.5.4 Other separation methods 266
6.6 Application to the organics distillation process case study 266
6.6.1 Identifying potential process changes 266
6.6.2 Eliminating bottoms rundown: detailed analysis 268
6.6.3 Economic assessment 272
6.7 Summary and conclusions 274
Exercises 274
Chapter 7: Batch and time-dependent processes 276
7.1 Introduction 276
7.2 Concepts 278
7.3 Types of streams in batch processes 282
7.4 Time intervals 284
7.5 Calculating energy targets 284
7.5.1 Formation of stream data 285
7.5.2 Time average model 285
7.5.3 Time slice model 285
7.5.4 Heat storage possibilities 288
7.6 Heat exchanger network design 292
7.6.1 Networks based on continuous or averaged process 292
7.6.2 Networks based on individual time intervals 293
7.7 Rescheduling 296
7.7.1 Definition 296
7.7.2 Classification of rescheduling types 296
7.7.3 Methodology 298
7.8 Debottlenecking 300
7.9 Other time-dependent applications 304
7.9.1 Start-up and shutdown 304
7.9.2 Day/night variations 305
7.10 Conclusions 305
Chapter 8: Applying the technology in practice 308
8.1 Introduction 308
8.2 How to do a pinch study 308
8.3 Heat and mass balance 309
8.4 Stream data extraction 310
8.4.1 Mixing and splitting junctions 311
8.4.2 Effective process temperatures 313
8.4.3 Process steam and water 314
8.4.4 Soft data 315
8.4.5 Units 316
8.4.6 Worked example 317
8.5 Targeting and network design 320
8.5.1 Targeting 320
8.5.2 Network design 320
8.6 Targeting software 321
8.6.1 Options available 321
8.6.2 Spreadsheet accompanying this book 322
8.7 Industrial experience 322
8.7.1 Oil refining 325
8.7.2 Bulk chemicals – continuous 326
8.7.3 Speciality and batch chemicals and pharmaceuticals 326
8.7.4 Pulp and paper 327
8.7.5 Food and beverage 327
8.7.6 Consumer products and textiles 328
8.7.7 Minerals and metals 328
8.7.8 Heat and power utilities 329
8.7.9 Buildings 330
Exercises 330
Chapter 9: Case studies 332
9.1 Introduction 332
9.2 Crude preheat train 332
9.2.1 Process description 333
9.2.2 Data extraction and energy targeting 333
9.2.3 Pinch identification and network design 338
9.2.4 Design evolution 344
9.2.5 Design evaluation 348
9.2.6 Conclusions 349
9.3 Aromatics plant 349
9.3.1 Introduction 349
9.3.2 Process description 351
9.3.3 Stream data extraction 351
9.3.4 Energy targeting 355
9.3.5 Design of an MER network 357
9.3.6 Network design based on existing layout 363
9.3.7 Practical process design considerations 365
9.3.8 Further considerations 366
9.3.9 Targeting and design with alternative stream data 368
9.3.10 Conclusions 370
9.4 Evaporator/dryer plant 370
9.4.1 Process description 371
9.4.2 Stream data extraction 371
9.4.3 Energy targeting 375
9.4.4 Heat pumping strategy 375
9.4.5 Process change analysis 377
9.4.6 Selection of final scheme layout 380
9.4.7 Conclusions 384
9.5 Organic chemicals manufacturing site 385
9.5.1 Process description and targeting 385
9.5.2 Practical implementation 386
9.5.3 Conclusions 388
9.6 Hospital site 388
9.6.1 Site description and stream data extraction 388
9.6.2 Targeting using time intervals 390
9.6.3 Rescheduling possibilities 391
9.6.4 Process change possibilities 393
9.6.5 Opportunities for combined heat and power 394
9.6.6 Conclusions 395
9.7 Conclusions 396
Exercises 397
Chapter 10: Conclusions 398
Notation 400
Glossary of terms 402
A 402
B 402
C 402
D 402
E 402
F 402
G 402
H 403
I 403
L 403
M 403
N 403
O 404
P 404
R 404
S 404
T 404
U 405
Further reading 406
Appendix – using the spreadsheet software 408
Index 410
A 410
B 410
C 410
D 411
E 411
F 411
G 411
H 412
I 412
J 412
L 412
M 412
N 413
O 413
P 413
Q 413
R 413
S 414
T 414
U 415
V 415
W 415
Z 415