Ⅰ Introduction 1
Ⅰ.1 Separation processes 1
Ⅰ.2 Introduction to membrane processes 7
Ⅰ.3 History 9
Ⅰ.4 Definition of a membrane 12
Ⅰ.5 Membrane processes 14
Ⅰ.6 Solved problems 18
Ⅰ.7 Unsolved problems 19
Ⅰ.8 Literature 20
Ⅱ Materials and material properties 22
Ⅱ.1 Introduction 22
Ⅱ.2 Polymers 22
Ⅱ.3 Stereoisomerism 24
Ⅱ.4 Chain flexibility 26
Ⅱ.5 Molecular weight 27
Ⅱ.6 Chain interactions 29
Ⅱ.7 State of the polymer 31
Ⅱ.8 Effect of polymeric structure on Tg 33
Ⅱ.9 Glass transition temperature depression 40
Ⅱ.10 Thermal and chemical stability 41
Ⅱ.11 Mechanical properties 44
Ⅱ.12 Elastomers 45
Ⅱ.13 Thermoplastic elastomers 47
Ⅱ.14 Polyelectrolytes 47
Ⅱ.15 Polymer blends 49
Ⅱ.16 Membrane polymers 51
Ⅱ.16.1 Porous membranes 52
Ⅱ.16.2 Nonporous membranes 59
Ⅱ.17 Inorganic membranes 60
Ⅱ.17.1 Thermal stability 60
Ⅱ.17.2 Chemical stabili 61
Ⅱ.17.3 Mechanical stabili 61
Ⅱ.18 Biological membranes 62
Ⅱ.18.1 Synthetic biological membranes 66
Ⅱ.19 Solved problems 67
Ⅱ.20 Unsolved problems 67
Ⅱ.21 Literature 69
Ⅲ Preparation of synthetic membranes 71
Ⅲ.1 Introduction 71
Ⅲ.2 Preparation of synthetic membranes 72
Ⅲ.3 Phase inversion membranes 75
Ⅲ.3.1 Preparation by evaporation 76
Ⅲ.3.2 Precipitation from the vapour phase 76
Ⅲ.3.3 Precipitation by controlled evaporation 76
Ⅲ.3.4 Thermal precipitation 76
Ⅲ.3.5 Immersion precipitation 77
Ⅲ.4 Preparation techniques for immersion precipitation 77
Ⅲ.4.1 Flat membranes 77
Ⅲ.4.2 Tubular membranes 78
Ⅲ.5 Preparation techniques for composite membranes 81
Ⅲ.5.1 Interfacial polymerisation 82
Ⅲ.5.2 Dip-coating 83
Ⅲ.5.3 Plasma polymerisation 86
Ⅲ.5.4 Modification of homogeneous dense membranes 87
Ⅲ.6 Phase separation in polymer systems 89
Ⅲ.6.1 Introduction 89
Ⅲ.6.1.1 Thermodynamics 89
Ⅲ.6.2 Demixing processes 99
Ⅲ.6.2.1 Binary mixtures 99
Ⅲ.6.2.2 Ternary systems 102
Ⅲ.6.3 Crystallisation 104
Ⅲ.6.4 Gelation 106
Ⅲ.6.5 Vitrification 108
Ⅲ.6.6 Thermal precipitation 109
Ⅲ.6.7 Immersion precipitation 110
Ⅲ.6.8 Diffusional aspects 114
Ⅲ.6.9 Mechanism of membrane formation 117
Ⅲ.7 Influence of various parameters on membrane morphology 123
Ⅲ.7.1 Choice of solvent-nonsolvent system 123
Ⅲ.7.2 Choice of the polymer 129
Ⅲ.7.3 Polymer concentration 130
Ⅲ.7.4 Composition of the coagulation bath 132
Ⅲ.7.5 Composition of the casting solution 133
Ⅲ.7.6 Preparation of porous membranes - summary 134
Ⅲ.7.7 Formation of integrally skinned membranes 135
Ⅲ.7.7.1 Dry-wet phase separation process 136
Ⅲ.7.7.2 Wet-phase separation process 137
Ⅲ.7.8 Formation of macrovoids 138
Ⅲ.8 Inorganic membranes 141
Ⅲ.8.1 The sol-gel process 141
Ⅲ.8.2 Membrane modification 144
Ⅲ.8.3 Zeolite membranes 144
Ⅲ.8.4 Glass membranes 146
Ⅲ.8.5 Dense membranes 147
Ⅲ.9 Solved problems 147
Ⅲ.10 Unsolved problems 147
Ⅲ.11 Literature 154
Ⅳ Characterisation of membranes 157
Ⅳ.1 Introduction 157
Ⅳ.2 Membrane characterisation 158
Ⅳ.3 Characterisation of porous membranes 160
Ⅳ.3.1 Microfiiltration 162
Ⅳ.3.1.1 Electron microscopy 162
Ⅳ.3.1.2 Atomic force microscopy 164
Ⅳ.3.1.3 Bubble-point method 165
Ⅳ.3.1.4 Bubble-point with gas permeation 167
Ⅳ.3.1.5 Mercury intrusion method 168
Ⅳ.3.1.6 Permeability method 169
Ⅳ.3.2 Ultrafiltration 172
Ⅳ.3.2.1. Gas adsorption-desorption 173
Ⅳ.3.2.2 Thermoporometry 176
Ⅳ.3.2.3 Permporometry 179
Ⅳ.3.2.4 Liquid displacement 181
Ⅳ.3.2.5 Solute rejection measurements 183
Ⅳ.4 Characterisation of ionic membranes 188
Ⅳ.4.1 Electrokinetic phenomena 189
Ⅳ.4.2 Electro-osmosis 192
Ⅳ.5 Characterisation of nonporous membranes 192
Ⅳ.5.1 Permeability methods 194
Ⅳ.5.2 Physical methods 195
Ⅳ.5.2.1 DCS/DTA methods 195
Ⅳ.5.2.2 Density measurements 197
Ⅳ.5.2.2.1 Density gradient column 197
Ⅳ.5.2.2.2 Densical determination by the Archimedes principle 198
Ⅳ.5.2.3 Wide-angle X-ray diffraction （WAXD） 198
Ⅳ.5.3 Plasma etching 199
Ⅳ.5.4 Surface analysis methods 201
Ⅳ.6 Solved problems 204
Ⅳ.7 Unsolved problems 204
Ⅳ.8 Literature 208
Ⅴ Transport in membranes 210
Ⅴ.1 Introduction 210
Ⅴ.2 Driving forces 212
Ⅴ.3 Nonequilibrium thermodynamics 214
Ⅴ.4 Transport through porous membranes 224
Ⅴ.4.1 Transport of gases through porous membranes 225
Ⅴ.4.1.1 Knudsen flow 226
Ⅴ.4.2 Friction model 228
Ⅴ.5 Transport through nonporous membranes 232
Ⅴ.5.1 Transport in ideal systems 239
Ⅴ.5.1.1 Determination of the diffusion coefficient 243
Ⅴ.5.1.2 Determination of the solubility coefficient 244
Ⅴ.5.1.3 Effect of temperature on the permeability coeffiicient 246
Ⅴ.5.2 Interactive systems 248
Ⅴ.5.2.1 Free volume theory 251
Ⅴ.5.2.2 Clustering 254
Ⅴ.5.2.3 Solubility of liquid mixtures 255
Ⅴ.5.2.4 Transport of single liquids 257
Ⅴ.5.2.5 Transport of liquid mixtures 258
Ⅴ.5.3 Effect of crystallinity 259
Ⅴ.6 Transport through membranes.A unified approach 260
Ⅴ.6.1 Reverse osmosis 264
Ⅴ.6.2 Dialysis 266
Ⅴ.6.3 Gas permeation 266
Ⅴ.6.4 Pervaporation 267
Ⅴ.7 Transport in ion-exchange membranes 267
Ⅴ.8 Solved problems 271
Ⅴ.9 Unsolved problems 272
Ⅴ.8 Literature 278
Ⅵ Membrane processes 280
Ⅵ.1 Introduction 280
Ⅵ.2 Osmosis 282
Ⅵ.3 Pressure driven membrane processes 284
Ⅵ.3.1 Introduction 284
Ⅵ.3.2 Microfiltration 286
Ⅵ.3.2.1 Membranes for microfiltration 288
Ⅵ.3.2.2 Industrial applications 292
Ⅵ.3.2.3 Summary of microfiltration 292
Ⅵ.3.3 Ultrafiltration 293
Ⅵ.3.3.1 Membranes for ultrafiltration 294
Ⅵ.3.3.2 Applications 295
Ⅵ.3.3.3 Summary of ultrafiltration 296
Ⅵ.3.4 Reverse osmosis and nanofiiltration 297
Ⅵ.3.4.1 Membranes for reverse osmosis and nanofiltration 299
Ⅵ.3.4.2 Applications 301
Ⅵ.3.4.3 Summary of nanofiltration 302
Ⅵ.3.4.3 Summary of reverse osmosis 303
Ⅵ.3.5 Pressure retarded osmosis 303
Ⅵ.3.5.1 Summary of pressure retarded osmosis 305
Ⅵ.3.6 Piezodialysis 305
Ⅵ.3.6.1 Summary of piezodialysis 306
Ⅵ.4 Concentration as driving force 307
Ⅵ.4.1 Introduction 307
Ⅵ.4.2 Gas separation 308
Ⅵ.4.2 Gas separation 308
Ⅵ.4.2.1 Gas separation in porous membranes 308
Ⅵ.4.2.2 Gas separation in nonporous membranes 309
Ⅵ.4.2.3 Aspects of separation 311
Ⅵ.4.2.4 Joule - Thomson effect 317
Ⅵ.4.2.5 Membranes for gas separation 319
Ⅵ.4.2.6 Applications 323
Ⅵ.4.2.7 Summary of gas separation 324
Ⅵ.4.3 Pervaporation 325
Ⅵ.4.3.1 Aspects of separation 327
Ⅵ.4.3.2 Membranes for pervaporation 333
Ⅵ.4.3.3 Applications 336
Ⅵ.4.3.4 Summary of pervaporation 339
Ⅵ.4.4 Carrier mediated transport 339
Ⅵ.4.4.1 Liquid membranes 340
Ⅵ.4.4.2 Aspects of separation 347
Ⅵ.4.4.3 Liquid membrane development 352
Ⅵ.4.4.4 Choice of the organic solvent 353
Ⅵ.4.4.5 Choice of the carrier 355
Ⅵ.4.4.6 Applications 357
Ⅵ.4.4.7 Summary of carrier mediated transport 357
Ⅵ.4.5 Dialysis 358
Ⅵ.4.5.1 Transport 359
Ⅵ.4.5.2 Membranes 360
Ⅵ.4.5.3 Applications 360
Ⅵ.4.5.4 Summary of dialysis 361
Ⅵ.4.6 Diffusion dialysis 361
Ⅵ.4.6.1 Applications 363
Ⅵ.4.6.2 Summary of diffusion dialysis 364
Ⅵ.5 Thermally driven membrane processes 364
Ⅵ.5.1 Introduction 364
Ⅵ.5.2 Membrane distillation 365
Ⅵ.5.2.1 Process parameters 367
Ⅵ.5.2.2 Membranes 370
Ⅵ.5.2.3 Applications 370
Ⅵ.5.2.4 Summary of membrane distillation 373
Ⅵ.6 Membrane contactors 373
Ⅵ.6.1 Gas-liquid contactor 375
Ⅵ.6.1.1 Introduction 375
Ⅵ.6.2 Liquid-liquid contactors 377
Ⅵ.6.2.1 Introduction 377
Ⅵ.6.3 Nonporous membrane contactors 378
Ⅵ.6.4 Summary of membrane contactors 379
Ⅵ.6.5 Thermo-osmosis 380
Ⅵ.7 Electrically driven membrane processes 380
Ⅵ.7.1 Introduction 380
Ⅵ.7.2 Electrodialysis 380
Ⅵ.7.2.1 Process parameters 382
Ⅵ.7.2.2 Membranes for electrodialysis 385
Ⅵ.7.2.3 Applications 387
Ⅵ.7.2.3.1 Separation of amino acids 387
Ⅵ.7.2.4 Summary of electrodialysis 388
Ⅵ.7.3 Membrane electrolysis 388
Ⅵ.7.3.1 The ’chlor-alkali’ process 389
Ⅵ.7.3.2 Bipolar membranes 390
Ⅵ.7.4 Fuel cells 391
Ⅵ.7.5 Electrolytic regeneration of mixed-bed ion-exchange resin 393
Ⅵ.8 Membrane reactors and membrane bioreactors 394
Ⅵ.8.1 Membrane reactors 395
Ⅵ.8.2 Non-selective membrane reactor 396
Ⅵ.8.3 Membrane reactor in liquid phase reactions 398
Ⅵ.8.4 Membrane bioreactors 400
Ⅵ.9 Solved problems 400
Ⅵ.10 Unsolved problems 402
Ⅵ.11 Literature 412
Ⅶ Polarisation phenomena and fouling 416
Ⅶ.1 Introduction 416
Ⅶ.2 Concentration polarisation 418
Ⅶ.2.1 Concentration profiles 423
Ⅶ.3 Turbulence promoters 424
Ⅶ.4 Pressure drop 426
Ⅶ.5 Characteristic flux behaviour in pressure driven membrane operations 427
Ⅶ.6 Gel layer model 429
Ⅶ.7 Osmotic pressure model 431
Ⅶ.8 Boundary layer resistance model 436
Ⅶ.9 Concentration polarisation in diffusive membrane separations 440
Ⅶ.10 Concentration polarisation in electrodialysis 442
Ⅶ.11 Temperature polarisation 444
Ⅶ.12 Membrane fouling 447
Ⅶ.12.1 Fouling tests in reverse osmosis 451
Ⅶ.13 Methods to reduce fouling 453
Ⅶ.14 Compaction 456
Ⅶ.15 Solved problems 456
Ⅶ.16 Unsolved problems 457
Ⅶ.17 Literature 463
Ⅷ Module and process design 465
Ⅷ.1 Introduction 465
Ⅷ.2 Plate-and-frame model 466
Ⅷ.3 Spiral wound module 468
Ⅷ.4 Tubular module 469
Ⅷ.5 Capillary module 470
Ⅷ.6 Hollow fiber module 472
Ⅷ.7 Comparison of the module configurations 473
Ⅷ.8 System design 474
Ⅷ.9 Cross-flow operations 475
Ⅷ.10 Hybrid dead-end/cross flow system 478
Ⅷ.11 Cascade operations 479
Ⅷ.12 Some examples of system design 480
Ⅷ.12.1 Ultrapure water 481
Ⅷ.12.2 Recovery of organic vapours 482
Ⅷ.12.3 Desalination of seawater 483
Ⅷ.12.4 Dehydration of ethanol 484
Ⅷ.12.5 Economics 485
Ⅷ.13 Process parameters 486
Ⅷ.14 Reverse osmosis 487
Ⅷ.15 Diafiltration 491
Ⅷ.16 Gas separation and vapour permeation 493
Ⅷ.16.1 Gas separation under complete mixing conditions 494
Ⅷ.16.2 Gas separation under cross-flow conditions 496
Ⅷ.17 Pervaporation 498
Ⅷ.17.1 Complete mixing in pervaporation 498
Ⅷ.17.2 Cross-flow in pervaporation 500
Ⅷ.18 Pervaporation 501
Ⅷ.19 Dialysis 503
Ⅷ.20 Energy requirements 505
Ⅷ.20.1 Pressure driven processes 506
Ⅷ.20.2 Partial pressure driven processes 507
Ⅷ.20.3 Concentration driven processes 508
Ⅷ.21 Solved problems 509
Ⅷ.22 Unsolved problems 511
Ⅷ.23 Literature 519
Appendix 1 522
Appendix 2 523
Answers to exercises： solved problems 525
Answers to exercises： unsolved problems 547
List of symbols 553
Index 557