Preface xi
Acknowledgments xiii
1 Overview of Membrane Science and Technology 1
1.1 Introduction 2
1.2 Historical Development of Membranes 2
1.3 Membrane Transport Theory 4
1.4 Types of Membranes 6
1.4.1 Isotropic Membranes 8
1.4.2 Anisotropic Membranes 8
1.4.3 Membranes with Special Features 9
1.5 Membrane Processes 9
1.5.1 Reverse Osmosis, Ultrafiltration, Microfiltration 10
1.5.2 Electrodialysis 11
1.5.3 Gas Separation 12
1.5.4 Pervaporation 13
1.5.5 Hyperfiltration 14
1.5.6 Membrane Contactors 14
1.5.7 Carrier Transport 15
1.5.8 Medical Applications 16
References 17
2 Membrane Transport Theory - Solution-Diffusion 18
2.1 Introduction 18
2.2 The Solution-Diffusion Model 21
2.2.1 Molecular Dynamics Simulations 21
2.2.2 Concentration and Pressure Gradients in Membranes 25
2.2.3 Application of the Solution-Diffusion Model to Specific Processes 31
2.2.4 A Unified View 52
2.3 Structure-Permeability Relationships in Solution-Diffusion Membranes 56
2.3.1 Diffusion Coefficients 59
2.3.2 Sorption Coefficients in Polymers 68
2.4 Conclusions 74
References 75
3 Microporous Membranes - Characteristics and Transport Mechanisms 79
3.1 Introduction 80
3.2 Gas Separation in Microporous Membranes 81
3.2.1 Membrane Categories 81
3.2.2 Crystalline Finely Microporous Membranes 82
3.2.3 Amorphous Microporous Membranes 90
3.3 Gas Separation: Transport Mechanisms 95
3.3.1 Surface Adsorption and Diffusion 95
3.3.2 Knudsen Diffusion 98
3.3.3 Molecular Sieving 100
3.3.4 Pore Blocking 101
3.3.5 Summary 104
3.4 Liquid Permeation in Microporous Membranes 105
3.4.1 Screen Filters 105
3.4.2 Depth Filters 109
3.5 Conclusions and Future Directions 110
References 111
4 Membranes and Modules 115
4.1 Introduction 116
4.2 Isotropic Membranes 116
4.2.1 Isotropic Nonporous Membranes 116
4.2.2 Isotropic Microporous Membranes 118
4.3 Anisotropic Membranes 122
4.3.1 Phase Separation Membranes 123
4.3.2 Interfacial Polymerization Membranes 138
4.3.3 Solution-Coated Composite Membranes 143
4.3.4 Repairing Membrane Defects 147
4.4 Ceramic and Glass Membranes 149
4.4.1 Ceramic Membranes 149
4.4.2 Microporous Glass Membranes 152
4.5 Other Membranes 152
4.6 Hollow Fiber Membranes 153
4.7 Membrane Modules 156
4.7.1 Plate-and-Frame Modules 158
4.7.2 Tubular Modules 159
4.7.3 Spiral-Wound Modules 162
4.7.4 Hollow Fiber Modules 165
4.7.5 Other Module Types 167
4.8 Module Selection 168
4.9 Conclusions and Future Directions 170
References 171
5 Concentration Polarization 177
5.1 Introduction 177
5.2 Boundary Layer Film Model 180
5.2.1 Determination of the Peclet Number 187
5.3 Concentration Polarization in Liquid Separation Processes 189
5.4 Concentration Polarization in Gas Separation Processes 193
5.5 Concentration Polarization in Membrane Contactors and Related Processes 194
5.6 Conclusions and Future Directions 196
References 196
6 Reverse Osmosis (Hyperfiltration) 198
6.1 Introduction and History 199
6.2 Theoretical Background 201
6.3 Membrane Materials 204
6.3.1 Cellulosic Membranes 204
6.3.2 Noncellulosic Loeb-Sourirajan Membranes 206
6.3.3 Interfacial Composite Membranes 207
6.4 Membrane Performance 210
6.5 Reverse Osmosis Membrane Categories 211
6.5.1 Seawater Desalination Membranes 211
6.5.2 Brackish Water Desalination Membranes 213
6.5.3 Nanofiltration Membranes 213
6.5.4 Organic Solvent Separating Membranes 215
6.6 Membrane Modules 218
6.7 Membrane Fouling and Control 219
6.7.1 Silt 220
6.7.2 Scale 220
6.7.3 Biofouling 223
6.7.4 Organic Fouling 223
6.7.5 Pretreatment 223
6.7.6 Membrane Cleaning 224
6.8 Applications 225
6.8.1 Seawater Desalination 226
6.8.2 Brackish Water Desalination 228
6.8.3 Industrial Applications 229
6.8.4 Organic Solvent Separations 232
6.8.5 Conclusions and Future Directions 236
References 238
7 Ultrafiltration 241
7.1 Introduction and History 242
7.2 Characterization of Ultrafiltration Membranes 244
7.3 Membrane Fouling 246
7.3.1 Constant Pressure and Constant Flux Operation 246
7.3.2 Concentration Polarization 251
7.3.3 Fouling Control 259
7.4 Membranes 260
7.5 Tangential-Flow Modules and Process Designs 261
7.5.1 Modules 262
7.5.2 Process Design 264
7.6 Applications 266
7.6.1 Industrial Applications 268
7.6.2 Municipal Water Treatment/Membrane Bioreactors (MBRs) 274
7.6.3 Biotechnology 280
7.7 Conclusions and Future Directions 282
References 284
8 Microfiltration 287
8.1 Introduction and History 287
8.2 Background 288
8.2.1 Types of Membrane 288
8.2.2 Membrane Characterization 291
8.2.3 Microfiltration Membranes and Modules 297
8.2.4 Process Design 300
8.3 Applications 301
8.3.1 Sterile Filtration of Pharmaceuticals 302
8.3.2 Microfiltration in the Electronics Industry 303
8.3.3 Sterilization of Wine and Beer 304
8.4 Conclusions and Future Directions 304
References 304
9 Gas Separation 305
9.1 Introduction and History 306
9.2 Dense Polymeric Membranes 308
9.2.1 Theoretical Background 308
9.2.2 Structural Features and Considerations 315
9.3 Microporous Membranes 317
9.4 Membrane Modules 319
9.5 Process Design 320
9.5.1 Pressure Ratio 321
9.5.2 Stage-Cut 325
9.5.3 Multistep and Multistage System Designs 327
9.5.4 Recycle Designs 329
9.6 Applications 330
9.6.1 Hydrogen Separation 330
9.6.2 Air Separation 333
9.6.3 Natural Gas Separations 338
9.6.4 Organic Vapor/Gas Separations 347
9.6.5 To-Be-Developed Applications 348
9.7 Conclusions and Future Directions 353
References 355
10 Pervaporation/Vapor Permeation 359
10.1 Introduction and History 359
10.2 Theoretical Background 362
10.3 Membrane Materials and Modules 370
10.3.1 Membrane Characterization 370
10.3.2 Membrane Materials 370
10.3.3 Membrane Modules 375
10.4 Process Design 377
10.4.1 Basic Principles 377
10.4.2 Hybrid Distillation/Membrane Processes 380
10.5 Applications 382
10.5.1 Bioethanol and Solvent Dehydration 383
10.5.2 VOC/Water Separations 384
10.5.3 Separation of Organic Mixtures 385
10.6 Conclusions and Future Directions 390
References 390
11 Ion Exchange Membrane Processes 394
11.1 Introduction and History 395
11.2 Theoretical Background 396
11.2.1 Transport Through Ion Exchange Membranes 397
11.3 Chemistry of Ion Exchange Membranes 400
11.3.1 Homogeneous Membranes 402
11.3.2 Heterogeneous Membranes 404
11.4 Electrodialysis 405
11.4.1 Concentration Polarization and Limiting Current Density 405
11.4.2 Current Efficiency and Power Consumption 410
11.4.3 System Design 411
11.5 Electrodialysis Applications 414
11.5.1 Water Desalination 414
11.5.2 Continuous Electrodeionization and Ultrapure Water 414
11.5.3 Salt Recovery from Seawater 416
11.5.4 Other Electrodialysis Applications 416
11.6 Fuel Cells 417
11.7 Chlor-Alkali Processes 421
11.8 Other Electrochemical Processes 423
11.8.1 Water Splitting Using Bipolar Membranes 423
11.8.2 Redox Flow Batteries 424
11.8.3 Reverse Electrodialysis 427
11.9 Conclusions and Future Directions 428
References 428
12 Carrier Facilitated Transport 431
12.1 Introduction 431
12.2 Facilitated Transport 435
12.2.1 Membrane and Process Development 435
12.2.2 Theory 437
12.2.3 Membranes 440
12.2.4 Applications 442
12.3 Coupled Transport 446
12.3.1 Membrane and Process Development 446
12.3.2 Theory 451
12.3.3 Coupled Transport Membrane Characteristics 454
12.3.4 Applications 459
12.4 Conclusions and Future Directions 459
References 460
13 Membrane Contactors 464
13.1 Introduction 464
13.2 Contactor Modules 466
13.3 Applications of Membrane Contactors 468
13.3.1 Liquid/Liquid Contactor Applications 469
13.3.2 Liquid/Gas and Gas/Liquid Contactors 478
13.3.3 Gas/Gas Membrane Contactors 482
13.4 Conclusions and Future Directions 486
References 486
14 Medical Applications of Membranes 490
14.1 Introduction 490
14.2 Hemodialysis 491
14.3 Plasma Fractionation 495
14.4 Blood Oxygenators 496
14.5 Controlled Drug Delivery 497
14.5.1 Membrane Diffusion-Controlled Systems 499
14.5.2 Monolithic Systems 502
14.5.3 Biodegradable Systems 502
14.5.4 Osmotic Systems 503
References 509
15 Other Membrane Processes 512
15.1 Introduction 512
15.2 Metal Membranes 512
15.3 Ion-Conducting Membranes 516
15.4 Charge Mosaic Membranes and Piezodialysis 520
References 523
Appendix 525
Index 536
