Membranes for Energy Applications

Complete learning resource to understand membrane technology for gas, ion, and water transportation and/or separation

This book provides important information on membranes for energy production as well as the recent key advances that have been made in the field. It benefits the reader not only by providing insight into the application of membranes in the energy industry, but also by explaining the principles or theories behind this important application, including the transport of small molecules such as gas, ion, and water.

Contributed by a world-renowned and long-standing expert in the field of membrane materials and processes, the book covers many important areas of interest, such as:

• The history of membrane science and technology
• Fundamentals of membrane technology, including principles of membrane formation and principle behind
• Gas separation using membrane technology
• Membranes for ion transport or separation realized in energy generation and storage
• The future direction and outlook of membrane technology in energy application and industry

This book is a must-have resource for professionals in the field who wish to gain mastery over the topic of membranes and how they relate to energy application. Many different types of scientists and engineers will be able to derive immense value from its comprehensive yet concise approach.

Preface xi

Acknowledgments xiii

1 Introduction 1

1.1 Energy and Membranes 1

1.2 Brief History of Membrane Technology 3

1.2.1 Current State-of-the-Art Membrane Technology 5

References 6

2 Fundamentals of Membrane Technology 9

2.1 Introduction 9

2.2 Definition of Terms 9

2.2.1 The Membrane and Its Function 9

2.2.2 Membrane Materials and Structure 10

2.2.2.1 Symmetric and Asymmetric Membranes 11

2.2.2.2 Porous Membranes 12

2.2.2.3 Homogeneous Dense Membranes 12

2.2.2.4 Ion Exchange Membranes 13

2.2.2.5 Membrane Shapes 13

2.2.3 Mass Transport in Membranes 14

2.2.4 Separation Properties 16

2.3 Membrane Materials 17

2.3.1 Polymer Materials 18

2.3.1.1 Physical State and Properties of Polymer 19

2.3.2 Inorganic Materials 20

2.3.2.1 Preparation of Ceramic Membranes 21

2.4 Basic Principles of Membrane Preparation 22

2.4.1 Thermodynamics of Phase Separation 22

2.4.2 Nonsolvent-induced Phase Separation 25

2.4.2.1 Type of Polymer 26

2.4.2.2 Polymer Concentration 26

2.4.2.3 Additives 26

2.4.2.4 Casting Temperature 26

2.4.3 Thermally Induced Phase Separation 27

2.4.3.1 Polymer–Solvent Interaction 28

2.4.3.2 Effect of Cooling Rate 29

2.4.3.3 Effect of Additives 29

2.5 Membrane Fabrication 29

2.5.1 Asymmetric Membranes 29

2.5.2 Flat Sheet Membranes 33

2.5.3 Thin-Film Composite Membranes 34

2.6 Membrane Module Fabrication 34

References 37

3 Membranes in Gas Separation for Energy and Environment 39

3.1 Introduction 39

3.2 Basic Principles of Gas Separation in Polymer Membranes 41

3.2.1 Permeability and Selectivity 41

3.2.2 Temperature Dependence of Gas Transport 44

3.2.3 Pressure Dependence of Gas Transport 45

3.2.4 Unusual Sorption Behavior of Glassy Polymers 46

3.2.5 Criteria for Membrane Material Selection 48

3.2.5.1 Diffusivity-Selective Polymer Membranes 48

3.2.5.2 Solubility-Selective Membrane 49

3.3 Limitations of Gas Separations Using Polymer Membranes 52

3.4 Polymer Membrane Materials 55

3.4.1 Cellulose Acetate 55

3.4.2 Polysulfone 57

3.4.3 Polyimides 58

3.4.4 Siloxane Polymers 59

3.4.5 Substituted Polyacetylenes 61

3.4.6 Amorphous Fluoropolymers 64

3.4.7 Polybenzimidazole 66

3.4.8 Nanocomposites and Mixed Matrix Membranes 68

3.4.9 Other Promising Polymers 74

3.4.9.1 Pebax 74

3.4.9.2 Polymers with Intrinsic Microporosity 75

3.4.9.3 Thermally Rearranged (TR) Polymer Membranes 81

3.4.9.4 High-performance Polyimides 86

3.5 Membrane Gas Separation Applications 89

3.5.1 Air Separation 89

3.5.2 Hydrogen Separation 94

3.5.3 Hydrocarbon/Hydrocarbon Separation 97

3.5.4 Carbon Dioxide Separation 101

3.5.4.1 Post-combustion Flue Gas CO₂ Capture 102

3.5.4.2 CO₂ Removal from Natural Gas 109

3.5.4.3 CO₂ Recovery from Biogas 110

3.5.5 Vapor/Gas Separation 112

3.6 Conclusions and Future Perspectives 113

References 113

4 Membranes for Fuel Cell 135

4.1 Introduction 135

4.1.1 Fuel Cells as Electrochemical Engines 138

4.1.2 Classification of Fuel Cells 140

4.1.3 History of Fuel Cell Development 141

4.2 Basic Electrochemical Principles 143

4.2.1 Electrochemical Reactions 143

4.2.2 Basic Principles of Fuel Cells 145

4.2.3 Voltage Losses 151

4.2.3.1 Activation Losses 151

4.2.3.2 Fuel Crossover and Internal Currents 153

4.2.3.3 Ohmic Losses 153

4.2.3.4 Mass Transport and Concentration Losses 154

4.2.4 Water Management 156

4.3 Membranes in Proton Exchange Membrane Fuel Cell 157

4.3.1 Perfluorosulfonic Acids 158

4.3.2 Characteristics of Nafion 159

4.3.3 Degradation of Nafion 162

4.3.4 Composite PEM 163

4.3.5 Radiation-Grafted Fluoropolymer PEM 163

4.3.6 Hydrocarbon-Based Cation Exchange Membranes 168

4.3.7 Fuel Cell Stacks-MEA 177

4.4 Membranes in Direct Methanol Fuel Cell 177

4.5 Membranes in Anion Exchange Membrane Fuel Cell 180

4.5.1 Ammonium Groups and Their Stability 182

4.5.2 Stable Polymer Backbones 187

4.5.2.1 Aryl-Ether Polymers 187

4.5.2.2 Polybenzimidazole and SEBS 188

4.5.2.3 Poly(norbonene) 189

4.5.2.4 Diels-Alder Polymer – Polyphenylene 190

4.5.2.5 Poly(aryl piperidinium)s 191

4.5.2.6 Radiation-Grafted AEM 193

4.5.3 Water Management 198

4.5.4 Outlook 198

4.6 Anion Exchange Ionomers 199

4.7 Fuel Cell Vehicle Market 202

4.8 Conclusions and Future Perspectives 204

References 205

5 Membranes in Energy Storage System 217

5.1 Introduction 217

5.1.1 Li-Ion Battery 217

5.1.1.1 Battery Market, Separator Market 218

5.2 Requirements of Li-Ion Battery Separators 222

5.3 Fabrication of Separator 226

5.3.1 Type of Polymers 226

5.3.2 Type and Fabrication of Separator 226

5.3.2.1 Type of Separator 226

5.3.2.2 Fabrication of Separator 227

5.4 Gel Polymer Electrolytes 233

5.5 Polymers for Separators and Polymer Electrolytes 234

5.5.1 Polyolefin 234

5.5.2 PVDF 234

5.5.3 Poly(vinylidene fluoride-hexafluoro propylene) 238

5.6 Next-Generation Li Battery 239

5.6.1 Li-Air Battery Separator 241

5.6.2 Li-S Battery Separator 242

5.6.3 All Solid-State Li-Ion Battery 243

5.7 Conclusions and Future Perspectives 247

References 248

6 Membranes in Hydrogen Production by Water Electrolysis 257

6.1 Introduction 257

6.2 Alkaline Water Electrolysis 261

6.2.1 History of Water Electrolysis 261

6.2.2 Alkaline Electrolysis 263

6.2.3 Major Issues 263

6.3 Proton Exchange Membrane Water Electrolysis 264

6.3.1 Advantages of PEMWE 266

6.3.2 Disadvantages of PEMWE 266

6.3.3 Membranes 267

6.3.4 Ionomers 271

6.3.5 Technical Achievements and Applications 273

6.4 Alkaline Exchange Membrane Water Electrolysis 274

6.4.1 Difference Between AWE and AEMWE 276

6.4.2 Liquid Electrolytes 276

6.4.3 Anion Exchange Membranes 277

6.4.3.1 Commercial Membranes 278

6.4.3.2 Chemical Stability of Cationic Groups 290

6.4.4 Ionomers 293

6.4.5 Durability 294

6.4.6 Outlook for AEMWE 296

6.5 Conclusions and Future Perspectives 298

References 298

7 Membranes for Power Generation 309

7.1 Water Energy Nexus and Membranes 309

7.2 Concept of Osmotic Power 311

7.3 Energy Obtained from PRO 314

7.4 Membranes for Pressure-Retarded Osmosis 317

7.4.1 Cellulose Triacetate Membrane 318

7.4.2 Thin-Film Composite Membrane 318

7.4.3 Importance of Support Membranes 319

7.4.4 Sponge-like Porous Structure of Support 320

7.4.5 Nanofibrous Support Membrane 321

7.4.6 Selective Layer 321

7.5 Hybrid Systems with Membrane Distillation and Others 324

7.5.1 PRO-MD Hybrid System 324

7.5.2 SWRO-PRO Hybrid System 325

7.5.3 SWRO-PRO-MD Trihybrid System 327

7.5.4 Osmotic Heat Engine System 327

7.6 Conclusions and Future Perspectives 328

References 329

Index 335

Young Moo Lee is currently Distinguished Professor of Energy Engineering at Hanyang University, Seoul, South Korea. He served as the 14th President of Hanyang University from 2015 to 2019. He is engaged in novel membrane materials and processes for gas and vapor separation including thermally rearranged polymer membranes, organic–inorganic hybrid membranes, surface modified membranes, and the design of novel polymers for fuel cells. Professor Lee has received numerous awards such as Top 100 Research Award by Korea Research Foundation (2017), Kyung Am Award (2012), and Top 50 Research Award by Korea Science and Engineering Foundation (2008).