Introduction to Membrane Science and Technology

Heinrich Strathmann is Professor Emeritus of the University of Twente, The Netherlands. He obtained his basic education in Physical Chemistry at the University of Darmstadt in Germany where he received his Dr.-Ing. in 1965. He worked for several years in the membrane based industry in the United States and in Germany. He is also Associate Professor at the University of Stuttgart and Honorary Prrofessor at South China Central University.Dr. Strathmann is on the editorial board of various scientific journals and is author of three books on membrane science and technology. In 2007 he was awarded by the European Membrane Society with the R.M. Barrer Price.

• Preface xiiiSymbols xv1 Introduction 11.1 Overview of Membrane Science and Technology 11.2 History of Membrane Science and Technology 41.3 Advantages and Limitations of Membrane Processes 71.4 The Membrane-Based Industry: Its Structure and Markets 91.5 Future Developments in Membrane Science and Technology 121.5.1 Biological Membranes 141.6 Summary 16Recommended Reading 16References 172 Fundamentals 192.1 Introduction 192.2 Definition of Terms 192.2.1 The Membrane and Its Function 192.2.2 Membrane Materials and Membrane Structures 212.2.2.1 Symmetric and Asymmetric Membranes 222.2.2.2 Porous Membranes 232.2.2.3 Homogeneous Dense Membranes 232.2.2.4 Ion-Exchange Membranes 242.2.2.5 Liquid Membranes 242.2.2.6 Fixed Carrier Membranes 242.2.2.7 Other Membranes 252.2.2.8 Membrane Geometries 252.2.3 Mass Transport in Membranes 272.2.4 Membrane Separation Properties 312.2.5 Definition of Various Membrane Processes 332.2.5.1 Pressure-Driven Membrane Processes 342.2.5.2 Activity and Concentration Gradient Driven Membrane Processes 352.2.5.3 Electrical Potential and Electrochemical Potential Driven Processes 362.3 Fundamentals of Mass Transport in Membranes and Membrane Processes 372.3.1 Basic Thermodynamic Relationships with Relevance to Membrane Processes 372.3.2 Basic Electrochemical Relationships with Relevance to Membrane Processes 422.3.2.1 Electron and Ion Conductivity and Ohm’s Law 422.3.2.2 Ion Conductivity, Ion Mobility, and Drift Speed 432.3.2.3 Coulomb’s Law and the Electric Field Effect on Ions in Solution 452.3.2.4 The Electric Field Effect in Electrolyte Solutions and the Debye-Hückel Theory 462.3.2.5 Electrical Dipoles and Intermolecular Forces 482.3.3 Chemical and Electrochemical Equilibrium in Membrane Systems 492.3.3.1 Water Dissociation Equilibrium and the pH- and pK Values of Acids and Bases 492.3.3.2 Osmotic Equilibrium, Osmotic Pressure, Osmosis, and Reverse Osmosis 512.3.3.3 The Electrochemical Equilibrium and the Donnan Potential between a Membrane and a Solution 542.3.3.4 The Donnan Exclusion of the Co-ions 552.3.4 Fluxes and Driving Forces in Membrane Processes 572.3.4.1 Viscous Flow through Porous Membranes 582.3.4.2 Diffusion in Liquids and Dense Membranes 592.3.4.3 Diffusion in Solid or Dense Materials 632.3.4.4 Ion Flux and Electrical Current 652.3.4.5 Diffusion of Ions in an Electrolyte Solution 662.3.4.6 Ion Mobility and Ion Radius in Aqueous Solutions 672.3.4.7 Migration of Ions and the Electrical Current 682.3.4.8 The Transport Number and the Permselectivity of Ion-exchange Membranes 692.3.4.9 Interdependence of Fluxes and Driving Forces 702.3.4.10 Gas Flux through Porous Membranes, the Knudsen and Surface Diffusion and Molecular Sieving 712.3.4.11 Surface Diffusion and Capillary Condensation of Gases 732.4 Mathematical Description of Mass Transport in Membranes 742.4.1 Mass Transport Described by the Thermodynamics of Irreversible Processes 752.4.2 Mass Transport Described by the Stefan–Maxwell Equations 772.4.3 Membrane Mass Transport Models 792.4.3.1 The Solution–Diffusion Model 792.4.3.2 The Pore Flow Model and the Membrane Cut-off 84References 873 Membrane Preparation and Characterization 893.1 Introduction 893.2 Membrane Materials 893.2.1 Polymeric Membrane Materials 903.2.1.1 The Physical State of a Polymer 903.2.1.2 Crystallinity and Glass Transition Temperature 923.2.1.3 The Glass Transition Temperature and the Free Volume 933.2.1.4 Molecular Weight of a Polymer Chain 943.2.1.5 Macroscopic Structures of Polymers 953.2.1.6 Polymer Chain Interaction and Its Effect on Physical Properties 973.2.1.7 The Chemical Structure of the Polymer and Its Effect on Polymer Properties 983.2.2 Inorganic Membrane Materials 1003.2.2.1 Metal Membranes 1003.2.2.2 Glass Membranes 1013.2.2.3 Carbon Membranes 1013.2.2.4 Metal Oxide Membranes 1023.2.3 Liquid Membrane Materials 1033.3 Preparation of Membranes 1043.3.1 Preparation of Symmetric Porous Membranes 1043.3.1.1 Isotropic Membranes Made by Sintering of Powders, Stretching of Films, and Template Leaching 1063.3.1.2 Membranes Made by Pressing and Sintering of Polymer Powders 1063.3.1.3 Membranes Made by Stretching a Polymer Film of Partial Crystallinity 1073.3.1.4 Membranes Made by Track-Etching 1083.3.1.5 Membranes Made by Micro-Lithography and Etching Techniques 1093.3.1.6 Glass Membranes Made by Template Leaching 1123.3.1.7 Porous Graphite Membranes Made by Pyrolyzing Polymer Structures 1123.3.1.8 Symmetric Porous Polymer Membranes Made by Phase Inversion Techniques 1123.3.2 Preparation of Asymmetric Membranes 1143.3.2.1 Preparation of Integral Asymmetric Membranes 1153.3.3 Practical Membrane Preparation by Phase Inversion 1173.3.3.1 Temperature-Induced Membrane Preparation 1173.3.3.2 Diffusion-Induced Membrane Preparation 1183.3.4 Phenomenological Description of the Phase Separation Process 1243.3.4.1 Temperature-Induced Phase Separation Process 1253.3.4.2 Thermodynamics of a Temperature-Induced Phase Separation of a Two-Component Mixture 1263.3.4.3 The Diffusion-Induced Phase Separation Process 1333.3.4.4 Structures of Asymmetric Membranes Obtained by Phase Inversion 1363.3.4.5 Identification of Various Process Parameters in the Preparation of Phase Inversion Membranes 1363.3.4.6 General Observation Concerning the Structure of Phase Inversion Membranes 1373.3.4.7 The Selection of a Polymer/Solvent/Precipitant System for the Preparation of Membranes 1443.3.4.8 Membrane Pre- and Post-Precipitation Treatment 1483.3.5 Preparation of Composite Membranes 1493.3.5.1 Techniques Used for the Preparation of Polymeric Composite Membranes 1513.3.6 Preparation of Inorganic Membranes 1553.3.6.1 Suspension Coating and the Sol–Gel Process 1573.3.6.2 Perovskite Membranes 1583.3.6.3 Zeolite Membranes 1593.3.6.4 Porous Carbon Membranes 1603.3.6.5 Porous Glass Membranes 1613.3.7 Preparation of Homogeneous Solid Membranes 1613.3.7.1 Preparation of Liquid Membranes 1623.3.7.2 Preparation of Ion-Exchange Membranes 1643.4 Membrane Characterization 1703.4.1 Characterization of Porous Membranes 1713.4.1.1 Techniques using Microscopy 1723.4.1.2 Determination of Micro- and Ultrafiltration Membrane Fluxes 1733.4.1.3 Membrane Retention and Molecular Weight Cut-Off 1753.4.1.4 The Bacterial Challenge Test 1783.4.2 Membrane Pore Size Determination 1783.4.2.1 Air/Liquid and Liquid/Liquid Displacement 1793.4.2.2 The Bubble Point Method and Gas Liquid Porosimetry 1803.4.2.3 Liquid/Liquid Displacement 1823.4.2.4 Permporometry 1853.4.2.5 Thermoporometry 1883.4.3 Characterization of Dense Membranes 1893.4.3.1 Determination of Diffusivity in Dense Membranes 1903.4.3.2 Long-Term Stability of Membranes 1933.4.4 Determination of Electrochemical Properties of Membranes 1933.4.4.1 Hydraulic Permeability of Ion-Exchange Membranes 1943.4.4.2 The Fixed Charge Density of Ion-Exchange Membranes 1943.4.4.3 Determination of the Electrical Resistance of Ion-Exchange Membranes 1953.4.4.4 Membrane Resistance Measurements by Impedance Spectroscopy 1983.4.4.5 Permselectivity of Ion-Exchange Membranes 2033.4.4.6 Membrane Permeation Selectivity for Different Counter-ions 2063.4.4.7 Water Transport in Ion-Exchange Membranes 2073.4.4.8 Characterization of Special Property Ion-Exchange Membranes 2093.4.4.9 The Mechanical Properties of Membranes 209References 2104 Principles of Membrane Separation Processes 2134.1 Introduction 2134.2 The Principle of Membrane Filtration Processes 2144.2.1 The Principle of Microfiltration 2164.2.2 The Principle of Ultrafiltration 2194.2.3 The Principle of Nanofiltration 2234.2.4 The Principle of Reverse Osmosis 2294.2.4.1 The Reverse Osmosis Mass Transport Described by the Solution–Diffusion Model 2304.2.4.2 Reverse Osmosis Transport Described by the Phenomenological Equations 2344.2.4.3 The Water and Salt Distribution in a Polymer Matrix and the Cluster Function 2394.3 The Principle of Gas and Vapor Separation 2394.3.1 Gas Separation by Knudsen Diffusion 2404.3.2 Gas Separation by Surface Diffusion and Molecular Sieving 2414.3.3 Gas Transport in a Dense Polymer Matrix 2434.3.4 The Principle of Pervaporation 2544.3.4.1 Material Selection for the Preparation of Pervaporation Membranes 2594.4 The Principle of Dialysis 2614.4.1 Mass Transport of Components Carrying No Electrical Charges in Dialysis 2624.4.2 Dialysis Mass Transport of Electrolytes in a Membrane without Fixed Ions 2644.4.3 Dialysis of Electrolytes with Ion-Exchange Membranes 2664.5 The Principle of Electromembrane Processes 2684.5.1 Electrodialysis and Related Processes 2694.5.1.1 Mass Transport in Electrodialysis 2704.5.1.2 Electrical Current and Ion Fluxes in Electrodialysis 2724.5.1.3 The Transport Number and Membrane Permselectivity 2744.5.1.4 Membrane Counter-Ion Permselectivity 2754.5.1.5 Water Transport in Electrodialysis 2764.5.1.6 Current Efficiency in Electrodialysis 2764.5.1.7 Electrodialysis with Bipolar Membranes 2784.5.1.8 Continuous Electrodeionization 2804.5.1.9 Capacitive Deionization 2814.5.1.10 Energy Generation by Reverse Electrodialysis 2824.5.2 Electrochemical Synthesis with Ion-Exchange Membranes 2834.5.3 Ion-Exchange Membranes in Energy Storage and Conversion 2874.6 The Principle of Membrane Contactors 2924.6.1 Membrane Contactors Separating a Hydrophobic from a Hydrophilic Phase 2944.6.2 Membrane Contactors Used to Separate Two Immiscible Liquid Phases 2954.6.3 Membrane Contactors Separating a Liquid from a Gas Phase 2984.6.4 Membrane Distillation 3004.6.5 Osmotic Distillation 3054.6.6 Supported Liquid Membranes and Facilitated Transport 3064.6.7 Counter-Current Coupled Facilitated Transport 3084.7 Membrane Reactors 3114.7.1 Membrane Emulsifier 3144.8 Membrane-Based Controlled Release of Active Agents 314References 3205 Membrane Modules and Concentration Polarization 3235.1 Introduction 3235.2 Membrane Modules 3245.2.1 Membrane Holding Devices in Laboratory and Small-Scale Applications 3245.2.1.1 The Stirred Batch Cell 3255.2.1.2 The Sealed Membrane Point-of-Use Filter 3265.2.1.3 The Plate-and-Frame Membrane Module 3265.2.2 Industrial-Type Membrane Modules for Large Capacity Applications 3285.2.2.1 The Pleated Filter Membrane Cartridge 3285.2.2.2 The Spiral-Wound Module 3295.2.2.3 The Tubular Membrane Module 3315.2.2.4 The Capillary Membrane Module 3335.2.2.5 The Hollow Fiber Membrane Module 3355.2.3 Other Membrane Modules 3365.2.3.1 Membrane Modules Used in Electrodialysis and in Dialysis 3365.3 Concentration Polarization and Membrane Fouling 3405.3.1 Concentration Polarization in Filtration Processes 3425.3.1.1 Concentration Polarization without Solute Precipitation 3435.3.1.2 Concentration Polarization in Turbulent Flow Described by the Film Model 3435.3.1.3 Concentration Polarization in Laminar Flow Membrane Devices 3485.3.1.4 Rigorous Analysis of Concentration Polarization 3525.3.1.5 Membrane Flux Decline due to Concentration Polarization without Solute Precipitation 3535.3.1.6 Concentration Polarization with Solute Precipitation at the Membrane Surface 3545.3.2 Concentration Polarization in Other Membrane Separation Processes 3625.3.2.1 Concentration Polarization in Dialysis and Electrodialysis 3635.3.2.2 Concentration Polarization in Electrodialysis 3665.3.2.3 Concentration Polarization in Gas Separation 3715.3.2.4 Concentration Polarization in Pervaporation 3735.3.3 Membrane Fouling and Its Causes and Consequences 3735.3.3.1 Prevention of Membrane Fouling 375References 3786 Membrane Process Design and Operation 3816.1 Introduction 3816.2 Membrane Filtration Processes 3816.2.1 Recovery Rate, Membrane Rejection, Retentate, and Filtrate Concentrations 3826.2.1.1 Solute Losses in Membrane Filtration Processes 3866.2.1.2 Operation Modes in Filtration Processes 3876.2.1.3 Reverse Osmosis Process Design 3886.2.1.4 Stages and Cascades in Membrane Filtration 3926.2.1.5 Ultra- and Microfiltration Process Design 3956.2.1.6 Ultrafiltration Process Design 4016.2.1.7 Diafiltration 4036.2.2 Costs of Membrane Filtration Processes 4066.2.2.1 Energy Requirements in Filtration Processes 4066.2.2.2 Investment- and Maintenance-Related Costs in Filtration Processes 4116.3 Gas Separation 4126.3.1 Gas Separation Process Design and Operation 4136.3.1.1 Staging in Gas Separation and the Reflux Cascade 4196.3.2 Energy Consumption and Cost of Gas Separation 4216.4 Pervaporation 4226.4.1 Pervaporation Modes of Operation 4246.4.1.1 Staging and Cascades in Pervaporation 4256.4.2 Pervaporation Energy Consumption and Process Costs 4286.5 Dialysis 4286.5.1 Dialysis Process and System Design 4306.5.1.1 Dialyzer Membrane Module Constructions 4316.5.2 Process Costs in Dialysis 4356.6 Electrodialysis and Related Processes 4366.6.1 Process Design in Conventional Electrodialysis 4366.6.1.1 Operation of the Electrodialysis Stacks in a Desalination Plant 4416.6.2 Process Costs in Electrodialysis 442References 444Appendix A 447Questions and Exercises 447Appendix B 457Index 465

“The synopsis for the book states that it is aimed at 'advanced students as well as process and chemical engineers working in industry'. I would fully support this view and wholeheartedly recommend the book to such practitioners and similarly interested readers. It is a worthy addition to anyone's bookshelf.”  (Chemistry World, 2012)