MEMBRANE SEPARATION SYSTEMS Recent Developments and Future Directions R.W. Baker, E.L. Cussler, W. Eykamp, W.J. Koros, R.L. Riley, H. Strathmann NOYES DATA CORPORATION Park Ridge, New Jersey, U.S.A. Copyright @ 1991 by Noyes Data Corporation Library of Congress Catalog Card Number: 90.23675 ISBN: O-8155-1270-8 Printed in the United States Published in the United States of America by Noyes Data Corporation Mill Road, Park Ridge, New Jersey 07656 10987654321 Library of Congress Cataloging-in-Publication Data Membrane separation systems : recent developments and future directions I by R.W. Baker . . . [et al.1 . p. cm. Includes bibliographical references and index. ISBN O-8155-1270-8 : 1. Membrane separation. I. Baker, R.W. (Richard W.) TP248.25.M46M456 1991 660’2842 dc20 9923675 CIP Acknowledgments This report was prepared by the following group of experts: Dr. Richard W. Baker (Membrane Technology & Research, Inc.) Dr. Edward Cussler (University of Minnesota) Dr. William Eykamp (University of California at Berkeley) Dr. William J. Koros (University of Texas at Austin) Mr. Robert L. Riley (Separation Systems Technology, Inc.) Dr. Heiner Strathmann (Fraunhofer Institute, West Germany). Mrs. Janet Farrant and Dr. Amulya Athayde edited the report, and also served as project coordinators. The following members of the Department of Energy (DOE) made valuable contributions to the group meetings and expert workshops: Dr. Richard Gordon (Office of Energy Research, Division of Chemical Sciences) Dr. Gilbert Jackson (Office of Program Analysis) Mr. Robert Rader (Office of Program Analysis) Dr. William Sonnett (Office of Industrial Programs) The following individuals, among others, contributed to the discussions and recommendations at the expert workshops: Dr. B. Bikson (Innovative Membrane Systems/Union Carbide Corp.) Dr. L. Costa (Ionics, Inc.) Dr. T. Davis (Graver Water, Inc.) Dr. D. Elyanow (Ionics, Inc.) Dr. H. L. Fleming (GFT, Inc.) Dr. R. Goldsmith (CeraMem Corp.) Dr. G. Jonsson (Technical University of Denmark) Dr. K V. Peinemann (GKSS, West Germany) Dr. R. Peterson (Filmtec Corp.) Dr. G. P. Pez (Air Products & Chemicals, Inc.) Dr. H. F. Ridgway (Orange County Water District) Mr. J. Short (Koch Membrane Systems, Inc.) Dr. K. Sims (Ionics, Inc.) Dr. K. K. Sirkar (Stevens Institute of Technology) Dr. J. D. Way (SRI International) The following individuals served as peer reviewers of the final report: Dr. J. L. Anderson (Carnegie Mellon University) Dr. J. Henis (Monsanto) Dr. J. L. Humphrey (J. L. Humphrey and Associates) Dr. S T. Hwang (University of Cincinnati) Dr. N.N. Li (Allied Signal) Dr. S. L. Matson (Sepracor, Inc.) Dr. R. D. Noble (University of Colorado) Dr. M. C. Porter (M. C. Porter and Associates) Dr. D. L. Roberts (SRI International) Dr. S. A. Stern (Syracuse University) 2 Acknowledgments 3 Additional information on the current Federal Government support of membrane research was provided by: Dr. D. Barney Dr. R. Bedick Dr. R. Delafield Dr. C. Drummond Dr. R. Gajemki Dr. L. Jarr Dr. R. Cortesi Dr. G. Ondich PJational Once Foundation Dr. D. Bruley Dr. D. Greenberg Foreword This book discusses recent developments and future directions in the field of membrane separation systems. It describes research needed to bring energy-sav- ing membrane separation processes to technical and commercial readiness for commercial acceptance within the next 5 to 20 years. The assessment was con- ducted by a group of six internationally known membrane separations experts who examined the worldwide status of research in the seven major membrane areas. This encompassed four mature technology areas: reverse osmosis, micro- filtration, ultrafiltration, and electrodialysis; two developing areas: gas separa- tion and pervaporation; and one emerging technology: facilitated transport. Membrane based separation technology, a relative newcomer on the separation scene, has demonstrated the potential of saving enormous amounts of energy in the processing industries if substituted for conventional separation systems. It has been estimated that over 1 quad annually, out of 2.6, can possibly be saved in liquid-to-gas separations, alone, if membrane separation systems gain wider acceptance. In recent years great strides have been made in the field and even greater future energy savings should be available when these systems are substituted for such conventional separation techniques as distillation, evapora- tion, filtration, sedimentation, and absorption. The book pays particular attention to identifying currently emerging innova- tive processes, and to further improvements which could gain even wider accep- tance for the more mature membrane technologies. In all, 38 priority research areas were selected and ranked in order of priority, according to their relevance, likelihood of success, and overall impact. Rationale was presented for all the final selections; and the study was peer reviewed by an additional ten experts. The topics that were pointed out as having the greatest research emphasis are pervaporation for organic-organic separations; gas separations; microfiltration; an oxidant-resistant reverse osmosis membrane; and a fouling-resistant ultra- filtration membrane. V vi Foreword The information in the book is from Membrane Separation Systems, Volume I- Executive Summary, and Volume II-Final Report, by the Department of Energy Membrane Separation Systems Research Needs Assessment Group, authored by R.W. Baker, E.L. Cussler, W. Eykamp, W.J. Koros, R.L. Riley, and H. Strathmann. The report was prepared by Membrane Technology & Research, Inc. of Menlo Park, California, for the U.S. Department of Energy Office of Program Analysis, April 1990. The table of contents is organized in such a way as to serve as a subject index and provides easy access to the information contained in the book. Advanced composition and production methods developed by Noyes Data Corporation are employed to bring this durably bound book to you in a minimum of time. Special techniques are used to close the gap between “manuscript” and “completed book.” In order to keep the price of the book to a reasonable level, it has been partially reproduced by photo-offset directly from the original report and the cost saving passed on to the reader. Due to this method of publishing, certain portions of the book may be less legible than desired. NOTICE The studies in this book were sponsored by the U.S. Department of Energy. On this basis the Publisher assumes no responsibility nor liability for errors or any consequences arising from the use of the information contained herein. Mention of trade names, commercial products, and suppliers does not constitute endorsement or recommen- dation for use by the Agency or the Publisher. Final determination of the suitability of any information or product for use contemplated by any user, and the man- ner of that use, is the sole responsibility of the user. The book is intended for informational purposes only. The reader is warned that caution must always be ex- ercised when dealing with hazardous materials in mem- brane separation systems, and expert advice should be obtained before implementation is considered. Contents and Subject Index VOLUME I 1. EXECUTIVE SUMMARY. .4 References. .8 2. ASSESSMENT METHODOLOGY .9 2.1 Authors. .9 2.2 Outline and Model Chapter. .I2 2.3 First Group Meeting. .I2 2.4 Expert Workshops. .I2 2.5 Second Group Meeting. .17 2.6 Japan/Rest of the World Survey. 17 2.7 Prioritization of Research Needs. 17 2.8 Peer Review. .I7 References. .I8 3. INTRODUCTION. .19 3.1 Membrane Processes. .I9 3.2 Historical Development .27 3.3 The Future. .29 3.3.1 Selectivity .29 3.3.2 Productivity. .30 3.3.3 Operational Reliability. .31 References. .33 4. GOVERNMENT SUPPORT OF MEMBRANE RESEARCH .34 4.1 Overview .34 4.2 U.S. Government Supported Membrane Research .37 4.2.1 Department of Energy .37 vii viii Contents and Subject Index 4.2.1.1 Office of Industrial Programs/Industrial Energy Conservation Program 4.2.1.2 Office of Energy Research/Division of Chemical Sciences. 4.2.1.3 Office of Energy Research/Division of Advanced Energy Projects. 4.2.1.4 Office of Fossil Energy. 4.2.1.5 Small Business Innovative Research Program. 4.2.2 National Science Foundation. 4.2.3 Environmental Protection Agency 4.2.4 Department of Defense. 4.2.5 National Aeronautics and Space Administration 4.3 Japanese Government Supported Membrane Research 4.3.1 Ministry of Education 4.3.2 Ministry of International Trade and Industry (MITI) 4.3.2.1 Basic Industries Bureau. 4.3.2.2 Agency of Industrial Science and Technology (AIST) 4.3.2.3 Water Re-Use Promotion Center (WRPC) 4.3.2.4 New Energy Development Organization (NEDO). 4.3.3 Ministry of Agriculture, Forestry and Fisheries 4.4 European Government Supported Membrane Research. 4.4.1 European National Programs. 4.4.2 EEC-Funded Membrane Research. 4.5 The Rest of the World .37 .39 .40 .41 .42 .45 .46 .47 .48 .48 .49 .49 .49 .50 .51 .52 .52 .52 .53 .54 .55 5. ANALYSIS OF RESEARCH NEEDS .56 5.1 Priority Research Topics. .56 5.2 Research Topics by Technology Area .65 5.2.1 Pervaporation .66 5.2.2 Gas Separation .68 5.2.3 Facilitated Transport. .70 5.2.4 Reverse Osmosis .72 5.2.5 Microfiltration .74 5.2.6 Ultrafiltration. .76 5.2.7 Electrodialysis .78 5.3 Comparison of Different Technology Areas .79 5.4 General Conclusions. .81 References. .84 APPENDIX A. PEER REVIEWERS’ COMMENTS .86 A.1 General Comments .86 A.l.l The Report Is Biased Toward Engineering, or Toward Basic Science .86 A.1.2 The Importance of Integrating Membrane Technology Into Total Treatment Systems. .87 A.1.3 The Ranking Scheme .88 Contents and Subject Index ix A.1.4 Comparison with Japan .89 A.2 Specific Comments on Applications .90 A.2.1 Pervaporation .90 A.2.2 Gas Separation .91 A.2.3 Facilitated Transport. .91 A.2.4 Reverse Osmosis .92 A.2.5 Ultrafiltration. .92 A.2.6 Microfiltration .93 A.2.7 Electrodialysis .93 A.2.8 Miscellaneous Comments .93 VOLUME II INTRODUCTION TO VOLUME II. .96 References. .99 1. MEMBRANE AND MODULE PREPARATION. 100 R.W. Baker 1 .I Symmetrical Membranes. 102 1.1.1 Dense Symmetrical Membranes 102 1.1.1.1 Solution Casting. 102 1.1.1.2 Melt Pressing 102 1.1.2 Microporous Symmetrical Membranes. 105 1.1.2.1 Irradiation 105 1.1.2.2 Stretching 105 1.1.2.3 Template Leaching 109 1.2 Asymmetric Membranes 109 1.2.1 Phase Inversion (Solution-Precipitation) Membranes. 109 1.2.1 .I Polymer Precipitation by Thermal Gelation 110 1.2.1.2 Polymer Precipitation by Solvent Evaporation . 114 1.2.1.3 Polymer Precipitation by lmbibition of Water Vapor .I14 1.2.1.4 Polymer Precipitation by Immersion in a Nonsolvent Bath (Loeb-Sourirajan Process) 116 1.2.2 Interfacial Composite Membranes. 118 1.2.3 Solution Cast Composite Membranes. 121 1.2.4 Plasma Polymerization Membranes 123 1.2.5 Dynamically Formed Membranes 125 1.2.6 Reactive Surface Treatment. 125 1.3 Ceramic and Metal Membranes. 126 1.3.1 Dense Metal Membranes 126 1 .3.2 Microporous Metal Membranes. 126 1.3.3 Ceramic Membranes. 126 1.3.4 Molecular Sieve Membranes. 127 1.4 Liquid Membranes. 131 1.5 Hollow-Fiber Membranes 132 1.5.1 Solution (Wet) Spinning. 134 1.5.2 Melt Spinning 134 x Contents and Subject Index 1.6 Membrane Modules 136 1.6.1 Spiral-Wound Modules 136 1.6.2 Hollow-Fiber Modules 140 1.6.3 Plate-and-Frame Modules 140 1.6.4 Tubular Systems. .I40 1.6.5 Module Selection. 140 1.7 Current Areas of Membrane and Module Research. 144 References. .I46 2. PERVAPORATION. .151 R. W. Baker 2.1 Process Overview. 151 2.1 .I Design Features. 154 2.1.2 Pervaporation Membranes. 156 2.1.3 Pervaporation Modules. 156 2.1.4 Historical Trends. 159 2.2 Current Applications, Energy Basics and Economics. 160 2.2.1 Dehydration of Solvents. 161 2.2.2 Water Purification. 164 2.2.3 Pollution Control 169 2.2.4 Solvent Recovery 171 2.2.5 Organic-Organic Separations 174 2.3 Industrial Suppliers 176 2.4 Sources of Innovation 180 2.5 Future Directions 182 2.5.1 Solvent Dehydration 182 2.5.2 Water Purification 184 2.5.3 Organic-Organic Separations 184 2.6 DOE Research Opportunities. 185 2.6.1 Priority Ranking 186 2.6.1 .I Solvent Dehydration 186 2.6.1.2 Water Purification. 186 2.6.1.3 Organic-Organic Separations 186 References. 187 3. GAS SEPARATION. .I89 NJ. Koros 3.1 Introduction. 189 3.2 Fundamentals. .I91 3.3 Membrane System Properties. 193 3.4 Module and System Design Features 195 3.5 Historical Perspective. 199 3.6 Current Technical Trends in the Gas Separation Field. 200 3.6.1 Polymeric Membrane Materials. 200 3.6.2 Plasticization Effects 203 3.6.3 Nonstandard Membrane Materials. 205 3.6.4 Advanced Membrane Structures. 205 3.6.5 Surface Treatment to Increase Selectivity. 205 [...]... Programs on liquid-to- over 1.0 quad separation systems of more widely Membrane separation processes processes, existing separation membrane of Program order of their research 2.1 systems significant to consuming are compact Analysis, impact to identify on the advantages less energy and modular, This study was commissioned may produce mission, the most effective than enabling membrane such that existing conventional... diameters to membranes Microfiltration large colloids membranes from by the membrane are used solutions osmosis to filter Ultrafiltration 19 differ Microfiltration from principally in the is considered to 0.1 pm (1,000 A) to IO pm suspended refers to be systems particulates to membranes bacteria having or pore 20 Membrane diameters filter Separation in the range dissolved applications whey, Systems macromolecules,... selectively separation separation pervaporation industrial a significant of a membrane permeable At gas separation currently The membrane separation techniques to capture gas separation, Gas pervaporation developed gas processes: 23 methane current in research will expand rapidly over the next few years Pervaporation reverse osmosis is a relatively new process In pervaporation, and gas separation in... Modules Composite Membrane 4.2 207 Improved 3.13.7 Membrane Oxygen-Selective 3.13.4 4.1 206 System Applications 3.13.1 xi Index Design and Operating Trends Hydrogen Separations 3.7.1 Oxygen-Nitrogen Separations 3.7.2 Acid Gas Separations 3.7.3 Vapor-Gas Separations 3.7.4 Nitrogen-Hydrocarbon Separations 3.7.5 Helium Separations 3.7.6 Energy Basics Economics ... (University as Principal science based on the type of membrane was The executive and also served of membrane of senior & Research, Inc.), who were responsible Dr Eykamp The by a group and technology W Baker (Membrane of offer In addition applications Office systems (Fraunhofer primary Institute, responsibility was were of West for a topic 10 Membrane Separation Systems Table 2- 1 List of Authors Innir, Author... Composite Membrane Research 5.6.4.1 Increasing Water Production Efficiency 5.6.4.2 Seawater Reverse Osmosis Membranes 5.6.4.3 Low-Pressure Membranes 5.6.4.4 Ultra-Low-Pressure Membranes Reverse Osmosis 295 299 299 Low-Pressure 291 Membrane Applications 289 289 of the Reverse Osmosis Osmosis 5.5.5 Products Reverse Systems .289 Inventory Sales 5.3 5.5.4 Plant of Membrane. .. quads.’ membrane topics research 28% of the energy refineries.s research electrodialysis, items experts Based on group meetings priority of organic-solvent-resistant ranking separation catalytic to have additional which were then ranked in order of priority separations separation membrane of six membrane technology microfiltration, transport 38 research which the are believed by a group of membrane. .. on consisted Methodology on Society was held membrane was also held at were present attendees and The lists 14 Membrane Separation Systems Table 2-2 WORKSHOP Workshop ON ULTRAFILTRATION Attendees AND MICROFILTRATION Attendee Affiliation W Eykamp (Author) G Jackson R Rader J Short G Jonsson A L Athayde University of California, Berkeley DOE DOE Koch Membrane Systems, Inc Technical University of Denmark... the United leader threat to the subject systems, for The attendant over a much broader because and emphasis would increase would become competitive technologies The dominant of erosion high-performance, States membranes gas separation by Japanese Increased and development generation of gas -separation Membrane- based is under institutions controlled based gas separation list was a world suppliers, governments... differing principally in the average pore diameter of the membrane filter Reverse osmosis membranes are so dense that discrete pores do not exist Transport in this case occurs via statistically distributed free volume areas The relative size of different solutes removed by each class of membrane is illustrated in this schematic 22 Membrane Separation Systems Pick-up ~olullon Cathode fed To salt solution . conventional separation systems. It has been estimated that over 1 quad annually, out of 2.6, can possibly be saved in liquid-to-gas separations, alone, if membrane separation systems gain. information in the book is from Membrane Separation Systems, Volume I- Executive Summary, and Volume II-Final Report, by the Department of Energy Membrane Separation Systems Research Needs Assessment. Metal Membranes. 126 1.3.1 Dense Metal Membranes 126 1 .3.2 Microporous Metal Membranes. 126 1.3.3 Ceramic Membranes. 126 1.3.4 Molecular Sieve Membranes. 127 1.4 Liquid Membranes.