Development of mixed matrix membranes for gas separation application

DEVELOPMENT OF MIXED MATRIX MEMBRANES FOR GAS SEPARATION APPLICATION LI YI (M. Eng., Tsinghua University, P. R. China) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF CHEMICAL AND BIOMOLECULAR ENGINEERING NATIONAL UNIVERSITY OF SINGAPORE 2006 ACKNOWLEDGEMENTS I wish to take this opportunity to express my sincere appreciation to all the contributors whose cooperation and assistance were essential in helping me to gradually acquire sharper tools toward the completion of my PhD study reported herein: First of all, I especially wish to record my deepest appreciation and thanks to Prof. Chung. He has given me every opportunity to learn about membrane science and provide the essential facilities to carry out my research. His enthusiasm, positive outlook and belief in my abilities kept me going through the most difficult phase of research. I am also indebted to my co-supervisors, Dr. Pramoda Kumari Pallathadka and Dr. Liu Ye for their keen efforts and consistent consultation throughout my candidature. I may also like to express my appreciation to my PhD thesis committee members, Prof. Hong Liang and Dr. Chen Jia Ping. Their suggestions on my PhD proposal were constructive throughout my candidature in NUS. Special thanks are due to all the team members in Prof. Chung’s research group. Dr. Cao Chun and Ms. Jiang Lan Ying are especially recognized for their guidance and help in my initial study step. Special thanks go to Dr. Huang Zhen for providing the i zeolite Beta and Ms. Guan Huai Min for providing the silane modification method of zeolite surface that are indispensable to my research. The suggestions on permeation cell set-up and modification from Ms. Chng Mei Lin and Dr. Tin Pei Shi were precious. All the members in Prof. Chung’s group are kind and helpful to me, which have made my study in NUS enjoyable and memorable. I would like to gratefully acknowledge the research scholarship offered to me by the National University of Singapore (NUS), which provided me a positive, conducive and professional atmosphere for researching. Appreciation also goes to the staff in the Department of Chemical and Biomolecular Engineering that have helped me in various characterization techniques and given me professional suggestions. I would also like to convey my thanks to Dr. S. Kulprathipanja from UOP LLC for his valuable advices in my work on mixed matrix membranes and zeolites. Thanks also go to NUS and UOP LLC for the financial support with the grant numbers of R-279-000108-112, R-279-000-140-592, R-279-000-140-112 and R-279-000-184-112. Last but not least, I must express my special thanks to my wife, Wu Qiong, for her unwavering and unconditional love and support. My family members also deserve the special recognition for their love and endless encouragement and support. ii TABLE OF CONTENTS Page ACKNOWLEDGEMENT…………………………………………….……………… i TABLE OF CONTENTS…………………………………………………………… iii SUMMARY………………………………………………………………… ………xii NOMENCLATURE………………………………………………………….………xv LIST OF TABLES………………………………………………………………… xxii LIST OF FIGURES…………………………………………………………………xxv CHAPTER INTRODUCTION OF GAS SEPARATION MEMBRANE……….1 1.1 Scientific Milestones…………… .…………………………………………….3 1.2 Importance of Gas Separations Using Membranes………………….………….7 1.2.1 Separation of O2 and N2…………….…………………………………. 1.2.2 Separation of H2 and Hydrocarbon Gases……….…………………….10 1.2.3 Separation of H2 and CO……………………….…………………… .10 1.2.4 Separation of H2 and N2……………………………………….………11 1.2.5 Acid Gas Removal from Natural Gas…………………………… …12 1.3 Basic Concept of Membrane Separation………………………………………14 1.4 Types of Membrane Structures……………………………………………… 18 1.4.1 Dense vs. Porous Membranes…………………………………… … 18 1.4.2 Symmetric vs. Asymmetric Membranes…………….……………… .19 1.4.3 Dynamic in-situ Membranes………………………………….……….22 iii 1.4.4 Liquid Membranes…………………………………………….…… 23 1.5 Mechanisms of Membrane Separation……………………………………… .24 1.5.1 Poiseuille Flow……………………………………………………… .25 1.5.2 Knudsen Diffusion…………………………………………………….25 1.5.3 Molecular Sieving…………………………………………………… 26 1.5.4 Solution-diffusion…………………………………………………… 28 1.5.4.1 Diffusion……… ………… …………………………………29 1.5.4.2 Sorption……………………………………………………… 30 1.5.4.3 Selectivity…………………………………………………… .31 1.6 Membrane Modules and Design Instructions……………….……………… 33 1.6.1 Plate-and-Frame Modules……….…………………………………….33 1.6.2 Spiral-Wound Modules…………………….………………………….34 1.6.3 Hollow-Fiber Modules…………………….…………….…………….35 1.7 Research Objectives and Organization of Dissertation……………………… 37 1.8 References…………………………………………………………………… 41 CHAPTER MIXED MATRIX MEMBRANES FOR GAS SEPARATION… 48 2.1 Emergence of Mixed Matrix Membranes…………………………………… 48 2.1.1 Polymeric (Organic) Membrane Materials……………………………50 2.1.2 Inorganic Membrane Materials……………………………………… 53 2.1.3 Mixed Matrix Membranes (MMMs)………………………………… 57 2.2 Development of Mixed Matrix Membrane………………………………… 58 iv 2.2.1 Flat Dense Mixed Matrix Membranes……………… ….……………58 2.2.2 2.3 Hollow Fiber Mixed Matrix Membranes……………………….…… 64 Prediction of Gas Separation Performance of MMMs………………….…… 66 2.3.1 Prediction for MMMs with an Ideal Interface……………………… .66 2.3.2 Prediction for MMMs with an Nonideal Interface………….…………67 2.4 References……………………………………………………….…………….73 CHAPTER MATERIALS AND EXPERIMENTAL PROCEDURES….… …81 3.1 Materials……………………………………………………………………….82 3.1.1 Polymers………………………………………………………….……82 3.1.2 Molecular Sieves………………………………………………………83 3.1.3 Silane Coupling Agents………………………………… .………… 84 3.1.4 Others…………………………………………………………… … .85 3.2 Fabrication of Dual-layer PES Hollow Fiber Membranes with a Neat Polymeric Outer Layer…………………………………………………………….…… 85 3.2.1 Spinning Line………………………………………………………….85 3.2.2 Preparation of Spinning Dope…………………………………………86 3.2.3 Spinning Process and Solvent Exchange…………………………… .87 3.2.4 Post-treatment Protocols………………………………………………88 3.3 Fabrication of Flat Dense PES-Zeolite A Mixed Matrix Membranes with Silane Modified Zeolite or Unmodified zeolite………………………………… ….90 3.3.1 Chemical Modification Method of Zeolite Surface… ……….………90 v 3.3.2 Preparation Procedures of Flat Dense Mixed Matrix Membranes…….91 3.4 Fabrication of Dual-layer PES/P84 Hollow Fiber Membranes with a PESZeolite Beta Mixed Matrix Outer Layer………………………………… ….92 3.4.1 Preparation of Spinning Dope…………………………………………92 3.4.2 Spinning Process and Solvent Exchange…………………………… .93 3.4.3 Post-treatment Methods……………………………………………….94 3.5 Characterization of Physical Properties…………………………………….…95 3.5.1 Brunauer-Emmett-Teller (BET)…………………………………….…95 3.5.2 Dynamic Light Scattering (DLS)……………….………………… …95 3.5.3 Differential Scanning Calorimetry (DSC)…………………………….95 3.5.4 Elemental Analysis………………………………………………… 96 3.5.5 Scanning Electron Microscope (SEM)………………………… ……97 3.5.6 Energy Dispersion of X-ray (EDX)………………………….…… …97 3.5.7 X-ray Photoelectron Spectroscopy (XPS)…………………………… 98 3.5.8 X-ray Diffraction (XRD)…………………………………… ….……98 3.6 Characterization of Gas Transport Properties…………… ………….……….98 3.6.1 Pure Gas Permeation Test…………………………………………… 99 3.6.1.1 Neat Polymeric hollow fibers…………… …………….…….99 3.6.1.2 Flat Dense Neat Polymeric or Mixed Matrix Membranes… .101 3.6.1.3 Mixed Matrix Hollow Fibers…………… ………….………105 3.6.2 Mixed Gas Permeation Test………………………………….………107 3.6.2.1 Neat Polymeric hollow fibers………………………….…….107 vi 3.6.2.2 Flat Dense Neat Polymeric or Mixed Matrix Membranes ….108 3.6.2.3 Mixed Matrix Hollow Fibers………………….……… ……112 3.7 References……………………………………………………………………112 CHAPTER FABRICATION OF DUAL-LAYER POLYETHERSULFONE (PES) HOLLOW FIBER MEMBRANES WITH AN ULTRATHIN DENSE SELECTIVE LAYER FOR GAS SEPARATION… .115 4.1 Introduction…………………………………………………………… ……115 4.2 Results and Discussion……………………………………………………….119 4.2.1 The Effect of Different Post-treatment Protocols on Gas Separation Performance……………………………………… …………… 119 4.2.2 Membrane Morphology………………………………………… ….122 4.3 Conclusions…………………………………………… ……………………128 4.4 References……………………………………………………………………129 CHAPTER THE EFFECTS OF POLYMER CHAIN RIGIDIFICATION, ZEOLITE PORE SIZE AND PORE BLOCKAGE ON POLYETHERSULFONE (PES)-ZEOLITE A MIXED MATRIX MEMBRANES… 135 5.1 Introduction………………………………………………………………… 135 5.2 Results and Discussion……………………………………………………….138 vii 5.2.1 Effect of Membrane Preparation Methodology on Gas Separation Performance…………………………………………………………138 5.2.2 Effect of Zeolite Loadings on Gas Separation Performance…… ….142 5.2.3 New Modified Maxwell Model to Predict Gas Separation Performance…………………………………………………………149 5.2.4 Effect of Pore Sizes of the Zeolite on Gas Separation Performances 154 5.3 Conclusions………….………… …… …………………………….………156 5.4 References……………………………………………………………………158 CHAPTER EFFECTS OF NOVEL SILANE MODIFICATION OF ZEOLITE SURFACE ON POLYMER CHAIN RIGIDIFICATION AND PARTIAL PORE BLOCKAGE IN POLYETHERSULFONE (PES)-ZEOLITE A MIXED MATRIX MEMBRANES.… .162 6.1 Introduction…………………… ………………………………… 162 6.2 Results and Discussion……………………………………………………….165 6.2.1 Characterization and Comparison of Unmodified and Modified Zeolites…………………………….…………………………… ….165 6.2.2 Effect of Chemical Modification of Zeolite Surface on Gas Separation Performance…………………………………………………………168 6.2.3 Effect of Zeolite Loadings on Gas Permeability……………….…….173 6.2.4 Effect of Zeolite Loadings on Gas Permselectivity….……… …… 177 viii 6.2.5 Applicability of the Modified Maxwell Model to Predict Gas Separation Performance…………………………………………………………178 6.3 Conclusions………………………………………………………………… 186 6.4 References………………………………………………… .……………….188 CHAPTER DUAL-LAYER POLYETHERSULFONE (PES)/BTDA-TDI/MDI CO-POLYIMIDE (P84) HOLLOW FIBER MEMBRANES WITH A SUBMICRON PES-ZEOLITE BETA MIXED MATRIX DENSE-SELECTIVE LAYER FOR GAS SEPARATION… 192 7.1 Introduction………………………………………………… ………………192 7.2 Results and Discussion……………………………………………………….197 7.2.1 Effects of Heat-treatment Temperature on Gas Separation Performance……………………………….…………………… ….197 7.2.2 Effect of Mixed Matrix Outer-layer Thickness on Gas Separation Performance………………………… .…………………………….201 7.2.3 Effect of Air Gap on Gas Separation Performance………… ………206 7.2.4 Mixed Gas Separation Performance….………… ………………….208 7.3 Conclusions………………………………………………………….……….209 7.4 References……………………………………………………………………210 CHAPTER CONCLUSIONS AND RECOMMENDATIONS… 217 8.1 Conclusions……………………………………………… …………………217 ix Needle valve Needle valve Feed outlet Mass flow controller (2) inlet outlet O2 analyzer Needle valve Atmosphere outlet Needle valve inlet Mass flow controller (1) VCR Union Tee inlet Retentate 5-minute epoxy Vacuum pump 73.7mm A module consisting of hollow fibers Pressure gauge Permeate Bubble flow meter 8-hour epoxy Gas reservoir Needle valve Gas cylinder (air) Inner diameter: 10.2mm Figure B.1: Schematic diagram of apparatus using an oxygen analyzer for O2/N2 mixed gas permeation tests through a hollow fiber module 238 Table B.1: Module specifications and experimental conditions (24°C) Membrane name Hollow fiber Hollow fiber Membrane material Composite membranes based on polyethersulfone Composite membranes based on polysulfone Outer diameter of fibers (μm) 950 1000 Inner diameter of fibers (μm) 520 550 Length of fibers (cm) 5.5 4.5 Number of fibers 11 Compositions of mixed gas 21 mol%±1% O2 in air or CO2/CH4 (50/50 mol%) 21 mol%±1% O2 in air or CO2/CH4 (50/50 mol%) Feed gas pressure (psig) 200 (for air separation) or 190 (for CO2/CH4) 200 (for air separation) or 200 (for CO2/CH4) Permeate gas pressure (psig) ~0 ~0 Retentate flow rate (ml/min) 0.50 (for air separation) 1.38 (for CO2/CH4) 0.57 (for air separation) 2.70 (for CO2/CH4) Permeate flow rate (ml/min) 0.0219 (for air separation) 0.0819 (for CO2/CH4) 0.0283 (for air separation) 0.135 (for CO2/CH4) 239 In order to obtain accurate mixed gas permeation results, the testing system comprises the following four steps. The first step is to decide the retentate and permeate flow rates by a mass flow controller and bubble flow meter, respectively. The model of mass flow controller used in this work is GFC 17 (Aalborg®), which costs S$1,740 (about US$1,000) including calibration. Its measurement range is 0-10ml/min (under standard temperature and pressure). The accuracy of mass flow controller is around ±1.5% of full scale. For different gases, the actual flow rate is the product of the set point of the mass flow controller times an adjustable coefficient because this equipment was calibrated with N2 as received. In our case, the adjustable coefficient is approximately equal to for air because the adjustable coefficient is for N2 and 0.996 for O2. The following briefly describes our procedure to control the stage cut approximately at or below 5% to eliminate the effect of concentration polarization [11, 18]. Firstly, the set point of mass flow controller (1) (see Figure B.1) was randomly set at a certain value, for example 2ml/min. Secondly, the permeate flow rate was measured by the bubble flow meter shown in Figure B.1. If the ratio of permeate flow rate to retentate flow rate is around 0.05 or lower (i.e. the stage cut was at or below 0.05), the first step (i.e. measurement of flow rates) was finished. Otherwise, the set point of mass flow controller (1) would be readjusted to a new value until this requirement was achieved. In this part of work, the ultimate retentate and permeate flow rates in the mixed O2 and 240 N2 separation were 0.50 and 0.0219 ml/min for hollow fiber 1, respectively; and were 0.57 and 0.0283 ml/min for hollow fiber 2, respectively, as shown in Table B.1. The second step is to measure the composition of retentate gas using the oxygen analyzer. An Advanced Micro Instrument (AMI) oxygen analyzer (model 201) was applied in this study. The analyzer costs S$5500 (about US$3,300), inclusive of the installation fee. Its measurement range is 0-100% O2 concentration. This O2 analyzer is calibrated on air and its reading is adjusted to 20.9 in the calibration at moderate temperature and humidity. Both sensitivity and accuracy of AMI model 201 oxygen analyzer used in this part of work are 0.5% of full scale. Therefore, the measurement error from oxygen analyzer is much smaller compared with that from the mass flow controller, and the oxygen analyzer is sensitive and accurate enough to measure the concentration changes in feed and retentate gases. The measurement of O2 concentration is carried out by an electrochemical oxygen sensor, the basic functioning of which is similar to a battery. Oxygen gas diffuses through a membrane; contacts an electrode and is reduced to a negatively charged hydroxyl ion. This ion moves through an electrolyte in the oxygen sensor to a positively charged electrode typically made of lead. The hydroxyl ion reacts with the lead and releases electrons. The electron flow is measured and can mathematically be converted to an oxygen concentration. This electrochemical oxygen sensor is sealed in the cell compartment of O2 analyzer by an O-ring. The gas sample can only enter and 241 exit from the cell compartment through the ¼ inch Swagelok® tube; therefore, there is no internal leak within the O2 analyzer. Because the retentate flow rate was too small in our study, it was impossible to produce a high positive pressure from the inlet to the outlet of the oxygen analyzer to prevent the interference of atmosphere entering into the oxygen analyzer. To overcome this problem, a special design was made here. Another mass flow controller (denoted as mass flow controller (2)) was connected with the O2 analyzer, as shown in Figure B.1. As a result, the gas can only flow from the inlet to the outlet in the mass flow controller and cannot flow inversely due to its special inner structure; therefore, the gas in atmosphere could not diffuse into the system. This design (i.e. the use of the second mass flow controller) is very important because it significantly extends the application range of our testing system at various gas flow rates. After opening the needle valves 2, and and closing the needle valve 4, the line from the outlet of mass flow controller (1) to the outlet of mass flow controller (2) was evacuated to remove the residual gas of the system (i.e., hollow fiber module and tubing) before test. The electric power of O2 analyzer must be shut down during this period; otherwise, this action may damage the sensor of O2 analyzer by boiling the electrolyte. Thereafter, the needle valves and were closed and the electric power of O2 analyzer was turned on. Thereupon, the retentate gas accumulated inside the O2 analyzer was indicated by a gradual increase in the reading of O2 analyzer. After an 242 appropriate period of time, needle valves and were opened and the superfluous gas stored in the O2 analyzer streamed into the atmosphere through the mass flow controller (2). The set point of mass flow controller (2) should be regulated to a value slightly higher than that of the mass flow controller (1) in order to eliminate the accumulation of the retentate gas in the O2 analyzer, which may mislead the reading. With a decrease in the superfluous gas contents in the O2 analyzer, the set point of mass flow controller (2) should be gradually adjusted until it was the same as that of the mass flow controller (1) (i.e. 0.50ml/min for hollow fiber and 0.57ml/min for hollow fiber 2). Under these conditions, the O2 analyzer would provide a stable and reliable reading of O2 concentration in the retentate gas. The above proposed operation sequence is very critical to obtain a stable and accurate gas flow rate through the O2 analyzer, especially at low gas flow rates, which determines the reliability of the reading of O2 concentration. In order to validate the O2 composition of the feed gas to be 21 mol%, the third step is to measure the composition of the feed gas using the O2 analyzer and then calculate the composition of permeate gas through the mass balance. In this study, the composition of permeate gas was not measured directly by using the O2 analyzer because the permeate flow rate was so small that a much larger error may be introduced during the measurement. The tubing of the feed gas was connected directly to the inlet of mass flow controller (1) as illustrated in Figure B.1, and the composition of the feed gas was measured similarly to test of the retentate gas. 243 The last step was that the apparent permeance of each species in the O2/N2 mixed gas was calculated based on one set of differential equations developed by Wang et al. [18], in which the non-ideal gas behavior and pressure drop inside the hollow fiber have been considered. In the case of negligible permeate gas pressure, the selectivity of hollow fiber membranes for a mixed gas was equal to the ideal selectivity; that is, it can be calculated from the ratio of multicomponent permeances measured at the partial pressure [1, 11, 20]. B.3 RESULTS AND DISCUSSION The performance of this new testing system is evaluated by measuring the permeance of two types of hollow fiber membranes in the mixed gas. Their pure gas permeance was first measured using the similar technique described in Jones and Koros’ paper [16]. The O2/N2 separation results of mixed gas and pure gas are listed in Table B.2. It can be found that both permeance and selectivity of mixed gas are very close to those of pure gas when considering the effect of different testing temperatures. The results demonstrate that the new testing system devised in this work can effectively determine the permeance and selectivity of hollow fiber membranes in the separation of O2/N2 mixed gas. The total price of apparatus applied in this new testing system including one oxygen analyzer, two mass flow controllers and one bubble flow meter is no more than S$10,000 (about US$6,000) which is much lower than that of a GC system. 244 Table B.2: Comparison of separation performance of hollow fiber membranes between the O2/N2 mixed gas and pure gas measurements Membrane name Pure gas at 35oC Mixed gas (21 mol%±1% O2 in air) at 24oC Total feed Permeance (GPU) Selectivity (O2/N2) pressure (psig) O2 N2 Permeance (GPU) O2 N2 Ideal selectivity (O2/N2) Hollow fiber 200 0.0631 0.00918 6.9 0.0741 0.0114 6.5 Hollow fiber 200 0.271 6.4 0.306 6.2 0.0423 0.0493 Pure O2 and N2 gases were tested at 132psig. In order to further prove the authenticity of O2/N2 mixed gas permeation results measured by the O2 analyzer, the same hollow fiber samples were used to separate the CO2/CH4 (50/50 mol%) mixture in this study. The testing procedure was similar to that applied in the mixed O2/N2 separation and the only difference is that the composition of CO2/CH4 mixed gas was determined by GC instead of the O2 analyzer. Both O2 analyzer-based testing system and GC-based testing system use the mass flow controller or bubble flow meter to measure the gas flow rate, therefore, the error of these two testing systems should be comparable and is mainly determined by the accuracy of mass flow controller. Experimental conditions and parameters can be found in Table B.1. CO2/CH4 separation results of mixed gas and pure gas are given in Table B.3. It can be seen that the difference between mixed gas and pure gas is almost negligible if considering the effect of different testing temperatures, which again justify that this new testing system with the much lower cost can fulfill the purpose to 245 measure O2/N2 mixed gas separation performance through the hollow fiber membranes. Table B.3: Comparison of separation performance of hollow fiber membranes between the CO2/CH4 mixed gas and pure gas measurements Membrane name Mixed gas (50/50 mol% CO2/CH4) at 24oC Total feed Permeance (GPU) Selectivity (CO2/CH4) pressure (psig) CO2 CH4 Pure gas at 35oC Permeance (GPU) CO2 CH4 Ideal selectivity (CO2/CH4) Hollow fiber 190 0.164 0.00485 33.8 0.187 0.00641 29.2 Hollow fiber 200 0.807 0.0249 32.4 0.835 0.0267 31.2 Pure CO2 and CH4 gases were tested at 100psig. B.4 CONCLUSIONS A new economical testing system using an oxygen analyzer has been designed to determine the permeance and selectivity of hollow fiber membranes in the O2/N2 mixed gas separation. Two types of hollow fiber membranes are used to evaluate the performance of this new testing system. 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Guo, The effects of flow angle and shear rate within the spinneret on the separation performance of poly(ethersulfone) (PES) ultrafiltration hollow fiber membranes, J. Membr. Sci., 240 (2004) 67. 248 [16] C.W. Jones, W.J. Koros, Carbon molecular sieve gas separation membrane. 1. Preparation and characterization based on polyimide precursors, Carbon, 32 (8) (1994) 1419. [17] M.H. Hassan, J.D. Way, P.M. Thoen, A.C. Dillon, Single component and mixed gas transport in a silica hollow fiber membrane, J. Membr. Sci., 104 (1995) 27. [18] R. Wang, S.L. Liu, T.T. Lin, T.S. Chung, Characterization of hollow fiber membranes in a permeator using binary gas mixtures, Chem. Eng. Sci., 57 (2002) 967. [19] C. Cao, R. Wang, T.S. Chung, Y. Liu, Formation of high-performance 6FDA2,6-DAT asymmetric composite hollow fiber membranes for CO2/CH4 separation, J. Membr. Sci., 209 (2002) 309. [20] P.S. Tin, T.S. Chung, Y. Liu, R. Wang, S.L. Liu, K.P. Pramoda, Effects of crosslinking modification on gas separation performance of Matrimid membranes, J. Membr. Sci., 225 (2003) 77. 249 PUBLICATIONS Journal Papers: 1. T.S. Chung, L.Y. Jiang, Y. Li, S. Kulprathipanja, Mixed matrix membranes (MMMs) comprising organic polymers with dispersed inorganic fillers for gas separation, Progress in Polymer Science, in press. 2. Y. Li, T.S. Chung, S. Kulprathipanja, Novel Ag+-zeolite/polymer mixed matrix membranes with a high CO2/CH4 selectivity, AIChE Journal, in press. 3. Y. Li, L.Y. Jiang, T.S. Chung, A new testing system to determine the O2/N2 mixed gas permeation through hollow fiber membranes with an oxygen analyzer, Industrial & Engineering Chemistry Research, 45 (2006) 871. 4. Y. Li, T.S. Chung, Z. Huang, S. Kulprathipanja, Dual-layer polyethersulfone (PES)/BTDA-TDI/MDI co-polyimide (P84) hollow fiber membranes with a submicron PES-zeolite Beta mixed matrix dense-selective layer for gas separation, Journal of Membrane Science, 277 (2006) 28. 5. Y. Li, H.M. Guan, T.S. Chung, S. Kulprathipanja, Effects of novel silane modification of zeolite surface on polymer chain rigidification and partial pore blockage in polyethersulfone (PES)-zeolite A mixed matrix membranes, Journal of Membrane Science, 275 (2006) 17. 250 6. Y. Li, T.S. Chung, C. Cao, S. Kulprathipanja, The effects of polymer chain rigidification, zeolite pore size and pore blockage on polyethersulfone (PES)zeolite A mixed matrix membranes, Journal of Membrane Science, 260 (2005) 45. 7. Y. Li, C. Cao, T.S. Chung, K.P. Pramoda, Fabrication of dual-layer polyethersulfone (PES) hollow fiber membranes with an ultrathin dense selective layer for gas separation, Journal of Membrane Science, 245 (2004) 53. 8. Y. Li, Y.D. Wang, Y.X. Li, Y.Y. Dai, Extraction of glyoxylic acid, glycolic acid, acrylic acid, and benzoic acid with trialkylphosphine oxide, Journal of Chemical and Engineering Data, 48 (2003) 621. 9. Y.D. Wang, Y. Li, Y.X. Li, Y.Y. Dai, Liquid-liquid extraction of carboxylic acid with trialkylphosphine oxide, Chemical Engineering (China), 31 (6) (2003) 8. 10. Y.D. Wang, Y.X. Li, Y. Li, J.Y. Wang, Z.Y. Li, Y.Y. Dai, Extraction equilibria of monocarboxylic acids with trialkylphosphine oxide, Journal of Chemical and Engineering Data, 46 (2001) 831. Conference Papers: 1. Y. Li, P.S. Tin, T.S. Chung, S. Kulprathipanja, A novel ion exchange treatment of zeolite for the application of mixed matrix membranes in natural and hydrocarbon separation, presented in AIChE Annual Meeting 2006, San Francisco, California, USA, Nov 12-17 2006. 251 2. T.S. Chung, L.Y. Jiang, Y. Li, S. Kulprathipanja, Fabrication and characterization of zeolite/polymer mixed matrix nano-composite hollow fiber membranes, presented in the Third Conference of Aseanian Membrane Society, Beijing, China, August 23-25, 2006. 3. T.S. Chung, L.Y. Jiang, Y. Li, P.S. Tin, S. Kulprathipanja, Fabrication of polymer/zeolite and carbon/zeolite mixed matrix membranes for gas separation, presented in the 17th Annual Meeting of the North American Membrane Society (NAMS), Chicago, Illinois, USA, May 12-17, 2006. 4. Y. Li, T.S. Chung, S. Kulprathipanja, Enhanced gas separation performance in polyethersulfone (PES)-modified zeolite mixed matrix membranes, presented in AIChE Annual Meeting 2005, Cincinnati, OH, USA, Oct 30-Nov 04 2005. 5. T.S. Chung, L.Y. Jiang, Y. Li, S. Kulprathipanja, Fabrication and characterization of zeolite/polymer mixed matrix nano-composite hollow fiber membranes, presented in AIChE Annual Meeting 2005, Cincinnati, OH, USA, Oct 30-Nov 04 2005. 6. T.S. Chung, L.Y. Jiang, Y. Li, S. Kulprathipanja, Fundamental understanding of the science and engineering of the fabrication of zeolite/polymer nano-composite, presented in the 4th International Membrane Conference on Membrane Science and Technology, Chung-Li, Taiwan, Aug 18-19, 2005. 7. Y. Li, T.S. Chung, S. Kulprathipanja, Enhanced gas separation performance in polyethersulfone (PES)-zeolite mixed matrix membranes, presented in the 16th 252 Annual Meeting of the North American Membrane Society (NAMS), Providence, Rhode Island, USA, Jun 11-15, 2005. 8. T.S. Chung, D.F. Li, L.Y. Jiang, Y. Li, S. Kulprathipanja, Morphological and structure control of dual-layer hollow fiber membranes formed by a phaseinversion co-extrusion approach, presented in the 16th Annual Meeting of the North American Membrane Society (NAMS), Providence, Rhode Island, USA, June 11-15, 2005. 9. Y.D. Wang, Y.X. Li, Y. Li, J.Y. Wang, Extraction equilibrium of acetic acid and its derivatives by Cyanex 923, presented in the Third Joint China/USA Chemical Engineering Conference, Beijing, China, 2000, 07-049-053. Patents: 1. Y. Li, P.S. Tin, T.S. Chung, S. Kulprathipanja, Ion exchange treatment of zeolites for the application of mixed matrix membranes for natural gas and hydrocarbon separation, US. Patent US60/792,094 (2006). 2. H.M. Guan, Y. Li, T.S. Chung, S. Kulprathipanja, Chemical modification of zeolite surface for mixed matrix membrane, US. Patent US60/695,097 (2005). 253 [...]... Change of glass transition temperatures of dual-layer hollow fiber membranes with the mixed matrix outer layer over neat PES dense film…………………………………………………………………205 Table 7.6 Effects of air gap on the gas separation performance of dual-layer PES/P84 hollow fiber membranes with a mixed matrix outer layer after heat-treated at 235oC………………….…………………… 207 Table 7.7 Comparison of pure gas and mixed gas separation. .. separation performance of dual-layer PES/P84 hollow fiber membranes with a mixed matrix outer layer…………….…………………………………………….208 Table B.1 Module specifications and experimental conditions (24°C)……….239 Table B.2 Comparison of separation performance of hollow fiber membranes between the O2/N2 mixed gas and pure gas measurements……… 245 Table B.3 Comparison of separation performance of hollow fiber membranes. .. spectroscopy XRD X-ray diffraction xxi LIST OF TABLES Table 1.1 Scientific developments of membrane gas transport… …………… 5 Table 1.2 Industrial applications of gas separation membranes. ……… … … 8 Table 1.3 Size of materials retained, driving force and type of membrane used for each separation process… …………………………………… 15 Table 1.4 Examples of membrane applications and alternative separation processes……………………………………………………………... parameters of dual-layer PES hollow fiber membranes 119 Table 4.2 Gas separation performances of dual-layer PES hollow fiber membranes with different post-treatment protocols……… …… 120 Table 5.1 Change of O2 and N2 permeability in different regions of PES-zeolite 4A mixed matrix membranes. …………………………………… 144 Table 5.2 Change of glass transition temperatures of mixed matrix membranes over pure PES dense film……………………... PES/P84 hollow fiber membranes with a mixed matrix outer layer.………… … 197 Table 7.3 The effects of heat-treatment temperature on the gas separation performance of DL2A dual-layer PES/P84 hollow fiber membranes xxiii with a mixed matrix outer layer……………………………… … 200 Table 7.4 Gas separation performance of dual-layer PES/P84 hollow fiber membranes with different mixed matrix outer layer thicknesses after heat-treated... Volume fraction of the rigidified polymer region in the total mixed matrix membrane vz Axial velocity z The axial distance αA/B Ideal selectivity of component A over B αD i,j Ideal selectivity of a gas pair for diffusivity α* i,j Ideal selectivity of a gas pair for permeability αS i,j Ideal selectivity of a gas pair for solubility β Polymer chain immobilization factor in mixed matrix membranes β’ Permeability... resultant materials may potentially offer superior performance in terms of the permeability and permselectivity for gas/ liquid separation The purpose of this work is to evaluate the combined use of commercially available polyethersulfone (PES) as a matrix and various zeolites as a dispersive phase, and to prepare the high-performance mixed matrix membranes (MMMs) for gas separation A comprehensive research... (PES)-Zeolite A Mixed Matrix Membranes ……………… …….221 8.1.4 Dual-layer Polyethersulfone (PES)/BTDA-TDI/MDI Co-polyimide (P84) Hollow Fiber Membranes with a Submicron PES-Zeolite Beta Mixed Matrix Dense-Selective Layer for Gas Separation ……… 222 8.2 Recommendations for Future Work………………………………………….223 8.2.1 Flat Dense Polymer-Zeolite Mixed Matrix Membranes ………… 223 8.2.2 Dual-layer Hollow Fibers with a Mixed Matrix. .. Schematic diagram of gas permeation testing apparatus for the mixed matrix hollow fibers………………………………………106 Figure 3.9 Apparatus of the mixed gas permeation test in neat polymeric hollow fibers…………………………………………………… 108 Figure 3.10 Schematic diagram of mixed gas permeation test apparatus for flat dense membranes …………………………………….… ……111 Figure 4.1 Integrity of as-spun dual-layer hollow fiber membranes (A: Overall... zeolite Beta for the particle size determination………………… 233 Figure B.1 Schematic diagram of apparatus using an oxygen analyzer for O2/N2 mixed gas permeation tests through a hollow fiber module….… 238 xxxi CHAPTER ONE INTRODUCTION OF GAS SEPARATION MEMBRANE The separation of one or more gases from complex multicomponent mixture of gases is necessary in a large number of industries Such separations currently . DEVELOPMENT OF MIXED MATRIX MEMBRANES FOR GAS SEPARATION APPLICATION LI YI (M. Eng., Tsinghua University, P. R. China) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY. and Organization of Dissertation……………………… 37 1.8 References…………………………………………………………………… 41 CHAPTER 2 MIXED MATRIX MEMBRANES FOR GAS SEPARATION 48 2.1 Emergence of Mixed Matrix Membranes …………………………………. 2.1.3 Mixed Matrix Membranes (MMMs)………………………………… 57 2.2 Development of Mixed Matrix Membrane………………………………… 58 v 2.2.1 Flat Dense Mixed Matrix Membranes …………… ….……………58 2.2.2 Hollow Fiber Mixed