Luận án tiến sĩ: Tách CO2 H2S và mô hình WGS Membrane Reactor
Luận án tiến sĩ công nghệ tách CO2 và H2S bằng màng polymer. Mô hình WGS membrane reactor cho pin nhiên liệu đạt nồng độ CO2 >98% và khôi phục H2 >97%.
The Ohio State University
Chemical Engineering
Luan An
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I. CO2 H2S Membrane Separations Technology Overview
Acid gas removal represents a critical challenge in environmental and energy processes. Traditional commercial technologies consume substantial energy and require significant infrastructure. Membrane-based CO2 and H2S capture offers transformative advantages. These systems demand less energy. Installation and operation remain simple. Process flexibility exceeds conventional methods. Weight and space requirements drop dramatically.
The technology faces limitations in large-scale applications. Transport properties remain relatively low compared to established methods. Recent advances in polymeric membranes address these constraints. Facilitated transport mechanisms enable breakthrough performance. CO2-selective membranes achieve permeability above 2000 Barrers. Selectivity ratios exceed 40 for CO2/H2 and 200 for CO2/N2 at operating temperatures of 100-150°C.
H2S removal demonstrates even superior characteristics. Higher reaction rates and smaller molecular size contribute to enhanced performance. H2S permeability surpasses CO2 values by threefold. H2S/H2 selectivity shows similar improvement ratios. These membrane separation technology advances enable practical deployment across multiple industries. Applications span from flue gas treatment to natural gas purification. The selective separation capability transforms acid gas removal economics.
1.1. Facilitated Transport Mechanism Benefits
Facilitated transport distinguishes advanced membranes from conventional barriers. Chemical carriers within the membrane matrix react reversibly with target gases. This mechanism accelerates transport while maintaining selectivity. Both CO2 and H2S exhibit facilitated effects in polymer membranes. The carrier-mediated process enhances membrane permeability substantially. Selectivity increases simultaneously through preferential chemical interaction.
1.2. Performance Metrics and Operating Conditions
Operating temperature ranges from 100 to 150°C for optimal performance. CO2 permeability exceeds 2000 Barrers under these conditions. CO2/H2 selectivity maintains values greater than 40. CO2/N2 selectivity surpasses 200 consistently. H2S demonstrates approximately triple the performance of CO2. These metrics position the technology competitively against established gas separation technology methods.
1.3. Comparative Advantages Over Traditional Methods
Energy consumption decreases significantly compared to amine scrubbing systems. Equipment footprint reduces by substantial margins. Installation complexity drops dramatically. Operational flexibility allows rapid response to process variations. Maintenance requirements remain minimal. Capital costs trend lower for moderate-scale applications. These advantages drive adoption in carbon capture and syngas purification applications.
II. CO2 Capture Applications in Industrial Processes
CO2 capture from flue gas and natural gas represents major industrial applications. Experimental results demonstrate exceptional separation performance. Using steam as sweep gas, permeate CO2 concentration exceeds 98% on dry basis. This purity level meets stringent requirements for carbon capture and sequestration. The membrane system processes gas mixtures containing N2 and H2 effectively.
Natural gas purification presents different challenges. Feed pressures reach 500 psia in typical operations. The membrane maintains decent CO2 transport properties under these elevated pressures. Methane recovery remains high while CO2 removal meets pipeline specifications. Thin-film composite membrane structures enhance performance dramatically. Selective layer thickness reduction increases CO2 flux proportionally. This architectural approach optimizes the balance between selectivity and productivity.
The ceramic membranes and polymer membranes each offer distinct advantages. Polymer systems excel in moderate temperature applications. Ceramic alternatives withstand higher temperatures and aggressive chemical environments. Material selection depends on specific process conditions. Both membrane types benefit from facilitated transport mechanisms. The technology scales effectively from laboratory to industrial installations. Economic viability improves with increasing production volumes.
2.1. Flue Gas CO2 Removal Performance
Flue gas applications target post-combustion carbon capture. Steam sweep gas enables high CO2 concentration in permeate stream. Dry basis purity exceeds 98% consistently. The system handles typical flue gas components including N2, O2, and water vapor. Membrane permeability remains stable across extended operating periods. Selective separation of CO2 from nitrogen proves highly effective.
2.2. Natural Gas Sweetening Operations
Natural gas contains CO2 and H2S as primary acid gas contaminants. Removal requirements vary based on pipeline specifications and end-use applications. The membrane system operates effectively at pressures up to 500 psia. CO2/CH4 separation maintains adequate selectivity under pressure. Transport properties remain acceptable across the operating pressure range. Acid gas removal meets commercial standards for natural gas quality.
2.3. Thin Film Composite Membrane Architecture
Composite membrane structure separates mechanical support from selective transport. Thin selective layers minimize mass transfer resistance. Support layers provide mechanical strength and chemical resistance. Decreasing selective layer thickness increases CO2 flux significantly. Optimization balances flux enhancement against selectivity maintenance. Manufacturing techniques enable precise thickness control in production.
III. Water Gas Shift Membrane Reactor Technology
CO2-selective water gas shift membrane reactors advance hydrogen production technology. The system combines catalytic reaction with membrane separation. Continuous CO2 removal shifts equilibrium forward. This approach enhances CO conversion beyond thermodynamic limitations. Hydrogen purity increases while operating temperatures decrease compared to conventional reactors.
Countercurrent flow configuration optimizes driving forces throughout the reactor. Feed gas enters opposite to sweep gas flow. This arrangement maintains concentration gradients along the reactor length. One-dimensional non-isothermal modeling predicts system performance accurately. Temperature profiles reflect exothermic reaction heat release and transport phenomena. The model accounts for simultaneous reaction and separation processes.
Performance targets challenge conventional WGS technology. CO concentration below 10 ppm becomes achievable from reforming syngases. Hydrogen recovery exceeds 97% in optimized configurations. These metrics satisfy fuel cell feed requirements directly. The water gas shift reaction proceeds efficiently at moderate temperatures. Process pressure maintenance eliminates compression energy penalties. Syngas purification occurs in a single integrated unit operation.
3.1. Equilibrium Shift Through CO2 Removal
Reversible WGS reaction faces equilibrium limitations in conventional reactors. Continuous CO2 removal drives reaction forward beyond equilibrium conversion. Le Chatelier's principle explains this enhancement mechanism. Product removal reduces CO concentration to parts-per-million levels. The membrane provides selective CO2 permeation while retaining hydrogen. Reaction proceeds continuously as CO2 exits the system.
3.2. Countercurrent Reactor Configuration Benefits
Countercurrent flow maximizes concentration driving forces. Feed gas contacts sweep gas with lowest CO2 content. Permeate exit contacts feed with highest CO2 concentration. This arrangement optimizes membrane utilization efficiency. Temperature profiles develop naturally from reaction exotherm and heat transfer. The configuration enables compact reactor design with high performance.
3.3. Modeling and Experimental Validation
One-dimensional non-isothermal model captures essential physics. Reaction kinetics, mass transfer, and heat transfer couple in the simulation. Model predictions agree well with experimental measurements. CO concentration drops below 10 ppm as predicted. Hydrogen recovery matches modeling results closely. The validated model enables scale-up design and optimization studies.
IV. Hydrogen Production for Fuel Cell Applications
Fuel cell systems demand ultra-pure hydrogen with minimal CO content. Even trace CO levels poison fuel cell catalysts. Traditional hydrogen production requires multiple purification steps. WGS membrane reactors integrate reaction and purification in single equipment. This integration reduces capital costs and operational complexity. Process intensification improves overall system efficiency.
Reforming syngases contain CO, CO2, H2, and water vapor. The membrane reactor processes this mixture directly. CO oxidation through water gas shift reaction produces additional hydrogen. Simultaneous CO2 removal prevents reverse reaction. The permeate stream carries concentrated CO2 for capture or utilization. Retentate stream contains purified hydrogen at process pressure.
Hydrogen production efficiency impacts fuel cell system economics significantly. Recovery rates above 97% minimize hydrogen losses. CO levels below 10 ppm eliminate downstream purification requirements. The membrane reactor operates at moderate temperatures between 100-150°C. This temperature range suits integration with fuel processors. Energy efficiency exceeds conventional multi-step purification trains. The technology enables compact, efficient fuel cell hydrogen processing systems.
4.1. Fuel Cell Hydrogen Purity Requirements
Proton exchange membrane fuel cells tolerate minimal CO contamination. CO concentrations must remain below 10-50 ppm depending on cell design. Higher CO levels adsorb on platinum catalysts irreversibly. Cell performance degrades rapidly with catalyst poisoning. Hydrogen purity specifications typically exceed 99.95%. The membrane reactor meets these stringent requirements directly without additional purification.
4.2. Integration with Fuel Processing Systems
Fuel processors convert hydrocarbon fuels to hydrogen-rich gas. Steam reforming or partial oxidation produces syngas. The membrane reactor follows reforming operations directly. Operating temperature compatibility enables thermal integration. Heat recovery between process streams improves efficiency. The integrated system reduces equipment count and footprint substantially.
4.3. Process Efficiency and Economic Advantages
Single-step purification eliminates multiple separation units. Capital costs decrease compared to conventional approaches. Operating costs benefit from reduced energy consumption. Hydrogen recovery above 97% minimizes fuel waste. Process pressure maintenance avoids compression energy penalties. Economic analysis favors membrane reactor technology for distributed hydrogen production applications.
V. Membrane Material Science and Performance
Polymeric membranes dominate moderate temperature gas separation applications. Material selection balances permeability, selectivity, and stability. Facilitated transport membranes incorporate chemical carriers within polymer matrices. These carriers react reversibly with target gas molecules. The reaction-diffusion mechanism enhances both transport rate and selectivity.
Polymer membrane composition determines performance characteristics. Hydrophilic polymers support aqueous carrier solutions. Carrier concentration affects both permeability and selectivity. Optimization requires balancing multiple competing factors. Membrane thickness inversely affects flux while supporting mechanical integrity. Composite structures separate these functions into distinct layers.
Ceramic membranes offer advantages for high-temperature applications. Thermal stability exceeds polymer capabilities significantly. Chemical resistance withstands aggressive process environments. Manufacturing costs remain higher than polymer alternatives. Membrane permeability typically runs lower than facilitated transport polymers. Application selection depends on specific process requirements. Both material classes contribute to advancing gas separation technology across diverse applications.
5.1. Facilitated Transport Carrier Chemistry
Chemical carriers enable selective gas transport through reversible reactions. Carbonate and bicarbonate systems facilitate CO2 transport effectively. Amine-based carriers show high reactivity with acid gases. Carrier mobility within polymer matrix affects overall permeability. Reaction kinetics must exceed diffusion rates for facilitation. Carrier concentration optimization balances performance against physical properties.
5.2. Polymer Matrix Selection Criteria
Polymer selection considers chemical compatibility with carriers and process gases. Hydrophilic polymers accommodate aqueous carrier solutions. Glass transition temperature affects operating temperature range. Mechanical properties ensure membrane integrity under pressure differentials. Chemical stability prevents degradation during extended operation. Commercial availability and cost influence practical implementation decisions.
5.3. Ceramic Membrane Characteristics
Ceramic membranes withstand temperatures exceeding 500°C routinely. Chemical inertness provides stability in corrosive environments. Pore size distribution determines separation selectivity mechanisms. Surface modification enhances selective transport properties. Manufacturing complexity increases production costs. Applications justify premium costs through superior durability and performance under extreme conditions.
VI. Future Developments in Membrane Separation
Membrane separation technology continues advancing through materials innovation and process optimization. Emerging polymer chemistries promise enhanced performance characteristics. Nanocomposite membranes incorporate inorganic fillers for property enhancement. Mixed matrix membranes combine polymer and ceramic advantages. These hybrid approaches target performance gaps in current technologies.
Manufacturing scale-up remains critical for commercial deployment. Thin-film composite production requires precise process control. Defect-free selective layers determine actual separation performance. Quality assurance protocols ensure consistent membrane properties. Cost reduction through manufacturing optimization enables broader market penetration. Automation and continuous production methods improve economics substantially.
Application expansion drives technology development priorities. Carbon capture from power generation represents massive potential markets. Biogas upgrading offers distributed renewable energy applications. Hydrogen production supports emerging fuel cell and chemical industries. Syngas purification enables cleaner chemical synthesis routes. Each application presents unique technical and economic requirements. Membrane technology flexibility allows customization for specific process conditions. Continued research and development will expand capabilities and reduce costs across all application areas.
6.1. Advanced Membrane Materials Development
Nanocomposite membranes incorporate nanoparticles into polymer matrices. These additives enhance mechanical properties and thermal stability. Selective transport can improve through preferential pathway creation. Mixed matrix membranes combine polymer processability with ceramic performance. Research focuses on optimizing filler loading and dispersion. Novel polymer chemistries target higher intrinsic permeability and selectivity.
6.2. Manufacturing and Scale Up Challenges
Large-scale production requires reproducible coating processes. Defect density must remain minimal for commercial viability. Automated inspection systems detect membrane imperfections. Process control ensures consistent selective layer thickness. Module fabrication techniques affect overall system performance. Cost reduction through manufacturing improvements remains a primary objective.
6.3. Emerging Application Opportunities
Post-combustion carbon capture addresses climate change mitigation. Biogas upgrading converts waste to pipeline-quality renewable natural gas. Hydrogen production supports clean energy transition strategies. Syngas purification enables sustainable chemical manufacturing. Each application requires optimized membrane properties and system configurations. Market growth drives continued technology investment and innovation.
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Tải xuống để đọc toàn bộCO2 (H2S) MEMBRANE SEPARATIONS AND WGS MEMBRANE REACTOR MODELING FOR FUEL CELLS DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy In the Graduate School of the Ohio State University By Jin Huang, M. ***** The Ohio State University 2007 Dissertation Committee: Approved by Professor W. Winston Ho, Advisor Professor L. James Lee _____________________________________________________________________________ _ Advisor Professor Kurt W.
Koelling Graduate program in Chemical Engineering UMI Number: 3241691 UMI Microform 3241691 Copyright 2007 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.
Box 1346 Ann Arbor, MI 48106-1346 ABSTRACT Acid-gas removal is of great importance in many environmental or energy-related processes. Compared to current commercial technologies, membrane-based CO2 and H2S capture has the advantages of low energy consumption, low weight and space requirement, simplicity of installation / operation, and high process flexibility. However, the large-scale application of the membrane separation technology is limited by the relatively low transport properties. In this study, CO2 (H2S)-selective polymeric membranes with high permeability and high selectivity have been studied based on the facilitated transport mechanism.
The membrane showed facilitated effect for both CO2 and H2S. A CO2 permeability of above 2000 Barrers, a CO2/H2 selectivity of greater than 40, and a CO2/N2 selectivity of greater than 200 at 100 – 150oC were observed. As a result of higher reaction rate and smaller diffusing compound, the H2S permeability and H2S/H2 selectivity were about three times higher than those properties for CO2. The novel CO2-selective membrane has been applied to capture CO2 from flue gas and natural gas.
In the CO2 capture experiments from a gas mixture with N2 and H2, a permeate CO2 dry concentration of greater than 98% was obtained by using steam as the sweep gas. In CO2/CH4 separation, decent CO2 transport properties were obtained with a feed pressure up to 500 psia. With the thin-film composite membrane structure, significant increase on the CO2 flux was achieved with the decrease of the selective layer thickness. ii With the continuous removal of CO2, CO2-selective water-gas-shift (WGS) membrane reactor is a promising approach to enhance CO conversion and increase the purity of H2 at process pressure under relatively low temperature.
The simultaneous reaction and transport process in the countercurrent WGS membrane reactor was simulated by using a one-dimensional non-isothermal model. The modeling results show that a CO concentration of less than 10 ppm and a H2 recovery of greater than 97% are achievable from reforming syngases. In an experimental study, the reversible WGS was shifted forward by removing CO2 so that the CO concentration was significantly decreased to less than 10 ppm. The modeling results agreed well with the experimental data.
iii Dedicated to my parents, my brother and Yujun for their love and support iv ACKNOWLEDGMENTS I would like to thank the following people for their help and support in conducting this research: • Dr. Winston Ho, my advisor at Ohio State, for his thoughtful guidance, enthusiastic discussion and continuous support and encouragement throughout the five years I have been in the United States. His persistence in pursuing the truth and his hard-working attitude have been, and will be, inspiring my career and life in the past and in the future. James Lee, Dr.
David Tomasko, and Dr. Barbara Wyslouzil for all their constructive critiques which helped me to improve my work. • I thank all my colleagues in Dr. Ho’s group: He Bai, Philip Chang, Bishnupada Mandal, Michael Vilt, Chi Yen, Jian Zou, and fellow students in Koffolt Labs who have to remain unnamed here.
Also I would like to thank the following people: • My friends, both in US and China, for all their encouragements and friendship. • My parents and my brother for their support and love throughout my studies over the years. v • Yujun for her support, encouragements, patience, and love while writing this thesis. vi VITA April 19, 1977.Born in Jianli, Hubei, China 1996.
Organic Chemical Technology, Wuhan Institute of Chemical Technology, Wuhan, China 1999. Chemical Engineering, East China Univ. of Science & Technology, Shanghai, China 2001 – 2002 .Graduate Research Associate, University of Kentucky, Lexington, KY, USA 2002 – 2006.Graduate Research Associate, The Ohio State University, Columbus, OH, USA PUBLICATIONS 1. Jin Huang, Louei El-Azzami, and W.
Winston Ho, “Modeling of CO2-selective Water- Gas-Shift Membrane Reactor for Fuel Cell,” J. Jian Zou, Jin Huang, and W. Winston Ho, “CO2-Selective Water gas shift Membrane Reactors for Fuel Cell Hydrogen Processing,” accepted by Ind. Ruofei Zhao, Jin Huang, Bin Sun, and Gance Dai, “A Study of Mechanical Properties of Mica Filled Polypropylene Based GMT Composites,” J.
Hui-ling Lu, Jin Huang, and Gance Dai, “Effects of Processing Parameters on Melt Impregnation of GMT Sheets,” J. East China Univ. Ming Li, Jin Huang, and Gance Dai, “Melt Flow through Glass Fiber Mat during GMT Melt Impregnation,” Acta Materiae Compositae Sinica, 17(3), pp. FIELDS OF STUDY Major Field: Chemical Engineering viii TABLE OF CONTENTS Abstract……………………………………………….vii List of Tables………………………….xiii List of Figures………………………………………………………………….xiv List of Notations……………………………………………………………….1 Membrane Separation Technology…………….2 Acid-gas Removal…………….3 Scope and Objectives of Research……………………………………………….
Synthesis of CO2 (H2S)-Selective Membrane……………….1 Polymeric Membrane for Gas Separation………………………………….2 Reaction Mechanism between Amines and Acid Gases………………….3 Facilitated Transport Membrane for Acid-gas Removal………………….2 CO2 (H2S)-Selective Membrane……….1 Membrane Synthesis and Characterization……………………………….3 CO2 Transport Properties…………………………………………………. Flue Gas CO2 Removal….2 CO2 Capture Experiments……………………………………………………….4 Results and Discussion………………………………………….1 Transport Properties of CO2-selective Membrane ……………………….2 CO2 Removal Capacity…………………………………………………….3 CO2 Capture Performance.1 Effect of Feed Inlet Flow Rate……………………………………….2 Effect of Sweep-to-Feed Ratio………………………………………. High-Pressure CO2 and H2S Removal from Natural Gas.3 Results and Discussion………………………………………………………….1 Free-Standing Membrane………………………………………………….1 Effect of Feed Pressure on CO2 Transport Properties……………….2 Effect of Temperature on CO2 Transport Properties…………….3 Effect of Permeate Pressure on CO2 Transport Properties………….2 Thin-Film Composite Membrane………………………………………….1 Effect of Membrane Thickness on CO2 Transport Properties….2 Effect of Temperature on CO2 and H2S Transport Properties………. Other CO2-Selective Membranes…………………………………………………….2 Hybrid Facilitated Transport Membrane………………………….1 Synthesis of Hybrid Membrane………………………………………….2 Results and Discussion………………………………………………….3 Segmented Polyimide Copolymer…………………………………………….1 Membrane Synthesis and Testing……………………………………….2 Results and Discussion………………………………………………….
Modeling of CO2-selective WGS membrane reactor for fuel cells.3 Experimental Study of CO2-Selective WGS Membrane Reactor …………….4 Results and Discussion…………………………………………………………130 6.1 Autothermal Reforming Syngas………………………………………….2 Effect of CO2/H2 Selectivity……………………………………….3 Effect of CO2 Permeability…………………………………………133 6.4 Effect of Sweep-to-Feed Ratio…………………………………….5 Effect of Inlet Feed Temperature………………………………….6 Effect of Inlet Sweep Temperature…………………………………135 6.7 Effect of Feed-Side Pressure……………………………………….8 Effect of Inlet Feed CO Concentration…………………………….9 Effect of Catalyst Activity………………………………………….2 Steam Reforming Syngas…………………………………………………138 6.2 Effect of CO2/H2 Selectivity……………………………………….3 Effect of CO2 Permeability…………………………………………140 6.4 Effect of Sweep-to-Feed Ratio…………………………………….5 Effect of Inlet Feed Temperature………………………………….6 Effect of Inlet Sweep Temperature…………………………………142 6.7 Effect of Feed-Side Pressure……………………………………….8 Effect of Feed Inlet CO Concentration…………………………….9 Effect of Catalyst Activity………………………………………….3 Membrane Reactor Results………………………………………………. Conclusions and recommendations………………………………………………….1 CO2 (H2S)-selective polymeric membranes and applications………………….2 Recommendations for Future Work…………………………………………….182 Bibliography……………………………………………………………………………185 xii LIST OF TABLES Table Page 2.1 Carbamate stability constants for different amines at 40oC by carbon-13 NMR (Sartori and Savage, 1983) ………………………………………………………30 3.1 The operating parameters for the CO2 capture experiments…………………….1 Diols as the option of soft segment…………………………………………….2 The testing results of copolymer membrane……………………………………109 6.1 The compositions of autothermal reforming syngas and steam reforming syngas………………………………………………………………………….147 xiii LIST OF FIGURES Figure Page 2.1 Facilitated transport mechanism…………………………………………………31 2.2 Synthesis of the crosslinked PVA with formaldehyde.3 Chemical structures of (a) free polyallylamine and (b) AIBA-K……………….4 Schematic of the gas permeation unit……………………………………………34 2.5 Scanning electron microscopic picture of the membrane synthesized………………35 2.6 CO2 permeability vs.7 CO2/H2 selectivity vs.8 CO2/N2 selectivity vs.9 H2S and CO2 permeability vs.10 H2S/H2 and CO2/H2 selectivity vs.11 H2S removal capacity with the circular gas permeation cell (24.1 Schematic of the hollow-fiber membrane module……………………………….2 Schematic of gas separation with the CO2-selective membrane…………………….3 Exit dry CO2 concentration in the retentate vs. feed flow rate………………….4 Permeate CO2 dry concentration and CO2 recovery vs. feed flow rate………….5 Permeate CO2 dry concentration and CO2 recovery vs.
sweep-to-feed molar ratio………………….6 CO2 concentration (wet) profiles along the length of membrane module…….1 Schematic of gas separation with the CO2 (H2S)-selective membrane………….2 CO2 permeability and CO2/CH4 selectivity vs. feed pressure at 106oC………….3 CO2 permeability and CO2/CH4 selectivity vs. feed pressure at 116oC………….4 CO2 permeability and CO2/CH4 selectivity vs. temperature at 150 psia feed pressure………………………………………………………………………….5 CO2 permeability and CO2/CH4 selectivity vs.
temperature at 500 psia feed pressure………………………………………………………………………….6 CO2 permeability and CO2/CH4 selectivity vs. permeate pressure at 106oC and 500 psia feed pressure……………………………………………………………85 4.7 CO2 permeability and CO2/CH4 selectivity vs. permeate pressure at 111oC and 500 psia feed pressure……………………………………………………………86 4.8 CO2 permeability and CO2/CH4 selectivity vs. permeate pressure at 116oC and 500 psia feed pressure……………………………………………………………87 4.9 CO2 permeance and CO2/CH4 selectivity vs.
membrane thickness at 116oC and 150 psia feed pressure……………………………………………………………88 4.10 Total mass transfer resistance, Rt, versus membrane thickness………………….11 CO2/CH4 and H2S/CH4 selectivities versus operating temperature…………….12 CO2 and H2S permeances versus operating temperature……………………….13 Schematic of the phase inversion process with the delayed demixing (■ denotes the top of the liquid film, ● denotes the bottom of the liquid film, and red lines denote the composition path along the liquid film thickness) ………………….14 The weight reduction of the membrane during the air-drying (23oC, casting gap setting = 10 mil) …………………………………………………………………93 4.15 The preliminary data from the asymmetric membranes via the phase inversion process (106oC and 150 psia feed pressure) …………………………………….1 CO2/H2 selectivity of PVA membrane and hybrid PVA membrane……………110 5.2 CO2/N2 selectivity of PVA membrane and hybrid PVA membrane……………111 5.3 CO2 permeability of PVA membrane and hybrid PVA membrane.4 The thermogravimetric curves for the hybrid PVA membrane and the PVA membrane……………………………………….5 Reaction steps in the synthesis of 2 PMDA/ 1 PEA 2000/ 1 MDA….6 FTIR spectra of copolymer, 2 PMDA / 1 PEA 2000 / 1 MDA, after imidization…………………………………………………………………….1 Schematic of water-gas-shift hollow-fiber membrane reactor………………….2 Cross-section schematic of the water-gas-shift membrane reactor…………….3 Feed-side CO and CO2 mole fraction profiles along the length of membrane reactor for autothermal reforming syngas………………………………………150 6.4 Feed-side H2 mole fraction profiles along the length of membrane reactor for autothermal reforming syngas………………………………………………….5 Feed-side and sweep-side temperature profiles along the length of membrane reactor for autothermal reforming syngas………………………………………152 6.6 The effects of CO2/H2 selectivity on feed-side exit CO concentration and H2 recovery for autothermal reforming syngas…………………………………….7 The effect of CO2 permeability on required membrane area for autothermal reforming syngas………………………………………….8 The effects of sweep-to-feed ratio on feed-side exit CO concentration and H2 recovery for autothermal reforming syngas……………………………….9 The effect of inlet feed temperature on required membrane area for autothermal reforming syngas………………………………………………………….10 Feed-side temperature profiles along the length of membrane reactor for autothermal reforming syngas with different inlet feed temperatures……….11 The effect of inlet sweep temperature on required membrane area for autothermal reforming syngas……………………………………………………………….12 Feed-side temperature profiles along the length of membrane reactor for autothermal reforming syngas with different inlet sweep temperatures……….13 The effect of feed-side pressure on required membrane area for autothermal reforming syngas……………………………………………………………….14 Feed-side CO mole fraction profiles along the length of membrane reactor for autothermal reforming syngas with different inlet feed CO temperatures…….15 The effect of catalyst activity on required membrane area for autothermal reforming syngas……………………………………………………………….16 Feed-side CO and CO2 mole fraction profiles along the length of membrane reactor for steam reforming syngas…………………………………………….17 Feed-side H2 mole fraction profiles along the length of membrane reactor for steam reforming syngas……………………………………………………….18 Feed-side and sweep-side temperature profiles along the length of membrane reactor for steam reforming syngas…………………………………………….19 The effects of CO2/H2 selectivity on feed-side exit CO concentration and H2 recovery for steam reforming syngas………………………………………….20 The effect of CO2 permeability on required membrane area for steam reforming syngas………………………………………………………………………….21 The effects of sweep-to-feed ratio on feed-side exit CO concentration and H2 recovery for steam reforming syngas………………………………………….22 The effect of inlet feed temperature on required membrane area for steam reforming syngas……………………………………………………………….23 Feed-side temperature profiles along the length of membrane reactor for steam reforming syngas with different inlet feed temperatures……………………….24 The effect of inlet sweep temperature on required membrane area for steam reforming syngas……………………………………………………………….25 Feed-side temperature profiles along the length of membrane reactor for steam reforming syngas with different inlet sweep temperatures…………………….26 The effect of feed-side pressure on required membrane area for steam reforming syngas………………………………………………………………………….
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Luận án tiến sĩ công nghệ tách CO2 và H2S bằng màng polymer. Mô hình WGS membrane reactor cho pin nhiên liệu đạt nồng độ CO2 >98% và khôi phục H2 >97%.
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