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Eric Favre - One of the best experts on this subject based on the ideXlab platform.
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Status and progress of Membrane Contactors in post-combustion carbon capture: A state-of-the-art review of new developments
Journal of Membrane Science, 2016Co-Authors: Shuaifei Zhao, Paul Hubert Maria Feron, Jingwei Hou, Liyuan Deng, Elodie Chabanon, Eric Favre, Shuiping Yan, Vicki Chen, Hong QiAbstract:Post-combustion carbon capture (PCC), which can be retrofitted to existing units in power plants worldwide, is regarded as the first technologically feasible and effective way to combat human-induced climate change. The Membrane contactor is an emerging and promising Membrane technology for PCC as it integrates the benefits of both liquid absorption (high selectivity) and Membrane separation (modularity and compactness). This review aims to provide a state-of-the-art assessment of the research work carried out so far on Membrane contactor technology in PCC. It details common aspects of Membrane Contactors, such as technological advantages, Membrane wetting, mass transfer and module design, as well as new advances (e.g., new Membranes and absorbents used in absorption processes) and novel applications (e.g., direct CO2 stripping and integrated heat recovery in desorption processes). Moreover, the difference in performance between Membrane absorption and conventional absorption is also compared and discussed. Lastly, we discuss the status and progress of Membrane Contactors in PCC and offer some recommendations for future work. This paper provides a clear overview on the recent developments of Membrane contactor technology in PCC.
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Ammonia based CO2 capture process using hollow fiber Membrane Contactors
Journal of Membrane Science, 2014Co-Authors: Camel Makhloufi, Elsa Lasseuguette, Jean Christophe Remigy, Bouchra Belaissaoui, Denis Roizard, Eric FavreAbstract:Due to its low regeneration energy demands relative to MEA, ammonia is one of the most attractive solvents for post-combustion CO2 capture processes. Nevertheless, additionally to a lower kinetic constant, a high ammonia slip takes place when the absorption process is performed in a packed column. In this study, the feasibility of an ammonia based CO2 capture process using hollow fiber Membrane Contactors is investigated. CO2 absorption experiments in ammonia have been performed with porous polypropylene Membranes (Oxyphan) and with two different dense skin composite hollow fibers: tailor made (Teflon AF2400) and commercial (TPX). It is shown that microporous Membranes do not offer stable performances, due to salt precipitation and pore blocking. Contrarily however, dense skin Membranes show stable and attracting performances, whatever the operating conditions: reduced ammonia slip and intensified CO2 mass transfer are obtained compared to packed column. The potentialities of dense skin Membrane Contactors, particularly based on fluorinated polymers, are discussed with regard to both increased CO2 mass transfer performances and mitigation of ammonia volatilization compared to conventional gas/liquid Contactors.
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Modeling strategies of Membrane Contactors for post-combustion carbon capture: A critical comparative study
Chemical Engineering Science, 2013Co-Authors: Elodie Chabanon, Denis Roizard, Eric FavreAbstract:Membrane Contactors are considered as a promising process for intensification purposes of gas-liquid absorption units. CO2 post-combustion capture is one of the currently intensively investigated applications and experiments are most often performed on lab scale hollow fiber modules with a monoethanolamine (MEA) aqueous solution, usually in a large excess, as chemical solvent. Different mathematical models, showing a broad range of intrinsic complexity, have been already proposed in order to simulate or predict the separation performances of Membrane Contactors for this application. Unfortunately, no systematic comparison of the different modeling approaches has been performed yet. This study addresses this issue through a series of experiments performed on the two main types of hollow fiber Membrane Contactors (microporous PTFE and dense PMP skin composite Membrane) under different sets of operating conditions. Four different types of models (constant overall mass transfer coefficient, 1D resistance in series, 1D and 2D convection-diffusion models) have been compared with the Membrane mass transfer coefficient as the only adjustable parameter. It is shown that the different models lead to comparable predictions of the experimental results, with slightly similar Membrane mass transfer coefficient values. This result addresses key questions in terms of strategy for model validation and with regard to the current trend of increasing model complexity. Interestingly, a different situation holds when MEA is significantly converted at the liquid outlet: in that case, a 1D model approach is required (variable mass transfer coefficient), and leads to results which are comparable to 2D models. Guidelines for a relevant model comparison strategy are finally proposed.
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Membrane Contactors for intensified post combustion carbon dioxide capture by gas liquid absorption processes
Journal of Membrane Science, 2012Co-Authors: Eric Favre, Hallvard F SvendsenAbstract:Abstract The use of Membrane Contactors for post-combustion CO 2 capture by absorption into a chemical solvent is currently one of the most intensively investigated topics in Membrane science. The main (if not the only) target of employing Membrane Contactors for this application is to provide a significant reduction in size of the absorption unit, as compared to the classical gas–liquid absorption technology, based on packed columns. Surprisingly, this key performance characteristic, which is best expressed through a so-called intensification factor, remains essentially unreported in studies dedicated to CO 2 absorption in Membrane Contactors. In this article, we recall the state of the art in terms of operating conditions and process performance for packed columns applied to CO 2 capture. Based on this, a series of challenges for Membrane material design and critical process engineering issues are discussed in order to set up a methodology for a better comparison between Membrane Contactors and packed columns. More specifically, an average volumetric CO 2 absorption capacity around 1 mol CO 2 m −3 s −1 is proposed as a baseline performance of packed columns in order to estimate the intensification factor of Membrane Contactors.
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Membrane Contactors for Postcombustion Carbon Dioxide Capture: A Comparative Study of Wetting Resistance on Long Time Scales
Industrial and engineering chemistry research, 2011Co-Authors: Elodie Chabanon, Denis Roizard, Eric FavreAbstract:The major complication of Membrane Contactors for gas absorption processes is the gradual wetting of the Membrane which increases the mass transfer resistance and annihilates process intensification performances. Two standard Membrane materials (microporous PP and PTFE) are compared to two novel composite hollow fiber materials: a dense skin layer on the liquid side prevents wetting (a PMP and a Teflon-AF dense skin coated on a PP fiber). The Contactors were tested over 1000 h for CO(2) absorption in a 30% MEA solution. The stability of the CO(2) capture efficiency over time and the overall mass transfer performances are presented and discussed. A noticeable wetting protection effect of the dense skin Membranes is obtained. A large decrease of the capture efficiency is observed with PP, and a slight decrease only is obtained with PTFE. The potentialities of the different fibers for process intensification purposes on long time use is discussed.
Saeed Shirazian - One of the best experts on this subject based on the ideXlab platform.
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theoretical investigations on the effect of absorbent type on carbon dioxide capture in hollow fiber Membrane Contactors
PLOS ONE, 2020Co-Authors: Saeed Shirazian, Ali Taghvaie Nakhjiri, Amir Heydarinasab, Mahdi GhadiriAbstract:Chemical absorption of carbon dioxide from flue or natural gas in hollow-fiber Membrane Contactors (HFMCs) has been one of the most beneficial techniques to alleviate its emission into the environment. A theoretical research study was done to investigate the change in Membrane specifications and operating conditions on CO2 absorption using different alkanolamine solvents. The mathematical model was developed for a parallel counter-current fluid flow through a HFMC. The developed model's equations were solved based on finite element method. The simulations revealed that the increase in Membrane porosity, length and the number of fibers has a positive impact on CO2 removal, while the gas flow rate and tortuosity enhancement resulted in the reduction of CO2 absorption. Furthermore, it was found that 4-diethylamino-2-butanol (DEAB) with approximately 100% CO2 absorption is suggested as the best solvent in this system, but ethyl-ethanolamine (EEA) with only 46% CO2 absorption had the lowest capacity for CO2 absorption (DEAB>MEA>EDA>MDEA>TEA>EEA). It is worth pointing out that the CO2 absorption can be improved using EEA solvent via change in Membrane specifications such as increase in Membrane porosity, length and the number of fibres.
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mathematical modeling and simulation of co2 stripping from monoethanolamine solution using nano porous Membrane Contactors
International Journal of Greenhouse Gas Control, 2013Co-Authors: Mehdi Ghadiri, Azam Marjani, Saeed ShirazianAbstract:Abstract A novel model based on the finite element analysis by COMSOL software is built to simulate the flow and concentration in a Membrane contactor for stripping of CO 2 at high operating temperature. A CFD model was developed by solving the 2D Navier–Stokes equations as well as mass conservation equations for steady-state conditions in polymeric Membrane Contactors. The model prognosticates the velocity fields and the concentration of CO 2 along the Membrane under laminar flow regime. The Membrane contactor was divided into three compartments, i.e. tube, shell and microporous Membrane. The model findings for the stripping of CO 2 using the Membrane contactor were compared with the experimental data in order to validate the proposed mass transfer model and showed great agreement. Moreover, the simulation results showed that mass transfer resistance of gas phase has a minor effect on the CO 2 stripping flux. Increasing temperature and liquid phase velocity cause enhancement of CO 2 stripping flux.
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modeling and cfd simulation of water desalination using nanoporous Membrane Contactors
Industrial & Engineering Chemistry Research, 2013Co-Authors: Mehdi Ghadiri, Safoora Fakhri, Saeed ShirazianAbstract:A two-dimensional comprehensive model was developed to predict the transport of water in the nanoporous Membrane Contactors. The considered Membrane distillation device was a counter-current flat-sheet Membrane contactor for production of pure water from saline water. The developed model formulates the fundamental transport equations of heat, mass, and momentum in the Membrane contactor. The computational fluid dynamics techniques were applied for numerical simulation of model equations. The simulation results were compared with experimental data obtained from literature and showed great agreement with the measured values. A combination of the Knudsen flow and Poiseuille flow was used in the model for estimation of diffusion inside the Membrane pores and increased the accuracy of the model. Simulation results revealed that, in the regions adjacent to the Membrane wall, the temperature difference is significant. This could be attributed to the fact that a temperature boundary layer is formed near the membr...
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implementation of the finite element method for simulation of mass transfer in Membrane Contactors
Chemical Engineering & Technology, 2012Co-Authors: Saeed Shirazian, Mashallah Rezakazemi, Mahboubeh Pishnamazi, Siamak Noroozi, Mostafa Jafari, A. Nouri, Azam MarjaniAbstract:Mathematical modeling and numerical simulation of gas separation by means of polymeric Membrane Contactors is presented. The finite element method is implemented for numerical simulation. COMSOL Multiphysics is used for simulation. Continuity equations are solved via computational fluid dynamics techniques based on the finite element method. A laminar velocity profile is applied for the solvent. Velocity distribution of the gas flow in the contactor is obtained by Happel's model. The predictions of percent CO2 removal obtained by the modeling were compared with the experimental values from literature for CO2 removal from CO2/N2 gas mixtures with amines. The modeling predictions were in good agreement with experimental data for different values of liquid flow rates.
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Separation of CO_2 by single and mixed aqueous amine solvents in Membrane Contactors: fluid flow and mass transfer modeling
Engineering with Computers, 2012Co-Authors: Saeed Shirazian, Azam Marjani, Mashallah RezakazemiAbstract:Removal of carbon dioxide from gas mixtures is of vital importance for the control of greenhouse gas emission. This study presents a numerical simulation using computational fluid dynamics of mass and momentum transfer in hollow-fiber Membrane Contactors. The simulation was conducted for physical and chemical absorption of CO_2. A mass transfer model was developed to study CO_2 transport through hollow-fiber Membrane Contactors. The model considers axial and radial diffusions in the contactor. It also considers convection in the tube and shell side with chemical reaction. The model equations were solved by numerical method based on finite element method. Moreover, the simulation results were validated with the experimental data obtained from literature for absorption of CO_2 in amine aqueous solutions as solvent. The simulation results were in good agreement with the experimental data for different values of gas and liquid velocities. The simulation results indicated that the removal of CO_2 increased with increasing liquid velocity in the tube side. Simulation results also showed that hollow-fiber Membrane Contactors have a great potential in the area of gas separation specially CO_2 separation from gas mixtures.
Liyuan Deng - One of the best experts on this subject based on the ideXlab platform.
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CO2 capture using highly viscous amine blends in non-porous Membrane Contactors
Chemical Engineering Journal, 2019Co-Authors: Luca Ansaloni, Hanna K Knuutila, Ardi Hartono, Muhammad Awais, Liyuan DengAbstract:Abstract New amine blends have shown a promising potential to reduce the energy penalty for CO2 capture in post combustion, making the deployment of carbon capture technologies one-step closer. However, their application at the industrial scale is threaten by their high volatility. Non-porous Membrane Contactors offer a viable solution to properly control amine emissions from these absorbents. In the present work, the CO2 capture performance of non-porous Membrane Contactors using new amine blends as liquid phase was investigated in a temperature range typical for the absorption step (25–60 °C). Different amine blends with promising features in terms of cycling capacity and regeneration energy requirement were selected as liquid absorbents. Thin composite Membranes fabricated by coating a perfluoropolymer on the top of a porous polypropylene layer were used as the interface between the gas and the liquid. At room temperature, Membrane Contactors using new absorbents exhibit a lower CO2 mass transfer coefficient compared to the benchmark (30 wt% MEA), possibly due to the high viscosity of these liquids. The modelling analysis suggests that the liquid boundary layer dominates the mass transfer resistance in the temperature range up to 40 °C, but at higher temperatures, the decrease of the solvent viscosity makes the mass transfer dominated by the Membrane phase. Interestingly, the new amine blends show better performance compared to the benchmark at higher CO2 concentrations in feed gas, highlighting a good potential to capture CO2 from concentrated flue gas from steel/cement industry or to upgrade biogas.
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development of Membrane Contactors using phase change solvents for co2 capture material compatibility study
Industrial & Engineering Chemistry Research, 2016Co-Authors: Asad Arif, Arlinda F Ciftja, Hanna K Knuutila, Liyuan DengAbstract:Phase change solvents represent a new class of CO2 absorbents with a promising potential to reduce the energy penalty associated with CO2 capture. However, their high volatility is a major concern for their use at the industrial scale. It is believed that Membrane absorption offers a solution to overcome this issue, particularly if the Membrane can prevent amine evaporation. In the present work a compatibility study is carried out in order to identify suitable Membranes in a Membrane contactor using phase change solvents as liquid absorbent. Several porous and dense polymeric samples have been studied, and their chemical stability and ability to prevent amine evaporation have been investigated through immersion tests and amine permeation experiments. The experimental results indicate that to use the blend solvents based on DEEA/MAPA (diethyl-ethanolamine/3-methylamino-propylamine) in a Membrane contactor requires a Membrane with excellent stability. Porous Membranes typically used for Membrane Contactors ...
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Precombustion CO2 Capture in Polymeric Hollow Fiber Membrane Contactors Using Ionic Liquids: Porous Membrane versus Nonporous Composite Membrane
Industrial & Engineering Chemistry Research, 2016Co-Authors: Liyuan DengAbstract:In the present work, Membrane Contactors using both porous and nonporous polymeric hollow fiber Membranes with ionic liquids as absorbent were developed for precombustion CO2 capture at elevated temperature and pressures. 1-Butyl-3-methylimidazolium tricyanomethanide [Bmim][TCM] was selected as the ILs absorbent. The compatibility and stability of six different polymeric Membranes were evaluated, while the porous PTFE Membrane and nonporous Teflon-PP composite Membrane were considered to be the most suitable Membranes for this application. Both Membrane configurations were tested and showed comparable separation performances: CO2 flux values of 4.86 × 10–4 and 4.75 × 10–4 mol m–2 s–1 were obtained for the porous PTFE and nonporous Teflon-PP Membrane contactor at 20 bar with a gas flow rate of 200 mL min–1, respectively. The Teflon-PP composite Membrane exhibited better stability as compared to the porous PTFE Membrane in a 14 day test.
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Status and progress of Membrane Contactors in post-combustion carbon capture: A state-of-the-art review of new developments
Journal of Membrane Science, 2016Co-Authors: Shuaifei Zhao, Paul Hubert Maria Feron, Jingwei Hou, Liyuan Deng, Elodie Chabanon, Eric Favre, Shuiping Yan, Vicki Chen, Hong QiAbstract:Post-combustion carbon capture (PCC), which can be retrofitted to existing units in power plants worldwide, is regarded as the first technologically feasible and effective way to combat human-induced climate change. The Membrane contactor is an emerging and promising Membrane technology for PCC as it integrates the benefits of both liquid absorption (high selectivity) and Membrane separation (modularity and compactness). This review aims to provide a state-of-the-art assessment of the research work carried out so far on Membrane contactor technology in PCC. It details common aspects of Membrane Contactors, such as technological advantages, Membrane wetting, mass transfer and module design, as well as new advances (e.g., new Membranes and absorbents used in absorption processes) and novel applications (e.g., direct CO2 stripping and integrated heat recovery in desorption processes). Moreover, the difference in performance between Membrane absorption and conventional absorption is also compared and discussed. Lastly, we discuss the status and progress of Membrane Contactors in PCC and offer some recommendations for future work. This paper provides a clear overview on the recent developments of Membrane contactor technology in PCC.
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Development of Membrane Contactors Using Phase Change Solvents for CO2 Capture: Material Compatibility Study
2016Co-Authors: Luca Ansaloni, Asad Arif, Arlinda F Ciftja, Hanna K Knuutila, Liyuan DengAbstract:Phase change solvents represent a new class of CO2 absorbents with a promising potential to reduce the energy penalty associated with CO2 capture. However, their high volatility is a major concern for their use at the industrial scale. It is believed that Membrane absorption offers a solution to overcome this issue, particularly if the Membrane can prevent amine evaporation. In the present work a compatibility study is carried out in order to identify suitable Membranes in a Membrane contactor using phase change solvents as liquid absorbent. Several porous and dense polymeric samples have been studied, and their chemical stability and ability to prevent amine evaporation have been investigated through immersion tests and amine permeation experiments. The experimental results indicate that to use the blend solvents based on DEEA/MAPA (diethyl-ethanolamine/3-methylamino-propylamine) in a Membrane contactor requires a Membrane with excellent stability. Porous Membranes typically used for Membrane Contactors with MEA aqueous solution, such as polytetrafluoroethylene (PTFE) and polypropylene (PP) Membranes, are not suitable to be used as a Membrane interface with this new class of absorbents. A selection of Membrane materials for the fabrication of thin composite Membranes suitable for this application has been identified and their CO2 and amine transport properties have been determined. Finally, the wettability of the most suitable polymer for the dense layer has been measured for different absorbent concentrations in order to ensure a good interfacial contact in the Membrane contactor
Amir Mansourizadeh - One of the best experts on this subject based on the ideXlab platform.
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blend polyvinylidene fluoride surface modifying macromolecule hollow fiber Membrane Contactors for co2 absorption
International Journal of Greenhouse Gas Control, 2014Co-Authors: Amir Mansourizadeh, Z. Aslmahdavi, Ahmad Fauzi IsmailAbstract:Abstract Recently, Membrane Contactors have attracted attentions as an efficient and flexible technology for CO 2 capture. In the present work, blend hydrophobic polyvinylidene fluoride (PVDF) hollow fiber Membranes were prepared via a dry–wet phase-inversion process. Surface modifying macromolecule (SMM) was introduced to improve the Membrane properties for CO 2 absorption in gas–liquid Membrane Contactors. The effect of SMM concentration in the polymer dope, air gap distance and bore fluid composition on the structure and performance of the Membranes were investigated. By increasing SMM in the polymer dope, the Membranes presented smaller mean pore sizes, higher permeability and surface hydrophobicity. Using 2 wt.% SMM, the Membranes prepared at 24 cm air gap showed larger mean pore size, higher hydrophobicity and lower permeability compared to those prepared at 0 cm air gap. By using 60 wt.% DMAc aqueous solution as the bore fluid, the Membrane permeability and CO 2 flux significantly improved. Maximum CO 2 absorption flux of 6.8 × 10 −4 mol/m 2 s was achieved at absorbent velocity of 0.025 m/s. The surface modified Membrane demonstrated about 10% gradual CO 2 flux reduction for over 140 h of the long-term operation. In conclusion, by improving surface hydrophobicity of the Membrane, a long-term stable operation can be achieved for practical implication of gas–liquid Membrane contactor technology.
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preparation of microporous pvdf hollow fiber Membrane Contactors for co2 stripping from diethanolamine solution
Journal of Membrane Science, 2012Co-Authors: A F Ismail, R. Naim, Amir MansourizadehAbstract:Abstract Microporous polyvinylidene fluoride (PVDF) hollow fiber Membranes were fabricated via a wet-spinning process. The prepared fibers were characterized in terms of contact angle, gas permeability, wetting pressure and morphology. CO2 stripping from preloaded aqueous diethanolamine solution was conducted through the gas–liquid Membrane Contactors. The effects of lithium chloride (LiCl) concentration on the Membrane properties and CO2 stripping performance were investigated. The addition of different LiCl concentration resulted in a less finger-like structure, with highly effective surface porosity and high wetting pressure. Conversely, N2 permeability, contact angle value and Membrane pore size were reduced as the concentration of the additives were increased. For stripping flux performance, Membrane with 5 wt% LiCl demonstrated the highest flux of 1.61 × 10−2 mol/m2 s at 110 ml/min of the liquid flow rate. It was found that the Membrane with less finger-like structure and higher effective surface porosity exhibited higher stripping efficiency. These results suggest that developed Membrane structure can be an alternative for the CO2 stripping through gas–liquid Membrane Contactors.
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hollow fiber gas liquid Membrane Contactors for acid gas capture a review
Journal of Hazardous Materials, 2009Co-Authors: Amir Mansourizadeh, Ahmad Fauzi IsmailAbstract:Membrane Contactors using microporous Membranes for acid gas removal have been extensively reviewed and discussed. The microporous Membrane acts as a fixed interface between the gas and the liquid phase without dispersing one phase into another that offers a flexible modular and energy efficient device. The gas absorption process can offer a high selectivity and a high driving force for transport even at low concentrations. Using hollow fiber gas-liquid Membrane Contactors is a promising alternative to conventional gas absorption systems for acid gas capture from gas streams. Important aspects of Membrane contactor as an efficient energy devise for acid gas removal including liquid absorbents, Membrane characteristics, combination of Membrane and absorbent, mass transfer, Membrane modules, model development, advantages and disadvantages were critically discussed. In addition, current status and future potential in research and development of gas-liquid Membrane Contactors for acid gas removal were also briefly discussed.
Denis Roizard - One of the best experts on this subject based on the ideXlab platform.
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Ammonia based CO2 capture process using hollow fiber Membrane Contactors
Journal of Membrane Science, 2014Co-Authors: Camel Makhloufi, Elsa Lasseuguette, Jean Christophe Remigy, Bouchra Belaissaoui, Denis Roizard, Eric FavreAbstract:Due to its low regeneration energy demands relative to MEA, ammonia is one of the most attractive solvents for post-combustion CO2 capture processes. Nevertheless, additionally to a lower kinetic constant, a high ammonia slip takes place when the absorption process is performed in a packed column. In this study, the feasibility of an ammonia based CO2 capture process using hollow fiber Membrane Contactors is investigated. CO2 absorption experiments in ammonia have been performed with porous polypropylene Membranes (Oxyphan) and with two different dense skin composite hollow fibers: tailor made (Teflon AF2400) and commercial (TPX). It is shown that microporous Membranes do not offer stable performances, due to salt precipitation and pore blocking. Contrarily however, dense skin Membranes show stable and attracting performances, whatever the operating conditions: reduced ammonia slip and intensified CO2 mass transfer are obtained compared to packed column. The potentialities of dense skin Membrane Contactors, particularly based on fluorinated polymers, are discussed with regard to both increased CO2 mass transfer performances and mitigation of ammonia volatilization compared to conventional gas/liquid Contactors.
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Modeling strategies of Membrane Contactors for post-combustion carbon capture: A critical comparative study
Chemical Engineering Science, 2013Co-Authors: Elodie Chabanon, Denis Roizard, Eric FavreAbstract:Membrane Contactors are considered as a promising process for intensification purposes of gas-liquid absorption units. CO2 post-combustion capture is one of the currently intensively investigated applications and experiments are most often performed on lab scale hollow fiber modules with a monoethanolamine (MEA) aqueous solution, usually in a large excess, as chemical solvent. Different mathematical models, showing a broad range of intrinsic complexity, have been already proposed in order to simulate or predict the separation performances of Membrane Contactors for this application. Unfortunately, no systematic comparison of the different modeling approaches has been performed yet. This study addresses this issue through a series of experiments performed on the two main types of hollow fiber Membrane Contactors (microporous PTFE and dense PMP skin composite Membrane) under different sets of operating conditions. Four different types of models (constant overall mass transfer coefficient, 1D resistance in series, 1D and 2D convection-diffusion models) have been compared with the Membrane mass transfer coefficient as the only adjustable parameter. It is shown that the different models lead to comparable predictions of the experimental results, with slightly similar Membrane mass transfer coefficient values. This result addresses key questions in terms of strategy for model validation and with regard to the current trend of increasing model complexity. Interestingly, a different situation holds when MEA is significantly converted at the liquid outlet: in that case, a 1D model approach is required (variable mass transfer coefficient), and leads to results which are comparable to 2D models. Guidelines for a relevant model comparison strategy are finally proposed.
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Membrane Contactors for Postcombustion Carbon Dioxide Capture: A Comparative Study of Wetting Resistance on Long Time Scales
Industrial and engineering chemistry research, 2011Co-Authors: Elodie Chabanon, Denis Roizard, Eric FavreAbstract:The major complication of Membrane Contactors for gas absorption processes is the gradual wetting of the Membrane which increases the mass transfer resistance and annihilates process intensification performances. Two standard Membrane materials (microporous PP and PTFE) are compared to two novel composite hollow fiber materials: a dense skin layer on the liquid side prevents wetting (a PMP and a Teflon-AF dense skin coated on a PP fiber). The Contactors were tested over 1000 h for CO(2) absorption in a 30% MEA solution. The stability of the CO(2) capture efficiency over time and the overall mass transfer performances are presented and discussed. A noticeable wetting protection effect of the dense skin Membranes is obtained. A large decrease of the capture efficiency is observed with PP, and a slight decrease only is obtained with PTFE. The potentialities of the different fibers for process intensification purposes on long time use is discussed.
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Membrane Contactors for intensified post combustion carbon dioxide capture by gas liquid absorption in mea a parametric study
Chemical Engineering Research & Design, 2011Co-Authors: Roda Bounaceur, Denis Roizard, Christophe Castel, Sabine Rode, Eric FavreAbstract:Post combustion carbon dioxide capture raises tremendous chemical engineering challenges. For the first generation of industrial installations, gas liquid absorption in chemical solvents is classically considered to be the best available technology. Two major bottlenecks have however to be solved in order to achieve technico-economical targets: decrease the energy requirement of the process (e.g. through novel solvents or heat integration approaches) and decrease the size of the installation (through process intensification). This study intends to explore the possibilities and limitations of Membrane Contactors, which are considered as one of the most promising strategy for intensified CO2 capture by gas–liquid absorption. A very large number of studies is continuously reported on this topic, including materials, mass transfer or process design issues, but a rigorous evaluation of their effective potential in terms of intensification is still lacking. Moreover, controversial results have been reported such as intensification factors, compared to packed columns, ranging between 10 and 0.8 on a total unit volume basis. This unclear situation results from different factors. First, experimental comparison of Membrane Contactors vs. packed absorption columns performances is indeed seldom. Second, the evaluation of Membrane Contactors is systematically performed at laboratory scale, under operating conditions which do not necessarily reflect industrial operation (i.e. fresh amine solutions are used, limited capture ratio are achieved). These simplifying assumptions have obviously to be reconsidered if a realistic comparison for industrial operation is aimed. More importantly, pressure drop levels, which are known to be very small for packed columns (typically 50 mBar on the gas side for an industrial packed column), have to be considered in order to minimize the energy impact of the process. An analysis combining intensification and pressure drop aspects for Membrane Contactors design, with solvent flowing inside the fibers, and the associated trade-off, which, to our knowledge, has not been achieved for CO2 absorption, is presented based on experimental and simulation results. Practical guidelines on the set of conditions for Membrane materials (i.e. permeability and thickness), fiber geometry (external diameter, thickness) and module design (length, packing factor) which enable a significant process intensification effect are finally proposed.