Angewandte Chemie (International ed. in English), Oct 4, 2016
New rigid polyimides with bulky CF3 groups were synthesized and engineered into high-performance ... more New rigid polyimides with bulky CF3 groups were synthesized and engineered into high-performance hollow fiber membranes. The enhanced rotational barrier provided by properly positioned CF3 side groups prohibited fiber transition layer collapse during cross-linking, thereby greatly improving CO2 /CH4 separation performance compared to conventional materials for aggressive natural gas feeds.
We describe a new template-free method for the in situ formation of a monodispersed spherical mes... more We describe a new template-free method for the in situ formation of a monodispersed spherical mesoporous nanosilica-Torlon hollow-fiber composite. A thin layer of Torlon hollow fiber that comprises silica nanoparticles was created by the in situ extrusion of a tetraethyl orthosilicate/N-methyl-2-pyrrolidone solution in a sheath layer and a Torlon polymer dope in a core support layer. This new method can be integrated easily into current hollow-fiber composite fabrication processes. The hollow-fiber composites were then functionalized with 3-aminopropyltrimethoxy silane (APS) and evaluated for their CO2 -capture performance. The resulting APS-functionalized mesoporous silica nanoparticles/Torlon hollow fibers exhibited a high CO2 equilibrium capacity of 1.5 and 1.9 mmol g(-1) at 35 and 60 °C, respectively, which is significantly higher than values for fiber sorbents without nanoparticles reported previously.
Post-spinning infusion of poly(ethyleneimine) into polymer/silica hollow fiber sorbents for CO2/N... more Post-spinning infusion of poly(ethyleneimine) into polymer/silica hollow fiber sorbents for CO2/N2 gas separation Ying Labreche1, Ryan P. Lively2, Fateme Rezaei1, Grace Chen1, David S. Sholl1, Christopher W. Jones1,*, William J. Koros1,* 1 Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, GA 30332-0100, USA 2 Algenol Biofuels, 28100 Bonita Grande Drive, Bonita Springs, Florida 34315, United States Abstract Amine-loaded hollow fiber sorbents for post-combustion CO2recovery were created by utilizing a novel post-spinning infusion technique. This technique infused poly(ethyleneimine) (PEI) into cellulose acetate/mesoporous silica hollow fiber sorbents during the solvent exchange after spinning. A suitable post-spinning infusing solution was found to be 10% PEI in methanol with an infusion time of 4 h. After amine infusion, the 51 wt% silica hollow fiber sorbents were found to have a nitrogen loading of 0.52 mmol/g-fiber and a CO2 uptake of 1.2 mmol/g-fiber at equilibrium. T...
Post-combustion CO2 capture using PAI polymer/silica/PEI hollow fiber sorbents Ying Labreche1, Ya... more Post-combustion CO2 capture using PAI polymer/silica/PEI hollow fiber sorbents Ying Labreche1, Yanfang Fang1, Fateme Rezaei1, Ryan P. Lively2, Christopher W. Jones1,*, William J. Koros1,* 1 Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, GA 30332-0100, USA 2 Algenol Biofuels, 28100 Bonita Grande Drive, Bonita Springs, Florida 34315, United States Abstract Amine-loaded cellulose acetate (CA) polymer/silica hollow fiber sorbents for post-combustion CO2 recovery were created successfully by utilizing a post-spinning amine infusion technique [1]. After initial work focusing on CA fibers [1-2], poly(amide-imide) (PAI), fibers were created, as this polymer is more thermally and mechanically stable than CA. Poly(ethyleneimine) (PEI) was infused into PAI/mesoporous silica hollow fiber sorbents during the solvent exchange steps after fiber spinning. After infusing the 50 wt% silica hollow fiber sorbents with 10% PEI solutions in methanol, the fiber sorbents were demonstrated to...
For amine-based hollow fiber sorbents to be useful in practical CO2 capture applications, it is c... more For amine-based hollow fiber sorbents to be useful in practical CO2 capture applications, it is crucial to exhibit a stable performance and a long lifetime in the presence of flue gas impurities. In our earlier investigation,1 we studied the stability of supported amine sorbents to SOx and NOx gas impurities. Here, as a next step, the stability of amine-containing polymer/silica hollow fiber sorbents to SO2, NO and NO2 impurities during CO2 capture is evaluated by conducting cyclic adsorption – desorption experiments in a rapid temperature swing adsorption process. Fiber sorbents containing primary, secondary, and tertiary amine moieties are exposed to different gas mixtures, comprising SO2/CO2, NO/CO2 and NO2/CO2 using different SOx and NOx concentrations. Furthermore, to assess any synergies in co-adsorption of SOx or NOx and CO2 gases, multi-component adsorption measurements are carried out using a mixture of SO2/NO/CO2, in addition to the binary-component adsorption measurements...
Abstract Greenhouse gas emissions from coal-fired power plants are expected to increase over the ... more Abstract Greenhouse gas emissions from coal-fired power plants are expected to increase over the next 20 years as international demand for energy continues to grow. A rapid temperature swing adsorption (RTSA) process employing polymeric hollow fiber contactors loaded with sorbent particles has been demonstrated experimentally as a novel and efficient process for postcombustion CO 2 capture. One of the advantages of the process is the rapid heat and mass transfer enabled by the hollow fibers. This feature can achieve efficient heat integration by recycling spent hot and cold water. In this chapter, a dynamic optimization strategy was employed to find the optimal operating conditions of a hollow fiber RTSA process. In the optimization problem, dynamic heat integration is performed to minimize the utility cost for hot and cold water while maintaining sufficient CO 2 throughput. The optimal operation was evaluated by a detailed technoeconomic analysis for a plant capacity of 550 MW.
Angewandte Chemie (International ed. in English), Jan 13, 2015
Flexible composite polymer/oxide hollow fibers are used as flow reactors for heterogeneously cata... more Flexible composite polymer/oxide hollow fibers are used as flow reactors for heterogeneously catalyzed reactions in organic synthesis. The fiber synthesis allows for a variety of supported catalysts to be embedded in the walls of the fibers, thus leading to a diverse set of reactions that can be catalyzed in flow. Additionally, the fiber synthesis is scalable (e.g. several reactor beds containing many fibers in a module may be used) and thus they could potentially be used for the large-scale production of organic compounds. Incorporating heterogeneous catalysts in the walls of the fibers presents an alternative to a traditional packed-bed reactor and avoids large pressure drops, which is a crucial challenge when employing microreactors.
ZIF‐8/6FDA‐DAM, a proven mixed‐matrix material that demonstrated remarkably enhanced C3H6/C3H8 se... more ZIF‐8/6FDA‐DAM, a proven mixed‐matrix material that demonstrated remarkably enhanced C3H6/C3H8 selectivity in dense film geometry, was extended to scalable hollow fiber geometry in the current work. We successfully formed dual‐layer ZIF‐8/6FDA‐DAM mixed‐matrix hollow fiber membranes with ZIF‐8 nanoparticle loading up to 30 wt % using the conventional dry‐jet/wet‐quench fiber spinning technique. The mixed‐matrix hollow fibers showed significantly enhanced C3H6/C3H8 selectivity that was consistent with mixed‐matrix dense films. Critical variables controlling successful formation of mixed‐matrix hollow fiber membranes with desirable morphology and attractive transport properties were discussed. Furthermore, the effects of coating materials on selectivity recovery of partially defective fibers were investigated. To our best knowledge, this is the first article reporting successful formation of high‐loading mixed‐matrix hollow fiber membranes with significantly enhanced selectivity for s...
The dynamic adsorption behavior of CO2 under both nonisothermal and nearly isothermal conditions ... more The dynamic adsorption behavior of CO2 under both nonisothermal and nearly isothermal conditions in silica supported poly(ethylenimine) (PEI) hollow fiber sorbents (Torlon®‐S‐PEI) is investigated in a rapid temperature swing adsorption (RTSA) process. A maximum CO2 breakthrough capacity of 1.33 mmol/g‐fiber (2.66 mmol/g‐silica) is observed when the fibers are actively cooled by flowing cooling water in the fiber bores. Under dry CO2 adsorption conditions, heat released from the CO2‐amine interaction increases the CO2 breakthrough capacity by reducing the severity of the diffusion resistance in the supported PEI. This internal resistance can also be alleviated by prehydrating the fiber sorbent with a humid N2 feed. The CO2 breakthrough capacity of prehydrated fibers is adversely affected by the release of the adsorption enthalpy (unlike the dry fibers); however, active cooling of the fiber results in a constant CO2 breakthrough capacity even at high CO2 delivery rates (i.e., high ads...
Industrial & Engineering Chemistry Research, 2015
ABSTRACT The dynamic CO2 sorption performance of polymer/silica supported polyethylenimine hollow... more ABSTRACT The dynamic CO2 sorption performance of polymer/silica supported polyethylenimine hollow fiber sorbents (CA-S-PEI), focusing on heat and mass transport effects, is investigated experimentally and computationally during sorption of CO2 from simulated, dry flue gases. The effect of the nonisothermality on the sorption performance is investigated by varying the module materials of construction. The heat effects are minimized by using a heat conductive module case with a diameter of 0.25 in., and, accordingly, the breakthrough capacities are increased by 30% over a similar module constructed from less conductive components, thereby improving fiber sorbents utilization efficiency. The sorption kinetics in CA-S-PEI hollow fiber sorbents are investigated in terms of flow rates, module packing fraction, module length, and silica particle size. A mathematical model developed previously is successfully utilized to predict various contributions to the overall mass transfer resistance. In fiber sorbents where the amine loading is high, such as those employed here, the sorption process is found to be controlled by intraparticle mass transfer resistances. Unlike fiber sorbents based on physisorbents, the external gas diffusion resistance has minimal effects on the breakthrough capacities, as evidenced with the negligible effects of the module packing fraction on the sorption capacities. Sorption capacities are found to increase with the fiber module length as a result of self-sharpening effects. The increase of particle size increases the mass transfer resistance of the fiber sorbents as illustrated by the more diffuse CO2 breakthrough fronts in fiber modules containing bigger silica particles. The capacities in fiber sorbents with the largest silica particles exhibit the lowest sorption capacity, as expected.
Angewandte Chemie (International ed. in English), Oct 4, 2016
New rigid polyimides with bulky CF3 groups were synthesized and engineered into high-performance ... more New rigid polyimides with bulky CF3 groups were synthesized and engineered into high-performance hollow fiber membranes. The enhanced rotational barrier provided by properly positioned CF3 side groups prohibited fiber transition layer collapse during cross-linking, thereby greatly improving CO2 /CH4 separation performance compared to conventional materials for aggressive natural gas feeds.
We describe a new template-free method for the in situ formation of a monodispersed spherical mes... more We describe a new template-free method for the in situ formation of a monodispersed spherical mesoporous nanosilica-Torlon hollow-fiber composite. A thin layer of Torlon hollow fiber that comprises silica nanoparticles was created by the in situ extrusion of a tetraethyl orthosilicate/N-methyl-2-pyrrolidone solution in a sheath layer and a Torlon polymer dope in a core support layer. This new method can be integrated easily into current hollow-fiber composite fabrication processes. The hollow-fiber composites were then functionalized with 3-aminopropyltrimethoxy silane (APS) and evaluated for their CO2 -capture performance. The resulting APS-functionalized mesoporous silica nanoparticles/Torlon hollow fibers exhibited a high CO2 equilibrium capacity of 1.5 and 1.9 mmol g(-1) at 35 and 60 °C, respectively, which is significantly higher than values for fiber sorbents without nanoparticles reported previously.
Post-spinning infusion of poly(ethyleneimine) into polymer/silica hollow fiber sorbents for CO2/N... more Post-spinning infusion of poly(ethyleneimine) into polymer/silica hollow fiber sorbents for CO2/N2 gas separation Ying Labreche1, Ryan P. Lively2, Fateme Rezaei1, Grace Chen1, David S. Sholl1, Christopher W. Jones1,*, William J. Koros1,* 1 Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, GA 30332-0100, USA 2 Algenol Biofuels, 28100 Bonita Grande Drive, Bonita Springs, Florida 34315, United States Abstract Amine-loaded hollow fiber sorbents for post-combustion CO2recovery were created by utilizing a novel post-spinning infusion technique. This technique infused poly(ethyleneimine) (PEI) into cellulose acetate/mesoporous silica hollow fiber sorbents during the solvent exchange after spinning. A suitable post-spinning infusing solution was found to be 10% PEI in methanol with an infusion time of 4 h. After amine infusion, the 51 wt% silica hollow fiber sorbents were found to have a nitrogen loading of 0.52 mmol/g-fiber and a CO2 uptake of 1.2 mmol/g-fiber at equilibrium. T...
Post-combustion CO2 capture using PAI polymer/silica/PEI hollow fiber sorbents Ying Labreche1, Ya... more Post-combustion CO2 capture using PAI polymer/silica/PEI hollow fiber sorbents Ying Labreche1, Yanfang Fang1, Fateme Rezaei1, Ryan P. Lively2, Christopher W. Jones1,*, William J. Koros1,* 1 Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, GA 30332-0100, USA 2 Algenol Biofuels, 28100 Bonita Grande Drive, Bonita Springs, Florida 34315, United States Abstract Amine-loaded cellulose acetate (CA) polymer/silica hollow fiber sorbents for post-combustion CO2 recovery were created successfully by utilizing a post-spinning amine infusion technique [1]. After initial work focusing on CA fibers [1-2], poly(amide-imide) (PAI), fibers were created, as this polymer is more thermally and mechanically stable than CA. Poly(ethyleneimine) (PEI) was infused into PAI/mesoporous silica hollow fiber sorbents during the solvent exchange steps after fiber spinning. After infusing the 50 wt% silica hollow fiber sorbents with 10% PEI solutions in methanol, the fiber sorbents were demonstrated to...
For amine-based hollow fiber sorbents to be useful in practical CO2 capture applications, it is c... more For amine-based hollow fiber sorbents to be useful in practical CO2 capture applications, it is crucial to exhibit a stable performance and a long lifetime in the presence of flue gas impurities. In our earlier investigation,1 we studied the stability of supported amine sorbents to SOx and NOx gas impurities. Here, as a next step, the stability of amine-containing polymer/silica hollow fiber sorbents to SO2, NO and NO2 impurities during CO2 capture is evaluated by conducting cyclic adsorption – desorption experiments in a rapid temperature swing adsorption process. Fiber sorbents containing primary, secondary, and tertiary amine moieties are exposed to different gas mixtures, comprising SO2/CO2, NO/CO2 and NO2/CO2 using different SOx and NOx concentrations. Furthermore, to assess any synergies in co-adsorption of SOx or NOx and CO2 gases, multi-component adsorption measurements are carried out using a mixture of SO2/NO/CO2, in addition to the binary-component adsorption measurements...
Abstract Greenhouse gas emissions from coal-fired power plants are expected to increase over the ... more Abstract Greenhouse gas emissions from coal-fired power plants are expected to increase over the next 20 years as international demand for energy continues to grow. A rapid temperature swing adsorption (RTSA) process employing polymeric hollow fiber contactors loaded with sorbent particles has been demonstrated experimentally as a novel and efficient process for postcombustion CO 2 capture. One of the advantages of the process is the rapid heat and mass transfer enabled by the hollow fibers. This feature can achieve efficient heat integration by recycling spent hot and cold water. In this chapter, a dynamic optimization strategy was employed to find the optimal operating conditions of a hollow fiber RTSA process. In the optimization problem, dynamic heat integration is performed to minimize the utility cost for hot and cold water while maintaining sufficient CO 2 throughput. The optimal operation was evaluated by a detailed technoeconomic analysis for a plant capacity of 550 MW.
Angewandte Chemie (International ed. in English), Jan 13, 2015
Flexible composite polymer/oxide hollow fibers are used as flow reactors for heterogeneously cata... more Flexible composite polymer/oxide hollow fibers are used as flow reactors for heterogeneously catalyzed reactions in organic synthesis. The fiber synthesis allows for a variety of supported catalysts to be embedded in the walls of the fibers, thus leading to a diverse set of reactions that can be catalyzed in flow. Additionally, the fiber synthesis is scalable (e.g. several reactor beds containing many fibers in a module may be used) and thus they could potentially be used for the large-scale production of organic compounds. Incorporating heterogeneous catalysts in the walls of the fibers presents an alternative to a traditional packed-bed reactor and avoids large pressure drops, which is a crucial challenge when employing microreactors.
ZIF‐8/6FDA‐DAM, a proven mixed‐matrix material that demonstrated remarkably enhanced C3H6/C3H8 se... more ZIF‐8/6FDA‐DAM, a proven mixed‐matrix material that demonstrated remarkably enhanced C3H6/C3H8 selectivity in dense film geometry, was extended to scalable hollow fiber geometry in the current work. We successfully formed dual‐layer ZIF‐8/6FDA‐DAM mixed‐matrix hollow fiber membranes with ZIF‐8 nanoparticle loading up to 30 wt % using the conventional dry‐jet/wet‐quench fiber spinning technique. The mixed‐matrix hollow fibers showed significantly enhanced C3H6/C3H8 selectivity that was consistent with mixed‐matrix dense films. Critical variables controlling successful formation of mixed‐matrix hollow fiber membranes with desirable morphology and attractive transport properties were discussed. Furthermore, the effects of coating materials on selectivity recovery of partially defective fibers were investigated. To our best knowledge, this is the first article reporting successful formation of high‐loading mixed‐matrix hollow fiber membranes with significantly enhanced selectivity for s...
The dynamic adsorption behavior of CO2 under both nonisothermal and nearly isothermal conditions ... more The dynamic adsorption behavior of CO2 under both nonisothermal and nearly isothermal conditions in silica supported poly(ethylenimine) (PEI) hollow fiber sorbents (Torlon®‐S‐PEI) is investigated in a rapid temperature swing adsorption (RTSA) process. A maximum CO2 breakthrough capacity of 1.33 mmol/g‐fiber (2.66 mmol/g‐silica) is observed when the fibers are actively cooled by flowing cooling water in the fiber bores. Under dry CO2 adsorption conditions, heat released from the CO2‐amine interaction increases the CO2 breakthrough capacity by reducing the severity of the diffusion resistance in the supported PEI. This internal resistance can also be alleviated by prehydrating the fiber sorbent with a humid N2 feed. The CO2 breakthrough capacity of prehydrated fibers is adversely affected by the release of the adsorption enthalpy (unlike the dry fibers); however, active cooling of the fiber results in a constant CO2 breakthrough capacity even at high CO2 delivery rates (i.e., high ads...
Industrial & Engineering Chemistry Research, 2015
ABSTRACT The dynamic CO2 sorption performance of polymer/silica supported polyethylenimine hollow... more ABSTRACT The dynamic CO2 sorption performance of polymer/silica supported polyethylenimine hollow fiber sorbents (CA-S-PEI), focusing on heat and mass transport effects, is investigated experimentally and computationally during sorption of CO2 from simulated, dry flue gases. The effect of the nonisothermality on the sorption performance is investigated by varying the module materials of construction. The heat effects are minimized by using a heat conductive module case with a diameter of 0.25 in., and, accordingly, the breakthrough capacities are increased by 30% over a similar module constructed from less conductive components, thereby improving fiber sorbents utilization efficiency. The sorption kinetics in CA-S-PEI hollow fiber sorbents are investigated in terms of flow rates, module packing fraction, module length, and silica particle size. A mathematical model developed previously is successfully utilized to predict various contributions to the overall mass transfer resistance. In fiber sorbents where the amine loading is high, such as those employed here, the sorption process is found to be controlled by intraparticle mass transfer resistances. Unlike fiber sorbents based on physisorbents, the external gas diffusion resistance has minimal effects on the breakthrough capacities, as evidenced with the negligible effects of the module packing fraction on the sorption capacities. Sorption capacities are found to increase with the fiber module length as a result of self-sharpening effects. The increase of particle size increases the mass transfer resistance of the fiber sorbents as illustrated by the more diffuse CO2 breakthrough fronts in fiber modules containing bigger silica particles. The capacities in fiber sorbents with the largest silica particles exhibit the lowest sorption capacity, as expected.
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