Hydrate formation rate and separation effect on the capture of CO2 from binary mixture via forming hydrate with 5 wt% tetra-n-butyl ammonium bromide （TBAB） solution were studied. The results showed that the inductio...Hydrate formation rate and separation effect on the capture of CO2 from binary mixture via forming hydrate with 5 wt% tetra-n-butyl ammonium bromide （TBAB） solution were studied. The results showed that the induction time was 5 min, and the hydrate formation process finished in 1 h at 4.5 ℃ and 4.01 MPa. The hydrate formation rate constant reached the maximum of 1.84× 10^-7 molZ/（s.J） with the feed pressure of 7.30 MPa. The CO2 recovery was about 45 % in the feed pressure range from 4.30 to 7.30 MPa. Under the feed pressure of 4.30 MPa, the maximum separation factor and CO2 concentration in hydrate phase were 7.3 and 38.2 mol%, respectively. The results demonstrated that TBAB accelerated hydrate formation and enriched CO2 in hydrate phase under the gentle condition.展开更多
Amine-silica composite materials for post-combustion COcapture have attracted considerable attention because of their high COuptake at low COconcentrations, excellent COcapture selectivity in the presence of moisture,...Amine-silica composite materials for post-combustion COcapture have attracted considerable attention because of their high COuptake at low COconcentrations, excellent COcapture selectivity in the presence of moisture, and lower energy requirements for sorbent regeneration. This review discusses the recent advances in amine-silica composites for COcapture, including adsorbent preparation and characterization, COcapture under dry and moisture conditions at different COpartial pressures, sorbent regeneration, and stability after many cyclic sorption-desorption runs.展开更多
In this study, a poly（ether block amide） （Pebax 1657） composite membrane applied for COa capture was prepared by coating Pebax 1657 solution on polyacrylonitrile （PAN） ultrafiltration membrane. Ethanol/water mix...In this study, a poly（ether block amide） （Pebax 1657） composite membrane applied for COa capture was prepared by coating Pebax 1657 solution on polyacrylonitrile （PAN） ultrafiltration membrane. Ethanol/water mixture was used as the solvent of Pebax and the effects of ethanol/water mass ratios and Pebax concentration on the permeation properties of composite membrane were studied. To enhance the com- posite membrane permeance, the gutter layer, made from reactive amino silicone crosslinking with potydimethylsiloxane （PDMS）, was de- signed. The influence of crosslinldng degree of the gutter layer on membrane performance was investigated. As a result, a Pebardamino- PDMS/PAN multilayer membrane with hexane resistance was developed, showing CO2 permeance of 350 GPU and CO2/N2 selectivity over 50. The blend of polyethylene glycol dimethyl ether （PEG-DME） with Pebax as coating material was studied to further improve the membrane performance. After being combined with PEG-DME additive, CO2 permeance of the final Pebax-PEG-DME/amino-PDMS/PAN composite membrane reached 400 GPU above with CO2/Na selectivity over 65.展开更多
Porous carbon spheres are prepared by direct carbonization of potassium salt of resorcinol-formaldehyde resin spheres, and are investigated as COadsorbents. It is found that the prepared carbon materials still maintai...Porous carbon spheres are prepared by direct carbonization of potassium salt of resorcinol-formaldehyde resin spheres, and are investigated as COadsorbents. It is found that the prepared carbon materials still maintain the typical spherical shapes after the activation, and have highly developed ultra-microporosity with uniform pore size, indicating that almost the activation takes place in the interior of the polymer spheres. The narrow-distributed ultra-micropores are attributed to the "in-situ homogeneous activation"effect produced by the mono-dispersed potassium ions as a form of -OK groups in the bulk of polymer spheres. The CS-1 sample prepared under a KOH/resins weight ratio of 1 shows a very high COcapture capacity of 4.83 mmol/g and good CO/Nselectivity of7-45. We believe that the presence of a welldeveloped ultra-microporosity is responsible for excellent COsorption performance at room temperature and ambient pressure.展开更多
A membrane contactor using ionic liquids(ILs) as solvent for pre-combustion capture CO_2 at elevated temperature(303-393 K) and pressure(20 bar) has been studied using mathematic model in the present work. A comprehen...A membrane contactor using ionic liquids(ILs) as solvent for pre-combustion capture CO_2 at elevated temperature(303-393 K) and pressure(20 bar) has been studied using mathematic model in the present work. A comprehensive two-dimensional(2 D) mass-transfer model was developed based on finite element method. The effects of liquid properties, membrane configurations, as well as operation parameters on the CO_2 removal efficiency were systematically studied. The simulation results show that CO_2 can be effectively removed in this process. In addition, it is found that the liquid phase mass transfer dominated the overall mass transfer. Membranes with high porosity and small thickness could apparently reduce the membrane resistance and thus increase the separation efficiency. On the other hand, the membrane diameter and membrane length have a relatively small influence on separation performance within the operation range.展开更多
Although not everybody wants to admit,climate change has been happening with irreversible consequences.It is getting worse and worse and becoming more and more influential to not only the environment but also to all k...Although not everybody wants to admit,climate change has been happening with irreversible consequences.It is getting worse and worse and becoming more and more influential to not only the environment but also to all kinds of beings;our earth is now seriously threatened by climate change.It is a critical issue the whole society must face and actions must展开更多
Recently, a kind of hybrid solution MEA-methanol shows a better CO_2 capture performance over aqueous MEA solution. However, the vaporization of methanol is the biggest disadvantage that hinders its application, so it...Recently, a kind of hybrid solution MEA-methanol shows a better CO_2 capture performance over aqueous MEA solution. However, the vaporization of methanol is the biggest disadvantage that hinders its application, so it is necessary to minimize the vaporization of methanol during both the absorption and regeneration processes. In this work, two kinds of hybrid solutions were studied and compared with aqueous MEA solution and MEA-methanol solution, including MEA/TEA/methanol solution and MEA/glycerol/methanol solution. The absorption property of MEA/glycerol/methanol solution is better than aqueous MEA solution within a certain period of time and the absorption property of MEA/TEA/methanol solution is too poor to be used in CO_2 capture. By increasing the concentration of TEA and decreasing the concentration of MEA, the absorption rate, CO_2 capture efficiency and absorption capacity all decreased. Upon adding glycerol, the cyclic capacity decreased and the generation temperature increased, and moreover, the density and viscosity also increased considerably. So after adding TEA and glycerol, the CO_2 capture performance of MEAmethanol solvent cannot be improved.展开更多
While Fe-based oxygen carriers(OC) are regarded to be promising for chemical looping combustion(CLC),the decrease of CO_2 selectivity during deep reduction process and the severe agglomeration of Fe_2O_3 often occur a...While Fe-based oxygen carriers(OC) are regarded to be promising for chemical looping combustion(CLC),the decrease of CO_2 selectivity during deep reduction process and the severe agglomeration of Fe_2O_3 often occur after multiple redox cycles due to the low oxygen mobility.Herein,Fe-substituted Bahexaaluminates(Ba Fe_xAl_(12)– xO_(19),denoted as BF_xA-H,x = 1 and 2) prepared by a modified two-step method exhibited not only higher amount of converted oxygen(Ot) and CH_4 conversion(77% and 81% vs.17%and 75%) than those prepared by the traditional co-precipitation method(BF_xA-C,x = 1 and 2) but also high CO_2 selectivity above 92% during the nearly whole reduction from Fe^(3+) to Fe^(2+).Furthermore,the BFxA-H exhibited the excellent recyclability during 50 cycles.The better performance was ascribed to the markedly enhanced oxygen mobility which resulted from dominant occupancy of Fe cations in Al(5) sites(Fe^5: 71% and 70% vs.49% and 41%) in mirror planes of hexaaluminate leading to larger amount of lattice oxygen coordinated with Fe^5(O–Fe^5)(0.45 and 0.85 mmol/g vs.0.31 and 0.50 mmol/g).The improvement of oxygen mobility also favored the preservation of chemical state of Fe cations in hexaaluminate structure in the re-oxidation step,resulting in the excellent recyclability of BF_xA-H.展开更多
At present monoethanolamine(MEA) remains as the standard industrial solvent for CO_2 capture processes. But due to the degradation and high energy consumption problems of MEA, new efficient solvents should be found. I...At present monoethanolamine(MEA) remains as the standard industrial solvent for CO_2 capture processes. But due to the degradation and high energy consumption problems of MEA, new efficient solvents should be found. In the present work, the absorption and regeneration performance of a hybrid solvent MEA-methanol was studied and compared to the aqueous solutions of monoethanolamine(MEA), diethanolamine(DEA) and triethanolamine(TEA) in a bubbling reactor. Also the performance of MEA-methanol solutions(including the absorption performance, regeneration performance,cyclic absorption performance, density and viscosity) was studied with different MEA concentrations. A pilot-plant CO_2 capture test bed was used to study the potential of MEA-methanol to replace aqueous MEA in industrial use. The results showed that the initial absorption rate of MEA-methanol solvent is the fastest compared with other solvents. The 30% MEA-methanol had a faster mass transfer coefficient, a higher CO_2 absorption efficiency and a lower regeneration energy consumption than aqueous MEA. And through the study of the reaction heat of CO_2 into MEA-methanol and aqueous MEA,it can be concluded that the desorption heat of rich MEA-methanol is only about 30% of rich aqueous MEA solvent in the regeneration process which showed that 30% MEA-methanol solvent is a promising candidate for CO_2 capture.展开更多
Reducing the anthropogenic COemissions from fossil resource combustion and human activities has become one of the major challenges we are facing today.Beyond those practical applications for the utilization of CO,such...Reducing the anthropogenic COemissions from fossil resource combustion and human activities has become one of the major challenges we are facing today.Beyond those practical applications for the utilization of CO,such as the synthesis of salicylic acid,methanol,urea,NaHCO-NaCOchemicals and recently developed polycarbonate synthesis,scientists are still seeking new materials and technologies for efficient capture,展开更多
The development of dual functional material for cyclic CO_(2)capture and hydrogenation is of great significance for converting diluted CO_(2)into valuable fuels,but suffers from kinetic limitation and deactivation of ...The development of dual functional material for cyclic CO_(2)capture and hydrogenation is of great significance for converting diluted CO_(2)into valuable fuels,but suffers from kinetic limitation and deactivation of adsorbent and catalyst.Herein,we engineered a series of RuNa/γ-Al_(2)O_(3)materials,varying the size of ruthenium from single atoms to clusters/nanoparticles.The coordination environment and structure sensitivity of ruthenium were quantitatively investigated at atomic scale.Our findings reveal that the reduced Ru nanoparticles,approximately 7.1 nm in diameter with a Ru-Ru coordination number of 5.9,exhibit high methane formation activity and selectivity at 340°C.The Ru-Na interfacial sites facilitate CO_(2)migration through a deoxygenation pathway,involving carbonate dissociation,carbonyl formation,and hydrogenation.In-situ experiments and theoretical calculations show that stable carbonyl intermediates on metallic Ru nanoparticles facilitate heterolytic C–O scission and C–H bonding,significantly lowering the energy barrier for activating stored CO_(2).展开更多
Graphene has enormous potential to capture CO_(2)due to its unique properties and cost-effectiveness.However,graphene-based adsorbents have drawbacks of lower CO_(2)adsorption capacity and poor selectivity.This work d...Graphene has enormous potential to capture CO_(2)due to its unique properties and cost-effectiveness.However,graphene-based adsorbents have drawbacks of lower CO_(2)adsorption capacity and poor selectivity.This work demonstrates a one-step rapid and sustainable N_(2)/H_(2)plasma treatment process to prepare graphene-based sorbent material with enhanced CO_(2)adsorption performance.Plasma treatment directly enriches amine species,increases surface area,and improves textural properties.The CO_(2)adsorption capacity increases from 1.6 to 3.3 mmol/g for capturing flue gas,and from 0.14 to 1.3 mmol/g for direct air capture (DAC).Importantly,the electrothermal property of the plasma-modified aerogels has been significantly improved,resulting in faster heating rates and significantly reducing energy consumption compared to conventional external heating for regeneration of sorbents.Modified aerogels display improved selectivity of 42 and 87 after plasma modification for 5 and 10 min,respectively.The plasma-treated aerogels display minimal loss between 17%and 19% in capacity after 40 adsorption/desorption cycles,rendering excellent stability.The N_(2)/H_(2)plasma treatment of adsorbent materials would lower energy expenses and prevent negative effects on the global economy caused by climate change.展开更多
Facilitated transport membranes for post-combustion carbon capture are one of the technologies to achieve efficient and large-scale capture.The central principle is to utilize the affinity of CO_(2) for the carrier to...Facilitated transport membranes for post-combustion carbon capture are one of the technologies to achieve efficient and large-scale capture.The central principle is to utilize the affinity of CO_(2) for the carrier to achieve efficient separation and to break the Robson upper bound.This paper reviews the progress of facilitated transport membranes research regarding polymer materials,principles,and problems faced at this stage.Firstly,we briefly introduce the transport mechanism of the facilitated transport membranes.Then the research progress of several major polymers used for facilitated transport membranes for CO_(2)/N_(2) separation was presented in the past five years.Additionally,we analyze the primary challenges of facilitated transport membranes,including the influence of water,the effect of temperature,the saturation effect of the carrier,and the process configuration.Finally,we also delve into the challenges and competitiveness of facilitated transport membranes.展开更多
Temperature-swing adsorption(TSA)is an effective technique for CO_(2) capture,but the temperature swing procedure is energy-intensive.Herein,we report a low-energy-consumption system by combining passive radiative coo...Temperature-swing adsorption(TSA)is an effective technique for CO_(2) capture,but the temperature swing procedure is energy-intensive.Herein,we report a low-energy-consumption system by combining passive radiative cooling and solar heating for the uptake of CO_(2) on commercial activated carbons(CACs).During adsorption,the adsorbents are coated with a layer of hierarchically porous poly(vinylidene fluoride-co-hexafluoropropene)[P(VdF-HFP)HP],which cools the adsorbents to a low temperature under sunlight through radiative cooling.For desorption,CACs with broad absorption of the solar spectrum are exposed to light irradiation for heating.The heating and cooling processes are completely driven by solar energy.Adsorption tests under mimicked sunlight using the CACs show that the performance of this system is comparable to that of the traditional ones.Furthermore,under real sunlight irradiation,the adsorption capacity of the CACs can be well maintained after multiple cycles.The present work may inspire the development of new temperature swing procedures with little energy consumption.展开更多
Benzylamine(BZA) has been identified as a promising candidate for CO_2 capture process; however the evaluation of BZA in the packed column was very few. Thus, in this work, the absorption and regeneration performance ...Benzylamine(BZA) has been identified as a promising candidate for CO_2 capture process; however the evaluation of BZA in the packed column was very few. Thus, in this work, the absorption and regeneration performance of unblended BZA solvent as well as a series of amine concentrations and ratios in the formulations were studied using a semibatch bubbling reactor. And due to the formation of ivory-white precipitates in solvents containing higher BZA ratios, a 4:1 molar ratio of MEA/BZA mixed solvent was used to study its performance in a pilot-scale test bed. The results showed that a higher BZA ratio in the MEA/BZA mixed solvent resulted in a faster absorption rate, a higher mass transfer and heat transfer rate and a better cyclic performance, but the mass transfer rate of BZA decreased more quickly than MEA with the increase of CO_2 loading of the solvents. In addition, at high CO_2 loading in the MEA/ BZA mixed solvent with a molar ratio of 4:1, the ivory-white precipitates were generated which could cause blockage of the packing in the absorber, the stripper and the liquid pipelines.展开更多
Carbon capture,utilization and storage(CCUS) is widely recognized as a vital strategy for mitigating the impact of human induced climate change.Among various CO_(2) adsorbents,intermediate-temperature solid adsorbents...Carbon capture,utilization and storage(CCUS) is widely recognized as a vital strategy for mitigating the impact of human induced climate change.Among various CO_(2) adsorbents,intermediate-temperature solid adsorbents have garnered significant attention due to their potential applications in hydrogen utilization,specifically in the water gas shift,steam reforming and gasification processes.These processes are crucial for achieving carbon neutrality.While laboratory-level studies have showcased the high adsorption capacity of these materials via various synthesis and modification methods,their practical application in complex industrial environments remains challenging,impeding the commercialization process.This review aims to critically summarize the recent research progress made in intermediatetemperature(200-400℃) solid CO_(2) adsorbents,particularly focusing on indicators such as cyclability,gas selectivity,and formability,which play vital roles in industrial application scenarios.Additionally,we provide an overview of laboratory-level advanced technologies specifically tailored for industrial applications.Furthermore,we highlight several industrial-ready advanced technologies that can pave the way for overcoming the challenges associated with large-scale implementation.The insights provided by this review aim to assist researchers in identifying the most relevant research directions for industrial applications.By promoting advances in the application of solid adsorbents,we strive to facilitate the ultimate goal of achieving carbon neutrality.展开更多
Chemical looping combustion has the potential to be an efficient and low-cost technology capable of contributing to the reduction of the atmospheric concentration of CO_(2) in order to reach the 1.5/2°C goal and ...Chemical looping combustion has the potential to be an efficient and low-cost technology capable of contributing to the reduction of the atmospheric concentration of CO_(2) in order to reach the 1.5/2°C goal and mitigate climate change.In this process,a metal oxide is used as oxygen carrier in a dual fluidized bed to generate clean CO_(2) via combustion of biomass.Most commonly,natural ores or synthetic materials are used as oxygen carrier whereas both must meet special requirements for the conversion of solid fuels.Synthetic oxygen carriers are characterized by higher reactivity at the expense of higher costs versus the lower-cost natural ores.To determine the viability of both possibilities,a techno-economic comparison of a synthetic material based on manganese,iron,and copper to the natural ore ilmenite was conducted.The synthetic oxygen carrier was characterized and tested in a pilot plant,where high combustion efficiencies up to 98.4%and carbon capture rates up to 98.5%were reached.The techno-economic assessment resulted in CO_(2) capture costs of 75 and 40€/tCO_(2) for the synthetic and natural ore route respectively,whereas a sensitivity analysis showed the high impact of production costs and attrition rates of the synthetic material.The synthetic oxygen carrier could break even with the natural ore in case of lower production costs and attrition rates,which could be reached by adapting the production process and recycling material.By comparison to state-of-the-art technologies,it is demonstrated that both routes are viable and the capture cost of CO_(2) could be reduced by implementing the chemical looping combustion technology.展开更多
文摘Hydrate formation rate and separation effect on the capture of CO2 from binary mixture via forming hydrate with 5 wt% tetra-n-butyl ammonium bromide （TBAB） solution were studied. The results showed that the induction time was 5 min, and the hydrate formation process finished in 1 h at 4.5 ℃ and 4.01 MPa. The hydrate formation rate constant reached the maximum of 1.84× 10^-7 molZ/（s.J） with the feed pressure of 7.30 MPa. The CO2 recovery was about 45 % in the feed pressure range from 4.30 to 7.30 MPa. Under the feed pressure of 4.30 MPa, the maximum separation factor and CO2 concentration in hydrate phase were 7.3 and 38.2 mol%, respectively. The results demonstrated that TBAB accelerated hydrate formation and enriched CO2 in hydrate phase under the gentle condition.
基金supported financially by the National Natural Science Foundation of China (No. 21607121)by the National Research Foundation of Korea (NRF) (Grant number: NRF2015R1A4A1042434)
文摘Amine-silica composite materials for post-combustion COcapture have attracted considerable attention because of their high COuptake at low COconcentrations, excellent COcapture selectivity in the presence of moisture, and lower energy requirements for sorbent regeneration. This review discusses the recent advances in amine-silica composites for COcapture, including adsorbent preparation and characterization, COcapture under dry and moisture conditions at different COpartial pressures, sorbent regeneration, and stability after many cyclic sorption-desorption runs.
文摘In this study, a poly（ether block amide） （Pebax 1657） composite membrane applied for COa capture was prepared by coating Pebax 1657 solution on polyacrylonitrile （PAN） ultrafiltration membrane. Ethanol/water mixture was used as the solvent of Pebax and the effects of ethanol/water mass ratios and Pebax concentration on the permeation properties of composite membrane were studied. To enhance the com- posite membrane permeance, the gutter layer, made from reactive amino silicone crosslinking with potydimethylsiloxane （PDMS）, was de- signed. The influence of crosslinldng degree of the gutter layer on membrane performance was investigated. As a result, a Pebardamino- PDMS/PAN multilayer membrane with hexane resistance was developed, showing CO2 permeance of 350 GPU and CO2/N2 selectivity over 50. The blend of polyethylene glycol dimethyl ether （PEG-DME） with Pebax as coating material was studied to further improve the membrane performance. After being combined with PEG-DME additive, CO2 permeance of the final Pebax-PEG-DME/amino-PDMS/PAN composite membrane reached 400 GPU above with CO2/Na selectivity over 65.
基金the financial supports by the Natural Science Foundation of China (NSFC21576158, 21476132, 21576159 and 21403130)Shandong Provincial Natural Science Foundation, China (No. 2015 ZRB01765)
文摘Porous carbon spheres are prepared by direct carbonization of potassium salt of resorcinol-formaldehyde resin spheres, and are investigated as COadsorbents. It is found that the prepared carbon materials still maintain the typical spherical shapes after the activation, and have highly developed ultra-microporosity with uniform pore size, indicating that almost the activation takes place in the interior of the polymer spheres. The narrow-distributed ultra-micropores are attributed to the "in-situ homogeneous activation"effect produced by the mono-dispersed potassium ions as a form of -OK groups in the bulk of polymer spheres. The CS-1 sample prepared under a KOH/resins weight ratio of 1 shows a very high COcapture capacity of 4.83 mmol/g and good CO/Nselectivity of7-45. We believe that the presence of a welldeveloped ultra-microporosity is responsible for excellent COsorption performance at room temperature and ambient pressure.
基金partly supported by the Research Council of Norway through CLIMIT program (MCIL-CO_2 project, 215732)
文摘A membrane contactor using ionic liquids(ILs) as solvent for pre-combustion capture CO_2 at elevated temperature(303-393 K) and pressure(20 bar) has been studied using mathematic model in the present work. A comprehensive two-dimensional(2 D) mass-transfer model was developed based on finite element method. The effects of liquid properties, membrane configurations, as well as operation parameters on the CO_2 removal efficiency were systematically studied. The simulation results show that CO_2 can be effectively removed in this process. In addition, it is found that the liquid phase mass transfer dominated the overall mass transfer. Membranes with high porosity and small thickness could apparently reduce the membrane resistance and thus increase the separation efficiency. On the other hand, the membrane diameter and membrane length have a relatively small influence on separation performance within the operation range.
文摘Although not everybody wants to admit,climate change has been happening with irreversible consequences.It is getting worse and worse and becoming more and more influential to not only the environment but also to all kinds of beings;our earth is now seriously threatened by climate change.It is a critical issue the whole society must face and actions must
基金supported by the Sinopec Ningbo Engineering Co., Ltd. (No. 14850000-14-ZC0609-0003, H8XY-0032)
文摘Recently, a kind of hybrid solution MEA-methanol shows a better CO_2 capture performance over aqueous MEA solution. However, the vaporization of methanol is the biggest disadvantage that hinders its application, so it is necessary to minimize the vaporization of methanol during both the absorption and regeneration processes. In this work, two kinds of hybrid solutions were studied and compared with aqueous MEA solution and MEA-methanol solution, including MEA/TEA/methanol solution and MEA/glycerol/methanol solution. The absorption property of MEA/glycerol/methanol solution is better than aqueous MEA solution within a certain period of time and the absorption property of MEA/TEA/methanol solution is too poor to be used in CO_2 capture. By increasing the concentration of TEA and decreasing the concentration of MEA, the absorption rate, CO_2 capture efficiency and absorption capacity all decreased. Upon adding glycerol, the cyclic capacity decreased and the generation temperature increased, and moreover, the density and viscosity also increased considerably. So after adding TEA and glycerol, the CO_2 capture performance of MEAmethanol solvent cannot be improved.
基金supported by the National Science Foundation of China (NSFC) (21303137,21406225 and 21676269)the National Key Project for Fundamental Research and Development of China (2016YFA0202801)Postdoctoral Science Foundation of China (2014M561261)
文摘While Fe-based oxygen carriers(OC) are regarded to be promising for chemical looping combustion(CLC),the decrease of CO_2 selectivity during deep reduction process and the severe agglomeration of Fe_2O_3 often occur after multiple redox cycles due to the low oxygen mobility.Herein,Fe-substituted Bahexaaluminates(Ba Fe_xAl_(12)– xO_(19),denoted as BF_xA-H,x = 1 and 2) prepared by a modified two-step method exhibited not only higher amount of converted oxygen(Ot) and CH_4 conversion(77% and 81% vs.17%and 75%) than those prepared by the traditional co-precipitation method(BF_xA-C,x = 1 and 2) but also high CO_2 selectivity above 92% during the nearly whole reduction from Fe^(3+) to Fe^(2+).Furthermore,the BFxA-H exhibited the excellent recyclability during 50 cycles.The better performance was ascribed to the markedly enhanced oxygen mobility which resulted from dominant occupancy of Fe cations in Al(5) sites(Fe^5: 71% and 70% vs.49% and 41%) in mirror planes of hexaaluminate leading to larger amount of lattice oxygen coordinated with Fe^5(O–Fe^5)(0.45 and 0.85 mmol/g vs.0.31 and 0.50 mmol/g).The improvement of oxygen mobility also favored the preservation of chemical state of Fe cations in hexaaluminate structure in the re-oxidation step,resulting in the excellent recyclability of BF_xA-H.
基金supported by the Sinopec Ningbo Engineering Co., Ltd.(No.l4850000-14-ZC0609-0003, H8XY-0032)
文摘At present monoethanolamine(MEA) remains as the standard industrial solvent for CO_2 capture processes. But due to the degradation and high energy consumption problems of MEA, new efficient solvents should be found. In the present work, the absorption and regeneration performance of a hybrid solvent MEA-methanol was studied and compared to the aqueous solutions of monoethanolamine(MEA), diethanolamine(DEA) and triethanolamine(TEA) in a bubbling reactor. Also the performance of MEA-methanol solutions(including the absorption performance, regeneration performance,cyclic absorption performance, density and viscosity) was studied with different MEA concentrations. A pilot-plant CO_2 capture test bed was used to study the potential of MEA-methanol to replace aqueous MEA in industrial use. The results showed that the initial absorption rate of MEA-methanol solvent is the fastest compared with other solvents. The 30% MEA-methanol had a faster mass transfer coefficient, a higher CO_2 absorption efficiency and a lower regeneration energy consumption than aqueous MEA. And through the study of the reaction heat of CO_2 into MEA-methanol and aqueous MEA,it can be concluded that the desorption heat of rich MEA-methanol is only about 30% of rich aqueous MEA solvent in the regeneration process which showed that 30% MEA-methanol solvent is a promising candidate for CO_2 capture.
文摘Reducing the anthropogenic COemissions from fossil resource combustion and human activities has become one of the major challenges we are facing today.Beyond those practical applications for the utilization of CO,such as the synthesis of salicylic acid,methanol,urea,NaHCO-NaCOchemicals and recently developed polycarbonate synthesis,scientists are still seeking new materials and technologies for efficient capture,
基金National Key R&D Program of China(2022YFE0105900)National Natural Science Foundation of China(52306179)+1 种基金Science and Technology Innovation Program of Hunan Province(2021RC4006)High Performance Computing Center of Central South University。
文摘The development of dual functional material for cyclic CO_(2)capture and hydrogenation is of great significance for converting diluted CO_(2)into valuable fuels,but suffers from kinetic limitation and deactivation of adsorbent and catalyst.Herein,we engineered a series of RuNa/γ-Al_(2)O_(3)materials,varying the size of ruthenium from single atoms to clusters/nanoparticles.The coordination environment and structure sensitivity of ruthenium were quantitatively investigated at atomic scale.Our findings reveal that the reduced Ru nanoparticles,approximately 7.1 nm in diameter with a Ru-Ru coordination number of 5.9,exhibit high methane formation activity and selectivity at 340°C.The Ru-Na interfacial sites facilitate CO_(2)migration through a deoxygenation pathway,involving carbonate dissociation,carbonyl formation,and hydrogenation.In-situ experiments and theoretical calculations show that stable carbonyl intermediates on metallic Ru nanoparticles facilitate heterolytic C–O scission and C–H bonding,significantly lowering the energy barrier for activating stored CO_(2).
基金Guangzhou (China) government postdoctoral program for providing financial support to conduct this worksupport from the National Natural Science Foundation of China (No. 72140008)funding from the European Union’s Horizon 2020 Research and Innovation program under grant agreement No. 101022484。
文摘Graphene has enormous potential to capture CO_(2)due to its unique properties and cost-effectiveness.However,graphene-based adsorbents have drawbacks of lower CO_(2)adsorption capacity and poor selectivity.This work demonstrates a one-step rapid and sustainable N_(2)/H_(2)plasma treatment process to prepare graphene-based sorbent material with enhanced CO_(2)adsorption performance.Plasma treatment directly enriches amine species,increases surface area,and improves textural properties.The CO_(2)adsorption capacity increases from 1.6 to 3.3 mmol/g for capturing flue gas,and from 0.14 to 1.3 mmol/g for direct air capture (DAC).Importantly,the electrothermal property of the plasma-modified aerogels has been significantly improved,resulting in faster heating rates and significantly reducing energy consumption compared to conventional external heating for regeneration of sorbents.Modified aerogels display improved selectivity of 42 and 87 after plasma modification for 5 and 10 min,respectively.The plasma-treated aerogels display minimal loss between 17%and 19% in capacity after 40 adsorption/desorption cycles,rendering excellent stability.The N_(2)/H_(2)plasma treatment of adsorbent materials would lower energy expenses and prevent negative effects on the global economy caused by climate change.
文摘Facilitated transport membranes for post-combustion carbon capture are one of the technologies to achieve efficient and large-scale capture.The central principle is to utilize the affinity of CO_(2) for the carrier to achieve efficient separation and to break the Robson upper bound.This paper reviews the progress of facilitated transport membranes research regarding polymer materials,principles,and problems faced at this stage.Firstly,we briefly introduce the transport mechanism of the facilitated transport membranes.Then the research progress of several major polymers used for facilitated transport membranes for CO_(2)/N_(2) separation was presented in the past five years.Additionally,we analyze the primary challenges of facilitated transport membranes,including the influence of water,the effect of temperature,the saturation effect of the carrier,and the process configuration.Finally,we also delve into the challenges and competitiveness of facilitated transport membranes.
基金supported by the National Science Fund for Distinguished Young Scholars(22125804)the National Natural Science Foundation of China(21808110,22078155,and 21878149).
文摘Temperature-swing adsorption(TSA)is an effective technique for CO_(2) capture,but the temperature swing procedure is energy-intensive.Herein,we report a low-energy-consumption system by combining passive radiative cooling and solar heating for the uptake of CO_(2) on commercial activated carbons(CACs).During adsorption,the adsorbents are coated with a layer of hierarchically porous poly(vinylidene fluoride-co-hexafluoropropene)[P(VdF-HFP)HP],which cools the adsorbents to a low temperature under sunlight through radiative cooling.For desorption,CACs with broad absorption of the solar spectrum are exposed to light irradiation for heating.The heating and cooling processes are completely driven by solar energy.Adsorption tests under mimicked sunlight using the CACs show that the performance of this system is comparable to that of the traditional ones.Furthermore,under real sunlight irradiation,the adsorption capacity of the CACs can be well maintained after multiple cycles.The present work may inspire the development of new temperature swing procedures with little energy consumption.
基金supported by the Sinopec Ningbo Engineering Co. Ltd. (No.l4850000-14-ZC0609-0003,H8XY-0032)
文摘Benzylamine(BZA) has been identified as a promising candidate for CO_2 capture process; however the evaluation of BZA in the packed column was very few. Thus, in this work, the absorption and regeneration performance of unblended BZA solvent as well as a series of amine concentrations and ratios in the formulations were studied using a semibatch bubbling reactor. And due to the formation of ivory-white precipitates in solvents containing higher BZA ratios, a 4:1 molar ratio of MEA/BZA mixed solvent was used to study its performance in a pilot-scale test bed. The results showed that a higher BZA ratio in the MEA/BZA mixed solvent resulted in a faster absorption rate, a higher mass transfer and heat transfer rate and a better cyclic performance, but the mass transfer rate of BZA decreased more quickly than MEA with the increase of CO_2 loading of the solvents. In addition, at high CO_2 loading in the MEA/ BZA mixed solvent with a molar ratio of 4:1, the ivory-white precipitates were generated which could cause blockage of the packing in the absorber, the stripper and the liquid pipelines.
基金funded by the National Key R&D Program of China(2022YFB4101702)the National Natural Science Foundation of China(52106072 and 52225003)the Fundamental Research Funds for Central Universities(2019JQ03015)。
文摘Carbon capture,utilization and storage(CCUS) is widely recognized as a vital strategy for mitigating the impact of human induced climate change.Among various CO_(2) adsorbents,intermediate-temperature solid adsorbents have garnered significant attention due to their potential applications in hydrogen utilization,specifically in the water gas shift,steam reforming and gasification processes.These processes are crucial for achieving carbon neutrality.While laboratory-level studies have showcased the high adsorption capacity of these materials via various synthesis and modification methods,their practical application in complex industrial environments remains challenging,impeding the commercialization process.This review aims to critically summarize the recent research progress made in intermediatetemperature(200-400℃) solid CO_(2) adsorbents,particularly focusing on indicators such as cyclability,gas selectivity,and formability,which play vital roles in industrial application scenarios.Additionally,we provide an overview of laboratory-level advanced technologies specifically tailored for industrial applications.Furthermore,we highlight several industrial-ready advanced technologies that can pave the way for overcoming the challenges associated with large-scale implementation.The insights provided by this review aim to assist researchers in identifying the most relevant research directions for industrial applications.By promoting advances in the application of solid adsorbents,we strive to facilitate the ultimate goal of achieving carbon neutrality.
文摘Chemical looping combustion has the potential to be an efficient and low-cost technology capable of contributing to the reduction of the atmospheric concentration of CO_(2) in order to reach the 1.5/2°C goal and mitigate climate change.In this process,a metal oxide is used as oxygen carrier in a dual fluidized bed to generate clean CO_(2) via combustion of biomass.Most commonly,natural ores or synthetic materials are used as oxygen carrier whereas both must meet special requirements for the conversion of solid fuels.Synthetic oxygen carriers are characterized by higher reactivity at the expense of higher costs versus the lower-cost natural ores.To determine the viability of both possibilities,a techno-economic comparison of a synthetic material based on manganese,iron,and copper to the natural ore ilmenite was conducted.The synthetic oxygen carrier was characterized and tested in a pilot plant,where high combustion efficiencies up to 98.4%and carbon capture rates up to 98.5%were reached.The techno-economic assessment resulted in CO_(2) capture costs of 75 and 40€/tCO_(2) for the synthetic and natural ore route respectively,whereas a sensitivity analysis showed the high impact of production costs and attrition rates of the synthetic material.The synthetic oxygen carrier could break even with the natural ore in case of lower production costs and attrition rates,which could be reached by adapting the production process and recycling material.By comparison to state-of-the-art technologies,it is demonstrated that both routes are viable and the capture cost of CO_(2) could be reduced by implementing the chemical looping combustion technology.
