Direct air capture(DAC)of CO_(2)plays an indispensable role in achieving carbon-neutral goals as one of the key negative emission technologies.Since large air flows are required to capture the ultradilute CO_(2)from t...Direct air capture(DAC)of CO_(2)plays an indispensable role in achieving carbon-neutral goals as one of the key negative emission technologies.Since large air flows are required to capture the ultradilute CO_(2)from the air,lab-synthesized adsorbents in powder form may cause unacceptable gas pressure drops and poor heat and mass transfer efficiencies.A structured adsorbent is essential for the implementation of gas-solid contactors for cost-and energy-efficient DAC systems.In this study,efficient adsorbent poly(ethyleneimine)(PEI)-functionalized Mg-Al-CO_(3)layered double hydroxide(LDH)-derived mixed metal oxides(MMOs)are three-dimensional(3D)printed into monoliths for the first time with more than 90%adsorbent loadings.The printing process has been optimized by initially printing the LDH powder into monoliths followed by calcination into MMO monoliths.This structure exhibits a 32.7%higher specific surface area and a 46.1%higher pore volume,as compared to the direct printing of the MMO powder into a monolith.After impregnation of PEI,the monolith demonstrates a large adsorption capacity(1.82 mmol/g)and fast kinetics(0.7 mmol/g/h)using a CO_(2)feed gas at 400 ppm at 25℃,one of the highest values among the shaped DAC adsorbents.Smearing of the amino-polymers during the post-printing process affects the diffusion of CO_(2),resulting in slower adsorption kinetics of pre-impregnation monoliths compared to post-impregnation monoliths.The optimal PEI/MeOH ratio for the post-impregnation solution prevents pores clogging that would affect both adsorption capacity and kinetics.展开更多
Global warming and associated global climate change have led to serious efforts towards reducing CO_(2)emissions through the CO_(2)capture from the major emission sources.CO_(2)capture using the amine functionalized a...Global warming and associated global climate change have led to serious efforts towards reducing CO_(2)emissions through the CO_(2)capture from the major emission sources.CO_(2)capture using the amine functionalized adsorbents is regard as a direct and effective way to reducing CO_(2)emissions due to their large CO_(2)adsorption amount,excellent CO_(2)adsorption selectivity and lower energy requirements for adsorbent regeneration.Moreover,large number of achievements on the amine functionalized solid adsorbent have been recorded for the enhanced CO_(2)capture in the past few years.In view of this,we review and analyze the recent advances in amine functionalized solid adsorbents prepared with different supporting materials including mesoporous silica,zeolite,porous carbon materials,metal organic frameworks(MOF)and other composite porous materials.In addition,amine functionalized solid adsorbents derived from waste resources are also reviewed because of the large number demand for cost-effective carbon dioxide adsorbents and the processing needs of waste resources.Considering the importance of the stability of the adsorbent in practical applications,advanced research in the capture cycle stability has also been summarized and analyzed.Finally,we summarize the review and offer the recommendations for the development of amine-based solid adsorbents for carbon dioxide capture.展开更多
Tetra-bromo-methyl-resorcin[4]arene cavitands were synthesized and C-2 position amine functionalized to obtain C-propyl-o-toluidine-methyl-resorcin[4]arene cavitand 4, and the crystal containing one solvate molecule o...Tetra-bromo-methyl-resorcin[4]arene cavitands were synthesized and C-2 position amine functionalized to obtain C-propyl-o-toluidine-methyl-resorcin[4]arene cavitand 4, and the crystal containing one solvate molecule of ethanol was obtained in a dichloromethane-ethanol solvent system, its structure crystallized in the monoclinic space group P2<sub>1</sub>/n, with a = 12.521(3) Å, b = 21.738(6) Å, c = 25.353(6) Å, α = 90˚, β = 102.372(4)˚, γ = 90˚, and Z = 4. The compound was determined by single-crystal X-ray diffraction and characterized by <sup>1</sup>H NMR, FT-IR and elemental analyses.展开更多
Adsorptive polyethesulfone(PES)membranes were prepared by intercalation of powder activated carbon(PAC)with and without functionalization.Accordingly,PAC was aminated with 1,5-diamino-2-methylpentane,and the physicoch...Adsorptive polyethesulfone(PES)membranes were prepared by intercalation of powder activated carbon(PAC)with and without functionalization.Accordingly,PAC was aminated with 1,5-diamino-2-methylpentane,and the physicochemical properties of the functionalized PAC were analyzed.Intercalation of PAC within the PES scaffold changed the porosity and mean pore size of the aminated membrane(AC-NH2)from 52.6%to 92.5%and from 22.6 nm to 3.5 nm,respectively.The effect of temperature on the performance of the modified mem-branes was monitored by the flux and chemical oxygen demand(COD)removal of leachate.At ambient tempera-ture,the COD removal of the neat,AC-containing,and AC-NH2 membranes was 47%,52%,and 58.5%,respec-tively.A similar increment was obtained for the membrane flux,which was due to the synergistic effect of the high porosity and large number of hydrophilic functional groups.The experimental leachate adsorption data were analyzed by Langmuir,Freundlich,and Dubinin-Radushkevich isotherm models.For all membranes,the significant thermodynamic parameters(ΔH,ΔS,and ΔG)were calculated and compared.The isosteric heat of adsorption was lower than 80 kJ·mol^-1,indicating that the interaction between the membranes and the leachate is mainly physical,involving weak van der Waals forces.展开更多
基金supported by the Shanghai Agricultural Science and Technology Program (2022-02-08-00-12-F01176)he National Natural Science Foundation of China (52006135)
文摘Direct air capture(DAC)of CO_(2)plays an indispensable role in achieving carbon-neutral goals as one of the key negative emission technologies.Since large air flows are required to capture the ultradilute CO_(2)from the air,lab-synthesized adsorbents in powder form may cause unacceptable gas pressure drops and poor heat and mass transfer efficiencies.A structured adsorbent is essential for the implementation of gas-solid contactors for cost-and energy-efficient DAC systems.In this study,efficient adsorbent poly(ethyleneimine)(PEI)-functionalized Mg-Al-CO_(3)layered double hydroxide(LDH)-derived mixed metal oxides(MMOs)are three-dimensional(3D)printed into monoliths for the first time with more than 90%adsorbent loadings.The printing process has been optimized by initially printing the LDH powder into monoliths followed by calcination into MMO monoliths.This structure exhibits a 32.7%higher specific surface area and a 46.1%higher pore volume,as compared to the direct printing of the MMO powder into a monolith.After impregnation of PEI,the monolith demonstrates a large adsorption capacity(1.82 mmol/g)and fast kinetics(0.7 mmol/g/h)using a CO_(2)feed gas at 400 ppm at 25℃,one of the highest values among the shaped DAC adsorbents.Smearing of the amino-polymers during the post-printing process affects the diffusion of CO_(2),resulting in slower adsorption kinetics of pre-impregnation monoliths compared to post-impregnation monoliths.The optimal PEI/MeOH ratio for the post-impregnation solution prevents pores clogging that would affect both adsorption capacity and kinetics.
基金supported by the National Natural Science Foundation of China(21878200 and 21676174)International S&T Cooperation Program of Shanxi province(201703D421038)+1 种基金Shanxi Scholarship Council of China(2017-036)Joint Fund of Shanxi Provincial Coal Seam Gas(2015012019)。
文摘Global warming and associated global climate change have led to serious efforts towards reducing CO_(2)emissions through the CO_(2)capture from the major emission sources.CO_(2)capture using the amine functionalized adsorbents is regard as a direct and effective way to reducing CO_(2)emissions due to their large CO_(2)adsorption amount,excellent CO_(2)adsorption selectivity and lower energy requirements for adsorbent regeneration.Moreover,large number of achievements on the amine functionalized solid adsorbent have been recorded for the enhanced CO_(2)capture in the past few years.In view of this,we review and analyze the recent advances in amine functionalized solid adsorbents prepared with different supporting materials including mesoporous silica,zeolite,porous carbon materials,metal organic frameworks(MOF)and other composite porous materials.In addition,amine functionalized solid adsorbents derived from waste resources are also reviewed because of the large number demand for cost-effective carbon dioxide adsorbents and the processing needs of waste resources.Considering the importance of the stability of the adsorbent in practical applications,advanced research in the capture cycle stability has also been summarized and analyzed.Finally,we summarize the review and offer the recommendations for the development of amine-based solid adsorbents for carbon dioxide capture.
文摘Tetra-bromo-methyl-resorcin[4]arene cavitands were synthesized and C-2 position amine functionalized to obtain C-propyl-o-toluidine-methyl-resorcin[4]arene cavitand 4, and the crystal containing one solvate molecule of ethanol was obtained in a dichloromethane-ethanol solvent system, its structure crystallized in the monoclinic space group P2<sub>1</sub>/n, with a = 12.521(3) Å, b = 21.738(6) Å, c = 25.353(6) Å, α = 90˚, β = 102.372(4)˚, γ = 90˚, and Z = 4. The compound was determined by single-crystal X-ray diffraction and characterized by <sup>1</sup>H NMR, FT-IR and elemental analyses.
基金the funding support of Babol Noshirvani University of Technology through Grant program No.BNUT/389026/97.
文摘Adsorptive polyethesulfone(PES)membranes were prepared by intercalation of powder activated carbon(PAC)with and without functionalization.Accordingly,PAC was aminated with 1,5-diamino-2-methylpentane,and the physicochemical properties of the functionalized PAC were analyzed.Intercalation of PAC within the PES scaffold changed the porosity and mean pore size of the aminated membrane(AC-NH2)from 52.6%to 92.5%and from 22.6 nm to 3.5 nm,respectively.The effect of temperature on the performance of the modified mem-branes was monitored by the flux and chemical oxygen demand(COD)removal of leachate.At ambient tempera-ture,the COD removal of the neat,AC-containing,and AC-NH2 membranes was 47%,52%,and 58.5%,respec-tively.A similar increment was obtained for the membrane flux,which was due to the synergistic effect of the high porosity and large number of hydrophilic functional groups.The experimental leachate adsorption data were analyzed by Langmuir,Freundlich,and Dubinin-Radushkevich isotherm models.For all membranes,the significant thermodynamic parameters(ΔH,ΔS,and ΔG)were calculated and compared.The isosteric heat of adsorption was lower than 80 kJ·mol^-1,indicating that the interaction between the membranes and the leachate is mainly physical,involving weak van der Waals forces.