Point source CO_(2) capture(PSCC)is crucial for decarbonizing various industrial sectors,while direct air capture(DAC)holds promise for removing CO_(2) directly from the air.Sorbents play a critical role in both techn...Point source CO_(2) capture(PSCC)is crucial for decarbonizing various industrial sectors,while direct air capture(DAC)holds promise for removing CO_(2) directly from the air.Sorbents play a critical role in both technologies,with their performances,efficiency,cost,etc.,largely depending on which type is used(physical or chemical).Solid amine sorbents(SAS)employed in the chemical adsorption of CO_(2) are suitable for both PSCC and DAC.SAS offer significant advantages over liquid amines such as monoethanolamine(MEA),due to their ability to perform cyclic adsorption–desorption with much lower energy requirement.The environmental concern associated with MEA can be mitigated by SAS.Support materials have a significantly important role in stabilizing amine and enhancing stability and kinetics;varieties of support materials have been screened at a laboratory scale.One promising support material is a silica gel(SG),which is commercially available and attractive for designing cost-effective sorbents for large-scale CO_(2) capture.Various impregnation methods such as physical adsorption and covalent functionalization have been employed to functionalize silica surfaces with amines.This review provided a comprehensive critical analysis of SG-based SAS for CO_(2) capture.We discussed and evaluated them in terms of their adsorption capacity,adsorption,and desorption conditions,and the kinetics involved in these processes.Finally,we proposed a few recommendations for further development of low-cost,lower carbon footprint SAS for large-scale deployment of CO_(2) capture technology.展开更多
A series of organic compounds were successfully immobilized on an N-doped graphene quantum dot (N-GQD) to prepare a multifunctional organocatalyst for coupling reaction between CO_(2)and propylene oxide (PO).The simul...A series of organic compounds were successfully immobilized on an N-doped graphene quantum dot (N-GQD) to prepare a multifunctional organocatalyst for coupling reaction between CO_(2)and propylene oxide (PO).The simultaneous presence of halide ions in conjunction with acidic-and basic-functional groups on the surface of the nanoparticles makes them highly active for the production of propylene carbonate (PC).The effects of variables such as catalyst loading,reaction temperature,and structure of substituents are discussed.The proposed catalysts were characterized by different techniques,including Fourier transform infrared spectroscopy (FTIR),field emission scanning electron microscopy/energy dispersive X-ray microanalysis (FESEM/EDX),thermogravimetric analysis (TGA),elemental analysis,atomic force microscopy (AFM),and ultraviolet–visible (UV-Vis) spectroscopy.Under optimal reaction conditions,3-bromopropionic acid (BPA) immobilized on N-GQD showed a remarkable activity,affording the highest yield of 98%at 140℃ and 106Pa without any co-catalyst or solvent.These new metal-free catalysts have the advantage of easy separation and reuse several times.Based on the experimental data,a plausible reaction mechanism is suggested,where the hydrogen bonding donors and halogen ion can activate the epoxide,and amine functional groups play a vital role in CO_(2)adsorption.展开更多
基金financial support from Business Finland 8205/31/2022the Magnus Ehrnrooth Foundation for financial support.
文摘Point source CO_(2) capture(PSCC)is crucial for decarbonizing various industrial sectors,while direct air capture(DAC)holds promise for removing CO_(2) directly from the air.Sorbents play a critical role in both technologies,with their performances,efficiency,cost,etc.,largely depending on which type is used(physical or chemical).Solid amine sorbents(SAS)employed in the chemical adsorption of CO_(2) are suitable for both PSCC and DAC.SAS offer significant advantages over liquid amines such as monoethanolamine(MEA),due to their ability to perform cyclic adsorption–desorption with much lower energy requirement.The environmental concern associated with MEA can be mitigated by SAS.Support materials have a significantly important role in stabilizing amine and enhancing stability and kinetics;varieties of support materials have been screened at a laboratory scale.One promising support material is a silica gel(SG),which is commercially available and attractive for designing cost-effective sorbents for large-scale CO_(2) capture.Various impregnation methods such as physical adsorption and covalent functionalization have been employed to functionalize silica surfaces with amines.This review provided a comprehensive critical analysis of SG-based SAS for CO_(2) capture.We discussed and evaluated them in terms of their adsorption capacity,adsorption,and desorption conditions,and the kinetics involved in these processes.Finally,we proposed a few recommendations for further development of low-cost,lower carbon footprint SAS for large-scale deployment of CO_(2) capture technology.
基金supported by Iran National Science Foundation(No.97015707)。
文摘A series of organic compounds were successfully immobilized on an N-doped graphene quantum dot (N-GQD) to prepare a multifunctional organocatalyst for coupling reaction between CO_(2)and propylene oxide (PO).The simultaneous presence of halide ions in conjunction with acidic-and basic-functional groups on the surface of the nanoparticles makes them highly active for the production of propylene carbonate (PC).The effects of variables such as catalyst loading,reaction temperature,and structure of substituents are discussed.The proposed catalysts were characterized by different techniques,including Fourier transform infrared spectroscopy (FTIR),field emission scanning electron microscopy/energy dispersive X-ray microanalysis (FESEM/EDX),thermogravimetric analysis (TGA),elemental analysis,atomic force microscopy (AFM),and ultraviolet–visible (UV-Vis) spectroscopy.Under optimal reaction conditions,3-bromopropionic acid (BPA) immobilized on N-GQD showed a remarkable activity,affording the highest yield of 98%at 140℃ and 106Pa without any co-catalyst or solvent.These new metal-free catalysts have the advantage of easy separation and reuse several times.Based on the experimental data,a plausible reaction mechanism is suggested,where the hydrogen bonding donors and halogen ion can activate the epoxide,and amine functional groups play a vital role in CO_(2)adsorption.
