The use of amine-based absorbers,such as N-methyldiethanolamine(MDEA),for CO_(2) capture presents a promising strategy for emission reduction as global warming intensifies.However,high energy consumption and limited a...The use of amine-based absorbers,such as N-methyldiethanolamine(MDEA),for CO_(2) capture presents a promising strategy for emission reduction as global warming intensifies.However,high energy consumption and limited absorption/desorption efficiencies constrain its application.To address these challenges,this study developed a composite catalyst derived from fly ash(FA),which is alkali-modified and incorporates nickel(Ni) and iron(Fe) elements,with the aim of enhancing CO_(2) absorption and desorption performance while reducing energy consumption.Experimental results indicated that the Ni/FA-AM catalyst significantly improved adsorption and absorption efficiencies,achieving an 8% increase in capacity,a 63% increase in peak adsorption rate,and a reduction of 6000 s in saturation time.Studies conducted in a wetted-wall column revealed that the absorption process predominantly occurs in the liquid phase.Additionally,the catalyst demonstrated a 19% improvement in desorption performance,a 10% increase in peak desorption rate,and a 24% reduction in energy consumption,while maintaining stability over five consecutive cycles.The alkali-modified and Ni/Fe-enriched fly ash was confirmed to form active acid-base sites,facilitating the formation and disappearance of bicarbonate,thereby enhancing CO_(2) capture efficiency.This was validated through XRD,BET,TPD,PY-IR,TEM,and FTIR with13C NMR characterization.This study highlights the potential of modified fly ash as a low-cost and efficient catalyst for CO_(2) capture.展开更多
基金supported by the National Natural Science Foundation of China (52106009 and 52206011)the Natural Science Foundation of Hebei Province (E2021502024)the Fundamental Research Funds for the Central Universities (2024MS170,2023MS142,2022MS109)。
文摘The use of amine-based absorbers,such as N-methyldiethanolamine(MDEA),for CO_(2) capture presents a promising strategy for emission reduction as global warming intensifies.However,high energy consumption and limited absorption/desorption efficiencies constrain its application.To address these challenges,this study developed a composite catalyst derived from fly ash(FA),which is alkali-modified and incorporates nickel(Ni) and iron(Fe) elements,with the aim of enhancing CO_(2) absorption and desorption performance while reducing energy consumption.Experimental results indicated that the Ni/FA-AM catalyst significantly improved adsorption and absorption efficiencies,achieving an 8% increase in capacity,a 63% increase in peak adsorption rate,and a reduction of 6000 s in saturation time.Studies conducted in a wetted-wall column revealed that the absorption process predominantly occurs in the liquid phase.Additionally,the catalyst demonstrated a 19% improvement in desorption performance,a 10% increase in peak desorption rate,and a 24% reduction in energy consumption,while maintaining stability over five consecutive cycles.The alkali-modified and Ni/Fe-enriched fly ash was confirmed to form active acid-base sites,facilitating the formation and disappearance of bicarbonate,thereby enhancing CO_(2) capture efficiency.This was validated through XRD,BET,TPD,PY-IR,TEM,and FTIR with13C NMR characterization.This study highlights the potential of modified fly ash as a low-cost and efficient catalyst for CO_(2) capture.
