Study On The Performance Of Supported KIT-6 And Sepiolite Catalyst For Catalytic Desorption Of Rich CO₂-loaded Amine Solution

Due to the extensive use of fossil energy in the continuous development of human society,a large amount of greenhouse gas CO₂has been emitted,which has caused a series of environmental problems.The organic amine chemical absorption method is currently the most common and efficient CO₂capture method.However,the main bottleneck of the current large-scale use of this method is that the energy consumption of solvent regeneration is too high.Numerous studies have shown that the addition of solid acid-base catalysts can effectively reduce the thermal energy consumption during solvent regeneration.Based on this background,a variety of metal oxide supported mesoporous molecular sieves KIT-6 and sepiolite catalysts were prepared in this study and used to catalyze the regeneration of CO₂amine solution.The structure and physicochemical properties of the prepared catalysts were characterized by XRD,FT-IR,BET,Py-IR,NH₃-TPD,and the possible CO₂catalytic desorption mechanism was explored.In this study,traditional monoethanolamine（MEA）solution was used to explore the catalytic CO₂desorption performance（relative CO₂loading,desorption rate,desorption amount,relative desorption energy consumption and cycle stability）of different catalysts at 100°C.The main research contents and conclusions are as follows:（1）Four catalysts,KIT-6,Fe₂O₃-KIT-6,Ni O-KIT-6 and Cu O-KIT-6,were prepared by hydrothermal synthesis and impregnation,and their catalytic performance in the regeneration of CO₂-rich amine solution was explored.The results show that the addition of the four catalysts can effectively reduce the relative CO₂desorption energy consumption,and Cu O-KIT-6 shows the best catalytic performance,which can reduce the relative desorption energy consumption by 33.4%.In addition,the influence of the addition amount of Cu O-KIT-6 catalyst on the catalytic regeneration performance and its cycle stability were also investigated.When the mass ratio of Cu O-KIT-6 catalyst to MEA solution is 1.25 wt%,Cu O-KIT-6 shows relatively good catalytic desorption performance and good cycle stability.（2）Two catalysts,Fe₂O₃-SEP and Cu O-SEP,were prepared by impregnation method to explore their catalytic regeneration performance of CO₂-rich amine solution.The results show that the addition of the three SEP series catalysts can effectively reduce the relative CO₂desorption energy consumption.Among them,Fe₂O₃-SEP shows the best catalytic performance,which can reduce the relative desorption energy consumption by 46.0%,and shows good catalytic performance in 6absorption and desorption cycles.（3）Combined with the structure and physicochemical properties obtained from the characterization of the catalyst,by analyzing the structure-activity relationship between it and the catalytic desorption performance of CO₂,the results show that the larger the mesoporous specific surface area of the loaded catalyst and the more Br（?）nsted acid sites（B acid）,the better the catalytic desorption performance of CO₂.In the process of CO₂desorption catalyzed by solid acid catalyst,B acid can provide acid protons for the breaking reaction of carbamate in the desorption process,while Lewis acid sites（L acid）can further promote the breaking process of carbamate.Therefore,this study found a new type of supported catalyst to promote the regeneration of amine solution,reduce the energy consumption of CO₂desorption,improve the desorption performance of amine solution,and finally make the technology more feasible technically and economically.It is also proved that adding a catalyst to the CO₂capture process of the organic amine method can make the method low energy consumption and efficient capture of CO₂,and the application prospect is broad.