Experimental Research On Functional Ionic Liquids Performance Of Absorb CO₂from Flue Gas

CO₂is the main greenhouse gas in the atmosphere, with the further spread of the greenhouse effect, the reasearch on carbon dioxide capture/conversion and utilization has become one of the most important subjects around the world. New functional ionic liquid,called as green solvent, has a low vapor pressure, low melting point, strong dissolution, a specific function and a series of excellent features, therefore theuseage of functional ionic liquid in CO₂emission reduction has caused wide attention. At the same time, the functional ionic liquid with amine function group has been deeply studied.In this paper, the one-step and two-step synthesis method was taken to synthesize eight kinds of primary amine functional ionic liquids and eight kinds of tertiaryamine functional ionic liquids. And with the help of IR and1HNMR measurement,their structures were characterized and their pruities and characteristic parameters were determined.Under atmosphere condition, CO₂absorption experiments of the functional ionicliquis were carried on the constructed on-line absorption system to get the CO₂saturation adsorption capacity, adsorption equilibrium time, and other related parametersthrough serial comprehensive comparisons. Four cases,[NH₂P-mim]Br （60%mass fraction of moisture, simplified by60%）,[NH₂P-bim]PF₆（30%）,[（CH₃）₂NP-bim][Tf₂N]（30%） and [（CH₃）₂NP-mim][Tf₂N], were selected by their CO₂adsorption propertiesfor the further characteristic research as well as CO₂regeneration ability.Selected four cases of functional ionic liquids were used to study the CO₂absorption properties from flue gas. the impact of temperature and partial pressure of CO₂, O₂, acid gases SOx and NOx and other factors on CO₂absorption, are exploredin the fourth capture. In addition, all the mechanisms of CO₂absorption under different situations have been comprehensively discussed with the help of FTIR measurement. The overall study showed that [（CH₃）₂NP-bim][Tf₂N]（30%） CO₂capture capability reached0.5707mol/mol, the absorption equilibrium and desorption time were25min and15min respectively. After5cycles the absorption ability of this ionic liquid remained0.5079mol/mol. In addition, it had strong anti-oxidation and acid gas SO_x and NO_x ability.