CO2 was absorbed by 1-aminopropyl-3-methylimidazolium bromine([APMIm][Br])as chemical reaction. The absorbents were prepared by supporting ionic liquids on porous silica gel through the impregnation-evaporation method

and pore structure and absorption capacity were characterized with specific surface pore adsorption apparatus and thermogravimetric analysis

respectively. CO2 absorption was conducted under the following conditions: 10% to 50% of ionic liquids loading

303.15 K to 323.15 K of temperature

and 10%

30%

50% of CO2 in mixed gas. The results suggested that absorption rate was fastest when film thickness of ionic liquids on the silica gel was 86 nm

and was little affected by the change of CO2 concentration and temperature. Equilibrium absorption amount reached 80% of the theoretical uptake in 50% CO2 system

and was reducing with increasing temperature. However

absorption rate and capacity decreased obviously as film thickness of ionic liquid exceeded 230 nm. The properties of supported ionic liquid absorbent remained unchanged after recycling three times

showing the prospect of industrial use.