Kinetics of CO2 absorption into aqueous 1-ethyl-3-methylimidazolium glycinate solution

•The effect factors of CO2 absorption and physicochemical parameters were discussed.•Aqueous [C2mim][Gly] solution was characterized for CO2 absorption purpose.•The CO2 absorption into aqueous [C2mim][Gly] solution was the fast pseudo-first order reaction.•The reaction rate constant (k2) and activity energy were calculated out.•As carbon chain linked with imidazole ring increased, solubility of CO2 and activity energy increased.

The kinetic of CO2 absorption into aqueous 1-ethyl-3-methylimidazolium glycinate ([C2mim][Gly]) solution was investigated using a double stirred-cell absorber. Density and viscosity of the [C2mim][Gly]) solution were determined, then diffusion coefficient (DCO2)DCO2 and solubility of CO2 were estimated. The effects of [C2mim][Gly] concentration, absorption temperature and CO2 concentration in bulk gas were studied. Calculated results proved that CO2 absorption into aqueous [C2mim][Gly] solution was carried out according to a fast pseudo-first order reaction regime. Hatta number (Ha), the enhancement factor (E  ), the overall reaction rate constant (kOVkOV) and the second-order rate constant (k2) were calculated by gas–liquid two-film theory. The result showed that E   was linear with CILs1/2, and the second-order rate constant was expressed as following equation: k2=6.041×106exp-2801T.