CO2 Solubility and Physical Properties of Two Containing Fluorine Functional Ionic Liquids

Two containing fluorine functional ionic liquids (ILs) (1-aminoethyl-3-methyl imidazolium trifluoroacetic acid salt ([aemim] [CF3COO]) and 1-aminoethyl-3-methyl imidazolium trifluoromethane sulfonic acid salt ([aemim] [TfO])) were synthesized and the samples were characterized by means of FTIR, 1HNMR respectively. The densities, viscosities, and electrical conductivities of the two samples were measured over the temperature range T = (303.15-333.15) K at atmospheric pressure. The solubility of CO2 in the two samples were investigated at temperature from 303.15 to 333.15 K and pressure from 0 to 7.14 MPa. Results showed that the maximum solubility of CO2 in [aemim] [TfO] was 0.759 (mole fraction) at 7.01 MPa and 323.15K, and the which of [aemim] [CF3COO] was 0.646 at 6.49 MPa and 313.15 K. The influence of the temperature and CO2 partial pressure on the process of CO2 absorption was discussed. The CO2 solubilities in different ILs were also compared. The Henry's constants and infinite dilution partial molar volumes for the ILs+ CO2 systems were obtained.