Solubilities of Carbon Dioxide in Eutectic Mixtures of Choline Chloride and Dihydric Alcohols

The solubilities of CO 2 in eutectic mixtures containing choline chloride and dihydric alcohols (including 1,4-butanediol, 2,3-butanediol, and 1,2-propanediol) with a molar ratio of choline chloride to dihydric alcohol of 1:3 and 1:4 were measured at 293.15 K, 303.15 K, 313.15 K, and 323.15 K under pressures up to 600.0 kPa using an isochoric saturation method. Henry’s constant and the dissolution Gibbs free energy, enthalpy, and entropy changes of CO 2 solvation were obtained by correlating the experimental data. The solubility of CO 2 in the mixtures increased linearly with the increasing pressure or the decreasing temperature. The enthalpies of solution were negative at all conditions.