CO2 Solubility in Ether Functionalized Ionic Liquids on Mole Fraction and Molarity Scales

Abstract

The effect of ether functional group(s) in the cation, anion, and both of the ions in ionic liquids on physical absorption of CO2 are revisited in the present work. The solubilities of CO2 in ether functionalized ammonium and pyrrolidinium salts, [N211MEE][Tf2N], [Pyr1MOM][Tf2N], and [Pyr1MOM][FSA] were previously reported together with the corresponding alkyl analogues. In addition to such cation-modified ionic liquids, we investigate a new family of ether functionalized ionic liquids with alkoxy sulfates; [C2mim][C1(OC2)2SO4], [P444ME][C6SO4], [P444ME][C1OC2SO4], [P444ME][C1(OC2)2SO4], and [N221ME][C1(OC2)2SO4]. The CO2 solubility data on the molarity as well as the mole fraction scales are presented in a series of ether functionalized ILs with a brief overview of the previously reported results. It has become apparent that the introduction of an ether functional group in anions more effectively improves the CO2 solubilities on both the mole fraction and molarity scales than that in cations. The effects...