Vapor–Liquid Equilibrium Measurements of Difluoromethane + [Emim]OTf, Difluoromethane + [Bmim]OTf, Difluoroethane + [Emim]OTf, and Difluoroethane + [Bmim]OTf Systems

Abstract

Solubility behaviors of binary difluoromethane (HFC-32) and 1,1-difluoroethane (HFC-152a) systems with ionic liquids (ILs) 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([Emim]OTf) and 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([Bmim]OTf) have been studied by using an isothermal synthetic apparatus at temperatures (273.15, 298.15, 323.15 and 348.15) K and at pressures (0.04 to 1.0) MPa. Experimental solubility data were successfully correlated with the nonrandom two-liquid (NRTL) activity coefficient model. It was found that the solubility of hydrofluorocarbons (HFCs) in ILs is affected by the change of alkyl chain length in the cation.