Solubility determination and mixing thermodynamic properties of R1243zf in two 1-butyl-3-methyl-imidazolium based ionic liquids

Abstract

3,3,3-Trifluoropropene (R1243zf), as a new-type hydrofluoro-olefin refrigerant with extremely low GWP and thermophysical properties similar to R134a, has received more and more attention. Ionic liquids (ILs) with 1-butyl-3-methyl-imidazolium ([BMIM]+) cation are a promising kind of absorbent in absorption refrigeration cycle (ARC) owing to their low viscosity level and good stability. Towards better understanding the phase behavior of R1243zf/[BMIM]+ IL mixtures and promoting their application in ARC, the solubilities of R1243zf in [BMIM][TFO] and [BMIM][PF6] were experimentally determined using isochoric saturation method in this work. The non-random two liquid (NRTL) and Krichevsky-Kasarnovsky (K-K) model were utilized to correlate the experimental data, and both models exhibited reasonable results. In addition, the dissolution thermodynamic properties (enthalpy, entropy and Gibbs energy) and Henry’s law constants of R1243zf in the two ILs were calculated, and the variation with solubility was analyzed. Furthermore, the absorption capacities of [BMIM][TFO] and [BMIM][PF6] to different refrigerants were compared based on the reported data in the literatures.