Solubility behavior of 3, 3, 3-trifluoropropene in 1-hexyl-3-methyl-Imidazolium hexafluorophosphate and 1-octyl-3-methyl-imidazolium hexafluorophosphate

Due to low global warming potential and ozone depletion potential, 3, 3, 3-trifluoropropene (HFO1243zf or R1243zf) has attracted much attention. 1-Hexyl-3-methyl-imidazolium hexafluorophosphate ([HMIM] [PF6]) and 1-octyl-3-methyl-imidazolium hexafluorophosphate ([OMIM][PF6]) with strong absorbability and hydrophobicity are assumed as potential absorbents in absorption refrigeration cycle. In this work, the solubility of R1243zf in [HMIM][PF6] and [OMIM][PF6] was measured based on isochoric saturation method under seven temperatures (283.15 K, 293.15 K, 303.15 K, 313.15 K, 323.15 K, 333.15 K and 343.15 K). The experimental solubility data was correlated using the non-random two liquid (NRTL) and Krichevsky-Kasarnovsky (K-K) model, and both models showed reasonable results. In addition, the Henry's law constants and mixing thermodynamic properties (mixing enthalpy, entropy and Gibbs energy) for R1243zf + [HMIM][PF6] and R1243zf + [OMIM][PF6] solutions were computed, and their variation with solubility was analyzed. Besides, the dissolving performances of different HFOs (R1234ze(E), R1243zf and R1234yf) in [HMIM][PF6] and [OMIM][PF6] were compared and analyzed on basis of the published data in the literature.

Automated summary

This study measured the solubility of HFO1243zf in [HMIM][PF6] and [OMIM][PF6], and correlated the experimental data using appropriate models. The mixing thermodynamic properties of R1243zf + [HMIM][PF6] and R1243zf + [OMIM][PF6] solutions were computed, and the dissolving performances of different HFOs were compared and analyzed.