Measurement of Phase Equilibrium for R-1233zd(E) with Three Pure Esters between 298.15 and 343.15 K

The increasing concerns of the global warming impact of traditional refrigerants (R-410a, R-245fa, R-134a, R-404a, etc.) drive the requirement for substitutes more compelling. Due to the remarkable properties (near-zero ozone depletion potential, ultralow global warming potential, nonflammable, nontoxic, high normal boiling point, etc.), trans-1-chloro-3,3,3-trifluoropropene (R-1233zd(E)) is attracting a great deal of attention in high-temperature heat pumps, chillers, and organic Rankine cycles. To increase the phase-equilibrium database for R-1233zd(E) with lubricants, the vapor-liquid phase equilibrium was measured for R-1233zd(E) in three pure polyol esters (PEC4, PEC6, and PEC8) from 298.15 to 343.15 K using an isochoric saturation method. Phase equilibrium of R-1233zd(E)/oil mixtures was successfully correlated by the NRTL model. The results show that the solubilities increase with increasing pressure and decrease with rising temperature. In addition, no liquid-liquid phase and vapor-liquid-liquid split were found. The solubilities of R-1233zd(E) in different PEC oils indicate that the solubility order increases from PEC4 to PEC8.