Experimental Investigation of Vapor-Liquid Equilibrium for 2,3,3,3-Tetrafluoropropene (HFO-1234yf) + trans-1,3,3,3-Tetrafluoropropene (HFO-1234ze(E)) at Temperatures from 284 to 334 K

The vapor-liquid equilibrium for the binary system (HFO-1234yf + HFO-1234ze(E)) has been investigated using a liquid-recirculation apparatus from 284 to 334 K. The Peng-Robinson equation of state with the Mathias-Copeman alpha function (PR-MC), combined with Wong-Sandler (WS) mixing rule and simplified Wong-Sandler (WS_S) mixing rule, respectively, was chosen to correlate all of the experimental data. The results correlated by PR-MC + WS + NRTL and PR-MC + WS_S + NRTL models showed a good agreement with the experimental data; the average absolute relative deviation of pressure (AARDp) was within 0.5%, and the average absolute deviation of the mole fraction of HFO-1234yf in the vapor phase (AADy(1)) was less than 0.002. This system exhibited no azeotropic behavior within the investigated temperature range. In addition, the relative volatilities of the system at each temperature were obtained.