Measurement and Correlation of Vapor–Liquid Equilibrium for Difluoromethane (R32) + trans-1,1,1,4,4,4-Hexafluoro-2-butene (R1336mzz(E)) at Temperatures from 302.85 to 342.69 K

Abstract

Heat pump, organic Rankine cycle, or refrigeration cycle require the knowledge of phase equilibrium properties, particularly if multicomponent systems are considered. In this study, we present new experimental data of vapor–liquid equilibrium (VLE) for the binary systems of difluoromethane (R32) + trans-1,1,1,4,4,4-hexafluoro-2-butene (R1336mzz(E)) at temperatures from 302.85 to 342.69 K. The VLE data were measured by a “static-analytic”-type apparatus which was equipped with two electromagnetic capillary samplers (ROLSI, Armines’s patent). The experimental VLE data were correlated by the Peng–Robinson (PR) equation of state (EoS) associated with the Mathias and Copeman (MC) alpha function and van der Waals (vdW) mixing rules. The modeling results of the PRMC-vdW model were in good agreement with the measured data. The VLE data were compared with the prediction model, namely, PPR78, and it was found that the PPR78 model overestimated the bubble pressure of R32 + R1336mzz(E). Moreover, the binary interaction parameter (BIP) was also correlated considering a second-order polynomial expression between the BIP (k_ij) and acentric factor (ω) for R1336mzz(E)-contained binary mixtures.