Isothermal vapor–liquid equilibrium data for the ethylene + 1,1,2,3,3,3-hexafluoro-1-propene binary system between 258 and 308 K at pressures up to 4.56 MPa

Isothermal vapor–liquid equilibrium data are reported for ethylene + 1,1,2,3,3,3-hexafluoro-1-propene mixtures at six temperatures in the 258.35–307.38 K range, and pressures up to 4.56 MPa. The experimental data were measured using an apparatus based on the “static-analytic” method equipped with a movable ROLSI™ capillary sampler for repeatable and reliable equilibrium phase sampling and handling. The isothermal P–x–y data are well correlated with a model comprised of the Peng–Robinson equation of state containing the Mathias–Copeman alpha function, Wong–Sandler mixing rule, and NRTL local composition model. The combined model is termed “PR-MC-WS-NRTL”. The studied system does not exhibit azeotropic behavior nor liquid–liquid immiscibility over the range of investigated temperatures. Mixture critical points are calculated from the experimental vapor–liquid equilibrium data via the extended scaling laws and the PR-MC-WS-NRTL model, and are found to be in good agreement with the experimental isothermal phase envelopes.