Vapor-Liquid Equilibrium Measurements and Modeling for the Ethane (R-170) plus 1,1,2,3,3,3-Hexafluoro-1-propene (R-1216) Binary System

Novel isothermal (p-x-y) vapor-liquid equilibrium data are reported for ethane (R-170) + 1,1,2,3,3,3-hexafluoro-1-propene (R-1216) mixtures at five temperatures in the (282.93 to 322.89) K range, at pressures up to about 4.6 MPa. The experimental data were measured using an apparatus based on the "static-analytic" method taking advantage of two electromagnetic capillary samplers for repeatable and reliable equilibrium phase sampling and handling. The experimental data are well-correlated with the "PR-MC-NRTL-WS" model constituted by the Mathias-Copeman alpha function, nonrandom two-liquid (NRTL) local composition model, and Wong-Sandler mixing rule introduced in the Peng-Robinson equation of state. The studied system did not exhibit azeotropic behavior nor liquid-liquid immiscibility over the range of investigated temperatures. Mixture critical points have been estimated from the experimental vapor-liquid equilibrium data via the extended scaling laws and the "PR-MC-NRTL-WS" model and are found to be in good agreement with the experimental isothermal phase envelopes.