Vapor−Liquid Equilibria for Isobutane + Pentafluoroethane (HFC-125) at 293.15 to 313.15 K and + 1,1,1,2,3,3,3-Heptafluoropropane (HFC-227ea) at 303.15 to 323.15 K

Abstract

Isothermal vapor−liquid equilibria were determined for binary systems of pentafluoroethane (HFC-125) + isobutane (R600a) at 293.15, 303.15 and 313.15 K and 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) + isobutane (R600a) at 303.15, 313.15 and 323.15 K in a circulation-type equilibrium apparatus. The experimental data were well correlated with the Peng−Robinson−Stryjek−Vera (PRSV) equation of state combined with the NRTL excess Gibbs free-energy model and Huron-Vidal original mixing rules.