Isothermal Vapor−Liquid Equilibria for the Binary System of Carbon Dioxide (CO2) + 1,1,1,2,3,3,3-Heptafluoropropane (R-227ea)

Abstract

Isothermal vapor−liquid equilibrium (VLE) data for the binary mixture of carbon dioxide (CO2) + 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) were measured at six evenly spaced temperatures of (278.15, 288.15, 298.15, 308.15, 318.15, and 328.15) K. The data in the two-phase region were measured by using a circulation-type equilibrium apparatus in which both vapor and liquid phases are continuously recirculated. The experimental data were correlated with the Peng−Robinson equation of state (PR-EoS) using the Wong−Sandler (W−S) mixing rules combined with the nonrandom two-liquid (NRTL) excess Gibbs free energy model. The calculated values with the PR-EoS using the W−S mixing rules show good agreement with the experimental data.