Vapor−Liquid Equilibria for the Binary System Difluoromethane (HFC-32) + Propane (HC-290) at Seven Temperatures [(268.15, 278.15, 283.15, 288.15, 298.15, 308.15, and 318.15) K]

Isothermal vapor−liquid equilibria for the binary mixtures of difluoromethane (HFC-32) + propane (HC-290) were measured at (268.15, 278.15, 283.15, 288.15, 298.15, 308.15, and 318.15) K. The experiments were carried out using a circulation-type equilibrium apparatus with the measurement of temperature, pressure, and the compositions of the liquid and vapor phases. The experimental data were correlated with the Peng−Robinson equation of state using the Wong and Sandler mixing rules and the Carnahan−Starling−Desantis equation of state. Calculated results with these equations showed good agreement with the experimental data, but the Peng−Robinson equation of state gave more accurate calculations for the binary systems. It was found that this system has a very strong positive azeotrope for all the temperature range studied here.