Vapor–liquid equilibrium of difluoromethane +1,1,1,2-tetrafluoroethane systems over a temperature range from 258.15 to 343.15 K

Isothermal vapor–liquid equilibrium data for the binary system of difluoromethane (HFC-32) +1,1,1,2-tetrafluoroethane (HFC-134a) were measured at temperature from 258.15 to 343.15 K in a circulation-type equilibrium apparatus. The experimental data were correlated with the Peng–Robinson–Stryjek–Vera equation of state using the Wong–Sandier mixing rule. The overall deviation of the pressure by the PRSV equation of state was 0.940%, and the average deviation of vapor phase composition by the PRSV equation of state was 0.0063.