Vapor-liquid equilibria for the 1,1,1-trifluoroethane (HFC-143a)+1,1,1,2-tetrafluoroethane (HFC-134a) system

A vapor-liquid equilibrium apparatus has been developed and used to obtain data for the binary HFC-143a + HFC-134a system. Fifty-four equilibrium data are obtained for the HFC-143a + HFC-134a system over the temperature range from 263.15 to 313.15 K at 10 K intervals. The experimental data were corr elated with the Carnahan-Starling-De Santis (CSD) and Peng-Robinson (PR) eq uations of state. Based upon the present data, the binary interaction param eters for the CSD and PR equations of state were calculated for six isother ms for the HFC-143a + HFC-134a system. The binary interaction parameters fo r both equations of state were fitted by a linear equation as a function of temperature. The present data were in good agreement with the calculated r esults from the CSD equation of state, and the deviations were less than 1. 0% with the exception of two points.