Phase Equilibrium Study of Hexafluoropropylene Oxide and Propane System at (283.05, 303.05, 323.05) K: Experimental Measurements and Thermodynamic Modeling

This study presents the vapor–liquid equilibrium data of two fluorinated systems: R116 + propane, as a test system to validate both the experimental setup and the procedure, and hexafluoropropylene oxide + propane, as a novel system. Measurements of vapor–liquid equilibrium data were achieved via a static-analytical setup equipped with the ROLSI device for phase sampling and gas chromatography for composition analysis. The expanded uncertainties for temperature, pressure, and composition measurements were estimated at 0.02 K, 0.008 MPa, and 0.006, respectively. Thermodynamic modeling of the experimental VLE data was via the direct method, using the Peng–Robinson equation of state with the Mathias–Copeman α function and the Wong-Sandler mixing rule, incorporating the nonrandom two-liquid activity coefficient model. The deviations AAD_xy and Bias_xy between the measured and the computed data were determined to be less than 2%, indicating a good agreement between the model and the measurements. The successful correlation of the experimental data demonstrates the reliability of the experimental approach used and provides valuable insights into the thermodynamic behavior of the investigated fluorinated systems. The hexafluoropropylene oxide + propane system was found to exhibit azeotropic behavior across the investigated isotherms, with azeotropic compositions not varying significantly with temperature.