Industrial & Engineering Chemistry Research, Vol.50, No.8, 4761-4768, 2011
Experimental Measurement of Vapor Pressures and Densities at Saturation of Pure Hexafluoropropylene Oxide: Modeling Using a Crossover Equation of State
Hydrofluoroalkenes, like hexafluoropropylene, can be considered as new working fluids for refrigeration systems and consequently volumetric and critical property data are required. In this study, a vibrating tube densitometer technique was used to determine densities at nine different temperatures between (263 and 358) K, and pressures between (0.04 and 15) MPa. The experimental uncertainties are +/- 0.0003 and +/- 0.0006 MPa for pressure, +/- 0.02 K for temperature, +/- 0.5% (relative) for vapor densities, and +/- 0.05% for liquid densities. A different equipment based on static method is used for the determination of pure component vapor pressures for temperatures between (231 and 359) K. The experimental uncertainties are +/- 0.0005 MPa for pressure and +/- 0.02 K for the temperature. Critical properties have been determined by direct measurement and also from utilization of experimental densities considering the asymptotic scaling law behavior. The Patel-Teja and crossover Patel-Teja equations of state are used to correlate the data.