(Vapour plus liquid) equilibrium measurement and correlation of the refrigerant (propane plus 1,1,1,3,3,3-hexafluoropropane) at T = (283.13, 303.19, and 323.26) K

Due to the presence of more than negligible amounts of impurities in the R290, two sets of data are presented and correlated: the first was determined disregarding the impurities in the composition measurement, assuming that the mixture was binary; the second set was obtained assuming that the mixture was quaternary, considering the two impurities detected {n-butane (R600) and isobutane (R600a)} as components of the mixtures. The results were correlated using the Camahan-Starling-De Santis equation of state. The experimental findings show a strong positive deviation from Raoult's law and the presence of an azeotropic composition at high R290 concentrations. Applying the homomorph concept, the hydrogen-bonding energy in (dimethyl ether + R236fa) was estimated using previously published results and those presented here. The v.l.e. of the system are not reported elsewhere in the literature.