Vapor–liquid equilibria predictions at high-pressures with the Huron–Vidal mixing rule

Abstract

In this work we propose an equation of state (EoS) framework that uses the Huron–Vidal (HV) mixing rule to correlate binary low-pressure vapor–liquid equilibria (VLE) for several non-ideal mixtures. The parameters from the data reduction procedure are used for VLE predictions at high-pressures. The EoS applied is the Stryjek–Vera modification of the Peng–Robinson model. The excess Gibbs energy ( G E) model incorporated in the HV mixing rule is based on one-fluid theory. Two parameters are assigned per binary mixture. The binary mixture size parameter is replaced by the mean of the pure component molecular size parameters. A single energy parameter is assigned per binary pair, which is regressed from low-pressure experimental data. Good predictions of the model are shown for VLE at high temperatures and pressures and for a few ternary systems. A physical interpretation of the energy parameters is revealed in terms of the relative strength of like to unlike interactions in the mixture. A comparison for two ternary systems is shown with the Reformulated Wong–Sandler (RWS) [AIChE J. 32 (1992) 671] mixing rule in its predictive form.