PREDICTION OF VAPOR-LIQUID-EQUILIBRIUM WITH THE LCVM MODEL - A LINEAR COMBINATION OF THE VIDAL AND MICHELSEN MIXING RULES COUPLED WITH THE ORIGINAL UNIFAC AND THE T-MPR EQUATION OF STATE

A new mixing rule, a linear combination of the Vidal and Michelsen rules, for the attractive term parameter in cubic equations of state (EoS) has been developed. This mixing rule, coupled with a translated and modified Peng-Robinson EoS and the original UNIFAC, leads to the LCVM model which provides successful prediction of vapor-liquid equilibria (VLE) of nonpolar and polar systems at low and high pressures. This also applies to systems of dissimilar component size, such as those containing gases (C2H6, CO2 and CH4) with large n-alkanes, where other EoS/G(E) predictive models, such as MHV2 and PSRK, perform poorly.