Further validation of a set of quadrupolar potential models for ethylene and propylene from the prediction of some binary mixture vapor-liquid equilibria by Gibbs-ensemble molecular simulation

A set of two-center Lennard-Jones plus point quadrupole (2CLJQ) effective pair potential models for ethylene and propylene, that have already been shown to be capable of fitting the saturated densities, the vapor pressures, and the enthalpies of vaporization of the pure liquids, is tested for vapor-liquid equilibrium (VLE) of mixtures in this work. Monte Carlo simulations in the Gibbs ensemble were carried out in order to obtain VLE data for the binary systems methane+ethylene, ethylene+ethane, and ethane+propylene. No binary adjustable parameters were needed to compute the unlike-pair Lennard-Jones interactions in the binary systems. Simulation results were found to be in good agreement with the experimental data available for pressure and phase composition of the binary systems methane+ethylene at 150 and 190 K, ethylene+ethane at 233.15 and 255.37 K and ethane+propylene at 277.59 and 310.93 K.