Vapor-liquid equilibria from an improved hard convex body expansion method. Part II. Non-polar mixtures

Abstract

Chen, Y.-C. and Chen, Y.-P., 1993. Vapor-liquid equilibria from an improved hard convex body expansion method. Part II. Non-polar mixtures. Fluid Phase Equilibria, 86: 87-109. This study presents an improved vapor-liquid equilibrium calculation method for non-polar mixtures by employing the hard convex body expansion (HCBE) theory. The repulsive contribution to thermodynamic properties is determined at a given density, where the pseudo-volume parameter is calculated by a modified one-fluid theory. A generalized corresponding states equation with two reference fluids is used to calculate the attractive contribution. A combined model applying the van der Waals one-fluid (VDW-1) and the mean density approximation (MDA) theories has been used to determine the pseudo-energy parameter for the attractive property calculations. This work is an extension of our previous studies on non-polar pure fluids in which we have correlated the geometrical acentric factors. The calculation results are very satisfactory and are better than those obtained by applying only the VDW-1 or MDA method for the attractive property computations. Henry's constants of light hydrocarbons in heavy alkanes can also be predicted successfully by the method of this work. ? 1993.