CALCULATION OF VAPOR-LIQUID-EQUILIBRIUM OF MULTICOMPONENT MIXTURES USING A MEAN-FIELD LATTICE-GAS MODEL

In this paper, the mean-field lattice-gas model by Koningsveld and Kle intjens is applied to describe vapor-liquid equilibrium. For petroleum or petroleum fractions, one has to consider additionally the multicom ponent character of the system. To handle the problems with the large number of similar components, continuous thermodynamics has been often proved to be a convenient method. Here, the composition of the multic omponent mixture is described by continuous distribution functions. On this basis, for systems consisting of a petroleum fraction and a pola r component, equilibrium-flash-vaporization curves at low pressures ar e predicted. The parameters needed were fitted to phase equilibrium da ta of pure substances and binary mixtures. There is a reasonable agree ment between calculated and experimental results. (C) 1998 Elsevier Sc ience B.V. All rights reserved.