Calculation of Equilibrium for Multicomponent Mixtures Using the Parameters of Models for Binary Pairs of Pure Components

Abstract

An algorithm and an application software package have been developed for calculating the vapor–liquid equilibrium of multicomponent mixtures using the optimal parameters of equilibrium models (namely, the Wilson, NRTL, and UNIQUAC models) for binary pairs of the pure components of a mixture. The parameters of the models have been optimized by extremum localization, simple iteration, and certain other methods at the minimum of the optimization criterion, i.e., the sum of the squared deviations between experimental and calculated values for the equilibrium compositions of the vapor phases (at checkpoints) for each of the binary pairs of pure components.