Critical comparison of the methods combining the equation of state and excess gibes free energy models for the predicting vapour-liquid equilibria

A critical analysis of the accuracy of the methods which predict vapour-liq uid equilibria at elevated pressures. Four methods combining equations of s tate (EOS) and excess Gibbs free energy models are considered and their acc uracies are compared with the precision of Soave-Redlich-Kwong (SRK) EOS us ing binary interaction coefficients k(ij) in the mixing rule. The analysis has defined the systems for which these four methods considerably improve t he accuracy of the thermodynamic description as well as the mixtures for wh ich the simple model SRK is more precise.