Generalized binary interaction parameters in the Wong-Sandler mixing rules for mixtures containing n-alkanols and carbon dioxide

Generalized correlations for mixing rule interaction parameters as functions of the reduced temperature and a polar parameter in n-alkanol + carbon dioxide mixtures, were obtained. Ten mixtures containing sub and supercritical carbon dioxide and one n-alkanol (from methanol to decanol) were considered in the study. The Peng-Robinson equation of state has been used and the Wong-Sandler mixing rules, that include a model for the excess Gibbs free energy gE, have been incorporated into the equation of state constants. In the Wong-Sandler mixing rules the van Laar model for gE has been used. The experimental data were obtained from literature sources and the adjustable parameters were found by minimizing the errors between predicted and experimental data of pressure and solute concentration in the gas phase. It is shown that the proposed generalized correlations have predictive capabilities with accuracy similar to the best correlating tools available in the literature.