Isobaric Vapor–Liquid Equilibrium for the Binary Systems Dimethyl Disulfide + C1–C4 n-Alkanol at 40.000 and 101.325 kPa

Abstract

The vapor–liquid equilibrium (VLE) data for the binary mixtures dimethyl disulfide + methanol, dimethyl disulfide + ethanol, dimethyl disulfide + 1-propanol, and dimethyl disulfide + 1-butanol have been measured over the complete composition range at p = 40 and 101.325 kPa using a Fischer Labodest ebulliometer. All of the considered binary systems exhibit azeotropic points. The study of the effect of pressure upon the azeotropic composition shows that an increase in the number of carbons in the n-alkanol induces the composition of the azeotropic point to move toward the dimethyl disulfide-rich region. Our experimental data were correlated by the Wilson equation and checked for thermodynamic consistency. The reduced excess Gibbs function was also calculated, and the values of this property are discussed in terms of molecular interactions. Moreover, our experimental VLE data were compared with those calculated with the modified UNIFAC model with unsatisfactory results.