Excess properties and isobaric vapor-liquid equilibria for binary mixtures of methyl esters plus tert-butanol

Abstract

This article presents the experimental values obtained for excess properties H-m(E) and V-m(E) at two temperatures and vapor-liquid equilibria at 101.32 kPa for a group of four binary mixtures composed of four methyl alkanoates (methanoate to butanoate) with tert-butyl alcohol. The application of a point-to-point test to the equilibria data showed that the systems studied were consistent. The binary mixture methyl propanoate + tert-butyl alcohol presents an azeotrope at x(az) = 0.726 and T = 350.43 K. All data were correlated by using a new equation with temperature-dependent coefficients by adjusting the quantities of VLE and the H-m(E) simultaneously and modifying for each case the number of adjustable parameters. A good correlation was obtained for all mixtures. Application of the UNIFAC model to mixtures with tert-butyl alcohol produced inaccurate predictions with the version of Hansen et al. and acceptable estimates with the version of Gmehling et al. None of the models gave good estimates of the VLE of the methyl methanoate + tert-butyl alcohol mixture.