Isobaric vapor-liquid equilibria and excess quantities for binary mixtures of an ethyl ester + tert-butanol and a new approach to VLE data processing

Abstract

This paper presents the experimental excess properties HmE and VmE obtained at different temperatures and the vapor-liquid equilibrium values at 101.32 kPa for four binary mixtures composed of four ethyl esters (methanoate to butanoate) and tert-butyl alcohol. A point-to-point test applied to the equilibrium values indicated that the systems studied were consistent. The binary mixture ethyl ethanoate + tert-butyl alcohol exhibits an azeotropic point at xaz = 0.832 and T = 349.59 K. All values were correlated using a new equation with temperature-dependent coefficients fitting simultaneously the vapor-liquid equilibria and HmE values. Good fits were obtained in all cases. Application of a modified version of the UNIFAC model to the mixtures containing a tertiary alkanol yielded rather poor estimates.