Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

A thermodynamic study is carried out on binary systems composed of propyl ethanoate with six alkanes, from pentane to decane. Vapor pressures of the ester and the isobaric vapor liquid equilibria of these six mixtures were measured at 101.32 kPa in a small-capacity ebulliometer and also the mixing properties yE = vE,hE over a range of temperatures and at atmospheric pressure. Adequate correlations are drawn for the surfaces yE = yE(x,T) with an interpretation on the behavior of the mixtures and also using cpE data from literature. The mixing processes are all endothermic with a change in the slope direction of the function hE = hE(T) for the binary systems, which all present expansive effects, with vE greater than 0 and also (?vE/?T)p greater than 0. The results of the different properties are analyzed within a general context of the behavior of ester + alkane systems. A parametric model is used that enables the simultaneous correlation of the experimental values of different thermodynamic properties for each of the systems considered, slightly improving on the representation obtained with the nonrandom two-liquid (NRTL) model. The representation of vapor liquid equilibrium (VLE) and hE properties with the universal functional activity coefficient (UNIFAC) group contribution model is acceptable, although it does not reflect the change in enthalpies with varying temperature, resulting in an unacceptable estimation of cpE.