Multiproperty modeling for a set of binary systems. Evaluation of a model to correlate simultaneously several mixing properties of methyl ethanoate + alkanes and new experimental data

Abstract

This work makes a theoretical–experimental contribution to the study of ester and alkane solutions. Experimental data of isobaric vapor–liquid equilibria (VLE) are presented at 101.3kPa for binary systems of methyl ethanoate with six alkanes (from C5 to C10), and of volumes and mixing enthalpies, vE and hE. An interpretation of the behavior and a verification of structural models proposed previously by the same group are also given. For the treatment of thermodynamic data a polynomial model is proposed to obtain a simultaneous correlation of different properties available for a same system. Liquid–liquid equilibrium (LLE) data at low pressure are also used and cpE values, taken from literature, to perform the correlations described, generating a working procedure which is started on LLE data. The properties used for correlating are obtained in very different working conditions making it difficult to obtain a single correlation. However, the procedure followed produces good multiproperty correlations for each of the systems. An extended version of the NRTL model is also used with the purpose of comparing the efficacy of the method and model proposed, and produces acceptable results for the isobaric and isothermal VLE equilibrium but not for the LLE. Specifically, the model does not take into account the variation in hE=φ(T), as it does not reproduce the cpE. Estimates of the same properties made with the UNIFAC group contribution method are comparable to those obtained with the correlative NRTL method.