Thermodynamic Properties of Systems Comprising Esters: Experimental Data and Modeling with PC-SAFT and SAFT-γ Mie

Abstract

In this work, new experimental vapor-pressure data of 14 esters were obtained using the transpiration method. Besides dimethyl fumarate, dimethyl maleate, diethyl maleate, benzyl ethanoate, benzyl propanoate, and benzyl butanoate, eight representatives of the homologous series of ethyl alkanoates were investigated. The pure-component vapor pressures and liquid densities were modeled by means of Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) and SAFT-γ Mie. Satisfying modeling results could be achieved with both equations of state. Furthermore, the molar excess enthalpies of 12 binary mixtures benzyl ethanoate + n-alkane were modeled. Only one binary interaction parameter was fitted for PC-SAFT to quantitatively predict the molar excess enthalpies of all binary mixtures under study, while SAFT-γ Mie predicts these properties in qualitative agreement with the experimental data. Finally, the liquid–liquid equilibria of three binary mixtures ester (benzyl ethanoate, dimethyl maleate, and diethyl maleate) + water were investigated. These systems show a very low and almost temperature-independent solubility of the ester in the aqueous phase, whereas the moderate solubility of water in the organic phase is temperature-dependent. Promisingly, both PC-SAFT and SAFT-γ Mie predicted broad and unsymmetrical miscibility gaps for these mixtures, which is in qualitative agreement with the experimental data.