Thermodynamic prediction of the solvent effect on a transesterification reaction

Abstract

This work focuses on the thermodynamic prediction of solvent effects on the transesterification of butyl acetate with ethanol to butanol and ethyl acetate in the solvent heptane at 293.15 K and 303.15 K. Both, the reaction equilibrium and the reaction kinetics have been investigated experimentally by Schmidt et al. (1999). They found that the solvent heptane does not affect the reaction equilibrium but significantly influences the reaction kinetics. They described the solvent effect on the reaction kinetics by empirically correlating the experimentally-observed apparent rate constants with the dielectric constants of the different reaction mixtures.In this work we re-evaluated the experimental data and now present a thermodynamic approach to consistently predict the solvent effect on both, the reaction equilibrium and the reaction kinetics. Accounting for the activity coefficients of the reactants/products obtained from the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) allowed for considering the interactions of the reactants/products among themselves and also with the solvent heptane. Accounting for those, it is shown that the solvent effect on the reaction equilibrium as well as on the reaction rate can even be predicted in very good agreement with the experimental data.