Predicting the Solvent Effect on Esterification Kinetics.

It is well known that solvents influence reaction kinetics. The classical concentration-based kinetic modeling is unable to describe these effects. In this work, the reaction kinetics was studied for the esterifications of acetic acid and propionic acid with ethanol at 303.15 K. It was found that the reactant ratio as well as the applied solvents (acetonitrile, tetrahydrofurane, dimethylformamide) significantly affect the reaction rate. The thermodynamic model PC-SAFT was applied to account for the interactions between the reacting species and the solvents via activity coefficients. This allowed the identification of solvent-independent kinetic constants and the prediction of the solvent effect on reaction kinetics in almost quantitative agreement with experimental data. The presented approach shows the importance of taking into account thermodynamic non-idealities and significantly reduces experimental effort for finding the best solvent candidate for a given target reaction.