Kinetic Study of the Heterogeneous Catalytic Esterification of Acetic Acid with Methanol Using Amberlyst®15

The synthesis of methyl acetate via esterification of acetic acid with methanol is a prominent example of equilibrium-limited esterification reactions with low reaction rates in the absence of catalysts. The acidic ion-exchange resin Amberlyst 15 is a potential heterogeneous catalyst. The aim of this study was to investigate the reaction kinetics of the heterogeneous catalytic esterification of acetic acid and methanol with Amberlyst 15, including the adsorption behaviour and heats of adsorption of the reactants on the ion-exchange resin. The reaction kinetics was modelled based on the Langmuir-Hinshelwood-Hougen-Watson approach. Independent adsorption experiments with non-reactive binary mixtures were performed and incorporated into the kinetic model. The heats of adsorption of the reactants were determined in order to account for the temperature dependency of the heterogeneous catalytic reaction. From the enthalpy of adsorption, physical interaction of all constituents with the catalyst was concluded. The Langmuir-Hinshelwood-Hougen-Watson model showed good agreement with the experimental results.