Kinetics of heterogeneously MgO-catalyzed transesterification

The transesterification of ethyl acetate with methanol over magnesium oxide as solid base catalyst was investigated. Intrinsic kinetic data have been obtained in a perfectly mixed slurry batch reactor. The influence of the temperature (283–323 K) and the initial methanol to ethyl acetate molar ratio (M/E: from 0.1 to 10) was investigated over a broad ethyl acetate conversion range (1–95%). A kinetic model was developed based on a three-step ‘Eley–Rideal’ type of mechanism applied in liquid phase, describing the experimental data over the investigated range of experimental conditions. Transesterification reaction occurs between methanol adsorbed on a magnesium oxide free basic site and ethyl acetate from the liquid phase. Methanol adsorption is assumed to be rate-determining. Other models derived from other mechanisms were rejected based on statistical analysis, mechanistic considerations and physicochemical interpretation of the parameters. The calculation of activity coefficients accounting for non-ideality had to be incorporated in the parameter estimation procedure.