Heterogeneous Kinetic Study for Esterification of Acetic Acid with Ethanol

Abstract

The esterification of acetic acid with ethanol has been investigated in the presence of a low cost ion exchange resin mainly used in the water treatment industry namely Trilite SCR-B as a heterogeneous catalyst. Internal mass transfer limitations have proven to be negligible using analysis based on Thieles modulus. The results of the experimental runs done by varying stirrer speeds of the reactor showed the absence of external mass transfer limitations. The kinetic experimental results were correlated with the heterogeneous kinetic models Langmuir-Hinshelwood (LH), Eley-Rideal (ER) and pseudo homogeneous kinetic model. The LH model was found to be correlating the experimental results better than the other two models. Reaction and adsorption constants were further evaluated within the temperature range between 335K and 355K, with 1:1 ethanol to acetic moles ratio under a catalyst loading of 50g/L. The study results of adsorption of both water and ethanol on to the cation exchange resin surface were found to be exothermic under the tested conditions. Furthermore, effect of concentration of each reactant on the reaction rate was examined using initial reaction rate measurements.