Kinetics of Synthesis and Hydrolysis of Ethyl Benzoate over Amberlyst 39

Abstract

The kinetic behavior of the synthesis and hydrolysis of ethyl benzoate over an acidic cation-exchange resin, Amberlyst 39, was investigated with a fixed-bed reactor at atmospheric pressure. The esterification of benzoic acid with ethanol was implemented at temperatures between 323.15 and 353.15 K under various molar ratios of feed, θB0 (ethanol to benzoic acid). The hydrolysis of ethyl benzoate was also conducted in the same temperature range with a variety of molar ratios of feed, θC0‘ (ethyl benzoate to water) and θB0‘ (ethanol to water). The equilibrium conversion of benzoic acid in the esterification was found to increase with an increase in both temperature and θB0. Additionally, the relative adsorption constants between two reacting species were determined from adsorption experiments. The magnitudes of the adsorption constants follow the order water > ethanol > ethyl benzoate > benzoic acid. The kinetic data of both the synthesis and hydrolysis of ethyl benzoate were simultaneously correlated with the quasi-homogeneous, Eley−Rideal, and Langmuir−Hinshelwood−Hougen−Watson (LHHW) models. The LHHW model yielded the best representation for the kinetic behavior of the liquid−solid catalytic synthesis and hydrolysis of ethyl benzoate.