No abstract

In the present study, the kinetics of esterification of acetic acid with isobutanol was studied by using Amberlite IR-122 as an acid catalyst. Experiments were carried out in a stirred batch reactor in dioxane at different temperatures (323 to 348 K) under atmospheric pressure. The equilibrium constant was found to be constant as 4 in the temperatures ranging from 323 to 367 K. The possible mechanism of reaction was mathematically treated using the theories of the Eley-Rideal model based on inhibition by water and isobutanol on the resins. The reaction rate constants and the adsorption coefficients for isobutanol and water were determined from the experimental data at the same temperature intervals. Furthermore, the activation energy of the esterification reaction was found to be 50.5 kJ=mol. The heat of adsorption for isobutanol and water was also calculated as À50.9 kJ=mol and À18.9 kJ=mol, respectively.

Kinetics of heterogeneous catalysed esterification of propionic acid with n-amyl alcohol was studied with a microporous cation-exchange resin catalyst, Dowex 50Wx4, in a stirred batch reactor to synthesise amyl propionate. Effects of various parameters such as speed of agitation, catalyst loading, and reaction temperature on reaction rate were investigated. The equilibrium conversion of propionic acid increased with in catalyst loading and reaction temperature. Stirrer speed had virtually no effect on the reaction rate under the experimental conditions. The apparent activation energy was found to be 43.167 kJmol−1 for the formation of amyl propionate and the equilibrium constant, which is independent of temperature ranging from 318 to 348 K, was found to be 4.05. It was also observed that the initial reaction rate decreased with water concentrations and increased with that of acid and increased with that of alcohol linearly. The reaction was found to occur between an adsorbed acid molecule and a molecule of alcohol in the bulk and it was concluded that the reaction mechanism can be represented by Eley-Rideal model.