Kinetics of acetic acid and isoamyl alcohol liquid esterification over Amberlyst-70

Abstract

This work is a kinetic study on liquid phase esterification between acetic acid and isoamyl alcohol using Amberlyst-70 as catalyst. There are not scientific papers with fitted kinetic models for this esterification system using this catalyst. Experiments were carried out in a laboratory batch reactor at controlled temperature conditions. Molar feed ratio (between 2 and 0.5), temperature (between 353.15 K and 383.15 K) and catalyst load (between 0.5 wt% and 2.0 wt%) were the manipulated experimental conditions. Measured composition profiles were used to fit the parameters for three versions of the pseudohomogeneous model (PHM) that differ in their activity model. At the end, a PHM model based on molar fractions is recommended to explain composition changes due to the esterification reaction. Calculated values for activation energy and chemical equilibrium constant are E = 43 kJ/mol and KE = 5.22, respectively. In accordance with the Weisz-Prater criterion, intraparticle mass transport effects were appreciable in experimental kinetic tests due mainly to the particle size used (0.363 mm). In order to take into account diffusional effects, the effectiveness factor was calculated using the Maxwell-Stephan equations. Therefore, adjusted models are the intrinsic kinetics and they can be used to simulate and design reactors and reactive distillation operations.