Comparative kinetics of esterification of methanol-acetic acid in the presence of liquid and solid catalysts

Abstract

Esterification of acetic acid with methanol to produce methyl acetate in an isothermal stirred batch reactor has been studied. Sulfuric acid was used as a liquid catalyst, and Indion-180, Indion-190 and Amberlyst-16wet ion exchange resins were used as solid catalysts. The feed mole ratio was varied from 1 : 1 to 1 : 4. The reaction temperatures were varied from 305.15 to 333.15 K for sulfuric acid as catalyst and 323.15 to 353.15 K for the solid catalysts. The catalyst concentrations were used in the range of 1% to 5%, for the sulfuric acid catalyst, and 0.01 to 0.05 g/cc, for the solid catalysts. The effect of temperature, catalyst concentration, agitation speed, size of catalyst particle and reactant concentration on the acetic acid conversion was investigated. A second-order kinetic rate equation was proposed to fit the experimental data. For both forward and backward reactions, the activation energies were estimated from Arrhenius plots. The reaction rate increased with catalyst concentration and temperature for both the liquid and solid catalysts. The acetic acid conversion was found to increase with increases in acetic acid to methanol ratio in the feed. The developed kinetic rate equation was used for the simulation of reactive distillation process, in our laboratory column. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.