Kinetic Study of Catalytic Hydrolysis Reaction of Methyl Acetate to Acetic Acid and Methanol

The reaction kinetics and chemical equilibrium of the reversible catalytic hydrolysis reaction of a methyl acetate to acetic acid and methanol using a strongly acidic ion exchange resin catalyst named Amberlyst 15 were studied. To investigate the different behavior of Amberlyst 15 in the adsorption of reactants and product species, the equilibrium behavior of binary non-reactive liquid mixtures, consisting of one reactant and one product were studied experimentally. The Langmuir model was used to describe the equilibrium condition, quantitatively. Then the employed model was compared with the more complicated thermodynamic models to describe the equilibrium between the catalytic polymer resin and the liquid phase. The results indicated a good agreement. The effects of temperature, catalyst weight, and feed molar ratios on reaction kinetics were investigated. Results revealed that the reaction rate was strongly temperature dependent. The chemical equilibrium compositions were measured in a wide range of temperatures and feed molar ratios. Finally, pseudo homogeneous and LHHW (Langmuir Hinshelwood Hougen Watson) models were developed to calculate the rate of the reaction. Optimization of the model s parameters indicated that the use of activity instead of mole fraction, and also the use of LHHW rather than a pseudo homogeneous model resulted in much smaller residual errors. Also the equilibrium compositions obtained from the equation of rates were in good agreement with the experimental results.