Kinetic Model For The Esterification Of Methanol With Acetic Acid In The Presence Of Cation-exchange Resin

Esterification catalyzed by fine particles of ion exchange resin is a good method for the synthesis of methyl acetate by Methanol and Acetic acid. It holds the advantages of high mass and heat transfer rates and a high selection of product. In this paper, the kinetics of esterification catalyzed by fine particles of ion exchange resin was studied. The effect of stir speed and aperture of ion-exchange resin on the conversion ratio was experimentally investigated. The experiment results indicated that when the stir speed was higher than 500r/min, the influence of external diffusion could be eliminated. When the aperture of ion-exchange resin is less than 0.6mm, the influence of internal diffusion could also be eliminated. When the crude catalyst with aperture ranges from 0.6-1.25mm was used, the conversion ratio declined evidently. Methyl acetate was prepared in a batch mode reactor by methanol with acetic acid catalyzed by a macroporous ion-exchange resin, under the conditions that internal and external diffusions could be eliminated. A pseudo-homogeneous phase kinetic model was developed to describe the process and the parameters of the model were gained by fitting the predicted value with the experimental data. The effect of temperature, catalyst loading, mole ratio of reactants on batch reaction rate was taken into account in the kinetic model. The relationship between the reaction rate and temperature was described by the Arrhunius equation and the activation energy of the positive reaction E was 50.31kJ/mol. The reaction rate increased linearly with the catalyst loading in the experimental range. The simulation of esterification by using Aspen Plus cooperated with the kinetic model shows that the calculated results agree well with the experimental data. Furthermore, the suitable reaction conditions were obtained which were helpful for the design of esterification process.