A Study On Applying The Catalytic Distillation Technique To The Hydrolysis Of Methyl Acetate

The purpose of this thesis is to apply the catalytic distillation technique to the hydrolysis of methyl acetate by breaking through the limitation of chemical equilibrium for getting high conversion of hydrolysis. The main works are as follows:1. By comparing and analyzing the solid acidic catalysts for the hydrolysis reaction, and considering the requirement of catalyst loading, cation exchange resin and membrane were selected. The kinetics of the hydrolysis of methyl acetate was measured by using a batch stirred reactor. On the basis of eliminating external and internal diffusional resistances, data of the reaction rates in the wide ranges of temperature, molar ratio and catalyst concentration were obtained.From the fittness of experimental results of initial reaction rates with the Langmuir-Hinshellwood models, a most relevent form of rate expression was selected and the corresponding parameters were obtained. It was found that the heterogeneous model is superior than the homogeneous model.From the calculated reaction rates of cation exchange resin and membrane by using the heterogeneous model, conclusion can be made that the resin is superior than the membrane.2. The hydrolysis of methyl acetate using catalyst packing made by ourselves was studied in a packed type catalytic distillation column. The hydrolysis conversions and the concentration profiles along the column for the different feeding mode, feed flux, feed molar ratio, reflux and its location were determined.On the basis of the film model and the theory of effective mass transfer, the heat and mass transfer processes were analyzed. Wilson equation was used to calculate the vapor-liquid phase equilibrium, in which the influences of association of acetic acid is taken into account. The heterogeneous kinetics model equation was used to calculate the reaction quantities on the surface of the solid catalyst, upon which a general nonequilibrium stage model was obtained. In consideration of the characteristics of the present system, the model was reasonably simplified.By using the effective catalytic surface expressions to calculate the catalyst utilization ratio and the relaxation method to solve the nonequilibrium stage model, it was found that the calculated results of the hydrolysis conversions and the concentration profiles were in good agreement with the experimental values. In addition, the influences of feeding mode, feed molar ratio, feed flux, reflux and the heights of reactive section and separating section on the hydrolysis conversions were calculated systematically, the inherent law of the hydrolysis process of methyl acetate catalytic distillation was known well.