Study On Synthesis Of DMC Via Transesterification By Slurry Catalytic Distillation Process

Compared with conventional catalytic distillation, slurry catalytic distillation holds more advantages, such as: simpler column structure, easier to be operated and controlled, higher efficiency of reaction and separation, more suitable to large scale production, ect. Catalyst used in this process is fine granule and is mixed with liquid phase to form slurry which flows down in the column and recycles between columns. In this paper, the slurry catalytic distillation process was experimentally studied on the synthesis of dimethyl carbonate. The experiments were carried out in a packed column with an inner diameter of 25mm and the catalyst was strong basic ion-exchange resin about 4μm in diameter.The effects of catalyst concentration, reflux ratio, feed mole ratio of methanol to propylene carbonate and total feed flow on the process were experimentally investigated. The experiment results indicate that: the increase of catalyst concentration, feed mole ratio of methanol to propylene carbonate and the decrease of total feed flow can increase the conversion of propylene carbonate, but when the catalyst concentration and mole ratio of methanol to propylene carbonate were increased to a certain extent, there is no need to increase them any more; along with the rising of reflux ratio the conversion of propylene carbonate began to increase and then decreased, the optimal reflux ratio was between 3 and 5.The process was simulated using Aspen Plus, calculated results agree satisfactorily with experimental data. The profiles of temperature, liquid flow, vapor flow and synthetic rate of dimethyl carbonate along with stages of column were obtained which could not be obtained during the experiment.A total flowsheet of synthesis of dimethyl carbonate was proposed and simulated by Aspen Plus, calculated results were obtained. Products have been purified, and the catalyst has been made use of via efficient circulation. After that process has been magnified, the results are also satisfying.At the end, the application foreground of slurry catalytic distillation on tansesterification industry was discussed. Slurry catalytic distillation is a novel catalytic distillation process developed in recent years, and it is worth researching and developing.