Continuous production of dimethyl carbonate by reactive distillation process

Abstract

Distillation is the most used separation method. Distillation and reaction generally can be operated independently each other. However, if a reaction will be performed in a distillation column, much higher conversion can be achieved by removing product continuously under the Le Chatelier's principle. Recently, Dimethyl carbonate (DMC) has been appealing to an environmentally benign chemical. DMC is useful to substitute phosgene, methyl chloride, dimethyl sulfate as methylating and carbonylating agent in very versatile reactions. Its production can be applied well to the reactive distillation process. This work focused on the continuous synthesis of DMC by reactive distillation in a pilot-plant scale and the various optimal reaction conditions and properties. The steady-state process simulation was also studied and compared with the experimental results using a commercial modeling. DMC yield more than 99% could be reached by the condition of molar feed ratio of MeOH/EC=9, reaction temperature of 80degreesC, reflux ratio of 11 and pressure 1.8 bar. So far, DMC was produced around 300 g/h using reactive distillation column (diameter: 3 in, high: 5m, 1/4" raschig ring packing).