Optimization of a Reactive Distillation Process for the Synthesis of Dialkyl Carbonate Considering Side Reactions

Dimethyl carbonate (DMC) is an environment-friendly chemical, widely used as a solvent, reagent, and fuel additive. It is produced commercially via transesterification, an equilibrium reaction in which ethylene carbonate (EC) and methanol (MeOH) react to produce DMC and a useful coproduct, monoethylene glycol (MEG). However, side reactions occur, such as the reaction of EC with MEG to produce diethylene glycol and CO₂. These reactions must be considered to simulate the DMC process accurately. Reported theoretical results without considering the side reactions differed by 1.7% from industrial results. Here, side reactions were considered to improve the simulation accuracy; a relative error of only 0.1% was obtained. The optimal EC:MeOH feed ratio was changed (from 8.1 to 8.5) to increase the profit to 0.2 USD per kmol of EC. Thus, herein we show how to increase the profit by process modification, which will be useful for studies involving commercial plant simulation.