(119c) Process Intensification for Diethyl Carbonate Production By Combining Reaction and Separation

In this study, we propose an improved process for the production of diethyl carbonate from ethylene carbonate and ethanol through transesterification reactions in a reactive distillation process, aiming to enhance energy efficiency and economic feasibility. The feedstock for diethyl carbonate production, dimethyl carbonate, has been challenging to separate due to the formation of a low-boiling-point azeotrope with methanol. Special distillation techniques such as pressure swing distillation or extractive distillation have been required for its separation. To address this issue, our study integrates the production processes of dimethyl carbonate and diethyl carbonate using only reactive distillation, eliminating the need for separating the azeotrope. Two design alternatives are proposed depending on configuration of reactive distillation. The first alternative utilizes two reactive distillation columns, allowing the direct transfer of the product from the first column to the second without separating the azeotrope. This reduces the overall number of required equipment and results in a 12% reduction in total utility consumption and total annual cost compared to the existing process. The second alternative conducts all transesterification reactions in a single reactive distillation column, achieving a 24% reduction in total utility consumption and a 14% reduction in total annual cost. These newly proposed processes not only enhance economic feasibility but also reduce carbon dioxide emissions by 15% and 11%, respectively.