(586e) Intensified Process Design Alternatives for the Diethyl and Ethyl-Methyl Carbonate Production

Reactive distillation allows enhancing selectivity in multi-reaction equilibrium systems, where more than one component is valuable. The production of diethyl carbonate (DEC) is particularly attractive for its wide usage as a fuel additive and lithium battery applications. It can be produced by transesterification of dimethyl carbonate (DMC), which consists of two reactions, having ethyl methyl carbonate (EMC) as a valuable reaction intermediate. This work aims to present three different reactive distillation systems (RC), one to favour the production of DEC, another for the production of EMC, and one to produce both compounds simultaneously (DEC-EMC). Such processes were optimized considering the total annual cost (TAC) to compare them, which includes capital and operating plant costs. Also, a techno-economic analysis was carried out considering the TAC, the price of the products, and the raw materials costs. The distillation columns were designed and simulated in the process simulator Aspen Plus and optimized through Python via particle swarm optimization (PSO) technique. Product purities of 0.99 and 0.98-mole fraction for the DEC and EMC were considered, respectively.

The results showed that producing only EMC provides 50% more utilities compared to the column that produces only DEC, even though the TAC of the EMC design is 36% higher than the DEC design. The TAC of the column that generates both components provides 47% more utilities over the DEC production process. Therefore, the design that showed the best economic performance was the EMC production process, considering the current product market costs.