Novel pervaporation-assisted pressure swing reactive distillation process for intensified synthesis of dimethyl carbonate

Abstract

Dimethyl carbonate (DMC) is an environmentally friendly agent with low toxicity and fast biodegradability. DMC synthesis by transesterification of propylene carbonate with methanol has been developed as a cost-efficient option. However, even reactive distillation combined with a series of distillation columns requires significant energy and capital cost. To solve these problems, a novel pervaporation-assisted pressure swing reactive distillation process is proposed in this work as an eco-efficient solution for the transesterification synthesis route.Rigorous simulations were carried out in Aspen Plus, using a custom pervaporation model developed in Aspen Custom Modeler (ACM). Pervaporation (PV) is used for the efficient separation of DMC/MeOH azeotrope, and employs polydimethylsiloxane / polyvinylidene fluoride (PDMS/PVDF) composite membrane. The membrane area is optimized to minimize total annual cost (TAC) of the process. Energy integration by Pinch Analysis was also carried out using Aspen Energy Analyzer to determine the optimal heat exchangers network.The results show that the new intensified PSRD-PV process is more competitive compared with the reference reactive distillation (RD) process reported in literature, allowing about 32 % energy savings (due to the ability of PV to separate an azeotrope without distillation), around 42 % lower annual cost (1.72 M$ yr−1), as well as largely improved sustainability metrics.