Superwetting membrane-based strategy for highly efficient separation of dimethyl carbonate and methanol

Abstract

Dimethyl carbonate (DMC) produced through transesterification, which involves the reaction of methanol (MeOH) with a suitable ester, has been considered as an attractive route for industrial production. Although high-purity DMC can be obtained from DMC/MeOH mixture by energy-intensive extractive distillation or time-consuming pervaporation (PV), it is still challenging to produce pure DMC in an energy-saving and high-efficiency manner. Here we demonstrate an energy-economy yet efficient superwetting membrane (SWM)-based strategy to produce pure DMC by combining porous polytetrafluoroethylene (PTFE) as the solid membrane and eco-friendly water molecules as the liquid inductive agent. The relatively low polar DMC can rapidly and selectively permeate the nonpolar PTFE membrane by nonpolar interaction between PTFE and DMC. Meanwhile, the high polar water molecules generate strong hydration with MeOH, which makes the relatively high polar MeOH/H2O being blocked by the nonpolar PTFE membrane. The SWM system exhibits outstanding separation flux of 1090 L m−2 h−1, with DMC purity higher than 93 wt%. Furthermore, taking advantage of the easy assembly of this SWM with conventional PV, we can produce DMC with purity of 99.4 wt%, showing great potential in practical DMC production.