Breaking azeotropes by reactive adsorption: A case for sorption-enhanced dimethyl carbonate synthesis

This work investigates the direct production of dimethyl carbonate (DMC) from CO₂ by sorption-enhanced DMC (SEDMC) synthesis, employing modelling techniques. SEDMC synthesis is shown to be an exemplary case for reactive separation, as it enhances the reaction and simplifies downstream processing through in-situ separation. By incorporating in-situ water adsorption, SEDMC achieves significantly higher methanol conversions compared to other direct synthesis routes. Simultaneously, the formation of two azeotropes can be avoided, leading to a drastic simplification of downstream separation, requiring only one-step conventional distillation. By increasing the methanol conversion to 45%, the formation of a DMC-methanol azeotrope is prevented, and the in-situ water adsorption effectively avoids the DMC-water azeotrope. Based on these findings, further research should focus on identifying suitable materials and (reactive) adsorbents, while also incorporating a more detailed process layout and cycle design. These efforts will unlock the full potential of SEDMC synthesis in the production of renewable materials.