Utilization of CO2 in Micropacked Bed Reactors for Enhanced Synthesis of Cyclic Carbonates

Abstract

Conversion of carbon dioxide (CO₂) to cyclic carbonates is important for carbon capture and utilization and enables the production of valuable, non-toxic chemicals from a climate-relevant greenhouse gas. This paper reports a catalytic strategy for synthesizing cyclic carbonates using commercial solid mesoporous silica supports with controlled particle sizes. Tripropylammonium groups were grafted onto the silica surface to activate it for CO₂ conversion. Batch reactor experiments confirmed that the functionalized silica catalyzes the reaction under milder temperature and pressure conditions than previously reported. A subsequent gas-phase cycloaddition reaction was conducted in a micropacked bed reactor. The reactor performance was assessed using the chemical regime method to separate intrinsic kinetics from mass transfer effects. Compared to conventional fixed-bed reactors, the reaction times were significantly reduced, from several days in batch systems to ~1 minute in centimetric reactors and <1 second in microreactors. These findings support the potential for commercial-scale implementation.