Integrated Approach to CO₂ Capture and Conversion to Cyclic Carbonates under Solvent- and Additive-Free Conditions Utilizing the CO₂ Capture Solvent EEMPA

An integrated CO2 capture and conversion to materials (IC3 M) implementation utilizing a CO2 capture solvent is an efficient approach to reduce the amount of CO2 in the atmosphere while producing value-added chemicals. Herein, we demonstrate that the advanced water-lean CO2 capture solvent, N-(2-Ethoxyethyl)-3-morpholinopropan-1-amine (EEMPA), can catalyze the cycloaddition reaction between CO2 and propylene oxide to produce the value-added chemical propylene carbonate in an IC3 M fashion. When excess propylene oxide is used relative to EEMPA, yields as high as 75% with 85% selectivity toward propylene carbonate can be achieved under solvent-free conditions without the need of additives/cocatalysts. The reaction temperature (120 °C) is comparable to that used in the thermal regeneration of the capture solvent under industrial conditions. Formation of an undesired amino alcohol side product was observed, but it may be reversible or avoidable with continued research despite the unsuccessful initial attempts. Lastly, we show that this can be applied to other epoxides for the production of various cyclic carbonates.