Mild One-Pot production of glycerol carbonate from CO2 with separation from ionic liquid catalyst

Abstract

Carbon capture and utilization stands as way forward in the minimization of CO₂ emissions. It complements the search for clean and effective energy, as it is challenging to achieve zero to negative CO₂ net emissions. The glycerol carbonate product opens a new strategy based on a double-residue approach (glycerol and CO₂) to contribute, together with ionic liquids (ILs), drafting a new one-pot concept (intensified three phase reactor) at mild conditions and using homogeneous catalysts. In this work, the catalytic activity of [P666,14][Br] in the cycloaddition of CO₂ to glycidol has been demonstrated to be highly effective under mild conditions of 45 °C and 5 bar. In addition, liquid–liquid extraction approach is found to be an efficient separation strategy for carbonate product and IL catalyst. 1-Decanol (DOH) is selected as efficient extracting solvent, due to its almost complete immiscibility with glycerol carbonate, as well as the high distribution ratio of the IL catalyst in DOH rich phase. It implies an easy product separation and, simultaneously, an easy catalyst recovery. A preliminary kinetic validation of the three-phase reactor performance has been properly described, enabling the intensified concept. Finally, combining COSMO/Aspen simulation and life cycle assessment (LCA) methodologies, low energy consumption (avoiding heating) and low GWP scenarios for the CO₂ conversion process have been concluded. This work enables a new concept together with concluding the path to developing this CCU technology in the search of zero to negative CO₂ emissions to sustainably capture and convert CO₂ into value-added products.