Reaction-extraction platforms towards CO2-derived cyclic carbonates catalyzed by ionic liquids

Abstract

This work systematically monitors the keys to understand the applicability of two close-cycle processes recently proposed that enable the regeneration of homogeneous catalysts based on ionic liquids by liquid-liquid extraction. It aims at looking for more efficient CO2 conversion platforms to prevent global warming. The universal character of these two platforms is here demonstrated for a substrate scope that accounts the 7 most representative cyclic carbonates of the literature and 17 ionic liquids that play the role of efficient homogeneous catalysts. Water-based platform proves to be more appropriate for separating hydrophilic IL catalysts from less polar and hydrophobic carbonates, improving the energy consumption when compared with distillation as benchmark separation approach in the literature. On the contrary, hydrophobic ionic liquids enhance the process combined with fatty alcohols to produce hydrophilic cyclic carbonates and drastically reduce energy consumption at reasonable lower product specifications when compared with benchmark process. Overall, liquid-liquid extraction stands out as a more efficient process scheme to separate cyclic carbonates from homogeneous catalysts based on ionic liquids.