Deep eutectic solvent-based slurry for CO2 capture: Enhanced efficiency and kinetics

Abstract

The imperative need to mitigate CO₂ emissions has become increasingly critical due to their severe impact on environmental sustainability and public health. Among the emerging carbon capture technologies, deep eutectic solvent (DES)-based technologies have attracted significant attention owing to their facile synthesis and superior CO₂ capture capacity. However, their widespread industrial deployment has been hindered by challenges associated with high viscosity and cost. To address these limitations, this study adopts novel a approach that synergistically integrates cosolvent addition and immobilization to develop a slurry with enhanced CO₂ capture efficiency. Specifically, an aqueous DES solution was formulated using imidazolium chloride-ethylenediamine ([ImCl][EDA]) in a 1:6 molar ratio with water as the cosolvent, followed by the immobilization of DES onto mesoporous silica to form a composite slurry. CO₂ capture experiments revealed a high sorption capacity of 28.34 wt% at 22 °C and 1 bar, along with rapid sorption and desorption rates of 1.39 and 0.30 mol CO₂/(kg sorbent·min) within the first 2 min. Furthermore, the slurry exhibited excellent cyclic stability, maintaining a 98 % recovery rate. The significant improvements in CO₂ capture capacity, desorption kinetics, and thermal stability underscore the potential of this hybrid system for scalable industrial applications in carbon capture and utilization.