Efficient CO2 capture using deep eutectic solvent-activated carbon slurry systems

The need for effective CO 2 mitigation has led to research into capture technologies using novel solvents, such as deep eutectic solvents (DES), which are known for their high CO 2 capture capacity. However, their high viscosity and cost are the main challenges. In this study, we aimed to enhance the CO 2 capture capacity of monoethanolamine chloride: ethylene diamine ([MEACl][EDA]) with (1:5) molar ratio, while addressing these limitations by developing a slurry. Water was added as cosolvent, and activated carbon was considered as the substrate for DES immobilization. The resulting slurry system demonstrated enhanced CO 2 uptake and improved kinetics, with a viscosity within the same range as that of the aqueous DES. Upon capture, only a slight increase in viscosity was observed, maintaining comparable performance to the aqueous system. The optimal slurry demonstrated a CO 2 capture capacity of 26.12 wt% at 22 ℃, with viscosities of 8.14 and 22.82 mPa·s before and after CO 2 capture, respectively. The CO 2 capture rate of the slurry reached 1.67 mol CO 2 /(kg sorbent·min) within the first 2 min at 22 ℃, surpassing the rate of the aqueous DES (1.24 mol CO 2 /(kg sorbent·min)). Furthermore, the prepared slurry maintained ∼90 % of CO 2 uptake after five regeneration cycles and depicted almost the same performance after one month. • The slurry made by AC exhibited high CO 2 uptake (26.12 wt%). • The viscosity of the slurry was 8.14 and 22.82 mPa·s before and after CO 2 capture. • CO 2 capture performance was preserved up to one month of operation. • ∼90 % regeneration efficiency was obtained over five sorption-desorption cycles.