Developing slurry based on immobilized and aqueous [MEACl][EDA] for CO2 capture
Sahar Foorginezhad, Xiaoyan Ji
Abstract
• A new strategy is developed by combining immobilization and cosolvent addition. • The slurry exhibited comparable viscosity to MEA. • CO 2 capture capacity reached 24.93 wt% at 22 ℃ and 1 bar. • Recycling studies showed ∼ 91 % regeneration. The urgent need to mitigate climate change and reduce greenhouse gas emissions has underscored the importance of developing effective CO 2 capture technologies. In this study, a novel strategy was proposed and developed, where adding cosolvent and immobilizing deep eutectic solvent (DES) were combined to enhance the performance from capacity to rate. To this end, [MEACl][EDA] (1:5) was chosen as the DES, H 2 O was used as the cosolvent, and silica was selected as the substrate to immobilize the DES; the effects of the DES immobilization amount and the concentration of the immobilized DES particles in the aqueous system as well as temperature on the viscosity and CO 2 capture performance were investigated systematically. Compared to the aqueous DES, the slurry exhibited higher CO 2 uptake and improved kinetics, comparable viscosity before CO 2 capture, and slightly high viscosity after CO 2 capture, where the best sample (3 wt% of (5 wt% DES@silica) in 40 wt% aqueous DES) showed a capacity of 24.93 wt% at the room temperature (22 ℃) and viscosities of 7.32 and 21.82 mPa·s before and after CO 2 capture. Also, the CO 2 capture rate of the slurry reached 1.4 mol CO 2 /(kg sorbent·min) after 2 min at 22 ℃, which was higher than the aqueous DES without immobilized DES (1.24 mol CO 2 /(kg sorbent·min) under the same condition). The prepared slurries showed high stability (over one month) and high regeneration (∼91 % CO 2 capture recovery after 5 cycles).