(372u) Eutectic Ionic Liquids for Efficient Gas Separation | AIChE

(372u) Eutectic Ionic Liquids for Efficient Gas Separation

Absorption of gases such as CO, CO2 and SO2 are highly important, because these gases threaten environment and people’s health. Thus, new absorbent materials that can efficiently, reversibly, and economically capture CO, CO2 and SO2 must be developed. Eutectic ionic liquids (EILs) are considered as the alternative absorbents for gas capture due to the unique properties of ionic liquids. Compared with the conventional ILs, EILs are more attractive in CO, CO2 and SO2 absorption in recent years.

In this work, a series of functionalized EILs with multi-site anions were developed for efficient and reversible CO, CO2 and SO2 absorption through cooperative interaction. These functionalized EILs contain nitrogen and oxygen atoms as active multi-sites in their anions. It was found that EILs with Cu(I), imide anions and pyridinolate anions are efficient for CO, CO2 and SO2 capture under low-concentration, respectively. To study the selectivity of SO2/CO2, the SO2 absorption and CO2 absorption were performed using EIL-based task-specific deep eutectic solvents. Thus, high absorption capacities, rapid absorption kinetics, and low absorption enthalpies could be obtained through preorganization and cooperation strategy. The absorption mechanisms were investigated by using IR, NMR, and DFT calculation. This new process using multi-site anion-functionalized EILs is also applicable to the capture of other gases such as CO and NO. This work was supported by the Natural Science Foundation of China (No. 22078294).

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