Preparation and Performance Analysis of Non-aqueous Absorbents Based on alcohol ether organic compounds for CO2 Capture

MEA aqueous solution is widely utilized as an absorbent in chemical absorption processes. However, it is challenged by many disadvantages, including low regeneration capacity and high energy consumption during regeneration. In this study, new no-aqueous MEA absorbents were prepared using alcohol ether organic solvents, including proprylene glycol monomethyl ether (PGME), ethylene glycol butyl ether (EGBE), poly (ethylene glycol) dimethyl ether (NHD) and diethylene glycol monoethyl Ether (DGME). Then the performance of the absorbents was assessed through a series of experiments and based on the results, a comparison was made between the non-aqueous absorbents to the conventional absorbent (30% (mass) MEA aqueous solution). It was found that the organic solvent system presented a higher CO 2 removal efficiency than the MEA-H 2 O system in the first 350 s, with the maximum enhancement ranging from 5.16% to 14.36%. While NHD improved the CO 2 loading but reduced the regeneration efficiency. Except for the MEA-NHD system, all the other no-aqueous absorbents possessed a better regeneration efficiency than the MEA aqueous solution, which offers them the potential for industrial application. According to the data from NMR and FTIR analysis, after CO 2 absorption, the products in the MEA-EGBE and MEA-DGME systems were mainly found in the lower phase, the other phase was mainly organic solvents. Therefore, only the lower phase needs to be treated during desorption, with the upper phase being recycled directly, thus reducing energy consumption. The use of alcohol ether organic solvents can improve the CO 2 capture performance of absorbents to a certain extent and enhance their regeneration ability, providing a new direction for the subsequent research of non-aqueous absorbents.