Solubility of CO2 in Nonaqueous Absorption System of 2-(2-Aminoethylamine)ethanol + Benzyl Alcohol

A mixture of 2-(2-aminoethylamine)ethanol (AEEA) with benzyl alcohol (BP) as absorbent was developed to reduce energy consumption in an amine-based CO 2 capture process. The solubility of CO 2 in the AEEA + BP solution was compared with AEEA + diethylene glycol (DEG), AEEA + triethylene glycol (TEG), and AEEA + H 2 O. The CO 2 loading (mol CO 2 /kg amine) at the same CO 2 partial pressure was in the order AEEA + H 2 O > AEEA + BP > AEEA + TEG > AEEA + DEG, and CO 2 loading of all these solutions increased with increasing vapor pressure of CO 2 . Besides, the CO 2 loading in AEEA + BP solution significantly decreased with increasing reaction temperature. The desorption rate of AEEA + BP solution was about 1.3 times faster than that of aqueous AEEA solution at the same desorption temperature, and AEEA + BP solution needed 30% time less than AEEA + H 2 O solution to reach reaction end point. The AEEA + BP solution showed stable repeatability in four cycles of absorption–desorption tests.