Solvents with Low Critical Solution Temperature for CO2 Capture

The absorption and desorption characteristics of five amine solutions with low critical solution temperature were tested, analyzed and compared with 5 M MEA using a fast screening experiment system. The results showed that among these solvents, 5 M N-Ethylmethallylamine (EMAA) has the fastest initial absorption rate, 3 M Triethylamine (TEA) has the largest carrying capacity, and 2 M Diisopropylamine (DIPA) has the highest CO2 removal efficiency with relatively high absorption rate. 2 M DIPA shows the best performance based on the combined analysis. None of these five amines show phase transition during absorption at 40 °C, while 3 M TEA and 5 M Diallylamine (DAA) become two phases after desorption, and can keep being two phase after cooling to room temperature.