Thermodynamic and molecular insights into CO 2 absorption using linear carboxylic esters

Linear carboxylic esters are promising physical solvents for efficient CO 2 absorption. In order to examine their potential application in CO 2 capture under high CO 2 partial pressure, we measured the vapor–liquid equilibrium (VLE) data of CO 2  + different carboxylic esters under low temperatures and high pressures, and the obtained VLE data were well correlated using PR, SRK, and PC‐SAFT equations. Thermodynamic analysis, quantum chemical calculation, and molecular dynamics simulation were carried out to provide the thermodynamic and molecular insights into the mechanisms of CO 2 absorption, and the effects of the esters' molecular structure on their CO 2 absorption performance. It is found that the carbon‐chain length of the alkyl groups, especially for those connected with the oxygen atom in ester groups, has significant effects on CO 2 absorption capability. Moreover, the methyl acetate with the shorter carbon‐chain length shows the highest CO 2 solubility, indicating it as a potential candidate toward efficient CO 2 capture.