Liquid–Solid Phase-Change Behavior of Diethylenetriamine in Nonaqueous Systems for Carbon Dioxide Absorption

Conventional amine scrubbing systems for carbon dioxide capture require a large amount of energy to regenerate the absorbent. Theoretically, if CO 2 -captured product can be separated from the liquid counterpart, and only this product need to be heated for desorption, the energy efficiency for CO 2 capture can be improved greatly. In the present work, diethylenetriamine (DETA) dissolved in ethanol, diethylene glycol dimethyl ether, N -methyl-pyrrolidone, or dimethyl carbonate can absorb CO 2 to result in liquid–solid phase-change in addition to making the reaction to achieve its stoichiometric maximum. The results show that the different organic solvents have no influence on the formation of precipitate. Single-crystal structure analysis indicates a DETA–carbamate is formed with equimolar CO 2 absorption. The absorption–desorption cycles using microwave heating shows that the system has a relatively stable cycling performance.