Highly Efficient Absorption of CO₂ by Protic Ionic Liquids-Amine Blends at High Temperatures

High Resolution Image Download MS PowerPoint Slide In view of the increasingly serious harm of CO 2 to the environment, it is highly desirable to develop effective CO 2 absorbents. In this work, we demonstrated an efficient absorption of CO 2 by blends of protic ionic liquids (PILs) plus amines. The density and viscosity of investigative four PILs-amine mixtures were measured. By systematically studying the effects of the solution ratio, temperature, CO 2 partial pressure, and water content on the absorption of CO 2, it is found that the 3-dimethylamino-1-propylamine acetate ([DMAPAH][OAc]) plus ethanediamine (EDA) mixture shows the highest CO 2 uptake of 0.295 g CO 2 per g absorbent at 50 °C and 1 bar and a further increase in the absorption of CO 2 to 0.299 g/g by adding water with a mass fraction of 20%. Furthermore, the absorption mechanism of CO 2 in the presence and absence of water has also been investigated by FTIR and NMR spectra.