Highly Efficient Absorption of CO(2) by Protic Ionic Liquids-Amine Blends at High Temperatures

[Image: see text] 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.