Properties of aqueous amine based protic ionic liquids and its application for CO2 quick capture

Three kind of pure amines which have high solubility of CO2 were used as absorbents hardly to be recovered. A series of aqueous ethoxyacetate anion-based protic ionic liquids (PILs) with three different amine cations were designed, and physical properties including measured density and viscosity were measured. Solubility of CO2 in the three PILs solution, 90% [DMAPAH][EOAc], 90% [DEEDAH][EOAc] and 90% [DMEDAH][EOAc], were systematic determined at the range of 303.2-333.2 K under the pressure of 1.2 bar. Impressively, the solubility of CO2 in 90% [DMAPAH][EOAc] reached up to 2.44 mol/kg, which showed more advantage than some traditional or functional ILs. The 90% [DMAPAH][EOAc] could be reused four times. Besides, the proposed mechanism was advised. Considering the advantages of high absorption capacity, low cost, easy regeneration including fast absorption rate, we believe the three PILs solution can be recommended as alternatives to some volatile organic amines to be applied in CO2 capture.