2016 Volume 59 Issue 4 Pages 109-117
The aim of this review is to provide some information on the CO2 absorption property of ionic liquids and the CO2 permselectivity for the separation membranes using ionic liquids. Ionic liquids are a unique solvent, of which the characteristics are non-volatile, non-flammable, miscible with various chemicals, and so on. The CO2 capture using ionic liquids is a promising technology, and a variety of studies have been reported on the natures of the ionic liquid absorbents and membranes. This review presents some fundamental data on the following three topics: (1) the CO2 solubility in the ionic liquid physical absorbents; (2) the high-pressure CO2 absorption behavior for the ionic liquid chemical absorbents; (3) the CO2 permselectivity for the inclusion membranes with ionic liquids and polymers. The first two topics describe the effects of the chemical structures of ionic liquids on the CO2 solubility, in particular, in terms of the oxygen containing groups and the interionic interactions. The second topic also contains how amino acid anions affect the physical and chemical absorptions under high CO2 pressure conditions. The last topic reported that the CO2 and N2 permeations in the inclusion membranes depend on the composition and kind of polymers.
