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Encapsulated ionic liquid (ENIL) material was developed, consisting of ionic liquid (IL) introduced into carbon submicrocapsules. ENILs contain >85% w/w of IL but discretized in submicroscopic encapsulated drops, drastically increasing the surface contact area with respect to the neat fluid. ENIL materials were here tested for gas separation processes, obtaining a drastic increase in mass transfer rate.

The potential advantages of applying encapsulated ionic liquid (ENIL) to CO capture by chemical absorption with 1-butyl-3-methylimidazolium acetate [bmim][acetate] are evaluated. The [bmim][acetate]-ENIL is a particle material with solid appearance and 70 % w/w in ionic liquid (IL). The performance of this material as CO sorbent was evaluated by gravimetric and fixed-bed sorption experiments at different temperatures and CO partial pressures. ENIL maintains the favourable thermodynamic properties of the neat IL regarding CO absorption. Remarkably, a drastic increase of CO sorption rates was achieved using ENIL, related to much higher contact area after discretization. In addition, experiments demonstrate reversibility of the chemical reaction and the efficient ENIL regeneration, mainly hindered by the unfavourable transport properties. The common drawback of ILs as CO chemical absorbents (low absorption rate and difficulties in solvent regeneration) are overcome by using ENIL systems.

Encapsulated ionic liquids (ENILs) based on carbonaceous submicrocapsuleswere designed, synthesized and applied to the sorption of NH 3 from gas stream. The ENILs were prepared using three different task-specific ILs with adequate properties for NH 3 capture: 1-2(-hydroxyethyl)-3-methylimadazolium tetrafluoroborate (EtOHmimBF 4 ), choline bis(trifluoromethylsulfonyl)imide (CholineNTf 2 ) and tris(2hydroxyethyl)-methylammoniummethylsulfate [(EtOH) 3 MeNMeSO 4 ]. The ENILs synthesized were analyzed by different techniques to assess their morphology, chemical composition, porous structure and thermal stability. The capture of NH 3 was tested in fixed-bed experiments under atmospheric pressure. The influence of the type and load of IL, temperature (30, 45 and 60 ºC) and NH 3 inlet concentration was analyzed.Desorption of NH 3 from the exhausted ENILs was also studied at atmospheric pressure and temperatures in the range of 150 to 200 ºC. The ENILs prepared with task-specific ILs were found to be suitable for NH 3 capture in the fixed-bed operation. These systems can be a promising alternative to conventional absorption or adsorption due to: i) high sorption capacity controlled by IL selection, ii) remarkable mass transfer rate, iii) low 2 sensitiveness to high temperatures of the gas stream, iv) fast and complete regeneration of the exhausted ENIL at mild conditions; and v) recovery of NH 3 .