CO2 sorption using encapsulated imidazolium-based fluorinated ionic liquids
Franciele L. Bernard, Evandro Duarte, Bárbara B. Polesso, Rafael Duczinski, Sandra Einloft
Abstract
The development and testing of new sorbents for the efficient removal of CO2 from flue gases is essential. Encapsulated room-temperature ionic liquids (RTILs) can be potentially employed in CO2 capture. In this work, we report the preparation and characterization of encapsulated imidazolium-based fluorinated RTILs for CO2 capture. [Emim][TF2N], [Bmim][TF2N], and [Hmim][TF2N] RTILS were encapsulated in polysulfone (PSF) using an emulsification method and characterized by several techniques. The pressure-decay technique was used to assess the CO2 sorption capacity and reusability. Encapsulated RTILs showed improved utility for CO2 capture processes compared with non-encapsulated RTILs, including higher CO2 sorption capacity and faster CO2 sorption/desorption. The CO2 absorption/desorption cycles demonstrated the reuse capacity of all microcapsules under mild conditions. The highest CO2 sorption capacity was noted for encapsulated [Emim][TF2N] (39.5 mg CO2 g−1 at 298.15 K and 1 bar; 62.7 mg CO2 g−1 at 298.15 K and 10 bar). It is worth emphasizing that the encapsulated [Emim][TF2N] contained a lower ionic liquid (IL) content (37.5. ± 0.6) when compared to other encapsulated samples. Moreover, encapsulated [Emim][TF2N] presented a higher CO2 affinity than the encapsulated ILs reported in the literature.