Imidazolium-based Ionic Liquids Impregnated in Silica and Alumina Supports for CO2 Capture

Abstract

Ionic liquids (ILs) physical immobilization in solid materials is a key strategy for developing efficient and low cost CO2 capture processes. In this work, two porous commercial substrates with different characteristics (silica and alumina) were impregnated with ILs by physical wet method. Imidazolium based IL combined with [Br]- and [Tf2N]- anions were used in impregnation process. CO2 sorption capacity and selectivity (CO2/N2) of these materials were investigated. The best results regarding CO2/N2 selectivity and CO2 sorption were obtained with [Tf2N]- anion. In relation to solid support, commercial alumina exhibited enhanced CO2 uptake and higher selective capacity (CO2/N2) (6.1 (± 0.1)). Combination of commercial alumina as support and 20 wt% of mbmim [Tf2N] resulted in higher CO2/N2 selectivity of 9.5 ± 1.0. In addition, this material also showed fast sorption kinetics when compared to pure IL besides reuse capacity.

Keywords

• porous materials
• ionic liquids
• CO2 capture