Enhanced CO₂ Capture through SAPO-34 Impregnated with Ionic Liquid

Abstract

The concurrent utilization of an adsorbent and absorbent for carbon dioxide (CO 2 ) adsorption with synergistic effects presents a promising technique for CO 2 capture. Here, 1-butyl-3-methylimidazole acetate ([Bmim][Ac]), with a high affinity for CO 2 , and the molecular sieve SAPO-34 were selected. The impregnation method was used to composite the hybrid samples of [Bmim][Ac]/ SAPO-34, and the pore structure and surface property of prepared samples were characterized. The quantity and kinetics of the sorbed CO 2 for loaded samples were measured using thermogravimetric analysis. The study revealed that SAPO-34 could retain its pristine structure after [Bmim][Ac] loading. The CO 2 uptake of the loaded sample was 1.879 mmol g −1 at 303 K and 1 bar, exhibiting a 20.6% rise compared to that of the pristine SAPO-34 recording 1.558 mmol g −1 . The CO 2 uptake kinetics of the loaded samples were also accelerated, and the apparent mass transfer resistance for CO 2 sorption was significantly reduced by 11.2% compared with that of the pure [Bmim][Ac]. The differential scanning calorimetry method revealed that the loaded sample had a lower CO 2 desorption heat than that of the pure [Bmim][Ac], and the CO 2 desorption heat of the loaded samples was between 30.6 and 40.8 kJ mol −1 . The samples exhibited good cyclic stability. This material displays great potential for CO 2 capture applications, facilitating the reduction of greenhouse gas emissions.