Coffee grounds derived N enriched microporous activated carbons: Efficient adsorbent for post-combustion CO2 capture and conversion

Abstract

N enriched microporous active carbons (CACs) were successfully obtained with coffee grounds as precursor and KOH as activator, which were used for the capture and conversion of CO₂ from post-combustion. The influence of preparation parameters, such as the temperature of activation and KOH/carbon ratio on textural properties of CACs were studied. N₂ adsorption-desorption, XRD, Raman, SEM and XPS were used for characterization of the CACs. The adsorption capacities of CO₂ CACs-2-800 are 6.22 mmol·g^-1 (1 bar) and 2.37 mmol·g^-1 (0.15 bar) at 273 K. CACs-2-800 also have high selectivity of CO₂/N₂ (S_CO2/N2 = 33) and good adsorption-desorption recycle stability. Furthermore, the CACs-2-800 showed high catalytic activity for the cycloaddition of CO₂ to epichlorohydrin. The good CO₂ adsorption capacity, selectivity and catalytic performance indicated that CACs-2-800 could be used for the capture and conversion of CO₂ from post-combustion.

Keywords: Adsorbent; CO(2) capture; Coffee grounds; Conversion; Microporous activated carbons.