Enhanced CO2 capture by cupuassu shell-derived activated carbon with high microporous volume

Here, we report the preparation of microporous-activated carbons from a Brazilian natural lignocellulosic agricultural waste, cupuassu shell, by pyrolysis at 500 C and KOH activation under different experimental conditions and their subsequent application as adsorbent for CO2 capture. The effect of the KOH:precursor ratio (wt/wt%) and the activation temperature on the porous texture of activated carbons have been studied. The values of specific surface area ranged from 1132 to 2486 m(2)/g, and the overall micropore volume ranged from 0.73 to 1.02 cm(3)/g. Carbons activated with 2:1 ratio of KOH and activation temperature of 700 C presented a CO2 adsorption at 1 bar of 7.8 and 4.4 mmol/g at 0 degrees C and 25 C, respectively. The isosteric heat of adsorption, Q(st), was calculated for all samples by applying the Clausius-Clapeyron approach to CO2 adsorption isotherms at both temperatures. The values of CO2 adsorption capacities are among the highest reported in the literature, especially for activated carbons produced from biomass.

Automated summary

In this study, microporous-activated carbons were prepared from cupuassu shell and used for CO2 capture. The effect of KOH:precursor ratio and activation temperature on the porous texture of activated carbons was investigated. The activated carbons showed high CO2 adsorption capacities, with values among the highest reported in the literature for biomass-derived activated carbons.