Porous activated carbons derived from waste sugarcane bagasse for CO2 adsorption

Business cost concern of solid CO 2 adsorbents has motivated the production of porous activated carbons from waste biomass materials. In this work, porous activated carbons were prepared from sugarcane bagasse using different activating agents (air, CO 2 , H 3 PO 4 and NaOH). Chemically activated porous carbons exhibited better physicochemical properties as compared to the physically activated carbons. Particularly, NaOH-activated carbon (CAC-S) featured a high specific surface area (1149 m 2 /g) and a large pore volume (1.73 cm 3 /g). X-ray photoelectron spectroscopy (XPS) analysis confirmed that the CAC-S adsorbent exhibited enhanced total basicity. The desired CAC-S adsorbent showed superior isothermal CO 2 uptakes of 5.50 and 4.28 mmol CO 2 /g at 0 °C and 25 °C and 1 bar. The isosteric heat of adsorption was predicted as 43.96 kJ/mol from the Clausius-Clapeyron equation and Toth model, which indicated intensified interaction between CO 2 molecules and the basic carbon surface. The excellent CO 2 adsorption performance should be associated with the improved textural properties and enriched surface basicity benefited from NaOH activation. Overall, CAC-S is considered as a promising adsorbent for CO 2 adsorption. The recycling of sugarcane bagasse as solid CO 2 adsorbents presents environmental implications with respect to waste management and pollutants mitigation.