Preparation and CO2 Sorption of a High Surface Area Activated Carbon Obtained from the KOH Activation of Finger Citron Residue

A high surface area activated carbon was synthesized by potassium hydroxide (KOH) activation of Finger Citron residue. The pore structure of the as-synthesized activated carbon was characterized by nitrogen adsorption and its carbon dioxide (CO2) sorption capacities at different conditions were measured under high pressure. The BET surface area and total pore volume of the as-synthesized sample were 2887 m(2)/g and 1.23 cm(3)/g, respectively. The dry sample exhibited a CO2 adsorption capacity of 19.21 mmol/g at 276 K and 3.57 MPa. The CO2 adsorption uptake increased considerably when an amount of water was pre-adsorbed onto the sample, possibly as a result of the formation of CO2 hydrate in the pore spaces of the activated carbon. The maximum CO2 adsorption capacity of the wet sample was found to be 29.02 mmol/g at 273 K and 3.57 MPa. Overall, the results reported confirm that Finger Citron residue could prove a promising precursor for high surface area activated carbon and point to the potential application of activated carbon made from Finger Citron residue in carbon capture and storage.