High efficient carbon dioxide capture onto as-synthesized activated carbon by chemical activation of Persian Ironwood biomass and the economic pre-feasibility study for scale-up

Abstract

The adsorption capacity of CO2 and the economic estimation of synthesized activated carbons (ACs) from Persian Ironwood biomass were evaluated in the present study. In addition, the effect of different impregnation ratios of activation agents, including KOH and H3PO4, and various carbonization temperatures on the properties of synthesized ACs was examined by different analyses. The obtained results revealed that BET surface area (SBET) and micropore volume of synthesized ACs were enhanced with an increase in the impregnation ratio of the precursor to KOH. Moreover, the synthesized AC by KOH activation with an impregnation ratio of 1:3 (precursor: activating agent), and a carbonization temperature of 1073 K demonstrated the higher SBET (1935.8 m2/g), micropore volume percentage (about 98%), and CO2 adsorption (5.05 mmol/g) at 1 bar and 303 K. Considering the thermodynamic parameters, the dominant mechanism for CO2 uptake was physisorption, spontaneous, and exothermic in nature. Furthermore, based on the annual production of 900,000 kg, the estimated capital costs for AC by KOH activation and AC by H3PO4 activation would be $1.65 and $1.58 per kg, respectively.