High-Performance Biomass-Derived Activated Porous Biocarbons for Combined Pre- and Post-Combustion CO2 Capture

This paper demonstrates the synthesis of highly efficient activated porous biocarbons through chemical activation of Lotus seed for pre- and postcombustion CO2 capture. The activation was performed at three different temperatures using four different KOH/biomass impregnation ratios. The synthesized materials are ultramicroporous and display bimodal porosity which can be easily controlled by varying the experimental conditions. The specific surface area can be tuned from 1079 m(2) g(-1) to 2230 by adjusting the amount of activating agent and the carbonization temperature. The optimized material with the highest surface area (2230 m(2) g(-1)) and pore volume (0.96 cm(3) g(-1)) showed a simultaneous high promise for both low pressure (6.8 mmol g(-1) at 1 bar/0 degrees C) and high pressure (26.4 mmol g(-1) at 30 bar/0 degrees C) CO2 capture, which is extremely difficult to achieve for any CO2 sorbent and has never been reported before. This exceptional performance is attributed to ultramicroporosity, high surface area, and surface-oxygenated functional groups. Heat of adsorption (30.4 kJ mol(-1)) value suggests that adsorption is physical in nature and accounts for easier material regeneration. These multiple merits underline the importance of synthesized materials in the field of CO2 capture and potential for various other environmental applications.