Porous carbons from hydrothermal carbonization of corn stover for highly efficient CO2 capture

Abstract

Abstract. Sustainable biomass-derived carbon materials were produced by hydrothermal carbonization of corn stover that was followed by chemical activation with KOH. The prepared carbon materials were used for CO 2 adsorption, and had a CO 2 uptake of 7.14 mmol/g at a pressure of 1 bar and at 0 o C that was much higher than CO 2 uptake by activated carbon that was prepared from direct activation of corn stover (2.78 mmol/g). The porous corn stover-derived carbonaceous material had high surface area (2442 m 2 /g) and large pore volume (1.55 cm 3 /g). Product yields obtained by activation of hydrothermally carbonized corn stover were significantly higher than that by the direct activation of corn stover (36-75% VS. 8%). The prepared corn stover-derived porous carbon had a high CO 2 /N 2 selectivity of 15.5, and exhibited constant CO 2 uptake for five successive reuse cycles. The hydrothermal carbonization step plays important role for producing porous carbons from biomass that have high and specific adsorption properties.