Facile Preparation of Porous Carbon Derived from Industrial Biomass Waste as an Efficient CO2 Adsorbent

A porous carbon CO 2 adsorbent based on soybean cake (industrial biomass waste) has been successfully prepared by direct carbonation, following KOH activation. The prepared porous carbon adsorbent exhibits efficient CO 2 capture performance with the highest adsorption capacity of 4.19 and 6.61 mmol/g at 298 and 273 K under atmospheric pressure, respectively. Moreover, the porous carbon adsorbent also shows good static CO 2 adsorption capacity at a low pressure (0.15 bar) with an uptake of 1.26 mmol/g and an equally ideal dynamic CO 2 capture capability with an uptake of 1.28 mmol/g (15% CO 2 ) at 298 K. Additionally, the ideal adsorbed solution theory (IAST) model has been used to measure the selectivity of the porous carbon, and the IAST factors of CO 2 /N 2 (15/85, fuel gas), CO 2 /CH 4 (40/60, biogas), and CH 4 /N 2 (50/50, coalbed gas) are about 27, 6, and 6, respectively. The dynamic breakthrough test reveals the strong interaction between the porous carbon and CO 2 , which also verifies the considerable selective capture ability of this material for CO 2 . Furthermore, the soybean cake-based CO 2 adsorbent also presents prominent cyclic regeneration capacity (a five-time cyclic test) with lower isosteric heats (34-18 kJ/mmol) of CO 2 adsorption.