The Application of Biochar for CO 2 Capture: Influence of Biochar Preparation and CO 2 Capture Reactors.

This work investigates three types of biochar (bamboo charcoal, wood pellet, and coconut shell) for postcombustion carbon capture. Each biochar is structurally modified through physical (H 2 O, CO 2 ) and chemical (ZnCl 2 , KOH, H 3 PO 4 ) activation to improve carbon capture performance. Three methods (CO 2 adsorption isotherms, CO 2 fixed-bed adsorption, and thermogravimetric analysis) are used to determine the CO 2 adsorption capacity. The results show that a more than 2.35 mmol·g -1 (1 bar, 298 K) CO 2 capture capacity was achieved using the activated biochar samples. It is also demonstrated that the CO 2 capture performance by biochar depends on multiple surface and textural properties. A high surface area and pore volume of biochar resulted in an enhanced CO 2 capture capacity. Furthermore, the O*/C ratio and pore width show a negative correlation with the CO 2 capture capacity of biochars.