A novel removal of CO2 using nitrogen doped biochar beads as a green adsorbent

This study investigated the removal characteristic of CO2 by a porous nitrogen doped biochar (AMBC) bead sorbent. The AMBC beads possessed a well-developed pore structure with a high specific surface area of 328.6 m2 g−1, which is very helpful for CO2 adsorption. In the adsorption tests carried out using a lab-scale fixed-bed column, the CO2 removal performance was further improved by increasing the porosity and the specific surface area of the sorbent. The synthesized AMBC beads exhibited a very high CO2 removal capacity of 10.15 mmol g−1 at 20 °C, which is much higher than that of commercial activated carbon and other adsorbents. The CO2 adsorption capacity of the AMBC bead was maintained at 85% of the initial bead adsorption capacity even after 10 adsorption desorption recovery cycles. The AMBC beads also showed great selectivity for CO2 (79.1) in the CO2/N2 gas mixture. The easily collected synthesized AMBC beads can be used as an effective and environmentally friendly alternative adsorbent for CO2 capture.