“The adsorption capacity of biochar for CO2 at 0 °C and 60 °C was also tested. At low temperatures (0 °C, pure CO2), biochar with high microporosity has a high physical adsorption capacity for CO2, 4.17 mmol g−1. At 60 °C, the capacity of biochar with high microporosity to adsorb CO2 is low, only 0.76 mmol g−1, and micropores are no longer the dominant factor for CO2 adsorption. The results of pore-size analysis showed that the micropores in the biochar after TEPA modification were greatly reduced, and more mesopores and macropores were retained. At 60 °C, the CO2 adsorption experiment results show that the adsorbent has a high CO2 adsorption capacity, mainly due to the chemical reaction between the amine group and CO2, and the adsorption at this time is mainly chemical adsorption. It can be seen that the effect of micropores on chemisorption is not significant. In general, in the adsorption of CO2 at 60 °C, the adsorbent CBC-50-TEPA was mainly used for chemical adsorption. At the same time, there was also some physical adsorption caused by biochar CBC.”
