Influence of TEPA loading on biochar based CO2 capture

“The sorption of CO₂ was performed on a breakthrough adsorption setup. In dry SFG containing 15% CO₂/N₂ 85%, the adsorption capacity of CO₂ was tested for CBC-X-TEPA adsorbent (at 101 kPa, 60 °C). Figure 7a,b shows breakthrough adsorption curves and CO₂ adsorption capacities of the adsorbent, which gradually increased as the TEPA loading increased from 20% to 50%; the adsorption time extended, as shown in Figure 7a, and reached a maximum value of 2.82 mmol g⁻¹ at 50% TEPA, as shown in Figure 7b. The large pore volume of the CBC provided a large space for the loading of TEPA, which could allow a sufficient amount of amine to penetrate the pore and provide more adsorption sites for CO₂ adsorption.” https://doi.org/10.3390/atmos13040579

“Figure 7. Breakthrough adsorption curves of CO₂ (a), and CO₂ adsorption capacity and TEPA efficiencies of CBC-X-TEPA (b).”

“The adsorption capacity started to decrease at 60% TEPA loading, which was because the pores of the adsorbent were blocked so that CO₂ only reacted with the amine-based active sites loaded on the surface of the CBC. In contrast, the organic amines immersed in the pores could not function and reduced CO₂ adsorption capacity. When the amine efficiency was 8.05 mmol g⁻¹, the adsorption capacity of the adsorbent began to decrease, and the adsorbent reached the optimal load of the amine group.” https://doi.org/10.3390/atmos13040579