Investigation of CO2 adsorption by bagasse-based activated carbon

Bagasse-based activated carbon (BAC) and amine-modified BAC were prepared and investigated for CO₂ adsorption capacity. Modifying BAC with amines resulted in a decrease of surface area, but the decreasing magnitude varied depending on type and loading rate of amines. At room temperature, the unmodified BAC was able to adsorb more CO₂ than the amine-modified BAC. This ability was related to the higher surface area of unmodified than that of the modified BAC. When temperature increased, CO₂ adsorption capacity of all absorbents was decreased. However, above 323 K and a concentration of CO₂ lower than 30% v/v, the BAC modified with PEI at 5 and 25 wt% showed higher adsorption capacity. Among all adsorbents under 15% CO₂ and 348 K, BAC-PEI25 showed the highest adsorption capacity (0.20 mmol/g).