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).