Abstract:
The effect of different polyethyleneimine (PEI) molecular weights on CO₂ adsorption on activated carbon (AC) was investigated. The PEI loading was varied by different PEI solution concentrations from 1.0 to 5.0 g/L. CO₂ adsorption isotherms were investigated at 30, 50, and 75ºC. Adsorbents were characterized by TG-DTA, FTIR, and surface area and pore size analysis. The results showed that PEI impregnated on activated carbon improved the CO₂ adsorption capacity due to the synergistic effects between physical and chemical adsorption. AC impregnated with the low molecular weight PEI showed improvement in the CO₂ adsorption capacity at a low temperature. Higher PEI molecular weights showed higher adsorption capacity at a high temperature. An optimum amount of PEI loading and appropriate PEI molecular weight are needed to increase the CO₂ adsorption capacity.
