Adsorption CO2 on Activated Carbon with Surface Modification

The success of CO₂ capture from flue gas with solid sorbent is dependent of a low cost sorbent with high CO₂ adsorption capacity and selectivity. Modifying surface texture of activated carbon with impregnating amines is expected to offer the benefits of liquid amines in the typical adsorption process routes. In this work, cocoanut activate carbon (AC) is firstly alkalified by KOH solution, then modified by impregnation of tetraethylenepentamine (TEPA), triethylenetetramine (TATA), and triethanolamine (TEA) to form a new type of sorbents. The effects of alkalifying treatment and temperature on CO₂ adsorption capacities of the sorbents are investigated. Results indicate that the activate carbons modified by combining alkalification pretreatment firstly and then impregnated amines at low temperature are profitable for CO₂ adsorption. The adsorption capacities of CO₂ are enhanced with TEPA and TETA impregnation on the activate carbon pretreated by KOH solution. And CO₂ adsorption capacity of new sorbents is stable after many adsorption and desorption cycles.