Novel CO₂ Adsorbent Prepared with ZSM-5/MCM-48 as Support: High Adsorption Property and Its Mechanism

Adsorption by solid amine adsorbent is a promising technology for decarbonization of flue gas.However, adsorption properties of many solid amine adsorbents need to be enhanced, and it is necessary to further study the CO 2 adsorption mechanism.A novel CO 2 adsorbent with high capacity was obtained by grafting 3-aminopropyltriethoxysilane (APTES) on a micro-mesoporous composite molecular sieve ZSM-5/MCM-48 as the support, and then impregnated with tetraethylenepentamine (TEPA) or polyethyleneimine (PEI).The maximum adsorption capacity of APTES-ZSM-5/MCM-48-TEPA-60 (A-ZM-T60), loaded with 60% (in mass) TEPA, for CO 2 reaches 5.82 mmolg -1 at 60 in 15% (in volume) CO 2 .Carbamate, alkyl ammonium carbamate and carbonate are generated during the chemical adsorption, which is dominant for CO 2 adsorption because of the reaction between CO 2 and amino groups on the adsorbent, simultaneously accompanied by weak physical adsorption.All above data confirm that these composites display an outstanding adsorption performance with a bright future for CO 2 capture from flue gas after desulfurization.