Dynamic performance of CO₂ adsorption with tetraethylenepentamine-loaded KIT-6

A promising adsorbent for CO₂ removal from flue gas was prepared by introducing tetraethylenepentamine (TEPA) into KIT-6 type mesoporous silica using post-synthetic impregnation. The as-prepared adsorbents were characterized by X-ray powder diffraction (XRD), thermal gravimetric analysis (TGA), nitrogen adsorption/desorption as well as adsorption-column-breakthrough measurements. Surface area, pore size and pore volume of TEPA-loaded KIT-6 adsorbent decrease with the increasing of TEPA loading, while its fundamental pore structure is unchanged. The dynamic adsorption capacity increases from 1.5mmol/g-adsorbent to 2.9mmol/g-adsorbent when the amount of loaded TEPA increases from 10wt.% to 50wt.% at 333K. The net adsorption capacity is about 72% of dynamic adsorption capacity. Regarding the regeneration performance of CO₂ adsorbent, the suitable desorption temperature is nearly 373K. The dynamic adsorption capacity drops slightly (about 5%) during forty cycles of adsorption/desorption. The adsorbent of KIT-6 modified by TEPA exhibits excellent CO₂ adsorption/desorption performance.