Dynamic performance of CO₂ adsorption with amine-modified SBA-16

Novel CO₂ adsorbents for CO₂ removal were prepared by introducing tetraethylenepentamine (TEPA) into SBA-16 type mesoporous silica using a post-synthetic impregnation method. The properties of the mesoporous materials before and after surface modification were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), and N₂ adsorption-desorption. We confirmed that TEPA was loaded onto the surface of the channels in the mesoporous materials. The surface area, pore size, and pore volume of TEPA-loaded SBA-16 decreased with an increase in TEPA loading while its fundamental pore structure was unchanged. The dynamic adsorption of CO₂ onto TEPA-loaded SBA-16 as well as its regeneration property was studied in a packed column. The total adsorption capacity and breakthrough capacity increased when the amount of loaded TEPA increased from 10% to 30% (w). The sample impregnated with 30% TEPA showed the highest breakthrough capacity and total adsorption capacity of about 0.625 and 0.973 mmol·g^-1 at 60 °C, respectively. From 60 °C to 80 °C, the CO₂ dynamic adsorption behavior of TEPA-loaded SBA-16 was stable. The total adsorption capacity of CO₂ on TEPA-loaded SBA-16 dropped slightly (6.45%) after 20 adsorption-desorption regeneration cycles. Their CO₂ adsorption behavior was also investigated using the deactivation model, which showed an excellent predictive capability for the breakthrough curves.