Fly ash-derived mesoporous silica with large pore volume for augmented CO2 capture

The ordered mesoporous silica materials with large pore volume were prepared from the silica source extracted from fly ash by supercritical hydrothermal activation. This path has the advantages of low activation temperature, high silicon utilization, and matching of silicon source extraction and the hydrothermal synthesis process. The obtained mesoporous silica support was impregnated with 60 wt% tetraethylenepentamine (TEPA) to prepare excellent solid amine sorbent. The thermogravimetric results showed that the CO 2 adsorption capacity of sorbent could reach 5.17 mmol/g under 75 °C and dry pure CO 2 atmosphere. At the same time, the sorbent had fast adsorption kinetics (5.08 mmol/g in 10 min) and stable cycle performance. Consequently, the obtained sorbent is a promising candidate for carbon capture technologies.