Utilizing silica fume and synthetically produced mesoporous silicas for simulated flue gas CO adsorption.

Carbon capture and storage (CCS) is crucial in mitigating greenhouse gas emissions. Solid adsorbents, notable for their reusability and corrosion resistance, are gaining attention in CO gas separation. This study uses Silica fume as an adsorbent and silica source for SiO and MCM-41 silica-based adsorbents. Silica was extracted via an alkaline dissolution method, and adsorbents were synthesized using a CO-induced precipitation method, chosen for its shorter synthesis time and CO utilization. The effects of pore volume, average pore diameter, and specific surface area on amine loading and CO adsorption capacity were investigated using CTAB surfactant in SiO synthesis, resulting in MCM-41. The synthesized adsorbents were modified with TEPA and DEA amines due to their high affinity for CO. After determining optimal amine loading, the impact of combining TEPA with DEA was examined. The highest CO adsorption capacity under simulated flue gas conditions (15% volume CO and 85% volume N) was 198 milligrams per gram of adsorbent for the SiO adsorbent functionalized with 50% by weight amine (28% TEPA and 22% DEA). Variations in CO adsorption over time, the influence of adsorbent quantity on adsorption capacity, the affinity of the adsorbent for N adsorption, and the adsorption-desorption cycle were investigated. The 28%TEPA-22%DEA-SiO adsorbent emerged as the optimal choice due to its large total volume and average pore diameter, absence of a template in its structure, excellent performance in CO adsorption, lack of affinity for N, and robust adsorption-desorption stability.