Silica Nanoparticles as Supports for Regenerable CO₂Sorbents

This paper describes the capture of CO 2 by polyethylenimine (PEI) physically adsorbed on the surface of silica nanoparticles. The resulting material proved to be not only regenerable but also having the right qualities needed for a practical utilization, including absorption not only from high concentration streams like flue gases and natural gas wells but also from the air itself. Polyethyleneglycol (PEG) was used as a coadditive. The effect on CO 2 capture of temperature, supports, and concentrations of polyethylenimine and polyethyleneglycol was evaluated. Based on the results, the PEI and PEG concentrations were optimized to obtain a material with optimal CO 2 absorption characteristics. The obtained material demonstrated the practical possibility to capture CO 2 using an inexpensive, easy-to-prepare, and regenerable absorbent.