Sol-gel Synthesis of Li4SiO4 Nanoparticles for CO2 Capture at High Temperature

Abstract

Removing carbon dioxide from industrial effluents (i.e. flue gas) via solid sorbents is a potential greenhouse gas mitigation strategy. Lithium orthosilicate (Li₄SiO₄) is one of the most promising materials for CO₂ capture at high temperature (500-700 °C).
In this study, the non-hydrolytic sol-gel technique was used to synthesized Li₄SiO₄ nanoparticles for improving lithium silicate features as solid sorbent for carbon dioxide. The CO₂ sorption properties of the obtained nanoparticles were investigated by using a thermal gravimetric analyzer (TGA) in a controlled gas flow environment at CO₂ partial pressure of 0.6 atm and at 700 °C. Li₄SiO₄ nanoparticles with average diameter less than 100 nm aggregated in clusters less than 500 nm were obtained. An amount of adsorbed carbon dioxide of 6.9 mmol of CO₂/g sorbent, corresponding to an 82.4 % conversion of lithium orthosilicate, was reached. The promising results could be related to high surface area of nano-size material synthesized by sol- gel process.