Sol-gel synthesis of Li4SiO4 nanoparticles for CO2 capture at high temperature

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.