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 (Li[subscript 4]SiO[subscript 4]) is one of the most promising materials for CO2capture at high temperature (500-700 °C). In this study, the non-hydrolytic sol-gel technique was used to synthesized Li[subscript 4]SiO[subscript 4] nanoparticles for improving lithium silicate features as solid sorbent for carbon dioxide. The CO[subscript 2] sorption properties of the obtained nanoparticles were investigated by using a thermal gravimetric analyzer (TGA) in a controlled gas flow environment at CO[subscript 2] partial pressure of 0.6 atm and at 700 °C. Li[subscript 4]SiO[subscript 4] 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 CO[subscript 2]/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.©2020