Regresar

High-Performance Materials Based on Lithium-Containing Hydrotalcite-Bayerite Composites for Biogas Upgrade

Abstract:

To upgrade biogas, carbon dioxide has to be selectively removed from methane. Lithium ceramics have been found to be efficient materials for the retention of CO2 at temperatures as high as 800 °C. However, they do not perform well at low temperatures. In this work, lithium hydrotalcites with various Li:Al ratios were synthesized in the presence of microwave irradiation. The effects of irradiation time, lithium content, and precipitation pH on the structure and textural features were studied. The resulting materials contained bayerite and were tested for the reversible adsorption of CO2 or CH4 at room temperature, resulting in an isosteric heat of 12 kJ/mol for CO2 and an insignificant adsorption of CH4. Furthermore, to prove the efficiency of these materials in biogas purification, a sample was used for the separation of CO2 from synthetic biogas. The results show that Li-hydrotalcite/bayerite composites are promising materials for biogas upgrading at room temperature.