First assessment of Li2O–Bi2O3 ceramic oxides for high temperature carbon dioxide capture

Abstract

The capacity to capture CO2 was determined in several stoichiometric compositions in the Li2O–Bi2O3 system. The compounds (Li7BiO6, Li5BiO5, Li3BiO4 and LiBiO2 phases) were synthesized via solid-state reaction and characterized by X-ray diffraction, scanning electron microscopy and N2 adsorption techniques. The samples were heat-treated at temperatures from 40 to 750°C under the CO2 atmosphere to evaluate the carbonate formation, which is indicative of the capacity of CO2 capture. Moreover, Li7BiO6 shows an excellent CO2 capture capacity of 7.1mmol/g, which is considerably higher than those of other previously reported ceramics. Li7BiO6 is able to react with CO2 from 240°C to approximately 660°C showing a high kinetic reaction even at CO2 partial pressure values as low as 0.05.