Carbon dioxide absorption and desorption properties of Ba33Al2O6

Abstract

Ba33Al2O6 was successfully synthesized by using solid-state reaction between BaCO3 and Al2O3 powers. The phase structure and morphologies of product were characterized by X-ray diffraction and scanning electron microscopy, respectively. The reversible reaction between Ba33Al2O6 and CO2 has been expressed as 1/2Ba33Al2O6 + CO2 = 1/2BaAl2O4 + BaCO3, and the corresponding thermodynamic calculations were also carried out in the present study. Ba33Al2O6 was found to capture CO2 over a wide temperature range with a maximum weight increase of 15.68%. The kinetics of absorption and desorption reactions between Ba33Al2O6 and CO2 were investigated by thermogravimetry, at various temperatures under different partial pressures of CO2. Based on the kinetic analyses, the absorption process of CO2 is controlled by the diffusion in the inner solid product layer, and its kinetics can be described by the widely used Ginstling-Brounshtein function, with the activation energies extracted to be 14.11, 13.85 and 12.89 kJ/mol when the concentration of CO2 are 10, 50 and 100% CO2, respectively.