Carbon dioxide absorption and desorption properties of Ba₃Al₂O₆

抄録

Ba₃Al₂O₆ 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 Ba₃Al₂O₆ and CO₂ has been expressed as 1/2Ba₃Al₂O₆ + CO₂ = 1/2BaAl₂O₄ + BaCO₃, and the corresponding thermodynamic calculations were also carried out in the present study. Ba₃Al₂O₆ 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 Ba₃Al₂O₆ 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.