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Lithium aluminate has attracted researchers’ interests due to its wide applications. By combining electronic structural and lattice phonon thermodynamic calculations, the CO2 capture properties of γ-LiAlO2 and α-Li5AlO4 are investigated. Both γ-LiAlO2 and α-Li5AlO4 are insulators with wide band gaps of 4.70 and 4.76 eV respectively. Their 1st valence bands just below the Fermi level are mainly formed by p orbitals of Li, O and Al as well as s orbital of Li. By increasing the temperature from 0 K up to 1500 K, their phonon free energies are decreased while their entropies are increased. Targeting on developing post- and pre-combustion CO2 capture technologies, the obtained results indicated that γ-LiAlO2 is thermodynamically favorable to capture CO2 at lower temperature range (500-800 K) while α-Li5AlO4 could capture CO2 at higher temperature (800-1000 K) range in comparison with other solid sorbents, such as pure Li2O, Li4SiO4 and Li2ZrO3.
Pilot test results of post-combustion CO2 capture using solid sorbents
