Computational Study of Mixing Solid Materials for CO₂ Capture Technology

CO₂ is one of the major combustion products that, once released into the air, can contribute to global climate change. Solid sorbents have been reported as promising candidates for CO₂ sorbent applications due to their high CO₂ absorption capacities at moderate working temperatures. By combining thermodynamic database mining with first-principles density functional theory and phonon lattice dynamics calculations, the National Energy Technology Laboratory has proposed and validated a theoretical screening methodology to identify the most promising CO₂ sorbent candidates from a vast array of possible solid materials. The advantage of this method is that it identifies the thermodynamic properties of the CO₂ capture reaction as a function of temperature and gas pressure without any experimental input beyond crystallographic structural information of the solid phases involved. The calculated thermodynamic properties of solid materials versus temperature and pressure changes were further used to evaluate the equilibrium properties for the CO₂ adsorption/desorption cycles. The selected CO₂ sorbent candidates were further considered for experimental validations. In this presentation, the results of M₂O/Al₂O₃ (M=Li, Na, K) mixtures (MAlO₂ and M₅AlO₄) capturing CO₂ will be demonstrated in detail.