Abstract

We have computed the phase diagrams for multi-component M–C–O–H (M=Li, Na, K) systems using first-principles density functional theory complemented with lattice phonon calculations. We have identified all CO₂ capture reactions that lie on the Gibbs free energy convex hull as a function of temperature and the partial pressures of CO₂ and H₂O. Our predicted phase diagrams for CO₂ capture reactions are in qualitative and in some instances quantitative agreement with experimental data. The Na₂CO₃/NaHCO₃ and K₂CO₃/KHCO₃ systems were found to be the most promising candidates of all those we investigated for both pre- and post-combustion CO₂ capture. Overall, we show that our calculation approach can be used to screen promising materials for CO₂ capture under different conditions of temperature and pressure.

Graphical abstract

The calculated results indicate that the Na₂CO₃/NaHCO₃ and K₂CO₃/KHCO₃ systems are the most promising candidates of all those we investigated for both pre-and post-combustion CO₂ capture.

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