(456e) Humid Post-Combustion CO2 Capture By Vacuum Swing Adsorption Using a Hydrophobic Metal-Organic Framework CALF20

Calgary Framework (CALF)20 is a scalable, highly water-resistant metal-organic framework (MOF) that shows exceptional CO₂ selectively with high capacity. The pure adsorption and the multi-adsorption of H₂O, CO₂, and N₂ were fully characterized using volumetric, gravimetric, and dynamic column breakthrough techniques. The water isotherms exhibited a type V isotherm with an inflection point and a narrow hysteresis loop. The adsorption kinetics and column dynamics were simulated successfully using a detailed model including all dispersion, heat transfer, mass transfer and pressure drop. Below 40% relative humidity (RH), CALF20 preferentially adsorbs CO₂ over H₂O, making it possible to capture CO₂ also in moist conditions. The ability to capture CO₂ of CALF20 was modelled and optimized. The obtained optimizations were also translated into experiments under both dry and wet conditions. Basic four-step and four-step with light-product pressurization configurations were chosen to evaluate the performance of CALF20. A good agreement was observed between the predictions and the experiments. Both wet and dry cycles showed a similar purity, recovery and productivity, indicating that CALF20 can separate CO₂ under the presence of water. CALF20 also shows excellent cyclic stability with negligible reduction in CO₂ capacity after exposure to water vapour over 10,000 cycles.