CO2/H2O Adsorption Equilibrium and Rates On CuBTC and Ni-DOBDC

Metal organic frameworks (MOFs) have recently attracted intense research interest because of their permanent porous structures and potential applications as novel adsorbents and catalysts. In order to provide a basis for consideration of MOFs for removal of carbon dioxide from gases containing water vapor, such as flue gas, we have considered adsorption equilibrium of carbon dioxide, water vapor, and their mixtures and also rates of adsorption on two MOFs: CuBTC and Ni-DOBDC (Ni-MOF-74). The MOFs were synthesized via solvothermal methods, and the as-synthesized products were solvent exchanged and regenerated. Adsorption equilibrium was studied using gravimetric and volumetric systems. The effects of water adsorption on the capacities for carbon dioxide were determined. Carbon dioxide adsorption rates for the MOF samples were investigated by using a unique concentration-swing frequency response system. Several transport models were examined to determine the controlling mass transfer resistance and establish rate parameters.