Adsorption of Carbon Dioxide and Nitrogen in Co(ndc)(dabco) Metal-Organic Framework.

Metal-organic frameworks (MOFs) are promising materials for processes such as carbon dioxide (CO) capture or its storage. In this work, the adsorption of CO and nitrogen (N) in Co(ndc)(dabco) MOF (ndc: 2,6-naphthalenedicarboxylate; dabco: 1,4-diazabicyclo[2.2.2]octane) is reported for the first time over the temperature range of 273-323 K and up to 35 bar. The adsorption isotherms are successfully described using the Langmuir isotherm model. The heats of adsorption for CO and N, determined through the Clausius-Clapeyron equation, are 20-27 kJ/mol and 10-11 kJ/mol, respectively. The impact of using pressure and/or temperature swings on the CO working capacity is evaluated. If a flue gas with 15% CO is fed at 6 bar and 303 K and regenerated at 1 bar and 373 K, 1.58 moles of CO can be captured per kg of MOF. The analysis of the multicomponent adsorption of typical flue gas streams (15% CO balanced with N), using the ideal adsorbed solution theory (IAST), shows that at 1 bar and 303 K, the CO/N selectivity is 11.5. In summary, this work reports essential data for the design of adsorption-based processes for CO capture using a Co(ndc)(dabco) MOF, such as pressure swing adsorption (PSA).