An Adsorbent Performance Indicator as a First Step Evaluation of Novel Sorbents for Gas Separations: Application to Metal-Organic Frameworks

An adsorbent performance indicator (API) is proposed in an effort to initially highlight porous materials of potential interest for PSA separation processes. This expression takes into account working capacities, selectivities, and adsorption energies and additionally uses weighting factors to reflect the specific requirements of a given process. To demonstrate the applicability of the API, we have performed the adsorption of carbon dioxide and methane at room temperature on a number of metal-organic frameworks, a zeolite and a molecular sieve carbon. The API is calculated for two different CO2/CH4 separation case scenarios: bulk separation and natural gas purification. This comparison highlights how the API can be more versatile than previously proposed comparison factors for an initial indication of potential adsorbent performance.