Insights in high pressure adsorption of H2 and CH4 in microporous material

A.A. GARCÍA BLANCO; A. VALLONE; A. GIL; K. SAPAG

Granada

Simposio; 10th International Symposium on the characterization of Porous Solids-COPS X; 2014

The study of gas adsorption at high pressures has had an increasing interest due to the possibility of using adsorption in the storage of H2 or CH4 and in CO2 sequestration. However, there are still open questions regarding the mechanism of gas adsorption at high pressures, especially at temperatures higher than the critical temperature of the adsorbate. One the most important aspects which are still under discussion is related with the state of the adsorbed phase at these conditions; and regarding the mechanism of adsorption there are still open discussions if adsorption at these conditions follows a micropore filling or a layer formation mechanism [1-3].In order to contribute to the study of this topic, there were measured CH4 and H2 adsorption isotherms at 298 K and 77 K, respectively, at intermediate pressures (up to 3.5 MPa) in porous materials with different characteristics: surface chemistry, pore size and geometry (MOFs, zeolites and activated carbons). In these studies were analyzedfactors which could affect the adsorption capacity of porous materials, such as the adsorbate-adsorbent interaction and pore size and geometry. Finally, the behaviour of adsorption at these conditions using the characteristic curves of adsorption of Dubinin-Polanyi theory and the density of the adsorbed phase are discussed.