Abstract
MOFs are potential adsorbents for methane separation from nitrogen, including recovery in diluted streams. However, water and carbon dioxide can seriously affect the adsorption performance. Three commercial MOFs, basolite C300, F300, and A100, were studied under similar conditions to fugitive methane streams, such as water (75 and 100% relative humidity) and carbon dioxide (0.33%) presence in a fixed bed. The presence of available open metal sites of copper (Cu2+) and aluminum (Al3+) in the case of basolite C300 and A100, respectively, constitutes a clear drawback under humid conditions, since water adsorbs on them, leading to significant methane capacity losses. Surprisingly, basolite F300 is the most resistant material due to its amorphous structure, which hinders water access. The combination of carbon dioxide and water creates a synergy that seriously affects basolite A100, closely related to its breathing effect, but does not constitute an important issue for basolite C300 and F300.