Zeolite adsorbents are widely used for the removal of contaminants from natural gas. Typically, raw natural gas is passed through packed columns, obtaining a methane-rich stream suitable for pipeline transmission or further processing. After defined service time, bed regeneration is requested. Adsorbent chemical composition is a key parameter influencing both specific capacity and regenerability. A case-study, concerning Na-FAU zeolites applied for carbon dioxide bulk removal from natural gas, is discussed. (C) 2011 Elsevier Ltd. All rights reserved.