NOVELTY - Separating methane from natural gas mixture involves directing natural gas mixture into gas separation unit having vessel (400) with gas inlet (410), first gas outlet (430), adsorbent material, major flow channels (450), and minor flow channel; placing vessel under pressure to cause contaminants to be adsorbed to adsorbent material; releasing product stream of methane (95 volume%) from first gas outlet; and desorbing contaminant gases from material by reducing pressure within vessel without applying heat to vessel thus delivering waste gas stream comprised of contaminant gas (95 volume%).    USE - For separating methane from natural gas mixture (claimed).    ADVANTAGE - The method uses pressure swing adsorption processes that remove undesirable gas components from hydrocarbon gas stream. The method reduces cycle times and does not require large equipment footprints. The method achieves high purity production separation without the need for heating of the adsorption vessel or thermal swing operation.    DETAILED DESCRIPTION - A process for separating methane from a natural gas mixture, involves directing a natural gas mixture into a gas separation unit having at least one vessel (400) comprised of: a gas inlet (410) for receiving the natural gas mixture, a first gas outlet (430), an adsorbent material that has a kinetic selectivity for contaminants over methane greater than 5, such that the contaminants become gases kinetically adsorbed within the adsorbent material, at least two major flow channels (450) through the adsorbent material placing the gas inlet and the first gas outlet in fluid communication, and at least one minor flow channel through the adsorbent material, where the minor flow channels are in fluid communication with the major flow channels; placing the vessel under pressure to cause the contaminants to be adsorbed to the adsorbent material; releasing a product stream comprised of methane (at least 95 volume%) from the first gas outlet; and desorbing the contaminant gases from the adsorbent material by reducing the pressure within the at least one vessel without applying heat to the vessel, thereby delivering a waste gas stream comprised of contaminant gases (at least 95 volume%). An INDEPENDENT CLAIM is included for a fractionation vessel for separating methane from a natural gas mixture, comprising a housing (401); a gas inlet for receiving the natural gas mixture into the housing at a pressure of at least 100 psig; a first gas outlet for releasing at least a portion of the natural gas mixture from the housing; an adsorbent material within the housing having a kinetic selectivity for contaminants over methane greater than 5, such that the contaminants become kinetically adsorbed within the adsorbent material in gas phase; at least two major flow channels through the adsorbent material, where the at least two major flow channels place the gas inlet and the first gas outlet in fluid communication; and at least one minor flow channel through the adsorbent material, where the minor flow channel is in fluid communication with the major channels.    DESCRIPTION OF DRAWING(S) - The figure shows cross-sectional view of adsorbent bed and flow channels for pressure swing adsorption vessel.    Pressure swing adsorption vessel (400)    Housing (401)    First end (402)    Second end (404)    Adsorbent ring (405)    Gas inlet (410)    Adsorbent rods (415)    Second gas outlet (420)    First gas outlet (430)    Major flow channels (450)