Methane/ethane separation was achieved using Na-ETS-10 as a packed-bed adsorbent over a pressure range of 450-5600 kPa at 298 K. At these pressures, pure methane gas raffinate streams were obtained prior to ethane break through. The extract phase obtained following desorption from the packed-bed column was enriched in ethane. Extract phases containing upto 75% ethane were achieved following separations of a 93/7 methane/ethane feed mixture. Separation performance did not deteriorate as adsorption column pressures increased. Selective adsorption of a synthetic natural gas mixture using an Na-ETS-10 packed-bed column resulted in hydrocarbon outlet compositions ranging from pure methane (upto similar to 60 bed volumes at standard temperature and pressure) to similar to 93% methane, similar to 5% ethane and similar to 2% propane (similar to 150 to similar to 850 bed volumes at standard temperature and pressure). In all cases, following desorption, the extract phase was highly enriched in the larger and more valuable hydrocarbons. (C) 2011 Elsevier Ltd. All rights reserved.