Previously, we reported that Na-ETS-10 can be used to separate a mixture of ethylene and ethane from an industrial process stream under low pressure (101 kPa) with a binary bed selectivity of 5 at 298 K and 101.3 kPa. In this study, we show that selectivity improves considerably under high pressure conditions. Na-ETS-10 was used as a packed bed adsorbent to separate an ethylene/ethane 59141 mixture over a pressure range of 101-2580 kPa and at two different temperatures (273 and 298 K). At these pressures, pure ethane gas raffinate streams prior to ethylene breakthrough are obtained. The extract phase obtained following desorption from the packed bed column contained up to 94% ethylene. The separation performance improved as adsorption column pressures increased. The ethylene/ethane bed selectivity achieved at 298 K and 2580 kPa was similar to 11, more than double the previously reported selectivity under low pressure. (C) 2011 Elsevier Ltd. All rights reserved.