Gas Separation Process for CO2 Removal from Natural Gas with DDR-type Zeolite Membrane☆

Abstract The DDR-type zeolite membrane (DDR Membrane) with an aperture of 0.36 × 0.44 nm was formed on a porous alumina substrate by hydrothermal process. We have succeeded in scaling up the DDR Membrane element into a large monolithic structure with a diameter and length of 180 mm and 1,000 mm, respectively. The CO 2 /CH 4 selectivity exceeded 100 for mixed gas of 70 mol% CO 2 at 8.0 MPag, 45 degC. This high selectivity improves hydrocarbon recovery compared to the conventional polymeric membrane. The DDR Membrane is suitable for CO 2 separation for high CO 2 natural gas fields.