TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The support is made of a ceramic material, which is alumina. The gas-selective capting material comprises zeolite crystals, where the zeolite is MFI.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: In the membrane, some pores, preferably all pores have a size of 0.3 and 0.4 mu m. The membrane has no surface film of gas-selective material on top of the support. The support is: cylindrical and has a diameter of over 1 (preferably 1.7) mm and/or a length of over 15 (preferably over 23) cm; symmetrical; and has a mean wall thickness of less than or equal to 500 (preferably less than or equal to 230) mu m. The support has an average crossing pore size of less than or equal to 0.2 mu m. The gas separation apparatus comprises a pressurizing device adapted to set a trans-support wall differential pressure of 0.1-1 kPa and to generate an in-flow of gas having a pressure of 50-500 kPa. The device further comprises a cooling unit adapted to cool the exhaust gas prior to insertion into the separating unit, a liquefying device adapted to liquefy permeated carbon dioxide gas and a device adapted to place permeated carbon dioxide in supercritical state. In the device, the membrane has a surface of over 300 (preferably over 350) m2, in a volume of less than or equal to 300 (preferably less than or equal to 240) l. The separating unit comprises at least many cascaded membranes and the intake of a further membrane is fluidly connected to the permeate of the previous membrane. The device comprises pressurizing mean adapted to generate a pressure of the permeate lower than 50 kPa, preferably lower than 30 kPa. In the device, at least one membrane has a separation factor of at least 10, preferably at least 20. The membrane further comprises cations e.g. sodium in the zeolite structure, where the support is hydrophobic. Preferred Method: The embedding comprises: pore-plugging synthesis; or at least one of mixing a structure directing agent and a silica source, submitting the support to hydrothermal synthesis in an autoclave comprising the mixing or calcinating the support. The hollow support is manufactured by wet spinning.