Polyimide asymmetric membranes for hydrogen separation: Influence of formation conditions on gas transport properties

The asymmetric flat sheet membrane was developed for separation of hydrogen from its mixture with other gases. The composition of the casting solution and conditions of membrane preparation were optimized for the pilot scale membrane production. The resulting membrane have a high hydrogen flux (1 m(3) (STP)/m(2)h*bar) and selectivity of H-2/CH4 at least 100, the value close to intrinsic selectivity of Matrimid 5218, material used for the assymmetric structure formation. The membrane is stable against mixtures of liquid hydrocarbons and can withstand heating up to 200 degrees C. The non-woven fabric used as a support for the asymmetric membrane gives to the membrane excellent mechanical properties and allows to use the membrane in GKSS gas separation modules.