Separation of hydrogen from mixed gases through precious-metal separation membranes

Gas-separation membrane tubes with a PVD palladium surface.
© Fraunhofer IST, Falko Oldenburg
Gas-separation membrane tubes with a PVD palladium surface.

Economical production of small and medium quantities of hydrogen

Hydrogen can be produced by steam reforming of natural gas. In this process, natural gas is mixed with steam and this mixture is passed over catalyst particles, whereby hydrogen molecules and carbon oxides are produced in an endothermic reaction at operating temperatures of approx. 600 °C. When this gas mixture encounters a palladium surface, the hydrogen diffuses through the metal and can be extracted on the other side for further processing.

Loss-free PVD application of noble metal to membrane substrates

In collaboration with an industrial partner, the Fraunhofer IST has already been successful in depositing thin layers of noble metal on membrane materials with a porosity of approx. 40 vol. % which are highly permeable to gas and which form the carrier material for the thin Pd membranes. The leakage rate of the Pd membrane significantly determines the performance capability of the system and should be as low as possible.

 

Further information

 

Palladium gas separation membranes