Gas tight vessel with a diffusion barrier layer of metal hydrides
The present invention relates to a gas tight storage and/or transport tank for low molecular filling media, in particular for hydrogen, with a tank wall which comprises a thermoplastic polymer and at least one diffusion barrier. The diffusion barrier comprises a metal hydride.
1. Gas tight storage and/or transport tank ( 10 ) for low molecular filling media with a tank wall ( 12 ) which comprises a thermoplastic polymer and at least one diffusion barrier ( 18 ), wherein said low molecular filling media is hydrogen which is present in the form of a metal hydride, and said diffusion barrier ( 18 ) comprises a metal hydride which exhibits a hydrogen desorption temperature above 100° C. and wherein the hydrogen desorption temperature is lower than the hydrogen desorption temperature of the metal hydride of the diffusion barrier ( 18 ).
2. Tank ( 10 ) according to claim 1 characterised in that the metal hydride of the diffusion barrier ( 18 ) exhibits a hydrogen desorption temperature of 100° C. to 200° C.
3. Tank ( 10 ) according to claim 2 characterised in that the diffusion barrier ( 18 ) comprises sodium alanate (NaAlH 4 ).
4. Tank ( 10 ) according to claim 1 characterised in that the metal hydride of the diffusion barrier ( 18 ) exhibits a hydrogen desorption temperature above 210° C.
5. Tank ( 10 ) according to claim 4 characterised in that the diffusion barrier ( 18 ) comprises magnesium hydride (MgH 2 ).
6. Tank ( 10 ) according to claim 1 characterised in that the diffusion barrier ( 18 ) consists of a metal hydride.
7. Tank ( 10 ) according to claim 1 characterised in that the tank wall ( 12 ) comprises polyacrylic material.
8. Process for the manufacture of a tank ( 10 ) according to claim 1 characterised in that the tank wall ( 12 ) is first coated with the metal or the metal alloy of the diffusion barrier ( 18 ) and subsequently the metal hydride is formed by reaction with hydrogen.