Stopping Helium/Hydrogen Storage Leaks.

[mastermenthe]

Liquid Helium is a very small and electrically neutral element under high pressure; it will slowly slip through the molecular structure of any given container.
Liquid Hydrogen is an extremely small element under high pressure, and it will also slowly escape any given container.

A storage container for Liquid Helium/Hydrogen placed inside of a storage container of liquid Nitrogen at greater pressure than the Helium/Hydrogen, may work as a mechanical method of containing the helium/hydrogen.

 

[Baluncore]

The inner container that separates the small / large molecules must be impervious to the larger molecules. One problem is the very low temperatures involved. At room temperature the inner container could be a balloon or bladder but that is not possible at low temperatures.

The use of a vacuum flask to insulate a cold liquefied gas would provide a way to capture any lost gas. The vacuum chamber would capture gas that bleeds through the inner wall. The bleed gas could be re-compressed and returned to the inner flask.

What pressures and temperatures are you contemplating? Under what conditions and in what applications is it more economic to contain the molecules than to replace them?

 

[Q_Goest]

Liquid Helium is a very small and electrically neutral element under high pressure; it will slowly slip through the molecular structure of any given container.
Liquid Hydrogen is an extremely small element under high pressure, and it will also slowly escape any given container.

Liquid helium and hydrogen are commonly used in large quantities throughout industry. They are stored and shipped in vacuum insulated storage tanks. A typical truck trailer used for shipping carries 9000 to 14,000 gallons of liquid helium or hydrogen. The tanks do not see helium or hydrogen getting into the vacuum space unless there's a crack in the vessel or pipe. The molecules of helium or hydrogen might pass through steel but it would take thousands of years for any measurable amount to do so on a typical storage container.

A storage container for Liquid Helium/Hydrogen placed inside of a storage container of liquid Nitrogen at greater pressure than the Helium/Hydrogen, may work as a mechanical method of containing the helium/hydrogen.

If you're suggesting to put an uninsulated helium or hydrogen tank inside a tank of liquid nitrogen, that won't work. The heat flux from the helium or hydrogen into the nitrogen would be horrific. Nitrogen freezes at a temperature well above what helium and hydrogen can remain a liquid at, so the helium and hydrogen would rapidly boil off and the nitrogen would freeze.

There are some excellent designs for helium and hydrogen storage tanks in the industry. You may want to find out a bit about how they work before making your own suggestions. Try "Cryogenic Systems" by Randall Barron.
http://books.google.com/books/about/Cryogenic_systems.html?id=G8FTAAAAMAAJ

 

[mastermenthe]

I now see now that my concept is very half-baked.
Thanks you both for taking the time to share your knowledge!