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hydrogen gas storage question?

I want to store hydrogen gas(not browns gas) in some kind of pressure container. Since the propane tank is  not a good idea
from your forum, I was thinking about using a truck tire that could be pressurized to 120 psi.  What are the hazards in this process.
I would suck out the air from the tube tire with a vacuum pump and then generate hydrogen gas, compress it into the tire. 
Will it work or will it become unstable and blow up?.

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judas797 months ago

Related to this discussion: Is there something I can coat plastic with, to make it less permeable to hydrogen escaping at "sea level" pressure? I want to make a zeppelin toy that can float as long as possible, and it has to be plastic....

It will leak. Hydrogen is a very wriggly little molecule, and can escape through many materials.

Also, putting H2 in something like a rubber bag is just a dumb idea.

Steve
o tvedt (author)  steveastrouk4 years ago
Thanks for the response.. I am checking out the links in your answers. I have a stainless steel tank used for air storage. It holds about 15 gals. From a link in your information it sounds like this process would be safe. Let me know ifs this would be dangerous putting 120psi of hydrogen gas into a tank like this.
I think the answer depends on how much hydrogen (H2) gas you want to store, and at what pressure.


PVC pipe fittings
I think you could store a small amount of H2 inside an enclosure made of PVC pipe fittings.  PVC pipe designed  to withstand 10s of bar, or 100s of PSI, of internal pressure.  I mean that's the good stuff.  "Schedule 40" is, I think,  what they call it in the former US, and you can probably look up the specs for that.  BTW, the pressure rating gets de-rated at higher temperatures, because PVC starts to get soft, near about 100 C, the boiling point of water at standard pressure.

Also worth mentioning is there is this other kind of PVC pipe called "foamcore", or "DWV (for Drain, Waste, Vent)" That kind of PVC pipe is sold in large diameters, but it is not as strong, and not intended to withstand internal pressure.  In fact, I think they even print warnings on the side of the pipe itself, with words like "NOT FOR PRESSURE", or something like that.


Steel Bottles
Not sure why you don't want to store your H2 in a steel propane bottle?  Perhaps you are worried about the legend of hydrogen embrittlement.
http://en.wikipedia.org/wiki/Hydrogen_embrittlement

I think steel bottles are what the welding supply places use for storing H2, although I'd have check with one of those places to make sure that is the case, and also to make sure that it is not some kind of special steel that won't get embrittled.

Hydride Storage
You might have heard the legends of metal hydrides
http://en.wikipedia.org/wiki/Hydrogen_storage#Metal_hydrides
as a hydrogen storage material.  I know of one place that is selling tiny metal hydride storage cylinders, and that is this place:
http://www.horizonfuelcell.com/store_us.htm
Of course the fittings on those little HydroStik(r) things, are probably something weird, and might be hard to adapt to your thing.  Of course what they want is for you to buy every component from them:  the fuel cell, the hydride stick/bottle, and the refilling gizmo too.  The cost for all of those is several hundred USD, all to support a measly 2 watt fuel cell, at the time of this writing.

High Pressure Fittings and Bottles
A while back I came across a copy of a DVD, titled "Hydrogen Car and Multifuel", from a company called knowledgepublications.com.  Included with that DVD was a list of companies selling tanks and fittings intended for use with high pressure, i.e. 100s of bar (1000s of PSI), hydrogen.   I think these kinds of tanks are typically made out of some kind of super strong, carbon fiber composite, and these tanks are also typically not cheap.  This list is attached to this post as a text file.
I forgot to mention:  the idea of using a tire seems OK to me, just as long as you don't exceed its rated pressure.

Also I just noticed:  there's a Wikipedia page for "hydrogen tank", and who knows?  There might some clues therein:
http://en.wikipedia.org/wiki/Hydrogen_tank