Apr 20, 2016, 07:20 PM
Canoeist
United States, PA, Forest Lake
Joined Mar 2011
37 Posts
Discussion
Storing Hydrogen

Hello all,

WARNING THIS IS A RATHER LONG AND BORING POSIT ON STORING
HYDROGEN. IF YOU ARE NOT INTO HYDROGEN IT MAY NOT BE GOOD

Given that one would like to store 40 ft3 of hydrogen in N
number of 55 gallons drums where the gauge pressure would
be reasonable (say 20 - 30 psi gauge).

Given 55 gallons = 7.35 ft3 and Boyle's law P1*V1 = P2*V2:
Then: Pdrum * Vdrum = Pblimp * Vblimp or:
Pdrum * 7.35 = Pblimp * 40

Pdrum = Pblimp * 40/ 7.35 = Pblimp * 5.44

But what is the pressure in the blimp (Pblimp) ?

I gather one could use a pressure slightly above standard
atmospheric pressure which is (14.7 psi or 1.03 kg/cm2 ) see
note below. Lets say 15 psi or 1.05 kg/cm2.

So Pdrum = 15 * 5.44 = 81.6 psi or 5.7 kg/cm2 that is a lot
for steel drum?

For three drums then = 27.21 psi or 1.9 kg/cm2 that should be
save enough.

These blue plastic shipping containers/drums blow at
around 65 lbs.

Now what would one use as pump? One needs a "hose" on
each end of the pump to move the gas from the blimp to the
drum. Pressure in the drums moves the gas to the blimp I
would think.

Also inflating the blimp directly from the hydrogen generator
means that the generator only needs to work into low
pressure of the blimp rather then trying to pump from the
generator to the drums in small quantities at a time.

Does that seem correct? Don't want to make my own
hydrogen bomb!

Note:
"pressure airships, maintain their shape only because the
pressure inside the envelope, or gas bag, is slightly higher
than the external air pressure.."
http://blog.nasm.si.edu/aviation/blimp/

When I inflated a latex balloon I could not get a reading on the
gauge as the pressure was to low. See photo.