Re: Storing H2 at high pressure or cryogenically.

On Jan 1, 4:06 pm, Don Lancaster <d...@xxxxxxxxxx> wrote:
Bob Eld wrote:
"Eeyore" <rabbitsfriendsandrelati...@xxxxxxxxxxx> wrote in message
news:477760ED.B9D4B5A6@xxxxxxxxxxxxxx

I never was that brilliant at using the gas laws.

Any ideas (or calculations ideally!) how much energy would be needed to
compress stp hydrogen to the 350 or 700 bar figures mentioned here ?

http://www.prnewswire.com/cgi-bin/stories.pl?ACCT=104&STORY=/www/stor...
-2002/0001761919&EDATE=

I know it depends on temperature rise too, but even assuming it could be
achieved isothermally ? with high efficiency pumps just how much energy
would it take to compress say 1kg or 100kg (1 tonne) of H2 to 350/700
bar ?

Given the phase change additional to LH2, I shudder to think about that
one.

Graham

For adiabatic compression: W = (n/(n-1) * Po*Vo * [(P1/Po) ^ ((n-1)/n)) -
1].

Where, W = Work in J/kg; Po = initial pressure in N/M^2; P1 = final
pressure in N/M^2; Vo = initial specific volume in M^3/kg; n = ratio of
specific heats.

For H2, n = 1.41; Vo = 11.11 M^3/kg

To compress H2 to 800Bar, requires approx. 23 MJ/kg.

Have fun!

That "law" fails at higher pressures.
You store a lot less than you think.

--
Many thanks,

Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss:http://www.tinaja.com/whtnu.xml email: d...@xxxxxxxxxx

Please visit my GURU's LAIR web site athttp://www.tinaja.com

Why not use it as is, rather than storing H2?

What good is stored energy that's not all that affordable or much less
space efficient. As lord all-knowing Mook says, you might as well use
liquid/compressed air.

- Brad Guth
.

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