Replies to post #579 on EXIM Internet Group, Inc (fka EXGN)

[chipotle_pickle]

Propane vs H2 is liquids vs solids.

A gallon of propane is a pressurized liquid gallon. See:
http://www.eia.doe.gov/kids/non-renewable/propane.html

Sorry for the "energy ant", but I've had no coffee yet and the doe.gov/kids/ pages were my reading level.

If everyone used metric, this wouldn't take so many conversion factors.
1 cuft = 7.5 gallons
1 gal liquid propane = 270 gal vapor at stp (room temp and pressure)

So 1 gal propane liquid = 36 cuft propane at stp

So the equivalent cost for the propane is 4.5 cents per cuft.

So if H2 and propane packed the same punch, that would make the H2 at 6 cents per cuft only a little (30%) more expensive than the propane. But propane packs a lot more punch.
heat of combustion of propane = 2200 kJ/mol
Heat of combustion of hydrogen = 285kJ/mole

The propane has 7.7X the energy of hydrogen per mole, and so per cuft at stp. So you need 46.2 cents worth of HERI Hydrogen to compare to 4.5 cents worth of propane.

This is pretty much the same as what we came up with when we went through the electrolysis comparison. If you want to compare to other methods of getting Hydrogen, this is 5X as expensive, to other methods of getting energy, 10X.