In article , Frithiof Andreas Jensen
wrote:

"Ed Huntress" wrote in message
...

Unfortunately, producing the hydrogen is not that efficient. No free
lunch,
once again.


It is fairly efficient cracking a hydrocarbon to produce H2 - improving the
efficiency of the use of fossil fuel by about 100 % also has utility.

I think the main drawback there is that the H2 does not have most of the
available energy of a hydrocarbon.

Let me pick two - propane out of a hat, and methane it has more hydrogen
as a percentage of content than any other hydrocarbon.

Heats of combustion (to CO2 and water vapor, hope I got this right):

Propane: 486.6 kcal/mole H2 from propane: 231.3 kcal for 4 moles

Methane: 192.2 kcal/mole H2 from methane: 115.7 kcal/mole
(60%)

Not counting that it takes some energy to crack these to get the
hydrogen. Looks like you have to use the carbon for something however.

Messing around with pure hydrogen is silly and represents the typical
eco-loon thinking I.M.O - there is a vast infrastructure for handling
hydrogen when wrapped in a liquid but there is none for pure H2.

My impression was that main use of this was for when electricity is
mainly generated by means other than burning fuels. The alternative -
could largely win out - is rechargeable batteries.

- Don Klipstein )