Getting hydrogen from water.

xraydog

Writing a report on a future hydrogen economy. I'm doing a little side experiment with extracting hydrogen from water.

Any ideas on how one could get hydrogen gas from water without using electrolysis? Preferably, using as little electricity as possible. Or any other method of getting hydrogen that doesn't include water will be helpful.

Thanks.

Speleodot

http://www.ucc.ie/academic/chem/dolchem/html/elem/elem001.html

Manufacture
Pure hydrogen is manufactured industrially by the steam reforming of natural gas, and by the electrolysis Of water.
The manufacture of hydrogen on an industrial scale involves the reaction between steam and iron. Spongy iron from the reduction of spathic iron ore (ferrous carbonate) is heated to redness and steam passed over it.


3 Fe + 4 H2O ==> Fe3O4 + 4 H2

The hot ferrosoferric oxide, Fe3O4, is then reduced with water gas:

Fe2O4 + 4 H2 ==> 3 Fe + 4 H2O

Fe2O4 + 4CO ==> 3 Fe + 4 CO2 Water gas is made by passing steam over red hot carbon and it consists of a mixture of carbon monoxide and hydrogen, with a smaller amount of carbon dioxide:


bright-red
heat
C + H2O ==> CO + H2

dull-red
heat
C + 2 H2O ==> CO2 + 2 H2

blincoln

Part of the reason hydrogen is usable as a fuel is that you get a good amount of energy from turning it *into* water. There is no such thing as a free lunch, so that means that getting it back out of the water *consumes* a good amount of energy.

Hydrogen in the "hydrogen economy" is best thought of as a medium to store energy in, like a battery. E.g. you have a nuclear reactor which provides cheap energy to do the electrolysis or whatever, and the hydrogen is used to store potential energy for use in e.g. cars.

It's *not* a cheap fuel source on its own, like petrol/gasoline is currently. Maybe if you were on Jupiter, and could just scoop some out of the atmosphere, but not here on Earth.

NeoDragos

http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/HTML/ps_power.html

Search for OTEC. Pretty cool stuff if they can get some money to set up a ship to do it. Basically it uses the temperature offsets in the surface of certain parts of the ocean to generate power with the only bi products being ammonia, hydrogen, and distilled water.