On Tue, 30 Dec 2003, Terry Harper wrote:

"Steve Firth" wrote in message
...

The trouble with hydrogen is that it is manufactured from hydrocarbons,
not by electrolysis of water. Thus using hydrogen as a fuel actually
increases CO2 emissions compared to burning those hydrocarbons in the
engine.

There is another route, used to produce hydrogen for barrage balloons
during WW2. This involves having a heated bed of Iron over which steam
is passed, and the steam is reduced to hydrogen by the iron. Of course,
energy is needed to preheat the iron and to produce the steam. Not to
mention to reduce the iron ore to iron in the first place.

Or, in a closed system, to reduce the iron oxide produced back to iron.

Ultimately, it all comes down to where you're going to get the energy
from; hydrogen is a fundamentally synthetic fuel, so you need to supply
electricity, hydrocarbons or light (if you're a photosynthesist) to make
it [1]. IMHO, the only practical carbon-neutral approach would be to use
nuclear electricity; i doubt that photosynthesis or renewable power plants
would be able to supply enough power.

tom

[1] Unless, of course, you're going to build a Bussard ramscoop and just
collect it in outer space. Ken may be a nutcase and/or visionary, but i
doubt even LT are seriously considering that .

--
or are they poststructuralist terrorists? perhaps we shall never truly know.