[Stoves] Re Alexis Belonio article

[Crispin Pemberton-Pigott]

Dear David

Thanks for this:

H2O + energy + C => H2 + CO where the carbon
comes from the pyrolysized fuel.  This reaction
requires a very hot pyrolysis zone -- in excess
of 800º C, some claim in excess of 1000º C!

I have been trying to work out whether this actually takes place in a small
stove or not.  It would have the effect of cleaning up free carbon if there
were any.  There is a vaguely claim by some ethanol stove makers that they
are burning water in their mix.

If the energy requirement  is 15,975 Joules per gm of steam to break it
apart into 2H+O, it means that energy has to be absorbed as heat, right?
What would the temperature be if this happened?  I presume the
disintegration would take place as follows:

1) the temperature rises until the added energy reached 463 kJoules (per
mole) and one of the hydrogens would break away.

2) the temperature would drop,

3) it would repeat this leaving the oxygen free

There might be other intemediary steps involving Carbon that worked at a
lower temperature which seems more likely.

But....if this is the path, for 1 gm of steam to absorb 25700 J of energy
and having a specific heat of 2.0276 J/gm it would have to reach 12,600
degrees before separating.

To me, it indicates there are steps involving lower temperature reactions
that might 'eat away' at the water molecule converting it to things that in
the end, result in water again.  But at no time would there be free hydrogen
and oxygen.  I am still waiting to see a realistic explanation of how this
happens, if indeed it does.

Thanks
Crispin