[Stoves] Distillation and oxidation Re: Understanding TLUDs, MPF and more. (was Re: Bangladesh TLUD )

[Andrew Heggie]

On 4 January 2018 at 01:10, Paul Anderson <psanders at ilstu.edu> wrote:

> Oxidation during pyrolysis:
>
> Not a reference, but a statement and question:   When a carbohydrate
> molecule (containing O and H and C) is broken apart by heat (which is the
> process of pyrolysis), what happens inside the molecule is not totally
> understood.  Is it not possible that a carbon atom that is linked to an
> oxygen atom (and to many other atoms) could not be shedding the other atoms
> and the C + O are never separated?   That would result in a molecule of CO
> that is NOT from the combination of C with O, and therefore the C was not
> oxidized.   The C was already with the O.
>
> The "atomic scientists" can discuss that possibility.   I leave it as CO
> being present as a result of pyrolysis, and not necessarily because some
> "free standing" "liberated" atom of O was then joined with an atom of C.

Paul  did you get any further with this?

I suspect you narrowed the field a bit by qualifying who should reply.

There are two separate points here

1) It is probably known which bonds are broken and new ones remade
during pyrolysis as nuclear magnetic resonance enables a lab to
estimate types and  the frequency of occurrence of different bonds,
each bond C-C C=C C-O -OH re radiates the energy at different
frequencies. More importantly is whether there is enough energy is
available to break the bond. and this leads to point 2

2) Crispin seems to be saying that, given knowledge of all the bonds
in a piece of wood, there is net energy available  to reform all the
hydrogen with the oxygen in the wood  to give water and carbon as the
outputs? Have I got that right Crispin?

It may be so but for the purposes of burning fuel in cookstoves we are
just going to have to supply air and enough initial heat for oxygen
molecules to dissociate and react with the fuel.

Andrew