[Terrapreta] Strong warning against "simple" charcoal kilns

[Kurt Treutlein]

Sean K. Barry wrote:

You keep carrying on about producer gas. What producer gas?? Volke's 
simple two drum kiln consists of an inner drum, packed with dry wood 
blocks, which is inverted in an outer drum. The bottom rim seals, more 
or less against the bottom of the outer drum. The outer drum has a row 
of quite sizable holes around the bottom of the drum wall for air 
ingress. The space between the drums is filled with the primary heating 
fuel. This is set on fire and burns down, heating the contents in the 
inner drum to pyrolysis temps. The so produced pyrolysis gases, mainly 
vapourised tars and other lighter fractions plus some gases, CH4 if 
hardwood is used in the inner drum) escape between the inner drum rim 
and the outer drum bottom. They ignite in the air coming through the 
holes in the side of the outer drum and burn up. This provides further 
heat to keep the pyrolysis going in the inner drum. If the amount of 
primary fuel between the inner and outer drum is apportioned properly, 
then there will never be any hot charcoal there to bring about the 
production of producer gas. All the pyrolysis gases will simply burn 
away to CO2 and H2O. There should never be any significant amount of air 
entering the inner drum. It WILL be necessary to properly size the 
airholes in the outer drum wall to ensure a clean burn.
>  Hi Kurt,
>
>  You are wrong.  You assume that ALL of the pyrolysis gases are
>  burned.  You do not know this and you cannot state it as an
>  observation made by anyone else, either.

And neither can you state the reverse

>  Correct me if I'm wrong, but there is 10 times as much CO and 10
>  times as much H2 in "producer gas", than there is Methane-CH4.
>  Correct me, also, if the heat of formation of CH4 is not higher than
>  for that of either H2 or CO.  Ergo, CO and H2 will burn first is and
>  use up the oxygen first, is my assessment.

There is no producer gas, so yes, you are wrong

>  They will use up the oxygen available at the bottom of the outer
>  barrel, and the Methane-CH4 will eject, unburned from the top of that
>  "charcoal-in-a-barrel" retort.

Perhaps you should actually study the pictures Volker provided.

>
>  Regards,
>
>  SKB

and the same to you

Kurt