Re: [biochar] First retort kiln, smoking like crazy [Discussion]

Dear Ted and all,

On 3/7/2016 3:59 PM, Ted White [biochar] wrote that he
did not get a good result when:


I burned the TLUD 55 gal
+ 30 gal exactly as in the video.

The video he followed was by Bob Wells:

The process used is virtually identical to that shown by Peter

Bob and Peter are the two principals in New England Biochar so it is
not surprising that they use the same method
I know both Bob and Peter very well and we are all certainly
friends.  Peter has heard from me a couple of years ago my comments
below, but I had not seen Bob’s video nor commented about it to him
before now.

Both videos show that the method can work, and Bob states that he
has done it successfully over a hundred times.   While not wanting
to “argue with success”, it is Ted’s unsuccessful experience that
prompts this message.

As Bob says in his video, there are many many ways and devices for
making biochar.   Certainly some will be better than others, and an
attitude of “it works for me” is quite acceptable.   Below is my

1.  Retorts for production of biochar have pros and cons that are
too numerous to discuss here.  Place a barrel (30 gal) inside a
large barrel (55 gal).  That is well and good.

BIOMASS IN THE INNER BARREL.   In a “standard” retort configuration,
the heat comes from a fire that is below the inner barrel, maybe
inside the larger barrel or maybe outside (and under) the larger
barrel.   There are many examples of this, including have a TLUD
unit UNDER the larger barrel, as shown by Doug Clayton and Hugh
(The height and weight of the unit can cause safety issues, so this
unit has not become common practice.)

3.  The problem with the Hirst-Wells configuration comes from using
BARREL.   This TLUD heat is created very high in relation to the
inner barrel that needs to be heated.   In fact, if operated as a
TLUD, most of the TLUD heat is created at the level of the secondary
air holes, with the flames going up the chimney, not to the sides of
the inner barrel.  As a result, the heating of the biomass in the
inner barrel is quite slow in consideration of the amount of biomass
being consumed.  Note that although the TLUD method produces char in
the area between the two barrels, that char is later consumed by the
rising flames coming from the gased from the retort, so there is no
“double making of char (retort and TLUD char)” in this case.

4.  So, why does it work so well for Bob Wells?    Success is
probably because he is using kiln-dried off-cut wood from furniture
factories as his biomass.   He even reports that the vertical boards
between the two barrels are not even consumed by TLUD pyrolysis
before the combustible off-gas is coming from within the retort.

I could be incorrect.   We are all still learning.   But I have seen
replications of the Hirst-Wells technique failing to work in other
situations, resulting in incomplete pyrolysis of the biomass in the
retort barrel.   Some people are investing their time and money on a
method that does not have a solid foundation of science, that is,
put the heat under a retort and not on top or downward along the
sidewalls.  I would not recommend this method.


Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD
Skype:   paultlud    Phone: +1-309-452-7072
On 3/8/2016 5:02 AM, Geoff Thomas [biochar] wrote:


Has to be this one,

Good video, especially if you watch the 2nd
one, good work those guys are doing, very comprehensive in
their down home way, so pleasing to see this sort of local
but idealistic stuff happening in the USA, so different to
the politics.
Wondered if the Flame cap units would be
better to demonstrate but then again they had to lead over
to gasifying.
I must admit I have always found Tom’s little
Wood Gas Camp Stove to be the best demonstration of the
gasifying principle even though hard to demonstrate to a
larger group, because the fire front disappears, then the
gas comes and you can see it burning, – a real ‘Ahahh!’
moment, whereas theirs was mainly an aural message,
roaring chimney, but whatever, whatever works.
Thanks Ted.
Cheers, Geoff.


On 8 Mar 2016, at 2:34 pm, Paul Anderson
[biochar] <>



What is the video that was your guide?   (I
believe I know which one, but I will not


Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD
Skype:   paultlud    Phone: +1-309-452-7072
On 3/7/2016 3:59
PM, Ted White [biochar] wrote:


burned the TLUD 55 gal + 30 gal exactly
as in the video.

There’s paint on the inside
and outside of both barrels. Burnt paint
comes out the chimney.


On Mar 7, 2016, at
4:57 PM, [biochar] <>


Yeah, paint
is surely burning off, but
the smoke is coming out
the top of the stack. We
had some sprinkles here
for most of the morning,
so I’m thinking maybe the
wood was a bit damp?





Posted by: Geoff Thomas