[Terrapreta] Farm/compost biochar

[Dick Gallien]

Hi Robert and Max,

It would seem that top lit would not be the best, for the reason you
mention, plus smoke and more ash than char.  Some of you must've filled a 55
gal. drum with wood and top lit it--probably shot a few holes in the base
with the .22 to keep it going--just to check the ash to char.  Will do it
tomorrow.

Am afraid that even when air tight and bottom lit, it could/would get too
hot for the steel.  Ken Calvert NZ suggested a good seal for the lid is a
lip around the edge of the tank filled with sand, that the edge of the lid
sets down in.   Am leaning toward the indirect method, with some tank or box
from the junk yard, that will be part of the 4' X 4' door we'll cut at the
base of the tank, so it'll slide into the tank and be removed for cleaning
out the char.  Half charred larger pieces will be a problem.   This gets
down to the mechanics of  where to take off the producer gas and return some
to the door burner.

Was on a roll this evening--would take about 100 bunker blocks at $35 @ to
make a 10' H X 10' wide 50' long  bunker into a slope on the edge of the
very large pile of wet biomass.  Have some 11' dia fuel tanks cut in  half
length wise, 18' that could cover the bunker, then seal the cover and sides
with wet biomass.  The Trojan loader has an 8' wide bucket and is 10' high,
so can smash brush in and bring the char out and the size of uncharred
pieces wont be a problem. Then the mechanical problem of a crude, removable,
top loading burner, probably made from part of a fuel tank that will seal
and heat the end----and how to bring some of the producer gas to that
burner?  Nice part is I can do most of this myself.  Ain't life interesting.
Thanks, Dick

On Wed, Jun 4, 2008 at 11:45 AM, Robert Klein <arclein at yahoo.com> wrote:

> hi Dick
>
> Your material is not packed enough to work well from the top.  A burn on
> the bottom will be gravity fed.  And there has to be way to use the burning
> gases to heat the fuel itself.  It may be that you simply ensure enough air
> to complete the burn inside the stack.  That is why an earthen kiln as
> traditionally used works fine while only losing thirty percent of
> production.
>
> Maybe you measure stack gas temperature and damp it down if it is rising.
> Blending the exit gas with the air intake will also help.
>
> I continue to appreciate traditional earthen kiln methods.  Their only flaw
> is the need for a lot of labor.
>
> You are also demonstrating for everyone, the reason it was impractical to
> produce terra preta from 100% wood on a volume basis.
>
> regards
>
> arclein
>
> ----- Original Message ----
> From: Dick Gallien <dickgallien at gmail.com>
> To: terra pretta group <terrapreta at bioenergylists.org>
> Sent: Wednesday, June 4, 2008 5:41:14 AM
> Subject: Re: [Terrapreta] Farm/compost biochar
>
> Hi Max,
> My wife is a  ten quid Pom from Redcliffe.  Left Mother England at 4.
>
> Now we're narrowing it down.  On the internal fire, Kevin suggested top
> lit, with wvo, of which I have over 2,000 gallons plus waxed boxes, spread
> on top to start it.   What would be the  pros and cons of top lit vs. bottom
> lit in producing char?  In both cases the gas would be flared off, which
> would go on for days.  Could that gas eventually be run through a turbo?
> As the first experiment, what if it was top lit without the lid, adjusting
> air intake from the base.  Because of the 10' dia., suppose it could create
> air flows without any bottom air.  Can start small, see how the heat is
> affecting the tank.  There is only the 6" space between the 10 and 11' dia
> tanks and the roof of the steel bldging. Eventually that has to be
> insulated, to protect the bldging.  We'll find out right away what damage
> the heat does to the roof.  Thoughts on 6" of wide open air flow vs. 6" of
> perlite?
>
> Thanks for your input.  Later, Dick
>
>
> On Wed, Jun 4, 2008 at 4:26 AM, MFH <mfh01 at bigpond.net.au> wrote:
>
>>  Dick
>>
>>
>>
>> Thanks for photos of tanks. Serious stuff indeed.
>>
>>
>>
>> Basically you have two options: (a) making char the traditional way with
>> an initial fire inside the container and (b) using an external fire.
>>
>>
>>
>> Given the size of your tanks and limited cash I'd suggest that the
>> internal method will be the most cost-effective and simplest to implement.
>> It won't give gas for other purposes but it will produce copious volumes of
>> char. For an external heat system for example, there needs to be reasonable
>> insulation of the tank. That alone will be logistically difficult and
>> expensive.
>>
>>
>>
>> Perhaps other experimenters on list have alternative suggestions. If we
>> can arrive at the best technique then we can look at the mechanics.
>>
>>
>>
>> Max H
>>
>>
>>
>>
>>
>>
>>  ------------------------------
>>
>> *From:* terrapreta-bounces at bioenergylists.org [mailto:
>> terrapreta-bounces at bioenergylists.org] *On Behalf Of *Dick Gallien
>> *Sent:* Wednesday, 4 June 2008 12:38 PM
>> *To:* terra pretta group
>> *Subject:* Re: [Terrapreta] Farm/compost biochar
>>
>>
>>
>> Hi Robert,
>>
>>
>> I agree, we're not picky about the finished product.  Have a few charred
>> pieces in the field from what I put on with the 425 bu. spreader last week,
>> but in a garden that I don't have to till, that is no problem.  If a chunk
>> is too large to fit out the 4' X 4' door, we can just leave it in for the
>> next batch or two.
>>
>> As you say,  we're down to that simple system we're fishing for.  Have any
>> of you seen, heard or read about a simple retort system on even a small
>> vertical tank?  How is the excess gas separated and vented from that needed
>> to maintain the charring temp.?
>> Thanks,  Dick
>>
>>
>>
>>
>> On Tue, Jun 3, 2008 at 4:57 PM, Robert Klein <arclein at yahoo.com> wrote:
>>
>> Hi Dick
>>
>> I certainly can appreciate the desire to avoid processing the materials.
>> You also have a large enough tank to give it a good shot.
>>
>> The reason for thinking about packing is that it will control the
>> uniformity of the end product.  However, it seems that we will end up with a
>> tank full of oddly sorted and sized material.
>>
>> The problem as I see it is that the larger chunks will simply not be
>> processed fully.  but that may also not be too much of a concern.  Screening
>> will; separate fines, charcoal fuel and the larger bits.  The larger bits
>> can be thrown back into the kiln as a starter fuel.
>>
>> The difficulty centers around how do we keep the temperature under 600
>> degrees (actually around 400) and then use the production gas to make heat
>> that can be fed back into the kiln and how do you exhaust the spent
>> combustion gases.
>>
>> arclein
>>
>> The tank really allows us avoid worrying about packing, unlike traditional
>> wood kilns.
>>
>>
>> Dick Gallien
>> 22501 East Burns Valley Road
>> Winona MN 55987
>> dickgallien at gmail.com [507]454-3126
>> www.thewinonafarm.com
>>
>
>
>
> --
> Dick Gallien
> 22501 East Burns Valley Road
> Winona MN 55987
> dickgallien at gmail.com [507]454-3126
> www.thewinonafarm.com
>
>


-- 
Dick Gallien
22501 East Burns Valley Road
Winona MN 55987
dickgallien at gmail.com [507]454-3126
www.thewinonafarm.com
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