[Terrapreta] Farm/compost biochar

[MFH]

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 

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