[Terrapreta] Clarification about "simple" charcoal devices

[Duane Pendergast]

To supplement Lorenzo’s third paragraph re efficiency of char production, I
wonder if terra preta experts would care to comment on the share of
non-charred biomass feedstock  that might be needed to feed the living
organisms said by some to be needed for the formation of terra preta?

 

That seems another aspect of making terra preta production as efficient as
possible.

 

Duane

 

 

-----Original Message-----
From: terrapreta-bounces at bioenergylists.org
[mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of Laurens
Rademakers
Sent: April 30, 2008 7:56 AM
To: terrapreta at bioenergylists.org
Subject: [Terrapreta] Clarification about "simple" charcoal devices

 

Günther, Kevin, Lou, Sean and the others,

 

It seems like there has been a misunderstanding about the short "warning" I
made against simple charcoal kilns. I didn't intend to downplay anyone's
efforts to produce charcoal this way. 

 

I made the warning because to me biochar / terra preta is still tied to a
very particular context: that of the tropics, close to forests and
carbon-rich ecosystems, the destruction of which can be limited by biochar.

 

And it is in this context that care must be taken to make the system as
efficient as possible. Because your initial biomass feedstock in this
environment will often be wood from secondary regrown forest, it is
important to make the most of it, else you do not alter the "slash-and-burn"
cycle enough and thus your crucial added benefit - that of reducing
deforestation - can get lost.

 

Efficient does not necessarily mean "large". One of the Biochar Fund's goals
is precisely to develop a village-scale plant that uses the syngas for power
production (capacity smaller than 20kW), and use it in this specific
context.

 

Small kilns or retorts made for use by individuals in other (agroecological)
contexts might be quite interesting, provided they don't emit too much
methane. So I wasn't warning against this at all. 

 

Apologies for any misunderstandings.

 

Regards,

Lorenzo

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