[Terrapreta] fast vs slow pyrolysis

[Douglas Clayton]

Tom,

This is dangerous.  I am engaging in idle speculation here.  Please ,  
no one take this as the truth.  It would be better to read some  
scientific papers.  But, I think, lower temperatures produce more  
acetic charcoal.  I know completely combusted wood (ash) is very  
alkaline.

Sorry to be so ignorant.  does fast vs slow refer to anything beyond  
temperature?

In Danny Day's powerpoints on the Eprida site it looks like he is  
suggesting slightly less than 400C as a best pyrolysis temp, ballancing  
C sequestration liking less and microbial life liking char produced at  
higher temps. (I'm having some difficulty looking at this PowerPoint  
stuff because I don't have the right software so I'm seeing all the  
layers at once.  If anyone has a suggestion for a Mac user who doesn't  
want to buy Microsoft Word, I'd like to hear it.  icWord didn't work.)

This seems to contradict my understanding that the charcoal may greatly  
increase C in the soil by triggering/catalyzing the large increase in  
microbial life and the creation of glomalin associated with fungi. (it  
is my understanding that the charcoal-glomalin connection is unproven  
theory).

I understood Johannes Lehmann to be speculating 450C as a good temp.   
Maybe.

I'm going back to the reading now.

Doug Clayton
50 Bullard Rd
Jaffrey, NH  03452
603-532-7321


On Feb 23, 2007, at 8:57 PM, Tom Miles wrote:

>
> Doug,
>  
> I’m curious about the reason between the fast pyrolysis char vs slow  
> pyrolysis char. I’d like to see the research or the anecdotal  
> experience that supports this. Char can have different properties for  
> many reasons. It is probably in the Lehmann papers that we have linked  
> to the site.
>  
> Tom
>  
>  
>
> From: terrapreta-bounces at bioenergylists.org  
> [mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of Douglas  
> Clayton
> Sent: Thursday, February 22, 2007 8:21 PM
> To: Jeff Davis
> Cc: terrapreta at bioenergylists.org
> Subject: Re: [Terrapreta] Terra Preta & Pigs
>  
>
> I spoke with Dr. Johannes Lehmann this morning and received the clear  
> message from him that it was a mistake to go fooling around  
> willy-nilly with charcoal at this time. Not that it is dangerous but  
> just that it is hard to learn anything definative. The science isn't  
> there yet to know what we are doing. This was a great disappointment  
> to me but I understand where he is coming from.
>
>  Dr. Lehman indicated that the temperature at which the charcoal is  
> produced is critical, the material being charred and the end use, the  
> soil type and conditions and the crop being grown are variables about  
> which we can not yet, say what is appropriate. Not knowing the source  
> material means something may work one time but not the next. He  
> indicated that it is definitely not a panacea and applying charcoal  
> can, in some circumstances, do harm to soils and crops.
>
>  Never the less, I plan to experiment a little bit in the garden this  
> summer myself!
>
>  How do we check the pH of the charcoal we purchase or produce?
>
>  Douglas Clayton
> 50 Bullard Road
> Jaffrey, NH  03452
>  H. 603-532-7321
>  W. 603-532-1120
>  Fax. 603-532-4581
>
>  On Feb 22, 2007, at 10:27 PM, Jeff Davis wrote:
> wrote:
> Jeff, charcoal is used for human consumption for certain conditions
>  including indigestion and some poisonings. I think that some of it in  
> the
>  soil would
>  be not so bad for the pigs.
>
>
>  Maybe the pigs would be helpful to the Terra Preta. They rot, eat  
> soil and
>  produce manure.
>
>
>  Jeff
>
>
>
>  --
>  Jeff Davis
>
>  Some where 20 miles south of Lake Erie, USA
>
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>


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