[Terrapreta] Long term durability of Low Temp Chars

[Duane Pendergast]

Sean,

 

I'm guessing a bit, but suspect that the yield may partly depend on how much
of the energy to achieve the pyrolysis comes from the biomass itself. If an
external source of energy, say electrical heating, is employed the yield
might be increased.

 

I'm sure Michael Anton or Danny Day is much better qualified than I to
comment on this.

 

Sincerely,

 

Duane Pendergast

 

-----Original Message-----
From: terrapreta-bounces at bioenergylists.org
[mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of Sean K. Barry
Sent: May 17, 2007 9:10 AM
To: AJH
Cc: terrapreta
Subject: Re: [Terrapreta] Long term durability of Low Temp Chars

 

Hi AJH,

 

I've read, from work by Michael J. Antal, at the University of Hawaii, that
the maximum theoretical amount of carbon, which can be retained in charcoal,
after pyrolysis of biomass, is somewhere ~30-40% by weight of the feedstock
biomass.  Achieving that is difficult and usual yields are more likely
around 25% on a weight by weight basis charcoal/dry weight biomass
feedstock, with charcoal being ~93-95% carbon.  Michael is a member of this
list and he may be able to answer your questions better, so try to contact
him  (maybe he will see this post and respond to you directly?).

 

Regards,

 

SKB

----- Original Message ----- 

From: AJH <mailto:ajh at sylva.icuklive.co.uk>  

To: Sean K. <mailto:sean.barry at juno.com>  Barry 

Sent: Thursday, May 17, 2007 9:56 AM

Subject: Re: [Terrapreta] Long term durability of Low Temp Chars

 

On Tue, 15 May 2007 16:21:51 -0500, Sean K. Barry wrote:

>I don't think that it is doubted that anything less than a very high
percentage of the original charcoal matter that was put into the soil over
some thousands of years ago, is not still there.

Nor I, I'm fairly confident all the fixed carbon will be there still
but when the claim is made for carbon credits and there is ~18% of the
weight in carbon-oxy-hydrogen compounds how much weight of carbon is
sequestered?

AJH



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