[Terrapreta] Bio-Char Sequestration in Terrestrial Ecosystems-- A Review

[Tom Miles]

Brian,
 
If I follow your math 1 ton of biomass can capture 3536 lb of CO2 or
3536/2200 = 1.6 tonnes of CO2 credit. At current Chicago Climate Exchange
prices of about $3.50/tonne that's $5.60/ton of biomass. 
 
If we use crop residues we might remove, carbonize, and return 2 tons/acre.
So that's 2 x $5.625 or $11.25/acre in CO2 credits.
 
It is likely that it would cost $80/ton of residue to harvest, process and
replace the carbon. So there is a net cost of residue processing of
($80.00-$5.625) $74.375/ton or $149/acre that would have to be offset by
growth enhancement.    
 
The nutrient value of that 2 tons per acre at today's oil prices is probably
about $60/acre. If we carbonize the residue we'll lose the nitrogen but
retain the P and K. So we'd still be looking for an extra $149/acre from
growth enhancement. It seems to me that the growth enhancement will require
higher application rates than the 1 ton of char residue that we returned
from a single harvest.  
 
If we used a biomass residue from an external source that would be paid for
by other values, e.g. wastewater sludge, then we would probably still pay
for the carbon. What application rates and costs would be typical? What is
the incentive for the farmer?
 
Are these the kinds of concepts that you are including in you model?
 
Tom      
 
  

  _____  

From: terrapreta-bounces at bioenergylists.org
[mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of Brian Hans
Sent: Saturday, February 10, 2007 3:18 PM
To: terrapreta at bioenergylists.org
Subject: Re: [Terrapreta] Bio-Char Sequestration in Terrestrial Ecosystems--
A Review


The beauty of char is that its a fixed carbon sink. once fixed carbon
becomes char, it pretty much stays in that form until burned. char and terra
preta is a way to verify that indeed carbon sequestering is taking place. 
 
terra preta could be paid for by carbon credits. its goes like this;
1 ton of 50% carbon weight biomass gets turned into 1000lbs of char. 1000lbs
of char / .2828 (molecular weight of C in CO2) = 3536lbs of CO2 out of the
air. 
the farmer also get friability and increased growth from terra preta so its
also a benefit to the farmer. by combining carbon credits on 3536lbs of CO2
and the farmer paying for the benefit that is terra preta, there is a very
crude economic model. imagine a system whereas we bring in biomass, bleed
off all the important aspects of the biomass, C-H energy and Nutrients, and
are left with a very dense form of char that is land top dressed. 
 
I know Johannes and work specifically on char. this 'could' work if the
desire to remove CO2 from the ATM whilst getting a benefit from that CO2 is
appreciated. the time is not ripe but its getting there...
 
Brian Hans
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