[Terrapreta] TP Benefits

[Sean K. Barry]

Hi Mark,

There are no or very little termites in the temperate north woods of Minnesota where I live.  I do not know how much biomass is digested by termites versus how much or where it decays, or versus how much or what would be used to make charcoal-for-soil.

The immediate release of Methane-CH4 from lots of badly done, simple pyrolysis in the semi-open air will have an immediate, profound, and long lived effect on an atmosphere in our environment.  Our environment is now very sensitive to taking more buildup of any GHGs (especially more potent Methane-CH4) and will continue to change, and possibly change radically as a result.

How much carbon is released to the atmosphere as CO2 from burning or Methane-CH4 released to the atmosphere from the digestive tracts of termites or cloven-hooved beasts is one of those quantity/quality issues to resolve. It is possible that current natural emissions of CH4 could be ignored if only temperate climate biomass or biomass that only decays (not eaten by termites) were used to make charcoal.  Then again, taking food from termites and cleanly pyroyzing it into charcoal-for-soil may be the best way to beat back rising GHG emissions into the atmosphere!  We should burn all termite infested trees, if termite releases are more than ~2-3% CH4 (volume CH4/volume of flatulence)?

Carbon yield in charcoal can easily be >90%.  Charcoal yield from total biomass (weight/weight) is ~25-40%, depending on pyrolysis method and feedstock.  Carbon yield from biomass (through pyrolysis) can be as high as ~60some% (weight/weight).  So ~10% of the original carbon in biomass can be released as Methane-CH4.  At 23 times more potent, releasing this Methane from the pyrolysis reactor, with the resulting 230% increase (+23 x 10%) in greenhouse warming potential beats out burying the remaining (~40-50%?) of the carbon and the benefit that could be had from putting all the charcoal into soil.  It is that simple.

Now, if termites release more than 10% of the carbon in the biomass they chew as Methane-CH4, then pyrolyze termite infested wood now.

Regards,

SKB

  ----- Original Message ----- 
  From: Mark Ludlow<mailto:mark at ludlow.com> 
  To: 'Sean K. Barry'<mailto:sean.barry at juno.com> ; 'Edward Someus'<mailto:edward at terrenum.net> ; 'Richard Haard'<mailto:richrd at nas.com> 
  Cc: terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org> ; tjones at nas.com<mailto:tjones at nas.com> ; friendsofthetrees at yahoo.com<mailto:friendsofthetrees at yahoo.com> ; anaturalresource at gmail.com<mailto:anaturalresource at gmail.com> ; hans at riseup.net<mailto:hans at riseup.net> 
  Sent: Monday, March 24, 2008 12:20 AM
  Subject: RE: [Terrapreta] Net Present Value and Net Future Value ofTPBenefits


  Hi Sean,

   

  We need to put this in perspective. If wood is left to termite digestion, the amount of CH4 released skyrockets. Complete combustion, in theory, essentially converts all of the cellulosic carbon (as well as the saccharides in the sap) to CO2. Smothered combustion (pyrolysis) has at least the potential to preserve 25-to-30% of the original carbon as immobilized carbon.

   

  If, as it is claimed, this carbon makes the soil more productive, then subsequent cycles of pyrolytic combustion should even be progressively more useful, as higher soil productivity would equate to higher photosynthetic conversion of atmospheric CO2.

   

  I doubt that the pre-Columbian farmers in Amazonia did much that was deliberate; a late burn, into the rainy season (of a rain forest), probably produced a fair amount of incomplete combustion or charring. Perhaps they saw enough of a difference in agricultural productivity to intentionally shift their methods toward the more labor-intensive char burning. We may never know. An immediate goal of NGOs in places like Amazonia and Indonesia, might be to encourage incomplete combustion in land-clearing efforts. There's at least the potential of some upside compared to the alternative method which leaves only ash. 

   

  Ideally, retort-based charring (fueled by pyrolysis gases) would address your concerns about CH4, but it's hard to imagine that retorts will replace slash burning anytime soon, on a large scale. Even here in the Northwest, slash burning is the norm although the number of Cat D-10s in the woods should provide other combustion opportunities.

   

  Mark

   

  From: terrapreta-bounces at bioenergylists.org [mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of Sean K. Barry
  Sent: Sunday, March 23, 2008 10:19 PM
  To: Edward Someus; Richard Haard
  Cc: terrapreta at bioenergylists.org; tjones at nas.com; friendsofthetrees at yahoo.com; anaturalresource at gmail.com; hans at riseup.net
  Subject: Re: [Terrapreta] Net Present Value and Net Future Value ofTPBenefits

   

  Hi Richard, et. al.

   

  Attempting pyrolysis in the "semi-open" to make some charcoal of biomass and complete combustion of biomass differ in an important way.  The limited oxygen in a pyrolysis reaction can promote the production and emission of Methane-CH4 (a significant and potent GHG), whereas in complete combustion without the limit on oxygen, the biomass fuel is reduced to ash and complete combustion products (CO2 and H2O), with very little or no Methane-CH4.

   

  With Methane-CH4 even at a mere 2-3% component (volume/volume) of the "producer gas", because of its potency as a GHG, releasing it will do more damage to the atmospheric concentration of GHGs and the GHG warming potential than the improvement that could be had by sequestering most of the remaining carbon from the biomass.  The damage from CH4 emissions can wipe out the advantage from sequestering the highest yield of charcoal (~30-40%) by weight.

   

  The implement that is used to make charcoal in situ CANNOT release Methane-CH4.  The process must use it or flare it at the very least.

   

  Regards,

   

  SKB

   

   

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

    From: Richard Haard<mailto:richrd at nas.com> 

    To: Edward Someus<mailto:edward at terrenum.net> 

    Cc: sean.barry at juno.com<mailto:sean.barry at juno.com> ; kchisholm at ca.inter.net<mailto:kchisholm at ca.inter.net> ; folke at holon.se<mailto:folke at holon.se> ; tjones at nas.com<mailto:tjones at nas.com> ; anaturalresource at gmail.com<mailto:anaturalresource at gmail.com> ; friendsofthetrees at yahoo.com<mailto:friendsofthetrees at yahoo.com> ; terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org> ; hans at riseup.net<mailto:hans at riseup.net> 

    Sent: Sunday, March 23, 2008 2:16 PM

    Subject: Re: [Terrapreta] Net Present Value and Net Future Value ofTPBenefits

     

    Edward - Are you comparing 'semi open, "simple" home made to industrial appliances or to burning of forest debris/ agricultural waste? It seems for the subsistence farmers of the humid tropics slash and char offers a reduction in net emissions even with simple methods so long as the biomass is carbonized, even partially. In addition, use of biomass as compost or letting decompose on ground will result in conversion of 100% to atmospheric form. The challenge is to design an implement  and distribute the appliance that can be economically used on a scale that is significant where biomass either cannot be transported or is not economic to do so. In urbanized air quality controlled  areas an air quality controlled implement is appropriate, but in rural areas where debris is burned anyway then low tech pyrolysis would result in a net permanent reduction of emissions.  

     

    Further, the use of an appliance that requires an investment and maintenance would be incentive to recover cash value of charcoal as fuel and at small scale as yet economic return from carbon buyback is not significant. This is what has me thinking that a low tech solution in or near the farmers field that results in a partial charred/compost-able product would yield a higher level of sequestration. 

     

    Please critique this viewpoint. For example, can you conclude charcoal produced in this manor has lesser value in agriculture than converting forest and agricultural debris to ash?

     

    Thank you 

     

    Rich H

     
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