Dear Doug, biomass is formed by the process of photosynthesis. Burning biomass is considered to be carbon neutral, because the carbon dioxide produced in this process was originally already in the atmosphere before it got sequestered in plants by photosynthesis. After being released into the atmosphere by burning, it would be sequestered again in plants by photosynthesis. Therefore, the carbon dioxide added to the atmosphere is zero. if any of the biomass is converted into char and buried into the soil, it creates a negative carbon dioxide balance, irrespective of the proportion of char going into the soil. Yours A.D.Karve
*** Dr. A.D. Karve Chairman, Samuchit Enviro Tech Pvt Ltd (www.samuchit.com) Trustee & Founder President, Appropriate Rural Technology Institute (ARTI) On Wed, Apr 20, 2016 at 11:24 AM, Doug Williams <[email protected]> wrote: > Hi Mark, > > You ask: > > After gasification, approximately 5% of the woody biomass remains a > biochar > > which sequesters carbon, hence a 'carbon negative' claim can be made. > > Qualify which type of gasification, because 5% would only apply to a > high performance gas making system. If however it was a pyrolysing char > making system, about 1/3rd of the fuel weight would be char, but two > thirds would be consumed by combustion to become a CO2 emission. So not > honestly carbon negative in my opinion (other than replacing fossil > carbon). Restoration of the environmental CO2 balance would be a tricky > calculation. > > > Alternatively, if the woody waste is left to rot in situ, the carbon > > sequestration is 0% (all carbon is released/transformed into CO2 and > other > > gasses). > > That fits the normal explanations, we all go back to CO2 and CH4 if > left to rot(:-) > > > True? > > Truth can be very elastic sided when claims are made about > gasification, so take care to confirm all calculations regarding the > process in question.There is a lot of attention paid to carbon credits > as an intensive to cheat in the Souther Hemisphere, and one should be > careful if included in any proposals. > > Doug Williams, > Fluidyne. > > _______________________________________________ > Gasification mailing list > > to Send a Message to the list, use the email address > [email protected] > > to UNSUBSCRIBE or Change your List Settings use the web page > > http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org > > for more Gasifiers, News and Information see our web site: > http://gasifiers.bioenergylists.org/ >
_______________________________________________ Gasification mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org for more Gasifiers, News and Information see our web site: http://gasifiers.bioenergylists.org/
