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<DIV>Karve,</DIV>
<DIV>I agree, fundamentally. The way I see it is that there are a
few carbon cycles that are happening on this third rock. And its important to
keep the distinction between them. for simplicity's sake lets just look at
two of the cycles and call them the long cycle and the short cycle. The
long cycle locks up carbon and traps it within the earth n the form of
hydrocarbons, and through the billions of years carbon cycles from earth to air,
and and back again. Then there is the short cycle, in which the carbon is
not trapped underground in grand quantities for grand periods of time.
This short cycle it locks up carbon within the biomass on the surface of the
earth for short periods of time. I pose this question... what is the
average length of time carbon is trapped in biomass. On the west coast in
the US carbon can be trapped for thousands of years in the wood of a once great
temperate rain forest. In the Midwest- not so much more like an annual
event. I think it is important to understand the lag time involved, the effect
of burning something that will grow again in one year, is far different from
burning something that will take a thousand years to regrow. A year from
now one act would be nearly carbon neutral, whereas the other would be 999 years
not so carbon neutral. Consider this to be a “carbon lag time”.
While this “lag” is in effect there is more carbon in the air than there should
be... and that is what the real concern is all about. </DIV>
<DIV> Burning biomass may induce a portion of the carbon into the
long cycle, and burning fossil fuels injects nearly all carbon from the long
cycle into the short cycle. By burning fossil fuels we are short
circuiting the long cycle and end up with more carbon in the air than should be
– today. Also by burning biomass we short circuit the short cycle and end
up with more carbon in the air than should be - today.</DIV>
<DIV> I think its safe to say that we collectively agree that interfering
with the long cycle like we have is bad. The question I pose is
this. By how many years is it acceptable to short circuit the short
cycle?</DIV>
<DIV>Luke Gardner</DIV>
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<DIV style="font-color: black"><B>From:</B> <A title=adkarve@gmail.com
href="mailto:adkarve@gmail.com">Anand Karve</A> </DIV>
<DIV><B>Sent:</B> Wednesday, April 20, 2016 1:43 AM</DIV>
<DIV><B>To:</B> <A title=gasification@lists.bioenergylists.org
href="mailto:gasification@lists.bioenergylists.org">Discussion of biomass
pyrolysis and gasification</A> </DIV>
<DIV><B>Subject:</B> Re: [Gasification] Biochar - Carbon
Negative?</DIV></DIV></DIV>
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<DIV dir=ltr>Dear Doug,
<DIV>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.</DIV>
<DIV>Yours</DIV>
<DIV>A.D.Karve</DIV></DIV>
<DIV class=gmail_extra>
<DIV> </DIV>
<DIV>
<DIV class=gmail_signature>***<BR>Dr. A.D. Karve<BR><BR>Chairman, Samuchit
Enviro Tech Pvt Ltd (<A href="http://www.samuchit.com"
target=_blank>www.samuchit.com</A>)<BR><BR>Trustee & Founder President,
Appropriate Rural Technology Institute (ARTI)<BR></DIV></DIV>
<DIV> </DIV>
<DIV class=gmail_quote>On Wed, Apr 20, 2016 at 11:24 AM, Doug Williams <SPAN
dir=ltr><<A href="mailto:doug.williams.nz@gmail.com"
target=_blank>doug.williams.nz@gmail.com</A>></SPAN> wrote:<BR>
<BLOCKQUOTE class=gmail_quote
style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">Hi
Mark,<BR><BR>You ask:<BR><SPAN>> After gasification, approximately 5% of
the woody biomass remains a biochar<BR>> which sequesters carbon, hence a
'carbon negative' claim can be made.<BR><BR></SPAN>Qualify which type of
gasification, because 5% would only apply to a<BR>high performance gas making
system. If however it was a pyrolysing char<BR>making system, about 1/3rd of
the fuel weight would be char, but two<BR>thirds would be consumed by
combustion to become a CO2 emission. So not<BR>honestly carbon negative in my
opinion (other than replacing fossil<BR>carbon). Restoration of the
environmental CO2 balance would be a tricky<BR>calculation.<BR><SPAN><BR>>
Alternatively, if the woody waste is left to rot in situ, the carbon<BR>>
sequestration is 0% (all carbon is released/transformed into CO2 and
other<BR>> gasses).<BR><BR></SPAN>That fits the normal explanations, we all
go back to CO2 and CH4 if<BR>left to rot(:-)<BR><BR>> True?<BR><BR>Truth
can be very elastic sided when claims are made about<BR>gasification, so take
care to confirm all calculations regarding the<BR>process in question.There is
a lot of attention paid to carbon credits<BR>as an intensive to cheat in the
Souther Hemisphere, and one should be<BR>careful if included in any
proposals.<BR><SPAN class=HOEnZb><FONT color=#888888><BR>Doug
Williams,<BR>Fluidyne.<BR></FONT></SPAN>
<DIV class=HOEnZb>
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