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<DIV><FONT size=2 face=Arial>Dean,</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>I am sorry, I failed to communicate clearly.
The primary air is continuous but it is continuously used up by part
of the continuous supply of wood gas before any air reaches the majority of
solid fuel, and so most of the fuel is heated without air. If air was
present here, then there would be more ash in the char. My thought is that
you are correct about gasification, but that gasification is a more general term
which includes several processes including dehydration, pyrolysis and
combustion.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Concerning the question about pyrolysis in a rocket
stove. I believe that wood gas is produced by pyrolysis. The
presence of oxygen burns the wood gas immediately after pyrolysis rather than
later like in a TLUD. In any fire, the wood does not burn, but rather the
wood gas produced by the heat is what burns. Yes, pyrolysis is present in
a rocket stove or any other wood fire.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>My responses may not
be completely right, but I have read your questions several times,
each time trying to come closer to understanding your intent. I have
attempted to respond to your questions rather than wander into other
related topics with statements that do not actually address your
question. I very much appreciate this when others respond to my questions,
and I feel that actually addressing the question is an act of
respect.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Kirk</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=deankstill@gmail.com href="mailto:deankstill@gmail.com">Dean
Still</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=stoves@lists.bioenergylists.org
href="mailto:stoves@lists.bioenergylists.org">Discussion of biomass cooking
stoves</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, May 16, 2015 10:07
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [Stoves] Pyrolysis: No
Air?</DIV>
<DIV><BR></DIV>
<DIV dir=ltr>Kirk,
<DIV><BR></DIV>
<DIV>That's very interesting! Thanks! </DIV>
<DIV><FONT size=2 face=Arial></FONT><BR></DIV>
<DIV>You say:</DIV>
<DIV><BR></DIV>
<DIV><SPAN style="FONT-FAMILY: Arial">"The small amount of added
air supports the combustion of a small amount of the gas to produce heat,
but that air is soon used up and most of the fuel pyrolyzes without added
air."</SPAN></DIV>
<DIV><SPAN style="FONT-FAMILY: Arial"><BR></SPAN></DIV>
<DIV><FONT face=Arial>I experience that a constant supply of air is needed to
keep the TLUD going. Without added air I see the gas making eventually stop so
I've wondered if the word gasification is a better descriptor. I agree that it
is a small amount of primary air which, if too much, makes too much gas and
then produces visible smoke since the mixing/time can't handle the overly rich
mixture. </FONT></DIV>
<DIV><FONT face=Arial><BR></FONT></DIV>
<DIV><FONT face=Arial>Too little primary air and the reactions stop?
You experience that no primary air is needed to continue the
reactions?</FONT></DIV>
<DIV><FONT face=Arial><BR></FONT></DIV>
<DIV><FONT face=Arial>What about a Rocket or an open fire? No pyrolysis?
Always has oxygen?</FONT></DIV>
<DIV><FONT face=Arial><BR></FONT></DIV>
<DIV><FONT face=Arial>Best,</FONT></DIV>
<DIV><FONT face=Arial><BR></FONT></DIV>
<DIV><FONT face=Arial>Dean<BR></FONT>
<DIV class=gmail_extra><BR>
<DIV class=gmail_quote>On Sat, May 16, 2015 at 8:34 PM, kgharris <SPAN
dir=ltr><<A href="mailto:kgharris@sonic.net"
target=_blank>kgharris@sonic.net</A>></SPAN> wrote:<BR>
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<DIV bgcolor="#ffffff">
<DIV><FONT size=2 face=Arial>Dean,</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Thank you for bringing this up. I have
never really thought about there being a difference between pyrolysis
and gasification. The definition of gasification in Wikipedia, "<FONT
size=3 face="Times New Roman">This is achieved by reacting the material at
high temperatures (>700 °C), without combustion, with a controlled amount
of </FONT><FONT size=3 face="Times New Roman">oxygen</FONT><FONT size=3
face="Times New Roman"> and/or </FONT><FONT size=3
face="Times New Roman">steam",</FONT> is different from the
definition of pyrolysis which is without additional oxygen. Your
statement seems correct according to this. </FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>As I read further in Wikipedia, there is a
section on chemical reactions. Here there are 5 different processes
which the fuel undergoes, pyrolysis being one of those. This would
lead me to believe that pyrolysis is part of the more general process
of gasification. Rather than it being one or the
other, a TLUD would include both. The small amount of added
air supports the combustion of a small amount of the gas to produce
heat, but that air is soon used up and most of the fuel pyrolyzes without
added air. The combination, including pyrolysis, would
be gasification.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>I will look further to see if Christa
Roth adresses this question in her Micro-gasification
manual. </FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Kirk</FONT></DIV>
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<DIV style="FONT: 10pt arial; font-stretch: normal">----- Original Message
----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: rgb(228,228,228); font-stretch: normal"><B>From:</B>
<A title=deankstill@gmail.com href="mailto:deankstill@gmail.com"
target=_blank>Dean Still</A> </DIV>
<DIV style="FONT: 10pt arial; font-stretch: normal"><B>To:</B> <A
title=stoves@lists.bioenergylists.org
href="mailto:stoves@lists.bioenergylists.org" target=_blank>Discussion of
biomass cooking stoves</A> </DIV>
<DIV style="FONT: 10pt arial; font-stretch: normal"><B>Sent:</B> Saturday,
May 16, 2015 3:50 PM</DIV>
<DIV style="FONT: 10pt arial; font-stretch: normal"><B>Subject:</B>
[Stoves] Pyrolysis: No Air?</DIV>
<DIV><BR></DIV>
<DIV dir=ltr>
<OL
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<LI
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<DIV style="PADDING-BOTTOM: 20px; OVERFLOW: hidden">Hi
All,</DIV></LI></OL>
<DIV><SPAN style="LINE-HEIGHT: 16px">When I look up the word pyrolysis I
find the following:</SPAN></DIV>
<OL
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<LI
style="BORDER-BOTTOM: 0px; BORDER-LEFT: 0px; PADDING-BOTTOM: 0px; LINE-HEIGHT: 1.24; LIST-STYLE-TYPE: none; MARGIN: 0px; PADDING-LEFT: 20px; PADDING-RIGHT: 20px; CLEAR: none; BORDER-TOP: 0px; BORDER-RIGHT: 0px; PADDING-TOP: 20px">
<DIV style="PADDING-BOTTOM: 20px; OVERFLOW: hidden"><B
style="LINE-HEIGHT: 1.24; FONT-SIZE: 16px">Pyrolysis</B><SPAN
style="LINE-HEIGHT: 1.24; FONT-SIZE: 16px"> </SPAN><SPAN
style="LINE-HEIGHT: 1.24; FONT-SIZE: 16px">is a thermochemical
decomposition of organic material at elevated temperatures in the
absence of oxygen (or any halogen). It involves the simultaneous change
of chemical composition and physical phase, and is irreversible. The
word is coined from the Greek-derived elements pyro "fire" and lysis
"separating".</SPAN></DIV>
<LI
style="BORDER-BOTTOM: 0px; BORDER-LEFT: 0px; PADDING-BOTTOM: 0px; LINE-HEIGHT: 1.24; LIST-STYLE-TYPE: none; MARGIN: 0px; PADDING-LEFT: 20px; PADDING-RIGHT: 20px; CLEAR: none; BORDER-TOP: 0px; BORDER-RIGHT: 0px; PADDING-TOP: 20px">
<DIV style="PADDING-BOTTOM: 20px; OVERFLOW: hidden"><SPAN
style="LINE-HEIGHT: 1.24; FONT-SIZE: 16px">However, I think that folks
use it to describe what happens in a TLUD, etc? Isn't that gasification
not pyrolysis because of the presence of some air?</SPAN></DIV></LI></OL>
<DIV><SPAN style="LINE-HEIGHT: 19px; FONT-SIZE: 16px">Best,</SPAN></DIV>
<DIV><SPAN style="LINE-HEIGHT: 19px; FONT-SIZE: 16px"><BR></SPAN></DIV>
<DIV><SPAN
style="LINE-HEIGHT: 19px; FONT-SIZE: 16px">Dean</SPAN></DIV></DIV>
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<P align=left color="#000000">No virus found in this message.<BR>Checked
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<P align=left color="#000000" avgcert??>No virus found in this
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