[Stoves] please remove NDABAWPT at MSN.COM from your mailing list
Robert Kowalczyk
ndabawpt at msn.com
Tue Apr 10 09:58:41 CDT 2007
Robert J. Kowalczyk
>From: stoves-request at listserv.repp.org
>Reply-To: stoves at listserv.repp.org
>To: stoves at listserv.repp.org
>Subject: Stoves Digest, Vol 10, Issue 14
>Date: Tue, 10 Apr 2007 07:39:48 -0500
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>Today's Topics:
>
> 1. Re: Re Alexis Belonio article (Thomas Reed)
> 2. Re: Magh Smoke Burner Stove (Paul S. Anderson)
> 3. Re: Magh Smoke Burner Stove (Tom Miles)
> 4. Re: Re Alexis Belonio article (Peter Verhaart)
> 5. Re: Charcoal & Stoves (AJH)
> 6. Re: Magh Smoke Burner Stove (AJH)
> 7. Re: [Gasification] gas composition (AJH)
> 8. Re: Magh Smoke Burner Stove (AJH)
> 9. Char from TLUDs and retorts (Paul S. Anderson)
>
>
>----------------------------------------------------------------------
>
>Message: 1
>Date: Mon, 09 Apr 2007 15:20:41 -0600
>From: Thomas Reed <tombreed at comcast.net>
>Subject: Re: [Stoves] Re Alexis Belonio article
>To: Crispin Pemberton-Pigott <crispin at newdawn.sz>, Discussion of
> biomass cooking stoves <stoves at listserv.repp.org>
>Message-ID: <461AAE29.10401 at comcast.net>
>Content-Type: text/plain; charset=ISO-8859-15; format=flowed
>
>Dear Crispin:
>
>There is no such reactant as "O", it is always written "O2" (O is a free
>radical and begins to be important above 3,000C). Same for hydrogen,
>always H2 below 3000 C.
>
>The Water gas shift reaction is CO + H2O <==> CO2 + H2. DH(reaction) ~
>0, so the reaction is energy neutral and driven by entropy considerations.
>
>The equilibrium values depend on the temperature, so I use the double
>arrow. At temperatures above 700 C, the reverse reaction makes CO. At
>temperatures below 700 C H2 begins to be favored.
>
>All of this is explained in gory detail in our "Encyclopedia of Biomass
>Thermal Conversion" (at www.woodgas.com). You may not want to know the
>details, but the above outlines the facts of life in the hydrogen lane.
>
>Yours truly,
>
>TOM REED CHIEF CHEMIST, BEF
>------------------------------------------------------------------------
>
>Crispin Pemberton-Pigott wrote:
> > Dear Penn
> >
> > Do you know the temperature at which might take place?
> >
> >
> >> 2 CO + H2O + O --> 2 CO2 + 2 H
> >>
> >
> > Thanks
> > Crispin
> >
> > _______________________________________________
> > Stoves mailing list
> > Stoves at listserv.repp.org
> > http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org
> > http://www.bioenergylists.org
> >
> >
> >
>
>
>------------------------------
>
>Message: 2
>Date: Mon, 09 Apr 2007 17:10:42 -0500
>From: "Paul S. Anderson" <psanders at ilstu.edu>
>Subject: Re: [Stoves] Magh Smoke Burner Stove
>To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>,
> Thomas Reed <tombreed at comcast.net>
>Cc: Shivayam Ellis <shivayam.ellis at comcast.net>, James Becker
> <JamesBecker at peakpeak.com>
>Message-ID: <20070409171042.5oibvuvccgwwooco at webmail2.ilstu.edu>
>Content-Type: text/plain; charset=ISO-8859-1; format="flowed"
>
>
>Quoting Thomas Reed <tombreed at comcast.net>:
> >
> > So, if you are willing to use only the volatiles and use the charcoal
> > for terra pretta (or mix it back in with the next batch of wood), you
> > can avoid stainless.
>
>The above refers to TLUDs. And IF the use is ONLY for the pyrolysis gases,
>there is no reason to put the charcoal back into the next batch of wood
>because
>there are no sources of pyrolysis gases in that char.
>
>Paul
>
>----------------------------------------------------------------
>This message was sent using Illinois State University Webmail.
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>
>
>
>
>------------------------------
>
>Message: 3
>Date: Mon, 9 Apr 2007 15:51:11 -0700
>From: "Tom Miles" <tmiles at trmiles.com>
>Subject: Re: [Stoves] Magh Smoke Burner Stove
>To: "'Discussion of biomass cooking stoves'"
> <stoves at listserv.repp.org>
>Message-ID: <009601c77af9$921eb5c0$b65c2140$@com>
>Content-Type: text/plain; charset="us-ascii"
>
>Part of the fixed carbon in the fuel is undoubtedly consumed during
>gasification. What is the carbon conversion efficiency of the TLUD? Has
>anyone compared the actual amount of char produced in a TLUD with the
>amount
>of char that would be produced if only the volatiles were burned?
>
>Tom Miles
>
>
>-----Original Message-----
>From: stoves-bounces at listserv.repp.org
>[mailto:stoves-bounces at listserv.repp.org] On Behalf Of Paul S. Anderson
>Sent: Monday, April 09, 2007 3:11 PM
>To: Discussion of biomass cooking stoves; Thomas Reed
>Cc: Shivayam Ellis; James Becker
>Subject: Re: [Stoves] Magh Smoke Burner Stove
>
>
>Quoting Thomas Reed <tombreed at comcast.net>:
> >
> > So, if you are willing to use only the volatiles and use the charcoal
> > for terra pretta (or mix it back in with the next batch of wood), you
> > can avoid stainless.
>
>The above refers to TLUDs. And IF the use is ONLY for the pyrolysis gases,
>there is no reason to put the charcoal back into the next batch of wood
>because
>there are no sources of pyrolysis gases in that char.
>
>Paul
>
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>------------------------------
>
>Message: 4
>Date: Tue, 10 Apr 2007 11:14:32 +1000
>From: Peter Verhaart <pverhaart at iprimus.com.au>
>Subject: Re: [Stoves] Re Alexis Belonio article
>To: Crispin Pemberton-Pigott <crispin at newdawn.sz>, Discussion of
> biomass cooking stoves <stoves at listserv.repp.org>
>Message-ID: <461AE4F8.3080000 at iprimus.com.au>
>Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>Dear Crispin,
>
>I am sure steam does not decompose into Hydrogen and Oxygen. One thing
>steam (or any other inert gas) can do is impart momentum and so force
>the mixture to flow to where you want it to go. In other cases steam can
>increase the volume of the mixture and so present a larger surface area
>to enable smokeless burning. This only works with rich volatiles of course.
>As to Hydrogen IC (internal combustion) engines. Boloney!
>Theoretically to produce Hydrogen by electrolysis (the most efficient
>way from an energy viewpoint) of water requires the same amount of
>energy that is released upon burning the Hydrogen. In practice it
>requires more due to resistance. Burning Hydrogen or any other fuel in
>an IC engine will produce an efficiency of 40 % in the largest engines,
>much more likely 25 % in reasonably sized engines.
>The car would run much further if the batteries powered electric motors
>directly.
>Bombarding the electrolysis cell with radio waves, if it worked (which I
>don't believe) would in the best case scenario lessen the electrolysis
>energy by the energy input of the radio waves.
>
>
>Crispin Pemberton-Pigott wrote:
> > Dear Friends of Science
> >
> >
> >>> Meyers was proven to be one of the biggest scam artists on the planet.
> >>> Please do not be taken in by any of his work.
> >>>
> >
> >
> >> Now, now, Meyers has many contenders for this "honor", with people
> >> like Daniel Dingel who claimed to be a NASA engineer but didn't know
> >> what an explosion was.
>
>
>
>------------------------------
>
>Message: 5
>Date: Tue, 10 Apr 2007 11:52:04 +0100
>From: AJH <list at sylva.icuklive.co.uk>
>Subject: Re: [Stoves] Charcoal & Stoves
>To: Crispin Pemberton-Pigott <crispin at newdawn.sz>, Discussion of
> biomass cooking stoves <stoves at listserv.repp.org>
>Message-ID: <etmm13tjkae80ie9e4u1nl154ndd253u1e at 4ax.com>
>Content-Type: text/plain; charset=us-ascii
>
>On Sun, 8 Apr 2007 18:47:55 -0400, Crispin Pemberton-Pigott wrote:
>
> >Dear Michael
> >
> >In experiments done with Tsotso stoves in 1999 I encountered the same
> >problem of smouldering coconut husks. They are 'burning' but not with a
> >flame. The attached picture shows the Tsotso boiling a cast iron pot of
> >water with limited smoke.
>
>I take it this was a reply to an offlist post as I cannot see the
>original?
> >
> >The solution I found at the time that made an impact (i.e. created a
>flame)
> >was to get the primary air preheated to the point where the addition of
>the
> >smouldering heat was sufficient to maintain a flame.
>
>This seems a sensible approach where either the cv of the gas you are
>trying to burn is low or below it's spontaneous ignition temperature.
>There must be many reasons why a combustible gas won't support a
>flame, low enthalpy and wrong gas velocity would be two.
>
>
> > I was wondering it
> >your TLUD stove might be able to burn the smoke. It might be quite damp
> >smoke which is a huge drawback.
>
>This would depend on the secondary burner, generally the hot tarry gas
>from a tlud is a very high cv, principally because the thing only
>works with relatively dry fuels.
> >
> >I also found that the burn rate was also important because it raises the
> >fuel temperature more rapidly.
>
>This would be because the increased heat flux outpaced local heat
>losses, the same happens when blowing on a smouldering fire, the
>overall increase in excess air is offset by the local high velocity
>air gasifying char, thus increasing temperature above the spontaneous
>ignition temperature of the offgas and initiating a flame.
>
> > You can get the burn rate up by increasing
> >the draft with a chimney, increasing the internal stove height (internal
> >chimney), blowing on it (as with a fan), or mixing other things into the
> >fuel (like oily nuts).
>
>Oily nuts would both increase the cv and produce an offgas with a low
>spontaneous ignition temperature compared with pyrolysis offgas, the
>same is true of old resinous wood.
>
> >and most of the fuel goes off as dense smoke.
>
>Which of course is wasted energy, so this is a negative feedback.
>
> >
> >I am optimistic that your TLUD will be able to burn at least parts of the
> >husk well.
>
>I'd like to see the attempt made but in general the poor heat feedback
>of the tlud men as I'm not optimistic, a simple updraught, well
>insulated, serially batch fed stove with some heat re circulation
>looks the way to go.
>
>If it is a wet fuel then the char route may offer a way of refining it
>to an acceptable fuel and the briquetting will increase the bulk
>density.
>
>AJH
>
>
>
>
>
>------------------------------
>
>Message: 6
>Date: Tue, 10 Apr 2007 11:52:05 +0100
>From: AJH <list at sylva.icuklive.co.uk>
>Subject: Re: [Stoves] Magh Smoke Burner Stove
>To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>
>Message-ID: <l7om135vshvetbivbajc8qgmvgo409uvia at 4ax.com>
>Content-Type: text/plain; charset=us-ascii
>
>On Mon, 9 Apr 2007 15:51:11 -0700, Tom Miles wrote:
>
> >Part of the fixed carbon in the fuel is undoubtedly consumed during
> >gasification.
>
>In fact as I have said many times before everything points to the fact
>that the bulk of the heat used for the pyrolysis process is from a low
>temperature oxidation of the carbon content, you'll see reports that
>the char yield falls with the moisture content of the fuel, in fact it
>is difficult to sustain a tlud secondary burn when the mc exceeds 30%.
>
>If you look at the post Tom Reed crossposted from John Bertl you will
>appreciate why this may be so, also it indicates why the size of
>particle a tlud may be limited, because the rate, and hence time
>involved, is determined by the amount of heat that can be conducted
>into the wood particle, and this is to do with both surface area
>(proportionately this decreases with square of dimension) and path
>length (increases linearly with dimension).
>
>
> > What is the carbon conversion efficiency of the TLUD?
>
>I've not managed better than 25% of the dry weight, whereas with a low
>temperature retort I've achieved 45% albeit with a <80% fixed carbon,
>at a guess.
>
> > Has
> >anyone compared the actual amount of char produced in a TLUD with the
>amount
> >of char that would be produced if only the volatiles were burned?
>
>That's a "how long is a piece of string " question because it depends
>on the initial composition of the biomass and the temperature of
>pyrolysis (and dwell time the wood is subjected to the temperature)
>With wood slow pyrolysis at >450C will yield a char with ~82% fixed
>carbon.
>
>AJH
>
>
>
>
>------------------------------
>
>Message: 7
>Date: Tue, 10 Apr 2007 11:52:06 +0100
>From: AJH <list at sylva.icuklive.co.uk>
>Subject: Re: [Stoves] [Gasification] gas composition
>To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>
>Cc: John Bertl <jbertl at hotmail.com>
>Message-ID: <pdpm13940idbcbvrgiuau0l9dpd07g5np1 at 4ax.com>
>Content-Type: text/plain; charset=us-ascii
>
>On Mon, 09 Apr 2007 08:33:19 -0600, Thomas Reed wrote:
>
> >Dear John Bertl and all:
> >
> >Your list doesn't help much since it doesn't prioritize the components.
>
>That's an ungracious reply Tom, John's post is a concise appreciation
>of pyrolysis under different conditions, I'm sure most stovers will
>find it informative even though it was initilaly posted in
>[gasification] and I don't believ John reads [stoves].
>
>It's up to other to add to the bones of it, with details as you
>posted, to give the full story.
>
> >The pyrolysis equations on the other hand do, for instance
> >
> >CH1.4O0.6 +0.2 H2O (15%, typical) ==> 0.4CO + (0.2CO2 + 0.9H2) DH
> >= 364 kJ/gmole
> >
> >The hydrogen makes it easy to burn the gas in either a turbulent or
> >diffusion flame. The rest of the cats and dogs are tars and don't add
> >much energy to the fire but do contribute to the luminosity. (The CO,
> >CO2 and H2 will equilibrate to some extent and greatly complicate the
> >calculations).
> >
> >Yours truly,
> >
> >TOM REED BEF
> >
> >
> >John Bertl wrote:
> >> On Friday 06 April 2007 11:59 am, Louis Peltier wrote:
> >>
> >>> could some one tell me what the gas composition is
> >>> when wood is heated in a CLOSED container to make charcoal.
> >>> (no air is allowed in the closed container)
> >>
> >> The gas composition you are asking for depends on the speed
> >> of temperature rise (speed of pryralysis), the temperature
> >> experience by the wood, the time duration of the gas at
> >> elevated temperatures and if the gas can escape your
> >> closed container to be cooled.
> >>
> >> The possible gases produced are:
> >>
> >> H2O =
> >> CO2 = S
> >> RCOOH = L
> >> CO = O =
> >> RCHO = W =
> >> CH2CO = =
> >> ROH = F
> >> CH4 = A
> >> C2H6 = S
> >> H2 = T
> >> C2H4 =
> >> C2H2 =
> >> free radicals:
> >> CH, CH2, CH3, CHO 2 to 10
> >> C2
> >>
> >> Slow pyrolysis yields charcoal and oxygenated gases
> >> and vapors of low flammability and releases energy.
> >>
> >> Fast pyrolysis yields little of no carbon, forms
> >> hydrogenated gases and vapors and consumes
> >> energy
> >>
> >> Pyrolysis of wood follows the kinetics of a first
> >> order reaction. It is diffusion controlled rather
> >> than rate controlled, the rate being determined
> >> by the rate of energy transfer within the solid
> >> rather than by the rate of pyrolysis.
> >>
> >> Breakdown of wood components, hemicellulose,
> >> cellulose and lignin, is not simultaneous. The
> >> hemicellulose, particularly its pentosans, are said
> >> to decompose first largely between 200 and
> >> 260C followed by the cellulose at 240 to 350 C
> >> and finally by the lignin at 280 to 500 C.
> >>
> >> Hemicellulose evolves more gases, less tar, and
> >> about as much aqueous distillate as are formed
> >> from cellulose, but differs from cellulose in that
> >> hemicellulose yields no levolucosan. Much of the
> >> acetic acid formed is attributed to the hemicellulose.
> >> Scission of a carbon to oxygen bond in a
> >> pentose leads to further splitting to acetic acid,
> >> formaldhyde, carbon monoxide and hydrogen.
> >>
> >> Cellulose evolves water in the first stage of
> >> thermal decomposition before any other significant
> >> changes are observable.
> >>
> >> The pyrolytic products first formed from hemicellulose,
> >> cellulose and lignin promptly undergo
> >> further reactions, not all of which are pyrolytic.
> >> Polymerizations and condensations reactions to
> >> form more comples molecules such as high boiling tars,
> >> waxes and resinous substances with perhaps
> >> phenolformaldehyde type linkages are also involved.
>
>Informative post John
>
>AJH
>
>
>
>------------------------------
>
>Message: 8
>Date: Tue, 10 Apr 2007 11:52:06 +0100
>From: AJH <list at sylva.icuklive.co.uk>
>Subject: Re: [Stoves] Magh Smoke Burner Stove
>To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>
>Message-ID: <82qm139gaqgtst491uensg25752jnmguqv at 4ax.com>
>Content-Type: text/plain; charset=us-ascii
>
>On Mon, 09 Apr 2007 17:10:42 -0500, Paul S. Anderson wrote:
>
> >
> >Quoting Thomas Reed <tombreed at comcast.net>:
> >>
> >> So, if you are willing to use only the volatiles and use the charcoal
> >> for terra pretta (or mix it back in with the next batch of wood), you
> >> can avoid stainless.
>
>Taken to the ultimate conclusion the stove would simply choke up with
>ash, if you sift out the ash then you can recycle the char a number of
>times. When john Davies posted about getting the high sulphur offgas
>from bitumous coal to burn (in ~2000 he reported people left the stove
>outside to drive off unburnt offgas and only used it once the fossil
>coal was reduced to burning coke)I found one way to get around the
>problem was a tlud burn but recycling sifted coke back alongside or on
>top of the fresh coal. Ronal and I had to eat a cold fish supper
>because we stayed outside playing with it too long.
>
> >The above refers to TLUDs. And IF the use is ONLY for the pyrolysis
>gases,
> >there is no reason to put the charcoal back into the next batch of wood
> >because
> >there are no sources of pyrolysis gases in that char.
>
>There will still be some Paul but the char will still burn tlud, have
>a try, from memory the downward rate of spread of the fire is much
>faster as the fire front only has to heat dry char to its ignition
>temperature.
>
>A simple experiment would be to fill a 1m by 150mm diameter flue pipe
>and mark the outside with a fixed length crayon mark, the speed of
>progress of the fire downward could be timed.
>
>One of the things I never resolved about a long stack tlud fire was
>how the air supply varied as the column of hot gases above the fire
>lengthened and the column of fuel (and its resistance to air and
>offgas) shrank. I think there is a need for an experiment with a
>constant mass air supply.
>
>The other thing I didn't do yet is to run comparable experiments with
>inclined tubes to see how far off vertical the tube would still
>function in tlud mode. This of course is more of interest in the
>production of char rather than a functional cookstove. It's a shame
>your visit was brief and only in London, you may have enthused me to
>have a go!
>
>AJH
>
>
>
>
>------------------------------
>
>Message: 9
>Date: Tue, 10 Apr 2007 07:39:44 -0500
>From: "Paul S. Anderson" <psanders at ilstu.edu>
>Subject: [Stoves] Char from TLUDs and retorts
>To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>,
> AJH <list at sylva.icuklive.co.uk>
>Message-ID: <20070410073944.wtc3umo1kws84cc0 at webmail2.ilstu.edu>
>Content-Type: text/plain; charset=ISO-8859-1; format="flowed"
>
>Andrew,
>
>It was nice to have met you in London.
>
>My question is below:
>
>Quoting AJH <list at sylva.icuklive.co.uk>:
>
>About the carbon conversion efficiency of the TLUD:
> >
> > I've not managed better than 25% of the dry weight, whereas with a low
> > temperature retort I've achieved 45% albeit with a <80% fixed carbon,
> > at a guess.
>
>In the TLUD the heat for pyrolysis came from the fuel. But in the retort,
>was
>the heat from an outside source? If so, how much heat, and how does that
>amount of outside heat relate to the heat used by the TLUD?
>
>Also, if the TLUD's 25% char was nearly 100% fixed carbon, and the
>retort's 45%
>char was less than 80% fixed carbon, a full 20% of 45% (which is 9%) should
>be
>reduced from the retort's output, meaning at best only 36% fixed carbon
>output
>from the retort (with outside heat source) should be compared with the
>25% from
>the TLUD that had to supply its own heat.
>
>Are we seeing that TLUD production of char could be about as productive as
>retort production of char?
>
>Andrew, I am pushing the limits of my knowledge here. Please be gentle as
>you
>teach me!!!! :-))
>
>Paul
>
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>I have appreciated so much from you folks. Thank you. Now at a time in my
>life when disease is having a noticable effect on my abilities I would like
>to spend more time with the quest for a cure for my terminal cancer. PLEASE
>STOP THE FOREWARDING OF YOU INFORMATION.
sINCERELY ROBERT j. kOWALCZYK NDABAWPT at MSN.COM tHYANK yOU. bY THE WAY THIS
IS THE THIRD TIME i HAVE ASKED.
>
>
>
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