May 2003 Gasification Archive

For more information to help people develop better stoves for cooking with biomass fuels in developing regions, please see our web site: http://www.bioenergylists.org

From tmiles at TRMILES.COM Thu May 1 15:05:26 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:21 2004
Subject: Great grates? - Tom M
Message-ID: <THU.1.MAY.2003.150526.0400.TMILES@TRMILES.COM>

Crispin,

I think it was a good idea. After a while you probably get a bed of coals
that fills the floor of the Maendeleo and the effect of the shelf probably
disappears. I wonder if anyone has put holes for combustion air below the
shelf.

It seems like there might be some small variations like that which would
improve the efficiency while preserving portability, simplicity and other
attributes of the Maendaleo design.

Tom

On Wed, 30 Apr 2003 11:09:03 +0200, Crispin <crispin@NEWDAWN.SZ> wrote:

>Dear Tom
>
>The point of the Maendeleo stove floor shape was raised at at the
>Vereeniging conference. Apparently they sometimes put a narrow clay shelf
>across the _front_ to hold the fuel up off the floor of coals slightly.
>This is not an approximation of the layout of a Rocket but it does keep
the
>wood off the cold floor when starting off. It seems like a good idea.
>
>Regards
>Crispin
>

From hseaver at CYBERSHAMANIX.COM Fri May 2 09:49:42 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:21 2004
Subject: New Can opener &safety tip
In-Reply-To: <000501c3107f$9c7d1540$36d0fea9@desmond>
Message-ID: <FRI.2.MAY.2003.084942.0500.HSEAVER@CYBERSHAMANIX.COM>

I remember seeing canning outfits like that back about 25 years ago, haven't
noticed them lately but then haven't been looking either. I think the glass jar
canning method probably put them out of business.
Also that "new" can-opener Tom found isn't all that new, it probably dates
back to the time of the can re-sealers, but certainly I know we had bought a new
opener of that type probably about 20 years ago. They were being touted as
having some advantage or other, possibly related to recycling, but I can't
remember now.
Along these lines, someone on another list was trying to tell me that no one
in the British isles every does food canning and that such equipment (the glass
jar type) wasn't available there. I felt that surely he was just clueless, but
who knows. Is food preservation by canning used much in Europe or the rest of
the world?

On Mon, Apr 28, 2003 at 07:56:13AM +0200, Crispin wrote:
> Dear Stoves and can recyclers
>
> Some of you might be old enough to rememebr that before and after WWII
> people kept the cans, filled them with food they wanted to store and put on
> new tops. The cans slowly get shorter and shorter until they look like tuna
> cans after a number of uses.
>
> I wonder if the lids and hand-operated re-sealer is still available.
>
> Regards
> Crispin

--
Harmon Seaver
CyberShamanix
http://www.cybershamanix.com

From andrew.heggie at DTN.NTL.COM Fri May 2 15:42:22 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:21 2004
Subject: New Can opener &safety tip
In-Reply-To: <20030502134942.GA7994@cybershamanix.com>
Message-ID: <FRI.2.MAY.2003.204222.0100.>

On Fri, 2 May 2003 08:49:42 -0500, Harmon Seaver wrote:

> I remember seeing canning outfits like that back about 25 years ago, haven't
>noticed them lately but then haven't been looking either. I think the glass jar
>canning method probably put them out of business.

I wonder which came first? I understand Bonaparte's army preserved
peas in champagne bottles sealed with wax.

What is the derivation of the word "canning"?

> Also that "new" can-opener Tom found isn't all that new, it probably dates
>back to the time of the can re-sealers, but certainly I know we had bought a new
>opener of that type probably about 20 years ago. They were being touted as
>having some advantage or other, possibly related to recycling, but I can't
>remember now.

I did not realise these resealers were available for domestic use, can
you point me to a picture of one?

The main advantage to me is that the lid does not drop into the
contents.

> Along these lines, someone on another list was trying to tell me that no one
>in the British isles every does food canning and that such equipment (the glass
>jar type) wasn't available there. I felt that surely he was just clueless, but
>who knows. Is food preservation by canning used much in Europe or the rest of
>the world?

I think there is a difference in our common language, the jars we
use(d) are called kilner jars. They are rugged, often ribbed, screw
topped glass jars, The top is in 3 pieces, a flat glass disc, a rubber
gasket to seal the disc to the jar and a metal screw cap to initially
create the seal. I always knew it as "preserving" and until quite
recently did not realise the term "canning" could be applied other
than to the use of metal cans.

AJH

From hseaver at CYBERSHAMANIX.COM Fri May 2 20:15:44 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:21 2004
Subject: New Can opener &safety tip
In-Reply-To: <b5h5bvov4eoddm9732t4lkfh7mbtah077m@4ax.com>
Message-ID: <FRI.2.MAY.2003.191544.0500.HSEAVER@CYBERSHAMANIX.COM>

On Fri, May 02, 2003 at 08:42:22PM +0100, Andrew Heggie wrote:
> On Fri, 2 May 2003 08:49:42 -0500, Harmon Seaver wrote:
>
> > I remember seeing canning outfits like that back about 25 years ago, haven't
> >noticed them lately but then haven't been looking either. I think the glass jar
> >canning method probably put them out of business.
>
> I wonder which came first? I understand Bonaparte's army preserved
> peas in champagne bottles sealed with wax.
>
> What is the derivation of the word "canning"?

I'm sure it was the resealing of tins originally.

>
> > Also that "new" can-opener Tom found isn't all that new, it probably dates
> >back to the time of the can re-sealers, but certainly I know we had bought a new
> >opener of that type probably about 20 years ago. They were being touted as
> >having some advantage or other, possibly related to recycling, but I can't
> >remember now.
>
> I did not realise these resealers were available for domestic use, can
> you point me to a picture of one?

Yes they definitely were for home use, I remember them well, but no, I don't
know of a picture of one. I did a google search earlier today, but came up with
too many hits for bottle resealers.

>
> The main advantage to me is that the lid does not drop into the
> contents.
>
> > Along these lines, someone on another list was trying to tell me that no one
> >in the British isles every does food canning and that such equipment (the glass
> >jar type) wasn't available there. I felt that surely he was just clueless, but
> >who knows. Is food preservation by canning used much in Europe or the rest of
> >the world?
>
> I think there is a difference in our common language, the jars we
> use(d) are called kilner jars. They are rugged, often ribbed, screw
> topped glass jars, The top is in 3 pieces, a flat glass disc, a rubber
> gasket to seal the disc to the jar and a metal screw cap to initially
> create the seal. I always knew it as "preserving" and until quite
> recently did not realise the term "canning" could be applied other
> than to the use of metal cans.
>
> AJH

Well, that's what I thought it was at first, but this guy kept insisting that
people there only used freezing and pickling. I suspect he was perhaps quite
young, even asked him if he'd been gardening long, but never got a straight
answer.

So you don't have the more modern jars with the screw on, two piece metal
lid? The thin metal center part forms the seal, then is thrown away after one
use. We've got a lot of older jars like you describe, but don't use them much,
they're worth more as antiques actually, to risk breaking in the pressure
cooker. We've also got quite a few of the older style with the solid glass top,
rubber seal ring, and a heavy wire bail that snaps over the top to hold it in
place. Only use those for some foods which are also decorative, these days.

--
Harmon Seaver
CyberShamanix
http://www.cybershamanix.com

From hotspringfreak at HOTMAIL.COM Sat May 3 03:58:44 2003
From: hotspringfreak at HOTMAIL.COM (Chris Smith)
Date: Tue Aug 10 18:30:21 2004
Subject: New Can opener & safety tip
Message-ID: <SAT.3.MAY.2003.005844.0700.HOTSPRINGFREAK@HOTMAIL.COM>

Crispin <crispin@newdawn.sz> asks:

> I wonder if the lids and hand-operated re-sealer is still available.

"Tin" can sealers - here's one source.

http://www.wellscan.ca/sealers.htm

- Chris Smith

From andrew.heggie at DTN.NTL.COM Sat May 3 06:22:25 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:21 2004
Subject: New Can opener &safety tip
In-Reply-To: <20030503001544.GA8605@cybershamanix.com>
Message-ID: <SAT.3.MAY.2003.112225.0100.>

On Fri, 2 May 2003 19:15:44 -0500, Harmon Seaver wrote:

>> I think there is a difference in our common language, the jars we
>> use(d) are called kilner jars. They are rugged, often ribbed, screw
>> topped glass jars, The top is in 3 pieces, a flat glass disc, a rubber
>> gasket to seal the disc to the jar and a metal screw cap to initially
>> create the seal. I always knew it as "preserving" and until quite
>> recently did not realise the term "canning" could be applied other
>> than to the use of metal cans.
>>
>> AJH
>
>
> Well, that's what I thought it was at first, but this guy kept insisting that
>people there only used freezing and pickling. I suspect he was perhaps quite
>young, even asked him if he'd been gardening long, but never got a straight
>answer.

I don't recollect seeing preserving/kilner jars used since the 50s, I
imagine freezing became prevalent by the 60s.
>
> So you don't have the more modern jars with the screw on, two piece metal
>lid? The thin metal center part forms the seal, then is thrown away after one
>use.

Now you mention it I believe I have seen this type where a metal disc
replaces the glass one.

> We've got a lot of older jars like you describe, but don't use them much,
>they're worth more as antiques actually, to risk breaking in the pressure
>cooker. We've also got quite a few of the older style with the solid glass top,
>rubber seal ring, and a heavy wire bail that snaps over the top to hold it in
>place. Only use those for some foods which are also decorative, these days.

I do still have one with the wire over centre latch, this system was
also used on pop and beer bottles where the stopper was ceramic with a
rubber sealing ring, in fact I believe it is still used on some beers.

AJH

From andrew.heggie at DTN.NTL.COM Sat May 3 06:22:29 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:21 2004
Subject: New Can opener & safety tip
In-Reply-To: <Law10-OE587r4nZrKoU00008ff0@hotmail.com>
Message-ID: <SAT.3.MAY.2003.112229.0100.>

On Sat, 3 May 2003 00:58:44 -0700, Chris Smith wrote:

>Crispin <crispin@newdawn.sz> asks:
>
>> I wonder if the lids and hand-operated re-sealer is still available.
>
>"Tin" can sealers - here's one source.
>
>http://www.wellscan.ca/sealers.htm

I'd be fascinated to see one working, but USD163 is a bit much for
that.

Do you buy new tinplate lids to use? Are they just flat discs with the
machine doing all the rolling? Is any sealant used?

AJH

From kchisholm at CA.INTER.NET Sat May 3 07:32:45 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:21 2004
Subject: New Can opener & safety tip
Message-ID: <SAT.3.MAY.2003.083245.0300.KCHISHOLM@CA.INTER.NET>

Dear Andrew

> >"Tin" can sealers - here's one source.
> >
> >http://www.wellscan.ca/sealers.htm
>
> I'd be fascinated to see one working, but USD163 is a bit much for
> that.

I don't know if you have checked recently, but that is now less than 100
British Pounds. Check again in a months time. :-)
>
> Do you buy new tinplate lids to use? Are they just flat discs with the
> machine doing all the rolling? Is any sealant used?

The name here is "Mason Jar". They have a sheetmetal top, with a slight
indentation where the top sits on the mouth of the jar. A red rubbery gasket
material, like partially cured rubber, is put into this depression. Its
nature is such that under pressure, it flows.

When the preserves start to cool, they draw a vacuum in the ullage. This
puls the cap down tightly to the rim of the jar. Invariablw a perfect seal
is attained. The top of the cover is slightly crowned; when adequate vacuum
is attained, the cover "POPS", indicating that teh jar is fully sealed and
that no air has leaked in.

Clever, eh?

Kevin
>
> AJH

From hseaver at CYBERSHAMANIX.COM Sat May 3 09:34:17 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:22 2004
Subject: New Can opener & safety tip
In-Reply-To: <002601c31167$b9acd040$a59a0a40@kevin>
Message-ID: <SAT.3.MAY.2003.083417.0500.HSEAVER@CYBERSHAMANIX.COM>

On Sat, May 03, 2003 at 08:32:45AM -0300, Kevin Chisholm wrote:
> > Do you buy new tinplate lids to use? Are they just flat discs with the
> > machine doing all the rolling? Is any sealant used?
>
> The name here is "Mason Jar". They have a sheetmetal top, with a slight
> indentation where the top sits on the mouth of the jar. A red rubbery gasket
> material, like partially cured rubber, is put into this depression. Its
> nature is such that under pressure, it flows.
>
> When the preserves start to cool, they draw a vacuum in the ullage. This
> puls the cap down tightly to the rim of the jar. Invariablw a perfect seal
> is attained. The top of the cover is slightly crowned; when adequate vacuum
> is attained, the cover "POPS", indicating that teh jar is fully sealed and
> that no air has leaked in.
>

Are you talking about the cans or the jars? "Mason" is a brand of glass jars,
like "Ball", "Kerr", and a few others. The can sealer is a totally different
thing. Our metal capped jars with the rubber ring, and the newer ones with the
two part metal top both vacuum seal essentially as you describe, but the older,
glass topped rubber ringed jars don't, I think, but rely on the mechanical
pressure of the wire clampsB.
BTW, my wife showed me the difference last night between French, German, and
Italian canning jars, seems she has more of a collection than I thought, and
each of those seals up a bit differently than our older glass top Mason, Ball,
and Kerr jars.
At any rate, I'm glad someone found a source for the can resealers, I'm
putting that on my wish list. Can't have too large a food store in these
perilous times, IMHO. In the US, most cities have, at most, only 3 days of food
if delivery stopped.

--
Harmon Seaver
CyberShamanix
http://www.cybershamanix.com

From hseaver at CYBERSHAMANIX.COM Sat May 3 11:44:21 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:22 2004
Subject: tincanium
Message-ID: <SAT.3.MAY.2003.104421.0500.HSEAVER@CYBERSHAMANIX.COM>

I hope that those of you building stoves out of tincanium don't fail to check
this site that Chris found for us. And while I realize that tin cans are often
free for the gleaning in trash bins, etc., this is certainly a source if you
wanted greater quantity of various sizes.
And the resealer unit has really got my head buzzing, seems like it would (or
should) somehow be very useful in building stoves if nothing else. I'm wondering
if perhaps it also couldn't be used for putting bottoms on thin stainless
cylinders as well.

--
Harmon Seaver
CyberShamanix
http://www.cybershamanix.com

From das at EAGLE-ACCESS.NET Sat May 3 20:39:48 2003
From: das at EAGLE-ACCESS.NET (Das)
Date: Tue Aug 10 18:30:22 2004
Subject: Pyrolysis v.s. Gasification
Message-ID: <SAT.3.MAY.2003.183948.0600.DAS@EAGLEACCESS.NET>

I disagree.
Pyrolysis is the step of charring regardless of whether or not air is
present.
When biomass is heated at moderate rates the result is roughly 1/3 char,
1/3 condensibles, and 1/3 permanent gases.
A protective cloud of vapors and gases surrounds the fuel particle
preventing direct air contact with the fuel particle until pyrolysis is
nearly complete.
The char does not glow until pyrolysis is finished to the point that air
finally contacts the char.

Observe the burning of a wooden match. The visible flame is the burning of
the pyrolysis cloud. This flame does not touch the surface of the
matchstick.
Burning of the visible flame produces H2O + CO2 + heat
Once the visible flame has passed, then the fully pyrolyzed matchstick char
begins to glow. This is char combustion which produces CO2 + heat.
Pyrolysis and char combustion are the two main reactions which occur in any
solid fueled combustion process.
If the hot combustion products pass through a thick enough bed of char at a
temperature above 700 C, then fuel gas will be produced. This is
gasification. The temperature of the hot combuction gasses (sensible heat
energy) is converted at high efficiency (up to 85% eff) into chemical fuel
energy
heat + CO2 + C ---> 2 CO (Carbon Monoxide)
heat + H2O + C ---> H2 + CO (Hydrogen and Carbon Monoxide)
These gases may be collected, passed through a relatively airtight cool
pipe, then mixed with air and ignited with a potent flame.

The presence or absence of air makes no difference. Pyrolysis is the
charring of the fuel.

A. Das
Original Sources/Biomass Energy Foundation
Box 7137, Boulder, CO 80306
das@eagle-access.net

----------
> From: A.D. Karve <adkarve@PN2.VSNL.NET.IN>
> To: STOVES@LISTSERV.REPP.ORG
> Subject: Re: [STOVES] Pyrolysis v.s. Gasification
> Date: Sunday, April 20, 2003 8:12 PM
>
> Dear Crispin,
> definition is one thing and usage of a word is another. In wood
> gasification, the material to be gasified is ignited, but the oxygen
supply
> is so regulated, that only a part of it burns. The heat generated by the
> burning part of the biomass causes the rest of the biomass to pyrolyse.
> However, because both the processes occur in the same container, the gas
> also contains a lot of nitrogen and carbon monoxide, in addition to the
> distillates of wood. In pyrolysis, the woody material is heated in a
closed
> vessel, without allowing oxygen to enter the vessel. I therefore suggest
> that the two processes should be differentiated not by the presence or
> absence of water, but by the presence or absence of oxygen.
> A.D.Karve
> -----Original Message-----
> From: Crispin <crispin@newdawn.sz>
> To: STOVES@LISTSERV.REPP.ORG <STOVES@LISTSERV.REPP.ORG>
> Date: Sunday, April 20, 2003 2:55 AM
> Subject: [STOVES] Pyrolysis v.s. Gasification
>
>
> >Dear Stovers
> >
> >I am sure this is the right place to ask:
> >
> >>From http://wwwscience.murdoch.edu.au/teach/n210/lects/fuel/biomas2.pdf
> >
> >"Gasification: partial combustion of wood in presence of steam to give a
> >mixture of CO2, CO and H2
> >Pyrolysis: heating of biomass in absence of O2 to give solid char,
liquid
> >distillate and gases."
> >
> >I have seen several references to 'pyrolysis fronts' and gasification.
Is
> >there general agreement on the above definitions?
> >
> >It seems to me that with real wood containing water, there is a presence
of
> >steam. Is this enough steam to qualify for a true 'gasification'
process
> in
> >a wood burning stove with inadequate primary air for full combustion?
What
> >would the liquid distillates be in the absence of steam?
> >
> >There is even talk of "fast pyrolysis".
> >
> >I am getting more confused the more I read.
> >
> >Regards
> >Crispin
> >

From tmiles at TRMILES.COM Sun May 4 03:14:30 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:22 2004
Subject: Draft Spanglish Stoves Site
Message-ID: <SUN.4.MAY.2003.001430.0700.TMILES@TRMILES.COM>

Rogerio, Roberto, Fernando, Don, Lisa, Stuart and others,

I've created a very rough draft for a Spanish-Portuguese Stoves site that is
now in "Spanglish" at:

http://www.repp.org/discussiongroups/resources/estufas/

When it is futher along I'll link it to the main stoves site. For now I
would appreciate original Spanish or Portuguese contributions, translations
or suggestions for the site. I can receive files both via email or FTP.

I do not think that it needs to be a copy of the main site, rather it should
serve those who are developing and promoting stoves in Spanish and
Portuguese speaking areas. It should serve both the Stoves and Bioenergia-L
lists. So let me know what should be on the site and we can shape it as we
go.

Tom Miles

From tombreed at ATTBI.COM Sun May 4 00:48:31 2003
From: tombreed at ATTBI.COM (Tom Reed)
Date: Tue Aug 10 18:30:22 2004
Subject: Pyrolysis v.s. Gasification
Message-ID: <SAT.3.MAY.2003.224831.0600.TOMBREED@ATTBI.COM>

Dear Das:

I agree with YOUR definition, but there's lots of confusion out there. We
need new definitions to form a "tree" of various kinds of pyrolysis as they
occur in various processes, based on the source of heat.

PYROLYSIS
Indirect heat Pyrolysis (in a retort etc.)
Flaming combustion pyrolysis (as in the burning match with excess air or
the downdraft gasifiers with excess fuel)
Superheated steam pyrolysis (hard to reach 300-400 C with superheated
steam...)
Autopyrolysis (self heating after a temperature of 300C is reached with
various heat sources)

Any others???

TOM REED BEF

Dr. Thomas B. Reed
1810 Smith Rd., Golden, CO 80401
tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
----- Original Message -----
From: "Das" <das@EAGLE-ACCESS.NET>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Saturday, May 03, 2003 6:39 PM
Subject: Re: [STOVES] Pyrolysis v.s. Gasification

> I disagree.
> Pyrolysis is the step of charring regardless of whether or not air is
> present.
> When biomass is heated at moderate rates the result is roughly 1/3 char,
> 1/3 condensibles, and 1/3 permanent gases.
> A protective cloud of vapors and gases surrounds the fuel particle
> preventing direct air contact with the fuel particle until pyrolysis is
> nearly complete.
> The char does not glow until pyrolysis is finished to the point that air
> finally contacts the char.
>
> Observe the burning of a wooden match. The visible flame is the burning
of
> the pyrolysis cloud. This flame does not touch the surface of the
> matchstick.
> Burning of the visible flame produces H2O + CO2 + heat
> Once the visible flame has passed, then the fully pyrolyzed matchstick
char
> begins to glow. This is char combustion which produces CO2 + heat.
> Pyrolysis and char combustion are the two main reactions which occur in
any
> solid fueled combustion process.
> If the hot combustion products pass through a thick enough bed of char at
a
> temperature above 700 C, then fuel gas will be produced. This is
> gasification. The temperature of the hot combuction gasses (sensible heat
> energy) is converted at high efficiency (up to 85% eff) into chemical fuel
> energy
> heat + CO2 + C ---> 2 CO (Carbon Monoxide)
> heat + H2O + C ---> H2 + CO (Hydrogen and Carbon Monoxide)
> These gases may be collected, passed through a relatively airtight cool
> pipe, then mixed with air and ignited with a potent flame.
>
> The presence or absence of air makes no difference. Pyrolysis is the
> charring of the fuel.
>
> A. Das
> Original Sources/Biomass Energy Foundation
> Box 7137, Boulder, CO 80306
> das@eagle-access.net
>
> ----------
> > From: A.D. Karve <adkarve@PN2.VSNL.NET.IN>
> > To: STOVES@LISTSERV.REPP.ORG
> > Subject: Re: [STOVES] Pyrolysis v.s. Gasification
> > Date: Sunday, April 20, 2003 8:12 PM
> >
> > Dear Crispin,
> > definition is one thing and usage of a word is another. In wood
> > gasification, the material to be gasified is ignited, but the oxygen
> supply
> > is so regulated, that only a part of it burns. The heat generated by the
> > burning part of the biomass causes the rest of the biomass to pyrolyse.
> > However, because both the processes occur in the same container, the gas
> > also contains a lot of nitrogen and carbon monoxide, in addition to the
> > distillates of wood. In pyrolysis, the woody material is heated in a
> closed
> > vessel, without allowing oxygen to enter the vessel. I therefore suggest
> > that the two processes should be differentiated not by the presence or
> > absence of water, but by the presence or absence of oxygen.
> > A.D.Karve
> > -----Original Message-----
> > From: Crispin <crispin@newdawn.sz>
> > To: STOVES@LISTSERV.REPP.ORG <STOVES@LISTSERV.REPP.ORG>
> > Date: Sunday, April 20, 2003 2:55 AM
> > Subject: [STOVES] Pyrolysis v.s. Gasification
> >
> >
> > >Dear Stovers
> > >
> > >I am sure this is the right place to ask:
> > >
> > >>From
http://wwwscience.murdoch.edu.au/teach/n210/lects/fuel/biomas2.pdf
> > >
> > >"Gasification: partial combustion of wood in presence of steam to give
a
> > >mixture of CO2, CO and H2
> > >Pyrolysis: heating of biomass in absence of O2 to give solid char,
> liquid
> > >distillate and gases."
> > >
> > >I have seen several references to 'pyrolysis fronts' and gasification.
> Is
> > >there general agreement on the above definitions?
> > >
> > >It seems to me that with real wood containing water, there is a
presence
> of
> > >steam. Is this enough steam to qualify for a true 'gasification'
> process
> > in
> > >a wood burning stove with inadequate primary air for full combustion?
> What
> > >would the liquid distillates be in the absence of steam?
> > >
> > >There is even talk of "fast pyrolysis".
> > >
> > >I am getting more confused the more I read.
> > >
> > >Regards
> > >Crispin
> > >

From tombreed at ATTBI.COM Sun May 4 01:04:55 2003
From: tombreed at ATTBI.COM (Tom Reed)
Date: Tue Aug 10 18:30:22 2004
Subject: Great grates? - Tom M
Message-ID: <SAT.3.MAY.2003.230455.0600.TOMBREED@ATTBI.COM>

Dear Tom Miles and all you stovers:

Cooking stoves burn all kinds of fuel including charcoal, like it or not.

The "charcoal grate" is great with air underneath ( ; - / ), but air
supply is critical. If char production exceeds char consumption it will
continue to grow and eventually extinguish the stove; if char consumption
exceeds consumption, it won't form. So, CONTROLLABLE air under the grate
can enable the user to add the heat of charcoal to that of the flaming
pyrolysis.

Agua Das's bronze melting gasifier solves this with a simple valve.

TOM REED

Dr. Thomas B. Reed
1810 Smith Rd., Golden, CO 80401
tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
----- Original Message -----
From: "Tom Miles" <tmiles@TRMILES.COM>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Thursday, May 01, 2003 1:05 PM
Subject: Re: [STOVES] Great grates? - Tom M

> Crispin,
>
> I think it was a good idea. After a while you probably get a bed of coals
> that fills the floor of the Maendeleo and the effect of the shelf probably
> disappears. I wonder if anyone has put holes for combustion air below the
> shelf.
>
> It seems like there might be some small variations like that which would
> improve the efficiency while preserving portability, simplicity and other
> attributes of the Maendaleo design.
>
> Tom
>
>
> On Wed, 30 Apr 2003 11:09:03 +0200, Crispin <crispin@NEWDAWN.SZ> wrote:
>
> >Dear Tom
> >
> >The point of the Maendeleo stove floor shape was raised at at the
> >Vereeniging conference. Apparently they sometimes put a narrow clay
shelf
> >across the _front_ to hold the fuel up off the floor of coals slightly.
> >This is not an approximation of the layout of a Rocket but it does keep
> the
> >wood off the cold floor when starting off. It seems like a good idea.
> >
> >Regards
> >Crispin
> >
>

From elk at WANANCHI.COM Thu May 8 06:23:55 2003
From: elk at WANANCHI.COM (elk)
Date: Tue Aug 10 18:30:22 2004
Subject: Charcoal Briquettes from Sugarcane Bagasse: Making 'CaneCoal' in
Western Kenya
Message-ID: <THU.8.MAY.2003.132355.0300.ELK@WANANCHI.COM>

Fellow stovers;

Pass out the cigars- it's a Success! Chardust's new plant at the Chemelil
Sugar Factory in Western Kenya has now been commissioned & we've begun
commercial sales of 'CaneCoal' - charcoal briquettes made from carbonised
bagasse.

Though it may be premature to call the project a full success just yet-
before we start turning a profit and prove replicability & that such an
investment can be repaid in good time (DFID has help fund this prototype)-
the market reaction is very good and the product is excellent. We may soon
be able to state categorically that CaneCoal is preferred to regular
charcoal in Western Kenya. Our retail prices are equal or lower than lump
wood charcoal retailed at the roadside, so we're competitive on price.

I'm surprised at the quality of the briquette- specially the ash level-
considering it's made of fibres from the stem of tall 'grass'. CaneCoal
lights easily, burns slightly longer than regular charcoal, is hard enough
to be transportable (though significantly more fragile than regular
charcoal), and has surprisingly low ash The ash level, at 12.5% for pure
carbonised bagasse, is low enough to allow us to add some clay to improve
hardness and burn duration.

We employed a professional market research group to survey the domestic
charcoal consumer, and the results were not surprising. The preferred
characteristics of charcoal are density (weight of individual lumps), how
fast it lights, how long it burns, it's compact size and how hard it is.
What is NOT liked about charcoal is smoke, sparks, smell, excessive heat in
the kitchen, and the threat of carbon monoxide (schools teach about this).
As you can infer- the quality of Kenya's artisanally produced charcoal is
variable, with poorly carbonised material producing the smell smoke &
sparks. Pure carbon burns cleanly. We were told that a dull sheen- as
opposed to shiny- is sought after as an indicator of good quality.

CaneCoal doesn't smell (other than a whiff of burnt sugar at ignition from
the molasses added as one of the binders), does not spark at all, and
produces no smoke. Density is almost exactly the same as good quality
charcoal.... and of course it's got a dull sheen. Our briquette size-
cylindrical; averaging 7cm long by 3cm dia., was considered 'perfect' for
the domestic charcoal Jiko. The size of lumps in wood charcoal varies
tremendously & larger pieces must be broken up by hand.

The last 10 CaneCoal burn trials using 1kg fuel in a Kenya Ceramic Jiko with
2 L. water in an open alu. pot average out to the following:

CaneCoal
----------
Time from lighting to boiling: 15.6 min.
Duration from lighting to end of simmering: 173 min. (range 167 to 215)
Water loss from lighting to end of simmering: 2462 grams
Residual ash: 16%
Hardness- % powder + dust + chips under 2cm dia. after dropping from 2m
onto concrete: 28%

By way of comparison......

Regular lump wood charcoal
-----------
Time from lighting to boiling: 22.0 min.
Duration from lighting to end of simmering: 159 min. (range 75 to 220 min)
Water loss from lighting to end of simmering: 2531 grams
Residual ash: 7.5%
Hardness- % powder + dust + chips under 2cm dia. after dropping from 2m
onto concrete: 17%

So, in comparison to the market standard, we lose on hardness (& will
continue trying to improve on that), evaporate less water (slightly lower
calorific value), and produce higher ash- a burn retardant. We are superior
on ignition, smoke, spark, smell, size and burn duration. There's a slight
negative on handling, as Canecoal has more surface dust than lump charcoal.

Overall, I reckon that leaves us on the plus side & allows us to compete
head-to-head with traditional charcoal, though there's a lot of marketing
work to be done. Introducing a new product to replace an old staple is
always a challenge in Africa. We plan to include demonstrations (roadshows)
at markets soon.

Our current rainy season has introduced a challenging production
bottle-neck though, which is how to dry a sufficient quantity of bagasse
from 50% to below 20% moisture level in the absence of much sun. We pump hot
air salvaged from our carbonisers through the perforated floor of a 40 ft
shipping container (fitted with extractor fans) to expedite drying, but this
doesn't keep up with our 15t/day requirement of bulky dry bagasse. We may
have to focus on double shifts during the dry seasons, which fortunately
comprise about 9 months of the year.

I'll update as we progress from here.

rgds;
elk

--------------------------
Elsen L. Karstad
elk@wananchi.com
www.chardust.com
Nairobi Kenya

From mantal at HAWAII.EDU Thu May 8 14:46:42 2003
From: mantal at HAWAII.EDU (Michael J. Antal, Jr.)
Date: Tue Aug 10 18:30:22 2004
Subject: congratulations!
In-Reply-To: <004801c3154c$1c747d80$0647083e@dell>
Message-ID: <THU.8.MAY.2003.084642.1000.MANTAL@HAWAII.EDU>

Dear elk: congratulations! Biocarbons are the fuel of the future. Best
regards, Michael Antal.

-----Original Message-----
From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On
Behalf Of elk
Sent: Thursday, May 08, 2003 12:24 AM
To: STOVES@LISTSERV.REPP.ORG
Subject: [STOVES] Charcoal Briquettes from Sugarcane Bagasse: Making
'CaneCoal' in Western Kenya

Fellow stovers;

The last 10 CaneCoal burn trials using 1kg fuel in a Kenya Ceramic Jiko with
2 L. water in an open alu. pot average out to the following:

By way of comparison......

I'll update as we progress from here.

rgds;
elk

--------------------------
Elsen L. Karstad
elk@wananchi.com
www.chardust.com
Nairobi Kenya

From mantal at HAWAII.EDU Thu May 8 23:13:54 2003
From: mantal at HAWAII.EDU (Michael J. Antal, Jr.)
Date: Tue Aug 10 18:30:22 2004
Subject: charcoal CV
In-Reply-To: <005801c315d1$634329c0$c281fd0c@TOMBREED>
Message-ID: <THU.8.MAY.2003.171354.1000.MANTAL@HAWAII.EDU>

Hi Tom: just a brief note to alert you to our first full length paper on
flash carbonization that is now in press in Ind. Eng. Chem. Res. In this
paper you will be pleased to see that charcoal produced by flash
carbonization retains as much as 66% of the energy contained in the biomass
feedstock. This is one of many reasons why I am sure that charcoal is the
"fuel of the future". I will be glad to distribute this paper by e-mail
after it appears in print. Best regards, Michael.

-----Original Message-----
From: Tom Reed [mailto:tombreed@attbi.com]
Sent: Thursday, May 08, 2003 4:19 PM
To: Michael J. Antal, Jr.
Subject: Re: [STOVES] congratulations!

Dear Stoves and Gasifiers:

Antal's congratulations to ELK on his char pellets are certainly in order.
Charcoal is indeed an amazing and clean fuel and civilization would not have
developed without it.

However, when you make charcoal you trade clean heat for >60% of the energy
contained in the volatiles.

Another alternative is torrefaction which gives almost as clean a fuel for
only a 5-10% energy loss.

Another alternative is densification. Sometimes the larger pellets burn
almost as clean as charcoal and retain all the original energy.

Onward, TOM REED BEF GASIFICATION

Dr. Thomas B. Reed
1810 Smith Rd., Golden, CO 80401
tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
----- Original Message -----
From: "Michael J. Antal, Jr." <mantal@HAWAII.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Thursday, May 08, 2003 12:46 PM
Subject: [STOVES] congratulations!

> Dear elk: congratulations! Biocarbons are the fuel of the future. Best
> regards, Michael Antal.
>
> -----Original Message-----
> From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On
> Behalf Of elk
> Sent: Thursday, May 08, 2003 12:24 AM
> To: STOVES@LISTSERV.REPP.ORG
> Subject: [STOVES] Charcoal Briquettes from Sugarcane Bagasse: Making
> 'CaneCoal' in Western Kenya
>
>
> Fellow stovers;
>
> Pass out the cigars- it's a Success! Chardust's new plant at the Chemelil
> Sugar Factory in Western Kenya has now been commissioned & we've begun
> commercial sales of 'CaneCoal' - charcoal briquettes made from carbonised
> bagasse.
>
> Though it may be premature to call the project a full success just yet-
> before we start turning a profit and prove replicability & that such an
> investment can be repaid in good time (DFID has help fund this prototype)-
> the market reaction is very good and the product is excellent. We may soon
> be able to state categorically that CaneCoal is preferred to regular
> charcoal in Western Kenya. Our retail prices are equal or lower than lump
> wood charcoal retailed at the roadside, so we're competitive on price.
>
> I'm surprised at the quality of the briquette- specially the ash level-
> considering it's made of fibres from the stem of tall 'grass'. CaneCoal
> lights easily, burns slightly longer than regular charcoal, is hard enough
> to be transportable (though significantly more fragile than regular
> charcoal), and has surprisingly low ash The ash level, at 12.5% for pure
> carbonised bagasse, is low enough to allow us to add some clay to improve
> hardness and burn duration.
>
> We employed a professional market research group to survey the domestic
> charcoal consumer, and the results were not surprising. The preferred
> characteristics of charcoal are density (weight of individual lumps), how
> fast it lights, how long it burns, it's compact size and how hard it is.
> What is NOT liked about charcoal is smoke, sparks, smell, excessive heat
in
> the kitchen, and the threat of carbon monoxide (schools teach about this).
> As you can infer- the quality of Kenya's artisanally produced charcoal is
> variable, with poorly carbonised material producing the smell smoke &
> sparks. Pure carbon burns cleanly. We were told that a dull sheen- as
> opposed to shiny- is sought after as an indicator of good quality.
>
> CaneCoal doesn't smell (other than a whiff of burnt sugar at ignition from
> the molasses added as one of the binders), does not spark at all, and
> produces no smoke. Density is almost exactly the same as good quality
> charcoal.... and of course it's got a dull sheen. Our briquette size-
> cylindrical; averaging 7cm long by 3cm dia., was considered 'perfect' for
> the domestic charcoal Jiko. The size of lumps in wood charcoal varies
> tremendously & larger pieces must be broken up by hand.
>
> The last 10 CaneCoal burn trials using 1kg fuel in a Kenya Ceramic Jiko
with
> 2 L. water in an open alu. pot average out to the following:
>
>
> CaneCoal
> ----------
> Time from lighting to boiling: 15.6 min.
> Duration from lighting to end of simmering: 173 min. (range 167 to 215)
> Water loss from lighting to end of simmering: 2462 grams
> Residual ash: 16%
> Hardness- % powder + dust + chips under 2cm dia. after dropping from 2m
> onto concrete: 28%
>
> By way of comparison......
>
> Regular lump wood charcoal
> -----------
> Time from lighting to boiling: 22.0 min.
> Duration from lighting to end of simmering: 159 min. (range 75 to 220 min)
> Water loss from lighting to end of simmering: 2531 grams
> Residual ash: 7.5%
> Hardness- % powder + dust + chips under 2cm dia. after dropping from 2m
> onto concrete: 17%
>
> So, in comparison to the market standard, we lose on hardness (& will
> continue trying to improve on that), evaporate less water (slightly lower
> calorific value), and produce higher ash- a burn retardant. We are
superior
> on ignition, smoke, spark, smell, size and burn duration. There's a slight
> negative on handling, as Canecoal has more surface dust than lump
charcoal.
>
> Overall, I reckon that leaves us on the plus side & allows us to compete
> head-to-head with traditional charcoal, though there's a lot of marketing
> work to be done. Introducing a new product to replace an old staple is
> always a challenge in Africa. We plan to include demonstrations
(roadshows)
> at markets soon.
>
> Our current rainy season has introduced a challenging production
> bottle-neck though, which is how to dry a sufficient quantity of bagasse
> from 50% to below 20% moisture level in the absence of much sun. We pump
hot
> air salvaged from our carbonisers through the perforated floor of a 40 ft
> shipping container (fitted with extractor fans) to expedite drying, but
this
> doesn't keep up with our 15t/day requirement of bulky dry bagasse. We may
> have to focus on double shifts during the dry seasons, which fortunately
> comprise about 9 months of the year.
>
> I'll update as we progress from here.
>
> rgds;
> elk
>
>
>
> --------------------------
> Elsen L. Karstad
> elk@wananchi.com
> www.chardust.com
> Nairobi Kenya
>

From rdboyt at YAHOO.COM Fri May 9 10:28:50 2003
From: rdboyt at YAHOO.COM (Richard Boyt)
Date: Tue Aug 10 18:30:22 2004
Subject: Ceramics for Stoves Part 1- Finding Clay
Message-ID: <FRI.9.MAY.2003.072850.0700.RDBOYT@YAHOO.COM>

Hello stovers.

Greetings from Pottershop Hollow. I strongly believe
that there is a need for knowledge on the design of
low cost, efficient stoves that can be constructed and
used in third world countries. The use of ceramic
materials, and particularly clays show great promise
as a material for use in these stoves.

During the past several years, Libby and I have
searched our tree farm for the location of a clay
deposit that was used by local pioneer potters who
gave our valley its name. We have located clay from a
dozen sites near the scattered remains of a primitive
wood-fired salt kiln and while we have not found the
original clay pit we have found several deposits that
may prove useful in our attempts to explore designs
for very low tech, primitive stoves. This message is
the first of several entries I hope to make on the
work we have done on the use of ceramics for stoves.

We have found that clay of some sort can be found
almost anywhere. However, finding clay that will meet
stove construction requirements is demanding.
Ideally, it should be easy to dig and to separate from
other unwanted materials, e.g., sand, gravel, roots,
leaves, and the like. An ideal clay would be quite
plastic when moist, would dry and fire with a minimum
shrinkage, would fire successfully to high
temperatures and should retain its strength and
integrity when subjected to repeated severe thermal
shock. That's a lot to ask and even in the finest
commercially available clays, the combination of these
traits is a compromise.

We have found that the most promising places to find
clay are in exposed ditches, the banks and bottoms of
ponds, road cuts, excavated foundations, exposed roots
of blown down trees, and the subsoil of marshy, poorly
drained areas.

A spade, pick ax, and a small soil auger are useful in
securing samples that can be tested. While it is
satisfying to find your own clay, you can save a lot
of time and effort by making friends with local
potters. They can tell you where to dig or to buy the
clay they use. Ceramic supply outlets are also very
helpful in sharing information on the clays they sell.
One fine source is:
L & R Specialities, Inc
202 East Mt. Vernon
P.O. Box 309
Nixa, MO 65714
claydogs@aol.com
www.claydogs.com
417-725-2606 (phone) 417-725-2687 (fax).

However, my principal interest here is in presenting
information that might prove useful in areas far from
the advantages of the modern western world.

The next entry, part 2, is intended to discuss testing
locally found clays that can be used in stove
construction.. Hope this will be useful to someone.

Dick Boyt
rdboyt@yahoo.com
20479 Panda Rd
Neosho, MO 64850

__________________________________
Do you Yahoo!?
The New Yahoo! Search - Faster. Easier. Bingo.
http://search.yahoo.com

From tmiles at TRMILES.COM Fri May 9 14:10:09 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:22 2004
Subject: Charcoal Briquettes from Sugarcane Bagasse: Making 'CaneCoal'
in Western Kenya
Message-ID: <FRI.9.MAY.2003.141009.0400.TMILES@TRMILES.COM>

Pictures of Elk's CANECOAL, the sugar mill, and his production facility
can be found on the stoves website along with a related article from the
Village Power Newsletter.

http://www.repp.org/discussiongroups/resources/stoves/

At the European Thermonet conference in Florence last month Daey Owens
told us about Mike Antal's upcoming paper on carbonization. We all look
forward to its publication.

Tom Miles

From tmiles at TRMILES.COM Sat May 10 17:44:23 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:22 2004
Subject: Biomass Cookstoves Weblog 5/10/2003
Message-ID: <SAT.10.MAY.2003.144423.0700.TMILES@TRMILES.COM>

This week on the Biomass Cookstoves website:
http://www.repp.org/discussiongroups/resources/stoves/

Elsen Karstad from Nairobi shows us his Canecoal, charcoal made from waste
bagasse from a sugar mill.

Rogerio C de Miranda shows us how the Ecostove has been used to modernize
small enterprises in Nicaragua.

Several additions were made to Cocinas y Estufas Mejoradas:
http://www.repp.org/discussiongroups/resources/estufas/
A list of technical terms was started in a "Lexico Tecnico" to show terms
used in different regions and countries. Information like this together with
the construction guides can help volunteers working on stove projects.
Roberto Escardo is leading a Spanish editorial group to develop and improve
the site.

I was asked last week by a volunteer looking for a stoves project who to
contact in Guatemala so that she could join a project while she is there
practicing Spanish. I found that it is not clear from our websites who you
contact for this information. If each of the oganizations will provide me
with contact information for each of their project locations I will develp a
contact list for volunteers.

Tom Miles

From tmiles at TRMILES.COM Sun May 11 19:35:05 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:22 2004
Subject: Intl Seminar on Bioenergy Mexico June 26-28, 2003
Message-ID: <SUN.11.MAY.2003.163505.0700.TMILES@TRMILES.COM>

LAMNET (Latin American Thematic Network on Bioenergy) is hosting it's Fifth
Workshop: International Seminar on Bioenergy and Sustainable Rural
Development in Morelia, M?xico 26/06/2003 - 28/06/2003

Information at:

LAMNET - http://www.bioenergy-lamnet.org/

STOVES -
http://www.repp.org/discussiongroups/resources/stoves/LAMNET/Mexmorel.htm

Thanks to Jeremy Foster for passing this along.

From dstill at EPUD.NET Mon May 12 04:23:33 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:22 2004
Subject: Heat lost into body of combustion chamber
Message-ID: <MON.12.MAY.2003.012333.0700.DSTILL@EPUD.NET>

Dr. Dale Andreatta has answered a question that has been of great interest
to a lot of us at Aprovecho: How much heat is lost into the body of the
combustion chamber ? Is the amount of heat lost determined by materials used
to make the combustion chamber? Here is his report to ETHOS.

Best,

Dean Still
May 8, 2003

Introduction and Background

This report seeks to answer the following questions:

What would be the heat loss for a stove made of the following materials.

1. Cast iron

2. Building bricks

3. Cement

4. Clay

5. Thick clay

6. Basic lorena material and design

7. Lorena but lined with sawdust/clay blocks

8. I?ve also looked at the question of thin insulative bricks surrounded by
very good insulator (wood ash) vs. insulative bricks with just air vs.
insulative bricks with poor insulator. In other words, is the extra effort
of adding the wood ash worthwhile.

All calculations here assume the same conditions as previous calculations,
namely a stove that is 0.1178 square meters in internal surface area with
gas that is 700? C hotter than the surroundings. A one-hour cook time is
assumed. The 0.1178 square meters is the area of a 12-inch long 5-inch
diameter tube, a typical rocket size. ( A Rocket stove would use
approximately 1 kilo of wood or about 19 MJ per hour to create these
conditions. Dean Still)

Results

Cast Iron

Regarding the cast iron, the work I?ve done calculating the heat loss really
applies to fairly insulative materials, while cast iron would be a good
conductor. It would take a while to figure out the cast iron heat loss
properly, but a quick calculation says it would be about 6 MJ.

Ordinary Bricks

Regarding ordinary building bricks, if the bricks were about 8 cm thick, the
heat loss would be about 5.4 MJ. The heat loss is similar to that of cast
iron, but the reason for the heat loss is different. In the case of the
cast iron, the outer surface would heat up quickly and much heat would be
lost from the outside of the stove, mostly by radiation, while for the heavy
brick stove, the outside doesn?t heat up much even after an hour, and most
of the heat goes into warming the stove body. Thinner bricks would probably
loose a little less heat, but not a lot less.

Concrete

Regarding a concrete stove, I assumed properties of density =2300, specific
heat = 880, conductivity = 1, which are numbers I got out of a textbook.
For a 3-cm thick stove, the heat loss is about 7.8 MJ, with about half of
the heat being lost into the surroundings and half going into the body of
the stove. The calculations were also done for 8 cm-thick walls, in which
case 8.0 MJ was lost, almost all into the stove body. For thick walled
stoves, the bulk of the energy always goes into warming the stove body.

Clay

Regarding clay stoves of various thicknesses, I could find properties of
clay in a book, but I think this is the form of wet clay that comes out of
the ground. I assume one would make a stove of vitrified clay. Roberto
Escardo recently sent a message with some properties of terrazzo floor,
which I?m going to assume is a vitrified clay product, and use its
properties. I used conductivity = 0.41, density = 1500, and specific heat =
880 (for clay).

The heat loss for 3-cm thick walls is 4.2 MJ, with about half of the heat
retained in the body and about half lost into the environment. For 8-cm
thick and greater, the loss is about 4.1 MJ, with the bulk of the heat
retained in the stove body. For body thickness between 3 and 8 cm, the heat
loss is a little less, but not a lot less.

Lorena material

Regarding the lorena, I am again having trouble finding good data. For
soils and sand-type materials, I find in the tables a huge range of values
for thermal conductivity, and the main variable seems to be moisture. One
reference gives dry soil conductivity as 0.064 and wet as 0.54, nearly a
10:1 range. Another reference gives dry soil as 0.13 and wet as 1.07, again
nearly a 10:1 ratio. The same reference gives dry sand as 0.13. Roberto
Escardo?s recent posting gives dry compacted soil with a conductivity of
0.75. All these are in metric units.

Assuming density = 1500 (dry packed soil), specific heat = 1840 (dry packed
soil), and conductivity = 0.13 (this is about as low as it could possibly
be) assuming a surface area of 0.1178 square meters, and assuming 8-cm thick
walls, the heat loss is 3.4 MJ. If you redo the calculations with double
the conductivity (accounting perhaps for the material being a bit damp) you
get a heat loss of 4.8 MJ. Note that this calculation is probably low since
the actual conductivity is probably higher, and because the actual inside
area of a Lorena stove would typically be a good bit larger than was assumed
here.

Lined lorena

What if you lined a Lorena with an inch (2.5 cm) of the insulative
sawdust/clay mixture that I tested? Its properties are density = 729,
specific heat = 701, conductivity = 0.081. The heat loss is reduced from
3.4 MJ to 1.27 MJ. All of the heat goes into the body of the stove, and the
outer part is barely beginning to warm up. Again this is based on 0.1178
square meters of area, if the actual area is larger, increase the heat loss
appropriately.

Same inside layer, variable outside layer

Finally, if you take a 1 inch (25 mm) layer of sawdust/clay and look at the
effect of what is outside this layer, you might consider 3 cases.

Case 1: Heavy soil/sand/lorena material on the outside. This was
calculated above, and the loss is 1.27 MJ.

Case 2: Really good insulator like wood ash outside the sawdust/clay. Here
the heat loss is 1.13 MJ. The assumed properties of wood ash are density =
200, specific heat = 1000, conductivity = 0.0311.

Case 3: Just air outside the primary insulation. Here the heat loss is
1.33 MJ.

Thus, if the first inch of solid material is a good insulator, it doesn?t
matter much what is outside it.

From tombreed at ATTBI.COM Tue May 13 07:53:48 2003
From: tombreed at ATTBI.COM (Tom Reed)
Date: Tue Aug 10 18:30:22 2004
Subject: Status of WoodGas CampStoves
Message-ID: <TUE.13.MAY.2003.055348.0600.TOMBREED@ATTBI.COM>

Dear Dean:

I talked to Ron last week and will equip him with our latest stove and
manual.

We have changed the name from "Turbo" stove to "WoodGas stove". Turbo sort
of belongs to our former sponsors, Community Power Corporation, CPC. They
are focusing all their attention on small power biomass gasification systems
now. Maybe Aprovecho will eventually get one to use your scrap wood to
supply all your power. See www.gocpc.com

Sorry I won't be there... Family calls. Your pal, TOM REED
BEF STOVES

Dr. Thomas B. Reed
1810 Smith Rd., Golden, CO 80401
tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
----- Original Message -----
From: "Dean Still" <dstill@epud.net>
To: "Tom Reed" <tombreed@attbi.com>; "Ronal W. Larson" <larcon@sni.net>
Sent: Sunday, May 11, 2003 11:55 PM
Subject: Re: Status of WoodGas CampStoves

> Dear Tom,
>
> Glad that we can test your stove! Can you just give a Turbo to Ron Larson
to
> bring to the Stove Testing Seminar?
>
> Best,
>
> Dean
>
>
>

From rdboyt at YAHOO.COM Tue May 13 15:09:56 2003
From: rdboyt at YAHOO.COM (Richard Boyt)
Date: Tue Aug 10 18:30:22 2004
Subject: Ceramics for Stoves Part 2- Testing Unfired (green) Clay
Message-ID: <TUE.13.MAY.2003.120956.0700.RDBOYT@YAHOO.COM>

Hello stovers.

Greetings from Pottershop Hollow in the SW Missouri
Ozarks where last week tornadoes did their damndest.
Sunday's blow just missed us by a few miles as did the
storms of the rest of the week. Two years ago the
farm got hit by several small tornadoes that uprooted
over a thousand of our larger trees.

Today, there are many fine books and magazines on
contemporary ceramics that describe exciting new
equipment, materials, and techniques. Here, however,
I'm trying to limit discussion to simple,
non-sophisticated, even primitive ceramic procedures
that could be used by third world socities in
constructing stoves.

A quick test for clay plasticity can be made on the
small samples of clay gathered in Part one. First,
remove all obvious stone, gravel, and organic trash.
Then add or remove enough water to bring a fist-sized
sample to the softness and plasticity of Play-Dough.
Squeeze it in your fist so that some of it tries to
squish out between your fingers. When you relax your
fist, a plastic clay should retain its squeezed shape
and not crumble away. Plasticity is good, however,
even less plastic clays may have some use in stove
building, as they may prove to be very refractory.

Why plastic? To be usable, clay must be shaped, then
be strong enough to hold that shape while drying. Why
refractory? It is also important for the clay to
withstand the extremely high temperatures and repeated
thermal shocks it would experience in a stove's
combustion chamber. Clays that are less plastic or
refractory, however may find use in other parts of a
stove that take less heat. A low refractory clay
subjected to excessively high temperatures may bloat,
bubble, slump, or even melt into a puddle.

Refine about half a kilo (one pound) of each of the
two or three most promising clays you have dug.
Remove all obvious foreign matter. Stir in enough
water to turn the sample to a liquid slurry thin
enough to pass through the mesh of a small strainer.
Discard the coarse material that fails to pass. As an
alternative to the use of the strainer, make a very
thin watery slurry of clay, and let it settle for a
few hours, allowing any sand and grit to settle to the
bottom. Carefully pour off the upper layers of clay
and water, and strain them through a thin cloth (such
as cheesecloth) to remove any suspended organic
matter. Next, let the clean strained thin slurry sit
quietly for several days (the longer the better), to
allow the clay to settle out. Carefully pour off the
clear water that rises to the top. The settled clay
is now ready to be dried to a soft, plastic,
non-sticky, moldable consistency. You can achieve
this through a combination of evaporation and
absorption of the excess water. To reach the desired
consistency reasonably quickly, pour the slurry onto
dry Plaster of Paris batts or into plaster bowls you
can make, or pour the slurry onto the surface of dry
newspapers that will gradually absorb the excessive
moisture. This method of using water to seperate
particle sizes is essentially the same as practiced by
Mother Nature to form the clay beds we dig.

When the clays attain a plastic consistency, form from
each sample half a dozen round disks about 1-2mm (1/16
inch) thick, and 2.5 cm (1 inch) in diameter. Imprint
upon the surface of each disk an identifying number
and the the impression of measurement marks of an
embossed plastic ruler. Keep a written record. Dry
the disks slowly to avoid warping or cracking as they
shrink. Cracks at the edges and curling indicate
uneven drying. Drying may be speeded up by placing the
disks between two dry plaster batts or between
weighted multiple sheets of newspaper. If using
newspapers, change the wet sheets, as needed. When
completely dry, re-measure the ruler marks to
determine percentage of drying shrinkage. I have
found that my pottershop clays typically have about a
twelve percent shrinkage. In general, clays made up
of very fine particles tend to be more plastic and
shrink more than clays made up of larger coarse
particles. Shrinkage and low plasticity both can
present problems in forming, drying, and firing the
clay.

I admit that I have seen only a very small part of the
world, but what I have seen in Eastern Europe and
Northwest Africa encourages me to believe that I might
be of some small help in promoting clean burning,
inexpensive, simple, efficient cook stoves. Is only a
little, but with love.

The next entry (Part 3) is intended to discuss methods
of firing local clays for stove construction. Hope
this proves useful.

Dick Boyt
rdboyt@yahoo.com
20479 Panda Rd
Neosho, MO 64850

__________________________________
Do you Yahoo!?
The New Yahoo! Search - Faster. Easier. Bingo.
http://search.yahoo.com

From ventfory at IAFRICA.COM Wed May 14 03:07:30 2003
From: ventfory at IAFRICA.COM (Kobus)
Date: Tue Aug 10 18:30:22 2004
Subject: Ceramics for Stoves Part 2- Testing Unfired (green) Clay
Message-ID: <WED.14.MAY.2003.090730.0200.VENTFORY@IAFRICA.COM>

Dear Richard

You said:

>The next entry (Part 3) is intended to discuss methods
>of firing local clays for stove construction. Hope
>this proves useful.

We here in South Africa are lucky in that we have access to high quality clays and industries that specialize in vacuum-formed ceramic fibre processes. The latter does not come cheap however so I am looking forward to your Part 3. People from the South are listening.

Regards

Kobus
ventfory@iafrica.com

From lanny at ROMAN.NET Wed May 14 18:27:22 2003
From: lanny at ROMAN.NET (Lanny Henson)
Date: Tue Aug 10 18:30:22 2004
Subject: Ceramics for Stoves Part 2- Testing Unfired (green) Clay
Message-ID: <WED.14.MAY.2003.182722.0400.LANNY@ROMAN.NET>

> The next entry (Part 3) is intended to discuss methods
> of firing local clays for stove construction. Hope
> this proves useful.

Richard,
Thanks for the info about clay and firing methods. It is useful. Will you
also be instructing us on kiln construction?
Looking forward to #3
Lanny Henson

----- Original Message -----
From: Richard Boyt <rdboyt@YAHOO.COM>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Tuesday, May 13, 2003 3:09 PM
Subject: [STOVES] Ceramics for Stoves Part 2- Testing Unfired (green) Clay

> Hello stovers.
>
> Greetings from Pottershop Hollow in the SW Missouri
> Ozarks where last week tornadoes did their damndest.
> Sunday's blow just missed us by a few miles as did the
> storms of the rest of the week. Two years ago the
> farm got hit by several small tornadoes that uprooted
> over a thousand of our larger trees.
>
> Today, there are many fine books and magazines on
> contemporary ceramics that describe exciting new
> equipment, materials, and techniques. Here, however,
> I'm trying to limit discussion to simple,
> non-sophisticated, even primitive ceramic procedures
> that could be used by third world socities in
> constructing stoves.
>
> A quick test for clay plasticity can be made on the
> small samples of clay gathered in Part one. First,
> remove all obvious stone, gravel, and organic trash.
> Then add or remove enough water to bring a fist-sized
> sample to the softness and plasticity of Play-Dough.
> Squeeze it in your fist so that some of it tries to
> squish out between your fingers. When you relax your
> fist, a plastic clay should retain its squeezed shape
> and not crumble away. Plasticity is good, however,
> even less plastic clays may have some use in stove
> building, as they may prove to be very refractory.
>
> Why plastic? To be usable, clay must be shaped, then
> be strong enough to hold that shape while drying. Why
> refractory? It is also important for the clay to
> withstand the extremely high temperatures and repeated
> thermal shocks it would experience in a stove's
> combustion chamber. Clays that are less plastic or
> refractory, however may find use in other parts of a
> stove that take less heat. A low refractory clay
> subjected to excessively high temperatures may bloat,
> bubble, slump, or even melt into a puddle.
>
> Refine about half a kilo (one pound) of each of the
> two or three most promising clays you have dug.
> Remove all obvious foreign matter. Stir in enough
> water to turn the sample to a liquid slurry thin
> enough to pass through the mesh of a small strainer.
> Discard the coarse material that fails to pass. As an
> alternative to the use of the strainer, make a very
> thin watery slurry of clay, and let it settle for a
> few hours, allowing any sand and grit to settle to the
> bottom. Carefully pour off the upper layers of clay
> and water, and strain them through a thin cloth (such
> as cheesecloth) to remove any suspended organic
> matter. Next, let the clean strained thin slurry sit
> quietly for several days (the longer the better), to
> allow the clay to settle out. Carefully pour off the
> clear water that rises to the top. The settled clay
> is now ready to be dried to a soft, plastic,
> non-sticky, moldable consistency. You can achieve
> this through a combination of evaporation and
> absorption of the excess water. To reach the desired
> consistency reasonably quickly, pour the slurry onto
> dry Plaster of Paris batts or into plaster bowls you
> can make, or pour the slurry onto the surface of dry
> newspapers that will gradually absorb the excessive
> moisture. This method of using water to seperate
> particle sizes is essentially the same as practiced by
> Mother Nature to form the clay beds we dig.
>
> When the clays attain a plastic consistency, form from
> each sample half a dozen round disks about 1-2mm (1/16
> inch) thick, and 2.5 cm (1 inch) in diameter. Imprint
> upon the surface of each disk an identifying number
> and the the impression of measurement marks of an
> embossed plastic ruler. Keep a written record. Dry
> the disks slowly to avoid warping or cracking as they
> shrink. Cracks at the edges and curling indicate
> uneven drying. Drying may be speeded up by placing the
> disks between two dry plaster batts or between
> weighted multiple sheets of newspaper. If using
> newspapers, change the wet sheets, as needed. When
> completely dry, re-measure the ruler marks to
> determine percentage of drying shrinkage. I have
> found that my pottershop clays typically have about a
> twelve percent shrinkage. In general, clays made up
> of very fine particles tend to be more plastic and
> shrink more than clays made up of larger coarse
> particles. Shrinkage and low plasticity both can
> present problems in forming, drying, and firing the
> clay.
>
> I admit that I have seen only a very small part of the
> world, but what I have seen in Eastern Europe and
> Northwest Africa encourages me to believe that I might
> be of some small help in promoting clean burning,
> inexpensive, simple, efficient cook stoves. Is only a
> little, but with love.
>
> The next entry (Part 3) is intended to discuss methods
> of firing local clays for stove construction. Hope
> this proves useful.
>
> Dick Boyt
> rdboyt@yahoo.com
> 20479 Panda Rd
> Neosho, MO 64850
>
> __________________________________
> Do you Yahoo!?
> The New Yahoo! Search - Faster. Easier. Bingo.
> http://search.yahoo.com
>

From aytash at AYTASH.COM Wed May 14 19:13:48 2003
From: aytash at AYTASH.COM (Mert Aydogdu)
Date: Tue Aug 10 18:30:22 2004
Subject: Gelled Ethanol
Message-ID: <WED.14.MAY.2003.191348.0400.AYTASH@AYTASH.COM>

Hello,

I am the producer of gelled ethanols at turkey. You can visit
www.aytash.com I have 3 formulas and I tested them and with every formula
I suceed to produce gelled ethanols. 1st formula is with carbomer, 2nd is
cellulose and 3rd is calcium acetate. But anyone know what is the formula
of sterno products? Is it have different formula? Also with producing
calcum acetate , after the burning it has chalk (Ca), do anyone have
another formula with producing calcium aceteta? (different ratios?)

Mert Aydogdu
Mobile +90 523 2131117
aytash@aytash.com

From rstanley at LEGACYFOUND.ORG Thu May 15 01:24:16 2003
From: rstanley at LEGACYFOUND.ORG (Richard Stanley)
Date: Tue Aug 10 18:30:22 2004
Subject: Ceramics for Stoves Part 2- Testing Unfired (green) Clay
Message-ID: <THU.15.MAY.2003.082416.0300.>

Richard,

Thanks so much for the information . Your contribution like Lanny's and lots
of others in this newsgroup is unique highly valued. Lots of us are in such
situations now in the developing nations. Maybe some day the newsgroup is
given funds to directly support field sites so that information like this can
find immediate field application where it can be refined and integrated to
local conditions. Thats just a vision I have.
Is it shared out there ?

Richard Stanley

Lanny Henson wrote:

> > The next entry (Part 3) is intended to discuss methods
> > of firing local clays for stove construction. Hope
> > this proves useful.
>
> Richard,
> Thanks for the info about clay and firing methods. It is useful. Will you
> also be instructing us on kiln construction?
> Looking forward to #3
> Lanny Henson
>
> ----- Original Message -----
> From: Richard Boyt <rdboyt@YAHOO.COM>
> To: <STOVES@LISTSERV.REPP.ORG>
> Sent: Tuesday, May 13, 2003 3:09 PM
> Subject: [STOVES] Ceramics for Stoves Part 2- Testing Unfired (green) Clay
>
> > Hello stovers.
> >
> > Greetings from Pottershop Hollow in the SW Missouri
> > Ozarks where last week tornadoes did their damndest.
> > Sunday's blow just missed us by a few miles as did the
> > storms of the rest of the week. Two years ago the
> > farm got hit by several small tornadoes that uprooted
> > over a thousand of our larger trees.
> >
> > Today, there are many fine books and magazines on
> > contemporary ceramics that describe exciting new
> > equipment, materials, and techniques. Here, however,
> > I'm trying to limit discussion to simple,
> > non-sophisticated, even primitive ceramic procedures
> > that could be used by third world socities in
> > constructing stoves.
> >
> > A quick test for clay plasticity can be made on the
> > small samples of clay gathered in Part one. First,
> > remove all obvious stone, gravel, and organic trash.
> > Then add or remove enough water to bring a fist-sized
> > sample to the softness and plasticity of Play-Dough.
> > Squeeze it in your fist so that some of it tries to
> > squish out between your fingers. When you relax your
> > fist, a plastic clay should retain its squeezed shape
> > and not crumble away. Plasticity is good, however,
> > even less plastic clays may have some use in stove
> > building, as they may prove to be very refractory.
> >
> > Why plastic? To be usable, clay must be shaped, then
> > be strong enough to hold that shape while drying. Why
> > refractory? It is also important for the clay to
> > withstand the extremely high temperatures and repeated
> > thermal shocks it would experience in a stove's
> > combustion chamber. Clays that are less plastic or
> > refractory, however may find use in other parts of a
> > stove that take less heat. A low refractory clay
> > subjected to excessively high temperatures may bloat,
> > bubble, slump, or even melt into a puddle.
> >
> > Refine about half a kilo (one pound) of each of the
> > two or three most promising clays you have dug.
> > Remove all obvious foreign matter. Stir in enough
> > water to turn the sample to a liquid slurry thin
> > enough to pass through the mesh of a small strainer.
> > Discard the coarse material that fails to pass. As an
> > alternative to the use of the strainer, make a very
> > thin watery slurry of clay, and let it settle for a
> > few hours, allowing any sand and grit to settle to the
> > bottom. Carefully pour off the upper layers of clay
> > and water, and strain them through a thin cloth (such
> > as cheesecloth) to remove any suspended organic
> > matter. Next, let the clean strained thin slurry sit
> > quietly for several days (the longer the better), to
> > allow the clay to settle out. Carefully pour off the
> > clear water that rises to the top. The settled clay
> > is now ready to be dried to a soft, plastic,
> > non-sticky, moldable consistency. You can achieve
> > this through a combination of evaporation and
> > absorption of the excess water. To reach the desired
> > consistency reasonably quickly, pour the slurry onto
> > dry Plaster of Paris batts or into plaster bowls you
> > can make, or pour the slurry onto the surface of dry
> > newspapers that will gradually absorb the excessive
> > moisture. This method of using water to seperate
> > particle sizes is essentially the same as practiced by
> > Mother Nature to form the clay beds we dig.
> >
> > When the clays attain a plastic consistency, form from
> > each sample half a dozen round disks about 1-2mm (1/16
> > inch) thick, and 2.5 cm (1 inch) in diameter. Imprint
> > upon the surface of each disk an identifying number
> > and the the impression of measurement marks of an
> > embossed plastic ruler. Keep a written record. Dry
> > the disks slowly to avoid warping or cracking as they
> > shrink. Cracks at the edges and curling indicate
> > uneven drying. Drying may be speeded up by placing the
> > disks between two dry plaster batts or between
> > weighted multiple sheets of newspaper. If using
> > newspapers, change the wet sheets, as needed. When
> > completely dry, re-measure the ruler marks to
> > determine percentage of drying shrinkage. I have
> > found that my pottershop clays typically have about a
> > twelve percent shrinkage. In general, clays made up
> > of very fine particles tend to be more plastic and
> > shrink more than clays made up of larger coarse
> > particles. Shrinkage and low plasticity both can
> > present problems in forming, drying, and firing the
> > clay.
> >
> > I admit that I have seen only a very small part of the
> > world, but what I have seen in Eastern Europe and
> > Northwest Africa encourages me to believe that I might
> > be of some small help in promoting clean burning,
> > inexpensive, simple, efficient cook stoves. Is only a
> > little, but with love.
> >
> > The next entry (Part 3) is intended to discuss methods
> > of firing local clays for stove construction. Hope
> > this proves useful.
> >
> > Dick Boyt
> > rdboyt@yahoo.com
> > 20479 Panda Rd
> > Neosho, MO 64850
> >
> > __________________________________
> > Do you Yahoo!?
> > The New Yahoo! Search - Faster. Easier. Bingo.
> > http://search.yahoo.com
> >

From ronallarson at QWEST.NET Thu May 15 10:29:09 2003
From: ronallarson at QWEST.NET (Ron Larson)
Date: Tue Aug 10 18:30:22 2004
Subject: FW: [hedon] Paper on the "Gender-Energy-Poverty Nexus"
Message-ID: <THU.15.MAY.2003.082909.0600.RONALLARSON@QWEST.NET>

Stovers:

I have just read the report cited below and concur with Grant that it is
excellent - and all of us on "stoves" should read it.

The points that stood out for me are:

1. the expressed need for lighting - which we have talked about some but
not enough. I own an antique small kerosene camp-type cookstove with a big
piece of mica that made an attempt. Agua Das has shown me some of his first
attempts with pyrolysis gases feeding a mantle. But we are not working hard
enough on this fundamental desire of our stoves customers for lighting.
Maybe this should be left to the PV people - but that is pretty expensive.

2. The second is how little we know about some fundamental stoves issues.
Here is a quote from the bottom of page 14:

"The table does not however answer the question as to what women themselves
want in terms
of their fuel type and its acquisition. Do women want to continue to use
wood/charcoal, albeit
with more efficient stoves, because it fits with their traditions ? in which
case, what kind of
improvements are needed - or would they prefer to use gas (biogas or LPG) or
electricity
because they value the convenience? Would rural women pay for wood (good
quality, regular
supply, in quantities that matched cash flow) if it relieved them of the
burden of collection
and freed them to participate in income generation, community activities, or
to devote more
time to their families? The answers to these types of questions are
important for the
formulation of policies that address women?s strategic needs, and research
is necessary to find
the answers in a variety of contexts."

The authors of this report do not answer these (because the surveys don't
exist). Anyone on "stoves" able to tell us the answer to these two
important questions in regions where you are working?

3. The authors close this section 6, saying:
"The challenge to the energy profession is evident." - That's us.

4. Their Box #1 on p 18 contains this recommendation:

"Improved technologies for charcoal production can boost sustainability and
incomes."

(which of course resonates with me)

5. On page 20: "Interest in household energy seems to have declined." (I
do see some improvement personally - through the Shell Foundation work
mainly)

6. This 24 page PDF file contains 46 references on 3 pages and can be read
pretty quickly. This is not on stoves - but there are plenty of mentions of
stoves - with a strong emphasis on entrepreneurship roles. More questions
than answers - but we can perhaps help as a group in providing some of the
answers. I hope this "plug" will encourage more dialog on these "soft"
issues. Thanks to Grant for bringing this paper (and the associated web
sites) to our attention.

7. The second paper cited by Grant (257 kB PDF) seems to be a somewhat
earlier version of similar material but with more of a stoves focus. I have
only skimmed this one.

Ron

-----Original Message-----
From: Grant Ballard-Tremeer [mailto:grant@ecoharmony.com]
Sent: Thursday, May 15, 2003 4:49 AM
To: hedon@yahoogroups.com
Subject: [hedon] Paper on the "Gender-Energy-Poverty Nexus"

An excellent paper by Joy Clancy, Margaret Skutsch and Simon Batchelor
which explores the gender-energy-poverty nexus is available for
download on the SPARKNET website at:

www.sparknet.info/goto.php/view/21/file.htm

From lanny at ROMAN.NET Thu May 15 20:04:45 2003
From: lanny at ROMAN.NET (Lanny Henson)
Date: Tue Aug 10 18:30:22 2004
Subject: Using steam to move heat through a stove system.
Message-ID: <THU.15.MAY.2003.200445.0400.LANNY@ROMAN.NET>

Stove Friends,
I noticed Dr Karve uses stem to carry heat to the pots in his very efficient
charcoal stove.
Could there be a use for steam heat in a biomass stoves? Maybe not in a
single pot system but maybe in a stacked pot system? How about stacking
insulated pot shields. Each shield would have two handles and hold a pot in
the best position for flow in a stack. With the handles you could easily
change he order of the stack as necessary.
Lanny Henson

From dstill at EPUD.NET Fri May 16 17:28:18 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:22 2004
Subject: Stove Testing and Design Seminar June 2 to 6
Message-ID: <FRI.16.MAY.2003.142818.0700.DSTILL@EPUD.NET>

Dear Stovers,

Thanks for the interest in the ETHOS Stove Testing and Design Seminar which
is now full with 15 participants. As well as professionals there are
students coming from Iowa State, Colorado State and Berkeley. We will be
testing up to 8 stoves initially including the Jiko, Crispin's stove from
South Africa, Ron Larson is bringing a stove, Tom Reed's newest stove, A
Rocket with new flow path, Paul Anderson's Juntos, Lanny Henderson's stove
and a open fire. After two days of testing for efficiency and CO, we will
break into small working groups and try to improve upon the state of the
art. There will be classes on homemade refractories, gasification, sheet
metal fabrication of prototypes, etc. The handouts will be the first, easy
half of Sam Baldwin's book "Biomass Stoves" and readings on gasification.

We'll report back on our experience...Should be fun! (Larry Winiarski is
working on a hopefully mobile surprise for participants.)

Best,

Dean

From tmiles at TRMILES.COM Sat May 17 01:50:34 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:22 2004
Subject: ARECOP: Wood Gas Stoves and Glow (Feb 2003)
Message-ID: <FRI.16.MAY.2003.225034.0700.TMILES@TRMILES.COM>

Two interesting features are now on the Asian Regional Cookstove Program
website at www.arecop.org

There are pictures from the March 19-21 Regional training on wood gas stove
development and production in Bangkok, Thailand. The focus of the training
was on the study of a wood gas stove - IGS II, an institutional/small
industrial stove, developed by AIT. Other gasifier stoves included:

(a) Semi-gasifier stove with briquette fuel, developed by AIT
(b) Spectra wood gas stove, equipped with blower and fuelled with wood
chips.
Developed by NERD, Sri Lanka.
(c) Viro Stove (semi-gasifier) fuelled with small pieces of wood or paper
briquette.
Developed by New Dawn Engineering, South Africa.
(d) Semi gasifier stove, fuelled with wood chips, earlier developed by
Z-mart stove, USA and modified by Dian Desa, Indonesia.

The February 2003 edition of GLOW magazine (Vol 29) features Improved
Cookstoves, Indoor air pollution and health.

Tom Miles

From ronallarson at QWEST.NET Sat May 17 10:37:47 2003
From: ronallarson at QWEST.NET (Ron Larson)
Date: Tue Aug 10 18:30:22 2004
Subject: ARECOP: Wood Gas Stoves and Glow (Feb 2003)
In-Reply-To: <200305170511.h4H5Bkf30340@ns1.repp.org>
Message-ID: <SAT.17.MAY.2003.083747.0600.RONALLARSON@QWEST.NET>

Stovers:

1. I went to the www.arecop.org site and was again impressed.

2. In "Glow", the lead editorial was half by Auke Koopmans who regularly
contributes here. There is considerable new health data of the type often
reported by Kirk Smith (whose "Science" editorial is reprinted here).

3. I am writing to see if we could have more information on a stove
preference survey technique that was written up there by KIRAN DHANAPALA,
apparently of the University of West Virginia in Morgantown WV. He may also
have been at the Pune stove conference. Anyone have his e-mail?

4. What I like is that he reports on a survey technique from which one can
deduce willingness to pay for improved stoves. I didn't see any results -
only a methodology. His references are missing in "Glow". Anyone ever used
this technique? This might be something worth standardizing on.

Ron

>-----Original Message-----
>From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On
>Behalf Of Tom Miles
>Sent: Friday, May 16, 2003 11:51 PM
>To: STOVES@LISTSERV.REPP.ORG
>Subject: ARECOP: Wood Gas Stoves and Glow (Feb 2003)
>
>
>---------------------- Information from the mail header
>-----------------------
>Sender: The Stoves Discussion List <STOVES@LISTSERV.REPP.ORG>
>Poster: Tom Miles <tmiles@TRMILES.COM>
>Subject: ARECOP: Wood Gas Stoves and Glow (Feb 2003)
>-------------------------------------------------------------------
>------------
>
>Two interesting features are now on the Asian Regional Cookstove Program
>website at www.arecop.org
>
>There are pictures from the March 19-21 Regional training on wood gas stove
>development and production in Bangkok, Thailand. The focus of the training
>was on the study of a wood gas stove - IGS II, an institutional/small
>industrial stove, developed by AIT. Other gasifier stoves included:
>
>(a) Semi-gasifier stove with briquette fuel, developed by AIT
>(b) Spectra wood gas stove, equipped with blower and fuelled with wood
>chips.
> Developed by NERD, Sri Lanka.
>(c) Viro Stove (semi-gasifier) fuelled with small pieces of wood or paper
>briquette.
> Developed by New Dawn Engineering, South Africa.
>(d) Semi gasifier stove, fuelled with wood chips, earlier developed by
>Z-mart stove, USA and modified by Dian Desa, Indonesia.
>
>The February 2003 edition of GLOW magazine (Vol 29) features Improved
>Cookstoves, Indoor air pollution and health.
>
>Tom Miles
>
>

From crispin at NEWDAWN.SZ Sun May 18 01:39:51 2003
From: crispin at NEWDAWN.SZ (Newdawn (Africa Online))
Date: Tue Aug 10 18:30:23 2004
Subject: Re Using steam to move heat through a stove system.
Message-ID: <SUN.18.MAY.2003.073951.0200.CRISPIN@NEWDAWN.SZ>

Sorry for the delay - it bounced! - CPP

Dear Lanny

S-s-s-s-steam heat...

Well, I have thought for some time that there is a lot of heat transferred
to the pot using steam especially during the initial heating process - that
critical time when the fire isn't doing all that well, the stove body is not
up to temp and the wood is wet or damp.

My observations are that the steam is generated in the fire and from boiling
the water in the wood. This is transported to the pot where it condenses
liberating lots of heat, then the water droplets are (some of them) taken
away in the form of small droplets, rather than entirely as steam again
(which would not yield much net heat). Some droplets are pushed upwards on
the pot side and are taken away by the hot gases using what is, after
another few millimetres, wasted heat. There is a net gain of heat in that
process.

Also, the steam can condense in the airsteam past the cold pot and give up
heat to the surrounding gases (which pass it to the pot), form a water
droplet and then carry on upwards riding the gas current.

Both of these are in process all the time. The analysis of what heat
transfer is, as I read it, a bit theoretical and incomplete - rather like
discussion of the water cycle which is not as described in Grade 5 texbooks
but something quite complicated.

I have just been having a chat with Dean S off the group about the amount
water in wood for testing purposes. Removing all the water from wood before
testing interferes with the steam/condensation/droplet/riding-the-waves
scenario and 'unmoderates' the fire and therefore interferes with the stove
operation.

The steam. like salts in lowveldt hardwood that makes such wonderful
roasting coals, moderates the fire and produces a useful effect at the same
time: an open-ended heat pipe with steam as the working medium. As
simmering is only about a 95 deg process, steam condensation can drive the
process far better than 'theoretical' fires with no moisture in them.

It is correct to say that heat transfer from hot dry gases is best done with
certain (high) velocities at certain gaps yatta-yatta but in a real wood
fire there is a lot going on that helps heat transfer at low velocities.
The theory does not carry over from large 'pure' or 'ideal' systems to small
fires. One proof of this (to me) is the very high efficiencies I can get a
very low gas velocities where the conditions are created to give 'things' a
chance to work. One is the chance for steam condense and give up its heat
on the pot surface.

Regards
Crispin

----- Original Message -----
From: "Lanny Henson" <lanny@ROMAN.NET>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Friday, May 16, 2003 2:04 AM
Subject: [STOVES] Using steam to move heat through a stove system.

From tombreed at ATTBI.COM Sun May 18 01:17:25 2003
From: tombreed at ATTBI.COM (Tom Reed)
Date: Tue Aug 10 18:30:23 2004
Subject: Steam heat ... aaah
Message-ID: <SAT.17.MAY.2003.231725.0600.TOMBREED@ATTBI.COM>

Dear Crispin and All:

Steam heat can be incredibly effective - when no other gases are present and
the pot is cold, because the condensation of water delivers 550 cal/gm
rather than 0.5 cal/(degree of temperature difference).

However, this only happens when no other gases are present, because a
mixture of steam and air or other gases will condense steam momentarily, but
then a boundary layer of other gas prevents effective condensation. For
this reason they go to incredible lengths to get other gases out of the
steam for high heat transfer in boiler tubes etc.

So see if you see water condensing on the bottom of the cold pot as an
indication of very high heat transfer.

~~~~~~~
To a much lesser extent steam is better than most gases even when it doesn't
condense, because the molecular weight is 18 vs 28 for N2 or CO or 44 for
CO2, and the heat transfer is proportional to MW^1/2.

Thanks for your comments, hope these add..

Yours truly, TOM REED BEF STOVES
Dr. Thomas B. Reed
1810 Smith Rd., Golden, CO 80401
tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
----- Original Message -----
From: "Newdawn (Africa Online)" <crispin@NEWDAWN.SZ>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Saturday, May 17, 2003 11:39 PM
Subject: [STOVES] Re Using steam to move heat through a stove system.

> Sorry for the delay - it bounced! - CPP
>
> Dear Lanny
>
> S-s-s-s-steam heat...
>
> Well, I have thought for some time that there is a lot of heat transferred
> to the pot using steam especially during the initial heating process -
that
> critical time when the fire isn't doing all that well, the stove body is
not
> up to temp and the wood is wet or damp.
>
> My observations are that the steam is generated in the fire and from
boiling
> the water in the wood. This is transported to the pot where it condenses
> liberating lots of heat, then the water droplets are (some of them) taken
> away in the form of small droplets, rather than entirely as steam again
> (which would not yield much net heat). Some droplets are pushed upwards
on
> the pot side and are taken away by the hot gases using what is, after
> another few millimetres, wasted heat. There is a net gain of heat in that
> process.
>
> Also, the steam can condense in the airsteam past the cold pot and give up
> heat to the surrounding gases (which pass it to the pot), form a water
> droplet and then carry on upwards riding the gas current.
>
> Both of these are in process all the time. The analysis of what heat
> transfer is, as I read it, a bit theoretical and incomplete - rather like
> discussion of the water cycle which is not as described in Grade 5
texbooks
> but something quite complicated.
>
> I have just been having a chat with Dean S off the group about the amount
> water in wood for testing purposes. Removing all the water from wood
before
> testing interferes with the steam/condensation/droplet/riding-the-waves
> scenario and 'unmoderates' the fire and therefore interferes with the
stove
> operation.
>
> The steam. like salts in lowveldt hardwood that makes such wonderful
> roasting coals, moderates the fire and produces a useful effect at the
same
> time: an open-ended heat pipe with steam as the working medium. As
> simmering is only about a 95 deg process, steam condensation can drive the
> process far better than 'theoretical' fires with no moisture in them.
>
> It is correct to say that heat transfer from hot dry gases is best done
with
> certain (high) velocities at certain gaps yatta-yatta but in a real wood
> fire there is a lot going on that helps heat transfer at low velocities.
> The theory does not carry over from large 'pure' or 'ideal' systems to
small
> fires. One proof of this (to me) is the very high efficiencies I can get
a
> very low gas velocities where the conditions are created to give 'things'
a
> chance to work. One is the chance for steam condense and give up its heat
> on the pot surface.
>
> Regards
> Crispin
>
>
> ----- Original Message -----
> From: "Lanny Henson" <lanny@ROMAN.NET>
> To: <STOVES@LISTSERV.REPP.ORG>
> Sent: Friday, May 16, 2003 2:04 AM
> Subject: [STOVES] Using steam to move heat through a stove system.
>
>
> Stove Friends,
> I noticed Dr Karve uses stem to carry heat to the pots in his very
efficient
> charcoal stove.
> Could there be a use for steam heat in a biomass stoves? Maybe not in a
> single pot system but maybe in a stacked pot system? How about stacking
> insulated pot shields. Each shield would have two handles and hold a pot
in
> the best position for flow in a stack. With the handles you could easily
> change he order of the stack as necessary.
> Lanny Henson

From snkm at BTL.NET Sun May 18 11:23:23 2003
From: snkm at BTL.NET (Peter Singfield)
Date: Tue Aug 10 18:30:23 2004
Subject: Steam heat ... aaah -- pressure cooking!
Message-ID: <SUN.18.MAY.2003.092323.0600.SNKM@BTL.NET>

Dear All;

If everyone concerned with cooking with minimal fuel used pressure cookers
the end result would probably be a saving of 70% or over in fuel use -- no
matter what kind of stove was used.

Further -- industrial steam jacketed pots are the mainstay "cooker" in most
large institutional kitchens.

Steam and cooking have been around for a long time. And really -- for many
reasons -- direct flame cooking can never be as efficient -- in fuel use or
in nutritional content.

Over heating food when cooking is a terrible destroyer of nutritional
values. Steam cooking makes sure that can't happen.

You can cook in a pressure cooker faster than using a micro-wave -- another
"bonus".

My "costs" using a butane stove and a pressure cooker are probably less
than using fire wood and open flame cooking.

It takes very little heat to cook with a pressure cooker -- especially if
the pressure cooker has any insulation at all.

The idea is to maintain pressure -- not blow of excess heat as team.

If you were to use pressure cooking with biomass fuels -- you would need
two stoves.

One of larger capacity to bring pot to a boil and pressure -- then a very
tiny one to keep it there.

Peter Singfield

Belize

-- using a pressure cooker every day.

At 11:17 PM 5/17/2003 -0600, Tom Reed wrote:
>Dear Crispin and All:
>
>Steam heat can be incredibly effective - when no other gases are present and
>the pot is cold, because the condensation of water delivers 550 cal/gm
>rather than 0.5 cal/(degree of temperature difference).
>
>However, this only happens when no other gases are present, because a
>mixture of steam and air or other gases will condense steam momentarily, but
>then a boundary layer of other gas prevents effective condensation. For
>this reason they go to incredible lengths to get other gases out of the
>steam for high heat transfer in boiler tubes etc.
>
>So see if you see water condensing on the bottom of the cold pot as an
>indication of very high heat transfer.
>
>
>~~~~~~~
>To a much lesser extent steam is better than most gases even when it doesn't
>condense, because the molecular weight is 18 vs 28 for N2 or CO or 44 for
>CO2, and the heat transfer is proportional to MW^1/2.
>
>Thanks for your comments, hope these add..
>
>Yours truly, TOM REED BEF STOVES
>Dr. Thomas B. Reed
>1810 Smith Rd., Golden, CO 80401
>tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
>----- Original Message -----
>From: "Newdawn (Africa Online)" <crispin@NEWDAWN.SZ>
>To: <STOVES@LISTSERV.REPP.ORG>
>Sent: Saturday, May 17, 2003 11:39 PM
>Subject: [STOVES] Re Using steam to move heat through a stove system.
>
>
>> Sorry for the delay - it bounced! - CPP
>>
>> Dear Lanny
>>
>> S-s-s-s-steam heat...
>>
>> Well, I have thought for some time that there is a lot of heat transferred
>> to the pot using steam especially during the initial heating process -
>that
>> critical time when the fire isn't doing all that well, the stove body is
>not
>> up to temp and the wood is wet or damp.
>>
>> My observations are that the steam is generated in the fire and from
>boiling
>> the water in the wood. This is transported to the pot where it condenses
>> liberating lots of heat, then the water droplets are (some of them) taken
>> away in the form of small droplets, rather than entirely as steam again
>> (which would not yield much net heat). Some droplets are pushed upwards
>on
>> the pot side and are taken away by the hot gases using what is, after
>> another few millimetres, wasted heat. There is a net gain of heat in that
>> process.
>>
>> Also, the steam can condense in the airsteam past the cold pot and give up
>> heat to the surrounding gases (which pass it to the pot), form a water
>> droplet and then carry on upwards riding the gas current.
>>
>> Both of these are in process all the time. The analysis of what heat
>> transfer is, as I read it, a bit theoretical and incomplete - rather like
>> discussion of the water cycle which is not as described in Grade 5
>texbooks
>> but something quite complicated.
>>
>> I have just been having a chat with Dean S off the group about the amount
>> water in wood for testing purposes. Removing all the water from wood
>before
>> testing interferes with the steam/condensation/droplet/riding-the-waves
>> scenario and 'unmoderates' the fire and therefore interferes with the
>stove
>> operation.
>>
>> The steam. like salts in lowveldt hardwood that makes such wonderful
>> roasting coals, moderates the fire and produces a useful effect at the
>same
>> time: an open-ended heat pipe with steam as the working medium. As
>> simmering is only about a 95 deg process, steam condensation can drive the
>> process far better than 'theoretical' fires with no moisture in them.
>>
>> It is correct to say that heat transfer from hot dry gases is best done
>with
>> certain (high) velocities at certain gaps yatta-yatta but in a real wood
>> fire there is a lot going on that helps heat transfer at low velocities.
>> The theory does not carry over from large 'pure' or 'ideal' systems to
>small
>> fires. One proof of this (to me) is the very high efficiencies I can get
>a
>> very low gas velocities where the conditions are created to give 'things'
>a
>> chance to work. One is the chance for steam condense and give up its heat
>> on the pot surface.
>>
>> Regards
>> Crispin
>>
>>
>> ----- Original Message -----
>> From: "Lanny Henson" <lanny@ROMAN.NET>
>> To: <STOVES@LISTSERV.REPP.ORG>
>> Sent: Friday, May 16, 2003 2:04 AM
>> Subject: [STOVES] Using steam to move heat through a stove system.
>>
>>
>> Stove Friends,
>> I noticed Dr Karve uses stem to carry heat to the pots in his very
>efficient
>> charcoal stove.
>> Could there be a use for steam heat in a biomass stoves? Maybe not in a
>> single pot system but maybe in a stacked pot system? How about stacking
>> insulated pot shields. Each shield would have two handles and hold a pot
>in
>> the best position for flow in a stack. With the handles you could easily
>> change he order of the stack as necessary.
>> Lanny Henson
>

From crispin at NEWDAWN.SZ Sun May 18 12:43:07 2003
From: crispin at NEWDAWN.SZ (Newdawn (Africa Online))
Date: Tue Aug 10 18:30:23 2004
Subject: Steam heat ... aaah
Message-ID: <SUN.18.MAY.2003.184307.0200.CRISPIN@NEWDAWN.SZ>

Dear Tom

>Steam heat can be incredibly effective - when no other gases are
>present and the pot is cold, because the condensation of water
>delivers 550 cal/gm rather than 0.5 cal/(degree of temperature
>difference).

Suppose the steam 'molecules' were all separated from each other and you
drop the temperature. Does that give the steam equivalent of super-cooled
water, where it remains liquid at temperatures well below freezing?

In that case, the steam would give up only 'steam value' heat per gm.
But...

>However, this only happens when no other gases are present, because a
>mixture of steam and air or other gases will condense steam momentarily,
>but then a boundary layer of other gas prevents effective condensation.

Do you mean _further_ effective condensation? Some has already condensed,
right? What about the impracticality of there being an insulating layer
around each steam molecule? Surely the steam condenses in little droplet -
billions of them, releasing heat to the surrounding gases (by radiation and
tiny amounts of conduction) which in turn radiate heat to their surrounds,
including the pot.

It seems to me that some condensation can be going on in the gas layer(s)
against and near the pot if the temperature is low enough.

>So see if you see water condensing on the bottom of the cold pot as
>an indication of very high heat transfer.

I thought this was perhaps only going to happen, or most usually going to
happen, if there was a lot of water in the wood. I had avoided the subject
before because it is devilishly difficult to try to calculate the amount of
heat that would be gained from the type of condensation, but I remain
convinced that there is a certain amount of heat transferred from the
initial fire to the pot using the moisture in the wood as a transfer medium,
seen or unseen.

>To a much lesser extent steam is better than most gases even when it
>doesn't condense, because the molecular weight is 18 vs 28 for N2
>or CO or 44 for CO2, and the heat transfer is proportional to MW^1/2.

Agreed in principle, but I am not sure what your MW^1/2 means. Is that an
Imperial unit? Mass? Watts? Weight?

Thanks
Crispin

From tstubb at IHUG.CO.NZ Sun May 18 15:47:48 2003
From: tstubb at IHUG.CO.NZ (Thomas Stubbing)
Date: Tue Aug 10 18:30:23 2004
Subject: Steam heat ... aaah
Message-ID: <MON.19.MAY.2003.074748.1200.TSTUBB@IHUG.CO.NZ>

Dear Tom and All:

Tom Reed wrote:

> Dear Crispin and All:
>
> Steam heat can be incredibly effective - when no other gases are present and
> the pot is cold, because the condensation of water delivers 550 cal/gm
> rather than 0.5 cal/(degree of temperature difference).
>
> However, this only happens when no other gases are present, because a
> mixture of steam and air or other gases will condense steam momentarily, but
> then a boundary layer of other gas prevents effective condensation. For
> this reason they go to incredible lengths to get other gases out of the
> steam for high heat transfer in boiler tubes etc.
>
> So see if you see water condensing on the bottom of the cold pot as an
> indication of very high heat transfer.

Pure atmospheric pressure steam condenses at its 100 oC saturation or dew point
temperature and will eventually heat the contents of a pot it condenses on to
the same 100 oC. However, the saturation or dew point temperature a 50/50
steam/air mixture by volume is 83 oC, and that temperature falls as steam
condenses out of it and the proportion of air increases.

>
>
> ~~~~~~~
> To a much lesser extent steam is better than most gases even when it doesn't
> condense, because the molecular weight is 18 vs 28 for N2 or CO or 44 for
> CO2, and the heat transfer is proportional to MW^1/2.

When atmospheric pressure steam is heated to above 100 oC it becomes superheated
steam, which is what Tom is referring to, and that it also true of the steam
present in air and/or combustion gases when they are above the mixture's then
lower saturation temperature.

Dry air requires around 1 kJ/kg/oC to heat it (roughly the same applies to dry
combustion gases), while superheated steam requires around 2 kJ/kg/oC to heat
it, and the same kJ/kg/oC are released when the respective gases are cooled, for
example by passage around a cooler pot.

If there is moisture in the wood fuel, some of the dry wood's energy is used to
heat and evaporate that moisture, with most of that energy being used to
evaporate it.

The EVAPORATION energy becomes the steam's latent heat, which is only recovered
if and when the steam condenses, which is why burning moist wood is wasteful.

Theoretically, if wood has an an around 86% moisture content, then ALL of the
14% dry wood's combustion energy is needed to heat and evaporate the moisture,
leaving none for cooking!

Peter Singfield's comment about pressure cookers being more efficient is correct
because it takes much longer to cook food in 100 oC water than in the above 100
oC water in a pressure cooker.

Regards,

Thomas

>
>
> Thanks for your comments, hope these add..
>
> Yours truly, TOM REED BEF STOVES
> Dr. Thomas B. Reed
> 1810 Smith Rd., Golden, CO 80401
> tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
> ----- Original Message -----
> From: "Newdawn (Africa Online)" <crispin@NEWDAWN.SZ>
> To: <STOVES@LISTSERV.REPP.ORG>
> Sent: Saturday, May 17, 2003 11:39 PM
> Subject: [STOVES] Re Using steam to move heat through a stove system.
>
> > Sorry for the delay - it bounced! - CPP
> >
> > Dear Lanny
> >
> > S-s-s-s-steam heat...
> >
> > Well, I have thought for some time that there is a lot of heat transferred
> > to the pot using steam especially during the initial heating process -
> that
> > critical time when the fire isn't doing all that well, the stove body is
> not
> > up to temp and the wood is wet or damp.
> >
> > My observations are that the steam is generated in the fire and from
> boiling
> > the water in the wood. This is transported to the pot where it condenses
> > liberating lots of heat, then the water droplets are (some of them) taken
> > away in the form of small droplets, rather than entirely as steam again
> > (which would not yield much net heat). Some droplets are pushed upwards
> on
> > the pot side and are taken away by the hot gases using what is, after
> > another few millimetres, wasted heat. There is a net gain of heat in that
> > process.
> >
> > Also, the steam can condense in the airsteam past the cold pot and give up
> > heat to the surrounding gases (which pass it to the pot), form a water
> > droplet and then carry on upwards riding the gas current.
> >
> > Both of these are in process all the time. The analysis of what heat
> > transfer is, as I read it, a bit theoretical and incomplete - rather like
> > discussion of the water cycle which is not as described in Grade 5
> texbooks
> > but something quite complicated.
> >
> > I have just been having a chat with Dean S off the group about the amount
> > water in wood for testing purposes. Removing all the water from wood
> before
> > testing interferes with the steam/condensation/droplet/riding-the-waves
> > scenario and 'unmoderates' the fire and therefore interferes with the
> stove
> > operation.
> >
> > The steam. like salts in lowveldt hardwood that makes such wonderful
> > roasting coals, moderates the fire and produces a useful effect at the
> same
> > time: an open-ended heat pipe with steam as the working medium. As
> > simmering is only about a 95 deg process, steam condensation can drive the
> > process far better than 'theoretical' fires with no moisture in them.
> >
> > It is correct to say that heat transfer from hot dry gases is best done
> with
> > certain (high) velocities at certain gaps yatta-yatta but in a real wood
> > fire there is a lot going on that helps heat transfer at low velocities.
> > The theory does not carry over from large 'pure' or 'ideal' systems to
> small
> > fires. One proof of this (to me) is the very high efficiencies I can get
> a
> > very low gas velocities where the conditions are created to give 'things'
> a
> > chance to work. One is the chance for steam condense and give up its heat
> > on the pot surface.
> >
> > Regards
> > Crispin
> >
> >
> > ----- Original Message -----
> > From: "Lanny Henson" <lanny@ROMAN.NET>
> > To: <STOVES@LISTSERV.REPP.ORG>
> > Sent: Friday, May 16, 2003 2:04 AM
> > Subject: [STOVES] Using steam to move heat through a stove system.
> >
> >
> > Stove Friends,
> > I noticed Dr Karve uses stem to carry heat to the pots in his very
> efficient
> > charcoal stove.
> > Could there be a use for steam heat in a biomass stoves? Maybe not in a
> > single pot system but maybe in a stacked pot system? How about stacking
> > insulated pot shields. Each shield would have two handles and hold a pot
> in
> > the best position for flow in a stack. With the handles you could easily
> > change he order of the stack as necessary.
> > Lanny Henson

From crispin at NEWDAWN.SZ Sun May 18 15:55:58 2003
From: crispin at NEWDAWN.SZ (Newdawn (Africa Online))
Date: Tue Aug 10 18:30:23 2004
Subject: RE Steam heat ... aaah -- pressure cooking!
Message-ID: <SUN.18.MAY.2003.215558.0200.CRISPIN@NEWDAWN.SZ>

Dear Peter

Pressure cookers: now we are talking!

I wholeheartedly agree. The problem is that people literally cannot afford
a pressure cooker. They cost more than a Vesto or any other small stove.
They are just way too expensive. Then there is that pesky business of
people wanting to stir the food and look at it etc. That mainstay food
around here is 'pap' which is mealie (corn) porridge and the 'dry' version
has to be just ever so slightly burned when dry to get a particular toasted
flavour. I would guess that more than 3/4 of the fuel used in rural
southern Africa cooks this food, just over half of it the dry pap. Regional
flavours and preferences abound, but the point is that it won't work in a
pressure cooker.

Still, the principle applies. You can especially render tough meat into a
palatable state which is bound to save money.

About the two stoves you mentioned: I really think I have cracked that one.
Implement the principles. Our product seems to be able to maintain a heat
output in the low hundreds of watts (2-300) for a long time with a very high
pHU while still being able to produce 3-4 kw if you really want to. The key
to that is (to bleat again about it) pre-heating the primary air so the fire
doesn't go out. That plus a combination of fuel metering and air control
and in our case, gas insulation (air).

What about putting a preheated pressure cooker into a "heat bag" otherwise
known as a 'retained heat cooker'? Surely that would take care of the low
fire part?

We are promoting the use of a Vesto and heat bag together as a super-saver
of fuel. We are still working out how to get it to catch on though. It is
a really different approach. In places with very little fuel it might get
adopted fastest.

Thanks
Crispin

From snkm at BTL.NET Sun May 18 20:40:38 2003
From: snkm at BTL.NET (Peter Singfield)
Date: Tue Aug 10 18:30:23 2004
Subject: RE Steam heat ... aaah -- pressure cooking!
Message-ID: <SUN.18.MAY.2003.184038.0600.SNKM@BTL.NET>

Dear Crispin;

Your absolutely right with all your points. And you missed at least one
other -- blowing up pressure cookers!!

Even when they pop off steam it frightens the cooks here "badly".

>That mainstay food
>around here is 'pap' which is mealie (corn) porridge and the 'dry' version
>has to be just ever so slightly burned when dry to get a particular toasted
>flavour.

Here it is the corn tortilla -- very healthy food. Very energy inefficient
to make.

>What about putting a preheated pressure cooker into a "heat bag" otherwise
>known as a 'retained heat cooker'? Surely that would take care of the low
>fire part?

I believe a small stove should be designed that is a "no-pressure" steam
kettle.

That is a pot lines with a steam jacket -- with free venting of steam
around upper rim. No safety problems. But lower cooking temperature.

This pot fits perfectly on the stove in question -- and becomes an option.

Doubt would ever have single user effectiveness -- but should work well for
most eateries.

The pot could be lifted off and a plate substituted for tortilla -- etc.

Or a fry pan that just fits right??

I'm getting a small TIG welder in next week. Have acquired more equipments
from India -- a cane crusher included -- so have much vats and tanks to
build -- not to mention a basic distillery.

Plan to role my own.

You might be interested in the TIG welder -- it runs on 115 volts and draws
16 amps max. That means it will run off just about any small generator.
2000 watts is plenty.

http://www.usaweld.com/product_page/tig_welder/tig100.html

I'll be using 18 to 22 gauge sheet metal -- iron.

Probably build a steam kettle -- just to try the concept.

I also have to build a furnace or two -- probably up draft gasifiers --
with direct combustion over and above the "pit" grate.

Kind of a primary/secondary combustion in one pass -- like the Hurst Boiler
designs.

Basically a bottom feed up draft gasifier. I believe it was Tom that used a
cigarette standing on end to demonstrate that concept??

The reason being -- I am hoping -- is a more regulated combustion process.
That is better fuel/heat control.

I've picked up some experience running the coconut drying furnace -- you
can see that at:

http://turneffecoconut.com/

It is direct combustion with two burning levels (primary -- secondary air)
but often still runs to hot -- or to cold.

However -- if fiddled with -- a huge pile of charcoal can be created and
then slow burned at right heat intensity by closing bottom air almost
completely and adjusting over air accordingly.

I put a heavy wire screen mesh -- folded over four time -- over the
charcoal and gasses passing through then burn with secondary air.

The problem is maintaining the amount of charcoal -- as in adding more
coconut shell. This furnace is not designed right for that aspect -- is
clumsy. But I have observed enough to make a few modifications- - and
eventually evolve a better operating device.

Lime marl is so common here -- and I used a mixture -- eight parts marl --
one part cement -- as replacement for brick.

This was "cast" between a cement block outer "frame" and a piece of regular
corrugated sheet roofing metal -- but the new kind -- not galvanized -- I
believe an iron aluminum "creation"??

The flames/heat of the fire box strikes against this -- then the four inch
thick cast marl -- then the cement blocks.

The fire box is a 16 gauge iron sheet "box" -- 1 foot square by 8 inch high
-- that sits on a grate made of welded 1/2 steel cement rebar -- that sits
on 4 inch legs -- and fits in the furnace fire chamber. The fine ash falls
through this grate to the ash pan under This leaves about 4 inches of
air/space between fire pit and the above mentioned furnace walls.

There is a baffle plate of 1/8 iron plate over the fire pit with a two inch
space behind that and the flat plate above which the coconuts gratings sit
on. This space can be carbureted with fresh air to make sure the coconut
gratings are not over heated.

The fumes -- flue gasses -- flows between the top plate and a cast marl
"bed" -- length of 10 ft -- through a four inch space -- width of plate --
32 inches.

The chimney is 18 feet high and made from a salvaged -- bottom rotted out
-- large butane/propane tank cast into a cement pad with a rolled piece
(into an 8 inch tube -- then pop riveted) 14 foot length of that same
corrugated roofing material -- mounted from the top collar.

This is all working surprisingly well.

No budget is the true mother of innovation!!

Peter

At 09:55 PM 5/18/2003 +0200, Newdawn (Africa Online) wrote:
>Dear Peter
>
>Pressure cookers: now we are talking!
>
>I wholeheartedly agree. The problem is that people literally cannot afford
>a pressure cooker. They cost more than a Vesto or any other small stove.
>They are just way too expensive. Then there is that pesky business of
>people wanting to stir the food and look at it etc. That mainstay food
>around here is 'pap' which is mealie (corn) porridge and the 'dry' version
>has to be just ever so slightly burned when dry to get a particular toasted
>flavour. I would guess that more than 3/4 of the fuel used in rural
>southern Africa cooks this food, just over half of it the dry pap. Regional
>flavours and preferences abound, but the point is that it won't work in a
>pressure cooker.
>
>Still, the principle applies. You can especially render tough meat into a
>palatable state which is bound to save money.
>
>About the two stoves you mentioned: I really think I have cracked that one.
>Implement the principles. Our product seems to be able to maintain a heat
>output in the low hundreds of watts (2-300) for a long time with a very high
>pHU while still being able to produce 3-4 kw if you really want to. The key
>to that is (to bleat again about it) pre-heating the primary air so the fire
>doesn't go out. That plus a combination of fuel metering and air control
>and in our case, gas insulation (air).
>
>What about putting a preheated pressure cooker into a "heat bag" otherwise
>known as a 'retained heat cooker'? Surely that would take care of the low
>fire part?
>
>We are promoting the use of a Vesto and heat bag together as a super-saver
>of fuel. We are still working out how to get it to catch on though. It is
>a really different approach. In places with very little fuel it might get
>adopted fastest.
>
>Thanks
>Crispin
>

From adkarve at PN2.VSNL.NET.IN Sun May 18 23:58:32 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:23 2004
Subject: Steam heat ... aaah
Message-ID: <MON.19.MAY.2003.092832.0530.ADKARVE@PN2.VSNL.NET.IN>

Dear Stovers,
yes I do use steam in my cooker-and-stove system, but the steam does not
come from the fuel. My system consists of a non-pressurised closed vessel,
which contains about 150 ml of water. The cookpots are stacked inside this
vessel and the lid is closed. The lid allows steam to escape without blowing
itself off. The stove and the cooker are enclosed by a cylindrical metallic
sleeve, so that the cooker is heated not just from the bottom but from all
the sides. Just 100 g of charcoal is enough to cook a meal of rice, beans
and vegetables (or meat) for a family of 5. The coal is made from
agricultural waste biomass. In the case of most agricultural crops, we
harvest only about 30 to 40% as useful produce, and the rest, although it
has consumed water, fertilizers and pesticides, is just thrown away. A rural
family using our charcoaling process can earn a monthly income of Rs. 5000
(about US$ 100) which is more than the income of an industrial labourer
working in a city. 13 of our kilns are now continuously in operation. We
have so far sold about 500 of these cookers in the city of Pune and we sell
about 5 tonnes of char briquettes every month. The price of the cooker,
made completely of stainless steel, is Rs. 350 (about US$ 7) and the char
briquettes are sold for Rs. 7 per kg (about U.S.Cents 14). We have now made
a video CD showing the entire process of charcoaling, briquetting and
operating the stove-and-cooker system (commentary in English). The price of
the CD itself is negiligible (about US$ 2) but the postage cost is about US$
15 for locations outside India.
Dr.A.D.Karve, President,
Appropriate Rural Technology Institute
Pune, India.

From crispin at NEWDAWN.SZ Mon May 19 04:08:57 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:23 2004
Subject: RE Steam heat ... aaah -- your equipment
Message-ID: <MON.19.MAY.2003.100857.0200.CRISPIN@NEWDAWN.SZ>

Dear Peter

Nice to hear that you got some additional equipment. I find that a MIG
welder is about 3 times as fast as a stick welder so there is a real saving
in time if you 'have to do things yourself'. I bought a very second hand
Lincoln from a junk dealer in JHB with knobs that make no difference to the
welding at all. It has taps on the main coil so I can choose a current
level. We are running argon with a small amount of O2 in it. I can
recommend you use some O2 in you gas mix. It apparently sets fire to some
of the iron and welds with a lower current though I think it is weird to do
that but it works well.

Now don't melt with jealousy, but I was recently _given_ a working spot
welder. Man, I have wanted one of these for years! It is about 12,000
amps, maybe 20,000 output which draws 40 amps at 380VAC. It took me a month
to save enough to buy a cable to connect it. I already accidently erased
two pixels on my watch using it making some parts for the Vesto. Have to
keep things away from it. It apparently also erases credit cards with ease.
Oops.

So, now I can spotweld galv sheets together by melting the zinc. It works
quite well as a form of soldering. I took a sheet 0.5x85x875mm and made a
ring, then pressed it into a radiused groove in a plate and got a 'rolled
edge'. That means it looked like the top of a large very short paint can:
circular lip rolled outwards and around on itself, sitting atop a thin
cylinder. I am using it for the heat shields. No more hammering lips (my
aching wrist!). It looks so-o-o much better.

The 3CR12 spotwelds easily so bye-bye to purchasing stainless steel welding
rods. Faster and far cheaper. That applies to the fire grate and other SS
parts I have. I think we are approaching the 30 minute mark on making a
stove, start to finish.

You can weld surprisingly thin materials with you machine if you turn it
down and make very brief welds without moving the head. Let the wire, as
the power shuts off, touch only the molten glob that initially forms rather
than moving the head and welding new material. Point-hold-press-lift
finger-move head. We are able to consistently weld 1mm mild steel sheet
using a 1.2mm wire doing that.

I will give some thought to your adding-coconut fuel problem.

Stay well,
Crispin

From tombreed at ATTBI.COM Mon May 19 01:46:03 2003
From: tombreed at ATTBI.COM (Tom Reed)
Date: Tue Aug 10 18:30:23 2004
Subject: More on Welding
Message-ID: <SUN.18.MAY.2003.234603.0600.TOMBREED@ATTBI.COM>

Dear Crispin and All:

Glad to hear these practical discussions at stoves. Long ago I was the
director of welding research for the Linde Air company. For about a month
until I discovered that I was there only as a buffer between management and
researchers. Left the company after that.

I never heard of adding a little oxygen to argon. Hard to stuff other gases
into those high pressure tanks!

~~~~~~~
We have been manufacturing our WoodGas Campstove in a small garage shop. We
try to keep with simple tools that could be used anywhere in the world.

I bought a spotwelder from harbor freight last year for about $150, now $199
at http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=45689
[Made in Armenia of all things!]

It was the love of my life when I produced 15 beta test stoves last summer.
However, it won't weld aluminum. Any suggestions?

I have just bought their MIG welder at
http://www.harborfreight.com/cpi/ctaf/headsearch.taf?function=Search
for $199. It's small and compact and uses flux coated wire, no gas bottle
needed with mild steel. Welds a nice bead on 1/8 in steel.

Also bought their 30in shear/brake/roll for $150. Seems to have gone up to
$300 at
http://www.harborfreight.com/cpi/ctaf/headsearch.taf?function=Search

These three tools make almost anything possible in sheet metal.

Onward,

TOM REED

Dr. Thomas B. Reed
1810 Smith Rd., Golden, CO 80401
tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
----- Original Message -----
From: "Crispin" <crispin@newdawn.sz>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Monday, May 19, 2003 2:08 AM
Subject: [STOVES] RE Steam heat ... aaah -- your equipment

> Dear Peter
>
> Nice to hear that you got some additional equipment. I find that a MIG
> welder is about 3 times as fast as a stick welder so there is a real
saving
> in time if you 'have to do things yourself'. I bought a very second hand
> Lincoln from a junk dealer in JHB with knobs that make no difference to
the
> welding at all. It has taps on the main coil so I can choose a current
> level. We are running argon with a small amount of O2 in it. I can
> recommend you use some O2 in you gas mix. It apparently sets fire to some
> of the iron and welds with a lower current though I think it is weird to
do
> that but it works well.
>
> Now don't melt with jealousy, but I was recently _given_ a working spot
> welder. Man, I have wanted one of these for years! It is about 12,000
> amps, maybe 20,000 output which draws 40 amps at 380VAC. It took me a
month
> to save enough to buy a cable to connect it. I already accidently erased
> two pixels on my watch using it making some parts for the Vesto. Have to
> keep things away from it. It apparently also erases credit cards with
ease.
> Oops.
>
> So, now I can spotweld galv sheets together by melting the zinc. It works
> quite well as a form of soldering. I took a sheet 0.5x85x875mm and made a
> ring, then pressed it into a radiused groove in a plate and got a 'rolled
> edge'. That means it looked like the top of a large very short paint can:
> circular lip rolled outwards and around on itself, sitting atop a thin
> cylinder. I am using it for the heat shields. No more hammering lips (my
> aching wrist!). It looks so-o-o much better.
>
> The 3CR12 spotwelds easily so bye-bye to purchasing stainless steel
welding
> rods. Faster and far cheaper. That applies to the fire grate and other
SS
> parts I have. I think we are approaching the 30 minute mark on making a
> stove, start to finish.
>
> You can weld surprisingly thin materials with you machine if you turn it
> down and make very brief welds without moving the head. Let the wire, as
> the power shuts off, touch only the molten glob that initially forms
rather
> than moving the head and welding new material. Point-hold-press-lift
> finger-move head. We are able to consistently weld 1mm mild steel sheet
> using a 1.2mm wire doing that.
>
> I will give some thought to your adding-coconut fuel problem.
>
> Stay well,
> Crispin
>

From tombreed at ATTBI.COM Mon May 19 02:03:33 2003
From: tombreed at ATTBI.COM (Tom Reed)
Date: Tue Aug 10 18:30:23 2004
Subject: Cooking with Steam - and volatiles
Message-ID: <MON.19.MAY.2003.000333.0600.TOMBREED@ATTBI.COM>

Dear Karve and all:

I commented yesterday on the very high heat transfer from steam when all air
is removed. The steam cooker described below allows the initial generation
of steam to force all air out of the system and then heat by steam
condensation on the sides of each vessel. Very elegant, fast and efficient!
Much higher heat transfer than dilute steam on the bottom of a pot discussed
yesterday.

~~~~~
100 g of Karve's charcoal does more cooking than 1 kg of barbecue charcoal.
Still, the making of the charcoal is an inefficient step - UNLESS YOU USE
THE VOLATILES FOR COOKING AS WELL.

The inverted downdraft (charcoal making; top lit) gasifier cookstoves are
surprisingly efficient at making 20-25% charcoal and cooking a meal as well.
We are now working on a small charcoal fired mantle lamp to complete the
domestic equipment for a biomass fueled household.

~~~~~~~~~~~~
Barbecue charcoal cooking in the US has got to be the least efficient
cooking method in the Human arsenal. When you make the charcoal you lose
70% of the initial wood energy in the volatiles that come off. Then you
spread the charcoal out on a tray, it takes 10 minutes to light, you cook
for 20 minutes, probably with half the heat coming from the burning fat,
then when you are done the charcoal burns for another 12 hours. Must be
less than 1% efficient.

It is surprising that it is so popular with people who usually have
excellent gas or electric ovens 20 meters away in the kitchen (with a hood).
I suppose (a) it gets the man involved in cooking and makes him feel macho,
and (b) it gives a very even heat over a very large area.

~~~~~~~~~~~
Nice to have this forum for science, engineering and speculation that will
improve cooking for half the world.

TOM REED BEF STOVE ETC WORKS

Dr. Thomas B. Reed
1810 Smith Rd., Golden, CO 80401
tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
----- Original Message -----
From: "A.D. Karve" <adkarve@PN2.VSNL.NET.IN>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Sunday, May 18, 2003 9:58 PM
Subject: Re: [STOVES] Steam heat ... aaah

> Dear Stovers,
> yes I do use steam in my cooker-and-stove system, but the steam does not
> come from the fuel. My system consists of a non-pressurised closed
vessel,
> which contains about 150 ml of water. The cookpots are stacked inside
this
> vessel and the lid is closed. The lid allows steam to escape without
blowing
> itself off. The stove and the cooker are enclosed by a cylindrical
metallic
> sleeve, so that the cooker is heated not just from the bottom but from all
> the sides. Just 100 g of charcoal is enough to cook a meal of rice, beans
> and vegetables (or meat) for a family of 5. The coal is made from
> agricultural waste biomass. In the case of most agricultural crops, we
> harvest only about 30 to 40% as useful produce, and the rest, although it
> has consumed water, fertilizers and pesticides, is just thrown away. A
rural
> family using our charcoaling process can earn a monthly income of Rs. 5000
> (about US$ 100) which is more than the income of an industrial labourer
> working in a city. 13 of our kilns are now continuously in operation. We
> have so far sold about 500 of these cookers in the city of Pune and we
sell
> about 5 tonnes of char briquettes every month. The price of the cooker,
> made completely of stainless steel, is Rs. 350 (about US$ 7) and the char
> briquettes are sold for Rs. 7 per kg (about U.S.Cents 14). We have now
made
> a video CD showing the entire process of charcoaling, briquetting and
> operating the stove-and-cooker system (commentary in English). The price
of
> the CD itself is negiligible (about US$ 2) but the postage cost is about
US$
> 15 for locations outside India.
> Dr.A.D.Karve, President,
> Appropriate Rural Technology Institute
> Pune, India.
>

From tstubb at IHUG.CO.NZ Mon May 19 16:00:54 2003
From: tstubb at IHUG.CO.NZ (Thomas Stubbing)
Date: Tue Aug 10 18:30:23 2004
Subject: Steam heat ... aaah, PLUS WHY WE DO WHAT WE'RE DOING
Message-ID: <TUE.20.MAY.2003.080054.1200.TSTUBB@IHUG.CO.NZ>

Dear Tom and All:

Tom Reed wrote:

> Thomas:
>
> Good to have quantitative numbers added to the discussion. Isn't it
> surprising that we are still discovering and applying science to the oldest
> of world's technologies?
>

If making charcoal from wood and cooking with either is the oldest of the
world's technologies, then no, it's not surprising when you consider that there
are now far more people dependant on far less wood!

Our underlying mission, whether we are involved in sustainable forestry, in
efficient fuelwood and charcoal production, or in designing and distributing
efficient stoves, is to help ensure humanity's survival when fossil fuels run
out.

Thanks for asking the question!

Regards,

Thomas

From rdboyt at YAHOO.COM Thu May 22 08:17:55 2003
From: rdboyt at YAHOO.COM (Richard Boyt)
Date: Tue Aug 10 18:30:23 2004
Subject: Why I do what I do
Message-ID: <THU.22.MAY.2003.051755.0700.RDBOYT@YAHOO.COM>

Dear Thomas Stubbing and Stovers,

The question "why do I do what I'm doing" is troubling
because for me, at least, it is also an accusation.

Is it not remarkable arrogance for some smart-ass
local yokel from back woods Podunk Center to believe
that he knows more than millions of people who live
half way around the world on how to build their fires,
or make their stoves, or cook their food? Is it not
true that these millions have successfully survived
for millenia by observing the traditions passed down
to them by a thousand generations of ancestors?

And so I search for some justification for my belief
that I can help them. As problems change, so must
solutions. World resources that used to fill the
needs of five million people cannot sustainably fill
the needs of five billion plus- and growing
exponentially. Our present dependence on fossil fuels
for energy is clearly not sustainable. I too, am
greatly interested in searching for solutions to
problems in the areas of "... sustainable forestry,
... efficient fuel wood and charcoal production, ...
and designing and distributing efficient stoves." I
believe that these are essential, not only for the
welfare of humankind, but also for the welfare of
other living creatures, and even non-living entities,
such as the air, the waters, the soils, the rocks and
mountains, even the earth itself.

This forum may be an example of the phenomenon that
"the whole sometimes is greater than the sum of its
parts." Knowing that I am not alone encourages me to
keep trying. I know that I cannot make much of a
difference but perhaps between all of us, we can leave
a mark on that which is yet to be.

Dick Boyt
rdboyt@yahoo.com
20479 Panda Rd
Neosho, MO 64850

__________________________________
Do you Yahoo!?
The New Yahoo! Search - Faster. Easier. Bingo.
http://search.yahoo.com

From dstill at EPUD.NET Thu May 22 20:00:18 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:23 2004
Subject: Why I do what I do
Message-ID: <THU.22.MAY.2003.170018.0700.DSTILL@EPUD.NET>

Dear Thomas and Richard,

Why a person does what they do. In the little Mexican village where I lived
for ten years I think that the answer would be "Because of who you are".

Do humans get to direct their activity or are we born with distinct
personalities that control interests?

Is the ego able to say what the person does or does the unconscious push us
around?

Is there a God and Devil? Or are the skies clear for untroubled sailing?

Bringing beliefs to other cultures is historically suspect. Finding out how
nature works is not. I believe that finding out how nature works, exploring
thermodynamics in my case, is delightfully free of conundrums. No matter how
you answer the questions above, why to do the work is obvious. Dick Boyt and
so many folks on this list are my heroes as are others who work to discover
ways to live in partnership with our organic spaceship.

I would add that I think it's very important to document what is discovered!
Without good descriptions those who may want to use the knowledge will be
unable to do so.

Best,

Dean

From elk at WANANCHI.COM Sun May 18 04:01:29 2003
From: elk at WANANCHI.COM (elk)
Date: Tue Aug 10 18:30:23 2004
Subject: Keep on doing it!
Message-ID: <SUN.18.MAY.2003.110129.0300.ELK@WANANCHI.COM>

In the past millennia our ancestors rarely had problems finding a couple sticks of wood to cook their food on. And they rarely had to boil their drinking water in order to kill deadly pathogens. The majority of humans alive at this time now have to deal with fuel shortage on a daily basis.

We've got a new set of problems- and fresh challenges to survival appear daily.

Utilising waste is my particular fascination- & I know I've asked this question in the past, but I ask again:

Is it possible to make a stove that can cleanly burn chunks of rubber- of discarded automobile tires? I'd like to start working on this, but really don't have much of an idea where! Maybe a chimney is required? Possibly a small fan?

Ideas? Every urban centre in the world has this un-(or under) utilised resource. As I understand it, rubber has a terrifically high calorific content & given the right stove, could theoretically be a good fuel.

And another question- can rubber be carbonised to a charcoal fuel?

elk

----------------------------------------------
Elsen L.Karstad, Nairobi Kenya
elk@wananchi.com
http://www.chardust.com/

From dstill at EPUD.NET Thu May 22 22:30:17 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:23 2004
Subject: burning tires
Message-ID: <THU.22.MAY.2003.193017.0700.DSTILL@EPUD.NET>

Dear Elsen,

Yes, Larry Winiarski built a huge factory type burner of cut up tires that
burned white hot, nothing seen out of the stack. Turned a big generator on a
railroad car... Trick is to cut up the tires. You could contact him for
details.

Best,

Dean

-----Original Message-----
From: elk <elk@WANANCHI.COM>
To: STOVES@LISTSERV.REPP.ORG <STOVES@LISTSERV.REPP.ORG>
Date: Thursday, May 22, 2003 9:56 AM
Subject: [STOVES] Keep on doing it!

In the past millennia our ancestors rarely had problems finding a couple
sticks of wood to cook their food on. And they rarely had to boil their
drinking water in order to kill deadly pathogens. The majority of humans
alive at this time now have to deal with fuel shortage on a daily basis.

We've got a new set of problems- and fresh challenges to survival appear
daily.

Utilising waste is my particular fascination- & I know I've asked this
question in the past, but I ask again:

Is it possible to make a stove that can cleanly burn chunks of rubber- of
discarded automobile tires? I'd like to start working on this, but really
don't have much of an idea where! Maybe a chimney is required? Possibly a
small fan?

Ideas? Every urban centre in the world has this un-(or under) utilised
resource. As I understand it, rubber has a terrifically high calorific
content & given the right stove, could theoretically be a good fuel.

And another question- can rubber be carbonised to a charcoal fuel?

elk

----------------------------------------------
Elsen L.Karstad, Nairobi Kenya
elk@wananchi.com
http://www.chardust.com/

From andrew.heggie at DTN.NTL.COM Thu May 22 15:48:06 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:23 2004
Subject: Keep on doing it!
In-Reply-To: <003501c31d13$b140bd60$3841083e@pentium333>
Message-ID: <THU.22.MAY.2003.204806.0100.>

On Sun, 18 May 2003 11:01:29 +0300, elk wrote:

>
>Is it possible to make a stove that can cleanly burn chunks of rubber- of discarded automobile tires? I'd like to start working on this, but really don't have much of an idea where! Maybe a chimney is required? Possibly a small fan?

I am not completely sure what is in a tyre. The rubber chunks are
natural rubber (polyphenols??)and carbon black ( I used to drive past
a plant that made carbon black from air starved combustion of
petroleum, the flare stack was a beautiful purple blue flame
characteristic of CO, only fully appreciated at dusk), but what else?
Friends of the earth re[port higher levels of lead and chromium as
well as Polycyclic aromatic compounds and dioxins from cement works
burning tyres. The PAHs are likely to be from the incomplete
combustion of compounds containing benzine rings, the dioxins from
incomplete combustion of halogenated hydrocarbons. Then there is the
reinforcing plies and the steel bead. The steel is galvanised and this
could give problems were it burnt as the zinc oxide is volatile and
bad for you. I have burnt tyre chunks on the small scale but I did use
a fan, the results were smoke free but I did not do other tests.

A german paper available at
http://www.buethe.onlinehome.de/research.htm

concludes:
"Rubber materials are easy ignitable
and nearly inextinguishable
The composition of combustion effluents of rubber is strongly
dependent on the burned material and the fire conditions
(mainly temperature)
Effluents of an uncontrolled rubber fire are acute toxic
Chlorine and nitrogen containg materials possess an additional
toxicity
The lowest toxicity and the least problematic residues are produced
at the fire stage of a relatively high ventilated fully developed
fire"
>
>Ideas? Every urban centre in the world has this un-(or under) utilised resource. As I understand it, rubber has a terrifically high calorific content & given the right stove, could theoretically be a good fuel.

The thing is that the pyrolysis products need much more secondary air
than a wood fire and the PICs form sooty particles which are difficult
to burn if they become quenched. As rubber is likely to bee a
>
>And another question- can rubber be carbonised to a charcoal fuel?

I am fairly certain Alex English posted that he had carbonised tyre
chunks in his idd turbo burner a couple of years back.

Once the planes start flying again what chance of sending me a sample
of your new pillow briquettes?

From andrew.heggie at DTN.NTL.COM Thu May 22 16:35:05 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:23 2004
Subject: Keep on doing it!
In-Reply-To: <003501c31d13$b140bd60$3841083e@pentium333>
Message-ID: <THU.22.MAY.2003.213505.0100.>

I am sorry but I posted my previous message prematurely, unfortunately
I no longer see my own replies to list, which previously was a useful
sign of a successfully distributed message, though I do see the
acknowledgement from the list server.

Anyway, I had meant to add to be wary of products of combustion of
some synthetic rubbers, principally brake fluid seals I think. These
contain fluorocarbons which can produce hydrofluoric acid as a
breakdown product. This is an extremely nasty chemical as it reacts
with bone as a catalyst, the bone breaks down and the chemical "eats"
its way along without being deactivated. It also passes through skin
with no obvious injury. The only cure is to amputate at a sound piece
of bone.

AJH

From tstubb at IHUG.CO.NZ Thu May 22 17:44:24 2003
From: tstubb at IHUG.CO.NZ (Thomas Stubbing)
Date: Tue Aug 10 18:30:23 2004
Subject: Why I do what I do - See also Dean Still's and
Message-ID: <FRI.23.MAY.2003.094424.1200.TSTUBB@IHUG.CO.NZ>

Dear Richard et al,

We "smart-ass local yokel(s) from back woods Podunk Center" who are
members of this forum recognise the truth of Harry Truman's dictum that
"It's what you learn after you know it all that counts" and are seeking
to use the new knowledge we are together acquiring to help find
"solutions to problems in the areas of "... sustainable forestry, ...
efficient fuel wood and charcoal production, ... and designing and
distributing efficient stoves.".

We too "believe that these are essential, not only for the welfare of
humankind, but also for the welfare of other living creatures, and even
non-living entities, such as the air, the waters, the soils, the rocks
and mountains, even the earth itself.".

Dean Still and Elk added respectively:

I would add that I think it's very important to document what
is discovered!
Without good descriptions those who may want to use the
knowledge will be
unable to do so.

and:

In the past millennia our ancestors rarely had problems
finding a couple sticks of wood to cook their food on. And
they
rarely had to boil their drinking water in order to kill
deadly pathogens. The majority of humans alive at this time
now
have to deal with fuel shortage on a daily basis.

Taken together, that's why we do what we do!

Regards,

Thomas

Richard Boyt wrote:

> Dear Thomas Stubbing and Stovers,
>
> The question "why do I do what I'm doing" is troubling
> because for me, at least, it is also an accusation.
>
> Is it not remarkable arrogance for some smart-ass
> local yokel from back woods Podunk Center to believe
> that he knows more than millions of people who live
> half way around the world on how to build their fires,
> or make their stoves, or cook their food? Is it not
> true that these millions have successfully survived
> for millenia by observing the traditions passed down
> to them by a thousand generations of ancestors?
>
> And so I search for some justification for my belief
> that I can help them. As problems change, so must
> solutions. World resources that used to fill the
> needs of five million people cannot sustainably fill
> the needs of five billion plus- and growing
> exponentially. Our present dependence on fossil fuels
> for energy is clearly not sustainable. I too, am
> greatly interested in searching for solutions to
> problems in the areas of "... sustainable forestry,
> ... efficient fuel wood and charcoal production, ...
> and designing and distributing efficient stoves." I
> believe that these are essential, not only for the
> welfare of humankind, but also for the welfare of
> other living creatures, and even non-living entities,
> such as the air, the waters, the soils, the rocks and
> mountains, even the earth itself.
>
> This forum may be an example of the phenomenon that
> "the whole sometimes is greater than the sum of its
> parts." Knowing that I am not alone encourages me to
> keep trying. I know that I cannot make much of a
> difference but perhaps between all of us, we can leave
> a mark on that which is yet to be.
>
> Dick Boyt
> rdboyt@yahoo.com
> 20479 Panda Rd
> Neosho, MO 64850
>
> __________________________________
> Do you Yahoo!?
> The New Yahoo! Search - Faster. Easier. Bingo.
> http://search.yahoo.com

From tstubb at IHUG.CO.NZ Thu May 22 17:45:01 2003
From: tstubb at IHUG.CO.NZ (Thomas Stubbing)
Date: Tue Aug 10 18:30:23 2004
Subject: Keep on doing it!
Message-ID: <FRI.23.MAY.2003.094501.1200.TSTUBB@IHUG.CO.NZ>

Dear Elk,

elk wrote (snip):

> Utilising waste is my particular fascination- & I know I've asked this question in the past, but I ask again:
>
> Is it possible to make a stove that can cleanly burn chunks of rubber- of discarded automobile tires? I'd like to start working on this, but really don't have much of an idea where! Maybe a chimney is required? Possibly a small fan?
>
> Ideas? Every urban centre in the world has this un-(or under) utilised resource. As I understand it, rubber has a terrifically high calorific content & given the right stove, could theoretically be a good fuel.

You're right, it does have a high combustion energy content but when burnt produces highly polluting, filthy black smoke so its not safe to do so 'domestically'.

> And another question- can rubber be carbonised to a charcoal fuel?

Yes, and when the rubber is in used tyres the outputs are vapourised heating oil containing around 80% of the combustion energy and separately recoverable steel wire and carbon black.

The vapourised oil can be burnt immediately and, with the right equipment, cleanly to generate electricity and/or heat, or condensed as a light heating oil for later use.

Without the rubber stuck to it, the steel is saleable as scrap, and the carbon black, which can be shaken out of the steel, can be used as a filler in plastics or in unsophisticated rubber products such as mud-flaps, mats, etc., or briquetted and used as a fuel.

The process needs to be tightly controlled to prevent smoke pollution and to be viable needs to be done on a significant scale, preferably continuously.

My colleagues and I have a patent application pending and are working to design and sell equipment which will enable the growing menace of used tyre dumps advantageously to be eliminated.

Since writing the above I have seen and you will have received Dean's and Andrew's further contributions on this.

Regards,

Thomas

>
>
> elk
>
> ----------------------------------------------
> Elsen L.Karstad, Nairobi Kenya
> elk@wananchi.com
> http://www.chardust.com/

From nariphaltan at SANCHARNET.IN Fri May 23 01:06:25 2003
From: nariphaltan at SANCHARNET.IN (nariphaltan)
Date: Tue Aug 10 18:30:23 2004
Subject: Why I do what I do
Message-ID: <FRI.23.MAY.2003.103625.0530.>

I hope all of you may be able to find some answers at the following site;
http://education.vsnl.com/nimbkar/spiritual.html

Cheers.

Anil K. Rajvanshi
Director
Nimbkar Agricultural Research Institute
P.O.Box 44, Phaltan-415523
Maharashtra, India
Ph: 91-2166-222396/220945
Fax: 91-2166-221328
E-mail: nariphaltan@sancharnet.in

http://nariphaltan.virtualave.net
http://www.nariphaltan.org

----- Original Message -----
From: "Dean Still" <dstill@epud.net>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Friday, May 23, 2003 5:30 AM
Subject: Re: [STOVES] Why I do what I do

> Dear Thomas and Richard,
>
> Why a person does what they do. In the little Mexican village where I
lived
> for ten years I think that the answer would be "Because of who you are".
>
> Do humans get to direct their activity or are we born with distinct
> personalities that control interests?
>
> Is the ego able to say what the person does or does the unconscious push
us
> around?
>
> Is there a God and Devil? Or are the skies clear for untroubled sailing?
>
> Bringing beliefs to other cultures is historically suspect. Finding out
how
> nature works is not. I believe that finding out how nature works,
exploring
> thermodynamics in my case, is delightfully free of conundrums. No matter
how
> you answer the questions above, why to do the work is obvious. Dick Boyt
and
> so many folks on this list are my heroes as are others who work to
discover
> ways to live in partnership with our organic spaceship.
>
> I would add that I think it's very important to document what is
discovered!
> Without good descriptions those who may want to use the knowledge will be
> unable to do so.
>
> Best,
>
> Dean
>
>

From elk at WANANCHI.COM Fri May 23 01:12:55 2003
From: elk at WANANCHI.COM (elk)
Date: Tue Aug 10 18:30:23 2004
Subject: Burning rubber
Message-ID: <FRI.23.MAY.2003.081255.0300.ELK@WANANCHI.COM>

Aha! Lets collate:

Strips or chunks of rubber tire can be burnt in a small stove- with a fan
and preferably with a chimney. Probably using a ceramic liner to ensure high
heat in the combustion chamber.

Maybe a tube or two through the ceramic liner can be used to feed long
strips of rubber into the 'sweet spot' of the combustion chamber........ I'm
beginning to form a picture of what we need. Sunken pot to maximise heat
transfer, control air/fuel mixture and provide a seal to direct gasses out
the chimney. Stainless steel may have to be used in some places to resist
oxidation from high temperatures. A small sunken combustion chamber below
the pot- maybe half or less of the dia. of the pot. The pot's capacity could
be 20 litres? That would be a suitable size for the small school/restaurant
here in Kenya.

I am not under the delusion that this type stove can simply be handed over
to a family in a thatched hut as a replacement for their three stone hearth
or ceramic charcoal-burning jiko, but there is a huge demand for small
institutional stoves- small restaurants and tea kiosks abound here in
Africa, and fuel availability and cost rivals labour as the number two
cost-of-sale after actual food expense. Prove that a savings can be had &
the market for a rubber burning stove is yours! Anybody's.

Clean burning........ it's possible, eh? Does that necessarily imply
reduced harmful emissions? I know it does when smoke is flared during
charcoal production. What are the chances of other more toxic materials
finding their way into such a stove? Your description of the action of
hydrofluoric acid on mammalian bone is nightmarish Andrew!

This list started work on a 'World Stove' some years ago and gave up the
project in the face of a wide demographic range of uses and expectations-
mainly based on food types. Maybe a more specialised stove like this could
be a better focus of our attentions. A working stove 'out there', broad
dissemination of it's plans on the 'net' and a publication or two in widely
read journals/magazines might even galvanise other internet groups to follow
our lead to produce practical products- and forget about patents, profits
and other proprietary rights for a while.

Be brutal! Am I dreaming? Could we do this? Is rubber a suitable alternative
fuel for our attention?

As for samples of my soon-to-be-produced pillow-shaped VWB briquettes: I'm
happy to send out samples, particularly if assessments can be made. We are
looking for some lab assays on calorific content in particular. Problem is-
by IATA law, charcoal is a hazardous material and it's illegal to ship by
air. I'll have to check into how it'd have to be packaged if sent as HAZMAT
(hazardous material).

--------------------------
Elsen L. Karstad
elk@wananchi.com
www.chardust.com
Nairobi Kenya

From tombreed at ATTBI.COM Fri May 23 00:50:56 2003
From: tombreed at ATTBI.COM (Tom Reed)
Date: Tue Aug 10 18:30:23 2004
Subject: burning tires
Message-ID: <THU.22.MAY.2003.225056.0600.TOMBREED@ATTBI.COM>

Dear Dean and All:

We are all, perforce, mechanical engineers of sorts, but I hope we add some
combustion knowledge.

A correct air/fuel mixture is necessary for clean combustion. 30 years ago
there were lots of excuses for dirty combustion, large and small. With the
advent of the oxygen sensor (lambda meter, zirconia thimble, Bosch) it is
now possible to react instantaneously to changes in fuel level and keep
combustion clean as a large scale.

We haven't put one on our small stoves - yet.

Yours truly, TOM REED
WoodGas Stoveworks

Dr. Thomas B. Reed
1810 Smith Rd., Golden, CO 80401
tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
----- Original Message -----
From: "Dean Still" <dstill@epud.net>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Thursday, May 22, 2003 8:30 PM
Subject: Re: [STOVES] burning tires

> Dear Elsen,
>
> Yes, Larry Winiarski built a huge factory type burner of cut up tires that
> burned white hot, nothing seen out of the stack. Turned a big generator on
a
> railroad car... Trick is to cut up the tires. You could contact him for
> details.
>
> Best,
>
> Dean
>
>
> -----Original Message-----
> From: elk <elk@WANANCHI.COM>
> To: STOVES@LISTSERV.REPP.ORG <STOVES@LISTSERV.REPP.ORG>
> Date: Thursday, May 22, 2003 9:56 AM
> Subject: [STOVES] Keep on doing it!
>
>
> In the past millennia our ancestors rarely had problems finding a couple
> sticks of wood to cook their food on. And they rarely had to boil their
> drinking water in order to kill deadly pathogens. The majority of humans
> alive at this time now have to deal with fuel shortage on a daily basis.
>
> We've got a new set of problems- and fresh challenges to survival appear
> daily.
>
> Utilising waste is my particular fascination- & I know I've asked this
> question in the past, but I ask again:
>
> Is it possible to make a stove that can cleanly burn chunks of rubber- of
> discarded automobile tires? I'd like to start working on this, but really
> don't have much of an idea where! Maybe a chimney is required? Possibly a
> small fan?
>
> Ideas? Every urban centre in the world has this un-(or under) utilised
> resource. As I understand it, rubber has a terrifically high calorific
> content & given the right stove, could theoretically be a good fuel.
>
> And another question- can rubber be carbonised to a charcoal fuel?
>
> elk
>
>
> ----------------------------------------------
> Elsen L.Karstad, Nairobi Kenya
> elk@wananchi.com
> http://www.chardust.com/
>

From tombreed at ATTBI.COM Fri May 23 01:32:52 2003
From: tombreed at ATTBI.COM (Tom Reed)
Date: Tue Aug 10 18:30:23 2004
Subject: Why I do what I do
Message-ID: <THU.22.MAY.2003.233252.0600.TOMBREED@ATTBI.COM>

Dear Thomas, Dick and All:

The billions of people cooking primitively with wood for thousands of years
had no choice (and plenty of wood). Half the world has now moved on to a
point where we know a great deal more about combustion. So, in an effort to
improve the lot of the others we are all applying our knowledge to making
better stoves. Nothing arrogant about that.

Personally, I consider myself an innovative (not band aid) inventor in the
field of thermal processes, and as such consider it my duty and pleasure to
help.

Onward, TOM REED

Dr. Thomas B. Reed
1810 Smith Rd., Golden, CO 80401
tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
----- Original Message -----
From: "Richard Boyt" <rdboyt@YAHOO.COM>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Thursday, May 22, 2003 6:17 AM
Subject: [STOVES] Why I do what I do

> Dear Thomas Stubbing and Stovers,
>
> The question "why do I do what I'm doing" is troubling
> because for me, at least, it is also an accusation.
>
> Is it not remarkable arrogance for some smart-ass
> local yokel from back woods Podunk Center to believe
> that he knows more than millions of people who live
> half way around the world on how to build their fires,
> or make their stoves, or cook their food? Is it not
> true that these millions have successfully survived
> for millenia by observing the traditions passed down
> to them by a thousand generations of ancestors?
>
> And so I search for some justification for my belief
> that I can help them. As problems change, so must
> solutions. World resources that used to fill the
> needs of five million people cannot sustainably fill
> the needs of five billion plus- and growing
> exponentially. Our present dependence on fossil fuels
> for energy is clearly not sustainable. I too, am
> greatly interested in searching for solutions to
> problems in the areas of "... sustainable forestry,
> ... efficient fuel wood and charcoal production, ...
> and designing and distributing efficient stoves." I
> believe that these are essential, not only for the
> welfare of humankind, but also for the welfare of
> other living creatures, and even non-living entities,
> such as the air, the waters, the soils, the rocks and
> mountains, even the earth itself.
>
> This forum may be an example of the phenomenon that
> "the whole sometimes is greater than the sum of its
> parts." Knowing that I am not alone encourages me to
> keep trying. I know that I cannot make much of a
> difference but perhaps between all of us, we can leave
> a mark on that which is yet to be.
>
>
> Dick Boyt
> rdboyt@yahoo.com
> 20479 Panda Rd
> Neosho, MO 64850
>
>
> __________________________________
> Do you Yahoo!?
> The New Yahoo! Search - Faster. Easier. Bingo.
> http://search.yahoo.com
>

From andrew.heggie at DTN.NTL.COM Fri May 23 09:46:25 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:23 2004
Subject: Burning rubber
In-Reply-To: <005101c320e9$f913d080$0c41083e@dell>
Message-ID: <FRI.23.MAY.2003.144625.0100.>

On Fri, 23 May 2003 08:12:55 +0300, elk wrote:

>Be brutal! Am I dreaming? Could we do this? Is rubber a suitable alternative
>fuel for our attention?

My personal feeling is that it is not practical on the small scale,
there are too many possible pollutants if you get it wrong, to do it
with confidence would require careful monitoring that would not be
worthwhile below the 100kW(t) level. However knowing you I have no
wish to put you off the endeavour ;-).

AJH

From kchisholm at CA.INTER.NET Fri May 23 10:26:00 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:23 2004
Subject: Burning rubber
Message-ID: <FRI.23.MAY.2003.112600.0300.KCHISHOLM@CA.INTER.NET>

Dear Andrew

Is it perhaps a case of when you do it wrong and create pollution, there is
ALWAYS smoke and toxics, but if you do it right, there is NEVER smoke or
toxics?

If this was the case, then the task is readily defined: Make a tire burning
stove that does not smoke. Whether or not this can be done is another
matter, but at least there is a clear statement of the task to be
accomplished, and clear "rules" or "indicators" of success or failure.

Kevin

PS: Thanks very much for your alerts on the Hydrofluoric Acid hazard. I had
not realized that the stuff was so deadly dangerous. See also:
http://www.bu.edu/es/LabSafety/ESMSDSs/MSHydFluoricAcid.html

It is interesting to compare the MSDS for Hydrochloric Acid:
http://www.bu.edu/es/LabSafety/ESMSDSs/MSHydFluoricAcid.html

It is very much safer.

Kevin

----- Original Message -----
From: "Andrew Heggie" <andrew.heggie@dtn.ntl.com>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Friday, May 23, 2003 10:46 AM
Subject: Re: [STOVES] Burning rubber

> On Fri, 23 May 2003 08:12:55 +0300, elk wrote:
>
> >Be brutal! Am I dreaming? Could we do this? Is rubber a suitable
alternative
> >fuel for our attention?
>
> My personal feeling is that it is not practical on the small scale,
> there are too many possible pollutants if you get it wrong, to do it
> with confidence would require careful monitoring that would not be
> worthwhile below the 100kW(t) level. However knowing you I have no
> wish to put you off the endeavour ;-).
>
> AJH

From snkm at BTL.NET Fri May 23 12:04:59 2003
From: snkm at BTL.NET (Peter Singfield)
Date: Tue Aug 10 18:30:23 2004
Subject: Burning rubber
Message-ID: <FRI.23.MAY.2003.100459.0600.SNKM@BTL.NET>

Dear All;

I worked with car tire "pellets" many years ago. Hand processing car tire
into little chunks (2 in square) is no more labor intensive (in regards to
btu's derived) work than cutting/splitting wood.

Tires are easy to cut with a sharp knife when submerged in water. In this
manner both side "irons" can be quickly separated from the main carcass.

The side walls are then separated from the "tread" in this same manner --
and are also easily cut into long strips -- then squared to "chunks".

The treat of modern tires is mostly always steel belted these days -- and
that creates problems.

#1: -- poorer fuel value (much steel be there)

#2: -- cutting fine steel wire embedded in rubber

#3: -- due to #1 -- much "ash"

There are also belted tires with fiberglass -- and combinations of both.

The tread is best "chopped" up using a good axe on a solid hardwood
"block". And is far more labor intensive for BTU's resolved.

Once you have reduced a tire into small chunks it is quite easy to burn
these completely and safely -- one or two "chunks" at a time in a small --
yet surprisingly powerful -- stove. It is a most amazingly "rich" fuel!!

I had built a small pyrolizing unit -- that burned the gasses of pyrolysis.
Which are exceptionally high btu value.

I used a double grating -- course and finer.

The result was clean bare metal -- clean bare fiberglass -- and excellent
pure charcoal "dust" -- plus lot's of heat.

This was but a bench prototype for a larger tire processing system -- that
was never continued.

But the bench prototype was a wonder to behold when in operation.

The huge problem for commercializing such projects on large scale is tire
processing. Tire shredders are very expensive -- very energy use intensive
-- and very high maintenance.

There was even "talk" of super cooling tires in liquid nitrogen to then
allow easy break up!!

But for people in need of cooking fuel where scrap tires are piling up --
amazing fuel if processed simply as described above.

The heat of combustion is so intense that smelting iron with this fuel is
easy. so yes -- great foundry fuel.

When used for such purposes -- in a properly designed "stove" --
temperatures are so high I doubt any complicated toxic molecules can survive.

Zinc Oxide should be trapped -- injection of a water mist into and off-set
chimney??

Peter Singfield
Belize

At 11:26 AM 5/23/2003 -0300, you wrote:
>Dear Andrew
>
>Is it perhaps a case of when you do it wrong and create pollution, there is
>ALWAYS smoke and toxics, but if you do it right, there is NEVER smoke or
>toxics?
>
>If this was the case, then the task is readily defined: Make a tire burning
>stove that does not smoke. Whether or not this can be done is another
>matter, but at least there is a clear statement of the task to be
>accomplished, and clear "rules" or "indicators" of success or failure.
>
>Kevin
>
>PS: Thanks very much for your alerts on the Hydrofluoric Acid hazard. I had
>not realized that the stuff was so deadly dangerous. See also:
>http://www.bu.edu/es/LabSafety/ESMSDSs/MSHydFluoricAcid.html
>
>It is interesting to compare the MSDS for Hydrochloric Acid:
>http://www.bu.edu/es/LabSafety/ESMSDSs/MSHydFluoricAcid.html
>
>It is very much safer.
>
>Kevin
>
>----- Original Message -----
>From: "Andrew Heggie" <andrew.heggie@dtn.ntl.com>
>To: <STOVES@LISTSERV.REPP.ORG>
>Sent: Friday, May 23, 2003 10:46 AM
>Subject: Re: [STOVES] Burning rubber
>
>
>> On Fri, 23 May 2003 08:12:55 +0300, elk wrote:
>>
>> >Be brutal! Am I dreaming? Could we do this? Is rubber a suitable
>alternative
>> >fuel for our attention?
>>
>> My personal feeling is that it is not practical on the small scale,
>> there are too many possible pollutants if you get it wrong, to do it
>> with confidence would require careful monitoring that would not be
>> worthwhile below the 100kW(t) level. However knowing you I have no
>> wish to put you off the endeavour ;-).
>>
>> AJH
>

From andrew.heggie at DTN.NTL.COM Fri May 23 14:29:27 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:23 2004
Subject: Burning rubber
In-Reply-To: <005401c32139$0d51c120$c09a0a40@kevin>
Message-ID: <FRI.23.MAY.2003.192927.0100.>

On Fri, 23 May 2003 11:26:00 -0300, Kevin Chisholm wrote:

>Dear Andrew
>
>Is it perhaps a case of when you do it wrong and create pollution, there is
>ALWAYS smoke and toxics, but if you do it right, there is NEVER smoke or
>toxics?

I remember querying Tami about this, without reply. My take on the
matter is that IF it smokes then there are bound to be pollutnats, CO
PICs as PM2.5 and others. If it does no smoke then the PM 2.5 etc may
be gone but there could well be large amounts of CO, NOx sulphur
particles, VOCs PAHs etc. So a clean burning device is within the set
of smokefree devices.
>
>If this was the case, then the task is readily defined: Make a tire burning
>stove that does not smoke. Whether or not this can be done is another
>matter, but at least there is a clear statement of the task to be
>accomplished, and clear "rules" or "indicators" of success or failure.

I have made a tyre burning device that does not appear to smoke to a
casual observer however on reading the pdf on the url I quoted to ELK
you will see there are many other problems.

I am not a chemist so I cannot readily see how the various toxic
chemicals form, suffice to say that once furfurans and dioxins have
formed (at temperatures of around 350C) from undefined chemicals in
the tyre they are not substantially destroyed until temperatures of
1300C are attained. AFAIK you are unlikely to reach these temperatures
in a small cooking stove at all and even if you did heat losses from
quenching surfaces would prevent all the massflow being subject to
such heat.

Now my understanding is that there is a small proportion of wood that
is in the form of six carbon atoms in a ring, the vast majority of the
bonds are linear and simple c-c c=c c-o c-h and o-h bonds. Vulcanised
rubber has many ring type structures which require higher temperatures
to break as well as sulphur compounds. These structures are the basis
of the polycyclic aromatic compounds that are implicated as
carcinogens.

As with polluted wood, I can see a way that might enable cleaner
burning but not practically at the small scale, even if you vent the
pollutants out of the kitchen they will still settle somewhere. As I
said before, just because I see it as difficult should not mean it is
not looked at, tests in the real world may well prove me wrong, in UK
it would appear to be a futile quest as regulations would make
licensing the device so expensive to be not worthwhile.

AJH

From crispin at NEWDAWN.SZ Fri May 23 16:06:07 2003
From: crispin at NEWDAWN.SZ (Newdawn (Africa Online))
Date: Tue Aug 10 18:30:23 2004
Subject: Burning rubber
Message-ID: <FRI.23.MAY.2003.220607.0200.CRISPIN@NEWDAWN.SZ>

Dear Stovers

I am reading this with interest as I have my son Nigel with me from China
for an anti-SARS visit.

He says that there are something like 27 chemicals/ingredients in tires and
the number of reactions that can go on is pretty high. He recommends a
large, continuous, well monitored process only.

He also says that the energy in the large number of double bonded carbons is
very high, as attested by other contributors. To get them apart it takes a
lot of energy and it releases a lot as well. If the temperatures can be
raised high enough it will burn properly, it certainly looks as if refactory
materials will be required. Metals that can survive 1500 C are very
expensive, stainless steel not being one of them.

Perhaps a better application than cooking stoves is firing pottery to make
stoves. The energy available and the temperatures required to burn the
ghastly substances in the tires and the temperatures required by the pottery
makers all seem to coincide.

Tires seem well suited to firing high quality stove bodies. Perhaps
Vivienne Abbott can comment if she has time. Would rural Malawi be a place
where this might work? The fuel wood for firing stoves is a real expense in
some places. Perhaps one tire would fire quite a number of stoves.

Regards
Crispin

From elk at WANANCHI.COM Mon May 19 05:39:11 2003
From: elk at WANANCHI.COM (elk)
Date: Tue Aug 10 18:30:23 2004
Subject: Burning rubber
Message-ID: <MON.19.MAY.2003.123911.0300.ELK@WANANCHI.COM>

Stovers;

It's clear the burning rubber as fuel in a kitchen may be too toxic/pollutant. I guess the argument that a good percentage of old tires end up being burnt slowly, smokily and at low temperatures as waste- either deliberately or accidentally- is insufficient justification to run the risk of introducing this type of pollution into the cooking environment. However- I hope we can come up with something practical in any case. Peter Singfield's advice on processing tires into fuel pellets is of help, and the manual effort sounds insignificant in the local context- e.g. the value of labour V.S. the cost of fuel, especially the calorific value of rubber.

Maybe other uses for the heat can be found- like drying biomass prior to carbonisation? There are many potential applications for a small, clean-burning rubber combustion units outside of the kitchen. If rubber can be legally used in the manufacture of cement within developed nations, then maybe it can be used to bake coral into lime in developing countries for example? Far too many mangrove forests are being damaged here in Kenya to provide fuel for this unregulated industry. Crispin suggests using is a fuel for ceramic kilns- that's another possibility.

I would guess that a small clean-burning stand-alone rubber-burning furnace the size of a 200 gal. drum, using a ceramic combustion chamber could have thousands of applications. Any estimates on the power a stove such as this that could burn maybe 20 kg rubber per hour would produce in the form of useable energy? If we're now out of the kitchen, then we may as well scale the 'stove' up somewhat.

Now- once again, how can we build this? Do we need a fan, or will a tall chimney provide sufficient flue draught to draw enough air into the combustion chamber to produce a hot- hence clean- burn? We can consider how to capture the heat later maybe......

rgds;
elk
----------------------------------------------
Elsen L.Karstad, Nairobi Kenya
elk@wananchi.com
http://www.chardust.com/

----- Original Message -----
From: Newdawn (Africa Online)
To: elk
Sent: Friday, May 23, 2003 12:52 PM
Subject: Re: [STOVES] Burning rubber

Dear Stovers

I had a call from a guy in Namibia yesterday and he says that they are
experimenting with burning old engine oil as a stove fuel. There is a
product called a Geyser 2000 which is a paraffin burning vertical tube for
heating water. It uses a wick and a 2 metre draft to create a fast and
clean paraffin fire without a fan. This oil burning is apparently aimed at
reproducing that effect but I hear it is still pretty smokey. He has
converted a Vesto to burn oil.

In Windhoek there is a geat deal of car engine oil and very little wood.
Farms also have a lot of engine oil from tractors and there is no one
recycling oil in Namibia so it is simply thrown onto the ground. Huge
resources are tossed in a polluting manner.

What are the environmental implications for the cook when burning old engine
oil (with metals and varnishes etc in it)?

Regards
Crispin

From entre16 at INTELNET.NET.GT Sun May 25 07:59:31 2003
From: entre16 at INTELNET.NET.GT (Derick Calderon)
Date: Tue Aug 10 18:30:23 2004
Subject: Why I do what I do
Message-ID: <SUN.25.MAY.2003.065931.0500.ENTRE16@INTELNET.NET.GT>

Dear Tom: I think your efforts and those of others trying to acheive the
best results in regards to stoves are very important to those who have low
effciency cooking efforts.

I think a major effort should be done by others to communicate the necessary
information to use the best stoves to all those that need it.

Wishing you success.

Fundahabitat
Derick Calderon
Tel 502 3671197 Fax 502 3671196
7 Ave 15-79 Guatemala 001010
----- Original Message -----
From: "Tom Reed" <tombreed@attbi.com>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Friday, May 23, 2003 12:32 AM
Subject: Re: [STOVES] Why I do what I do

> Dear Thomas, Dick and All:
>
> The billions of people cooking primitively with wood for thousands of
years
> had no choice (and plenty of wood). Half the world has now moved on to a
> point where we know a great deal more about combustion. So, in an effort
to
> improve the lot of the others we are all applying our knowledge to making
> better stoves. Nothing arrogant about that.
>
> Personally, I consider myself an innovative (not band aid) inventor in the
> field of thermal processes, and as such consider it my duty and pleasure
to
> help.
>
> Onward, TOM REED
>
>
>
>
> Dr. Thomas B. Reed
> 1810 Smith Rd., Golden, CO 80401
> tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
> ----- Original Message -----
> From: "Richard Boyt" <rdboyt@YAHOO.COM>
> To: <STOVES@LISTSERV.REPP.ORG>
> Sent: Thursday, May 22, 2003 6:17 AM
> Subject: [STOVES] Why I do what I do
>
>
> > Dear Thomas Stubbing and Stovers,
> >
> > The question "why do I do what I'm doing" is troubling
> > because for me, at least, it is also an accusation.
> >
> > Is it not remarkable arrogance for some smart-ass
> > local yokel from back woods Podunk Center to believe
> > that he knows more than millions of people who live
> > half way around the world on how to build their fires,
> > or make their stoves, or cook their food? Is it not
> > true that these millions have successfully survived
> > for millenia by observing the traditions passed down
> > to them by a thousand generations of ancestors?
> >
> > And so I search for some justification for my belief
> > that I can help them. As problems change, so must
> > solutions. World resources that used to fill the
> > needs of five million people cannot sustainably fill
> > the needs of five billion plus- and growing
> > exponentially. Our present dependence on fossil fuels
> > for energy is clearly not sustainable. I too, am
> > greatly interested in searching for solutions to
> > problems in the areas of "... sustainable forestry,
> > ... efficient fuel wood and charcoal production, ...
> > and designing and distributing efficient stoves." I
> > believe that these are essential, not only for the
> > welfare of humankind, but also for the welfare of
> > other living creatures, and even non-living entities,
> > such as the air, the waters, the soils, the rocks and
> > mountains, even the earth itself.
> >
> > This forum may be an example of the phenomenon that
> > "the whole sometimes is greater than the sum of its
> > parts." Knowing that I am not alone encourages me to
> > keep trying. I know that I cannot make much of a
> > difference but perhaps between all of us, we can leave
> > a mark on that which is yet to be.
> >
> >
> > Dick Boyt
> > rdboyt@yahoo.com
> > 20479 Panda Rd
> > Neosho, MO 64850
> >
> >
> > __________________________________
> > Do you Yahoo!?
> > The New Yahoo! Search - Faster. Easier. Bingo.
> > http://search.yahoo.com
> >
>

From ronallarson at QWEST.NET Sun May 25 10:35:11 2003
From: ronallarson at QWEST.NET (Ron Larson)
Date: Tue Aug 10 18:30:23 2004
Subject: Why I do what I do
In-Reply-To: <200305221137.h4MBbOo31465@ns1.repp.org>
Message-ID: <SUN.25.MAY.2003.083511.0600.RONALLARSON@QWEST.NET>

Richard:

1. As someone who has visited you and know of you unique talents, I want
to say that we appreciate greatly your interest in the world of stoves. I
think we know why you do as well.

2. I have several technical questions for you. First, you were one of
the first to build a charcoal-making stove and were kind enough to send me
and others a unique "ten-can" version using scrap metal cans. But your
recent messages on ceramics have inspired me to make a ceramic version of
the same for testing at Dean Still's "soiree" in about a week. I am not at
all happy with my efforts. I'd appreciate hearing how you might design one
like your earlier work - but now all in clay.

3. I find the biggest difficulty is in getting a firm solid structure
(also true for the two-can approach). I have one design in two parts - like
the two can approach, but these are both double-walled (nominal 1/4"
thickness - about 6-7 mm). They have a large flat lip at each end - with
three holes in each to "tie" or pin together. I will be able to control
primary and secondary air separately and of course capture waste heat from
each (the entry holes are at the exterior top in each case - with entry at
interior lower levels). This was made by me using slab roller techniques -
starting with eight suitably sized flat pieces which I "draped" (around
logs) until hardened a bit and then "welded" together, and added the
washer-shaped pieces at each end. Easy enough for anyone with a slab
roller - and I can see banging these out pretty fast after a system got
going. I am afraid of the differential expansions I expect to see and fear
they may break - but worth a try. I wish I could send a picture or photo -
but hope the above may explain what I am attempting - and asking your
opinion on. This differs from the metal can approach only in the attempt to
get better insulation and air pre-heat using the double wall design. I
think stability is more easily and cheaply obtained with the lowest added
"washer". (Maybe still too breakable.)

4. The second approach uses several pieces that Gretchen has THROWN for
me - and which I "welded" together. Now I have only one thickness
throughout. Both top and bottom are conical. The bottom one is conical to
get a broad base for stability. The top one is to allow pots of various
sizes to nest inside and provide a taller chimney, aconvective heat enhancer
and wind shield. In between is the usual short narrower cylindrical
"chimney-combustion" section, with secondary air holes punched through at
the bottom (using an off-axis air entry design to get "swirl" hopefully). I
expect to put scrap metal heat reflectors around the upper cone to get the
benefits of heating the secondary air - not fully worked out yet. Overall,
this has some of the flavor of an "hourglass" shape. Now the problem is to
get a reasonably good fit between a separate lower interior "fuel chamber"
that I expect to light separately and then place the bigger "hourglass" on
top of (or possibly lighting after asssembly). If needed, either a hole or
mound can be used to get the interior fuel container at the right height.
As you can see, I am not happy with this "Rube Goldberg" approach. I have a
reasonably stable design, but too much difficulty I think for the cook in
prepositioning. The problem I am trying to solve is having a means also of
extinguishing easily at the end of the pyrolysis phase. I know I don't have
the solution yet.

5. Like you, I think there is plenty of room for improved use of ceramics
for stoves, and many will appreciate your continued efforts - especially
among the many developing country potters who can eventually duplicate a
satisfactory design. I have greatly enjoyed your series and look forward to
more. Somewhere in that process, I hope you (and others) will try again the
charcoal-making stove - but all in clay this time.

Ron

>-----Original Message-----
>From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On
>Behalf Of Richard Boyt
>Sent: Thursday, May 22, 2003 6:18 AM
>To: STOVES@LISTSERV.REPP.ORG
>Subject: Why I do what I do
>
>
>---------------------- Information from the mail header
>-----------------------
>Sender: The Stoves Discussion List <STOVES@LISTSERV.REPP.ORG>
>Poster: Richard Boyt <rdboyt@YAHOO.COM>
>Subject: Why I do what I do
>-------------------------------------------------------------------
>------------
>
>Dear Thomas Stubbing and Stovers,
>
>The question "why do I do what I'm doing" is troubling
>because for me, at least, it is also an accusation.
>
>Is it not remarkable arrogance for some smart-ass
>local yokel from back woods Podunk Center to believe
>that he knows more than millions of people who live
>half way around the world on how to build their fires,
>or make their stoves, or cook their food? Is it not
>true that these millions have successfully survived
>for millenia by observing the traditions passed down
>to them by a thousand generations of ancestors?
>
>And so I search for some justification for my belief
>that I can help them. As problems change, so must
>solutions. World resources that used to fill the
>needs of five million people cannot sustainably fill
>the needs of five billion plus- and growing
>exponentially. Our present dependence on fossil fuels
>for energy is clearly not sustainable. I too, am
>greatly interested in searching for solutions to
>problems in the areas of "... sustainable forestry,
>... efficient fuel wood and charcoal production, ...
>and designing and distributing efficient stoves." I
>believe that these are essential, not only for the
>welfare of humankind, but also for the welfare of
>other living creatures, and even non-living entities,
>such as the air, the waters, the soils, the rocks and
>mountains, even the earth itself.
>
>This forum may be an example of the phenomenon that
>"the whole sometimes is greater than the sum of its
>parts." Knowing that I am not alone encourages me to
>keep trying. I know that I cannot make much of a
>difference but perhaps between all of us, we can leave
>a mark on that which is yet to be.
>
>
>Dick Boyt
>rdboyt@yahoo.com
>20479 Panda Rd
>Neosho, MO 64850
>
>
>__________________________________
>Do you Yahoo!?
>The New Yahoo! Search - Faster. Easier. Bingo.
>http://search.yahoo.com
>
>

From tmiles at TRMILES.COM Sun May 25 14:36:43 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:23 2004
Subject: Greenhouse Gas Implications of Household Energy Technlogy
Message-ID: <SUN.25.MAY.2003.113643.0700.TMILES@TRMILES.COM>

The paper, Greenhouse Gas Implications of Household Energy Technology by Rob Bailis, Majid Ezzati and Daniel Kammen appeared in Environmental Science and Technology (vol 37 2003, 2051-2059) this week. It is available at EST Online for American Chemical Society Members.

How Charcoal Fires Heat the World, an article based on the study, can be viewed at EST Online http://pubs.acs.org/subscribe/journals/esthag-w/2003/apr/tech/kb_kenya.html

Tom Miles

From rdboyt at YAHOO.COM Mon May 26 00:04:49 2003
From: rdboyt at YAHOO.COM (Richard Boyt)
Date: Tue Aug 10 18:30:23 2004
Subject: Ceramic for Stoves Part 3a- Test firing local clays- primitive
kilns
Message-ID: <SUN.25.MAY.2003.210449.0700.RDBOYT@YAHOO.COM>

Again, greetings from Pottershop Holler (old maps).
Much of this was written under a week of tornado
watches and warnings, but at this moment the sun is
brilliant and the sky a deep blue even to the
horizons.

First, I want to thank the several people who have
encouraged me to continue this journey.

It will be useful to know how the samples of clays
collected in Part 2 will respond to the high
temperatures that can be reached in the combustion
chambers of stoves. I have the luxury of various
electric kilns capable of reaching more than 1100
degrees C (2,000 degrees F) (cone 03), in as long or
as short a period of time as I may wish. But that
violates the goal of describing firing techniques that
might be used by potters in pre-industrial rural areas
of third world countries where 30 amps of 220 volts is
only a dream. Yet, they do make and fire their pots,
and they have for thousands of years.

Historically, I know of no major culture that has not
made pottery. In fact, it can be contended that
pre-historic societies made the discovery that heating
clay to a temperature approaching red hot turns it
into a kind of stone, and that food could then be
cooked and/ or stored in pots of fired clay. This
discovery may have been instrumental in permitting
nomadic hunting tribes to practice agriculture and to
settle into villages, towns, and cities. Firing their
pots required learning how to build fires hot enough
to heat the clay to temperatures high enough to cause
it to at least partially vitrify (melt) so that water
could not soak into it and turn it back to mud, and
yet to heat it slowly enough to keep it from
shattering.

To fire a ceramic pot requires a very hot stove
(kiln), much hotter than a cook stove. It must have a
cavity inside that is large enough to hold the pot.
At the moment, however, our problem is to test fire
the small clay disks prepared in part 2. I find that
a well made bon-fire can produce a considerable
quantity of glowing char. Carefully pre heating and
then positioning the disks within a bed of glowing
char will bring them to red heat. The temperature can
then be raised by rapidly fanning the char.

While unfired clay that is dry has lost its water of
plasticity, it still contains an appreciable quantity
of water that is chemically held. The formula for an
ideal clay is Al203.2SiO2.2H2O. This water will be
removed when the clay reaches about 350 degrees C (650
degrees F). If that water cannot escape rapidly
enough from the clay as it is heated, it may build up
enough pressure to explode with a sound much like that
of popping popcorn, and your sample disk will be no
more than scrap. Therefore, the disks must be heated
slowly. How fast is too fast? The clay will let you
know, and anticipating failures is the reason I
suggested you make half a dozen disks of each clay to
be tested.

After the coals burn out and the disks have cooled,
test the disks for relative vitrification. A very
simple test can be made by touching the tip of your
damp tongue to the surface of a fired disk. Quick
absorption of moisture means that the clay is not
excessively vitrified, and could probably be safely
fired to an even higher temperature. This might make
it a candidate for use in a combustion chamber. No,
or slow absorption indicates that it might not take a
higher temperature. Obviously a disk that has melted,
bloated, or distorted will likely only be useful in
spaces that do not get very hot.

Having fired your several disks samples, you now have
a pretty good idea of whether you can use the clay
samples you have found, or if you need to look for a
different source. In any case, you will need to dig,
slurry, settle and/or strain about 5 kilos (11 pounds)
of clay and start removing enough water by absorption
and/or evaporation to cause it to reach a plastic
consistency. You will need this clay later for
further testing and for construction of a kiln in
which you will be able to fire the ceramic parts for a
cook stove.

Most literature I have read contends that the earliest
pottery kilns were pits dug into the ground, lined
with limbs and branches onto which pots were stacked.
More branches were piled on top, followed by a
shingling layer of pieces of broken pots. Set afire,
it burns slowly, probably smoked a lot, and when I
tried it, never heated the pots much more than enough
to get rid of the chemically held water. My pots
ended up being quite porous. That is OK for cooling
water by evaporation, but not so good for cooking.

A somewhat later design is thought to be a kiln in a
hill. It is a lot of work to make, but it can reach
higher temperatures. Burrow into the side of the hill
and cut a hole up through the top to serve as a
chimney. Place the pots on a grate above the fuel so
that they will be submerged in flame. Add fuel as
needed and be prepared to spend hours or even days of
stoking. I built one, but it was so slow in heating
that after two days of warming up all the surrounding
damp earth, I gave up. In later developments, kilns
were built above ground with walls of stone, brick,
and mud, and again a roof of shards from pots that
hadn't made it.

But I'm looking for something quite different-- an
inexpensive, light weight, easy-to-build, portable
kiln, just big enough fire the ceramic parts for an
inexpensive, light weight, easy-to-build, portable
cook stove.

The next submission I'm working on (Part 3B) is a
surprisingly simple (natural) design for a stove/kiln
that I have stumbled upon. It is so simple and
obvious that I think early people must have used it.
Apparently no traces of this kiln design have been
found, perhaps because it literally destroys itself in
the firing.

I hope this proves useful.

Dick Boyt
rdboyt@yahoo.com
20479 Panda Rd
Neosho, MO 64850

__________________________________
Do you Yahoo!?
The New Yahoo! Search - Faster. Easier. Bingo.
http://search.yahoo.com

From ventfory at IAFRICA.COM Tue May 27 04:27:45 2003
From: ventfory at IAFRICA.COM (Kobus)
Date: Tue Aug 10 18:30:23 2004
Subject: Charcoal fires heat the world
Message-ID: <TUE.27.MAY.2003.102745.0200.VENTFORY@IAFRICA.COM>

Tom M and stovers,

As I am still perfecting charcoal gasification, I found the link that Tom M provided held a special relevance to my experimentation.
http://pubs.acs.org/subscribe/journals/esthag-w/2003/apr/tech/kb_kenya.html

We all know that charcoal burning by households is less favourable since it can lead to deforestation and this new research confirms that charcoal burning also contributes to the greenhouse effect, through its non-CO2 greenhouse gas emissions.

The report shows that when you calculate and analyse the emissions of carbon monoxide and methane (CH4) in a global warming context (grams of carbon in 20-year CO2 equivalent units) charcoal burning constitutes a higher green house gas component to global warming than traditional three-stone wood fires or improved ceramic woodstoves. And to add to the problem, greenhouse gas emissions from producing charcoal is reportedly 6 times higher than the emissions from woodstoves on a gram of carbon per kilogram of fuel burnt basis.

So even though 250 million people happily cook on charcoal (according to the report), non-CO2 emissions are causing damage to the environment and affecting peoples health, perhaps not in PPM concentrations, but due to the adsorption by the bloodstream of harmful CO.

For me, a novice in the field of small gasification stoves, biomass gasification clearly holds the answer, with H2, CO and CH4 emitted being immediately bunt off in a secondary burn and not just vented and warming the atmosphere. The charcoal as a result of the process is a by-product, but still utilizable.

It is unlikely that people will simply switch from charcoal burning to biomass gasification (due to the social component and availability of fuels etc.) in the short term, but most obstacles can be overcome in the long run.

A short term solution to eliminate non-CO2 emissions from charcoal, could be to introduce efficient industrial (or efficient "backyard") wood pyrolysing technologies of waste products (nut hulls, coffee husks, bagasse, manure, sawdust, sawmill waste, plantation waste) perhaps also densified.

-and then-
introduce the resultant charcoal to households in conjunction with a true charcoal gasifier that can burn up the non-CO2 greenhouse gases.

In summary I deduct that charcoal burning in households does reduce particulate matter concentrations, thereby decreasing lower respiratory infection rates, but so does small biomass- and charcoal gasifying stoves and without the release of non-CO2 greenhouse gases.

Regards

Kobus
ventfory@iafrica.com

From tmiles at TRMILES.COM Wed May 28 01:48:52 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:23 2004
Subject: Charcoal fires heat the world
Message-ID: <WED.28.MAY.2003.014852.0400.TMILES@TRMILES.COM>

It would be interesting to see how the ceramic-lined wood stoves in this
study (See pictures at: http://www.rff.org/%7eezzati/stoves.html and links
from
http://www.repp.org/discussiongroups/resources/stoves/Countries/country.htm
l)compare with the ceramic-lined stove being made by Richard Henya.
http://www.repp.org/discussiongroups/resources/stoves/Njagu/henyastove.html
His firebox and stack are more confined than the Kuni Mbili, Upesi and
Lira stoves that were tested.

I was reminded by the article of Dana Charron's recommendation at the
January ETHOS meeting that we try to get more improved stoves incorporated
into health and emissions studies.

I was struck by how stove use evened out differences between stoves on
overall emissions. Do people in Southern Africa, Central America, Asia or
in the mountain areas keep fires burning or smouldering all day when not
cooking? Do cooking habits change when people accept and use more
efficient stoves?

Tom

From rstanley at LEGACYFOUND.ORG Tue May 20 08:49:38 2003
From: rstanley at LEGACYFOUND.ORG (Richard Stanley)
Date: Tue Aug 10 18:30:24 2004
Subject: test message to stoves group
Message-ID: <TUE.20.MAY.2003.154938.0300.>

Tom,

Pls check to se if it came through. I am still not seegin anything on my screen indicating that what I post is getting out there.

Thanks,

Richard Stanley

Tom Miles wrote:

> The paper, Greenhouse Gas Implications of Household Energy Technology by Rob Bailis, Majid Ezzati and Daniel Kammen appeared in Environmental Science and Technology (vol 37 2003, 2051-2059) this week. It is available at EST Online for American Chemical Society Members.
>
> How Charcoal Fires Heat the World, an article based on the study, can be viewed at EST Online http://pubs.acs.org/subscribe/journals/esthag-w/2003/apr/tech/kb_kenya.html
>
> Tom Miles

From andrew.heggie at DTN.NTL.COM Wed May 28 04:04:09 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:24 2004
Subject: Burning rubber
In-Reply-To: <001c01c32167$7d093790$36d0fea9@desmond>
Message-ID: <WED.28.MAY.2003.090409.0100.>

An Earlier reply I made to Crispin, the reply to address is still
catching me out:

On Fri, 23 May 2003 22:06:07 +0200, Newdawn (Africa Online) wrote:

>
>He says that there are something like 27 chemicals/ingredients in tires and
>the number of reactions that can go on is pretty high. He recommends a
>large, continuous, well monitored process only.

Some agreement then.
>
>He also says that the energy in the large number of double bonded carbons is
>very high, as attested by other contributors. To get them apart it takes a
>lot of energy and it releases a lot as well.

I was under the impression that their being in benzene rings was what
contributed to their stability.

> If the temperatures can be
>raised high enough it will burn properly, it certainly looks as if refactory
>materials will be required. Metals that can survive 1500 C are very
>expensive, stainless steel not being one of them.

But of course there are other means of maintaining high flame
temperatures without recourse to heavyweight components, though I
grant they will often require high cost alloys.
>
>Perhaps a better application than cooking stoves is firing pottery to make
>stoves. The energy available and the temperatures required to burn the
>ghastly substances in the tires and the temperatures required by the pottery
>makers all seem to coincide.

Since talking to Ronal about firing pottery with flue gases it's
struck me that it is a wasteful process. Little of the heat energy is
required to vitrify the clay but an awfully large amount is required
in bringing the pots to temperature and maintaining them there. If you
looked at the mass flow and temperature over time then I imagine the
exhaust from the kilns has still a lot of ability to do work. This is
why electrically heated kilns can be worthwhile, there is no mass flow
through them so no waste in the flue gases.

AJH

From andrew.heggie at DTN.NTL.COM Wed May 28 04:04:14 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:24 2004
Subject: test message to stoves group
In-Reply-To: <3ECA2454.CD622CC5@legacyfound.org>
Message-ID: <WED.28.MAY.2003.090414.0100.>

On Tue, 20 May 2003 15:49:38 +0300, Richard Stanley wrote:

>Tom,
>
>Pls check to se if it came through. I am still not seegin anything on my screen indicating that what I post is getting out there.

It got here, I had the same problem, you need to go to the repp site
and change the defaults to send you a copy of your own message rather
than an acknowledgement of your posting.

AJH

From elk at WANANCHI.COM Wed May 28 04:57:33 2003
From: elk at WANANCHI.COM (elk)
Date: Tue Aug 10 18:30:24 2004
Subject: Energy in V.S. out.....
Message-ID: <WED.28.MAY.2003.115733.0300.ELK@WANANCHI.COM>

I heard a curious fact a while ago, but I have not yet
been able to establish the truth of it. 'Solar electric
panels NEVER in their lifetime produce the amount of
energy that it takes to manufacture them.'

Can this be true?

elk

--------------------------
Elsen L. Karstad
elk@wananchi.com
www.chardust.com
Nairobi Kenya

From ronallarson at QWEST.NET Wed May 28 08:22:24 2003
From: ronallarson at QWEST.NET (Ron Larson)
Date: Tue Aug 10 18:30:24 2004
Subject: Energy in V.S. out.....
In-Reply-To: <200305281110.h4SBAmo04389@ns1.repp.org>
Message-ID: <WED.28.MAY.2003.062224.0600.RONALLARSON@QWEST.NET>

Hi Elsen:

You asked:

See: http://www.nrel.gov/ncpv/pdfs/24596.pdf

I used to work with this US national group and believe this sort of
rebuttal information (Energy payback time of 1 to 4 years) only appears for
public release when thoroughly reviewed. I have seen even lower numbers -
that may be more recent. I am pretty sure that the number goes down more
when talking about concentrating PV. Wind system paybacks are cited in
terms of months.

If you or anyone can give the exact location where false information like
you cite exists, I'd like to hear about it.

Ron

From Carl.Carley at EML.ERICSSON.SE Wed May 28 09:07:06 2003
From: Carl.Carley at EML.ERICSSON.SE (Carl Carley (EMP))
Date: Tue Aug 10 18:30:24 2004
Subject: Energy in V.S. out.....
Message-ID: <WED.28.MAY.2003.150706.0200.CARL.CARLEY@EML.ERICSSON.SE>

I've heard the same about lead acid batteries, is this true anyone?

carl

-----Original Message-----
From: Ron Larson [mailto:ronallarson@QWEST.NET]
Sent: 28 May 2003 13:22
To: STOVES@LISTSERV.REPP.ORG
Subject: Re: [STOVES] Energy in V.S. out.....

Hi Elsen:

You asked:

See: http://www.nrel.gov/ncpv/pdfs/24596.pdf

I used to work with this US national group and believe this sort of rebuttal information (Energy payback time of 1 to 4 years) only appears for public release when thoroughly reviewed. I have seen even lower numbers - that may be more recent. I am pretty sure that the number goes down more when talking about concentrating PV. Wind system paybacks are cited in terms of months.

If you or anyone can give the exact location where false information like you cite exists, I'd like to hear about it.

Ron

From hseaver at CYBERSHAMANIX.COM Wed May 28 09:44:16 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:24 2004
Subject: Energy in V.S. out.....
In-Reply-To: <E3117AE4EC45D511BEC10002A55CB09C01A2BE9C@eukbant102.uk.eu.ericsson.se>
Message-ID: <WED.28.MAY.2003.084416.0500.HSEAVER@CYBERSHAMANIX.COM>

Lead acid batteries produce no power at all, they only store power, so it's
not a like comparison. It is true, however, that batteries are not very
efficient energy storage medium, and not just the lead/acid variety, which is
why net metering has caught on so well.

On Wed, May 28, 2003 at 03:07:06PM +0200, Carl Carley (EMP) wrote:
> I've heard the same about lead acid batteries, is this true anyone?
>
> carl
>
> -----Original Message-----
> From: Ron Larson [mailto:ronallarson@QWEST.NET]
> Sent: 28 May 2003 13:22
> To: STOVES@LISTSERV.REPP.ORG
> Subject: Re: [STOVES] Energy in V.S. out.....
>
>
> Hi Elsen:
>
> You asked:
>
> >I heard a curious fact a while ago, but I have not yet
> >been able to establish the truth of it. 'Solar electric
> >panels NEVER in their lifetime produce the amount of
> >energy that it takes to manufacture them.'
> >
> >Can this be true?
> >
> >elk
>
>
> See: http://www.nrel.gov/ncpv/pdfs/24596.pdf
>
> I used to work with this US national group and believe this sort of rebuttal information (Energy payback time of 1 to 4 years) only appears for public release when thoroughly reviewed. I have seen even lower numbers - that may be more recent. I am pretty sure that the number goes down more when talking about concentrating PV. Wind system paybacks are cited in terms of months.
>
> If you or anyone can give the exact location where false information like you cite exists, I'd like to hear about it.
>
> Ron

--
Harmon Seaver
CyberShamanix
http://www.cybershamanix.com

From Carl.Carley at EML.ERICSSON.SE Wed May 28 10:05:03 2003
From: Carl.Carley at EML.ERICSSON.SE (Carl Carley (EMP))
Date: Tue Aug 10 18:30:24 2004
Subject: Energy in V.S. out.....
Message-ID: <WED.28.MAY.2003.160503.0200.CARL.CARLEY@EML.ERICSSON.SE>

What I meant was for the life of the battery it will never be able to store the equivalent energy that went into its manufacture.

-----Original Message-----
From: Harmon Seaver [mailto:hseaver@CYBERSHAMANIX.COM]
Sent: 28 May 2003 14:44
To: STOVES@LISTSERV.REPP.ORG
Subject: Re: [STOVES] Energy in V.S. out.....

Lead acid batteries produce no power at all, they only store power, so it's not a like comparison. It is true, however, that batteries are not very efficient energy storage medium, and not just the lead/acid variety, which is why net metering has caught on so well.

On Wed, May 28, 2003 at 03:07:06PM +0200, Carl Carley (EMP) wrote:
> I've heard the same about lead acid batteries, is this true anyone?
>
> carl
>
> -----Original Message-----
> From: Ron Larson [mailto:ronallarson@QWEST.NET]
> Sent: 28 May 2003 13:22
> To: STOVES@LISTSERV.REPP.ORG
> Subject: Re: [STOVES] Energy in V.S. out.....
>
>
> Hi Elsen:
>
> You asked:
>
> >I heard a curious fact a while ago, but I have not yet
> >been able to establish the truth of it. 'Solar electric panels NEVER
> >in their lifetime produce the amount of energy that it takes to
> >manufacture them.'
> >
> >Can this be true?
> >
> >elk
>
>
> See: http://www.nrel.gov/ncpv/pdfs/24596.pdf
>
> I used to work with this US national group and believe this
> sort of rebuttal information (Energy payback time of 1 to 4 years)
> only appears for public release when thoroughly reviewed. I have seen
> even lower numbers - that may be more recent. I am pretty sure that
> the number goes down more when talking about concentrating PV. Wind
> system paybacks are cited in terms of months.
>
> If you or anyone can give the exact location where false
> information like you cite exists, I'd like to hear about it.
>
> Ron

--
Harmon Seaver
CyberShamanix
http://www.cybershamanix.com

From kchisholm at CA.INTER.NET Wed May 28 09:55:59 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:24 2004
Subject: Energy in V.S. out.....
Message-ID: <WED.28.MAY.2003.105559.0300.KCHISHOLM@CA.INTER.NET>

Dear Elk

There are two issues here:
1: The "net energy balance."
2: The type of energy put in, versus the type of energy out.

For example, the cost per million BTU in coal is much less than the cost per
million BTU in JP4. So... why don't jet planes use the much cheaper coal?
The answer is very obvious.

One "bottom line" is that it comes from a central station in very large
quantities, (low cost) while the solar power comes from a small installation
in a remote location (high cost)

Another "bottom line" is that if a person pays the high cost for a solar
installation, there is a benefit which is more than worth it.

Another "bottom line" is the ratio of "total output" divided by the sum of
"manufacturing energy MINUS avoided fossil energy". If the ratio is greater
than 1, the Biosphere is a winner.

Another "bottom line" ratio is: "How much energy was I consuming BEFORE I
got the new solar installation?" divided by "How much am I consuming now,
because I could not afford to continue being a wastrel?" This is always a
very good ratio.

The final bottom line is that what you ask is a simple question with a very
complex answer. :-)

Kevin

----- Original Message -----
From: "elk" <elk@WANANCHI.COM>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Wednesday, May 28, 2003 5:57 AM
Subject: [STOVES] Energy in V.S. out.....

> I heard a curious fact a while ago, but I have not yet
> been able to establish the truth of it. 'Solar electric
> panels NEVER in their lifetime produce the amount of
> energy that it takes to manufacture them.'
>
> Can this be true?
>
> elk
>
>
>
> --------------------------
> Elsen L. Karstad
> elk@wananchi.com
> www.chardust.com
> Nairobi Kenya

From tmiles at TRMILES.COM Wed May 28 10:15:08 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:24 2004
Subject: test message to stoves group
Message-ID: <WED.28.MAY.2003.071508.0700.TMILES@TRMILES.COM>

Richard,

Your messages are making it to the list. You will find that your account
settings are set to: Acknowledgements > Receive copy of own postings or,
NOACK REPRO
See: http://listserv.repp.org/archives/stoves.html >Join or leave the list
(or change settings)

When you compose a message try putting the address stoves@listserv.repp.org
in the "To:" field instead of the "cc:" field as you did in the message
below.

Are others having the same problem of postin to the list and not receiving
either an acknowledgement or a copy of your own post? If you want a copy of
your own post go the the web archive and select the appropriate setting as
indicated above.

Tom

----- Original Message -----
From: "Richard Stanley" <rstanley@legacyfound.org>
To: "Tom Miles" <tmiles@TRMILES.COM>
Cc: <STOVES@LISTSERV.REPP.ORG>
Sent: Tuesday, May 20, 2003 5:49 AM
Subject: Re: test message to stoves group

>
>
> Tom,
>
> Pls check to se if it came through. I am still not seegin anything on my
screen indicating that what I post is getting out there.
>
> Thanks,
>
> Richard Stanley
>
>
>
>
> Tom Miles wrote:
>
> > The paper, Greenhouse Gas Implications of Household Energy Technology by
Rob Bailis, Majid Ezzati and Daniel Kammen appeared in Environmental Science
and Technology (vol 37 2003, 2051-2059) this week. It is available at EST
Online for American Chemical Society Members.
> >
> > How Charcoal Fires Heat the World, an article based on the study, can
be viewed at EST Online
http://pubs.acs.org/subscribe/journals/esthag-w/2003/apr/tech/kb_kenya.html
> >
> > Tom Miles
>
>
>
>
>

From ronallarson at QWEST.NET Wed May 28 12:38:46 2003
From: ronallarson at QWEST.NET (Ron Larson)
Date: Tue Aug 10 18:30:24 2004
Subject: Energy in V.S. out.....
In-Reply-To: <200305281323.h4SDNNo06230@ns1.repp.org>
Message-ID: <WED.28.MAY.2003.103846.0600.RONALLARSON@QWEST.NET>

Carl et al:

You are right that we should include the full system payback times. I
looked around a bit and gave up on the lead-acid battery energy inputs. You
may be right (I'm not sure) about it taking more energy than one can get
back in one battery life-cycle. I couldn't determine in a short Google
search.

But several points come to mind, in addition to the recent comment by
Harmon that using net-metering is the best option - for most PV buyers and
for society:

1. Batteries are recycled a lot.

2. It would seem a likely big energy input goes into remelting the lead
plates - that could be done with solar thermal sources - which I take to be
quite different from the usual (assumed Natural gas or Electric furnaces) -
as the solar energy is lost forever if not captured upon arrival.

3. There are new (non-lead) batteries coming along with many more cycle
capabilities - could be a substantial improvement.

4. There are other storage alternatives which intuitively seem likely to
have an acceptable energy payback time - pumped hydro, compressed air,
hydrogen, etc.

Ron

>-----Original Message-----
>From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On
>Behalf Of Carl Carley (EMP)
>Sent: Wednesday, May 28, 2003 8:05 AM
>To: STOVES@LISTSERV.REPP.ORG
>Subject: Re: Energy in V.S. out.....
>
>
>---------------------- Information from the mail header
>-----------------------
>Sender: The Stoves Discussion List <STOVES@LISTSERV.REPP.ORG>
>Poster: "Carl Carley (EMP)" <Carl.Carley@EML.ERICSSON.SE>
>Subject: Re: Energy in V.S. out.....
>-------------------------------------------------------------------
>------------
>
>What I meant was for the life of the battery it will never be able
>to store the equivalent energy that went into its manufacture.
>
>
>-----Original Message-----
>From: Harmon Seaver [mailto:hseaver@CYBERSHAMANIX.COM]
>Sent: 28 May 2003 14:44
>To: STOVES@LISTSERV.REPP.ORG
>Subject: Re: [STOVES] Energy in V.S. out.....
>
>
> Lead acid batteries produce no power at all, they only store
>power, so it's not a like comparison. It is true, however, that
>batteries are not very efficient energy storage medium, and not
>just the lead/acid variety, which is why net metering has caught
>on so well.
>
>
>
>On Wed, May 28, 2003 at 03:07:06PM +0200, Carl Carley (EMP) wrote:
>> I've heard the same about lead acid batteries, is this true anyone?
>>
>> carl
>>
>> -----Original Message-----
>> From: Ron Larson [mailto:ronallarson@QWEST.NET]
>> Sent: 28 May 2003 13:22
>> To: STOVES@LISTSERV.REPP.ORG
>> Subject: Re: [STOVES] Energy in V.S. out.....
>>
>>
>> Hi Elsen:
>>
>> You asked:
>>
>> >I heard a curious fact a while ago, but I have not yet
>> >been able to establish the truth of it. 'Solar electric panels NEVER
>> >in their lifetime produce the amount of energy that it takes to
>> >manufacture them.'
>> >
>> >Can this be true?
>> >
>> >elk
>>
>>
>> See: http://www.nrel.gov/ncpv/pdfs/24596.pdf
>>
>> I used to work with this US national group and believe this
>> sort of rebuttal information (Energy payback time of 1 to 4 years)
>> only appears for public release when thoroughly reviewed. I have seen
>> even lower numbers - that may be more recent. I am pretty sure that
>> the number goes down more when talking about concentrating PV. Wind
>> system paybacks are cited in terms of months.
>>
>> If you or anyone can give the exact location where false
>> information like you cite exists, I'd like to hear about it.
>>
>> Ron
>
>--
>Harmon Seaver
>CyberShamanix
>http://www.cybershamanix.com
>
>

From snkm at BTL.NET Wed May 28 12:44:48 2003
From: snkm at BTL.NET (Peter Singfield)
Date: Tue Aug 10 18:30:24 2004
Subject: Energy in V.S. out.....
Message-ID: <WED.28.MAY.2003.104448.0600.SNKM@BTL.NET>

At 03:07 PM 5/28/2003 +0200, you wrote:
>I've heard the same about lead acid batteries, is this true anyone?
>
>carl
>

OK --

You install an "independent" solar power plant. This requires solar panels,
batteries and an inverter.

What is the energy cost to produce all of these items??

How long will the system have to run to pay back that energy cost??

Calculate the life span of each device.

Batteries have to be replaced on a regular basis.

Now -- if everyone made their own power in this manner -- would there be
enough lead for all the batteries??

I while back I was doing a study on high pressure accumulators to replace
batteries.

New composite plastics natural gas "tanks" for fueling transport vehicles
are rated at 6000 PSI.

You can catch up quick on the potential by checking out these urls.

http://a332.g.akamai.net/f/332/936/12h/www.edmunds.com/media/news/innovation
s/hydraulic.power.assist/hpaworks.big.jpg

Browse around --

Then look at this Url:

http://www.fibacanning.com/cumulo/hybrid.htm

Now -- what to do with these systems??

How about this???

http://www.aurasystems.com/pdf/hydraulic_spec.pdf

or this??

http://www.getecinc.com/hydromax.htm

How about we stop using lead acid batteries???

Peter

From hseaver at CYBERSHAMANIX.COM Wed May 28 13:10:53 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:24 2004
Subject: Energy in V.S. out.....
In-Reply-To: <E3117AE4EC45D511BEC10002A55CB09C01A2BE9D@eukbant102.uk.eu.ericsson.se>
Message-ID: <WED.28.MAY.2003.121053.0500.HSEAVER@CYBERSHAMANIX.COM>

Yes, but it's what Ken was referring to -- if you need battery storage, there
aren't a lot of other choices. So people on the grid who want to power
themselves with wind or solar can use the grid as their battery bank, and run
their electric meter backwards, but those totally off the grid, as we were for
18 years, have to use batteries with their solar or wind units to have
workable electrics. So whether or not the batteries are efficient or not is
irrelevant.
Pumping water uphill or creating hydrogen are other solutions, of course, but
no one seems to have made them work very well either, or so it seems, else many
would be using those techniques instead of batteries.

On Wed, May 28, 2003 at 04:05:03PM +0200, Carl Carley (EMP) wrote:
> What I meant was for the life of the battery it will never be able to store the equivalent energy that went into its manufacture.
>
>
> -----Original Message-----
> From: Harmon Seaver [mailto:hseaver@CYBERSHAMANIX.COM]
> Sent: 28 May 2003 14:44
> To: STOVES@LISTSERV.REPP.ORG
> Subject: Re: [STOVES] Energy in V.S. out.....
>
>
> Lead acid batteries produce no power at all, they only store power, so it's not a like comparison. It is true, however, that batteries are not very efficient energy storage medium, and not just the lead/acid variety, which is why net metering has caught on so well.
>
>
>
> On Wed, May 28, 2003 at 03:07:06PM +0200, Carl Carley (EMP) wrote:
> > I've heard the same about lead acid batteries, is this true anyone?
> >
> > carl
> >
> > -----Original Message-----
> > From: Ron Larson [mailto:ronallarson@QWEST.NET]
> > Sent: 28 May 2003 13:22
> > To: STOVES@LISTSERV.REPP.ORG
> > Subject: Re: [STOVES] Energy in V.S. out.....
> >
> >
> > Hi Elsen:
> >
> > You asked:
> >
> > >I heard a curious fact a while ago, but I have not yet
> > >been able to establish the truth of it. 'Solar electric panels NEVER
> > >in their lifetime produce the amount of energy that it takes to
> > >manufacture them.'
> > >
> > >Can this be true?
> > >
> > >elk
> >
> >
> > See: http://www.nrel.gov/ncpv/pdfs/24596.pdf
> >
> > I used to work with this US national group and believe this
> > sort of rebuttal information (Energy payback time of 1 to 4 years)
> > only appears for public release when thoroughly reviewed. I have seen
> > even lower numbers - that may be more recent. I am pretty sure that
> > the number goes down more when talking about concentrating PV. Wind
> > system paybacks are cited in terms of months.
> >
> > If you or anyone can give the exact location where false
> > information like you cite exists, I'd like to hear about it.
> >
> > Ron
>
> --
> Harmon Seaver
> CyberShamanix
> http://www.cybershamanix.com

--
Harmon Seaver
CyberShamanix
http://www.cybershamanix.com

From Gavin at AA3GENERGI.FORCE9.CO.UK Wed May 28 14:45:54 2003
From: Gavin at AA3GENERGI.FORCE9.CO.UK (Gavin Gulliver-Goodall)
Date: Tue Aug 10 18:30:24 2004
Subject: FW: [STOVES] Energy in V.S. out.....
Message-ID: <WED.28.MAY.2003.194554.0100.GAVIN@AA3GENERGI.FORCE9.CO.UK>

Chaps,
Sorry for this but running you r meter backwards does not save fossil fuels
or emissions:
The electrical grid has to have on standby a percentage of spinning reserve
capacity ready to be switched in should any less reliable generators cut
out. This is basically a big steam power station (or several) burning coal,
gas or whatever just in case the sun goes in or the wind stops (or of
course there is a grid failure or another major power generator failure. So
for every 1kW of solar pumped back into the grid the power guys are burning
at least 1/2kW of coal just in case they have to trip in to keep your fridge
running when the sun goes out.

The arguments on energy stores need a life cycle analysis to see which has
the most cycles at what efficiency (% energy lost per cycle) against energy
cost of production. Strangely for mass produced stuff energy cost is pretty
well related to $$ cost. (assuming all other things are equal - like
everything made in the same country.

There are other issues with solar electricity panels: as I understand it
there is only one mine where the special silicon is extracted, therefore
there is a relatively limited supply, with a monopoly issue with regard to
the owner, and environmental issue with regard to the site as well as the
energy to make the things.

Another point- Solar energy isn't lost if we don't use it, it is absorbed in
to the ground- I guess if we had really efficient solar electricity panels
then covering a large area of the earths surface then there would be
localised climatic changes. Fortunately panel efficiency has a long way to
go.

Otherwise its back to the stone age for all of us!
I'll keep chipping away at my axe

Cheers
gavin

Gavin Gulliver-Goodall
3G Energi,

Tel +44 (0)1835 824201
Fax +44 (0)870 8314098
Mob +44 (0)7773 781498
E mail Gavin@3genergi.co.uk <mailto:Gavin@3genergi.co.uk>

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-----Original Message-----
From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On Behalf
Of Harmon Seaver
Sent: Wednesday, May 28, 2003 18:11
To: STOVES@LISTSERV.REPP.ORG
Subject: Re: [STOVES] Energy in V.S. out.....

Yes, but it's what Ken was referring to -- if you need battery storage,
there
aren't a lot of other choices. So people on the grid who want to power
themselves with wind or solar can use the grid as their battery bank, and
run
their electric meter backwards, but those totally off the grid, as we were
for
18 years, have to use batteries with their solar or wind units to have
workable electrics. So whether or not the batteries are efficient or not is
irrelevant.
Pumping water uphill or creating hydrogen are other solutions, of course,
but
no one seems to have made them work very well either, or so it seems, else
many
would be using those techniques instead of batteries.

On Wed, May 28, 2003 at 04:05:03PM +0200, Carl Carley (EMP) wrote:
> What I meant was for the life of the battery it will never be able to
store the equivalent energy that went into its manufacture.
>
>
> -----Original Message-----
> From: Harmon Seaver [mailto:hseaver@CYBERSHAMANIX.COM]
> Sent: 28 May 2003 14:44
> To: STOVES@LISTSERV.REPP.ORG
> Subject: Re: [STOVES] Energy in V.S. out.....
>
>
> Lead acid batteries produce no power at all, they only store power, so
it's not a like comparison. It is true, however, that batteries are not very
efficient energy storage medium, and not just the lead/acid variety, which
is why net metering has caught on so well.
>
>
>
> On Wed, May 28, 2003 at 03:07:06PM +0200, Carl Carley (EMP) wrote:
> > I've heard the same about lead acid batteries, is this true anyone?
> >
> > carl
> >
> > -----Original Message-----
> > From: Ron Larson [mailto:ronallarson@QWEST.NET]
> > Sent: 28 May 2003 13:22
> > To: STOVES@LISTSERV.REPP.ORG
> > Subject: Re: [STOVES] Energy in V.S. out.....
> >
> >
> > Hi Elsen:
> >
> > You asked:
> >
> > >I heard a curious fact a while ago, but I have not yet
> > >been able to establish the truth of it. 'Solar electric panels NEVER
> > >in their lifetime produce the amount of energy that it takes to
> > >manufacture them.'
> > >
> > >Can this be true?
> > >
> > >elk
> >
> >
> > See: http://www.nrel.gov/ncpv/pdfs/24596.pdf
> >
> > I used to work with this US national group and believe this
> > sort of rebuttal information (Energy payback time of 1 to 4 years)
> > only appears for public release when thoroughly reviewed. I have seen
> > even lower numbers - that may be more recent. I am pretty sure that
> > the number goes down more when talking about concentrating PV. Wind
> > system paybacks are cited in terms of months.
> >
> > If you or anyone can give the exact location where false
> > information like you cite exists, I'd like to hear about it.
> >
> > Ron
>
> --
> Harmon Seaver
> CyberShamanix
> http://www.cybershamanix.com

--
Harmon Seaver
CyberShamanix
http://www.cybershamanix.com

From andrew.heggie at DTN.NTL.COM Wed May 28 18:17:37 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:24 2004
Subject: Energy in V.S. out.....
In-Reply-To: <000601c3250f$ef8df160$3341083e@dell>
Message-ID: <WED.28.MAY.2003.231737.0100.>

On Wed, 28 May 2003 11:57:33 +0300, elk wrote:

I'm a little late to the fray but I don't believe this is true of
modern solar cells. Remember that there are advances being made in the
technology all the time, did you realise diamond could be doped as a
semiconductor? There has also recently been an announcement of a cell
with a record 18.3% of incident light converted to energy, I am told
the electron energy levels of a diamond semiconductor make higher
conversion possible.

Now remember there are lies, damn lies and statistics: it appears to
be a simple statistical fact, due to the exponential growth of
deployment of solar cells, that the total energy used in manufacture
has not yet been paid back in electricity generated. What must also be
taken into account is exergy or the "quality" of the energy. Electric
power is a very high quality, such that we are prepared to "spend" one
unit of energy to receive 1/3 of a unit of electricity.

I am unsure how much pv manufacture is a spin off of other
semiconductor market growth, I believe the cost of silicon chip has
been reducing by 20% for each doubling of growth. Also the simcoa
silicon smelter in Oz was run on good ole charcoal.

Modern thermal generators will reach 50% conversion, but the capital
costs are such that the old methods still have life in them, and they
all seem to want to use natural gas.

In UK we are so committed to reducing CO2 that no existing generators
will consider replacing coal plant, in effect this commits HMG to a
decision on generation capacity in 2005 which will inevitably mean
nuke or power starvation, I wonder if US is the same. I am not anti
nuke, just deeply sceptical about man's ability to handle it long
term.

Now as to Gav's comments about accommodating non-scheduled electricity
supplies into the network, what a can of worms! I can see the
possibility of net thermal efficiency losses occurring at some plants,
we have already, allegedly, seen this happen in deregulating
electricity supplies, as base load plants attempt to chase peak
prices.

It seems likely that our use of electricity may well have to change to
accommodate unscheduled supplies.

It came as a big eye opener to me to be told that our little gas
turbine genset consumed 75% of it's thermal input just to keep it
spooled up, it's why I still like diesel's and storing energy by
hanging bits of hydrogen off carbon atoms.

I'd love to see an energy balance for lead acid batteries, even with
reasonable recycling, I did see a calculation some years back, that
the energy storage cost over a typical life of charge-discharge cycles
cost USD0.13/kWhr when the grid electricity cost USD0.05/kWhr.

Now as to Gav's contention that energy costs are similar to dollar
costs, perhaps this linkage indicates just how much the western
economies are dependant on (cheap) energy.

AJH

From elk at WANANCHI.COM Thu May 29 01:03:19 2003
From: elk at WANANCHI.COM (elk)
Date: Tue Aug 10 18:30:24 2004
Subject: Energy in V.S. out.....
Message-ID: <THU.29.MAY.2003.080319.0300.ELK@WANANCHI.COM>

Ronal;
You wrote:

> If you or anyone can give the exact location where false information like
> you cite exists, I'd like to hear about it.

That little gem of (enviro legend?) misinformation came from a friend of
mine who's just moved from England to New Zealand. I'm afraid he may be
spreading the contagion around the world!

Not to worry though- we should have neutralised this particular vector- I've
copied him on all the responses.

Thanks for the info everyone!

elk

--------------------------
Elsen L. Karstad
elk@wananchi.com
www.chardust.com
Nairobi Kenya

----- Original Message -----
From: "Ron Larson" <ronallarson@qwest.net>
To: "elk" <elk@WANANCHI.COM>; <STOVES@LISTSERV.REPP.ORG>
Sent: Wednesday, May 28, 2003 3:22 PM
Subject: RE: Energy in V.S. out.....

> Hi Elsen:
>
> You asked:
>
> >I heard a curious fact a while ago, but I have not yet
> >been able to establish the truth of it. 'Solar electric
> >panels NEVER in their lifetime produce the amount of
> >energy that it takes to manufacture them.'
> >
> >Can this be true?
> >
> >elk
>
>
> See: http://www.nrel.gov/ncpv/pdfs/24596.pdf
>
> I used to work with this US national group and believe this sort of
> rebuttal information (Energy payback time of 1 to 4 years) only appears
for
> public release when thoroughly reviewed. I have seen even lower numbers -
> that may be more recent. I am pretty sure that the number goes down more
> when talking about concentrating PV. Wind system paybacks are cited in
> terms of months.
>
> If you or anyone can give the exact location where false information like
> you cite exists, I'd like to hear about it.
>
> Ron
>
>

From yark at U.WASHINGTON.EDU Thu May 29 15:51:59 2003
From: yark at U.WASHINGTON.EDU (Tami Bond)
Date: Tue Aug 10 18:30:24 2004
Subject: Burning rubber
In-Reply-To: <agq8dvg2ubc50opjktniv70albg78ce4lq@4ax.com>
Message-ID: <THU.29.MAY.2003.125159.0700.YARK@U.WASHINGTON.EDU>

On Fri, 23 May 2003, Andrew Heggie wrote:

> I remember querying Tami about this, without reply.

Ooooh, I'm in trouble... (Sorry gang, I'm in the middle of moving, so I am
even less reliable than usual)

> My take on the matter is that IF it smokes then there are bound to be
> pollutnats, CO PICs as PM2.5 and others. If it does no smoke then the PM
> 2.5 etc may be gone but there could well be large amounts of CO, NOx
> sulphur particles, VOCs PAHs etc. So a clean burning device is within
> the set of smokefree devices.

Here is my take on the matter from my limited experience. Please correct,
etc as usual.

As general rules which have many exceptions:

1. CO and PM2.5 come out together during incomplete combustion of volatile
matter (the white smoke). At this time you get lots of PAH.
2. CO comes out by itself when there is little volatile matter for making
PM2.5 (eg charcoal).
3. PM2.5 comes out by itself (a) when it's soot from a hot flame (b)
incombustible material (ash).
4. If you have sulfur in the fuel then it's going to come out in the
emissions, usually as gas.
5. NOx comes from hot flame, long residence times at high temperature,
and nitrogen in the fuel.
6. Any of the above can mix immediately after the flame zone, and gases
can stick on the particles, especially if they feel like condensing when
they cool down.

As an opinion, and not an experiment (as Dean would say), it will be very
easy to make nasty PM2.5 from rubber. That's because you're starting with
a lot of volatile material and soot precursors (building blocks). You will
have to be quite careful to keep the exhaust hot and mixed, and burn the
stuff out (think incinerator), and then you will have to worry about NOx.
Another issue is trace metals-- I don't know what is in tires, but some
nasty ones are volatile when you burn them, and it's tough to get them out
of the exhaust. I am guessing that tires are not a domestic-energy
solution, but will be happy for someone to prove me wrong.

Tami

From adkarve at PN2.VSNL.NET.IN Thu May 29 22:03:57 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:24 2004
Subject: pollutants produced by cookstoves
Message-ID: <FRI.30.MAY.2003.073357.0530.ADKARVE@PN2.VSNL.NET.IN>

Dear Tami,
sometime ago you had asked me if there was any correlation between CO and
suspended particulate matter. I reproduce below a part of a popular article
which I have sent for publication to a periodical in India. The facts
mentioned in the following paragraph are valid only for the traditional and
improved "Indian chulha". They may be different in the case of other
categories of improved cookstoves.
Indoor air in rural households gets polluted mainly by emissions from
traditional cookstoves, operated in poorly ventilated kitchens. The fuel
used in these stoves consists of wood, agricultural waste and dung cakes. It
does not burn cleanly. While burning, it always releases large quantities
of volatile organic compounds, collectively termed as tar. The yellow colour
of the flames indicates that the volatiles do not burn completely. As the
flames rise, the unburnt volatiles cool and condense to form particles of
tar, which, together with unburnt particles of carbon, form the pollutant
fraction called suspended particulate matter (SPM). Carbon monoxide (CO) is
another pollutant that is often produced by burning biomass, but studies
conducted in 2002 by Appropriate Rural Technology Institute, Pune (India),
showed that CO was not a major pollutant in the case of biomass burning
cookstoves. The CO concentration was relatively high only during the first
10 to 15 minutes of lighting the stove. Once the fire got going strongly,
the CO level in the kitchen atmosphere came down, but that of SPM remained
high throughout the period of cooking and also for several hours afterwards.
Yours
A.D.Karve
>

From ronallarson at QWEST.NET Thu May 29 23:42:34 2003
From: ronallarson at QWEST.NET (Ron Larson)
Date: Tue Aug 10 18:30:24 2004
Subject: Stoves development research funding opportunity
Message-ID: <THU.29.MAY.2003.214234.0600.RONALLARSON@QWEST.NET>

Stovers:

1. This is to ask you to consider sending in a short letter of support
(and perhaps thanks to the Gates Foundation) for those of our members who
specialize in the medical and health side of stoves. I shall be doing so,
mentioning this list, but trying to use as much medical and scientific
language as I can muster. If the selection committee eventually agrees
that this is an important research topic, then we may also be able to submit
more "hands-on" proposals. It seems definitely premature to send in stove
improvement research ideas at this time.

2. The reason for this request is an announcement that you can download at

http://www.grandchallengesgh.com/grandchallenge.pdf

3. The gist of that 3-page pdf is that the Gates Foundation is looking for
health/science ideas to later advertise a list of fundable research topics.
The instructions for right now are listed near the end:

"Respondents are encouraged but not required to include answers to the
questions listed below, which are intended as a guide to help explain the
merit of a proposed Grand Challenge.

1. What is the significance of the health problem to be addressed?
2. What is the scientific rationale for proposing this challenge at this
time?
3. What are the scientific and technical advances that are anticipated if
the challenge is
successfully completed?
4. What is the likely impact of those advances on the development of new
means to control or
treat disease in the developing world?
5. What is the feasibility of implementing any resulting new measures
against disease in the
developing world?
6. Are there any other comments you wish to make about the proposed
challenge?"

4. They say: "In order to expedite this process, submission through the
Web site www.grandchallengesgh.org is preferred."

I don't know that anyone on our list can add to what is available at the
sites above - but anyone reading this should feel free to chime in and
especially to pass this opportunity to influence the future on to other
lists like ours.

Ron

From Gavin at AA3GENERGI.FORCE9.CO.UK Fri May 30 06:39:37 2003
From: Gavin at AA3GENERGI.FORCE9.CO.UK (Gavin Gulliver-Goodall)
Date: Tue Aug 10 18:30:24 2004
Subject: FW: [STOVES] Energy in V.S. out.....
In-Reply-To: <E3117AE4EC45D511BEC10002A55CB09C01A2BEA0@eukbant102.uk.eu.ericsson.se>
Message-ID: <FRI.30.MAY.2003.113937.0100.GAVIN@AA3GENERGI.FORCE9.CO.UK>

I have always thought so.- any large scale energy extraction/conversion
system must have long term effects on the earth as a whole, we are as they
say in THE MATRIX becoming parasites on the planet! No longer in symbiosis
with our environment.
gavin
I guess if we had really efficient solar electricity panels then covering a
large area of the earths surface then there would be localised climatic
changes.

The same applies to wind farms

From ronallarson at QWEST.NET Fri May 30 09:50:34 2003
From: ronallarson at QWEST.NET (Ron Larson)
Date: Tue Aug 10 18:30:24 2004
Subject: FW: [STOVES] Energy in V.S. out.....
In-Reply-To: <200305301113.h4UBDNo14759@ns1.repp.org>
Message-ID: <FRI.30.MAY.2003.075034.0600.RONALLARSON@QWEST.NET>

Gavin et al

Two responses.

Below you raise the point about micro-climate effects. I remember reading
many years ago that this could be controlled quite a bit (meaning I guess a
return to local norms) by the color on the back side of the panels or
mirrors that are in place. No way I could find that reference now - but the
local albedo effects can give lots of different results.
I also remember talk about having a "healthy" local effect in deserts,
where plants could be grown in the shady area behind or under the array -
and otherwise the environment was too inhospitable. Probably areas in the
world where shade for cattle could be considered a local economic help.
But for the PV industry, their answer would probably be that the right
place is the rooftop - where the incremental effect of PV over the original
is presumably pretty small.
The US also is said to be able to run its entire electricity sector with a
square PV array 100 miles on a side (10,000 sq km). This is a small
fraction of our total national desert area - although we will never of
course do it in this way.

Re wind: There is a sizeable local perturbation where - about 50% of the
energy can be captured and sent elsewhere - but this is over a small portion
of the available cross-sectional area - and the effect is barely seen (I
think) at ground level. I have not heard ever of a concern that an energy
removal effect would be considered a strong negative. In general the best
wind sites have low economic value as they are considered too windy.

You earlier described a need for about a 50% spinning reserve requirement.
This also was the claim of our local utility in a Commission fight in which
I was involved. In a later full study at a sister utility, I think the
number came out at around 6% (maybe 4%). Our local utility supply goes up
and down by a factor of 2 every day in demand - so only moderate attention
by them to the weather can make an added wind farm a pretty insignificant
cost contributor. I strongly recommend not using the number 50% as the
spinning reserve requirement - I cannot believe it is a correct number
anywhere in the world. I have a recent paper if anyone wants - showing the
value of large geographic spatial diversity on this number. That is, the
spinning reseve requirement goes down as more wind farms are installed.

>-----Original Message-----
>From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On
>Behalf Of Gavin Gulliver-Goodall
>Sent: Friday, May 30, 2003 4:40 AM
>To: STOVES@LISTSERV.REPP.ORG
>Subject: Re: FW: [STOVES] Energy in V.S. out.....
>
>
>---------------------- Information from the mail header
>-----------------------
>Sender: The Stoves Discussion List <STOVES@LISTSERV.REPP.ORG>
>Poster: Gavin Gulliver-Goodall <Gavin@AA3GENERGI.FORCE9.CO.UK>
>Subject: Re: FW: [STOVES] Energy in V.S. out.....
>-------------------------------------------------------------------
>------------
>
>I have always thought so.- any large scale energy extraction/conversion
>system must have long term effects on the earth as a whole, we are as they
>say in THE MATRIX becoming parasites on the planet! No longer in symbiosis
>with our environment.
>gavin
>I guess if we had really efficient solar electricity panels then covering a
>large area of the earths surface then there would be localised climatic
>changes.
>
>The same applies to wind farms
>
>

From crispin at NEWDAWN.SZ Sat May 31 12:21:18 2003
From: crispin at NEWDAWN.SZ (Newdawn (Africa Online))
Date: Tue Aug 10 18:30:24 2004
Subject: Energy in V.S. out.....
Message-ID: <SAT.31.MAY.2003.182118.0200.CRISPIN@NEWDAWN.SZ>

Dear Ron

We should remember that when one talks of large socal arrays the Sahara is
often mentioned as an ideal place for large scale implementation. The
Sahara is, in many places, clouded with high dust for months and although
there is bright sunshine, the sun itself can't be seen. It is not clear
where to point an array and focusing systems are useless for a fair portion
of the time.

The Western US deserts seem to be far clearer, true?

As for the energy content of a solar PV array, I suspect that the figures
for 'energy content' don't reflect the gasoline the plant operator used to
make the epoxy that glues the array together and so on. The "real" energy
content of a panel would require taht one simulate a whole city with
education and retirement homes manufacturing only panels so one ca see what
energy investment is made in a whole community in order to produce panels.
I really doubt that the power generated by the panel will come close to the
total energy portion expended by a society in creating the panel.

A solar panel is really a battery that is activated by direct sunlight.

There are highly positive energy returns on hydro systems and probably solar
steam engines which have a far higher % energy capture figure.

Regards
Crispin in need of a little solar heat at this time of year myself

BioEnergy Lists: Improved Biomass Cooking Stoves

May 2003 Biomass Cooking Stoves Archive