[Stoves] A heat-resistant insulation mix
Xavier Brandao
xvr.brandao at gmail.com
Sat Aug 13 04:43:40 CDT 2011
Roger said :"My preference would be the kao wool insulating blanket which
can be ordered from stove suppliers readily here in the states"
I am situated in South Benin. I was talking to a refrigerating engineer in
Cotonou (he repairs and sells ovens too), and he was boasting rock wool.
Very easy to handle, great insulation. But it is very expensive, 5000 CFA F
per square meter if I recall well, about 7,6 euro, and in very small
quantity. Some people don't know its value and just dispose of it, but it
won't be enough for all our stoves.
Clay, laterite, sawdust, sand also, are cheap and traditional material that
can easily be found. We will be using something cheap.
To Kobus,
Thanks for the link, I have the paper. Peter Scott also gave me a few
advices when we built our first institutional stove. I also have Crispin's
paper. The papers (very well) explain how to make insulative and
non-insulative ceramic and fire bricks. But in every case, tell me if I am
wrong, a kiln is needed.
This is our problem.
The producers could make some bricks for us, but once in a while. Production
capacities are small, demand is high. One of them has a big factory, and
makes clay bricks for buildings, some of them insulative. If we wanted our
own bricks, specially shaped for the stove, we would need to make a special
mold, and to order more than 8000 bricks. We can't do that at the moment.
Cooking bricks with a wood-fire does not work, at least it didn't work for
us.
We see now 3 solutions:
- continue with the expensive inox combustion chamber and 5 cm insulative
material. We need a mix that will resist heat. Something like the
vitrificating mix Larry was talking about.
- another solution was proposed by a welder we work with. He thinks it would
be possible to make a mix of 70% laterite, 30% cement between a 1mm sheet
metal combustion chamber and the 1,5 mm sheet metal outside body of the
stove. The mix will become very hard according to him, even without being
submitted to a high heat. The 1mm sheet metal would burn and disintegrate
over time when the stove is operating, leaving only the mix. So this sheet
metal would act as a "burnable" mold. Or it could be used as a simple mold,
and be removed when the mix is hard.
- use standard size clay bricks and cut them at the size of the stove. This
is what we are trying at the moment. This is highly experimental. They are
cut in 2 pieces. The whole combustion chamber is made of these half-bricks.
We are not using insulative bricks, the major weak spot should be solidity.
We need the most resistant bricks.
We completed the combustion chamber today, it looks nice, even if it is not
very regular. It was cut with an angle-grinder with a disk coated with
diamond. Cutting bricks makes a lot of smoke. If this solution is workable,
a machine to cut the bricks would be nice.
Pictures of the experiment here:
- http://imageshack.us/photo/my-images/844/sam1233.jpg/
- http://imageshack.us/photo/my-images/51/sam1277r.jpg/
- http://imageshack.us/photo/my-images/98/sam1278l.jpg/
- http://imageshack.us/photo/my-images/593/sam1280z.jpg/
- http://imageshack.us/photo/my-images/836/sam1281.jpg/
- http://imageshack.us/photo/my-images/833/sam1282d.jpg/
I have the feeling I should rather use clay than laterite. Laterite can
become rock-hard and is insulative, but I was told it is less insulative
than clay. I couldn't find any Welders use laterite for their forges, like
this one:
- http://imageshack.us/photo/my-images/854/sam1254r.jpg/
We still need to fill our now empty stoves with a mix. What do you stovers
think of an insulative mix composed or 50% laterite in powder or 50% clay in
powder? Would it be too dense? Does it always need a burnable organic
material?
Cheers,
Xavier
-----Message d'origine-----
De : stoves-bounces at lists.bioenergylists.org
[mailto:stoves-bounces at lists.bioenergylists.org] De la part de
stoves-request at lists.bioenergylists.org
Envoyé : mercredi 10 août 2011 16:31
À : stoves at lists.bioenergylists.org
Objet : Stoves Digest, Vol 12, Issue 21
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Today's Topics:
1. New type of sawdust stove in Gambia (Crispin Pemberton-Pigott)
2. Re: New type of sawdust stove in Gambia (Rok Oblak)
3. Re: A heat-resistant insulation mix (larry winiarski)
4. Re: New type of sawdust stove in Gambia (Crispin Pemberton-Pigott)
5. Re: A heat-resistant insulation mix (Crispin Pemberton-Pigott)
6. Re: A heat-resistant insulation mix (Crispin Pemberton-Pigott)
7. Re: A heat-resistant insulation mix (Xavier Brandao)
8. Re: Charcoal in Gambia (rongretlarson at comcast.net)
9. Re: A heat-resistant insulation mix (Fireside Hearth)
----------------------------------------------------------------------
Message: 1
Date: Wed, 10 Aug 2011 01:21:59 -0400
From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com>
To: "Stoves" <stoves at lists.bioenergylists.org>
Subject: [Stoves] New type of sawdust stove in Gambia
Message-ID: <139c01cc571d$6ed39590$4c7ac0b0$@gmail.com>
Content-Type: text/plain; charset="us-ascii"
Dear Friends
Cecil in Banjul has reported (and I hope has pictures) of a sawdust stove
that uses a novel method of keeping the flame running throughout the burn.
Sawdust stoves, like some gasifiers, are notorious for making a lot of smoke
if anything goes wrong.
The cylindrical stove is a 22 cm diameter can with a height of about 25 cm.
There is a side hole that is made by cutting a D-shaped flap. The curved cut
is started about 4 cm from the bottom, curves down and then up again to make
an opening about 8 or 10 cm wide and 4 cm from the bottom. This allows
access to the central hole which is produced by an inverted Coke bottle.
After pounding in the sawdust, the opening provided by the side hole is
scooped out using a small stick until the central vertical hole is reached.
The sawdust is lit a the bottom using (in this case) a piece of Styrofoam.
Small sticks are kept burning in the side hole throughout the cooking
period. This is the unusual part.
This very small side-fed fire continuously provides a flame to ignite the
smoke that evolves from the sawdust.
Later on they put in one larger stick, late in the burn if they want to push
the power up.
A full charge will burn for about several hours if allowed to smoulder. A
typical cooking session is about 2 hours. They use huge aluminum pots. It
boiled about 8 litres of tea in 30 minutes later on in the burn.
The use of the small sticks as flame providers ensures there is very little
smoke at all during the burn. Quite amazing, apparently.
I will send pictures once they arrive.
He also reports that there is not a single pot in the Gambia that has no lid
on it, and people look at you as if you are daft to ask whether or not they
use. Good for them. We are daft to ask such a question.
Regards
Crispin
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Message: 2
Date: Tue, 9 Aug 2011 23:08:12 -0700
From: Rok Oblak <rok.stoves at gmail.com>
To: Discussion of biomass cooking stoves
<stoves at lists.bioenergylists.org>
Subject: Re: [Stoves] New type of sawdust stove in Gambia
Message-ID:
<CAB-CVjXL46ViwxQ6RmusmoRVvxpWXxm1QtM-iPGy3jEBkDzrAQ at mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"
Hi Crispin, very interesting application for briquettes as well
I was using a similar technique, where the sticks were inserted from
underneath of the horizontally laid briquettes with the vertical hole in the
middle (same thing as a sawdust stove). It kept the flames going all the
time.
http://holeyroket.files.wordpress.com/2009/07/img_62071.jpg
http://holeyroket.files.wordpress.com/2009/07/img_62021.jpg
In that case in Malawi this was used for 2 reasons; one being the poor
quality briquettes that weren't burning well and the other that with more or
less sticks pushed in, you were able to regulate the fire output as with the
3-stones fire that people were already used to cook with.. Check these
photos for a reference. Very little help was needed, but it was quite
essential to prevent the smoke - same as you're saying
I also found myself pushing a stick right through a briquette sometimes with
the new side-fed briquette stove, its good for keeping up the fire with no
smoke at the startup.. you think it could be beneficial making bigger holes
higher up the combustion chamber or it would cool the air in the combustion
chamber too much maybe when the sticks would not be inserted? Worth trying
though
Cheers
Rok
On Tue, Aug 9, 2011 at 10:21 PM, Crispin Pemberton-Pigott <
crispinpigott at gmail.com> wrote:
> Dear Friends****
>
> ** **
>
> Cecil in Banjul has reported (and I hope has pictures) of a sawdust stove
> that uses a novel method of keeping the flame running throughout the burn.
> Sawdust stoves, like some gasifiers, are notorious for making a lot of
smoke
> if anything goes wrong.****
>
> ** **
>
> The cylindrical stove is a 22 cm diameter can with a height of about 25
cm.
> There is a side hole that is made by cutting a D-shaped flap. The curved
cut
> is started about 4 cm from the bottom, curves down and then up again to
make
> an opening about 8 or 10 cm wide and 4 cm from the bottom. This allows
> access to the central hole which is produced by an inverted Coke bottle.**
> **
>
> ** **
>
> After pounding in the sawdust, the opening provided by the side hole is
> scooped out using a small stick until the central vertical hole is
reached.
> The sawdust is lit a the bottom using (in this case) a piece of Styrofoam.
> Small sticks are kept burning in the side hole throughout the cooking
> period. This is the unusual part.****
>
> ** **
>
> This very small side-fed fire continuously provides a flame to ignite the
> smoke that evolves from the sawdust.****
>
> ** **
>
> Later on they put in one larger stick, late in the burn if they want to
> push the power up.****
>
> ** **
>
> A full charge will burn for about several hours if allowed to smoulder. A
> typical cooking session is about 2 hours. They use huge aluminum pots. It
> boiled about 8 litres of tea in 30 minutes later on in the burn.****
>
> ** **
>
> The use of the small sticks as flame providers ensures there is very
little
> smoke at all during the burn. Quite amazing, apparently.****
>
> ** **
>
> I will send pictures once they arrive.****
>
> ** **
>
> He also reports that there is not a single pot in the Gambia that has no
> lid on it, and people look at you as if you are daft to ask whether or not
> they use. Good for them. We *are* daft to ask such a question.****
>
> ** **
>
> Regards****
>
> Crispin****
>
> ** **
>
> _______________________________________________
> Stoves mailing list
>
> to Send a Message to the list, use the email address
> stoves at lists.bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
>
>
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists
.org
>
> for more Biomass Cooking Stoves, News and Information see our web site:
> http://www.bioenergylists.org/
>
>
>
--
*Rok Oblak, MAA Design*
+1 604 710 1615
rok.stoves at gmail.com
www.holeyroket.com
1605-1255 Pendrell Street
Vancouver, BC V6E 1E7
Canada <http://www.rokstoves.com/>
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Message: 3
Date: Wed, 10 Aug 2011 00:09:26 -0700
From: "larry winiarski" <larryw at gotsky.com>
To: "Discussion of biomass cooking stoves"
<stoves at lists.bioenergylists.org>
Cc: Jon Anderson <jonnygms at gmail.com>, Brian Sparks
<bh.sparks at yahoo.com>
Subject: Re: [Stoves] A heat-resistant insulation mix
Message-ID: <ED618E093B5B4728A4B3FDC063FF09CC at larryspc>
Content-Type: text/plain; charset="iso-8859-1"
Thanks Frans
I did not That!
sodium silicate is called water glass But I read recently potassium silicate
is also called water glass. I also heard that Potash made from human Urine
(chamber lye) contains po tassium nitrate, a key component of gunpowder.
During the american civil war the South was short of potasium so the
confedera te army in Atlanta Georgia requested all the women to save their
"chamber Lye" and the army would collect it to-- soak and then burn straw to
make potassium nitrate. (Nitre)??
Their is a funny song about this. Google to find "mudcat cafe "and search
for a song called "chamber lye"
Larry
----- Original Message -----
From: Frans Peeters
To: 'Discussion of biomass cooking stoves'
Sent: Tuesday, August 09, 2011 3:33 PM
Subject: Re: [Stoves] A heat-resistant insulation mix
Larry
Potasium salt !
Potasium chloride salt cement is used with quartsite to make mais mill
stones .
Strong it must be .
Regards
Frans
----------------------------------------------------------------------------
--
Van: stoves-bounces at lists.bioenergylists.org
[mailto:stoves-bounces at lists.bioenergylists.org] Namens larry winiarski
Verzonden: dinsdag 9 augustus 2011 8:04
Aan: Discussion of biomass cooking stoves
CC: Jon Anderson
Onderwerp: Re: [Stoves] A heat-resistant insulation mix
Xavier
Jon anderson and wife Flip been making making many self firing clay
/organic mixes --adding some form of potassium salts to a bout 50-50
volume mix of clay organic. they have got potash water from leaching wood
ashes. Horse dung with urine also seems to work well. If you increase the
draft temporarily with a chimney extension and fire hard for several hours.
the stove becomes a miniture kiln and vitrifys the inner linning to brick.
The potassium appears to act as a flux to lower the temperature at which the
clay will vitrify. I think others on the stove list (Crispin?) have made
similar suggestions It looks very promising Check what Jon and flip have
posted
God Bless
Larry
----------------------------------------------------------------------------
--
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Message: 4
Date: Wed, 10 Aug 2011 08:27:41 -0400
From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com>
To: "'Discussion of biomass cooking stoves'"
<stoves at lists.bioenergylists.org>
Subject: Re: [Stoves] New type of sawdust stove in Gambia
Message-ID: <13d401cc5758$e6e68f70$b4b3ae50$@gmail.com>
Content-Type: text/plain; charset="us-ascii"
Dear Rok
This is really worth thinking about - it is a compound fuel stove, using a
small amount of wood to regulate the power and control the smoke. Very
interesting. And most important as you note, makes a poor fuel into a good
one for a very low investment in management.
Will try to write more later addressing your questions.
Regards
Crispin
From: stoves-bounces at lists.bioenergylists.org
[mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of Rok Oblak
Sent: 10 August 2011 02:08
To: Discussion of biomass cooking stoves
Subject: Re: [Stoves] New type of sawdust stove in Gambia
Hi Crispin, very interesting application for briquettes as well
I was using a similar technique, where the sticks were inserted from
underneath of the horizontally laid briquettes with the vertical hole in the
middle (same thing as a sawdust stove). It kept the flames going all the
time.
http://holeyroket.files.wordpress.com/2009/07/img_62071.jpg
http://holeyroket.files.wordpress.com/2009/07/img_62021.jpg
In that case in Malawi this was used for 2 reasons; one being the poor
quality briquettes that weren't burning well and the other that with more or
less sticks pushed in, you were able to regulate the fire output as with the
3-stones fire that people were already used to cook with.. Check these
photos for a reference. Very little help was needed, but it was quite
essential to prevent the smoke - same as you're saying
I also found myself pushing a stick right through a briquette sometimes with
the new side-fed briquette stove, its good for keeping up the fire with no
smoke at the startup.. you think it could be beneficial making bigger holes
higher up the combustion chamber or it would cool the air in the combustion
chamber too much maybe when the sticks would not be inserted? Worth trying
though
Cheers
Rok
On Tue, Aug 9, 2011 at 10:21 PM, Crispin Pemberton-Pigott
<crispinpigott at gmail.com> wrote:
Dear Friends
Cecil in Banjul has reported (and I hope has pictures) of a sawdust stove
that uses a novel method of keeping the flame running throughout the burn.
Sawdust stoves, like some gasifiers, are notorious for making a lot of smoke
if anything goes wrong.
The cylindrical stove is a 22 cm diameter can with a height of about 25 cm.
There is a side hole that is made by cutting a D-shaped flap. The curved cut
is started about 4 cm from the bottom, curves down and then up again to make
an opening about 8 or 10 cm wide and 4 cm from the bottom. This allows
access to the central hole which is produced by an inverted Coke bottle.
After pounding in the sawdust, the opening provided by the side hole is
scooped out using a small stick until the central vertical hole is reached.
The sawdust is lit a the bottom using (in this case) a piece of Styrofoam.
Small sticks are kept burning in the side hole throughout the cooking
period. This is the unusual part.
This very small side-fed fire continuously provides a flame to ignite the
smoke that evolves from the sawdust.
Later on they put in one larger stick, late in the burn if they want to push
the power up.
A full charge will burn for about several hours if allowed to smoulder. A
typical cooking session is about 2 hours. They use huge aluminum pots. It
boiled about 8 litres of tea in 30 minutes later on in the burn.
The use of the small sticks as flame providers ensures there is very little
smoke at all during the burn. Quite amazing, apparently.
I will send pictures once they arrive.
He also reports that there is not a single pot in the Gambia that has no lid
on it, and people look at you as if you are daft to ask whether or not they
use. Good for them. We are daft to ask such a question.
Regards
Crispin
_______________________________________________
Stoves mailing list
to Send a Message to the list, use the email address
stoves at lists.bioenergylists.org
to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists
.org
for more Biomass Cooking Stoves, News and Information see our web site:
http://www.bioenergylists.org/
--
Rok Oblak, MAA Design
+1 604 710 1615
rok.stoves at gmail.com
www.holeyroket.com <http://www.holeyroket.com/>
1605-1255 Pendrell Street
Vancouver, BC V6E 1E7
Canada
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Message: 5
Date: Wed, 10 Aug 2011 09:49:55 -0400
From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com>
To: "'Discussion of biomass cooking stoves'"
<stoves at lists.bioenergylists.org>
Subject: Re: [Stoves] A heat-resistant insulation mix
Message-ID: <13e501cc5764$64ee59b0$2ecb0d10$@gmail.com>
Content-Type: text/plain; charset="us-ascii"
Dear Xavier
The best product I have seen used with ordinary clay is sodium silicate.
There are two forms of it available, one is a liquid. Use that one if you
can get it.
It makes the clay very hard and resistant to thermal shock.
Regards
Crispin
+++++
Larry
Potasium salt !
Potasium chloride salt cement is used with quartsite to make mais mill
stones .
Strong it must be .
Regards
Frans
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Message: 6
Date: Wed, 10 Aug 2011 10:02:10 -0400
From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com>
To: "'Discussion of biomass cooking stoves'"
<stoves at lists.bioenergylists.org>
Subject: Re: [Stoves] A heat-resistant insulation mix
Message-ID: <13f801cc5766$19df7f60$4d9e7e20$@gmail.com>
Content-Type: text/plain; charset="utf-8"
Sodium silicate
>From Wikipedia, the free encyclopedia
Sodium metasilicate
Other names
Liquid glass
Waterglass
Properties
Molecular formula
Na2O3Si
Molar mass
122.06 g mol?1
Appearance
White, opaque crystals
Density
2.4 g cm-3
Melting point
1088 ?C, 1361 K, 1990 ?F
Sodium silicate is the common name for a compound sodium metasilicate,
Na2SiO3, also known as water glass or liquid glass. It is available in
aqueous solution and in solid form and is used in cements, passive fire
protection, refractories, textile and lumber processing, and automobiles.
Sodium carbonate and silicon dioxide react when molten to form sodium
silicate and carbon dioxide:[1]
Na2CO3 + SiO2 ? Na2SiO3 + CO2
Anhydrous sodium silicate contains a chain polymeric anion composed of
corner shared {SiO4} tetrahedral, and not a discrete SiO32? ion.[1] In
addition to the anhydrous form, there are hydrates with the formula
Na2SiO3?nH2O (where n = 5, 6, 8, 9) which contain the discrete,
approximately tetrahedral anion SiO2(OH)22? with water of hydration. For
example, the commercially available sodium silicate pentahydrate
Na2SiO3?5H2O is formulated as Na2SiO2(OH)2?4H2O and the nonahydrate
Na2SiO3?9H2O is formulated as Na2SiO2(OH)2?8H2O.[2]
In industry, the different grades of sodium silicate are characterized by
their SiO2:Na2O ratio, which can vary between 2:1 and 3.75:1.[3] Grades with
this ratio below 2.85:1 are termed 'alkaline'. Those with a higher SiO2:Na2O
ratio are described as 'neutral'.
Regards
Crispin
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Message: 7
Date: Wed, 10 Aug 2011 16:05:44 +0100
From: "Xavier Brandao" <xvr.brandao at gmail.com>
To: <stoves at lists.bioenergylists.org>
Subject: Re: [Stoves] A heat-resistant insulation mix
Message-ID: <4e429e67.0f3edf0a.62ed.3ca8 at mx.google.com>
Content-Type: text/plain; charset="iso-8859-1"
Hey everyone,
Roger said: "is your space between the walls sealed enough that you might be
able to use plain old sand? Is sand available to you plentifully enough?"
I'm afraid it is not fully sealed, we try to have a plain and nice-looking
welding, but there are often a few holes left. It is not totally hermetic.
Sand is available, even if the government has forbidden sandpits on the
coast, it was causing coastal erosion.
Is sand that good an insulation? I always heard it was too dense ... I think
it would make the stove heavy also. What about its expansion when submitted
to a high heat? Crispin says in his paper Development of a low thermal
expansion ceramic body: ?One of the most important changes that occurs in
any clay happens at 573? when free Silica (ordinary Quartz sand) changes
from an Alpha to a Beta crystal structure and increases in volume by about
1% over a very small temperature range.)?
I don?t know how hot a big institutional stove in operation is.
To Crispin: the 3D printing technology is amazing. One day, we?ll all sit
and sip cold drinks while watching these machines work for us.
To Larry: very interesting! ?Self-firing?, ?vitrify?, you are putting words
on a process I was only guessing. I can assure you that when we first put
the clay-sawdust mix in the institutional stove, we didn?t know what we were
doing! On a website for potters, several types of clay are for sale:
?True ceramics are fired at over 2000 degrees F, which turns the clay into a
glass-like material.?
?This is a self hardening clay - no need to cure in an oven or kiln.?
?this clay will harden after baking for one hour in your kitchen oven at 350
degrees F?
There?s a website explaining how to fire the clay-horse manure mix:
http://www.claytonbailey.com/internalcombus.htm
It is self-firing, but seems better in a ?well insulated and tightly packed
kiln chamber? at 500 degrees farenheit (260 degree celcius if I am correct).
Why horse? Not so many horses in Africa ?
Camel or donkeys aren?t so many either, perhaps we?ll try with cow or sheep
dung. I didn?t find info about the mix on bioenergylist, I contacted Jon
Anderson by email.
Many thanks,
Xavier
------------------------------
Message: 8
Date: Wed, 10 Aug 2011 15:31:10 +0000 (UTC)
From: rongretlarson at comcast.net
To: Discussion of biomass cooking stoves
<stoves at lists.bioenergylists.org>, Crispin Pemberton-Pigott
<crispinpigott at gmail.com>
Cc: Paul Olivier <paul.olivier at esrla.com>, biochar-policy
<biochar-policy at yahoogroups.com>, Danny Growald
<dgrowald at gmail.com>
Subject: Re: [Stoves] Charcoal in Gambia
Message-ID:
<1445729455.437294.1312990270446.JavaMail.root at sz0133a.emeryville.ca.mail.co
mcast.net>
Content-Type: text/plain; charset="utf-8"
Crispin, cc list:
Can you ask Cecil to get a few more price numbers - including loose rice
husks, peanut shells, wood sticks and chips, pellets. Anything that can be
readily pyrolyzed and is relatively low cost.
The Gambian prices of about 15 to 20 c/kg ($150-$200/ tonne) are certainly
pretty low. However, I hope we can all agree that is not the only thing we
should be discussing. What is the social cost of that char? My guess is that
it is at least double or maybe triple that number - even before you start
looking at the climate implications. Was the input wood for the char grown
by the char maker? Not usually in these cases.
I found (by googling) dozens of news items on the illegal production of
charcoal outlawed in Gambia. (Don't google for 'legal" and "charcoal") The
same is true in Kenya - which we have also been discussing. Does anyone know
of any African country where char production is considered a plus for the
economy? Living in Sudan has convinced me that charcoal making is the number
one reason for that country's disappointing history.
I found this at this Gambian planning site <
http://www.npc.gov.gm/sectors/energy >
" One of the key determinants of socio-economic development is the
availability of reliable supply of
affordable sources of energy that impacts directly on poverty. Past
experiences suggest a close
relationship between energy use and poverty reduction through sustainable
economic growth. A
review of the Gambia?s energy sector reveals that the energy resource base
of the country is limited
and the energy supply unreliable and unsustainable. The major source of
energy for the whole
country, according to the Energy Data (1990 ? 2004), is fuel wood, which is
extracted from the
country?s forest resources, followed by petroleum products, electricity and
renewable energy. Total
energy consumed in 2004 was 467 thousand Ton Oil Equivalent (TOE).
Fuel wood consumption account for 374.89 thousand TOE, representing about
82% of all energy
consumed in the country. The over-reliance of the city and major urban
centres on fuel wood
(firewood and charcoal) is destroying the country?s forest resources and
natural vegetation cover at
an alarming rate, causing general environmental degradation. While these
forest resources are
fetched from the rural areas, the participation of the rural people in the
business of fuel wood are
limited (according to Lahmeyer International Reports) and therefore
impacting negatively on the
poor. In addition, the use of fuel wood has serious negative health
implication on women. The
depletion of the forest cover leading to desertification, would impact
negatively on food production,
which could lead to increased hunger and poverty "
If the peanut log is 6 Dalasi, your comment below doesn't make sense to me
in terms of balancing from the perspective of the user. Your suggested
markup by 50% is sort of like saying that the right purchase price of
ethanol (with lower fuel content per gallon) is one that is higher per
gallon than the price of petrol - doesn't work that way in Colorado. I would
be surprised to hear that many of these logs are being sold. I'd like to
hear from Richard Stanley or other ag residue briquette makers on how his
briquettes are priced in comparison with char..
I'll bet the user of a charcoal-making stove can get the cost of cooking a
meal down to zero by selling the produced char (of course for putting in the
ground) for enough to pay for the (presumed to be very low) cost of input
biomass. Of course the economics in favor of a char-making stove is a
no-brainer if the input fuel is free, nearby and already being burned as a
waste. It also works if soil productivity is raised sufficiently - which
seems to be the word coming out of Africa (a doubling?)
Ron
----- Original Message -----
From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com>
To: "Stoves" <stoves at lists.bioenergylists.org>
Sent: Tuesday, August 9, 2011 10:15:54 PM
Subject: [Stoves] Charcoal in Gambia
Dear Charcoal Price Observers
Cecil Cook in the Gambia reports that charcoal is 4 to 5 Dalasi per kg in
Banjul (about 27 MJ.kg)
Peanut shell extruded logs are 6 Dalasi per kg retail to do better than
break even (about 19 MJ/kg).
There are 27 Dalasi per US$.
Regards
Crispin
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Message: 9
Date: Wed, 10 Aug 2011 08:35:00 -0700
From: Fireside Hearth <firesidehearthvashon at hotmail.com>
To: <stoves at lists.bioenergylists.org>
Subject: Re: [Stoves] A heat-resistant insulation mix
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> Hey everyone,
>
> Roger said: "is your space between the walls sealed enough that you might
be
> able to use plain old sand? Is sand available to you plentifully enough?"
> I'm afraid it is not fully sealed, we try to have a plain and nice-looking
> welding, but there are often a few holes left. It is not totally hermetic.
> Sand is available, even if the government has forbidden sandpits on the
> coast, it was causing coastal erosion.
> Is sand that good an insulation? I always heard it was too dense ... I
think
Hello Xavier....
I don't know where you are, or what is available to you....nor your
budget. My preference would be the kao wool insulating blanket which can be
ordered from stove suppliers readily here in the states......and to us seems
pretty inexpensive. The 1" thick stuff is rated for 2100.deg f. It is light
weight and a ceramic fiber type wool if you will. It is a key component in
my stove for the purpose of reflecting heat back at the inner liner. If your
stove is not portable and you could trap the sand between the walls of your
stove, this might just be enough insulating to do what you need, and
temperature should not do to it what it did to the clay/sawdust mix. I am
sure there are more ways than this, I was just trying to think up something
that might be plentiful, free, and easy.
R
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