November 1998 Gasification Archive

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From heat-win at mcmail.com Sun Nov 1 01:35:35 1998
From: heat-win at mcmail.com (T J Stubbing)
Date: Tue Aug 31 21:36:08 2004
Subject: Icy Ball
Message-ID: <363C0924.29354D58@mcmail.com>

Dear Stovers,

Regarding the messages on this from Elsen Karstad and others, before
electricity came to up-country Nigeria where I lived in the 1950's we
all had commercially available refrigerators with a kerosene flame below
an open tube which I assume passed through an ammonia filled,
automatically pressurising and de-pressurising heat pump extracting heat
from the products and making plenty of ice cubes for our 'sun-downers'!

Electrolux in Sweden and other manufacturers made these units which were
trouble-free in operation, and are no doubt still making them for areas
without electricity. They could presumbaly burn gasification gases
instead of kerosene and be made larger to provide local cold stores.

Regards,

Thomas J Stubbing

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From elk at net2000ke.com Mon Nov 2 00:05:59 1998
From: elk at net2000ke.com (Elsen Karstad)
Date: Tue Aug 31 21:36:09 2004
Subject: Ice Production
Message-ID: <199811020518.IAA13498@net2000ke.com>

With reference to our discussion on the possibilities of using the energy from flared volatiles produced during the production of charcoal, T.J. Stubbing accurately points out that there is well developed refrigeration technology available in the form of both Kerosene and LPG gas powered refrigeration. Indeed- and I own a LPG refrigerator- a full sized one at my trout farm which is off the grid. This refrigerator works as well as any electric unit despite being 25 years old and having no handle- just a brick- to keep the door shut. Gas consumption is in the order of 13 kg LPG very 6 weeks. And it does produce enough ice for our sundowners. Just remember to decarbonise it every 2 weeks.......I was intrigued by the icy ball as a vehicle for producing ice from waste heat because it appears to be the simplest form of refrigeration to below ice-making temperatures. I don't like the term 'pressure-vessel' used in the description (Dean Still ?)... could be a bomb in the massive heat of flared volatiles.Coke has distributed hundreds of kerosene powered chest coolers around Kenya- they are cold enough to produce a skin of ice around the inside walls. I'll look into aquiring the innards from one of these. In addition to the possibility of commercial scale ice making by using flared volatiles, how about a charcoal-making stove that has the ability to power a refrigerator too?! The charcoal can be left in the stove with very little primary air input and allowed to combust slowly after cooking is complete. This could drive the refrigerator for an additional hour or two....Another distraction!elk~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Elsen L. Karstad , P.O. Box 24371 Nairobi Kenyaelk@net2000ke.com tel/fax (+ 254 2) 884437

From dstill at epud.org Mon Nov 2 17:22:42 1998
From: dstill at epud.org (Dean Still)
Date: Tue Aug 31 21:36:09 2004
Subject: Icy Ball
Message-ID: <199811022234.OAA03911@seahorse.epud.net>

Back to the Icy-Ball...Larry and I sort of switched attention from the
Icy-Ball, originally designed by Crowsley and mass produced in the U.S. in
the 30's, to the Servel models that several people mentioned. The Servel
also has no moving parts and cools a refrigerator using a propane flame.
There is a factory near us that repairs Servels and look alikes and one of
these days we will get the tube assembly from them (cost is only $170 for a
repaired unit) and try to make an A.T. model. It looks quite do-able to
heat with sunlight, or wood.

The Icy-Ball we built was made from propane cylinders, 5 and 3 gallon, with
a pipe welded between the two. Three gallons of 60% ammonia and 40% water
were placed in the device after evacuating the air. After 90 minutes of
heating on a Rocket stove we cooled 2 gallons of water and antifreeze 44
degrees F. The temperature of the water and antifreeze after two firings
got down to 15 degrees F.

The Icy-Ball did not seem TOO dangerous. Operating pressure was around 140
PSI. But if someone left it on the stove for maybe four hours the pressure
would start to rise to dangerous levels. That's what convinced Larry, a
cautious fellow, that our A.T. soldered safety relief device was perhaps
not reliable enough. We never turned it over to the rigors of daily use at
Aprovecho Research Center for this reason.

Since the Servel system uses simple tubes and doesn't require manual
lifting of the device as with the Icy-Ball we are both intrigued and will,
eventually, follow up this seemingly easy way to make cold from heat.

It would be a great project for someone with a bit more time!

Dean Still

----------
> From: T J Stubbing <heat-win@mcmail.com>
> To: stoves <stoves@crest.org>
> Subject: Icy Ball
> Date: Saturday, October 31, 1998 11:09 PM
>
> Dear Stovers,
>
> Regarding the messages on this from Elsen Karstad and others, before
> electricity came to up-country Nigeria where I lived in the 1950's we
> all had commercially available refrigerators with a kerosene flame below
> an open tube which I assume passed through an ammonia filled,
> automatically pressurising and de-pressurising heat pump extracting heat
> from the products and making plenty of ice cubes for our 'sun-downers'!
>
> Electrolux in Sweden and other manufacturers made these units which were
> trouble-free in operation, and are no doubt still making them for areas
> without electricity. They could presumbaly burn gasification gases
> instead of kerosene and be made larger to provide local cold stores.
>
> Regards,
>
> Thomas J Stubbing
>
> Stoves List SPONSORS and ARCHIVES:
> http://solstice.crest.org/renewables/stoves-list-archive/
> Stoves Webpage
> http://www.ikweb.com/enuff/public_html/Stoves.html
> For information about CHAMBERS STOVES
> http://www.ikweb.com/enuff/public_html/Chamber.htm
Stoves List SPONSORS and ARCHIVES:
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Stoves Webpage
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For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From elk at net2000ke.com Tue Nov 3 06:09:37 1998
From: elk at net2000ke.com (E. L. Karstad)
Date: Tue Aug 31 21:36:09 2004
Subject: Carbonising Sawdust- Downdraft Slab Trial
Message-ID: <v01520d02b264bc4bc965@[195.202.65.50]>

Stovers;

I've been working slowly on constructing a type of downdraft carboniser
that is similar to one that has been tried at KEFRI here in Nairobi, the
major difference being that this prototype uses a wood fire to create the
necessary flue vacuum. The Kahawa charcoal plant here converts coffee husk
to charcoal using a much larger and simpler version. There are many
differences between coffee husk and sawdust- primarily particle size (husks
are like curved fingernails) and moisture content (sawdust is comparatively
hydroscopic).

My first carbonising trial yesterday involved a flat 2 m long by 1.5 wide
cement surface with a curb-sized furrow down the center. Over this 1.25 m
long, 15 cm wide and 15 cm deep gutter I placed a steel sheet with many
lateral slots. A 20 kg mound of dry sawdust is poured onto and completely
covers the slotted plate. The gutter is closed at one end and leads into a
stone 2 m. tall chimney at the other. This is the only entrance into the
chimney from the flat surface side. At the back of the chimney is a sliding
air-tight door that opens into it's base. In here a wood fire is placed on
a grate above where the gutter enters the chimney. Once the fire is burning
the door is closed and glowing coals are sprinkled onto the top of the
sawdust. The fire creates a draft up the chimney by drawing air from
beabeath the sawdust (through the slotted steel plate). This acts to
accellerate the pyrolysis (carbonization) and to burn the smoke
(volatiles) produced by the smoldering heap of sawdust. Additional sawdust
is continuously added as black carbonising patches spread on the surface of
the sawdust heap. This eliminates flames, most of the smoke, and prevents
complete combustion to ash. A furnace-like roaring sound is audible from
within the chimney as proof of the impressive amount of energy being flared
off wastefully in the carbonisation process.

At the end of the trial, the wood fire, which had been replenished a half
dozen times, is allowed to go out and the carbonised mass of sawdust- now
a friable black powder- is turned several times with a shovel to ensure
complete homogeneity of pyrolisis. This does produce an acrid grey smoke-
but not for long. The hot charcoal is shovelled into drums and sealed
(except for a pinhole to prevent vacuum on cooling) in order to ensure the
charcoal is completely extinguished- left overnight.

I'd say that the trial was a limited success with the following results:

-very little smoke evident. None from the chimney- a small amount from the
pyrolysing heap of sawdust. This is a 'clean' process.

-the trial period was 2.5 hours

- 43kg of air dried sawdust was converted to charcoal

- 13 kg of charcoal powder was produced: 30% conversion

- 11 kg of wood was burnt.

The high wood consumption is unnaceptable I realise. As this was the very
first trial with this kiln I hope to be able to reduce wood use in
subsequent tests. This method could concievably be scaled up considerably,
with the major limiting factor being airflow through the fine sawdust
particles.

Note that complete flaring was possible within the base of the chimney in
the absence of secondary air injection.

Today I try the 6-drum downdraft air-injected carboniser. Just sealing it
into place at the moment. Results later.

Some people just never kow when to give up!

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel/Fax:254 2 884437
E-mail: elk@net2000ke.com
_____________________________

From elk at net2000ke.com Tue Nov 3 07:18:51 1998
From: elk at net2000ke.com (E. L. Karstad)
Date: Tue Aug 31 21:36:09 2004
Subject: Mid-Burn Report- 6 Drum Air Injected Sawdust Carboniser
Message-ID: <v01520d03b264cf754a0c@[195.202.65.50]>

Wow! Hot! Eureka, I think!

The only way I can control this beast is by pouring in more and more
sawdust into the two carbonising pits- this restricts airflow and the flare
intensity within the 6 meter high (6 drum) chimney.

Kevin- you were right to warn about scaling under high heat. I can't stand
closer than 3 meters from this unit. If it was night-time I bet it'd be
glowing! Before I slowed it down a bit I was afriad of a complete meltdown
with the flaming chimney toppling over into the two circular kilns.

Not a wisp of smoke from the kiln pits- the downdraft suction is very
strong, and the flare must be running a good 3 meters up the chimney.

First indication that this might be the breakthrough we were working toward
was that the whole outside of the chimney burst into flames as the paint on
the drums burnt off. I cannot express my amazement at how much heat is
contained in the pyrolysis gasses produced from a couple hundrd kg of
sawdust......

Unless the front wood-loading door is left ajar, the flare goes out and a
simply unbelievable amount of smoke pours up out of the chimney. I'd be
kicked out of the neighbourhood if this smoke wasn't flared off.

Back to the furnace! I'll present the data tomorrow.

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel/Fax:254 2 884437
E-mail: elk@net2000ke.com
_____________________________

From REEDTB at compuserve.com Tue Nov 3 08:22:09 1998
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:36:09 2004
Subject: Gone a month
Message-ID: <199811030833_MC2-5EE9-57C@compuserve.com>

Thomas B. Reed: The Biomass Energy Foundation
1810 Smith Rd., Golden, CO 80401
303 278 0558V; 303 278 0560F
E-mail: reedtb@compuserve.com

Dear Gasification and Stoves:

I am taking a trip with Robb Walt of Community Power Corp. to India and the
Philippines to investigate gasifiers and stoves. I will be gone (with
Thanksgiving in Long Beach) until Nov. 1. I hate to think how much Email
I'll miss.

Until I return, Esteban Chornet is in charge of GASIFICATION.

Your Moderator, TOM
REED

From larcon at sni.net Tue Nov 3 11:15:24 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:09 2004
Subject: Karstad on Carbonising Sawdust - two ways
Message-ID: <v01540b03b264dc0bce2e@[204.131.233.31]>

Elasen - Congratulations - twice!!

I should probably wait for more data, but let me try several
questions that I will otherwise forget:

1. Could you compare the advantage and costs of stone and metal chimneys
(and possibly brick also).

2. Also compare the air leakage differences - one requiring an opening for
secondary air and the other not. Presumably a taller chimney could allow
you to bleed some secondary air in and have an alternative means of
controlling the rate of pyrolysis.

3. I'd also like some idea of how small the "sparkplug" flames can be, and
whether the final flame can extend back towards the sawdust - or is the
velocity too high to allow that?

Again - its great that you haven't given up. Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From larcon at sni.net Tue Nov 3 11:15:51 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:09 2004
Subject: Central American disaster of "Mitch"
Message-ID: <v01540b02b264d5c955e0@[204.131.233.31]>

Rogerio:
I am sure that I can speak for all of us on the "stoves" list to
express our sorrow about the tremendous damage that "Mitch" has caused in
Nicaragua and other parts of Central America. The television scenes of the
floods and mud slides are horrendous.

1. How has this calamity affected you or Prolena or other stovers?
2. Is there any specific thing that we on this list can do to assist?
3. Please relay our concerns to those you are assisting.

Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From english at adan.kingston.net Tue Nov 3 20:06:50 1998
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:36:09 2004
Subject: Mid-Burn Report- 6 Drum Air Injected Sawdust Carboniser
In-Reply-To: <v01520d03b264cf754a0c@[195.202.65.50]>
Message-ID: <199811040118.UAA01202@adan.kingston.net>

Dear Elsen and stovers,
This sounds like progress. What does your other unit look like? Send
a picture or drawing if you get a chance.

> Wow! Hot! Eureka, I think!
>
> The only way I can control this beast is by pouring in more and more
> sawdust into the two carbonising pits- this restricts airflow and the flare
> intensity within the 6 meter high (6 drum) chimney.

What about a damper in the gas duct? Going from 20cm diameter chimney
to a 60 cm diameter chimney allows for about a ten fold increase of
flow capacity. The govenor is set pretty high.

Good luck!

Alex

>
> Kevin- you were right to warn about scaling under high heat. I can't stand
> closer than 3 meters from this unit. If it was night-time I bet it'd be
> glowing! Before I slowed it down a bit I was afriad of a complete meltdown
> with the flaming chimney toppling over into the two circular kilns.
>
> Not a wisp of smoke from the kiln pits- the downdraft suction is very
> strong, and the flare must be running a good 3 meters up the chimney.
>
> First indication that this might be the breakthrough we were working toward
> was that the whole outside of the chimney burst into flames as the paint on
> the drums burnt off. I cannot express my amazement at how much heat is
> contained in the pyrolysis gasses produced from a couple hundrd kg of
> sawdust......
>
> Unless the front wood-loading door is left ajar, the flare goes out and a
> simply unbelievable amount of smoke pours up out of the chimney. I'd be
> kicked out of the neighbourhood if this smoke wasn't flared off.
>
> Back to the furnace! I'll present the data tomorrow.
>
>
> elk
>
> _____________________________
> Elsen Karstad
> P.O Box 24371 Nairobi, Kenya
> Tel/Fax:254 2 884437
> E-mail: elk@net2000ke.com
> _____________________________
>
>
> Stoves List SPONSORS and ARCHIVES:
> http://solstice.crest.org/renewables/stoves-list-archive/
> Stoves Webpage
> http://www.ikweb.com/enuff/public_html/Stoves.html
> For information about CHAMBERS STOVES
> http://www.ikweb.com/enuff/public_html/Chamber.htm
>
>

From larcon at sni.net Wed Nov 4 00:41:36 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:09 2004
Subject: Forwarding: Mike Millar on charcoaling
Message-ID: <v01540b03b26596a433ec@[204.131.233.3]>

Stovers: Mike Millar just forwarded this kind offer to assist in our
general efforts to do a better job in making charcoal.

Mike: Thanks very much for your offer. Here are a few questions to start:

1. Yesterday we had two messages from Elsen Karstad that sound
somewhat similar to your approach. As you tell us more, it will be helpful
to describe differences from those two designs (which were for sawdust,
which seems very difficult to convert),
2. Could you describe what you mean by "fail safe"? (and describe
your retort.
3. We'd all like to hear more about activation.

I have taken the liberty of signing you up for the stoves list.
Feel free to drop off if this makes your life difficult - but for awhile, I
think it will help in communication on your designs.

Again. Thanks for making this contact. Ron

>Dear Ronal et al,
>
>Your stovers group has been a help to me in the past and if anyone is
>interested in carbon production I would like to help.
>
>I recently built and operated a reverse draught horno for carbon in Mexico and
>had great success. The horno (oven) built had a capacity of 20000 coconut
>shells and produced 22% product. A retort was also tested and had much better
>and fail safe results. Next stage is activation.

>I look forward to any " stovers" out there who need advice.
>
>Regards,
>
>Mike Millar
>
>taygrc@aol.com

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From lockwood at sep.pradeshta.net Wed Nov 4 04:03:11 1998
From: lockwood at sep.pradeshta.net (Merrick Lockwood)
Date: Tue Aug 31 21:36:09 2004
Subject: \tstov-98\11-04
Message-ID: <36400a7d.sep@sep.pradeshta.net>

4 November 1998 \tstov-98\11-04

To: Tom Reed <REEDTB@compuserve.com>
Ronal Larson <larcon@sni.net>

cc: Stoves list <stoves@crest.org>

From: Merrick Lockwood <lockwood@sep.pradeshta.net>
House 43, Road 23, Banani
Dhaka, Bangladesh

Dear Tom and Ronal,

I have been tuned in on the stoves list for quite some time and I
guess I should be contributing my two cents worth. Tom's
upcoming trip has prodded me to do this now in the hope that this
reaches him before he leaves for India and the Philippines.

I have been involved with Stirling engines since 1979 when I
proposed a project to The Asia Foundation in Bangladesh to
develop a small (5hp) rice husk fueled Stirling engine for use in
rural rice mills. Ultimately this project was funded by the
United States Agency for International Development (USAID) and
ran from 1981 to 1986 as the Rice Husk Energy Project (RHEP). The
design of the Stirling engine was sub-contracted by the Asia
Foundation to Sunpower, Inc. in Athens, Ohio. The engine was
completed in the first year of the project and by 1982 a
prototype rice husk fueled Stirling engine had been designed,
built and demonstrated at Sunpower's facility in Ohio. The
engine had a bore of 300 mm, displacement of 7 liters and was
designed to operate at 5 bar air pressure at 600 rpm.

During the next 4 years here in Bangladesh we went through three
iterations of design modification and fabrication in a facility
we had set up near Dhaka. In this process many snags in the
prototype design were worked out but we continued to have
problems with lack of durability in the Ericsson linkage which
incorporated a bell crank system to drive the displacer. This
mechanism (excluding the crankshaft) had 8 moving parts and 12
bearings. For our last engine which was designed and made in a
crash program during the last 3 months of the project, we re-
designed the engine, switching to a massively built but simple
Ross linkage with only 4 moving parts and 5 bearings. This
engine ran quietly and promised good durability but.... falling
world oil prices and vanishing interest in alternative energy
within the US Govt. scheme of things, scratched funding for
further work.

HOWEVER, the original RHEP Stirling engine design with Ericsson
linkage survived. By 1984 two of Sunpower's people had set up
their own company (Stirling Technology, Inc.) and went into
business with an an Indian company in Madras (Stirling Dynamics)
to manufacture a improved version of the original RHEP prototype.
By incorporating the engine's compressor with the displacer rod
to double as a bounce chamber they hoped to relieve the stresses
that had been fatal for the bellcrank displacer drive mechanism
in the prototype. Their engine, the ST-5, was manufactured for a
period in Madras and generated a lot of interest in India and
abroad. I think about one or two hundred were manufactured. Of
these around 40 were procured by the Indian Government's
Department (now Ministry) of Non-conventional Energy Sources and
put in different locations in India for field testing. The
compressor "fix" worked initially, but when the compressor itself
wore out the linkage again took the load and eventually the
likleyhood of mechanical failure increased. This and other
problems, including increasing costs, eventually put the engine
into mothballs, though some are still being nursed along by a few
dedicated individuals.

Since 1986 I have continued working, part time or full time, on
Biomass fueled Stirling engines. As a matter of convenience I
have aimed at running them on charcoal, thus my interest in the
stoves list. My target engine sizes keep getting smaller, first
to 500-1,000 watts, now the latest is aimed at 100-200 watts for
electricity at the rural household level, perhaps in conjunction
with a cookstove. More on this another time.

The question for Tom is, are you going to be visiting Bangalore?
I suspect you might as Dr. H.S. Mukunda with his combustion and
gasification team at the Indian Institue of Science have done a
lot of work on gasifiers for conversion of biomass to mechanical
power in association with ASTRA. Though maybe you are focusing
on some of the commercial groups who are manufacturing and
selling gasifiers in other parts of India. In a week or so I'm
headed to south India for a few weeks and will be visiting
Bangalore which is not far from where I stay when there. If you
are going to be in that area it would be interesting to meet,
time permitting. Any possibility?

With best regards,

Merrick Lockwood
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From elk at net2000ke.com Wed Nov 4 05:40:57 1998
From: elk at net2000ke.com (E. L. Karstad)
Date: Tue Aug 31 21:36:09 2004
Subject: Results- Sawdust Carbonisation
Message-ID: <v01520d01b265ec2c48d6@[195.202.65.50]>

Here are the results from the successful initial trial run of the 6-drum
sawdust Carboniser:

Duration 2 hours 15 min.
Raw material in: 202 kg airdried 'rough cut' sawdust.
Weight of final carbonised sawdust: 47 kg
Conversion: 23.2%
Kg/hour input: 90
Kg/hour production: 21

This was a short run, with startup and emptying times adding significantly
to the overall burn duration (reducing production rate). We started late in
the afternoon and had a time constraint, so ended prematurely. I'm
scheduling a longer trial for tomorrow morning after the following
modification:

- remove the four 1 inch valved secondary air injector pipes (placed just
above the wood fire) and replace with two 3 inch pipes (valved) located
lower- at the same level as the fire grate. The four smaller pipes were
obviously far too small, as considerable extra secondary air had to be
allowed in via the firebox door in order to flare the volatiles completely.

Ronal- this looks like a pretty even pyrolysis accross the kilns- there's
not enough fresh air mixed with the volatiles to accommodate combustion
without extra secondary air being mixed in.

Alex- I don't follow you on the requirent for a damper in the two gas
ducts. I assume you are referring to the 20 cm dia. ducts leading from
beneath the two kilns to the base of the chimney? I found that control of
the flare was possible by simply increasing the depth of the sawdust bed.
This reduced dowdraft air passage. I plan to see just how much carbonised
material can be amassed in one session tomorrow- if a full 1 meter kiln
depth can be achieved in both kilns. I estimate that'd be just short of 200
kg of carbonised sawdust- about 900 kg raw input. Commercially viable for a
small briquetting industry in E. Africa.

Ronal- I think that reproducing this carboniser in appropriately reinforced
stone or brick (6 m. chimney height) would cost around $2000.00, my current
expenditure is in the region of $350.00 using drums, though I should be
able to further simplify the design and thereby lower the cost of
construction. On the other hand, maybe a much shorter chimney is adequate-
a stone construct would then be preferable, as I imagine that my drums will
burn out pretty rapidly. I'm seriously considering a hybrid- stone base &
combustion chamber) with a drum chimney.

You will be pleased to note, Ronal, that very little (if any) wood is
needed once the wood fire grille becomes incandescent. I used 8.5 kg wood
yesterday, and can reduce consumption further- especially over a longer
burn period as most of wood was used during start-up. With the 3 inch
secondary air injection pipes in place maybe small pieces of wood can be
added through these pipes as required- if required.

I'll be running trials with increased moisture contents in the sawdust. I
think that this kiln can handle sawdust with moisture contents higher than
the air-dried material I'm currently using.

Now- back to the waste heat.... one suggestion I've rec'd is, as
carbonisation will probably take place near a sawmill, could the heat from
the flared volatiles be used for kiln-drying wood? I've never seen a kiln
of this sort, but I'd imagine that the heat would have to be pumped in some
way.

Briquetting of the carbonised sawdust can be performed anywhere, really, as
the cost of transport wouldn't be very high- the mass of charcoal is about
20% or less of the sawdust incl. moisture content.

All for now;

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel/Fax:254 2 884437
E-mail: elk@net2000ke.com
_____________________________

From rmiranda at sdnnic.org.ni Wed Nov 4 17:09:43 1998
From: rmiranda at sdnnic.org.ni (Rogerio Miranda)
Date: Tue Aug 31 21:36:09 2004
Subject: Central American disaster of "Mitch"
In-Reply-To: <v01540b02b264d5c955e0@[204.131.233.31]>
Message-ID: <3.0.2.16.19981104153350.59d734d6@ns.sdnnic.org.ni.>

Dear Ron and all stoves:

Thanks for your concerns. Yes, this hurricane made lots of damage including
lifes, properties, infrastructure and agricuture. Many lifes were lost in
the floods, since river levels increased very fast and in some cases at
night catching people on the bed and not prepared for evacuation. Some
towns were completed devasted by the floods. In some places here in
Nicaragua there was 600 mm of rain in just 7 days, about half of a normal
year rainfall, while in Honduras there was equivalent a full year rainfall
in just about 7 days.

Here in Nicaragua is estimated that 200,000 people were directly affected,
while in Honduras it was 1.5 million people(800 thousand homeless). 1300
lifes were lost in Nicaragua so far (3000 in Honduras), while 2000 others
are still disapeared, it without counting those that live in remote areas
without communication, and we don't know what happenned yet.

Furthemore thousands of houses and and dozens of bridges were washed away.
People found refuge in schools, gymnasiums, churches, etc, while many parts
of the country are unaccessible by road. The priority these past days were
rescuing people by army helicopters and also with some US, mexican and
panamian army helicopters.

Honduras as a whole was affected while in Nicaragua mainly the north,
central and westren parts. Furthemore El Salvador and Guatemala were also hit.

Early assessments indicates that Honduras lost 65% of its agriculture crops
while Nicaragua around 40-50%. The damage in infrastructure is being
compared as if he have gone 20 year back, e.g., we have to reconstruct
what have being built in the past 20 years. In Honduras 70% of its road
infrastructure was damaged.

One of the most dramatic moments was when one hillside of the "Casita"
volcano here in Nicaragua slided and buried several whole communities
including 1000-1500 people as early estimated. It seems that the crater of
the Volcano filled with water and caused the slide, and probably it was
enhanced due the deforestation on it surrounding hills. It seems that will
be to difficult to unburied the bodies, and so the solution appear to be
declare the whole area as a "natural cementery". Incredible, but just near
by, another volcano, the "Cerro Negro" volcano started eruption last night.
Near by communities are beig evacuated.

Here in Nicaragua there has being a big effort within all society to help,
with donations campaign going on everywhere and TV stars doing public
fundraising. Internationsl donors are also starting to respond, including
the friend countries and World Bank, Interamericam Development Bank and Red
Cross.

The imediate needs in all effected countries are helicopters, food, water,
clothes, medicines and reconstruction of bridges and roads. The main
concernes are famine and diseases spread out.

PROLENA/Honduras togheter with two other organizations has stablished an
information center for local emergency committes, while PROLENA/Nicaragua
are working with forest and energy government agencies to speed up projects
requests to international cooperation agencies.

In regard woodstoves, we forsee a great opportunity to include improved
woodstoves as part of the new houses that will be reconstruct in the near
future. I believe we have to be active in this sense, because usualy the
programs for housing reconstruction doesn't see the woodstove as part of
the design neither budget (of course where woodstove makes sense), leaving
to the people the task of building the stove, what usualys ends up just
like the traditional ones.

Perhaps someone in this stove list might have experience in this regard,
e.g, woodstoves components in disaster assistance and reconstruction, and
we would appreciate any advice.

For sure we would like to develop a project in which volunteers or
consultants could come to our region to technicaly assist, as well where we
could raise funds to finance the woodstove component into the rebuilt homes.

If anyone knows of potential donors and volunteers, please let us know.

We thank you for your concerns, and look forward for advices and comments.

Rogerio Miranda

At 10:30 AM 11/3/98 -0600, you wrote:
>Rogerio:
> I am sure that I can speak for all of us on the "stoves" list to
>express our sorrow about the tremendous damage that "Mitch" has caused in
>Nicaragua and other parts of Central America. The television scenes of the
>floods and mud slides are horrendous.
>
> 1. How has this calamity affected you or Prolena or other stovers?
> 2. Is there any specific thing that we on this list can do to
assist?
> 3. Please relay our concerns to those you are assisting.
>
>Ron
>
>Ronal W. Larson, PhD
>21547 Mountsfield Dr.
>Golden, CO 80401, USA
>303/526-9629; FAX same with warning
>larcon@sni.net
>
>
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Rogerio Carneiro de Miranda
ATP/PROLENA/Nicaragua
Apartado Postal C-321
Managua, Nicaragua
telefax (505) 276 2015
EM <rmiranda@sdnnic.org.ni>
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Stoves List SPONSORS and ARCHIVES:
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http://www.ikweb.com/enuff/public_html/Chamber.htm

From foresta at sdnhon.org.hn Thu Nov 5 13:39:02 1998
From: foresta at sdnhon.org.hn (foresta@sdnhon.org.hn)
Date: Tue Aug 31 21:36:09 2004
Subject: (Fwd) Re: HURRICANE MITCH RELIEF EFFORTS
Message-ID: <199811051755.MAA17573@sdnhon.org.hn>

Forwarded message:
From: Self <Single-user mode>
To: @REPLYALL.PML
Subject: Re: HURRICANE MITCH RELIEF EFFORTS
Cc: forestal@sdnhon.org.hn, bioenergia@sdnnic.org.ni, biomass@sol.racsa.co.cr
Date: Thu, 5 Nov 1998 11:37:48

Dear Carmen:

Us the people from Honduras is thanking you for your efforts. We
are passing your information to the Sustainable Development
Network here SDN/PNUD, who has developed an information list to
provide information about MITCH. They also have information on
INTERNET: WWW.webito.com

Some of this information has been already published and you can
find it in WWW.elherald.com, also you can find information on
WWW.sdnhon.org.hn/ayuda.

According to the preliminary reports given by the Comision de
Emergencia, which the President Carlos Flores released last night we
lost because of MITCH 6,420 lives (this figure is growing with new
reports), 11,000 plus are still missing, 84 bridges, 60% of the
infrastructure was destroyed, 812,000 were evacuated from their
homes and we have 599,000 homeless. Many small towns were washed away
by the flooding and fury of the main rivers; Ulua, Choluteca, Aguan,
and others that cross North, Central and Southern Honduras

Only in Tegucigalpa we lost many suburbans (30 Barrios), El
Chile, Miramesi, La Soto, El Pastel, La Hoya, La Isla, Barrio Abajo,
Concordia, La Sagastume, El Manchen, mostly landslides, and
residential areas like Loarque, La Vega, Venezuela, El Prado, La
Maradiaga, Humuya. In Comayaguela the river entered up to the
fifth avenue. Even comercial buildings were destroyed. The principal
markets "Las Americas" and San Isidro and Colon no longer exist.

According to the Private Enterprise Association of Honduras the
damages of the productive industry are around 1 billian US$.
(this includes the industrial sector and angroindustry).

Now, the relief efforts news. We have been receiving the first
shipments from several countries, including our neighbors. Mexico
send 20 aircraft, heavy equipment and even expert rescue teams.

Drinking water , was delivered yesterday to the first barrios in
Comayaguela, to alleviate the suffering of part of the city, today
10 more residenctial areas are recieving water, we hope that in
one or two weeks the mayority of us could have drinking water.

The association of distributions of fuel are doing big efforts to
bring gas and diesel to Tegucigalpa and mayor cities. Yesterday the
first shipments were sent to La Ceiba in a small boat.

Heavy equipment are working to connect the principal highways to
distribute fuel.

The national reconstruction efforts have begun. Honduras is alive
and still standing, it will take many years to recover our losses,
but we still have the will to do what ever it takes to recover.

MITCH RELIEF EFFORTS

Dear Friends:

St. Vincent de Paul has agreed to donate the transportation of the items
we collect.Please distribute this information to all the people you
know. We have the transportation lined up already, so we are
going to start taking donations at Centro LatinoAmericano for Central
America. I am attaching the flyer we are distributing to people. We have
received an overwhelming amount of calls requesting an organize effort
from Eugene. We have formed a "COMITE", mostly from people from Honduras
and Central America. Centro LatinoAmericano is organizing the effort
but the decisions are being made by the "COMITE". We are going to need
many volunteers, if you are interested please call 687-2667 and the
receptionist will take your name and number and we will call you.

THE VICTIMS OF HURRICANE MITCH NEED YOUR HELP:
WHAT'S NEEDED

Small donations can add up to relieve the suffering of millions of
people who are homeless. Right now, canned food that doesn't need
cooking, medicine and drinking water are priorities. The following items
were selected from a list provided by the Honduran Secretary of the
Exterior.

MOST NEEDED:
+ Baby Food, Formula
+ Disposable Diapers ( all sizes)
+ Milk-Powdered or canned (only)
+ Drinking Water
+ Canned Food (fruit, tuna, sardines, tomato sauce, tomato paste,
vegetables)
+ Corn Flour (Masa Harina available in all supermarkets)
+ Beans (packaged red beans, preferably)
+ Rice
+ Vegetable Oil (not in glass bottles) or vegetable shortening or lard
+ Sugar
+ Pasta
+ Salt

MEDICAL SUPPLIES:

+ Anti-diarrhea
+ Decongestants
+ Antipyretics( to lower fever)
+ Pain relievers: Aspirin, etc.
+ Cotton Balls, pads
+ Distilled water
+ Soaps
+ Disinfectants, alcohol, ointments, hydrogen peroxide
+ Rehydration salts

CLOTHING

Remember that winter clothing is needed in very few areas:
+ Clothing for adults and children
+ Protective gear such as heavy gloves, rubber boots, face masks,
goggles, etc.

SHELTER/EQUIPMENT
+ Flashlights, lanterns with batteries
+ Tarps, tents, plastic sheeting
+ Cots and Folding beds
+ Cooking utensils and dishes ( metal or plastic)
+ Can openers!!!!!!!!
+ Portable (gas) stoves, grills
+ Blankets, sheets, sleeping bags
+ Soaps
+ Detergents
+ Chlorine bleach
+ Mosquito Repellent
+ Charcoal
+ Cleaning supplies

NOTE:Be careful about packaging items that are considered dangerous
goods for transportation. Chlorine bleach is a needed item for purifying
water, but is dangerous and shipments must be properly marked.

+ Please bring with your donation clean, sturdy cardboard boxes.

All items that are donated will be packaged and delivered to the
Consulate of Honduras in LA. If you want your aid to go to El Salvador,
Guatemala, or Nicaragua, put it in a box and mark it "Hurricane Mitch"
and the name of the country. The Honduran Consulate will arrange for the
respective consulates to pick up the boxes. Cash donations to purchase
goods for shipment should be made payable to Hurricane Mitch Relief Fund
and can be sent to the Centennial Bank-Main Branch. P.O. Box 1560,
Eugene, OR 97440 Please specify the country you want the aid to go to.

If the item donations or cash donations are not clearly marked with what
country you want them to go to, they will be sent to Honduras.

For more information please call Centro LatinoAmericano at :
Phone: 541-687-2667
Fax: 541-687-7841
E-mail: centrola@efn.org

DONATIONS ACCEPTED: MONDAY -FRIDAY: 8:30 to 6:30
SATURDAY:
9:00 to 2:00
SUNDAY: 10:00 to
2:00
944 W 5th Ave.
Eugene, OR 97402

White building with red trim in between Adam and Blair on 5th Ave.
If you would like to make a delivery at any other time please call
687-2667 and we will make special arrangements.
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From larcon at sni.net Thu Nov 5 21:51:05 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:09 2004
Subject: Forward ANDREW SARTAIN on charcoal history
Message-ID: <v01540b00b2680ec91429@[204.131.233.15]>

Stovers: The following message in today from Andrew Sartain asking for
help on several issues related to charcoal.

Andrew: I have an interesting history from about one hundred years ago on
the large scale manufacture of charcoal in Nevada (for smelting). This was
a recent doctoral thesis and is very complete as to what was happening at
that time around the world. The use of fixed brick and metal kilns was
becoming more widespread, but was not considered economic in Nevada - I
believe because the wood supply was relatively sparse and labor was
relatively cheap.

I hope you will keep this list informed on what you learn on your
several topics. We are especially interested in flaring of the pyrolysis
gases as opposed to simply venting.

I am taking the liberty of signing you up for "stoves". Let me
know when you feel you have had enough of our discussion on charcoaling.
We are about 150 in 35 different countries.

Ron

>
>Dear stovers,

>I am currently doing a scientific analysis of charcoal, comparing the
>results of tests with charcoal from the tropics and Europe and the U.K.
>If anyone has a history of charcoal production in the U.K. to hand I
>would be eternally grateful.

>I am also looking for statistics for global charcoal production and the
>state of the industry with respect to fuelwood supply in the future.

> Regards Andrew Sartain
>My other e-mail address is a.g.t.s@tesco.net
>
"ANDREW.SARTAIN" <n6111048@buckscol.ac.uk>

From larcon at sni.net Fri Nov 6 00:50:09 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:09 2004
Subject: Forwarding (#2): Mike Millar on charcoaling
Message-ID: <v01540b07b268335cac15@[204.131.233.34]>

Stovers: The following in yesterday from Mike Millar, in response to my
request for more information:

Mike: Thanks.

1. I think I understand your approach. Certainly I do in general
and I like the general idea. However, we will all benefit if you can send
any photos or plans to Alex English: english@adan.kingston.net, or start by
looking at his webpage at

http://www.ikweb.com/enuff/public_html/Stoves.html

2. Can you turn your conversion numbers into a percent by weight
value? How much would 1500 coconut shells weigh?

3. It sounds like you had to vent for awhile and so there was some
pollution. Can you estimate what the percentage time was in the venting
and flaring modes?

4. Might it be possible to stack the barrels vertically and allow
a continuous operation, with the more recent (upper) additions being
vented, but "combusted" by the lower flared units?

5. Yes, it would be interesting to hear about the "horno" as well.

(The rest is from Mike:)

Dear Ron,

The retort I built sounds similar to Elsens in that it is( 3 ) 55 gallon
barrels welded together end on end. 2 were built to total 6 drums and run side
by side. (2 retorts)

One end of the retort was left sealed and the other was clamped shut using
standard barrel clamps.The bung holes were left with the caps on sealing the
unit. On the bottom of the barrels 16" back from the front a 3" pipe was
welded on a 45 degree angle extending 10 " towards the fire pit.
The retorts (barrels) were laid on the sides, parallel supported on 3 - 4" I-
beams.

Previous a trench was dug 2 feet deep for the coconut husks which were used as
fuel, or heat source. The fire was lit and maintained for 2-3 hours while
steam and white smoke was abundant. After 3 hours the carbon reached tempature
to drive off volatiles.( tars ) At this stage the combustibles ignited and
shot flames out the 3 " pipes fueling the fire so no more husks were added.
When the flame went out the combustion was complete making an excellent
charcoal . This is what I meant by fail-safe as unskilled labor could do it
with no worry of over-cooking and turning the retort into a big BBQ. The end
of the barrel was removed and carbon unloaded ( no cooling time) and reloaded
with coconuts to repeat. ( 2 burns a day)

In total 1500 coconut shells were carbonized yeilding 100 kilos carbon.

If interested, I will explain the big horno and activation.

Regards, Mike

From larcon at sni.net Fri Nov 6 00:50:13 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:09 2004
Subject: Results- Sawdust Carbonisation
Message-ID: <v01540b08b26838bcef6c@[204.131.233.34]>

Elsen: This is picking up on your Wednesday message. Again
congraulations. it seems like you have worked most of the basic problems
out. You said:

>Here are the results from the successful initial trial run of the 6-drum
>sawdust Carboniser:
>
<snip>

>Now- back to the waste heat.... one suggestion I've rec'd is, as
>carbonisation will probably take place near a sawmill, could the heat from
>the flared volatiles be used for kiln-drying wood? I've never seen a kiln
>of this sort, but I'd imagine that the heat would have to be pumped in some
>way.

This sounds like a great use - especially for the sawmill owner.
The only thing I can add is that some wood fired masonry heating stoves
have what seems to me to be incredibly long chimney runs back/forth or
around a large house - thereby transferring heat to the (storage) brick in
the chimney. Maybe that idea is possible also for your output flared
gases. Maybe a good bit of the run can be through a (cheap?) trough dug in
the ground with costs mainly for the trough cover. The wood would have to
be carefully stacked the right distance away from this "chimney" (hopefully
avoiding the need for electricity for blowers).

Maybe some of the masonry heating stove experts on the list can
tell us what reasonable dimensions and lengths can be for such long
extensions of a chimney.

Congratulations and Best of luck. Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From elk at net2000ke.com Fri Nov 6 02:27:20 1998
From: elk at net2000ke.com (E. L. Karstad)
Date: Tue Aug 31 21:36:09 2004
Subject: Sawdust Carbonisation- Second Trial
Message-ID: <v01520d01b26870c22ab4@[195.202.65.85]>

Stovers;

Yesterday's trial results were as follows:

552 kg sawdust carbonised
Two batches- 2.5 hours each.
Down time to emptying & filling- 2 hours
Charcoal produced- 129.7 kg
Conversion: 23%
Depth of carbonised product in kiln at end of batch- 25 cm.
Wood used- 8 kg/batch (16 kg tot.)

With increased efficiency, production rate can be almost doubled- this was
only the second time this kiln has been used.

Flaring of volatiles became increasingly difficult over 20 cm carbonised
product depth in the kilns- due to restricted downdraft airflow I assume. A
'flame-out occurred on a couple of occasions and was corrected by the
addition of more wood in the base of the chimney. It is apparent that the
use of wood (or similar) to maintain the flaring of volatiles is essential.

So far the metal drums have withstood the intense heat of flaring.

I'm going back to my other carboniser- the cement platform with a central
gutter- the other downdraft system I described a few days ago. I'll see if
I can improve the performance of this system.

If it looks promising I am working on the design of a hybrid between the
two systems.

Picture this: An array of 5 or 6 platforms with gutters that collect
volatiles beneath a perforated plate. The downdraft volatiles are convected
through 20 cm dia. valved pipes to a central stone/cement firebox/chimney
base. The chimney itself is made up of 6 or seven drums (6 ot 7 m. tall
plus the hieght of the firebox). Secondary air injection is controllable.

I don't believe that it is necessary for the kilns to have a cement base.
Compacted and possibly stabilised earth should be O.K. Also- the gutters
could be replaced with an above-ground well-perforated hemispherical
light-guage sheet metal pipe (maybe 50 cm wide and 10 cm high-sealed at the
distal end). Kiln walls may not be necessary if the carbonising sawdust is
placed evenly in a mound over the half-pipe. Sadust is added by hand as the
black caronising sawdust shows on the surface.

This setup should be cheaper to construct in terms of output while the
stone & cement base lasts longer under the intense heat of the flaring
volatiles. This provides a continous batch-wise operation over the 5 or
six kilns. Each can be isolated from the chimney by a simple valve of some
sort while being harvested or replenished with fresh sawdust.

It'd be easy to run a few pipes through this unit to produce steam- but for
what? Any ideas?

Is there such a creature as a pyromaniac ecologist?

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel/Fax:254 2 884437
E-mail: elk@net2000ke.com
_____________________________

From kchishol at fox.nstn.ca Fri Nov 6 22:52:19 1998
From: kchishol at fox.nstn.ca (kchishol)
Date: Tue Aug 31 21:36:09 2004
Subject: Sawdust Carbonisation- Second Trial
In-Reply-To: <v01520d01b26870c22ab4@[195.202.65.85]>
Message-ID: <3643C677.17722190@fox.nstn.ca>

Dear Elk

Glad to see your encouraging results!!

Because of your different sizes of kilns, and different charcoaling times, may
I suggest that you develop an index for each run, so that we could all better
appreciate your progress? Such indices would also be very helpful to you, in
evaluating the relative success of your many test configurations.

I would suggest two key numbers:
1: Kilograms per square meter per hour of saleable charcoal.
The time used would be the time from the start of one charge of sawdust, to
the time of the start of the next charge.

2: The % charcoal yield based on the weight of the starting sawdust.

"E. L. Karstad" wrote:

> Stovers;
>
> Yesterday's trial results were as follows:
> ....del....
> With increased efficiency, production rate can be almost doubled- this was
> only the second time this kiln has been used.

What do you mean by "increased efficiency?" Do you mean increased draft?

> Flaring of volatiles became increasingly difficult over 20 cm carbonised
> product depth in the kilns- due to restricted downdraft airflow I assume.

Right on!! I guess the reduced rate of volatile production results in a drop in
the temperature of the volatiles, so that ignition temperature cannot be
maintained.

> A
> 'flame-out occurred on a couple of occasions and was corrected by the
> addition of more wood in the base of the chimney. It is apparent that the
> use of wood (or similar) to maintain the flaring of volatiles is essential.

Rather than burn wood, why not simply use the flameout condition as an
indicator that this is "the end of the run?"

> So far the metal drums have withstood the intense heat of flaring.

Why not line them with 2" of local fireclay? This will extend life, and improve
on draft by reducing heat loss. If the steel is red hot, it will scale itself
to deat in short order. You should try a run at night to see the hot spots
better.

> I'm going back to my other carboniser- the cement platform with a central
> gutter- the other downdraft system I described a few days ago. I'll see if
> I can improve the performance of this system.
>
> If it looks promising I am working on the design of a hybrid between the
> two systems.
>
> Picture this: An array of 5 or 6 platforms with gutters that collect
> volatiles beneath a perforated plate. The downdraft volatiles are convected
> through 20 cm dia. valved pipes to a central stone/cement firebox/chimney
> base. The chimney itself is made up of 6 or seven drums (6 ot 7 m. tall
> plus the hieght of the firebox). Secondary air injection is controllable.

Lotsa interesting opportunities here!!!
1: Why not use 6-45 gallon drums with slotted bottoms, each sitting on a valved
pedestal, connected to a common set of flue runs?
This way, you could have 6 individual stoves going at once, and as one got
its charcoaling task complete, the isolation valve could be shut off, and the
entire drum could be lifted for dumping the hot charcoal into the steel cooling
drums. When dumped, it would be set back on its base, filled with new sawdust,
and ignited for repetition of the process. The attendant could then move to the
next drum and repeat the process.

2: You should consider adding some secondary air UNDER the above assembly, if
tramp air inleakage is insufficient to acomplish this, to keep the flue runs
hot, and the volatiles above the ignition point.

> I don't believe that it is necessary for the kilns to have a cement base.
> Compacted and possibly stabilised earth should be O.K.

Sure!! Should be quite good. Consider using a local fireclay..... any local
clay that will stick together for forming, and after drying and heating, will
suffice.

> Also- the gutters
> could be replaced with an above-ground well-perforated hemispherical
> light-guage sheet metal pipe (maybe 50 cm wide and 10 cm high-sealed at the
> distal end). Kiln walls may not be necessary if the carbonising sawdust is
> placed evenly in a mound over the half-pipe. Sadust is added by hand as the
> black caronising sawdust shows on the surface.

I can't quite picture tha above, but heres another suggestion: Make a cone
shaped bottom for the 45 gallon drums, with the angle of the cone equal to the
angle of repose of the sawdust. Then use a "sawdust funnel" to continuously
charge the system. For example, assume the "drum cone is at 45 degrees, and
that a bed depth of 15 cm is the maximum permissable. A 10 cm sawdust feed pipe
located
15/Cos 45 = 15/.707 = 21 cm above the apex of the drum cone would ensure
that the cone was uniformly covered with 15 cm of (sawdust + charcoal) As the
sawdust carbonized, it would thin out, and allow more sawdust to flow in,
automatically. When the surface appeared black, thats the time to stop the
charge, and dump the stove.

> This setup should be cheaper to construct in terms of output while the
> stone & cement base lasts longer under the intense heat of the flaring
> volatiles. This provides a continous batch-wise operation over the 5 or
> six kilns. Each can be isolated from the chimney by a simple valve of some
> sort while being harvested or replenished with fresh sawdust.

Right on!! The big improvement will be the ability to improve on materials
handling, and the continuous gravity feed of sawdust on an "as required basis

> It'd be easy to run a few pipes through this unit to produce steam- but for
> what? Any ideas?

Do not take any heat from the unburned off-gases from the charcoaling
operation.... you will encourage condensation of volatiles, and will make a
very messy mess of pyroligneous liquors. Take heat off the hot stack gases.
BUT, be careful how much you take.... you don't want to materially lower stack
temperature. Steam is much more difficult to produce controllably than is hot
water. You could generate hot water, and run it through an old car radiator, to
produce hot air for sawdust drying. How do you dry your sawdust now? Your
yields should improve with less moisture present. The water gas reaction eats
charcoal, as follows:

H20 + C = CO + H2

Each 18 kg of water you don't dry off eats 12 kg of charcoal. How do you dry
your sawdust now? Have you considered using your stack gases as a source of
heat for drying wet sawdust? You will need a fan to do this.

> Is there such a creature as a pyromaniac ecologist?

Aren't we all??? :-)

Kevin Chisholm

From larcon at sni.net Fri Nov 6 23:43:19 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:09 2004
Subject: Forward to ANDREW SARTAIN on charcoal history
Message-ID: <v01540b04b2696b9bca41@[204.131.233.33]>

Stovers - the following is from list member Thomas Stubbing.

Thomas - Thanks for sending this message on. This bounced to me because
your address for this message was different from the way you signed up on
the list. Let me know if I should make a change for you.

(The remainder of this is all from Thomas)

Dear Stovers and Andrew Sartain,

Within his message to Ronal W Larson Andrew Sartain wrote:

>If anyone has a history of charcoal production in the U.K. to hand I
>would be eternally grateful.

The best short history I have found so far of charcoal production globally, but
mainly in the UK, is 'Charcoal and Charcoal Burning' by D W Kelley, published
as Shire Album 159, ISBN 0-85263-731-4, by Shire Publications Ltd., Cromwell
House, Church Street, Princes Risborough, Buckinghamshire HP27 9AA, UK at the
modest price of around £3-00 including postage.

I hope this helps.

Regards,

Thomas J Stubbing

From larcon at sni.net Fri Nov 6 23:43:19 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:09 2004
Subject: Sawdust Carbonisation- Second Trial
Message-ID: <v01540b05b26972004abf@[204.131.233.33]>

Elsen -

I like your new results and new ideas

You said:

<snip>

>With increased efficiency, production rate can be almost doubled- this was
>only the second time this kiln has been used.

(Ron): I hope you can continue to keep records on productivity for awhile.
For many products, each doubling of cumulative output leads to the same
percentage reduction of "costs" (or time). There are not many products
where the data is available from the very first unit. For many products
that percentage reduction is about 20%.
>
<snip>

>I don't believe that it is necessary for the kilns to have a cement base.
>Compacted and possibly stabilised earth should be O.K. Also- the gutters
>could be replaced with an above-ground well-perforated hemispherical
>light-guage sheet metal pipe (maybe 50 cm wide and 10 cm high-sealed at the
>distal end). Kiln walls may not be necessary if the carbonising sawdust is
>placed evenly in a mound over the half-pipe.
<snip>

(Ron): These last two ideas are really great. I wonder if standard big
collanders or strainers might do the job. I didn't understand the phrase:
"sealed at the distal end".

<snip>
>
>It'd be easy to run a few pipes through this unit to produce steam- but for
>what? Any ideas?
>
(Ron): Maybe making ice?

>Is there such a creature as a pyromaniac ecologist?

(Ron): In Colorado, you'd better use "pyrologists" or
"pyrological". We've just had major news here on the assertion (no proof)
that "ecologists" had torched a major ski area.

Good luck. Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From NFPWest at aol.com Sun Nov 8 22:07:41 1998
From: NFPWest at aol.com (NFPWest@aol.com)
Date: Tue Aug 31 21:36:09 2004
Subject: A short plea for Central America
Message-ID: <abe6624b.36465f11@aol.com>

From: Richard Fox
National Director
Trees, Water & People

Dear Friends,

It is a time to reach out to help provide the immediate survival needs
of our neighbors in Central America. After this disaster and the water
has receded though, Trees, Water & People will continue our work in the
forests and watersheds of Central America. Maybe this most recent
devastation will bring a greater focus on the need to reforest the steep
slopes where thousands recently lost their lives.

In the early 1990's, I supervised a project that planted over a million
trees around the Honduran capital of Tegucigalpa. In 1995, my colleagues
and I began a long-term project to protect Honduran forests with a focus
on treeplanting projects in those watershed areas that provide Honduran
towns and villages with fresh drinking water. We also have tree nursery
programs and full time staff in Guatemala and El Salvador and an
exceptional tree seed nursery that provides an abundance of trees seeds
for our nurseries.

What we need is YOUR support to expand these programs RIGHT NOW. If we
can get our local forestry extensionists working with the impacted
communities as they try to rebuild their towns and villages, we can be
part of the planning process and better prevent these tragedies from
occurring again. But we need to get our foresters in the field AS SOON
AS POSSIBLE, so we can get trees in the ground and growing THIS year.
We are ready for a major expansion of our treeplanting efforts... but we
need YOUR help to make it possible.

Your support at this critical time will make a world of difference to
many people in Central America who have a real and desperate need for
hope and a more secure future. Please feel free to call or email me
personally for more information. Please send your donations to:

Trees, Water & People
633 S. College Avenue
Fort Collins, CO 80524

Phone - (970) 484-3678
rcfox@econet.org
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From larcon at sni.net Mon Nov 9 16:32:06 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:09 2004
Subject: Forwarding: densification information request
Message-ID: <v01540b06b26d0921acca@[204.131.233.26]>

Stovers: I know a similar request was answered some time ago, but I don't
remember the responder or date. Can anyone help? (Responding to the full
list will probably be of help to many.) Ron

Lourdes - Welcome to the stoves list.

>X-Sender: lourdes@dombosco.merconet.com.br
>Date: Mon, 02 Nov 1998 12:49:20 -0200
>To: owner-stoves@crest.org
>From: Lourdes Soffner <lourdes@dombosco.merconet.com.br>
>Subject: information
>Mime-Version: 1.0
>X-MIME-Autoconverted: from quoted-printable to 8bit by lynx.sni.net id KAA09654
>
>Please,
>
> I am research at Escola de Agricultura "Luiz de
>Queiroz"/Universidade de
>São Paulo/Brazil.
> I need some information about biomass densification (process and
>equipament for briquets, pellets, etc).
>
> Thank you very much,
>
> Lourdes Soffner

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From elk at net2000ke.com Tue Nov 10 04:31:13 1998
From: elk at net2000ke.com (E. L. Karstad)
Date: Tue Aug 31 21:36:09 2004
Subject: Sawdust Carbonisation- Ongoing Discussion
Message-ID: <v01520d00b26dcedb35ad@[195.202.65.42]>

Kevin's comments:

Standardising the data is a good idea. The following information was
presented for the last trial:

552 kg sawdust carbonised
Two batches- 2.5 hours each.
Down time to emptying & filling- 2 hours
Charcoal produced- 129.7 kg
Conversion: 23%

I calculate the surface area within the two kilns to be 6.3 square meters:

2.51 kg/m2/hr charcoal produced (incl.downtime between the two batches).

This is interesting- therefore at this rate the proposed array of five
flat-bed gutter type kilns totalling 27 m2 (fired in rotation) would
convert 2.36 tons of sawdust into 542 kg of charcoal in one 8 hr. shift.
Adding 25% clay as binder would result in the production of 677 kg of
briquettes with the same burning charactaristics as the product I'm
currently producing with vendor's waste fines.

This is getting scary! The amount of heat produced at this rate of
conversion will be astronomical.

Which brings us to another of Kevin's comments:

>Why not line (the chimney) with 2" of local fireclay?

I agree that something will have to be done to protect metal from this
intense heat, but I've no experience with fireclay of any sort- I think a
cement/stone chimney with a good 3 m. tall combustion chamber is the
easiest solution- of a diameter in excess of the original drums I have
used. On top of this could be placed an additional chimney extension of 4
drums- easily replaced. Total unit height approx. 7 m.

> What do you mean by increased efficiency?

I meant quicker loading and emptying of kilns, faster ignition, and no more
'flame-outs' until the end of the batch. Increased operator efficiency.
With a sequential array design flaring would hopefully be continuous.

On 'Flameouts':

A wood fire 'sparkplug' is evidently still required for continuous flaring
of the volatiles. Variables such as wind, the addition of more sawdust to
the kiln and increasing char depth in the kiln over the duration of the
burn results in an uneven 'gas' supply to the combustion chamber. I'm
fairly confident that with time and attention (particularly to secondary
air injection) the requirement for a wood fire could be limited to the
initial ignition period. Possibly kerosene could be used instead of wood if
there's any advantage.

On Secondary Air:

I've had a couple 'blow-backs' where the volatiles very briefly ignited
under the kilns. Obviously from to much 'tramp' secondary air leaking in.
This was resolved by pouring water on the soil sealing the edge of the
kilns- improving the seal. I feel it is important to confine combustion to
the base of the chimney and wonder if anybody knows of a suitable 'flame
trap' for a 20 cm. dia. pipe...? The valves between chimney and kiln on
these pipes will probably be simple butterfly dampers in-line.

At present the secondary air is injected via two short 2 in. dia. pipes at
the level of the wood fire grate. Any suggestions on improvements here? I
feel that some attention could be paid to the design and 'carburation' of
the combustion zone in the lower half (cement/stone section) of the
chimney. I think the flaring should be maintained as it is- a long vertical
flame extending a considerable way up the chimney- preferrably above the
wood fire in order to conserve wood.

Kevin's design ideas involving drums and cones- flow-through systems- is
worth considering. I'll toss that between left & right lobes for a
while.....

I'm amazed at the effect of moisture on the conversion of sawdust to
charcoal- I air/sun dry the sawdust to ambient- about 10% I guess. I've
carbonised some fairly moist sawdust and observed the expected- slower
rates and difficulty in flaring the volatiles, but I didn't realise that
water ATE carbon!

Ron: Your comments on record-keeping are noted. I'll do my best.

My description of the array flat-bed kiln, where above-ground slotted
half-pipes replace the gutter for collecting volatiles was confusing-
sorry. The hemi-spherical collector pipe is not open-ended, but sealed at
it's distal end. It leads to the round 20 cm dia pipe, past a butterfly
valve and into the base of the chimney/combustion chamber.

All for now- I'm starting to produce some sketches for the proposed
flat-bed array sawdust carboniser.

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel/Fax:254 2 884437
E-mail: elk@net2000ke.com
_____________________________

From english at adan.kingston.net Wed Nov 11 12:58:01 1998
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:36:10 2004
Subject: Elsen's Pictures
Message-ID: <199811111810.NAA30127@adan.kingston.net>

Dear Stovers,
Some pictures of Elsen's 6-drum carboniser are now posed on the
Stoves Webpage.

Alex

From cknowles at igc.org Wed Nov 11 17:12:30 1998
From: cknowles at igc.org (Cynthia Knowles)
Date: Tue Aug 31 21:36:10 2004
Subject: Wood stoves/GHG
Message-ID: <2.2.16.19981111172326.35d77f5a@pop.igc.org>

To: Members of stoves and bioenergy lists
Re: Request for information on link between wood stoves and GHG

Do any list members have information or know of info. sources on wood
burning stove emissions and their contribution to the overall concentration
of greenhouse gases?

Thank you in advance,
Cynthia Knowles
******************************************
Cynthia L. Knowles
E-mail: cknowles@igc.apc.org
Enersol Associates, Inc.
A Member of
The Global Transition Group
55 Middlesex Street, Suite 221
North Chelmsford, MA 01863 USA
Tel: (978)251-1828/29; Fax: (978)251-5291

From kchishol at fox.nstn.ca Wed Nov 11 17:29:13 1998
From: kchishol at fox.nstn.ca (kchishol)
Date: Tue Aug 31 21:36:10 2004
Subject: Wood stoves/GHG
In-Reply-To: <2.2.16.19981111172326.35d77f5a@pop.igc.org>
Message-ID: <364A124D.EF12E23F@fox.nstn.ca>

Dear Cynthia

Cynthia Knowles wrote:

> To: Members of stoves and bioenergy lists
> Re: Request for information on link between wood stoves and GHG
>
> Do any list members have information or know of info. sources on wood
> burning stove emissions and their contribution to the overall concentration
> of greenhouse gases?

I don't know where you can get your requested links, BUT basically wood burning
makes ZERO contribution to the Greenhouse Gas problem. The simple reason is
that it is only the addition of new carbon to the biosphere which aggrivates
the greenhouse gas (CO2) content of the atmosphere. The CO2 emissions resulting
from wood combustion came from the present biosphere in the growth phase, and
are liberated to it, on combustion.

One can make the argument also that burning wood results in less GHG impact
than does not burning it. The reason is that if it is not burned, it rots, and
a significant percentage of the rot products can be methane, CH4, which is
about 20 times as effective a greenhouse gas, as is CO2 resulting from
combustion.

Kindest regards,

Kevin Chisholm

From john at gulland.ca Wed Nov 11 17:48:07 1998
From: john at gulland.ca (John Gulland)
Date: Tue Aug 31 21:36:10 2004
Subject: Wood stoves/GHG
In-Reply-To: <2.2.16.19981111172326.35d77f5a@pop.igc.org>
Message-ID: <000601be0dc6$ceed5aa0$2636f8ce@jgulland.igs.net>

Cynthia,
I host this web site: http://www.wood-heat.com/index.htm
It has a paper called Residential Wood Heating: the Forest, the Atmosphere and
the Public Consciousness. It is here: http://www.wood-heat.com/forest.htm
It also has an article called All About Wood Smoke, which you can find here:
http://www.wood-heat.com/smoke.htm

Hope this helps. If you want more information, just let me know.
Regards,
John
This is for business: http://www.gulland.ca/
This is for pleasure: http://www.wood-heat.com/

> -----Original Message-----
> From: owner-stoves@crest.org [mailto:owner-stoves@crest.org]On Behalf Of
> Cynthia Knowles
> Sent: Wednesday, November 11, 1998 5:24 PM
> To: stoves@crest.org; bioenergy@crest.org
> Subject: Wood stoves/GHG
>
>
> To: Members of stoves and bioenergy lists
> Re: Request for information on link between wood stoves and GHG
>
> Do any list members have information or know of info. sources on wood
> burning stove emissions and their contribution to the overall concentration
> of greenhouse gases?
>
> Thank you in advance,
> Cynthia Knowles
> ******************************************
> Cynthia L. Knowles
> E-mail: cknowles@igc.apc.org
> Enersol Associates, Inc.
> A Member of
> The Global Transition Group
> 55 Middlesex Street, Suite 221
> North Chelmsford, MA 01863 USA
> Tel: (978)251-1828/29; Fax: (978)251-5291
>

From kchishol at fox.nstn.ca Wed Nov 11 23:17:58 1998
From: kchishol at fox.nstn.ca (kchishol)
Date: Tue Aug 31 21:36:10 2004
Subject: Theoretical Yield of Charcoal
Message-ID: <364A6413.59260B82@fox.nstn.ca>

Elk is getting in the order of 25% charcoal yield from his
sawdust charcoal operation. If the theoritically attainable
maximum yield was 26%, he is doing phenomenal. However, if
the theoretical maximum is 50%, then he has lotsa
opportunity for improvement.

I would hypothesize that the maximum yield attainable in a
real world operation would be from a charcoal retorting
operation, running on bone dry sawdust. Would anyone have
data on what yield could be expected in this case?

The next question is a bit more difficult.: How can
pyrolysis gases be processed to recover carbon?
Specifically, the so-called "creosote" is a low grade form
of "wood coke", in that it still has some volatiles present.
The creosote or wood tar fraction is basically a complex
C-O-H compound of some sort. If the -O-H elements could be
removed, then there would be an additional yield of solid C.
How can this be done? How much additional carbon yield could
be attained, if this was possible?

Kevin Chisholm

From dgill at myhost.ccsinc.com Thu Nov 12 01:42:47 1998
From: dgill at myhost.ccsinc.com (Dan Gill)
Date: Tue Aug 31 21:36:10 2004
Subject: Theoretical Yield of Charcoal
In-Reply-To: <364A6413.59260B82@fox.nstn.ca>
Message-ID: <364A86EB.C3731BF0@myhost.ccsinc.com>

kchishol wrote:
>
> Elk is getting in the order of 25% charcoal yield from his
> sawdust charcoal operation. If the theoritically attainable
> maximum yield was 26%, he is doing phenomenal. However, if
> the theoretical maximum is 50%, then he has lotsa
> opportunity for improvement.

I am one of the non-technical members so my figures are rule-of-thumb. I
believe that 25% is good for a direct burn. From the figures I have
seen, about 2/3 of the BTUs in wood are contained in the volatiles
leaving 1/3 in the charcoal. Assuming a linear relationship of weight to
BTUs the theoretical max yield is between 30-35% (dry basis) for most
woody biomass.

> I would hypothesize that the maximum yield attainable in a
> real world operation would be from a charcoal retorting
> operation, running on bone dry sawdust. Would anyone have
> data on what yield could be expected in this case?

I can consistently get about 33% charcoaling wood (sawmill waste @ <15%
MC) in a drum retort. This does not include the scrap wood and bark I
use to heat the retort. Pyrolysis gasses are burned under the retort and
provide most of the heat. See my method at:
http://members.tripod.com/~DanGill/Charmake.htm

> The next question is a bit more difficult.: How can
> pyrolysis gases be processed to recover carbon?
> Specifically, the so-called "creosote" is a low grade form
> of "wood coke", in that it still has some volatiles present.
> The creosote or wood tar fraction is basically a complex
> C-O-H compound of some sort. If the -O-H elements could be
> removed, then there would be an additional yield of solid C.
> How can this be done? How much additional carbon yield could
> be attained, if this was possible?

I have no experience with this but wood has been distilled for centuries
to recover tars, alcohols etc. I would try running the vapors through a
long inclined tube to cool them - maybe with a water jacket. Blowers
would be required to move combustion air and maintain velocity. If you
can keep creosote from clogging your tube, nasty black stuff should drip
out of the end.

Dan Gill
--
De Gustibus non es disputandem - One shouldn't argue about taste.
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From ececelski at t-online.de Thu Nov 12 02:06:01 1998
From: ececelski at t-online.de (Elizabeth Cecelski)
Date: Tue Aug 31 21:36:10 2004
Subject: GHG emissions
Message-ID: <364AE6E7.6DA5@t-online.de>

Hello Cynthia,
Re your query about GHG emissions of woodstoves, I just came across a
RWEDP study

Regional Study on Wood Energy Today and Tomorrow in Asia

that discusses GHG implications of wood energy use in Asia. It
estimates that in 1994 emissions of some 560,000 kton of CO2 was avoided
by the use of woodfuels as compared to coal as a (hypotheitical)
alternative. Their web page is www.rwedp.org, I think the report may
even be posted there.

I also recall a short article in Boiling Point (ITDG/GTZ) some time ago,
by a TERI researcher I think, on possible GHG savings from more
efficient stoves.

I would be interested in your findings, good luck, Elizabeth

Good luck, Elizabeth

--
Elizabeth Cecelski
Energy, Environment & Development (EED)
Bahnstrasse 24
D-51688 Wipperfürth
Germany
Tel. +49 2267 82050
Fax +49 2267 880 762
Email <ececelski@t-online.de>

From krksmith at uclink4.berkeley.edu Thu Nov 12 05:46:07 1998
From: krksmith at uclink4.berkeley.edu (Kirk R. Smith)
Date: Tue Aug 31 21:36:10 2004
Subject: Wood stoves/GHG
In-Reply-To: <2.2.16.19981111172326.35d77f5a@pop.igc.org>
Message-ID: <3.0.1.32.19981112100107.0076f474@uclink4.berkeley.edu>

Greetings, Unfortunately, the GHG implications of biomass stoves are not
simple. We have just finished extensive monitoring of about 60 of the most
common fuel/stove combinations in India and China; measuring a number of
energy, mass, and emissions charactistics, including some 50 airborne
pollutants of interest from GHG and/or health standpoints. (We have also
done similar measurements of charcoal kilns in Thailand, Kenya, and Brazil.)

The bottom line is that biomass stoves are not by any means GHG neutral,
because they divert so much of the fuel carbon to products of incomplete
combustion (up to 20% in many dung and crop residue stoves; up to 10% or so
in wood stoves). Among these, methane is a powerful GHG, more than 20x
worse than CO2 on a molecular basis. As a result, counter-intuitively, in
many cases simple kerosene and LPG stoves are actually lower emitters of
GHG per meal, even though using fossil carbon. This depends on the
particular stove, however, because although biomass fuel types tend to
group together, there can be wide variation depending on the stove
combustion conditions.

Thus, for a biomass stove fuel cycle to be near GHG neutral not only must
the biomass be harvested renewably, but the combustion efficiency must
approach 100%, a condition met by very few traditional or "improved"
cookstoves in use today in LDCs.

One of the striking results of our work is that biogas stoves are by far
the best of any we measured from a GHG standpoint, having the double
advantage of being based on renewable supply (animal dung) and being burned
as a gas, with which it is easy to achieve high combustion efficiency. Of
course, its overall advantage will depend on methane leakage from the
digester and pipes as well, which we have not determined.

I have draft summaries of the India and Thai reports that could be posted
on a website. (If anyone has a website to offer, please contact me
privately to arrange.)

Cheers/Kirk R. Smith, UC Berkeley

At 02:23 PM 11/11/98 -0800, Cynthia Knowles wrote:
>To: Members of stoves and bioenergy lists
>Re: Request for information on link between wood stoves and GHG
>
>Do any list members have information or know of info. sources on wood
>burning stove emissions and their contribution to the overall concentration
>of greenhouse gases?
>
>Thank you in advance,
>Cynthia Knowles
> ******************************************
> Cynthia L. Knowles
> E-mail: cknowles@igc.apc.org
> Enersol Associates, Inc.
> A Member of
> The Global Transition Group
> 55 Middlesex Street, Suite 221
> North Chelmsford, MA 01863 USA
> Tel: (978)251-1828/29; Fax: (978)251-5291
>
>
>Stoves List SPONSORS and ARCHIVES:
>http://solstice.crest.org/renewables/stoves-list-archive/
>Stoves Webpage
>http://www.ikweb.com/enuff/public_html/Stoves.html
>For information about CHAMBERS STOVES
>http://www.ikweb.com/enuff/public_html/Chamber.htm
>
>
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From english at adan.kingston.net Thu Nov 12 07:37:28 1998
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:36:10 2004
Subject: Theoretical Yield of Charcoal
In-Reply-To: <364A86EB.C3731BF0@myhost.ccsinc.com>
Message-ID: <199811121249.HAA15452@adan.kingston.net>

Dear Charcoalers,

> kchishol wrote:
> >
> > Elk is getting in the order of 25% charcoal yield from his
> > sawdust charcoal operation. If the theoritically attainable
> > maximum yield was 26%, he is doing phenomenal. However, if
> > the theoretical maximum is 50%, then he has lotsa
> > opportunity for improvement.

5o% is achievable under pressure, as done by Dr. Michael Antal of
Hawaii.

Dan Gill wrote:
> I am one of the non-technical members so my figures are rule-of-thumb. I
> believe that 25% is good for a direct burn. From the figures I have
> seen, about 2/3 of the BTUs in wood are contained in the volatiles
> leaving 1/3 in the charcoal. Assuming a linear relationship of weight to
> BTUs the theoretical max yield is between 30-35% (dry basis) for most
> woody biomass.

If the charcoal contains 12000btus/lb. the a 25% mass yeild of
charcoal would contain a 37% energy yeild. Roughly speaking a 1/4
yeild by mass for a 1/3 yeild for energy. The pyrolysis volatiles
have less than half the btu/lb content of remaining charcoal.

Alex

From antal at wiliki.eng.hawaii.edu Thu Nov 12 12:46:39 1998
From: antal at wiliki.eng.hawaii.edu (Michael Antal)
Date: Tue Aug 31 21:36:10 2004
Subject: Theoretical Yield of Charcoal
In-Reply-To: <364A6413.59260B82@fox.nstn.ca>
Message-ID: <Pine.HPX.4.03.9811120755360.11201-100000@wiliki.eng.hawaii.edu>

Dear Kevin: the theoretical yield of charcoal from most biomass is on the
order of 40 to 60 wt%. The theoretical fixed carbon yield is about 30%.
These ideas, together with discussions of our high-yield charcoal
technology, are available in my publications. Earlier, I have offered to
send copies of these publications to anyone who requests them. Regards,
Michael Antal.

On Thu, 12 Nov 1998, kchishol wrote:

> Elk is getting in the order of 25% charcoal yield from his
> sawdust charcoal operation. If the theoritically attainable
> maximum yield was 26%, he is doing phenomenal. However, if
> the theoretical maximum is 50%, then he has lotsa
> opportunity for improvement.
>
> I would hypothesize that the maximum yield attainable in a
> real world operation would be from a charcoal retorting
> operation, running on bone dry sawdust. Would anyone have
> data on what yield could be expected in this case?
>
> The next question is a bit more difficult.: How can
> pyrolysis gases be processed to recover carbon?
> Specifically, the so-called "creosote" is a low grade form
> of "wood coke", in that it still has some volatiles present.
> The creosote or wood tar fraction is basically a complex
> C-O-H compound of some sort. If the -O-H elements could be
> removed, then there would be an additional yield of solid C.
> How can this be done? How much additional carbon yield could
> be attained, if this was possible?
>
> Kevin Chisholm
>
> Stoves List SPONSORS and ARCHIVES:
> http://solstice.crest.org/renewables/stoves-list-archive/
> Stoves Webpage
> http://www.ikweb.com/enuff/public_html/Stoves.html
> For information about CHAMBERS STOVES
> http://www.ikweb.com/enuff/public_html/Chamber.htm
>

From thomas_milne at nrel.gov Thu Nov 12 21:19:42 1998
From: thomas_milne at nrel.gov (Milne, Thomas)
Date: Tue Aug 31 21:36:10 2004
Subject: FW:
Message-ID: <199811130219.VAA09608@solstice.crest.org>

-----Original Message-----
From: Milne, Thomas
Sent: Friday, November 06, 1998 3:24 PM
To: 'bioenergy@crest.org'
Subject:

At long last, thanks to input from many of you, the "tar" survey is available.
It is about 200 pages long and can be transmitted by e-mail. (Contact Tom
Milne, milnet@nrel.gov. <mailto:milnet@nrel.gov.> ) A limited number of hard
copies are also available. Eventually it will be displayed on the NREL
Biomass
Power Home Page.

The title is: Biomass Gasifier "Tars": Their Nature, Formation and
Conversion.
NREL/TP-570-25357, November 1998. By: T.A. Milne, N. Abatzoglou. and R.J.
Evans. This report was prepared at the request of Suresh Babu and the IEA
Biomass Utilization Task XIII, "Thermal Gasification of Biomass" activity.

Tom Milne, Principal Chemist, emeritus.
National Renewable Energy Laboratory
1617 Cole Blvd.
Golden, Colorado.

From tmiles at teleport.com Thu Nov 12 22:29:11 1998
From: tmiles at teleport.com (Tom Miles)
Date: Tue Aug 31 21:36:10 2004
Subject: Sponsor the Stoves List
Message-ID: <199811130341.TAA27341@mail.easystreet.com>

We need sponsors for the Stoves List.

This month the Stoves List is provided courtesy of:

FAO-RWEDP, Auke Koopman

Sponsorship costs $50 per month. We ask for a minimum of three months.

The list receives no other funding so contribute to keep the discussion
rolling.

To sponsor Stoves, or one of the other lists, please fill out the form at:

http://crest.org/services/biolist-spons.shtml

and send a check to CREST as instructed.

Thanks

Tom Miles
Bioenergy Lists Administrator
T.R. Miles tmiles@teleport.com
1470 SW Woodward Way http://www.teleport.com/~tmiles
Portland, OR 97225
Tel 503-292-0107 Fax 503-605-0208
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From larcon at sni.net Fri Nov 13 07:17:43 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:10 2004
Subject: Forwarding: Publication offer from Tom Milne
Message-ID: <v01540b01b271d6de6f82@[204.131.233.27]>

Tom said:

>At long last, thanks to input from many of you, the "tar" survey is available.
>It is about 200 pages long and can be transmitted by e-mail. (Contact Tom
>Milne, milnet@nrel.gov. <mailto:milnet@nrel.gov.> ) A limited number of hard
>copies are also available. Eventually it will be displayed on the NREL Biomass
>Power Home Page.
>
>The title is: Biomass Gasifier "Tars": Their Nature, Formation and
>Conversion.
>NREL/TP-570-25357, November 1998. By: T.A. Milne, N. Abatzoglou. and R.J.
>Evans. This report was prepared at the request of Suresh Babu and the IEA
>Biomass Utilization Task XIII, "Thermal Gasification of Biomass" activity.
>
>Tom Milne, Principal Chemist, emeritus.
>National Renewable Energy Laboratory
>1617 Cole Blvd.
>Golden, Colorado.
>

From larcon at sni.net Sat Nov 14 18:24:12 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:10 2004
Subject: Forwarding: A request for data
Message-ID: <v01540b02b273b8a7dfa7@[204.131.233.27]>

Stovers: The following in from jahmal bahdon. I do not recall a specific
discussion on this list of the range of data that is found in practice.
Anyone able to suggest some leads for Jamal? I hope you can respond for
the full group.

Jamal - Please let me know if I should sign you up for the "stoves" list.
There are many persons on the list with expertise for specific stoves in
particular countries. And several on the list are doing worldwide
comparisons - but I am not sure whether they are ready to release that data
yet. (See a message also on Thursday from Kirk Smith, who mentions his own
tests on 60 stoves.) There are many articles in older journals on the
topic. Also see the journal "Boiling Point".

It will help our members to know more about the reasons for your
request. Good luck in your endeavors, and I hope you will let us know what
you learn. Ron

Ron

>Dear Colleagues;
>
>I am doing research on woodfuel (fuelwood+charcoal)consumption in the
>developing countries. I am particularly interested in survey-based per
>capita consumption data.
>
>Accordingly, I would appreciate if your organization has any I would
>appreciate if you share with me.
>
>
>Thanks in Advance
>
>Regards
>
>JB "jamal bahdon" <jbahdon@hotmail.com>

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From kammen at Princeton.EDU Sun Nov 15 08:28:54 1998
From: kammen at Princeton.EDU (Daniel Kammen)
Date: Tue Aug 31 21:36:10 2004
Subject: woodfuel (fuelwood+charcoal)consumption
Message-ID: <l03110702b2748a6ba751@[128.112.70.33]>

Jamal,
There is a fair amount written on the topic of wood and charcoal use; both
individual
country studies (such as Kenya, Tanzania, Zambia, Mexico) and estimates of
total
global use. Estimates range to over one ton (biomass) per person per year
in some
locations, and of course down to very little in areas where fuel
alternatives are available.

I am forwarding a report on charcoal production and use that summarizes
some of what you are after.

- dan kammen

_________________________________________________________________

Daniel M. Kammen
Assistant Professor of Public and International Affairs
Chair, Science, Technology & Environmental Policy (STEP) Program
201 Five Ivy Lane
Woodrow Wilson School of Public and International Affairs
Princeton University
Princeton, NJ 08544-1013

Tel: 609-258-2758 Fax: 609-258-6082, or 2394
Email: kammen@princeton.edu
WWW: http://www.wws.princeton.edu/~kammen/
Secretary Jackie Schatz: Tel: 609-258-4821
Email: jackie@wws.princeton.edu
__________________________________________________________________

From dstill at epud.org Thu Nov 19 18:20:19 1998
From: dstill at epud.org (Dean Still)
Date: Tue Aug 31 21:36:10 2004
Subject: looking for Todd Harris
Message-ID: <199811192330.PAA00493@seahorse.epud.net>

Aprovecho is looking for Todd Harris - he is a stove maker in Nairobi. If
anyone has his e-mail or snail mail address could you forward it to
apro@efn.org

From english at adan.kingston.net Mon Nov 23 07:54:02 1998
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:36:10 2004
Subject: Webpage update
Message-ID: <199811231307.IAA13737@adan.kingston.net>

Dear Stovers,
Two summary reports about greenhouse gas emissions from wood stoves
and charcoal kilns can be linked to from the Stoves webpage.
Alex
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From larcon at sni.net Mon Nov 23 21:55:28 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:10 2004
Subject: New member introduction: Kjell-Ove Martinsson
Message-ID: <v01540b03b27fce63e6ad@[204.131.233.7]>

Stovers: Following my usual short welcome message to new list member
Kjell, I received the following reply which I think all will find an
interesting and different introduction.

Kjell: I may have overemphasized the words "third-world". I am trying to
screen out the many questions on how to find spare parts or hw to sell
antique wood stoves. Your interests here are exactly on target and any
progress you might make in using pyrolysis gases is certainly potentially
appropriate in developing countries. We wish you luck and again welcome to
the list. Be sure to see the web page run by Alex English that may give
you some valuable ideas:

(Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html

I am not sure how to design what you are after, but perhaps others
will give you some other thoughts for your ambitious project. good luck.
Ron

>Well, I did not realize this mailing list is mostly about third-world
>technology. My interest in wood stoves stems from the fact that I live in
>the country and I want to get most of the energy I use from biomass and solar.
>
>The most immediate concern I have is how to make a flue gas condenser for a
>kitchen stove. I want to be able to cook and bake and at the same time
>produce and store hot water for heating my house.
>
>Another idea or fantasy is the UWEM (Universal Wood Energy Machine). In
>this contraption I first want an effective and environmentally benign
>pyrolizing and burning of biomass. The hot gasses will then be canalized
>to one of several uses:
>
>1. The boiler, to make steam for a steam engine or for process purposes.
>2. The baking oven.
>3. The cooking unit.
>4. Directly to the condenser for making hot water.
>
>Will these questions be relevant to the stoves list or should i seek
>another forum?
>
>Kjell-Ove Martinsson

kjellove@mail.nsb.norrkoping.se

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From larcon at sni.net Mon Nov 23 21:55:40 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:10 2004
Subject: Forwarding a request on chulo stoes
Message-ID: <v01540b05b27fd1fbbee9@[204.131.233.7]>

Stovers: The following is relatively self-explanatory. Can anyone provide
specific help? Ron

>
>I'm wondering whether anyone has any information concerning the cultural
>implications, success rate or deployment strategies of installing
>smokeless chulo stoves in rural areas of South Asia, particularly Nepal.
>I'm conducting research for an NGO called Educate the Children which
>promotes women's and children's health, education and empowerment.
>One of their projects is to reduce the rate of respiratory illnesses and
>burns that result from open tripod stoves by installing chulos but are
>concerned about what the best method to do this would be.
>I'de appreciate any suggestions for possible sources of information.
>
>Thanks,
>Maya Katz mk86@cornell.edu
>

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From elk at net2000ke.com Tue Nov 24 07:43:01 1998
From: elk at net2000ke.com (e. karstad)
Date: Tue Aug 31 21:36:10 2004
Subject: The Fusion Stove
Message-ID: <v01510102b28055690fae@[195.202.65.83]>

The first and third world are meeting- in some respects anyway.

A commonly heard complaint about charcoal (particularly my clay-bound
salvaged vendors waste charcoal briquettes) & charcoal stoves heard around
Nairobithese days is that they aren't fast enough. They take too long to
get up to a good cooking heat. That quick 'cuppa' is best brewed on a gas
or kerosene stove while you are hurredly throwing on your work clothes
prior to dashing out the door- late as usual.

So... First-world time constraints are being felt over here in East Africa.
First and Third worlds are growing closer- at least in some respects.

This has led me to develop a stove that meets the time constraints of the
modern Nairobian- at this point I don't know if it's merely a novelty item
or if it truly has a place in the modern hut..... it's been fun to make and
even more enjoyable to use...

I've taken an improved Kenya Ceramic Jiko - one of those squat hourglass
shaped charcoal stoves with a ceramic insert- and attached a 12 volt DC
'biscuit' fan into it's side in the lower half of the stove below the clay
insert. As most of you are currently viewing this on normal PC's- it's the
fan that cools the power supply unit at the back of your computor. Take a
look.... Four inches in diameter and surprisingly qiet and powerful.

I place the charcoal on a shallow bed of dry twigs and light a match to a
crumpled piece of newspaper in the bottom of the stove. Once the paper is
burning I close the door and turn on the fan (powered by a small 12 V DC
rechargeable gell-cell). WHOOSH! There's more flame and heat than I'd
expect from a liberal dosing of gasoline.

In 2 minutes the briquettes are ready to cook on; the charcoal is glowing
brightly. The fan can be turned off now and an air tight door slid over the
opening.- or left on for (I expect) a rather innefficient but very hot
charcoal fire more suitable as a blacksmith's forge than a cookstove.

Two minutes. It takes 15 minutes and some manual fanning to reach full heat
without the fan in the same 30 cm dia. stove. The fan provides a reduction
in ignition time for this stove (using my 'slow' briquettes) to 13% of
normal.

If there's any interest I can send Alex a photo or two for the web-page.

elk

~~~~~~~~~~~~~~~~~~~~:
E.L. Karstad :
P.O. Box 24371 :
Nairobi, Kenya :
Fax/tel 884437 :
elk@net2000ke.com :
~~~~~~~~~~~~~~~~~~~~'

From larcon at sni.net Wed Nov 25 18:27:26 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:10 2004
Subject: Forwarding: Request on chip heater
Message-ID: <v01540b00b281efce88bb@[204.131.233.44]>

Stovers: This message is asking for help on a particular stove type. I
believe the questioner is now living in the US state of Georgia.

Paul (or anyone): What made this stove particularly attractive?
Approximately what depth of chips as used, etc?

>To: owner-stoves@crest.org
>Subject: chip heater
>
>I have been looking for information on chip heaters and came across your
>page. We used chip heaters in Papua New Guinea when I was growing up.
>As far as I know, they were made in Australia. I would like to obtain
>one, if you have any information you could pass on to me.
>
>Sincerely, Paul Frantz
> paul_&_ellen_frantz@ima.connections.com
>

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From larcon at sni.net Wed Nov 25 18:27:35 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:10 2004
Subject: Forward: Request for stoves help for Ghana
Message-ID: <v01540b02b281f4a7ac32@[204.131.233.44]>

Stovers. Please read this in four chronological parts over the last
several days.

A. Original message yesterday:

>>To whom it may concern,
>>
>>I am looking for information about the use of methane as a source of
>>cooking-energy in villages of West Africa. Can you direct me?
>>Greetings from frozen Germany.
>>Marion <marion.jackson@uni-tuebingen.de>

>>org: Physiologische Oekologie der Pflanzen

B. I replied yesterday:

>> Marion - I need more information before sending your request on to the
>> stoves list. Our list is primarily interested in simple cook stoves for
>> developing countries - but generally restricted to biomass input. If you
>> are interested in biodigestion to produce the methane, you should probably
>> be contacting a "sister" list also under "crest". If the interest is just
>> in the details of cooking with natural gas which is mostly methane, I don't
>> think we are the right list. But if you are interested in low purity
>> methane and very low cost approaches to the burner only, maybe we on the
>> "stoves" list should discuss this topic. Please let me know a little more
>> on the topic you wish to discuss. Ron
>>

C. Today, I heard back as follows:

>Dear Ron,
>
>sorry to know so little about the topic.
>Mainly I`m interested in both. I'd like to collect information to introduce in
>Ghana, and see, which suit their purpose. The reason why I am
>interested in biodigested methane is, because most people do not possess
>>toilets there, and so they have plenty of "bio-material" in streets and
>places. >But simple stoves may be all they can afford.
>Thanks for your fast reply Marion

D. (from Ron:) Stovers:
This now seems to be an open ended question on how to help Ghanians
with a current cooking problem. So I hope others can jump in to offer
additional ways to help Marion and Ghana, perhaps along the line of what
follows. I think the names of stoves people who are already working in
Ghana will be most helpful.

E. Marion: I am signing you up for "stoves" so that you can participate
more easily in our discussions. Feel free to drop off whenever ready.
Please first look at two other stoves locations to get more background for
making decisions about the best stoves for Ghana:

Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/

Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html

I happened to have met last week with a group of Ghanians, who were
visiting Denver as part of a small business development program. One
person was a Policy Analyst the Ministry of Environment, Science, and
Technology: Mr. Francis Joojo Djamson <Barnes@Africaonline.com.gh>.
Francis expressed considerable interest in the "stoves" list and promised
to pass our capabilities to a suitable person in Ghana's

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From larcon at sni.net Thu Nov 26 13:22:07 1998
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:10 2004
Subject: Forwarding: Request on chip heater
Message-ID: <v01540b01b283481af5a1@[204.131.233.10]>

Stovers: The following information in from Paul Frantz. I now understand
that this was a water heater (also for space heat?), so I am more
interested in the technology - as I think that such water heating is a
valuable way to increase the efficiency of cook stoves (which I gather this
was not). Does this further information provide any more clues for our
(especially Australian) colleagues to help out?
Paul - I am afraid I have nothing further to help. I would think
the interesting questions are:
1) What was the approximate volume of water, if the total outer can
had a volume of 20 liters.
2) Was this a single coil of pipe (and what length?) inside, or
was there an outer "sleeve" (and what spacing?)?

Paul - Pleae keep us informed if you get more data. Ron

> Ronal, As far as I remember, it was about the size of a
> 20 gallon drum. On the top surface it had a place for a
> smoke stack [approx. 4" ] and a funnel to put water in it.
> There was also a hole to put the chips (or paper as the
> case may be) in to burn. There was a removable tray at the
> bottom of the drum to catch ashes. The spout where the hot
> water came out was located about 2" below the upper rim of
> the drum on the opposite side of the drum from the funnel.
>
> The attractiveness of it lies in its efficiency and ease of
> operation. One small handful of kindling would heat 15-20
> gallons of almost boiling water as fast as you could pour
> it in.
>
> Do you have any information on where to obtain something
> similar?
>
> Thanks for the reply, Paul
>
>
>
>
>______________________________ Reply Separator
>_________________________________
>Subject: Forwarding: Request on chip heater
>Author: <larcon@sni.net (Ronal W. Larson)> at INTERNET
>Date: 11/25/98 05:44 PM
>
>
>Stovers: This message is asking for help on a particular stove type. I
>believe the questioner is now living in the US state of Georgia.
>
>Paul (or anyone): What made this stove particularly attractive?
>Approximately what depth of chips as used, etc?
>
>>To: owner-stoves@crest.org
>>Subject: chip heater
>>
>>I have been looking for information on chip heaters and came across your
>>page. We used chip heaters in Papua New Guinea when I was growing up.
>>As far as I know, they were made in Australia. I would like to obtain
>>one, if you have any information you could pass on to me.
>>
>>Sincerely, Paul Frantz
>> paul_&_ellen_frantz@ima.connections.com
>>
>
>Ronal W. Larson, PhD
>21547 Mountsfield Dr.
>Golden, CO 80401, USA
>303/526-9629; FAX same with warning
>larcon@sni.net
>
>
>
>

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From english at adan.kingston.net Sat Nov 28 22:50:05 1998
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:36:10 2004
Subject: Webpage update
Message-ID: <199811290403.XAA14489@adan.kingston.net>

Dear Stovers,
Krishna Prasad of the Eindhoven University of Technology has sent me
a lot of documents about stoves. Most of them are a product of the
Woodburning Stove Group at Eindhoven. The first piece that I have
put on the webpage (Check the Stoves Webpage New section) is about a
downdraft stove which they found to be by far the best of any they
worked with, in term of combustion quality. This paper, from 1991,
provides a good overview of wood combustion, and of the challenges of
developing a naturally drafted cooking stove with acceptable low
emissions.

I hope to post additional portions of these documents as time allows.

Alex

From mheat at mha-net.org Mon Nov 30 13:19:49 1998
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:36:10 2004
Subject: good paper
Message-ID: <4.1.19981130131728.00a6f100@mha-net.org>

hi John;

Further to our conversation the other day, you might want to download the
new paper on Alex's site, "Clean
Combuston of Wood by A.M. Hasan and R Khan
(1991)"

-- it is a wonderful example of good basic research based on a
well-thought out plan and with documented, simple protocols. As a matter
of fact, chimney height was the main parameter studied, with interesting
results in this particular application. An 02 meter and CO meter were the
only high tech equipment required, such as you would get with a TESTO
(CO2 can be calculated from O2 for a given fuel).

I could go into the shop today and try to duplicate their results, which
is a good indicator of the completeness of the description of the
protocol. Furthermore, the results are clear enough, and the analysis is
broad based enough that I can apply the findings in designing testing in
other areas.

This paper is well worthy of study by anyone planning to design and
engage in a stove testing program.

Best.......Norbert
----------------------------------------
Norbert Senf---------- mheat@mha-net.org
Masonry Stove Builders
RR 5, Shawville-------
www.mha-net.org/msb
Quebec J0X 2Y0-------- fax:-----819.647.6082
---------------------- voice:---819.647.5092

From REEDTB at compuserve.com Mon Nov 30 14:37:35 1998
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:36:10 2004
Subject: Theoretical Yield of Charcoal
Message-ID: <199811301450_MC2-61FD-1249@compuserve.com>

Dear All:

There is no "theoretical" yield of charcoal (in spite of what Mike Antal
says). I prefer to think of it as XCOAL where X is the degree of
devolatilization or volatile cracking. Normal charcoaling at 450C produces
typically 25% charcoal with 20% volatiles, the typical yield also in our
inverted downdraft gasifier. Larger pieces can crack more volatilve for
higher yields. Chemical treatment (ZnCl2 and Na2CO3) can increase yield.
High pressure can produce up to 50% in Antal's process. But if you don't
measure the volatile and energy content you don't know how charcoally it
is. Get a prox-ult analysis.

Higher temperatures can produce much smaller yields like 15% for
metallurgical charcoal (600C) or 10% for activated charcoal (800C).

So the original question is meaningless without a lot more specification.

Yours, TOM
REED

Message text written by kchishol
>
Elk is getting in the order of 25% charcoal yield from his
sawdust charcoal operation. If the theoritically attainable
maximum yield was 26%, he is doing phenomenal. However, if
the theoretical maximum is 50%, then he has lotsa
opportunity for improvement.

Kevin Chisholm
<

From kchishol at fox.nstn.ca Mon Nov 30 18:11:54 1998
From: kchishol at fox.nstn.ca (Kevin Chisholm)
Date: Tue Aug 31 21:36:10 2004
Subject: Theoretical Yield of Charcoal
In-Reply-To: <199811301450_MC2-61FD-1249@compuserve.com>
Message-ID: <E0zkcgq-0001Fp-00@mail1.halifax.istar.net>

> Date: Mon, 30 Nov 1998 14:50:13 -0500
> From: Tom Reed <REEDTB@compuserve.com>
> Subject: Theoretical Yield of Charcoal
> To: kchishol <kchishol@fox.nstn.ca>, Stoves <stoves@crest.org>,
> gasifiers <gasification@crest.org>

Dear Tom

Thank you very much for your clarifying comments.

What I was getting at was a target or standard which Elk could
reasonably achieve in his downdraft sawdust charcoaling stove. In his
last report he indicates a yield of 23% of feed sawdust. On the
assumption that his charcoal is 20% volatiles, then he is doing very
close to what you feel is the maximum attainable for downdraft
atmospheric charcoaling operations.

I wonder if there is anyone employing different charcoaling making
technology, who would be able to report on what their technology
yields as a typical charcoal yield, and what would be its typical
volatiles content? More particularily, would anyone have results for
charcoaling using atmospheric pressure retorts, externally heated?

Your comments are most helpful, in that they indicate that Elk is
getting about as much yield as he can reasonably expect. It is also a
confirmation that Elk is not doing very much which is wrong!! :-)

Kevin Chisholm

> Dear All:
>
> There is no "theoretical" yield of charcoal (in spite of what Mike Antal
> says). I prefer to think of it as XCOAL where X is the degree of
> devolatilization or volatile cracking. Normal charcoaling at 450C produces
> typically 25% charcoal with 20% volatiles, the typical yield also in our
> inverted downdraft gasifier. Larger pieces can crack more volatilve for
> higher yields. Chemical treatment (ZnCl2 and Na2CO3) can increase yield.
> High pressure can produce up to 50% in Antal's process. But if you don't
> measure the volatile and energy content you don't know how charcoally it
> is. Get a prox-ult analysis.
>
> Higher temperatures can produce much smaller yields like 15% for
> metallurgical charcoal (600C) or 10% for activated charcoal (800C).
>
> So the original question is meaningless without a lot more specification.
>
> Yours, TOM
> REED
>
> Message text written by kchishol
> >
> Elk is getting in the order of 25% charcoal yield from his
> sawdust charcoal operation. If the theoritically attainable
> maximum yield was 26%, he is doing phenomenal. However, if
> the theoretical maximum is 50%, then he has lotsa
> opportunity for improvement.
>
> I would hypothesize that the maximum yield attainable in a
> real world operation would be from a charcoal retorting
> operation, running on bone dry sawdust. Would anyone have
> data on what yield could be expected in this case?
....del...
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BioEnergy Lists: Improved Biomass Cooking Stoves

November 1998 Biomass Cooking Stoves Archive