December 1997 Gasification Archive

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

From CAMPBELLDB at cdm.com Mon Dec 1 11:05:03 1997
From: CAMPBELLDB at cdm.com (Dan Campbell)
Date: Tue Aug 31 21:35:45 2004
Subject: Fwd: kerosene stoves
Message-ID: <9712011604.AA14077@cdm.com>

Dear Stovers:

If anyone can send info to Tony Golding about alternative designs for Wick
Stoves, please do so. His email is: tony@mepta.pwv.gov.za. I would appreciate
a copy of any responses to Tony for my own records.

Regards,
Dan Campbellm EHP
email: campbelldb@cdm.com
URL: www.access.digex.net/~ehp

To: campbelldb@cdm.com
Subject: kerosene stoves
From: "GOLDING TONY" <tony@mepta.pwv.gov.za>
Date: 01 Dec 97 15:57:24

Dear Dan

I was most interested to receive the ARI Network Update # 7 and read
various remarks on kerosene, which is "flavour of the moment" (ugh!)
so to speak in South Africa after a US Dept of Energy report on
lethal CO levels in wick stove using households. The comments by
Skip Hayden were what we have been suspecting. Were his findings
from experience or based on any report/document?

I would also be interested to know from Prof Kirk Smith as to the
design of the Chinese model refered to - as the local wick stove here
is of Chinese origin.

Is there any information about alternative WICK stoves of decent
quality and good design?

Clearly if the 'Energy Ladder' concept is accepted, then any
interventions aimed at improving on biomass use beyond the
improvement of wood stoves eg. kerosene or LPG, has to consider not
just the fuel itself (and there are many different grades of
kerosene) but the appliance. A good appliance, if used with good
kerosene, would be a viable (healthy) alternative to a woodstove. But
higher standards need to be enforced in developing countries for this
to happen.

Best regards

Tony Golding
Tony Golding
Energy for Development
Dept Mineral and Energy Affairs
Private Bag X59, Pretoria 0001, South Africa
tel: 012 317 9223 Int. +2712 317 9223
fax: 012 322 5224 Int. +2712 322 5224

From renee.sossong at mailcity.com Mon Dec 1 13:56:49 1997
From: renee.sossong at mailcity.com (Paul & Renee Sossong)
Date: Tue Aug 31 21:35:45 2004
Subject: Blower motor replacement
Message-ID: <347DC267.394@mailcity.com>

I have an older Buck stove that I believe needs a motor. It was made in
1978, or so, and I need to find out how to get a motor and how much is
it. It is a large insert similar to a current model 21 and 51. I live in
Great Mills, MD. My phone is 301-862-1572. Email is
SOSSONG@mail.ameritel.net

From larcon at sni.net Mon Dec 1 18:53:52 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:45 2004
Subject: Explaining the glitch and Two Non-member submissions
Message-ID: <v01540b01b0a440cd5cd3@[204.133.251.24]>

Stovers:

This is to explain 1) the last major glitch and 2) ask for some help and 3)
pass on a request for explanation,

1. Eric Ferguson dropped from the list, saying

>For the second time in two months one of the CREST mailing list has spammed
>my e-mail with the useless product of an endless "Bounce" loop.

>I have now decised to unsubscribe from all CREST lists, and will not return
>until I receive a firm assurance that such events are no longer possible.

RWL:
I apologize for the failure, which was in part my fault, as I thought we
agreed to have the following types of messages come through uninhindered.
In this case, a computer for one of list members in Canada got into an
endless loop with the CREST computer. I only got 70 some messages before
calling Zach Nobel at CREST, who solved the problem by cutting off the
offending computer (and a few others which couldn't handle the size of the
stove-digests that somehow picked up the "BOUNCE" messages) and then Zach
rearranged our list configuration to stop at least that kind of problem. I
am sure that we will find some other glitch down the road, and so Eric, I
am unable to provide any "firm assurance", although I think our chances are
better now.
At least this time, we only got dozens, not thousands of messages,
and I presume most of you got many fewer than dozens.

2. On a Buck Stove:
I don't know whether anyone on this wishes to help, but I am pretty
sure this first kind of "newly blocked" message can only be of interest to
a few. In the future, I would like to send a reply to these inquiries that
says we are the wrong list (and not send these to the full list), but I'd
be glad to send along the names of anyone on this list who might want to
try to help,

Anyone have a suggestion of where to send this first such request
or what to do?
To "Sossong": This list is primarily devoted to discussing low
cost alternatives to the most primitive third-world cook stoves and their
efficiency and health consequences. You are welcome to join, but we are
probably not the right group. Sorry.

>From "Sossong":
>I have an older Buck stove that I believe needs a motor. It was made in
>1978, or so, and I need to find out how to get a motor and how much is
>it. It is a large insert similar to a current model 21 and 51. I live in
>Great Mills, MD. My phone is 301-862-1572. Email is
>SOSSONG@mail.ameritel.net
>

3. RWL: The following from "jupni" <jupni@kirti.cso.ui.ac.id> is of more
interest and I encourage "jupni" to apply for list membership (reply to
larcon@sni.net). See my own responses after your questions:

>I'd like to learn more about organic waste pyrolisis. Would you please
>explain about:
>What kind of materials can be pyrolized by your 3CAN STOVE?

Certainly wood of diameter 1-4 cm diameter. Larger may be
problematic due to not having enough surface area; smaller because of too
much. I don't believe the limits have yet been established. We have been
talking here of sawdust, and that will certainly not be possible. Some of
us have tried pellets of roughly 1/2 cm diameter and these did not work
well. I tried using dung once and had no success - I'm not sure why, but
possibly the density was not high enough. I am responding above to more
than the term "3can" - rather all pyrolyzing stoves that we have been
discussing,

Follow this list's conversations on pyrolyzing sawdust raised by
Elsen Karstad and you will probably be moving in the right direction.

The alternative is to consider digestion. What scale are you
considering and what is your waste material?

>What gases produced by that pyrolisis?

The dominant gas is CO, with variable but smaller amounts of CH4
and H2 and then hundreds of other tars and chemicals. Undesired is CO2 and
N2 (not yet measured to my knowledge) before we add secondary air and then
combust - after which almost everything is these latter two gases and
perhaps 10% O2 from excess air addition. We seem to be getting CO levels
after combustion less than 1000 ppm, and perhaps much better, but not yet
sure.

>What is the conversion/yield?

We have been reporting charcoal yields from about 19% to 25%.

>I really appreciate your attention and helpful information.

We look forward to hearing more about your own interest in pyrolysis.

Regards 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 Thu Dec 4 06:27:43 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:45 2004
Subject: Non-member submission from ["Forest awareness" <forestaware@iwwn.com.na>]
Message-ID: <v01540b00b0ac465348e3@[204.133.251.26]>

Stovers: again another interesting new request, Ron

>From: "Forest awareness" <forestaware@iwwn.com.na>
>To: <stoves@crest.org>
>Subject: Fuel saving stoves
>Date: Thu, 4 Dec 1997 08:17:10 +0200

>
>Hello out there!
>
>I am working on a socalled Forest Awareness and Tree Planting Project in
>the northern Namibia, Owamboland. 90% of people cooks on three stones over
>open fire. We are trying to promote the use of stoves, but the type we can
>get here is of poor quality, and are burned out after 3 months. This
>prevents people to buy them.
>Can you help me to get some drawings of how to make stoves of either iron,
>cement or clay.
>
>Hope to hear from you soon.
>
>
>Regards Lars Moller

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

From btremeer at dds.nl Sun Dec 14 04:44:21 1997
From: btremeer at dds.nl (Grant Ballard-Tremeer)
Date: Tue Aug 31 21:35:46 2004
Subject: Resources on the WWW
Message-ID: <01BD0874.FD56E1C0.btremeer@dds.nl>

>From Grant Ballard-Tremeer btremeer@dds.nl
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Greetings Stovers,

I'm finally able to announce that the full text of my thesis on the
'Emissions of Wood-burning Cooking Devices' is available on my homepage.
If anyone would like to access it, the address is
http://www.ilink.co.za/~grantt. Please email me with comments, questions,
or any points you would like to discuss and I'll do my best to respond. I
hope to add other articles and relevant material regularly.

With best wishes
Grant

Detailed Table of Contents of material available at
http://www.ilink.co.za/~grantt

1 Overview
1.1 The extent of the problem
1.1.1 The health impact of combustion emissions
1.1.2 World-wide exposure to biofuel combustion products
1.1.3 Lack of alternatives
1.2 The gap in stove testing methods
1.2.1 The need for stove emission measurement
1.2.2 The difficulty of measuring emissions from stoves used by the rural
poor
1.2.3 Historic focus on efficiency not emissions
1.2.4 The existing methods of emission measurement
1.2.5 Issues considered in this study
1.3 Summary
1.4 Thesis organisation

2 Apparatus
2.1 Extraction booth
2.2 Extraction control
2.3 Orifice flow meter
2.4 Obscuration meters
2.5 Gas analysis
2.6 Weighing platform
2.6.1 Separation of wood and char
2.6.2 Measurement of fuel burn rate and water evaporated
2.7 Water temperature
2.8 Fire temperature
2.9 Data acquisition
2.10 Summary

3 The effect of an extraction hood
3.1 Background and aims
3.2 Experimental design
3.2.1 Variables and hypotheses
3.2.2 Levels
3.2.3 Significance
3.2.4 Treatment combinations, repetition and randomisation
3.2.5 Other variables
3.3 Results and discussion
3.3.1 Fire temperature, power and efficiency
3.3.2 Emissions
3.4 Summary and conclusions

4 The screening of experimental variables
4.1 Background and aims
4.1.1 Stove type
4.1.2 Amount of water
4.1.3 Pot lids
4.1.4 Wood type
4.1.5 Wood size
4.2 Experimental design
4.2.1 Variables and hypotheses
4.2.2 Levels
4.2.3 Significance
4.2.4 Treatment combinations, repetition and randomisation
4.2.5 Other variables
4.3 Results and discussion
4.3.1 Stove type
4.3.2 Amount of water
4.3.3 Pot lids
4.3.4 Wood type
4.3.5 Wood size
4.3.6 First order interactions
4.4 Summary and conclusions

5 Real-time emission patterns
5.1 Background and aims
5.1.1 The definition of the problem and the method of solution
5.1.2 Previous studies
5.2 Experimental design
5.3 Results and discussion
5.3.1 The open fires
5.3.2 The enclosed stoves
5.3.3 Extraction analysis of variance
5.3.4 Variable screening analysis of variance
5.4 Summary and conclusions

6 The simulation of a dilution chamber
6.1 Background and aims
6.2 Experimental design
6.3 Results and discussion
6.3.1 The effect of cooking task on chamber method accuracy
6.3.2 The effect of air exchange rate on chamber method accuracy
6.3.3 The effect of cooking device type on chamber method accuracy
6.4 Summary and conclusions

7 Summary and conclusions
7.1 The need for this work
7.2 The aim of this work
7.3 The approach
7.4 The effect of the extraction hood on emission measurements
7.5 The study of the effect of five experimental variables
7.6 The relationship between CO, SO2 and TSP
7.7 The validity of assuming constant emission rate in chamber tests
7.8 The significance of this work
7.9 Areas for further work

Appendix A Experimental results
A.1 Included on the diskette
A.2 Installing and removing the program
A.3 What the analysis program does
A.3.1 Emissions
A.3.2 Efficiency
A.3.3 Smoke and specific optical density and TSP

Appendix B Requirements of a testing method
B.1 International standards versus testing guidelines
B.2 Absolute versus comparative measurements
B.3 Integral versus real time measurements
B.4 Indirect versus direct measurements
B.5 Water boiling test versus other methodologies
B.6 Recommendations

Appendix C Factorial analysis
C.1 Identifying variables and defining hypotheses
C.2 Selection of levels
C.3 Level of significance
C.4 Treatment combinations, repetition and randomisation
C.5 Calculation methods

Appendix D Wood combustion
D.1 Oxidant
D.2 Fuel
D.2.1 Moisture
D.2.2 Inorganic Materials (Ash)
D.2.3 Organic Materials
D.2.4 Direct combustion
D.3 Pyrolysis
D.3.1 Ratio of volatiles to char
D.3.2 Initiation reactions
D.3.3 Pyrolysis reactions
D.3.4 Volatiles
D.3.5 Char
D.4 Combustion
D.4.1 Reaction Rate
D.4.2 Combustion of Activated Carbon
D.4.3 Combustion of Volatiles
D.4.4 Sulphur Dioxide

Appendix E Case study: cooking devices compared

References

From REEDTB at compuserve.com Sun Dec 14 08:11:49 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:46 2004
Subject: converting sawdust to charcoal briquettes
Message-ID: <199712140758_MC2-2BDB-BC3B@compuserve.com>

Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
Colorado School of Mines & The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Andrew Heggie (and stovers):

I have been sitting on your "summary" letter (below) for a few weeks
because it deserves a good answer.

Your summary (to Ferguson) pretty well "sums" up the present state of the
art - much progress being made using inverted downdraft stoves for cooking.
Progress also in charcoal making. Many new ideas being tested "out back".

Unfortunately, my outback has turned quite cold, so I sit here at the
computer listening to those in warmer climates or with heated labs.
However, I am planning a MAJOR campaign for Spring - after publishing
Volume I - to move my understanding of these issues forward and, I hope
give needed understanding and data in this critical field.

Here is a challenge: The inverted downdraft stoves currently produce good
cooking AND charcoal. If you need both how lucky! If you just want
cooking, the air velocity needs to be increased about 20fold to accomplish
gasification of the charcoal as well. In that case, the cross section area
will DECREASE 20fold and you will have a one inch diameter gasifier for a
2.5 kW equivalent stove. That is where I started my thinking in 1985.

How else can you consume the charcoal at the same rate as the wood?

Onward, TOM REED

~~~~

Summary Eric queried why we talk of charcoal making stoves
At 17:01 11/11/97,dr. E.T. Ferguson wrote:
>Dear Stovers,
>
>On this list there is a lot of discussion on the of ways producing
charcoal
>as a by- or co-product of a wood- or sawdust stove.
>
>I missed the beginning of this discussion. Can those who propose this
>please explain why this is a good topic to research? In my view a stove -

>to be economical - should adapt its heat output to the food being cooked.
>When producing charcoal, stove will need to adapt to the efficiency of
>charcoal production. It seems unlikely the two purposes will match.

Andrew Heggie:I will have a try at this, I wondered what it was about when
I
searched the list for information on charcoal making, hence I came in from
the opposite angle.
As I understand the history of this: in researching the possibility of
producing a smokeless biomas cookstove for under developed areas Ronal
Larson and Tom Reed decided to light a fire on top of the fuel, whilst
still
drawing primary air up through the charge, to burn the pyrolisis gases
secondary air entered above the fuel and was burned in a combustion area
above the charge, This design lent itself to construction from two cans
with
the secondary air gap between. It also led to complete combustion of the
pyrolisis gases which had not been possible in a fire lit at the botom (an
updraft fire) Reed/Larson named this inverted downdraft burning. This
twocan
principle of IDD burning is being developed by ELK and Alex English amongst
others.

A side effect of this method is that after all volatiles have been burnt
off
hot charcoal remains in the bottom can. I suspect because of its shorter
flame this charcoal if left to burn does not have as much effect on the
cooking pan of water at the top. Also it is necessary to increase primary
air to burn this charcoal, hence it is easier to extinguish it and keep it
as a by product, as you say it can be then used other cooking processes.
>
>The only purpose I would see is if the household has use for small
>quantities of charcoal for special cooking, ironing, etc. Then it could
be
>a useful "side product" of a woodstove. But this would hardly be relevant

>from the energy angle.

>
>There has also been some mention of sawdust stoves: a tin packed with
>sawdust around one or more sticks to make holes down the middle. Burns
when
>you light it. The design has been known for decades. The problem is that

>the stove cannot be regulated. Does anyone know any place where these
have
>proven their worth and are in regular use?

I merely tried out the age old principle which had been mentioned on the
list by Tom Reed, I simply reasoned that it was not a lot different in
principle to top light this and treat it as we had our wood chunks.The old
method was presumably to light and run in an updraft mode. To better
emulate
the situation with vertically arranged sticks I just increased the number
of
gas holes. I did have problems with regulation and had to increase primary
air, which probably equates to high excess air usage. As has been mentioned
in this thread, by Ronal and Tom Reed, much charcoal making is done
without
flaring the pyrolisis gases, this is held to be a polluting method in the
perceived wisdom of this list. Hence if a modified toplit idd twocan method
of carbonisation of sawdust could be used a pollution problem would be
eased.

Even if the heat could not be used for cooking, because of the lack of
control you mention and my experience of needing extra draft from an
insulated flue, there is scope for a flue of refractory material
maintaining
sufficient draw but also absorbing heat into its mass and then slowly
giving
up this heat after a short burn, much as a storage heater, for domestic
use.

As a further thought for Elsen, some previous discussion on the list
mentioned charcoal making in the exhaust of an ic engine. If the sawdust is
metered into the exhaust at a rate proportional to the engine load the char
dust could be collected in a cyclone and the exhaust gases be flared. There
may have to be some exhaust recirculation to keep the temperature below the
500C Tom Reed says is necessary for spontaneous combustion ( there being
sufficient excess oxygen present in a diesel exhaust at part load to cause
a
problem, I recall stories of buildings being demolished by dust
explosions).

On a charcoal usage front, is the world aware of the problem a water
company
in the UK has had on using activated bone charcoal to filter the drinking
supply, there is an outcry from both vegetarian and ethnic groups. How is
charcoal derived from bone which I thought was basically CaCO3?

I have been referred to a publication of the Indian Academy of Science 1983
edited by Prasad and Verhaart on Wood Heat for Cooking, not having library
facilities to hand immediately, is this still available?
AJH

From cetep at reacciun.ve Sun Dec 14 16:31:03 1997
From: cetep at reacciun.ve (Luis Miguel Abad)
Date: Tue Aug 31 21:35:46 2004
Subject: converting sawdust to charcoal briquettes
In-Reply-To: <199712140758_MC2-2BDB-BC3B@compuserve.com>
Message-ID: <34948824.1701@reacciun.ve>

Thomas Reed wrote:
>
> Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
> Colorado School of Mines & The Biomass Energy (non-profit)Foundation
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Dear Andrew Heggie (and stovers):
>
> I have been sitting on your "summary" letter (below) for a few weeks
> because it deserves a good answer.
>
> Your summary (to Ferguson) pretty well "sums" up the present state of the
> art - much progress being made using inverted downdraft stoves for cooking.
> Progress also in charcoal making. Many new ideas being tested "out back".
>
>
> Unfortunately, my outback has turned quite cold, so I sit here at the
> computer listening to those in warmer climates or with heated labs.
> However, I am planning a MAJOR campaign for Spring - after publishing
> Volume I - to move my understanding of these issues forward and, I hope
> give needed understanding and data in this critical field.
>
> Here is a challenge: The inverted downdraft stoves currently produce good
> cooking AND charcoal. If you need both how lucky! If you just want
> cooking, the air velocity needs to be increased about 20fold to accomplish
> gasification of the charcoal as well. In that case, the cross section area
> will DECREASE 20fold and you will have a one inch diameter gasifier for a
> 2.5 kW equivalent stove. That is where I started my thinking in 1985.
>
> How else can you consume the charcoal at the same rate as the wood?
>
> Onward, TOM REED
>
> ~~~~
>
> Summary Eric queried why we talk of charcoal making stoves
> At 17:01 11/11/97,dr. E.T. Ferguson wrote:
> >Dear Stovers,
> >
> >On this list there is a lot of discussion on the of ways producing
> charcoal
> >as a by- or co-product of a wood- or sawdust stove.
> >
> >I missed the beginning of this discussion. Can those who propose this
> >please explain why this is a good topic to research? In my view a stove -
>
> >to be economical - should adapt its heat output to the food being cooked.
> >When producing charcoal, stove will need to adapt to the efficiency of
> >charcoal production. It seems unlikely the two purposes will match.
>
> Andrew Heggie:I will have a try at this, I wondered what it was about when
> I
> searched the list for information on charcoal making, hence I came in from
> the opposite angle.
> As I understand the history of this: in researching the possibility of
> producing a smokeless biomas cookstove for under developed areas Ronal
> Larson and Tom Reed decided to light a fire on top of the fuel, whilst
> still
> drawing primary air up through the charge, to burn the pyrolisis gases
> secondary air entered above the fuel and was burned in a combustion area
> above the charge, This design lent itself to construction from two cans
> with
> the secondary air gap between. It also led to complete combustion of the
> pyrolisis gases which had not been possible in a fire lit at the botom (an
> updraft fire) Reed/Larson named this inverted downdraft burning. This
> twocan
> principle of IDD burning is being developed by ELK and Alex English amongst
> others.
>
> A side effect of this method is that after all volatiles have been burnt
> off
> hot charcoal remains in the bottom can. I suspect because of its shorter
> flame this charcoal if left to burn does not have as much effect on the
> cooking pan of water at the top. Also it is necessary to increase primary
> air to burn this charcoal, hence it is easier to extinguish it and keep it
> as a by product, as you say it can be then used other cooking processes.
> >
> >The only purpose I would see is if the household has use for small
> >quantities of charcoal for special cooking, ironing, etc. Then it could
> be
> >a useful "side product" of a woodstove. But this would hardly be relevant
>
> >from the energy angle.
>
> >
> >There has also been some mention of sawdust stoves: a tin packed with
> >sawdust around one or more sticks to make holes down the middle. Burns
> when
> >you light it. The design has been known for decades. The problem is that
>
> >the stove cannot be regulated. Does anyone know any place where these
> have
> >proven their worth and are in regular use?
>
> I merely tried out the age old principle which had been mentioned on the
> list by Tom Reed, I simply reasoned that it was not a lot different in
> principle to top light this and treat it as we had our wood chunks.The old
> method was presumably to light and run in an updraft mode. To better
> emulate
> the situation with vertically arranged sticks I just increased the number
> of
> gas holes. I did have problems with regulation and had to increase primary
> air, which probably equates to high excess air usage. As has been mentioned
> in this thread, by Ronal and Tom Reed, much charcoal making is done
> without
> flaring the pyrolisis gases, this is held to be a polluting method in the
> perceived wisdom of this list. Hence if a modified toplit idd twocan method
> of carbonisation of sawdust could be used a pollution problem would be
> eased.
>
> Even if the heat could not be used for cooking, because of the lack of
> control you mention and my experience of needing extra draft from an
> insulated flue, there is scope for a flue of refractory material
> maintaining
> sufficient draw but also absorbing heat into its mass and then slowly
> giving
> up this heat after a short burn, much as a storage heater, for domestic
> use.
>
> As a further thought for Elsen, some previous discussion on the list
> mentioned charcoal making in the exhaust of an ic engine. If the sawdust is
> metered into the exhaust at a rate proportional to the engine load the char
> dust could be collected in a cyclone and the exhaust gases be flared. There
> may have to be some exhaust recirculation to keep the temperature below the
> 500C Tom Reed says is necessary for spontaneous combustion ( there being
> sufficient excess oxygen present in a diesel exhaust at part load to cause
> a
> problem, I recall stories of buildings being demolished by dust
> explosions).
>
> On a charcoal usage front, is the world aware of the problem a water
> company
> in the UK has had on using activated bone charcoal to filter the drinking
> supply, there is an outcry from both vegetarian and ethnic groups. How is
> charcoal derived from bone which I thought was basically CaCO3?
>
> I have been referred to a publication of the Indian Academy of Science 1983
> edited by Prasad and Verhaart on Wood Heat for Cooking, not having library
> facilities to hand immediately, is this still available?
> AJH
>
> <

From elk at arcc.or.ke Mon Dec 15 02:37:19 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:46 2004
Subject: Still Here
Message-ID: <v01510100b0baabb0fb3a@[199.2.222.130]>

I'm still here, and still waiting for the magic solution of how to manually
convert sawdust to charcoal for onward briquetting using clay as a binder.

That'd be a great Christmas present!

The One-Can stove is currently churning out mandazis (a donut without a
hole) very successfully in a small food kiosk near here. It replaces three
stones and uses less than half the wood normally required. One fuel-load of
between 2.5 and 3 kg deep frys 8 kg of flour (very little else in a
mandazi), the charcoal produced is decanted to an improved ceramic jiko
(without being extiguished) and is used to prepare 10 litres of tea.

I'm sending one of our One-Cans to an informal metal worker (jua kali
fundi) in order to have it replicated & thereby costed. Will revert with
results on both cost & quality.

Been a bit busy 'round here lately, so I've not fired up my old 12 foot
auger over a wood fire to see how it acts as a sawdust carboniser. Should
be on to that later this week. If it looks promising, I'll have to figure
out how to flare the volatiles produced from the carbonising sawdust
beneath the auger as a primary heat source. Ideas anyone?

Robert van der Plas of the World Bank ('Burning Charcoal Issues') and
Jeanette Scherpenzeel of the Biomass Technology Group B.V. (NL) dropped 'by
for a visit and took some clay-bound charcoal vendors waste briquettes
after being shown the briquetter in action as well as some hot stoves.

Still churning out briquettes despite E' Nino interfering with sun-drying.
What a wet year! We've settled down to a consitant 250 kg (dry wt.) per day
using with a team of three. Day in, day out- no breakdowns! (yet).

Alex- any feedback from Queens U. on testing conducted on the One-Can
charcoal-making stove yet? From the echoing silence I assume that Christmas
is a busy time for Burt's.

All for now;

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From tmiles at teleport.com Thu Dec 18 17:25:01 1997
From: tmiles at teleport.com (Tom Miles)
Date: Tue Aug 31 21:35:46 2004
Subject: Bioenergy Lists on the Web
Message-ID: <3.0.32.19971218142708.00a7e8e4@mail.teleport.com>

Bioenergy List Participants,

Since we started the bioenergy lists we have been archiving list messages
on the web so that they contribute to the pool of online bioenergy
information. The web search engines periodically index the archives, so
that as the use of WWW searching increases we get more 'hits.'

Often people who access one of the list archive via the WWW post messages
to the list. The list administrators receive 2-6 "non-member" messages per
day. If they appear relevant list administrators will forward them to the
list. That is where many of the recent "forwards" from me and others come
from.

As a matter of policy I have been subscribing these individuals to the
lists before forwarding their messages, so that they will receive responses
and contribute to the discussion. In many cases they stay with us and their
contributions have been quite interesting.

The most accessed list - bioenergy - gets more than 1000 public hits
(requests or viewers) per day. The least - bioconversion - gets about 50.

Total requests for the last month are:

Bioenergy - 34,000 requests
Stoves - 14,600
Gasification - 6,500
Digestion - 3,800
Bioconversion - 1,500

BIOENERGY EMAIL LISTS

o Bioenergy (bioenergy@crest.org)
Moderator: Tom Miles (tmiles@teleport.com)
(Other Volunteers are Welcome!)
Archive:
<http://solstice.crest.org/renewables/bioenergy-list-archive/>
Digest: bioenergy-digest@crest.org

o Gasification (gasification@crest.org)
Moderators: Thomas Reed <REEDTB@compuserve.com>
Estoban Chornet (Chornete@tcplink.nrel.gov)
Archive: <http://www.crest.org/renewables/gasification-list-archive>
Digest: gasification-digest@crest.org

o Anaerobic Digestion (digestion@crest.org)
Moderators: Phil Lusk (plusk@usa.pipeline.com)
Pat Wheeler (patrick.wheeler@aeat.co.uk)
Richard Nelson (rnelson@oz.oznet.ksu.edu)

Archive: <http://www.crest.org/renewables/digestion-list-archive>
Digest: digestion-digest@crest.org

o Stoves (stoves@crest.org)
Moderators: Ronal Larson(larcon@csn.net),

Archive: <http://www.crest.org/renewables/stoves-list-archive/>
Digest: stoves-digest@crest.org

o Bioconversion (bioconversion@crest.org)
Moderators: Tom Jeffries <twjeffri@facstaff.wisc.edu>
Archive:
<http://www.crest.org/renewables/bioconversion-list-archive/>
Digest: bioconversion-digest@crest.org

Happy Holidays

Tom Miles

------------------------------------------------------------------
Thomas R. Miles tmiles@teleport.com

1470 SW Woodward Way http://www.teleport.com/~tmiles/
Portland, Oregon, USA 97225 Tel (503) 292-0107 Fax (503) 605-0208

From english at adan.kingston.net Fri Dec 19 08:03:05 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:46 2004
Subject: Resources on the WWW
In-Reply-To: <01BD0874.FD56E1C0.btremeer@dds.nl>
Message-ID: <199712191407.JAA12964@adan.kingston.net>

Dear Grant and Stovers all.
I think its great to have access to information like your thesis. It
inspired me to set up a rudimentary version of the vent hood built
out of an oil drum. Check it out at

I can see several advantages, aside from reducing my exposure to stove
emissions. The dilution effect allows me to measure CO levels that
exceed the 2000ppm limit of the tool I use. Measurements of the
venturi burner with out its chimney can be made. Comparison will be
easier.

One disadvantage might be the difficulty in gaining information about
the excess air dynamic with in the stove. This is very important for
anyone who is trying to make design changes which affect emissions.

On this question of emissions, in your thesis Chapter 3 3.2Emissions,
the following statement is made; "CO is a product of incomplete
combustion which forms where there is insufficient oxygen or where the
temperature is high. At lower temperatures and in the presence of
sufficient oxygen the formation of CO2 dominates (see Shafizadeh
1981:123). We therefore would expect CO to increase with increasing
burn rate and fire temperature." My understanding is that high
temperatures are key to reducing CO emissions. ??? I am unlikely to
see ( Shafizadeh 1981:123)
See you later
(Alex 1997)

> >From Grant Ballard-Tremeer btremeer@dds.nl
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Greetings Stovers,
>
> I'm finally able to announce that the full text of my thesis on the
> 'Emissions of Wood-burning Cooking Devices' is available on my homepage.
> If anyone would like to access it, the address is
> http://www.ilink.co.za/~grantt. Please email me with comments, questions,
> or any points you would like to discuss and I'll do my best to respond. I
> hope to add other articles and relevant material regularly.
>
> With best wishes
> Grant
>
>
> Detailed Table of Contents of material available at
> http://www.ilink.co.za/~grantt
>
> 1 Overview
> 1.1 The extent of the problem
> 1.1.1 The health impact of combustion emissions
> 1.1.2 World-wide exposure to biofuel combustion products
> 1.1.3 Lack of alternatives
> 1.2 The gap in stove testing methods
> 1.2.1 The need for stove emission measurement
> 1.2.2 The difficulty of measuring emissions from stoves used by the rural
> poor
> 1.2.3 Historic focus on efficiency not emissions
> 1.2.4 The existing methods of emission measurement
> 1.2.5 Issues considered in this study
> 1.3 Summary
> 1.4 Thesis organisation
>
> 2 Apparatus
> 2.1 Extraction booth
> 2.2 Extraction control
> 2.3 Orifice flow meter
> 2.4 Obscuration meters
> 2.5 Gas analysis
> 2.6 Weighing platform
> 2.6.1 Separation of wood and char
> 2.6.2 Measurement of fuel burn rate and water evaporated
> 2.7 Water temperature
> 2.8 Fire temperature
> 2.9 Data acquisition
> 2.10 Summary
>
> 3 The effect of an extraction hood
> 3.1 Background and aims
> 3.2 Experimental design
> 3.2.1 Variables and hypotheses
> 3.2.2 Levels
> 3.2.3 Significance
> 3.2.4 Treatment combinations, repetition and randomisation
> 3.2.5 Other variables
> 3.3 Results and discussion
> 3.3.1 Fire temperature, power and efficiency
> 3.3.2 Emissions
> 3.4 Summary and conclusions
>
> 4 The screening of experimental variables
> 4.1 Background and aims
> 4.1.1 Stove type
> 4.1.2 Amount of water
> 4.1.3 Pot lids
> 4.1.4 Wood type
> 4.1.5 Wood size
> 4.2 Experimental design
> 4.2.1 Variables and hypotheses
> 4.2.2 Levels
> 4.2.3 Significance
> 4.2.4 Treatment combinations, repetition and randomisation
> 4.2.5 Other variables
> 4.3 Results and discussion
> 4.3.1 Stove type
> 4.3.2 Amount of water
> 4.3.3 Pot lids
> 4.3.4 Wood type
> 4.3.5 Wood size
> 4.3.6 First order interactions
> 4.4 Summary and conclusions
>
> 5 Real-time emission patterns
> 5.1 Background and aims
> 5.1.1 The definition of the problem and the method of solution
> 5.1.2 Previous studies
> 5.2 Experimental design
> 5.3 Results and discussion
> 5.3.1 The open fires
> 5.3.2 The enclosed stoves
> 5.3.3 Extraction analysis of variance
> 5.3.4 Variable screening analysis of variance
> 5.4 Summary and conclusions
>
> 6 The simulation of a dilution chamber
> 6.1 Background and aims
> 6.2 Experimental design
> 6.3 Results and discussion
> 6.3.1 The effect of cooking task on chamber method accuracy
> 6.3.2 The effect of air exchange rate on chamber method accuracy
> 6.3.3 The effect of cooking device type on chamber method accuracy
> 6.4 Summary and conclusions
>
> 7 Summary and conclusions
> 7.1 The need for this work
> 7.2 The aim of this work
> 7.3 The approach
> 7.4 The effect of the extraction hood on emission measurements
> 7.5 The study of the effect of five experimental variables
> 7.6 The relationship between CO, SO2 and TSP
> 7.7 The validity of assuming constant emission rate in chamber tests
> 7.8 The significance of this work
> 7.9 Areas for further work
>
> Appendix A Experimental results
> A.1 Included on the diskette
> A.2 Installing and removing the program
> A.3 What the analysis program does
> A.3.1 Emissions
> A.3.2 Efficiency
> A.3.3 Smoke and specific optical density and TSP
>
> Appendix B Requirements of a testing method
> B.1 International standards versus testing guidelines
> B.2 Absolute versus comparative measurements
> B.3 Integral versus real time measurements
> B.4 Indirect versus direct measurements
> B.5 Water boiling test versus other methodologies
> B.6 Recommendations
>
> Appendix C Factorial analysis
> C.1 Identifying variables and defining hypotheses
> C.2 Selection of levels
> C.3 Level of significance
> C.4 Treatment combinations, repetition and randomisation
> C.5 Calculation methods
>
> Appendix D Wood combustion
> D.1 Oxidant
> D.2 Fuel
> D.2.1 Moisture
> D.2.2 Inorganic Materials (Ash)
> D.2.3 Organic Materials
> D.2.4 Direct combustion
> D.3 Pyrolysis
> D.3.1 Ratio of volatiles to char
> D.3.2 Initiation reactions
> D.3.3 Pyrolysis reactions
> D.3.4 Volatiles
> D.3.5 Char
> D.4 Combustion
> D.4.1 Reaction Rate
> D.4.2 Combustion of Activated Carbon
> D.4.3 Combustion of Volatiles
> D.4.4 Sulphur Dioxide
>
> Appendix E Case study: cooking devices compared
>
> References
>
>
>

______________
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
Tel 1-613-386-1927
Fax 1-613-386-1211
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From english at adan.kingston.net Fri Dec 19 08:18:53 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:46 2004
Subject: Opps
Message-ID: <199712191423.JAA13686@adan.kingston.net>

Stovers,
Check out simple vent hood at
http://www1.kingston.net/~english/Vent.htm

______________
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
Tel 1-613-386-1927
Fax 1-613-386-1211
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From larcon at sni.net Fri Dec 19 09:47:07 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:46 2004
Subject: A forwarded special stoves request
Message-ID: <v01540b00b0c037dc8ab0@[204.133.251.10]>

Stovers: A forwarded message from [TrueBrit <TruBrit@compuserve.com>]
>Hi.
>
> I am producing Barefoot in the Park at Springfield Community Thetre
>in Sp. Virginia, and we are desperetly seeking a pot bellied stove to
>borrow, rent . We open on Jan. 15th so as you can see this is now urgent.
>If I can't locate one locally could you please fax to my office a good
>picture so that we can attempt to build one. Thanks for your help in
>advance
>
>Fax. G.Morrison 202-761-0172

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

From CAMPBELLDB at cdm.com Fri Dec 19 15:21:10 1997
From: CAMPBELLDB at cdm.com (Dan Campbell)
Date: Tue Aug 31 21:35:46 2004
Subject: Fwd: ARI Network Update - December 19, 1997
Message-ID: <199712192030.PAA12316@cdm.com>

To: dan
Subject: ARI Network Update - December 19, 1997
From: "Dan Campbell" <CAMPBELLDB>
Date: 19 Dec 97 15:27:15
Cc: arinet

Dear ARI Network Members:

This bulletin contains notices from network members in Nicaragua and the
United States. Also enclosed is a summary of a recent article by Patrice
Engle and others on smoke exposure in Guatemla and an announcement of the
final version of an EHP annotated bibliography by John McCracken and Kirk
Smith.

We would like to update our distribution list, so please let us know if you
would like to remain on the mailing list for the ARI Network Update.

Regards,
Dan Campbell, EHP
campbelldb@cdm.com
www.access.digex.net/~ehp
***************************************************************
NEWS FROM MEMBERS OF THE ACUTE RESPIRATORY INFECTIONS NETWORK

Nicaragua/Latin America

We coordinate a Latinamerica Internet Network on Bioenergy. We are 60
people from 18 countries, and our interest also includes woodstoves and its
effects. If you have any short description about your programm and network
either in Spanish or Portugueze, we will be happy to circulate it among our
network members.

Regards

Rogerio Carneiro de Miranda
ATP/PROLENA/Nicaragua
Apartado Postal C-321
Managua, Nicaragua
telefax (505) 276 2015
EM <rmiranda@sdnnic.org.ni>
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

USA

Morning Sun Press publishes: COOKING WITH THE SUN: HOW TO BUILD AND USE
SOLAR COOKERS ($9.95). This book shows the reader how to build 2 ovens
and the "reflector cooker." It gives a brief history of solar cooking,
complete instruction with photos and drawings on building the cookers,
how to cook using the heat from the sun, 95 recipes, and resources.

The book which shows how to build ovens and the "reflector cooker"
has sold 30,000 copies and has been bought by people in other countries
who teach solar cooking. These countries include, many countries in
Africa, Spain, Mexico, countries in Central Amercica and others.

THE SOLAR STOVETOP COOKER: PATTERN, INSTRUCTIONS, RECIPES ($12.00) is a
new product that makes the construction of the reflector cooker easier to
build. All the critical angles are given in the pattern, and complete
step-by-step instructions. All you have to do is cut them out, trace them
onto cardboard and assemble the cooker. This "hot plate" gets 650 degrees
within minutes, weighs 3 pounds and can be built for $20.00 in materials.

I am currently working on a kit that will have all the pieces cut to size
and
the user will only have to assemble the cooker. It should be available
early
next year.

For more information contact: jack Howell, Morning Sun Press, PO Box 413,
Lafayette, CA 94549 ph/fax (510) 932-1383 emial: jdhowell@ix.netcom.com
**************************************************************************

Articles, papers, etc received this week on ARI

"Smoke Exposure of Women and Young Children in Highland Guatemala:
Prediction
and Recall Accuracy," by Patrice Engle; et.al. IN: Human Organization,
56(4):
408-417 Winter 1997.

In order to measure indigenous Guatemalan and young children's exposure to
smoke from
cooking fires, three techniques were compared: 1) observation; 2) recall 24
hours later based on duration of activities; and 3) recall 24 hours later
based on the time each activity started and stopped (elapsed time).

To measure recall accuracy, 43 women and their children under two years were
observed during meal preparation and consumption, and the next day were
asked
to recall these activities. Women were reasonably accurate when recalling
durations, but recall was significantly less accurate using elapsed times.
Recall accuracy increased when two days' measurements were averaged.

Women who are most exposed to smoke recognize its damaging effects-on
themselevs and on their chidren. However, there are few options available to
them to reduce their exposure. The most significant predictors of lower
exposure are type of stove, and type of house configuration-factors which
women ususallly have little control over. The only behavioral variables
that
related to lower exposure were absence of a husband, and a culturla patern
associated with speaking Spanish rather than monolingual Kiche.

Mothers who recognize the potentially damaging effects of the smoke were not
able to protect their young children from it. Many cover the child's head
with a cloth, but the strongest predictor of child exposure is the child's
age, in addition to the characteristics of the mother. Thus the older
children can reduce exposure, but the younger children (less than 17 months
old) were significantly more likely to be in the kitchen.

A type of stove, called Planchas, are readily available in the region, and
are
being installed in many homes by family members and NGOs. Unlike gas stoves,
they are culturally appropriate and highly valued by families.
Unfortunately,
they are relatively expensive.

**********************************************************************

Final version of "An Annotated Bibliography on Acute Respiratory Infections
and Indoor Air Pollution with Emphasis on Children in Developing Countries,"
by J. McCracken & K. Smith. Environmental Health Project, December 1997.

This final version updates the June 1997 draft and includes citations and/or
abstracts to 192 studies. Copies are available on the EHP web site at:
http://www.access.digex.net/~ehp or contact Dan Campbell at email,
campbelldb@cdm.com to request a printed copy.

From larcon at sni.net Sat Dec 20 11:41:32 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:46 2004
Subject: central american stoves sales
Message-ID: <v01540b02b0c0fca59438@[204.133.251.12]>

Stovers: The following message came in today. I have asked Brad Hartnett
to join us on the list. Ron

I would be interested to learn of the response (if any) given to Nikhil
Desai's
(panalytics@juno.com) question of Nov 24 as I am investigating the appliance
market in Latin America. To reiterate:

2. Does anybody have an idea how much investment is made in stoves -
households, commercial establishments, etc., or any other type of
classification - annually worldwide or particular grouping? Although I
don't have any ready figures for other appliances, I figure one can
probably make claims such as "The Latin American domestic refrigerator
market is x billion dollars per year, y % of it in single-door,
auto-defrost models, and z % in Argentina, Brazil, Chile, Venezuela,
Colombia, and Mexico." Can someone give me an idea of what, for example,
is the market for domestic charcoal stoves in Asia?

Thankyou,

Brad Hartnett

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 Sat Dec 20 18:03:37 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:46 2004
Subject: Forwarded: Chimney problems...Is a stove my solution?
Message-ID: <v01540b00b0c1a9b181e6@[204.133.251.27]>

RWL: Stovers the following interesting question from DBarlo1 <DBarlo1@aol.com>

Gentlemen:

After almost ten years in our two fireplace home with a gas furnace, our
newest chimney cleaner-contractor has told us that we can not and should not
use our first floor fireplace. It seems that our upstairs fireplace which is
sealed uses one of the two passageways in our chimney and that our furnace
(installed sometime after the construction of our house circa 1880) tie into
the other passageway. We were told that a wood fire in the fireplace is
dangerous and could ignite the furnace escaping gas and exhaust. Since we used
the fireplace for 9 years without any problem, we are mystified. We would like
to do something about this. Any suggestions would be deeply appreciated. Merry
Christmas...D. Barlow

From btremeer at dds.nl Sun Dec 21 11:22:51 1997
From: btremeer at dds.nl (Grant Ballard-Tremeer)
Date: Tue Aug 31 21:35:46 2004
Subject: Resources on the WWW
Message-ID: <01BD0E2C.BF873120.btremeer@dds.nl>

------------------------------------------------------------------------
------------------------
Grant Ballard-Tremeer, btremeer@dds.nl, http://www.ilink.co.za/~grantt
------------------------------------------------------------------------
------------------------

Dear Alex

I'm glad you found the web site helpful and that it inspired you to build
your own hood. I took a look at the picture you've put on the web and I'm
suitably impressed!

In addition it will reduce the risk of bias in your measurements resulting
from the location of the gas measurement probe in a chimney since there is
more chance of the emissions being evenly mixed. I'm sure removing the
chimney from your burner makes quite a difference to its combustion
characteristics.

I'd be very interested to know 'CO mass per task' emission data for your
stove. If you take the task as 'heating water to boiling point as rapidly
as possible, and then simmering for 30 minutes' your results would be
comparable to mine. Note down emission concentrations regularly during the
process, and since you know the approximate flow rate through your hood you
can calculate this index relatively easily (the integral of the mass rate).
We could then compare this to figures calculated for the five stoves I
tested (compared in Appendix E,
http://www.ilink.nis.za/~grantt/AppdxE.htm). Of particular interest would
be comparison with the traditional three-stone fire.

Yes, the micro-details may be lost and it may be important to insert the
probe into the stove to measure concentrations at various places. On a
macro scale, though, dilution of the combustion gases will not alter the
calculation of excess air appreciably since the concentration of carbon
dioxide in air is so small.

There are two opposing movements of gases during the reaction. Oxygen is
diffusing inwards and the reaction products are diffusing outwards. As
temperature increases the reaction rate between carbon and oxygen speeds up
and more products diffuse outwards. This limits the inward diffusion of
oxygen and therefore the reaction to CO is favoured as the reaction is
starved of oxygen. The CO liberated may burn later to CO2 some distance
from the fuel surface if conditions are favourable. Perhaps someone else on
the list can explain this better, but as far as I understand it, that's
general idea.

Your stove gasifies the fuel in one combustion zone (forming predominantly
CO) and burns it at a later stage. It looks to me as if you are already
doing exactly what needs to be done in this second stage: ensure that there
is sufficient oxygen at a sufficiently high temperature in contact with the
reactants for as long as possible. The swirl inducer you use promotes this
contact as you know.

I hope this answer is satisfactory,
Happy testing (I, alas, no longer have access to my test rig so I look at
your enviously)
Grant

See you later
(Alex 1997)

______________
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
Tel 1-613-386-1927
Fax 1-613-386-1211
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From REEDTB at compuserve.com Sun Dec 28 08:41:47 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:46 2004
Subject: Charcoal or Pyrolysis?
Message-ID: <199712280845_MC2-2D5C-12C5@compuserve.com>

Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
Colorado School of Mines & The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Bhatta, Miles et al:

I applaud Bhattacharya's weighing in on charcoal/pyrolysis. He is an "old
timer" in this field and so has the perspective to add the remarks (below)
that many don't have. (However, I have never heard Mike Antal claim a 60%
yield. 45, maybe 50%.)

I agree that small charcoal at atmospheric pressure, field conditions
generally produces 20% charcoal (dry basis, DB), while the top down stoves
produce typically 25%, field conditions. These numbers will be vague and
anecdotal unless one were to add the volatiles remaining, iodine number,
BET surface or other measure of DEGREE OF PYROLYSIS. Still, they are
better than nothing.

Also I have proposed that typical conditions for primary charcoal (cooking
charcoal) making are to some extent self regulating, since above 275C the
mass becomes self heating and carries naturally to about 440 C without
external heat. Thus many different processes could produce the same yield.

~~~~
It is not INappropriate for the charcoal discussion to appear on the
GASIFICATION node, since gasification involves pyrolysis. However, our
motives are to NOT produce charcoal, but convert it to gas, so the
discussion is here in a negative sense.

Also, occasionally misguided enthusiasts wish to use charcoal gasifiers for
engines. They are easier to make (less tar) but wildly wasteful of the
energy in the biomass, since charcoal yields seldom exceed 30% even in
commercial (non-Antal) charcoal production.
In the same way it is on the STOVE node in a negative sense. To the extent
that a stove produces charcoal, it doesn't produce heat. Ron Larson
(moderator) sees charcoal production as a positive feature of the inverted
downdraft (top burning, charcoal producing) stove, since charcoal is much
in demand in Africa and other less developed countries. However, it is in
demand for cooking and if the biomass stoves are good enough, they wouldn't
need charcoal, so we agree to disagree on that point.

Most of the charcoal threads so far have been in STOVES. Now they are in
GASIFICATION. Any new visitor could get confused.
~~~~
Tom Miles: Is there enough interest so that we have a CHARCOAL node at
CREST?

MIKE ANTAL: Would you be willing to master a Charcoal node if one forms?
What is your top yield of REAL charcoal? (NOTE: I can't find Antal's
address - would someone forward this to him and send me his address?)

Danny Day: Better get in on this discussion site, wherever it winds up.

Comments? TOM REED
~~~~
Bhattacharya says:

Dr. Bhagade's pyrolysis results are interesting. But here are a few words
of caution.

i) The reported yield (if on dry basis) is too high. In general for
Biomass in small sizes the charcoal yield is less than large-sized
biomass, for example, wood logs. (This is mainly due to less chance of gas
phase secondary reaction taking place inside the pyrolysing solid as well
as faster heating rates in case of small aprticles.) I would expect an
yield well below 30% for small biomass in field condition.

ii) Prof. Antal's carbonization technique is different from conventional
charcoal making. It involves carbonization under moderate pressure.
He has found yields exceeding 60% in some cases. As far as I know, there
is basically no commercial plant yet based on this approach.

S.C. Bhattacharya

-------------------------------------------------------------------
S. C. Bhattacharya Voice : (66-2) 524 5403 (Off)
Professor 524 5913 (Res)
Energy Program
Asian Institute of Technology Fax : (66-2) 524 5439
PO Box 4, Klong Luang 516 2126
Pathumthani 12120
Thailand e-mail: bhatta@ait.ac.th
-------------------------------------------------------------------
<

From larcon at sni.net Sun Dec 28 17:16:03 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:46 2004
Subject: Forwarded: More questions on older stoves
Message-ID: <v01540b03b0cc4f63309a@[204.133.251.46]>

Stovers - anyone able to help?

>Date: Sun, 21 Dec 97 20:35:36 -0800
>From: Adrien Flaherty <Adrien@popalex1.linknet.net>
>Organization: Locations Real Estate
>To: stoves@crest.org
>Subject: chambers stove parts
>
>interested in ordering parts for a chambers stove...know of any mail
>order catalogs that carry chambers parts?

#2:
From: ATM456 <ATM456@aol.com>
Message-ID: <1fb1beb2.349fea84@aol.com>
Date: Tue, 23 Dec 1997 11:44:50 EST
To: stoves@crest.org
Subject: Chambers stoves

I have an old Chambers gas stove that is in good working condition is there
anyway to find out how much its worth and where can I get parts if needed.

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 Sun Dec 28 17:16:12 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:46 2004
Subject: Forwarded message on extrusion
Message-ID: <v01540b02b0cc4e32e918@[204.133.251.46]>

Stovers - Anyone able to help? Ron

Date: Mon, 22 Dec 1997 21:47:36 +1100
From: Garry Kindley <gwkindl@connexus.apana.org.au>
To: stoves@crest.org
Subject: Briquette manufacturing Equipment

I am searching for equipment capable of extruding a 65mm log from
shavings and sawdust.

Do you have any contacts

gwkindl@connexus.apana.com.au

Regards

Garry Kindley

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

From elk at arcc.or.ke Mon Dec 29 13:15:39 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:46 2004
Subject: one vote
Message-ID: <199712291820.VAA10893@arcc.or.ke>

>Tom Miles: Is there enough interest so that we have a CHARCOAL node at
>CREST?

I'm all for it- maybe some of my please for help* would be better rec'd in a
CREST charcoal forum.

Aknowledged; it'd take a while to form.

elk

*has anyone anywhere at anytime developed a low/appro tech way of converting
sawdust into charcoal dust????

""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
""""""
Elsen L. Karstad
P.O. Box 24371
Nairobi, Kenya

Fax (+ 254 2) 884437
Tel (+ 254 2) 891531

From larcon at sni.net Mon Dec 29 23:37:10 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:46 2004
Subject: Forwarded: woodstove info.
Message-ID: <v01540b03b0ce1bd22f66@[204.133.251.7]>

Hi....saw a conversation from Nov. about EPA not putting their list of
certified
woodstoves on the net, yet. Is this still the case, as of last few days of
the year?

What I'm actually looking for is not only the EPA certification,
but also the BTU rating of a particular stove a client saw,
but they didn't get clear info. on reaching the manufacturer.
Any clues to finding such data?

Thanking you in advance, and Happy New Year!
Robert Gay, Architect
Radius Associates, Tucson
Valleymind <Valleymind@aol.com>s

BioEnergy Lists: Improved Biomass Cooking Stoves

December 1997 Biomass Cooking Stoves Archive