BioEnergy Lists: Improved Biomass Cooking Stoves

From Reedtb2 at cs.com Wed Feb 2 08:00:03 2000
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:29 2004
Subject: Air Activated charcoal
Message-ID: <6a.7ec844.25c9842d@cs.com>

Dear All:

Mike says he can't post copies of his activated charcoal papers on the web
(see below) but will be happy to mail or fax them to those who request.

Nice Guy!

TOM REED

In a message dated 1/31/00 9:15:54 PM Mountain Standard Time,
antal@wiliki.eng.hawaii.edu writes:

<< Dear Tom: thanks for your kind words. I am happy to mail reprints of our
papers to anyone who is interested. Best regards, Michael. P.S. I often
receive requests to post such papers on the web. This is a very
complicated matter with serious copyright issues (that are well defined by
the ACS in the case of ACS publications). At least for the time being, I
will only supply hard copies by mail or fax.

On Mon, 31 Jan 2000 Reedtb2@cs.com wrote:

> Stovers and Gasers:
>
> I would like to introduce my friend Dr. Mike Antal, Coral Professor of
> Biomass at the University of Hawaii. In my book, he knows more about the
> theoretical aspects of pyrolysis and charcoal than most of the rest of us.
> He has also developed a process for making charcoal that gives a yield of
> 40-45%, rather than the 15-25% that most processes give.
>
> He recently visited my home in Golden and we spent a pleasant evening
> discussing the subtleties of biomass pyrolysis. He has just sent me two
of
> his most recent papers that are MUST reading for anyone interested in
> activated charcoal (or clean water for developing countries).
>
> "Synthesis of a High-Yield Activated Carbon by Air Gasification of
Macadamia
> Nut Shell Charcoal", X. Dai and M. Antal Jr., Industrial &Engineering
> Chemistry Research, Vol 38, pp 3386-3395, 1999
>
> "Preparation of Activated Carbons from Macadamia Nut Shell and Coconut
Shell
> by Air Activation", M Tam and M. Antal, Jr., Ibid, Vol 38, pp 4268-4276,
1999.
>
> Mike is achieving surface areas (and iodine numbers) > 1000 m2/g, with
yields
> over 15%, using air activation.
>
> Charcoal activation is a pain in the butt. In principle, it should be
> possible to use air for activation and Mike has found out how to do it.
>
> The three greatest technical challenges for the next century are Clean
> Cooking, Clean Power and Clean Water for all of humanity. The solution
lies
> in our hands.
>
> Yours truly, TOM REED BEF >>

 

To: Reedtb2@cs.com
Subject: GAS-L: Re: Introducing Mike Antal - and Activated charcoal
From: Michael Antal <antal@wiliki.eng.hawaii.edu>
Date: Mon, 31 Jan 2000 20:01:02 -0800
cc: Stoves@crest.org, Gasification@crest.org
In-Reply-To: <6b.1437010.25c6faad@cs.com>
Reply-To: gasification@crest.net
Sender: owner-gasification@crest.org

Dear Tom: thanks for your kind words. I am happy to mail reprints of our
papers to anyone who is interested. Best regards, Michael. P.S. I often
receive requests to post such papers on the web. This is a very
complicated matter with serious copyright issues (that are well defined by
the ACS in the case of ACS publications). At least for the time being, I
will only supply hard copies by mail or fax.

On Mon, 31 Jan 2000 Reedtb2@cs.com wrote:

> Stovers and Gasers:
>
> I would like to introduce my friend Dr. Mike Antal, Coral Professor of
> Biomass at the University of Hawaii. In my book, he knows more about the
> theoretical aspects of pyrolysis and charcoal than most of the rest of us.
> He has also developed a process for making charcoal that gives a yield of
> 40-45%, rather than the 15-25% that most processes give.
>
> He recently visited my home in Golden and we spent a pleasant evening
> discussing the subtleties of biomass pyrolysis. He has just sent me two of
> his most recent papers that are MUST reading for anyone interested in
> activated charcoal (or clean water for developing countries).
>
> "Synthesis of a High-Yield Activated Carbon by Air Gasification of
Macadamia
> Nut Shell Charcoal", X. Dai and M. Antal Jr., Industrial &Engineering
> Chemistry Research, Vol 38, pp 3386-3395, 1999
>
> "Preparation of Activated Carbons from Macadamia Nut Shell and Coconut
Shell
> by Air Activation", M Tam and M. Antal, Jr., Ibid, Vol 38, pp 4268-4276,
1999.
>
> Mike is achieving surface areas (and iodine numbers) > 1000 m2/g, with
yields
> over 15%, using air activation.
>
> Charcoal activation is a pain in the butt. In principle, it should be
> possible to use air for activation and Mike has found out how to do it.
>
> The three greatest technical challenges for the next century are Clean
> Cooking, Clean Power and Clean Water for all of humanity. The solution
lies
> in our hands.
>
> Yours truly, TOM REED BEF
>
> Thomas B. Reed
> President - The Biomass Energy Foundation
> 1810 Smith Rd., Golden, CO 80401
> Reedtb2@cs.com; 303 278 0558
> The Stoves List is Sponsored by
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From a.m.sebbit at techmuk.ac.ug Thu Feb 3 04:27:44 2000
From: a.m.sebbit at techmuk.ac.ug (adam sebbit)
Date: Tue Aug 31 21:36:30 2004
Subject: modelling of wood fired cooking stoves
In-Reply-To: <Pine.LNX.3.96.991224150824.5359L-100000@techmuk.ac.ug>
Message-ID: <001401bf6e60$a7d604c0$1b0112ac@techmuk.ac.ug>

Dear Mark,

Thanks for the information about the stoves. I am eagerly waiting for the
May 2000.
I have been testing charcoal stove. I wonder whether I have to conduct
low power and high power tests. Most of the literature I came across ,
describes the high power and low power methods of testing wood stoves.

A awaiting your comment.

Adam.M.Sebbit
Makerere University
Department of Mechanical Engineering
P.O.Box 7062
Kampala, UGANDA
Tel: 256 -41-541173 / 545029
Fax: 256-41-530686 / 530481
----- Original Message -----
From: Patrick Baker Ssesanga <ses@techmuk.ac.ug>
To: Adam Sebbit <amsebbit@techmuk.ac.ug>
Sent: Friday, December 24, 1999 7:08 AM
Subject: Fwd: Re: modelling of wood fired cooking stoves (fwd)

>
>
> Patrick Baker Ssesanga
> Electrical Engineering Dept.
> Makerere University
> P.O. Box 7062 Kampala
> Uganda
> Tel: 256-541191
>
> ---------- Forwarded message ----------
> Date: Thu, 23 Dec 1999 12:51:25 -0600
> From: kenneth mark bryden <kmbryden@iastate.edu>
> To: stoves@crest.org
> Cc: "Ronal W. Larson" <larcon@sni.net>, dstill@epud.org
> Subject: Fwd: Re: modelling of wood fired cooking stoves
>
> Fellow Stovers,
>
> I have followed the modeling discussion with great interest and apologize
> for coming late to the discussion, between research related travel, and
the
> end of the semester I have been swamped with work. This is a brief
> discussion of my work and as time and interest on the stoves list permits
I
> will build on this discussion.
>
> My research work is based on building a high fidelity, time-dependent
> models of wood stoves. These models will include wood combustion, solid
and
> gas phase reactions, low speed compressible flow and the coupling between
> the buoyant flow and the combustion rate. Using these model I hope to
> investigate combustion rate, efficiency, production of soot, production of
> pollutants, etc. The models we are building will be similar to the models
> used to investigate coal-fired furnaces (but slightly more advanced). The
> current model is being built in parts. The wood combustion sub-model is
> being built based on my doctoral work. The gas phase portion is being
using
> commercial software with user defined modules and extensions to couple the
> buoyant flow and the solid phase reaction. Currently we have a 3-D,
> nonreacting flow stoves model that we are building on. We are running it
on
> a 26 parallel processor machine. The primary goal of this work is to bring
> the same kinds of design tools used for advanced energy system design to
> stove design. Additionally, the results must be transferrable to real
> stoves used by real people. This is a challenging problem.
>
> Obviously this is a work in progress, the limiting factors are time and
> funding (as in all university research efforts). I currently have two
> graduate students (1 Ph.D. and 1 M.S.) and seven undergraduates working on
> this project. Most of our effort our focused on the rocket stove, this is
> because of ready access to the Approvecho (Dean Still and associates) and
> the potential for near term distribution of the rocket stove or
derivative
> stoves. I do have a stove from ARTI (Dr. Karve) and we have conducted some
> testing of the stove and done some global modeling but have not started
the
> high fidelity modeling effort.
>
> Currently there are several parts to this work.
> 1. Testing of stoves - part of this is just efficiency testing etc needed
> by others to compare stove performances, and to be an independent stoves
> testing facility. The other part of the testing is obtaining the detailed
> temperature profiles, combustion rates, gaseous products etc. needed to
> validate the model of the stove.
> 2. The development of global design guidelines that help predict stove
> performance.
> 3. The development of a high fidelity model described above.
> 4. Examining the interaction between the stove and the heat transfer
> medium, e.g. the pot or the frying pan surface.
>
> I hope by May 2000 to have preliminary results from the global modeling
and
> a test report detailing the performance characteristics of the rocket
> stove. By the end of the year 2000 I plan to have papers written on the
> first part of the modeling effort and on the impact of heat transfer to
the
> pan. I know there is a good deal of literature on some of this and hope to
> extend it.
>
> A couple of acknowledgments: working with Dean and friends is great, I
love
> their enthusiasm and hard work. I appreciate Dr. Karve's patience - she
> sent me a stove about a year which we have setup and tested and but have
> not yet had the resources to begin detailed modeling.
>
> One of my students is currently working on a Web page for our work, when
it
> is functional I'll let you know.
>
> If anyone has suggestions on research direction, opportunities for
> application of the stoves modeling, questions on the testing capabilities
> of my lab, questions on our modeling capabilities or computational
> resources, or any other questions. Just let me know. I am always looking
> for opportunities to collaborate on stoves work.
>
> Happy holidays!
>
> Mark Bryden
>
> Ron Larson wrote:
> >Dean:
> > Thanks for the clarification on your modeling approach. As Mark
is
> >a valued member of the "stoves" list, I know he and his students will
keep
> >us informed as appropriate. But if Mark can indicate anything at this
time
> >as to how far along he is in this process - or where there may be
> >theoretical modeling difficulties - the time frame will be helpful for
our
> >general stove improvement efforts and/or perhaps someone can offer some
> >ideas.
> >
> >Dean Still wrote:
> > >Aprovecho is working with Dr. Mark Bryden at Iowa State University who
is
> > >using the same computers and modelling techniques that they use to
analyze
> > >coal burning plants to investigate how wood burning cooking stoves
function.
> > >He has set up a stove lab and has students looking at different stoves
from
> > >around the world.
> > >
> > >Dr. Bryden is an expert at modelling and we hope that eventually he and
his
> > >students will successfully predict performance of various stoves.
> > >
> > >We're planning that if time permits he may be able to visit our team in
> > >Nicaragua when they begin work with Prolena and Rogerio Miranda in
February.
>
> ___________________________________________________________
> Mark Bryden, Ph.D. Assistant Professor
> kmbryden@iastate.edu Iowa State University
> ph: 515-294-3891 3030 Black Engineering Bldg
> fax: 515-294-3261 Ames, Iowa 50011-2161
> The Stoves List is Sponsored by
> Pyromid Inc. http://www.pyromid.net
> Stoves Webpage, Charcoal, Activated Carbon
> http://www.ikweb.com/enuff/public_html/Stoves.html
> http://www.crest.org/renewables/biomass-info/carbon.shtml
> Other Sponsors, Archive and Information
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> http://www.crest.org/renewables/biomass-info/
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From Reedtb2 at cs.com Thu Feb 3 07:48:03 2000
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:30 2004
Subject: The masked killer
Message-ID: <ba.12bf1a8.25cad2c0@cs.com>

But....

Photovoltaic typically costs $5,000/installed kW capacity (and only works ~12
hr/d).

Wood-gas generator systems cost $1,000-$2,000/kW capacity and work whenever
you want.

It's a lot easier to store a cord of wood then a cord of sunlight.

Onward...

TOM REED BEF

In a message dated 2/1/00 8:30:33 AM Mountain Standard Time,
denny@voyageronline.net writes:

<<
Mr. Doelle brings up many important points on the move toward biomass
energy production primacy as a "solution". In the US we are seeing an
inordinate emphasis on that BE primacy via subidies that might be better
spent on conservation, efficiency, PV and wind development. If you
doubt the possibility of forest killing potential, check out the "Forest
Residues" section of this site...
http://ermisweb.state.mi.us/biomass/publications/breakfast/#Forestry >>
The Stoves List is Sponsored by
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From willing at mb.sympatico.ca Thu Feb 3 14:10:15 2000
From: willing at mb.sympatico.ca (Scott Willing)
Date: Tue Aug 31 21:36:30 2004
Subject: The masked killer
In-Reply-To: <ba.12bf1a8.25cad2c0@cs.com>
Message-ID: <200002031910.NAA27734@smtp1.mts.net>

PMFJI, being cynical, and extrapolating from the subject at hand,

but...

As long as individual priorities are self-serving convenience and the
lowest immediate dollar cost, greener alternatives will stay on the
shelf.

Glad I don't have any kids to explain this to. "Sorry about your
future Johnny. We'd love to help, but it's too much hassle and
expense."

It's sad that we can't set our sights on loftier justifications than this.

Scott Willing

From: Reedtb2@cs.com
Date sent: Thu, 3 Feb 2000 07:46:56 EST
Subject: Re: The masked killer
To: denny@voyageronline.net, gasification@crest.org,
stoves@crest.org

> But....
>
> Photovoltaic typically costs $5,000/installed kW capacity (and only
> works ~12 hr/d).
>
> Wood-gas generator systems cost $1,000-$2,000/kW capacity and work
> whenever you want.
>
> It's a lot easier to store a cord of wood then a cord of sunlight.
>
> Onward...
>
> TOM REED BEF
>
> In a message dated 2/1/00 8:30:33 AM Mountain Standard Time,
> denny@voyageronline.net writes:
>
> <<
> Mr. Doelle brings up many important points on the move toward biomass
> energy production primacy as a "solution". In the US we are seeing
> an inordinate emphasis on that BE primacy via subidies that might be
> better spent on conservation, efficiency, PV and wind development.
> If you doubt the possibility of forest killing potential, check out
> the "Forest Residues" section of this site...
> http://ermisweb.state.mi.us/biomass/publications/breakfast/#Forestry
> >>
> The Stoves List is Sponsored by
> Pyromid Inc. http://www.pyromid.net
> Stoves Webpage, Charcoal, Activated Carbon
> http://www.ikweb.com/enuff/public_html/Stoves.html
> http://www.crest.org/renewables/biomass-info/carbon.shtml
> Other Sponsors, Archive and Information
> http://solstice.crest.org/renewables/stoves-list-archive/
> http://www.crest.org/renewables/biomass-info/
> For information about CHAMBERS STOVES
> http://www.ikweb.com/enuff/public_html/Chamber.htm

The Stoves List is Sponsored by
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From verhaarp at cqu.edu.au Sat Feb 12 04:55:59 2000
From: verhaarp at cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:36:30 2004
Subject: Downdraft Barbeque
In-Reply-To: <B4C8C61C.973%kanfam1@mcc.org.il>
Message-ID: <002301bf753f$47397300$044c4d8a@cqu.edu.au>

Dear Nehemia,

What you need for the downdraft system to work is sufficient chimney
height. My chimney is about 1.2 m, which when at operating temperature,
creates sufficient draft to make it work. My grate area is 120 cm^2,
sufficient for a heat output rate of roughly 5 kW which is equivalent to a
(dry) wood consumption of 1 kg/hour.

----- Original Message -----
From: "Nehemia Kantor" <kanfam1@mcc.org.il>
To: <verhaarp@cqu.edu.au>
Sent: Friday, February 11, 2000 3:46 AM
Subject: Re: Downdraft Barbeque

>
> My question is - are there any special measurements / dimensions I should
> take care of , in order to keep the downdraft circulation ?
>

Let us know how you are getting on.

Cheers,

Peter Verhaart
6 McDonald St, Gracemere Q 4702
Tel/Fax: +61 7 4933 1761
Mobile: 0412 457239
E-mail: p.verhaart@cqu.edu.au

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From elk at net2000ke.com Thu Feb 24 11:47:39 2000
From: elk at net2000ke.com (Elsen Karstad)
Date: Tue Aug 31 21:36:30 2004
Subject: Sawdust Carbonisation
Message-ID: <200002241653.TAA30976@net2000ke.com>

Stovers;We've been a quiet bunch eh?I ran another trial on an expanded version of my downdraft sawdust carboniser today & had some notable results.To summarize the technique; I have been fine-tuning a method of carbonising sawdust prior to low-pressure extrusion into briquettes using clay (25%) as binder with subsequent sun/air drying. The carbonising unit is now over nine meters tall, with a 2 m. dia. hollow cement base (combustion chamber) topped by a 7 m. chimney constructed of empty oil drums. Five 2m. X 3.5m. open shallow perforated ceramic bottomed flat-bed kilns are arrayed in a semi circle around the combustion chamber/chimney. Smoke (volatile products of combustion) is evacuated from beneath the kiln beds containing pyrolysing sawdust and into the bottom of the combustion chamber/chimney via valved pipes (20 cm dia.) and mixed with secondary air in the base of the chimney. The smoke is flared there, cleaning the exhaust to a clear gas and creating a tremendous flue vacuum all the way back through the beds of pyrolising sawdust. Sawdust is added by hand, covering charred black areas spreading across the top of the sawdust in the kilns. This restricts air and ensures that complete combustion to ash does not occur. Beds are cleared in sequence once the depth of carbonised sawdust has built up to between 15 and 20 cm.Modifications tested during this trial included increasing the diameter of the valved secondary air inlet pipe in the base of the combustion chamber from 10 cm to 20 cm. dia. All the carbonising kilns have been expanded by 25% in area to the current 35 m. sq. total area. The chimney has been extended by 3 m. height with an aim to increase flue suction.Today's trial resulted in 2,200 kg of air-dried sawdust (moisture approx 10%) being carbonised in 7.5 hours. That is 293 kg per hour, or 8.38 kg/hr/m2. kiln area.Conversion results are not yet available, as some water was used to extinguish smoldering charcoal, so I will wait a week or so before weighing the product, but previous conversions in the order of 23.5% have been realised. At this rate, the 2,200 kg of sawdust has been converted cleanly into 517 kg of charcoal powder suitable for briquetting.Regards to all;elk~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Elsen L. Karstad , P.O. Box 24371 Nairobi Kenyaelk@net2000ke.com     tel/fax (+ 254 2) 884437

From VHarris001 at aol.com Sun Feb 27 00:11:10 2000
From: VHarris001 at aol.com (VHarris001@aol.com)
Date: Tue Aug 31 21:36:30 2004
Subject: Evaporative Cooling for Biomass Drying?
Message-ID: <50.2116396.25ea0bc9@aol.com>

While perusing the web site for Fox Valve (venturi ejectors, etc.) I happened
across a page regarding evaporative cooling used in freeze drying. The page
states that "evaporative cooling is accomplished by pulling a vacuum on
moisture-enriched products within a vessel. An increase in vacuum results in
a lowering of the boiling point of the moisture, causing rapid evaporation.
During evaporation, the latent heat is given up - thereby reducing the
temperature of the product." The page further states that "a typical
multi-stage eductor unit can cool from 200°F to 35°F in 15 - 20 min."

Does anyone know whether 1) the material must first be heated for the process
to be efficient, and 2) once cool, is the material also mostly dry? If
vacuum cooling/drying is practical in the food processing industry, I'm
wondering if it could also be practical for use in biomass drying? Does
anyone have knowledge or experience with the use of vacuum drying of biomass?

This particular Fox Valve web page address is:
http://www.foxvalve.com/frameset-steam.html

Any feedback would be appreciated!

Regards,

Vernon Harris
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