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<DIV><FONT size=2 face=Arial>Dear Otto</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=formo-o@online.no href="mailto:formo-o@online.no">Otto Formo</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=kchisholm@ca.inter.net
href="mailto:kchisholm@ca.inter.net">Kevin</A> ; <A title=formo-o@online.no
href="mailto:formo-o@online.no">Otto Formo</A> ; <A
title=stoves@lists.bioenergylists.org
href="mailto:stoves@lists.bioenergylists.org">Discussion of biomass cooking
stoves</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, October 14, 2010 7:01
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> SV: [Stoves] MUST CHARCOAL BE A
CAUSE FOR CONCERN?</DIV>
<DIV><BR></DIV>
<DIV>Dear Kevin,<BR>I very much agree with you, FAO is focusing on agriculture
and forest issues, WHO on health, UNDP on environment and s.o.<BR>They dont
see the "whole" picture and one "action" might to an extend even harm another.
<BR>Iam not saying that charcoal is "bad" or useless.<BR>Iam concerned the way
its made out of traditional kilns, polluting and wasting a lot of
energy.</DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial># Yes, I agree that the lack of overview, and the
focus on only one aspect of "The Big Picture" can address some problems, and
worsen others. </FONT></DIV><FONT size=2
face=Arial></FONT></BLOCKQUOTE>
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<DIV><BR>The TLUD can reach even 750 C which should be hot enough for any type
of cooking.</DIV>
<DIV> </DIV>
<DIV><FONT size=2 face=Arial># Certainly, the flame temperatures can be high,
but the cooking effect is different. Charcoal cooking is primarily by
radiation, giving much different heat treansfer characteristics than
convective flame heating. </FONT><BR><BR>Any type of fuel need some kind of
refinement or preparation, dont forgt that.<BR>This goes for charcoal and fuel
for the TLUD`s as well.<BR>I would not say that cutting branches with a
machete is "highly" prepared fuel.</DIV>
<DIV> </DIV>
<DIV><FONT size=2 face=Arial># Certainly, it is a very simple task to chop
smaller wood with a machette. A simple "fuel chopper" can do this very easily
also. However, the labor for chopping is excessive, and creates much extra
work for the Cook or her/his helpers. With a "Whole Body Machine", (eg, a
treadmill or a "Walking Pump") an adult in good shape can deliver a maximum of
about 1/5 of a Horsepower on a sustained basis. (5 people equals a 1 HP
engine) On the other hand, a machette, operated by one arm, can perhaps
deliver .01 to .05 HP (20 to 100 people on machettes equals a 1 HP engine)
Things become very different when waste products, such as fruit pits, screened
mill waste, etc are available. The labor content is greatly reduced, and the
only other step required is adequate drying. The TLUD can thus be a superb
tool for efficiently burning such a fuel, that would otherwise be difficult to
burn effectively. Rocket style stoves need "stickwood", that can be burned
directly with minimum processing. Both stove systems are very good for "the
right fuel", but are very bad when fed the wrong fuel.</FONT><BR><BR>If we
call the TLUD, a gasifier or a pyrolytic gas stove, cant be the big difference
to make an issue out of it.</DIV>
<DIV> </DIV>
<DIV><FONT size=2 face=Arial># All stoves are "gasifier stoves", and while the
term "gasifier stove" is a simplistic descriptive term, it is technically
unhelpful. TLUD's do a great job of burning pyrolysis gases in a controllable
manner, but they leave charcoal behind. Sometimes, the charcoal is a desirable
by-product, while under circumstances, it is a nuisance and a waste disposal
problem. Where small sized charcoal is wanted, then it is a superb tool, but
when charcoal is not wanted, it would be a very poor choice. True gasifiers
focus on converting 100% of the input fuel to a Fuel Grade Gas (FGG) or an
Engine Grade Gas (EGG) for burning elsewhere beyond the gasifier.
</FONT><BR><BR>Iam still conserned the way charcoal is produced and used in
developing countries on behalf of the people living there , the forest, water,
the local environmment and climate.</DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial># There are two major issues here:</FONT></DIV>
<DIV><FONT size=2 face=Arial>1: The way the biomass is converted to
charcoal</FONT></DIV>
<DIV><FONT size=2 face=Arial>2: The end use of the charcoal.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial># There is no question that the primitive methods
for producing charcoal are wasteful and inefficient, giving pollution
problems, low charcoal yield, and low energy utilization. There is much room
for advdantageous improvement to the charcoal production process. With such
"improved charcoal production systems", many of the objections to charcoal use
as a cooking fuel disappear. On the other hand, some are totally against
the use of charcoal as a fuel, suggesting that it should be reserved for use
in the soil as biochar to address Climate Change Issues. I personally think it
is very unfair of the First World to ask some of the poorest people in the
world to solve the CO2 problems we created, by burying fuel.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial># The overall problem is not at all as simple as
originally proposed. There are as many "problem sets" as there are differing
fuel availabilities, preferred cooking styles, and living
circumstances.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Best wishes,</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Kevin</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV><FONT size=2
face=Arial></FONT></BLOCKQUOTE>
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<DIV><BR>Otto<BR><BR><BR>> From: Kevin [kchisholm@ca.inter.net]<BR>>
Sent: 2010-10-14 04:53:32 MEST<BR>> To: Otto Formo [formo-o@online.no],
Discussion of biomass cooking stoves [stoves@lists.bioenergylists.org]<BR>>
Subject: Re: [Stoves] MUST CHARCOAL BE A CAUSE FOR CONCERN?<BR>> <BR>>
Dear Otto<BR>> ----- Original Message -----
<BR>> From: Otto Formo <BR>> Subject: SV:
[Stoves] MUST CHARCOAL BE A CAUSE FOR CONCERN?<BR>> <BR>>
<BR>> Dear Kevin,<BR>> what you actually are
"saying" is that people in developing countries have no common sense and
knowledge about polution from open fires.............<BR>> #
Not at all!! They work with what they have to accomplish what they want.My
comments were directed more at the FAO who put prime focus on simply saving
trees, rather than helping improving the lifestyle and health of the people.
<BR>> <BR>> Why do they use open fires for
cooking?<BR>> The most ovious reason is that they have no
choice or options.<BR>> Secondly, this is how it has been done
for centuries.<BR>> It "works", why change?<BR>>
The women do the collecting of wood and the cooking, so why
bather........<BR>> <BR>> # It is certainly misdirected to
put the focus on saving trees at the expense of harming people. Hopefully, it
will be a "win-win-win" situation where more efficient (less wood) and more
effective (do a better job of cooking the way they want to cook) and cleaner
(less harmful pollution) stoves can be configured. <BR>>
<BR>> Best wishes,<BR>> <BR>>
Kevin<BR>> Inferring that "charcoal is bad" overlooks part of
the function of some cooking systems. Some cooking styles must have the
intense heat that charcoal can produce. The point of my posting was to address
the whole problem, not just part of it. <BR>> <BR>> There is
also no question about that even the best and most efficient charcoal stoves
(without a chimmny) emitts far more CO than any TLUD gasifier stove.<BR>>
<BR>> # Charcoal stoves permit a unique cooking capability that
a TLUD cannot duplicate. There is probably a place for both stove systems.
Much work has been done on TLUD stoves in the past few years, and they are
working better now than ever. Less work has been done on charcoal stoves... no
doubt that they can also be greatly improved also. <BR>>
<BR>> # TLUD's are a neat stove for some applications, but they
are far from being a cooking panacea. They require a highly prepared fuel,
that they don't burn to completion, and they are basically a "batch stove".
They are not really a "gasifier stove" but rather a "pyrolysis gas stove",
that wants to leave charcoal behind. For some applications, the
production of charcoal can be a disadvantage, while for others, it can be very
advantageous. <BR>> # So, getting back to my basic point...
just what is the set of problems that need to be addressed? Why is charcoal a
problem? What can be done to reduce the problems with charcoal? What other
factors should be dealt with as part of the problem?<BR>>
<BR>> The other fact is that CO also kills people in the
"western" world as well by "missuse" of gas for heating and cooking, but it
does not mean that we should stop using it!<BR>> BUT we should
be VERY carefull by using open flames indoors without good
ventilation.<BR>> This is something we learn in school at early
age.<BR>> If any positive progress should be "stoped" by
missuse of just a few there is no way the "World" are going to move "forward",
ever.<BR>> Otto<BR>> <BR>> <BR>> >
From: Kevin [kchisholm@ca.inter.net]<BR>> > Sent: 2010-10-13
16:33:52 MEST<BR>> > To: Discussion of biomass cooking
stoves [stoves@lists.bioenergylists.org]<BR>> > Subject: Re:
[Stoves] MUST CHARCOAL BE A CAUSE FOR CONCERN?<BR>> >
<BR>> > Dear Rogerio<BR>> >
<BR>> > I think that the wrong question is being asked. One
can also ask the <BR>> > question: "Must wood be a cause for
concern?"<BR>> > <BR>> > 1: If the
ultimate concern is simply availability of fuel, then both
<BR>> > primitive wood stoves and primitive charcoal systems
are indeed a concern.<BR>> > <BR>> > 2: If
health, as a result of products of combustion considerations is the
<BR>> > ultimate concern, then both primitive cooking
systems are a concern.<BR>> > <BR>> > 3:
The good thing about 3 stone wood fires is that they emit gross irritants
<BR>> > that minimize the potential for users to be killed
during the cooking <BR>> > session from CO poisoning. Good
gharcoal stoves can be very efficient and <BR>> > not emit
apparent poisons, but if used in a confined space, the much more
<BR>> > efficient charcoal stove can kill the Family before
the meal is finished.<BR>> > <BR>> > 4:
Charcoal gives a quality of cooking that cannot be duplicated by a wood
<BR>> > fire.<BR>> > <BR>>
> Obviously, a dreadfully inefficient "3 Stone Fire" can be much safer than
an <BR>> > "Improved Cooking Stove" that has much higher
efficiency. There is so much <BR>> > smoke and poisons
coming off the 3 Stone Fire that people move upwind. An <BR>>
> "Improved Cooking Stove" might be improved just enough that people move
it <BR>> > inside a living space, and then they start dying
from all sorts of <BR>> > disorders. Charcoal stoves could
end up being superior, in that there might <BR>> > still be
enough "residual irritants" emitted such that the Cook uses it in a
<BR>> > well ventilated space.<BR>> >
<BR>> > The "problem", whatever it is, must be clearly
defined before one can arrive <BR>> > at a meaningful answer
to the "problem." A better question might be along <BR>> >
the lines of: "What is the best way for people to accomplish their desired
<BR>> > cooking task, with a given quantity of wood fuel,
while improving the health <BR>> > of the people using a
particular "cooking system?"<BR>> > <BR>>
> Perhaps someone else can formulate a better question that is more
relevant <BR>> > to whatever issue is of concern. There is
no point in promoting an "improved <BR>> > stove system"
that cuts wood usage in half, but doesn't cook the food the
<BR>> > way the people want it, and then kills them
afterward.<BR>> > <BR>> > Best
wishes,<BR>> > <BR>> >
Kevin<BR>> > <BR>> > ----- Original
Message ----- <BR>> > From: "rogerio carneiro de miranda"
<carneirodemiranda@gmail.com><BR>> > To: "Discussion
of biomass cooking stoves"
<stoves@lists.bioenergylists.org><BR>> > Sent:
Wednesday, October 13, 2010 9:01 AM<BR>> > Subject: Re:
[Stoves] MUST CHARCOAL BE A CAUSE FOR CONCERN?<BR>> >
<BR>> > <BR>> > Dear Crispin and others
who has responded.<BR>> > <BR>> > Making a
simple calculation (see table below), I found the
following<BR>> > numbers based on 1 kg of Eucalyptus
grandis, with 4650 kcal/kg as<BR>> > fuelwood, or 7600
kcal/kg as charcoal.<BR>> > <BR>> >
Considering the worst case scenarios, with woodstoves efficiency of
10<BR>> > to 15% one would get 450 to 698 kcal of energy
into the pot, and to<BR>> > have the same amount of energy
from charcoal into the pot, one would<BR>> > need to have
either a relative medium charcoaling efficiency of 20%<BR>>
> but with a charcoal stove with 30% efficiency, or charcoal stoves
of<BR>> > normal efficiency around 20% but with higher
charcoaling efficiencies<BR>> > of 30 or
40-%.<BR>> > <BR>> > Based on that,
shouldn't be logical to assume that under "primitive"<BR>> >
existing general conditions as seeing in the field today,
that<BR>> > cooking with wood is more energy efficient than
cooking with charcoal?<BR>> > <BR>> >
Assuming that woodstoves can easily achieve 20% efficiency
which<BR>> > delivers 900 kcal into the pot, and to do the
same job with charcol<BR>> > one would need a 30% energy
efficiency charcoal stove using charcoal<BR>> > produced at
40% charcoaling process, what is nearly impossible
to<BR>> > achieve.<BR>> >
<BR>> > Unless charcoal stoves of 40% are possible, so to
use with charcoaling<BR>> > kilns of high 30%
efficiency?<BR>> > <BR>> >
Rogerio<BR>> > <BR>> >
<BR>> > <BR>>
>
cooking with charcoal<BR>>
>
efficiency(%)
10%-20%-30%<BR>>
>
(kcal)<BR>> > charcoaling 10%
(760) (76) (152)
(22)<BR>>
>
20% (1520) (152) (304) (456)<BR>>
>
30% (2280) (228) (456) (684)<BR>>
>
40% (3040) (304) (608) (912)<BR>> > <BR>>
> cooking with fuelwood<BR>> > efficiency(%)
10% 15% 20% 30%<BR>> >
(Kcal) (450) (698)
(900) (1350)<BR>> > <BR>> >
<BR>> > <BR>> > <BR>> >
2010/10/12 Crispin Pemberton-Pigott
<crispinpigott@gmail.com>:<BR>> > > Dear
Rogerio<BR>> > ><BR>> > > We
discussed this a while back and I forwarded some example of the
energy<BR>> > > balance.<BR>> >
><BR>> > > Yes, the fact is there is nearly no
difference between the amount of food<BR>> > > cooked
with wood or that same wood turned into charcoal. The caveats
are<BR>> > > that I depends on the wood stove, the
charcoaling method and the charcoal<BR>> > >
stove.<BR>> > ><BR>> > > Those are
three huge variables, but for 'medium quality' on all
three<BR>> > > counts, the answers are about the
same.<BR>> > ><BR>> > > The overall
difference that one might be inclined to ponder is the amount
<BR>> > > of<BR>> > > energy that is
used to being the fuel to the cook. In the case of <BR>> >
> charcoal,<BR>> > > say in Mozambique, the distance
that one can profitably transport charcoal<BR>> > > is
far greater than that for wood because it is so much more energy
dense.<BR>> > > It is even better than coal because coal
usually has a lot of ash in it.<BR>> >
><BR>> > > So, when considering what to criticise,
replace and promote, one has to <BR>> > >
look<BR>> > > at the three main variables, what one could
do to change them, and what <BR>> > >
the<BR>> > > transport implications are. It is pretty
tempting to think of charcoal<BR>> > > making vehicles
using wood gas for locomotion, delivering charcoal to the<BR>>
> > cities. They would start off heavily loaded and get lighter as they
got<BR>> > > closer to town!<BR>> >
><BR>> > > I recall Cecil Cook and I having fun with
this equation some time ago.<BR>> > ><BR>>
> > What is always good (as Richard Stanley recently point out) is to
make <BR>> > > sure<BR>> > > that
all the chips and dust from the charcoal business end up in
<BR>> > > briquettes<BR>> > > of
some form. Usually the review of charcoal is made by a hostile agent
<BR>> > > and<BR>> > > the 'waste'
involved is emphasized, not the methods by which it can
easily<BR>> > > be made very efficient, all things
considered.<BR>> > ><BR>> > > There
is still a lot of this story to be told by someone with a talent
for<BR>> > > integrating technologies and stove
ideas.<BR>> > ><BR>> > >
Regards<BR>> > > Crispin<BR>> >
><BR>> > ><BR>> > >
+++++++++++++++<BR>> > ><BR>> >
>>I found the following quote on a FAO publication<BR>>
> > (http://www.fao.org/docrep/005/y4450e/y4450e10.htm), and I wonder if
this <BR>> > > is<BR>> > > a correct
statement responding to the question :<BR>> >
><BR>> > > "Must charcoal be a cause for
concern?<BR>> > ><BR>> > > The shift
from fuelwood to charcoal, even if it lasts only a few
decades,<BR>> > > could have major ecological
consequences if it is not kept under control.<BR>> > >
However, since charcoal stoves are more efficient than wood stoves,
the<BR>> > > ratio of primary energy to usable energy is
almost the same as with<BR>> > > fuelwood. Thus with
adequate supervision, management and support, the <BR>> >
> shift<BR>> > > does not need to disrupt present
levels of resource use."<BR>> > ><BR>>
> > What do you think? Can at the end, with actual stoves and
charcoaling<BR>> > > efficiencies, be the wood
consumption the same?<BR>> > ><BR>> >
> Rogerio<BR>> > ><BR>> >
><BR>> > ><BR>> > >
_______________________________________________<BR>> > >
Stoves mailing list<BR>> > >
Stoves@lists.bioenergylists.org<BR>> > >
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org<BR>>
> ><BR>> > <BR>> >
_______________________________________________<BR>> >
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