[Stoves] cook stoves for Cameroon
Anh
ntanh at greengenvn.com
Thu Sep 18 06:26:38 CDT 2014
Huck, Ron and list,
I am Anh from GreenGenStove in Vietnam, we are making TLUDs and I'd like to
share some experience that may help a bit.
TLUD made charcoal and my customers can use that charcoal in 2 ways:
- Leave it there to burn in the stove to cook something that need
long time, low heat (like stews, bones boiling,.) at the end of normal
cooking.
- Put out the fire to keep the charcoal for later cooking using dry
sand or soil.
So I am sure that char are accounted for by users.
TLUD require to cut fire wood to short pieces to fit in the stove (we got
this complain all the time) but it can use many other biomass too,
especially corn cobs which is very hard to burn with three stones or some
other stove. If you have carpenter workshops nearby, all the little wood
junks from the shop can be great fuel, no need to cut and it is much better
quality than normal soft wood/branches that normally used for cooking. Saw
dust can be great too but you would need extra biomass box (a kind of
retort) to use it. TLUD can adjust the fire level (controlling the primary
air) and require almost no fire tending so that can somehow obsess the
extra time needed to prepare fuel.
Another advantage of TLUD is fire up time, for us is less than 30 secs,
which impress all the users.
We currently working in 12 mountainous provinces in north of Vietnam and the
fuel availability, cooking habit are varied from place to place, so we need
to learn about the customers before deciding which would be the best selling
points to them (among a dozen of advantages of TLUD or any improved cook
stove). Changing cooking habit would be the most difficult thing or at
least, it will take the most time to change.
Regards,
Anh
From: Stoves [mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of
Ronal W. Larson
Sent: Thursday, September 18, 2014 11:43 AM
To: Huck Rorick; Discussion of biomass
Subject: Re: [Stoves] cook stoves for Cameroon
Huck, list, cc Paul
I read all the good information provided by the young person who
answered your questions. Tell him/her that he/she did a good job.
The main new information I got was that your part of the
Cameroons has to follow a practice of slash and burn. This requires
enormous effort - way more I'll bet than the practice of finding firewood.
And the time before needing to slash is probably getting shorter - and
little land is probably available to produce cash crops.
I suggest you google for the words "slash and char" (especially
the website of Dr. Christoph Steiner), "Terra Preta", "biochar", etc. The
idea of char-making stoves is intimately tied in with the idea of soil
improvement - with the most prominent means for low income families in
countries like the Cameroons being that of saving the char for placement in
soil - to get improvements in yield, but also to avoid having to continually
be moving their ag plots.
Prof Lloyd has indicated today that char from char-making stoves
will be thrown away. Will not happen.
More below
On Sep 17, 2014, at 8:27 PM, Huck Rorick <huckrorick at groundwork.org> wrote:
Hi All,
I found myself a little confused by the discussion.
Not being expert in the field, this is how I would pose my questions:
1. There is a certain amount of energy per kilogram of wood (I'm going
to stick with wood for the moment rather than all biomass).
[RWL1: Always very close to 18 MJ/kg if dry. You need to be
sure that only dried wood goes into any stove.
1.
2. When burned, some of that energy is realized and some is not, i.e.
there is not complete combustion. How complete is the combustion? How much
energy is released? That would be the first measure. I want this because
it tells me about one component of the system and is useful for design. It
does not tell me the net result for the user.
[RWL2. The three stone fire might give you only 10-15%
efficiency. Improved stoves at least twice that. Part of the loss is in CO
and particulates. Char-making stoves usually show up best in EPA testing.
2.
3. How much of the released energy goes into cooking? That would be my
next measure. That should tell me what weight of wood people have to
collect to cook their food. It is worth noting that the amount of energy
that goes into cooking is also affected by the pots and lids used as well as
how they fit onto the stove.
[RWL3: Plenty of data on this - for both total combustion
(look up "Rocket stoves") and char-making (TLUDs). Yes on your qualifiers.
3.
4. It is also important to know how much energy was expended to get the
fuel and prepare it for use. Some of that energy is human energy so it gets
treated a bit differently and has a different impact. For example, it
doesn't convert simply to climate impact (are humans low global warming gas
emitters?). If you cut up the fuel a lot and process it a lot there is a
cost there. I don't know how that stacks up for gasifiers vs other stoves.
[RWL4: For sure the TLUDS will require more effort in fuel
preparation. But that also can be balanced if you can avoid slash and burn.
Humans are not low global warming emitters. Your village is one of the
lowest of course - but there will eventually be some funds transfer to the
Cameroons for help in carbon sequestration - with biochar likely to be a
least cost way. Cutting wood can be not so onerous if you start with small
stuff (branches not trunks). Plan on selling the big trees, not using them
for cooking. Also grasses may work where you are.
4.
5. Regarding charcoal. I am presuming you can still use the charcoal.
I was, apparently erroneously, under the impression that gasifier stoves
could continue to receive primary air and therefore burn the charcoal. I
actually liked that idea because it was simple and used most of the energy
in the stove. If you take the charcoal out of the stove you then have a
couple of options for using it. You can burn it in another stove, which has
some appeal as you can do a different kind of cooking with it (e.g. BBQ, or
?). But also seems like quite a bit of work and complication for a small
amount of charcoal. Or, you can use it in the soil. So another question:
[RWL5: Yes you can use charcoal for cooking - but do not use in
the same device used to make it. It is much dirtier and less efficient to
use the same stove. But yes to your last sentence on putting in soil. Your
"clients" should try it with a few small "holes" - not a whole field.
Comparison and experimentation is critical. We know of cases near you that
were so positive that theft hindered reporting.
5.
6. Is a gasifier stove with charcoal (biochar) buried actually carbon
negative?
[RWL6: Yes. Not permanently - but hundreds (maybe thousands)
of years is enough to count.
6.
7. Then the other important measure: what are the emissions?
[RWL7: There is a ranking system (1:4), with char-making
stoves generally the highest. The most recent reporting on this list was
about work by Mr. Kirk Harris - generally well over 4.0 But they can be
done badly as well.
7.
And, a kind of crude question: with the ins and outs of this discussion is
it the case that rocket stoves or some other stove is more efficient than
the gasifiers? In my question by efficiency I mean kg of wood required for
a Cameroonian to cook their meals?
[RWL8: Almost certainly the Rocket will use less fuel for
cooking. But not true for an exceptional TLUD vs a poor Rocket. But if
you get 50% more produce from a garden, many are saying that is a tradeoff
worth making (and having the same garden year-after year).
Which stove do they have to carry more wood for and do more fuel preparation
for? (I'm not sure how you measure the combined work for those tasks).
[RWL: Too little knowledge on my/our part of your fuel choices.
Maybe there is a waste product all over the place you can be using in a TLUD
(and not in a Rocket). Corn cobs? a nice reed? palm waste?
There is a serious difference in the time needed to tend a fire
in the two types as well - much less for a TLUD. Maybe there is a local
need for char - and the sale can justify the extra time spent finding and
preparing fuel. There is no such income potential with Rockets. But my
main concern is that you apparently have some very poor soil - and the best
way I know of to fix that is with charcoal.
Ron
Huck
From: Paul Anderson [mailto:psanders at ilstu.edu]
Sent: Monday, September 15, 2014 9:25 PM
To: Discussion of biomass cooking stoves
Subject: Re: [Stoves] cook stoves for Cameroon
Huck,
Crispin wrote:
Thus 'gasifiers' are getting rated as if they do not consume fuel that is
actually consumed.
Crispin's point is that wood that is turned into charcoal is no longer wood.
THAT is true. But there are two ways to state the efficiency: Fuel
efficiency and Energy efficiency. Charcoal that is created is no longer
wood. But it is a fuel made from wood that was transformed. And it
typically represent 25% to 35% of the energy that is in the dry weight of
the wood.
You indicated that the area is reasonably wooded. So it is not a case of
scarcity of wood.
If the created charcoal is put into the soil as biochar, then that energy
content is no longer available.
You as the project leader and with your personnel can make the decision
about how to read the numbers in the reports on stove efficiency (of fuel or
of energy).
Paul
Doc / Dr TLUD / Prof. Paul S. Anderson, PhD
Email: <mailto:psanders at ilstu.edu> psanders at ilstu.edu
Skype: paultlud Phone: +1-309-452-7072
Website: <http://www.drtlud.com/> www.drtlud.com
On 9/15/2014 10:45 PM, Crispin Pemberton-Pigott wrote:
Dear Huck
Just one quick point:
"The gasifier, as I understand it, is more efficient and has lower
emissions."
It depends on the test method and the metrics. It is fashionable to use the
GACC-WBT and that test does not report fuel consumption, it reports the fuel
mass equivalent of the energy consumption, treating charcoal left over as
unburned raw fuel (meaning it says the wood was not consumed).
Thus 'gasifiers' are getting rated as if they do not consume fuel that is
actually consumed. When you assess the performance be sure you are clear on
how the method calculates performance and what the metrics are. You may want
to measure ( and weigh) fuel needed per cooking cycle rather than use any
calculated numbers from a complex test protocol.
For evaluation of performance I recommend the CSI-WHT which is a water
heating test (no boiling) and a measure of the raw fuel needed per
replication of the cooing cycle. It is used by the WB in the Clean Stove
Initiative in Indonesia. Documentation (some anyway) is available.
Regards
Crispin in Tamil Naidu
_______________________________________________
Stoves mailing list
to Send a Message to the list, use the email address
<mailto:stoves at lists.bioenergylists.org> stoves at lists.bioenergylists.org
to UNSUBSCRIBE or Change your List Settings use the web page
<http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylist
s.org>
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists
.org
for more Biomass Cooking Stoves, News and Information see our web site:
<http://stoves.bioenergylists.org/> http://stoves.bioenergylists.org/
_______________________________________________
Stoves mailing list
to Send a Message to the list, use the email address
stoves at lists.bioenergylists.org
to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists
.org
for more Biomass Cooking Stoves, News and Information see our web site:
http://stoves.bioenergylists.org/
_____
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3485 / Virus Database: 4015/8232 - Release Date: 09/18/14
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20140918/c6b001b6/attachment.html>
More information about the Stoves
mailing list