[Stoves] cook stoves for Cameroon

Tue Sep 16 03:13:02 CDT 2014

I do not find the discussion odd or out of topic.  I am saddened at all the
effort being put into gasifier stoves carefully designed to consume only
part of the fuel.  From the user's perspective, I can see no point in
spending a lot of energy and time in gathering fuel, only to have to throw
much of it away.  You have to appreciate the effort it takes to harvest wood
in the first place.  In some communities, we have found people collecting
wood 22h out of 24. The distance they have to travel follows a very skew
distribution, with a median distance of around 2km and a maximum distance of
over 6km.  Try walking 6km with 20kg of wood balanced on your head, and you
will get some idea of the effort involved. Then the wood still has to be
broken into a usable size, sapping yet more of your energy. 

Seen from this perspective, any efficiency metric that does not allow for
the loss of fuel by generating charcoal is plain wrong.  It may make some
stovers happy; it cannot be of assistance to those trying to stay alive at
the fringes of existence, for whom we are all trying to find clean means of
cooking.

Prof Philip Lloyd

Energy Institute

Cape Peninsula University of Technology

PO Box 652, Cape Town 8000

Tel:021 460 4216

Fax:021 460 3828

Cell: 083 441 5247

From: Stoves [mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of
Otto Formo
Sent: 16 September 2014 09:39
To: Stoves Bioenergylist
Subject: Re: [Stoves] cook stoves for Cameroon

Dear Paul and Huck,

I find this issue a bit od and out of "topic".
Why is suddenly WOOD such a "hot topic", when the most interesting part is
FUEL, Solid or Liquid from any type of biomass?

Producing charcoal or any other liquid fuel, you can not SKIP the processing
part, consuming energy as well.
This is also called a "Life circle" for a product (biomass fuel) - see
energy forestry.

Gasifier units; read
"Micro Kilns", utilizing the charcoal from wood or any other dry biomass for
cooking, will be more energy and fuel efficient, compared to traditional
made charcoal.

Because you are utillizing the energy content in the biomass for cooking,
while producing charcoal,  wheter you test the other way or another. 

Have a Nice day. 

Otto

  _____  

Date: Mon, 15 Sep 2014 23:25:02 -0500
From: psanders at ilstu.edu
To: stoves at lists.bioenergylists.org
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:  psanders at ilstu.edu   
Skype: paultlud      Phone: +1-309-452-7072
Website:  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
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/

_______________________________________________ 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/

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20140916/2131fd62/attachment.html>