Micro-gasification: Cooking with gas from biomass - Amper

Micro-gasification: Cooking with gas from dry biomass
‘PekoPe’ and ‘MUS’ designs by Paal Wendelbo (Norway)
The PekoPe (‗no problem‘ in vernacular Acholi from Uganda):
probably the simplest TLUD design with field-experience
very clean-burning, pyrolytic TLUD gasifier ‗energy unit‘
char-making optional, the user can chose whether to use
the energy for cooking or save the char for other use
very simple to make from any type of metal, ideal for replication
can be scaled from household sizes to institutional and
commercial sizes.
Technical features: The ‗energy unit‘ consists of an inner cylinder
as fuel chamber (or reactor), outer cylinder to guide and
preheat secondary air, a concentrator disk on top. Two vertical
handles on the outer cylinder ease handling and dumping of
char. Inner container fixed to outer container with spacers that
also function as legs to keep the fuel chamber above ground
and let the secondary air enter between the cylinders.
Handling: top-lit, batch-fed, cooking time depending on volume
and mass of fuel, up to 75 minutes is well possible. To extend
cooking time, the entire energy unit needs to be exchanged.
Combining more units under one pot support increases firepower,
e.g. for use in restaurants, industries or institutions.
HERA – GIZ Manual Micro-gasification Version 1.01 January 2011
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http://www.bioenergylists.org
Local PekoPe production
in Uganda in 1996.
Photo Paal Wendelbo
Paal Wendelbo is one of the two ‗fathers of TLUDs‘. Paal worked on burner units for stoves,
based on observations making smokeless fire when he was with resistance fighters in the
forest in Norway during the 2 nd World War. He started conceptualizing the first natural draft
TLUD in the late 1980s, about the same time but independent from the work of Tom Reed in
the US. After a lot of trying and failing he made a simple cook stove which was found very
clean burning when tested at Copenhagen Technical high school in 1988. It was introduced
in various countries where Paal worked: Malawi (1988, fuelled with grass), Mozambique
(1990, fuelled with cashew nut husks), Ghana (1989, fuelled with residues and chopped
wood) and Tanzania (1990). In 1994, the stove was adjusted in refugee camps in Uganda to
burn straw, bundled and packed vertically into the unit, ‗without problem‘, which gave it the
vernacular Acholi name ‗PekoPe‘.
In all the countries the stoves were locally made by local tinsmiths with their existing tools
from the materials they could get, either new sheets or scrap metal. The artisans needed
only some guidelines, a template and customers for this simple technology.
At a Trade Fair exhibition in Kampala 1997 they were selling 500 stoves in two days at market
price, at that time 5 US$. Over 5,000 units were in use by 1999, when Paal left Uganda
for medical reasons. Because he developed the technical aspects but not the business side
in the refugee situation, the ‗stove business‘ did not carry on, though the design has great
business potential. The stove was introduced in Zambia in 2008 fuelled with chopped wood.
At Aprovecho Stove Camp 2009 Paal made a PekoPe from a 3 litre tin and some leftover
sheets: The combustion chamber had a diameter of 150 mm and was 180 mm high. Other
features (according to an email posted on the stoves-listserv in December 2010):
55 mm free space from concentration lid up to the pot
105 mm hole in concentration lid