Design and Development of a Natural Draft Biomass Gasifier
R. Krishna Kumar February 28, 2009

Naturl Draft Gasifier - KumarNatural Draft Gasifier - Kumar


  • Operates under the principlle of “ Chimney Effectt ”
  • Natural draft caused by density difference


  • No blower is required for the operation
  • Automatically takes the required quantity of air for Gasification
  • Convey the Producer Gas formed by Gasification - Naturally
  • Reduced fuel consumption compared to traditional chulas

More detail, schematic pictures and testing information are in the attached pdfs and in the 2004 discussion:

Stovetec(tm) Greenfire Technology (tm)
Plain One door
Plain One door

StoveTec™ introduces
GreenFire Technology™
Wood and Charcoal Stoves

Envirofit and BP Stoves
Tom Reed, www.woodgas.com, August 29, 2008
Envirofit and BP StovesEnvirofit and BP Stoves

On Fri, Aug 29, 2008 at 6:38 AM, Thomas Reed wrote:
Dear Stovers:

I am attaching [the image above]that may be of interest to the stovers.

Here is an unsolicited commentary on our new XL WoodGas Stove, available at

Woodgas stoveWoodgas stove
along with our gasification books.

We have recently learned that BP is manufacturing a VERY similar stove
and selling them (only in India) in their equivalent of Walmart. I hear
they have already sold 100,000. Sounds like we are well on the way to
getting a "Billion Improved Stoves" out to the developing world.

If you cover the combustion air holes with aluminum flashing or sheet
metal screws the stove also makes a good gasifier.



The forgotten ‘victim’ of the northern Uganda war
Gladys Oroma, Daily Monitor Only, Uganda June 4, 2008, http://www.monitor.co.ug

In times of war, what concerns people most are the effects of the insurgency on the people, not its effects on the environment among others things.

The war however, in northern Uganda has had severe effects on the environment, says a new report. Due to the conflict, there has been a change in the land cover over the last 18 years. The remote sensing analysis report shows that small-scale woodland covers have increased in the area in the past years.

According to the 2005 report, the woodland vegetation cover increase occurred in the districts of Kitgum, Gulu, Pader, Adjumani and Moyo while a significant decline in the woodland cover was registered in the districts of Apac, Kotido, Lira and Moroto.

Charcoal Producing Microgasifier
Robert Flanagan, SAFFE, China, July 2007

This is a simple way to convert fibrous material with moisture of less than 25% to clean energy and charcoal or Carbon Negative Energy!!!

MJA Biomass Gas Stove
Alexis Belonio, July 23, 2008
MJA Biomass Gas StoveMJA Biomass Gas Stove Burning Coal

Alexis Belonio writes (edited and annotated by Paul Anderson and Tom Miles):

Attached is a picture of my latest coal gasifier stove. This
is the same basic TLUD stove I have for wood charcoal and wood chunks.

For domestic use, I use carbonized coal (or coke) as fuel instead
of the raw coal. Coal can be used for the stove, but we don't want to promote
this as a fuel since it emits poisonous gas. I would prefer to use coal for
industry application where gas can be cleaned before it is released to the

I provide only a small amount of coal fuel in the gasifier stove, enough
for cooking. This mean that the power output is only small and the
metal I use is a stainless steel.

I ignite the carbonized coal by using a wood charcoal that has been soaked in
kerosene as igniter. [This is a TLUD stove, so ignition is at the top.]

[In the Belonio TLUDs, the fan only blows the primary air. The
secondary air is
pre-heated as it rises naturally between the fuel cylinder and the outer
cylinder, finally exiting into the rising flow of combustible gases.]
The smoke in the coal gasifier I have was eliminated [combusted] by mixing
preheated air with the gas generated from the reactor. I think
there is no need of [forced] mixing the secondary air by creating turbulence
with the combustible gases. Because in that case, you will need a
slightly bigger fan with enough pressure to push the air.
MJ Biomass Gas StoveMJ Biomass Gas Stove

Alexis Belonio

Peko Pe Stove, Fuels, Charcoal vs Firewood
Paal Wendelbo, Norway, paaw@online.no, June 2008
Peko Pe L and Peko Pe S
Click image to enlarge

Wood-Charcoal: Two Door Rocket Stove
Dean Still, Stoversource, May 2008

Dean Still shows the new two-door rocket stove designed by Aprovecho Research Center and being made in China.


Wood Pellet Camping ad Biofuel Stove
Deris Jeneatte, Cleardome Solar, april 2008

Here's a stove and solar appliances for the camping set. Some concepts may apply to cooking stoves.

Testing Results of the Ecocina Cooking Stove from El Salvador
Nordica MacCarty, Aprovecho Research Center, March 5, 2008
Nancy Hughes, Stove Team International, April 5, 2008
La Disminuicion de las Emanaciones de HumoLa Disminuicion de las Emanaciones de Humo


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