Tom Miles, ETHOS Conference 2011
Kirkland, Washington, USA January 28th ~ 30th, 2011

The ETHOS Stoves Conference was last weekend, and it included demonstrations by some of the stove makers and manufactures, with the opportunity to talk to the people using and inventing the stoves.

Here are some of the stand-outs from the demonstrations area, click on an image to view it in a larger size.

The Shark Stove presented by John and Flip Anderson. Notice the even cooking on the pancakes, that even heat is partially due the ceramic shark teeth construction just under the cooking surface. This is primarily a stick burning stove with both a plancha (even cooking surface) and pot rests.

Jatropha Seed TLUD (Top, lit, updraft design, using natural draft - no fan) by
Pamoja (http://www.pamoja.net/protree_jatropha.html) and Jet City Stoveworks ( http://jetcitystoveworks.com/ ). Abely demonstrated by David Otto.

Paul Anderson dexterously burning Jatropha seeds (out of doors) in the Woodgas Stove ( http://woodgas.com/bookSTOVE.htm ) designed by Tom Reed. This is a light weight gasifying stove (minus the pot rest in the picture) that uses a small electric fan.
Boiling water in the Charbelle, presented by Peter Scott. The Charbelle is a Charcoal cooking stove designed by the Burn Design Lab ( http://www.burndesignlab.org/our-stoves/ ) for use in Haiti.

This stove features an abrasion and thermal shock resistant ceramic liner surrounded by sheet metal cladding. The stove is currently being mass produced and sold in Kenya. The stove has been very well received, earning top marks from consumers.

Ryan with StoveTec was demonstrating the StoveTec Stove ( http://www.stovetec.net/us/ ) an Ashden Award winning cook stove that can either be used with stick wood or charcoal.

The institutional version of the StoveTec Stove for use in schools and other organizations, has an attached chimney and an a pressure cooker version. The pressure cooker is useful to shorten cooking times, and the fuel consumption, when cooking beans and small grains.

The Nomad PrePac ( http://www.preppac.net/ ) Bio-fuel Camp Stove burning stick wood. This is an ultra-light stove designed to burn small amounts of fuel for camping or for emergency preparedness.

the PEMS emissions testing was happening at ETHOS (of course), Larry Winiarski is in the background in these pictures.

Stove and 1 HP Pelletizer
Brendon Mendonca, Watershed Organisation Trust April 25, 2009

WOTR StoveWOTR Stove
Pictures of the stove (4000 sold) and 1 HP pelletizer.

Following is the link to our website http://www.wotr.org/renewable_energy.html

WOTR 1 HP Pellet MillWOTR 1 HP Pellet Mill

Brendon mendonca.brendon@gmail.com

Marshall Islands Energy Fair--- Stoves March 2009 Michael Trevor, Marshall Islands,March 8, 2009

Firing Things UpFiring Things Up

See slide show attached. I did this in conjunction with a Woman's Club, "Kare in Okrane." Essentially, "Women of the Break of Dawn," a reference to women getting up a the break of day to prepare for the family's day. We did have hundreds of observers and a strongly expressed interest. In this case the rocket stove had the clear edge. Burning fuel is what people understand. Women have been doing it at their grandmother's knee since childhood. The Solar oven probably came in second. Here it was much like a microwave. I had to constantly open it up and invite people to touch the pot. Ouch, that it hot, hey it does work. What can you cook in it? Sadly the TLUD was more of curiosity. . The kerosene/propane like flame did surprise people, and I repeatly brought up charcoal and terrapreta as a benefit over time. However, the small size and short burn worked against it. I simply switch between two to resolve this. Best Regards to all Michael Trevor mtrevor@ntamar.net

Palm Fronds as Fuel in a TLUD (Top Lit Updraft)
Micheal Trevor, Marshall Islands, December 7, 2008

Loaded Chopped FrondsLoaded Chopped Fronds

Remember in the rocket stove I am use very "pulpy" stuff.
In the TLUDS-- XL Woodgas and my tincanium ones--- they make charcoal. As for shell I have not tried it much yet in the TLUDS althought my son burned out the first XLWoodgas unit on it.

I think a mix of broken shell chips with the chopped frond piece may work very well.
The chopped frond pieces work well but the burn is rather short.

In industrial applications like a bakery I am sure shell would be fantastic if you could get enough.I think everyone else would get it first

Michael Trevor
Marshall Islands

Chopped Fronds for FuelsChopped Fronds for Fuels
Light OffLight Off
Nice BurnNice Burn

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.



Dean Still, August 9, 2008

How to Use a Woodgas or Smoke Burner Stove
N. Sai Bhaskar Reddy, July 1, 2007


Smoke Burner Stove - MAGHSmoke Burner Stove - MAGH

The Woodgas or Smoke Burner Stove technology is new to many users. These are the most efficient Good stoves, with a choice of using different types of available biomass.

Summary of Aprovecho’s Summer Stove Camp, 2006
By Dean Still and Nordica MacCarty, September 6, 2006

Aprovecho Camp 2006 02Aprovecho Camp 2006 02

Stove Camp 2006 was extremely interesting, especially because we had experts here who could help define what is known, figure out what needed to be done to expand the state of knowledge, and then, most importantly, have the tools to accomplish the experiments.

For Dean, the best moments happened around the table above when Chris Roden, Jonathan Lewis, the Aprovecho staff and everyone tried to get a general feeling for wood-burning stoves effect on global warming. Aprovecho’s recent tests at CSU of greenhouse gas emissions such as CO2, Methane, N2O, NOx, etc. helped to predict the gaseous emissions from the following stoves:
• Three stone fire
• Rocket stove
• Karve Gasifier stove
• Philips fan stove
• Charcoal Jiko stove
• Mayon rice hull burning stove

The gases, however, are only a part of the picture: particles also play an important role in the atmosphere. We learned that elemental (black) carbon particles produced in flames have a warming effect 1000 times greater than CO2 per gram, while organic carbon (white) particles produced by smoldering have a cooling effect 150-200 times stronger than CO2. Thankfully, Chris Roden had brought his and Dr. Tami Bond’s ARACHNE system which could measure the composition of the total PM to determine what percentage of black or white particles were produced by the stoves above. Chris, Damon and Nordica were at the lab till 11pm having a great time testing these stoves. Results should be available soon.

Doing this kind of research in a small lab in Creswell, Oregon for no money is what ETHOS stove camp is all about!

The publicized theme of this year’s camp was a competition to design the cleanest-burning fan stove. Two categories, side feed and top feed were awarded prizes. The top feed prize went to Dr. Paul van der Sluis for the Philips fan stove. The side feed Rocket stove with fan developed by Roger and Sule of Colorado State was the cleanest burning side feed stove. Congratulations to the winners!

WoodGas vs Wood Combustion
Tom Reed, Biomass Energy Foundation, April 2006

As a longtime proponent (since 1973) of biomass gasification and moderator of the gasification REPP group, let me define "gasification" a little more widely than the discussion below
Coal pyrolysis produces typically 80% fixed carbon, 20% gas and volatiles. The principle step then for coal gasification is getting that carbon to be a gas with either oxygen, CO2 or water

2C + O2 ==> 2 CO
C + CO2 ==> 2 CO
C + H2O ==> CO + H2

The first reaction is exothermic, while the last two are endothermic.
So pass air/oxygen, CO2 and H2O through coal and you produce CO + H2.
Coal gasification was the principle form before 1940 and was practiced at a large scale because of the need to remove sulfur and ash. During WW II however, biomass was the fuel of choice for small gasifiers to run cars, trucks and buses.


Biomass is typically 80% gas plus volatiles plus 20% fixed carbon. So the main problem is to convert the volatiles to CO + H2.

Pyrolysis typically occurs at 300-500C. Conventional bottom lit updraft gasifiers burn charcoal on a grate to produce hot CO-H2 which then pyrolyzes the incoming biomass to make VERY tarry gas. *(I call this a "char burning, tar making gasifier")*.

But if you pass air through a mass of biomass the temperature is 700-1000 C, and we call that "flaming pyrolysis". FP produces mostly CO
+ H2, CO2 and H2O and small amount of condensibles (tars). These then
pass through the remaining charcoal where most of the volatiles are destroyed. At the high end the condensibles are typically < 100 ppm.
At the low end, more like 2000. *(I call this a "tar burning, char making gasifier").
I call the Flaming Pyrolysis process "PYROLYTIC GASIFICATION". It occurs at a continuum of temperatures from 700-1000C, depending on air/fuel ratio. At the low end, 700C, very little of the charcoal is gasified and the toplit updraft stoves produce 5-25% charcoal, depending on the moisture content of the fuel. At the high end up to 1000C the gas is VERY low tar and useful for operating engines for power and transportation and for synthesis of methanol and diesel. .

If secondary air is added to the gases after they are generated you have a very clean and hot flame. This is VERY different from direct combustion and I classify our WoodGas Campstove as a close coupled pyrolytic gasifier and combustor.

We now are selling WoodGas Campstoves at our website store along with our books on gasification (www.woodgas.com) and I recommend getting one and pondering the profound difference between the gasification and direct combustion of wood for cooking. While we have made the campstove, the principles can be applied at all scales for apartment and
field cooking around the world. We hope they will be.

Yours truly,

The Biomass Energy Foundation


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