Cooking the Planet: Are biomass stoves in the developing world affecting climate change?
Jeremey Roth, Aprovecho, January 2008


VIDEO: How to build a Rocket Stove (includes making insulative refractory bricks)
Jeremy Roth, Aprovecho Research Center, June 12, 2007

A new video from Aprovecho showing step-by-step instructions for building a small, single-pot rocket stove made from sheet metal and insulative refractory bricks. Instructions for making refractory bricks are also included in the video.

The video is available for viewing and download from Aprovecho's website www.Aprovecho.org

See http://www.aprovecho.org/web-content/media/rocket/rocket.htm

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!

Principios de diseño para estufas de cocción con leña
Alianza para Aire Limpio Intradomiciliario (PCIA) 10 julio 2006

La Alianza para Aire Limpio Intradomiciliario (descrito aquí como Alianza o PCIA por sus siglas en inglés, “Partnership for Clean Indoor Air”) fue establecida por la Agencia de Protección del Medio Ambiente de los Estados Unidos y otros socios principales de la Cumbre Mundial sobre el Desarrollo Sostenible en Johannesburgo

Dean Still, June, 2005

download the Insulated Rocket Stove for Charcoal pdf
Preliminary Fuel Use and Emissions Test Results:

    Wood Stove
WFP Wood
(with Skirt)
Time to Boil min - 22 29 22
Fuel to Cook g 850 604 675 733
Energy to Cook kJ 15,000 23,983 26,089 12,579
CO to Cook g 20 12 74 15
PM to Cook mg 1500 81 85 1289

Dean Still and Brad van Appel, Aprovecho Research Center, January 1, 2002

The Effect of Material Choice on the Combustion Chamber of a Rocket Cooking Stove: Adobe, Common Brick, Vernacular Insulative Ceramic, and Guatemalan Floor Tile (Baldosa)

The Search for Vernacular Refractory Materials

Multiple tests of the Lorena stove beginning in 1983 at the Aprovecho Research Center have shown that placing thermal mass near the fire has a negative effect on the responsiveness and fuel efficiency of a cooking stove. In 1996, Leoni Mvungi built a Rocket stove from earth, sand, and clay that was a replica of a low mass Rocket consisting of metal chimney parts. His version weighed hundreds of pounds even though the Rocket internal chimney was only eleven inches high. Tests of a low mass sheet metal version scored around 30% fuel efficiency. But the best result achieved by the Mvungi stove was around 15%.

Building Rocket stoves from sand and clay showed little promise of improving on the three stone fire which was scoring around 18% in repeated boiling tests performed by Jim Kness and Dean Still (1994). Unfortunately, metal stove parts also have a major drawback in that the high heat in the combustion chamber quickly destroys thin metal. Consultants were in agreement that a good stove should last for years without requiring maintenance. Replacing metal parts as they wear out was not considered a viable solution.

A women's co-operative in Honduras (Nueva Esperansa) makes ceramic stove parts that have a reputation for working well in stoves. Aprovecho consultants Mike Hatfield and Peter Scott contracted with this group to produce combustion chambers for the Dona Justa plancha stoves that they helped to design. This material seemed to work well and, in fact, the Rocket elbow made by Nueva Esperansa has been successful in Honduras and Nicaragua. It is difficult, however, to deliver the fragile combustion chambers without breaking them. Also they are relatively expensive, costing about eight dollars each.

Don O'Neal (HELPS International) and Dr. Larry Winiarski have shown that cast iron combustion chambers, which do last, also have problems. Tests showed that the very conductive cast iron made the fire hard to start. In fact, a group of indigenous Guatemalan women stove testers living in Santa Avelina were unhappy with the expensive cast iron combustion chamber and asked for it to be replaced. They wanted a more responsive stove that started quickly, and quickly cooked food in the morning. Don and Larry eventually found an alternative material: an inexpensive Guatemalan ceramic floor tile (called a baldosa in Spanish) which seemed to function well when cut up to make the walls of the Rocket combustion chamber. The baldosa was about an inch thick so the combustion chamber only weighed eighteen and a half pounds. Like all Rocket combustion chambers it is surrounded by insulation, either wood ash or pumice rock.

The baldosa tile has done well in test stoves. It seems to be durable, lasting a year so far, and the group of testers from Santa Avelina reported that their stoves are much improved. The ceramic material made the stove much quicker to heat up. The women approved the improved stove for general dissemination to neighbors and other villages. The HELPS molded griddle stove now uses a preformed ceramic combustion chamber made by a local baldosa manufacturer. Unfortunately, all baldosa are not equally resistant to heat and it's important to test tiles before using them in stoves.

Appreciating that ceramic seemed a promising material for Rocket combustion chambers, Ken Goyer, an Aprovecho Board Member and consultant, spent a year, 2000-2001, testing ceramic mixes. His research resulted in a vernacular insulative ceramic material (VIC) that is refractory, insulative and can be home made. Six bricks made from this material combine to make a complete Rocket combustion chamber. Making the chamber from separate bricks has resulted in a greatly reduced tendency to crack. The bricks have held up so far in durability tests and they seem to create a very active fire.

The purpose of this paper is to describe the results of experiments involving same sized brick combustion chambers made from adobe, the insulative ceramic mix and common ceramic brick material. All bricks shared the same dimensions. Six bricks (11 ½" high by 2 ½" thick) made up a hexagonal cylinder surrounding a four inch in diameter chimney. Sticks of wood entered the bottom of the chimney through a hole sawn in the bricks. A combustion chamber made to similar dimensions was constructed using baldosa tile bought in Guatemala. Vermiculite filled in around the baldosa creating a combustion chamber with approximately the same dimensions as the brick stoves.

Protocols for Standard Stove Tests Using PICO Software

Dean Still, Aprovecho Research Center, April 25, 2008

Dear All,

Stove Camp this year will take place August 4-8 here at the new lab which is on 4 beautiful acres with a nice river on two sides of the property. Folks are invited to camp here near the river! We will cook on wood burning stoves for lunch and dinner and bake tasty bread in a Rocket bread oven. We can have bonfires at night and figure out how to distribute one billion stoves.

Paul Van der Sluis from Philips may be able to attend. Friends in India are trying to buy and send us a BP stove. Can anyone in India assist them? I'll pay costs, shipping, etc.

Pam Baldinger, now in Darfur with USAID, very much supports this year's theme and contest. The team that cooks corn flour using the least fuel, etc. wins the more and more coveted Dr. Kirk Smith Cat Pee Award and $250! The most effective solutions will be sent to Pam.

Let's prove that cooking with wood can be done with very little fuel! It's important! Let's help refugees.

There's room for 25 participants. Book early!

ETHOS Stove Camp costs are:
Instruction/Participation: $100 students $200 others
Camping (5 nights): $25 students $50 others
Five dinners cooked here with wood on Rocket and other stoves: $25



Aprovecho Research Center
Fred's Island
Cottage Grove, Oregon
541 767 0287

Aprovecho research Center, July 18, 2005

Download the full report Stove Performance Report: Mayon Rice Hull Stove

Laboratory Comparison of the Global-Warming Potential of Six Categories of Biomass Cooking Stoves

Aprovecho Mass Producing Stoves
Dean Still, Aprovecho Research Center, September 4, 2007
Officials from Shengzhou Stove and Aprovecho Seal the DealOfficials from Shengzhou Stove and Aprovecho Seal the Deal


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