Mike Barbee, January 2012

Jatropha curcas is grown as a living livestock corral and as a bio-fuel crop in several areas of the developing world. The seed from the Jatropha plant, as well as the oils are toxic to animals and to people. Ingestion, or skin contact with the oils of the plants, leafs and seeds is known to be toxic, and Mike does a nice job of documenting the current research about the plant in his paper: Summary of Literature on Jatropha Toxicity

It appears that there is NO RESEARCH on the toxicity of Inhaled jatropha either seed, stem, or cake (or pressed cake) form. This is an area of particular concern for me as we evaluate the effectiveness of using Jatropha as a fuel for cooking stoves.

to quote Mike:

There are no studies about jatropha the fraction of phorbol esters that may be present during pressing, composting, or burning. There is not enough information about the volatility to estimate the partitioning of oil that may contain esters in the air during the processing and application

The Key recommendation:
"It is recommended at this point, that those who are working directly with oil and seed cake during the pressing process wear protective eye and skin covering and, if possible, surgical masks to reduce inhalation."

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.

Bjarne Laustsen, January 2010, update November, 2010

Jiko Mbono is Swahili for Jatropha Stove.

This is an early version of the stove, it is now using That stove was an early prototype. It is no longer using whole seeds but instead pellets made from the pulp left over after the pressing of jatropha oil, although there is only one pelletization facility for this in Tanzania and no distribution arrangements. Now only, the Jiko Safi uses whole seeds.
The idea is to plant jatropha as a hedge around land holdings. Animals won’t eat it and around an average holding it produces enough seed for a family’s annual fuel needs. I agree that planting it as a crop isn’t ideal


Jiko Mbono was developed for burning whole Jatropha seeds.
The stove is a TLUD (Top-Lit UpDraft) gasification stove with natural draft air supply.

Earlier development of Jatropha stoves have mainly been based on the use of Jatropha oil. But the use of Jatropha oil in stoves have had some problems. In wick stoves the problem have been on the high viscosity of the oil which makes it difficult to climb wick to feed the flame, this has caused the wick material to burn. Jatropha pressurised stoves have also the problems of keeping the nozzles clean, and also the complicated design which tends to make the stoves relative expensive.

I therefore got the idea to burn the seeds directly in the stove. If the gasification process could provide the heat in the stove to vaporize out the oil from the seeds in the form of gasses, that will save us the work of first mechanically pressing the oil out of the seeds.

I therefore started some experimentation with some simple stove design, and these first experiments showed that it was possible to burn the whole seeds in a stove. Further developments was however needed to get an efficient and user friendly design of the stove.

I contacted Dr. Hassan M. Rajabu from College of Engineering & Technology at University of Dar es Salaam so that we could further develop the stove and test the stove after each modification. In this development we have received valuable economical support from the US based organisation Partners for Development and also support from Pamoja INC. Engineer F. Lauwo from Tanzania Engineering and Manufacturing Design Organisation (TEMDO) have provided assistance in producing the prototypes of the stoves.

Diagram of Jiko Mbono.

The fire in the stove is normally started by having a few crushed seeds that are soaked in methylated spirit or kerosene. These crushed seeds are placed at the top of other seeds in the fuelbox and the fire is lit in these crushed seeds.
The initial process can be started inside the stove or outside. When some seeds at the top got good flames (3-5 minutes) the fuelbox is then placed on the shelve at the bottom of the stove door and the door is closed so the fuelbox get into its position in the centre of the stove. In this initial phase the primary air is kept fully open.

The pyrolysis of the seeds by supply of primary air will gradually build up and the gasses from the pyrolysis will raise by the draft from the stoves internal chimney and be burned at the top by mixing with the secondary air.

During this gradually build up of heat the primary air supply need to be reduced such that enough secondary air can be supplied to allow for a good combustion of the gasses.

The burning of the Jatropha seeds is undertaken in batch portions. After all the seeds in the fuelbox have been pyrolysis the fuelbox need to be taken out and refilled for a new burning. It is not possible at this stage of the development of the stove to refill the fuelbox when the stove is operating, such refilling will just results in heavy smoke.

With a full load of fuel 300 – 400 gram of Jatropha seeds the stove can burn for 1 to 1½ hour when used in real cooking where the fire is somehow turned down. During test we have recorded specific fuel consumption on around 52 gram seeds per liter of boiling water, and an energy efficiency around 44%. However, the high efficiency is atributed to the design of the top part of the stove where the top is inserted in a skirt.

When operated properly the carbon in the seeds will remain as some kind of charcoal.

The use of renewable fuel is important here in Tanzania, where most of the biomass fuels are harvested in natural forests which takes year to re-grow.
We have estimated that a household having 200 – 300 meters of hedges of Jatropha trees will be able to meet their own need of fuel for the household cooking. Jatropha is often planted as hedges, it is a good hedge plant, as it is not browsed by goats, cows or other animals. Also as a hedge plant it does not compete with food crops on cultivating areas.

For urban households in Tanzania Jatropha is a viable alternative to charcoal. A farmer here gets 150 Tsh for one kg of Jatropha seeds (exchange rate 1350 to $). In town the Jatropha seeds will sell for around 300 sh. An urban household will need around 2 kg seeds per day to meet their energy need for cooking, that gives a monthly energy bill of 18,000 sh. If the same households are using charcoal it will on average consume 3 bags of 30 kg charcoal of a price of not less than 15,000 sh, this gives a monthly energy bill of minimum 45,000 sh. The use of Jatropha will in this way represent a good saving and alternative to fuelwood and charcoal.

Other seeds and crop wates can also be used in the stove. We know that seeds from the Croton tree burns well so does Castor seeds. We have also tried and found that the shells from cashew nut burn well in the stove. These shells are mainly a waste product from small-scale Cashew nut processing plants which are scattered in regions growing cashew trees.. We also believe that other seeds such as the oil palm kernel could also burn well when cracked a little. There will likely be many other oil holding seeds that could be used in such a stove.

ARISTO. The Plant oil stove
Yun Ho Chae, Grupo Ari SA, Santo Domingo, Dominican Republic December 3, 2008

Two Burner ARISTO StoveTwo Burner ARISTO Stove

With the purpose of developing a stove that uses a different fuel to petroleum and other conventional, 4 years ago was initiated the development of an alcohol stove, which presented several problems in its efficiency such as:

A. Under performance in the generation of heat energy
B. High cost of fuel (alcohol)
C. High levels of evaporation of alcohol, which generated a minor use
D. Smell of alcohol due to its evaporation
E. Danger in use because of the high level of inflamability of alcohol in their natural state

With these results has been decided to seek other fuel that could solve these problems.
During 4 years we have researched and developed a stove that is capable of generate the same or better performance that gas stoves have and could solve the drawback of accessibility to gas in rural areas and areas far from cities.
To that end we developed a stove that works with vegetable oil, whose characteristics are presented below.

3. Description

Aristo is a 2 stove burners that operates using all kinds of vegetable oil.
The most known types of oils are Higuereta, jatropha, Camelina, African palm.
They can also be used cooking oils made of soybean, maize, sunflower, although these are not desirable because of its high cost and are also products consumed at home.
Another excellent option is the use of used cooking oil, which has a high performance at low cost.
The stove oil has a good performance on fuel consumption.
Compared with the gas generates a decrease of 40% in costs

Features and Benefits

1. Easy to use and fast ignition
2. High level of heat energy
3. Danger void, because the oil only lights inside the stove
4. Do not emit toxic gases.
5. The oil is not volatile, so you do not need special packaging
6. No need of heavy and expensive storage tanks
7. The oil can be obtained at any point of sale, in small packages
8. In the fields can be sown to extract oil for own use
9. It reduces the import of liquefied gas which would generate large benefits to the country.
10. They can be used as heaters in cold regions.
11. This produces a savings of up to 70% in costs compared with gas.
12. It helps preserve the environment by reducing the felling of trees used as firewood for cooking.
13. The oil stove is much more economical than a gas stove.

For more information contact to:
Grupo Ari SA, http://grupoarisa.com
email: ychae13@yahoo.com
Tel: 1-809-975-4675

See videos on the following links:

1.You tube: Aristo Demostration


2.You tube: Aristo Introduction


History of the KAKUTE plant oil stove
Jonathan Otto, Pamoja Inc., September 12, 2006

Vegetable Oil Stove
Erik Jan Rodenhuis August 16, 2006
Volunteer at Working Group on Development Techniques (WOT), Enschede, The Netherlands

The PROTOS Plant Oil Cooker
Samuel N. Shiroff, BSH Bosch and Siemens Hausgeräte GmbH, Munich, Germany, April 24, 2007
Protos CookerProtos Cooker

India: Centre for Jatropha Promotion http://www.jatrophaworld.org
Society for Rural Initiatives for Promotion of Herbals (SRIPHL )Churu, Rajasthan, India

GTZ Probec Protos Stove Tests Tanzania
Christa Roth, GTZ Probec, September 26, 2006

To give feedback on the Bosch-Siemens PROTOS plant oil stove when using Jatropha oil:

To give feedback on the Bosch-Siemens PROTOS plant oil stove when using Jatropha oil:
The long term test of the Jatropha oil being used in the BSH stove is currently under way in Tanzania in cooperation with GTZ-ProBEC. Preliminary tests are giving very positive results, even though with Jatropha oil being produced on small scale. Purity of the oil seems to play a crucial role, but we will be able to tell more early 2007.
The stove is designed for using straight plant oils, no need to convert them into Biodiesel. However, Biodiesel can also be used.


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