Improved Biomass Cooking Stoves

Example Measurements of the Moisture Content of Biomass Charlie Selllers, March 27, 2009 Perfectly dry biomass would be a boon for stove testing (and for use by cooks around the world) but it is rarely available – therefore we should at least know what our moisture content is so that we can estimate how much of our energy we are using up boiling it, instead of having it available to work with. After seeing Tom Miles’ post on the standard procedure for microwave drying of wood (I thought that I developed this in my kitchen a few years ago!): http://gasifiers.bioenergylists.org/milesmccontent Here I dig up some of my own data – I need to know moisture content for preliminary cooking stove Water Boiling Tests (WBT), and it is also one of the major variables when operating biomass gasifiers. Understanding water re-uptake by biomass is important as well – whether it is due to changes in the weather, it occurs after we open a new bag of wood pellets to be used for baseline testing, we needed to move our supply from one place to another, or because we have gone to all the trouble of using producer gas to dry fuel but don’t have time to burn/gasify it for a few days. See report attached.

Paul Anderson, March, 2009 How many of each major type of cookstoves exist in the developing societies(functioning in 2009)? The attached "draft" Matrix gives you my guesses. Perhaps YOU have additional input. Maybe we should change the Matrix. More columns, more lines. Or do you agree with what content? What I am attempting is to get us all reasonably "on the same page", literally on the same single page. Please look carefully at the two Notes at the bottom. In the general rank ordering, any stove type (or specific stoves within a type) might be shifted one or two columns to the left or right. But the question is, are the notes and orderings reasonably correct? There is no right or wrong, best or worst. By sheer numbers of units, the 3-stove fire is "best." It literally is "the competition to beat" for all of the other stoves. The file is an active MS Word document ( .doc), so you can change it as you please, but please indicate that you have altered it. (I desire neither the glory nor the blame for what you contribute.) It is a very small file and might be distributed with this message.

Paul Anderson, March, 2009

I. Proposal:
“Air-controlled” biomass cookstoves should be seriously examined as viable replacements for charcoal cookstoves in urban and peri-urban communities in developing societies.

II. Situation, Problem and Opportunity:
Throughout the urban areas of developing societies, charcoal cookstoves have an important role in
residential cooking (including other small-scale cooking in restaurants and institutions). The acceptable energy sources for urban cooking are charcoal, LPG, kerosene, alcohol, and electricity. (Solar cooking is omitted because of housing densities and shadows.) All of them require significant “conversion” from their natural sources, and are deemed to be sufficiently clean energy, meaning a “lack of bothersome smoke” or very low emissions of particulate matter (PM).
Charcoal competes well against those other high-order heat sources because it is easily and relatively inexpensively made from wood and other dry biomass by unskilled labor. But charcoal has two major drawbacks: A) very high levels of carbon monoxide (CO) emission; and B) the destruction of local vegetation from which the charcoal is made. Therefore, it is important to examine viable alternatives such as modern cookstoves that efficiently combust raw dry biomass such as wood which yields CO and PM emissions (“smoke”) even lower than those of charcoal stoves. If these new stoves are successful, task-appropriate, and sustainable for urban cooking, they will also significantly reduce the problems of deforestation and greenhouse gases while providing urban residents with economical and convenient fuel alternatives.

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

Firing 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

Construction Plans for the “Champion-2008” TLUD Gasifier Cookstove (including operational instructions) Paul Anderson, March 1, 2009

TLUD

The document attached contains detailed instructions for the construction of Anderson’s "Champion-2008" top-lit updraft (TLUD) gasifier that can be used in many different cookstove structures. On 18 pages with 39 Figures, the “Champ” is described in three versions (Hobbyist, Refugee and Artisan) with the same dimensions but using different materials and metal-working skills.

BP Arivi Paraffin Stove

February 2009

BP Arivi Paraffin Stove
BP Arivi

BP has taken a life-cycle approach, starting with the consumer need, through to regulatory and HSE assessment in the case of BP Arivi. BP Arivi is a low-sulphur paraffin fuel for domestic cooking, providing consumers with access to an affordable, high-value fuel, in safe and child-resistant packaging. Different options were considered to determine the most appropriate fuel to meet the needs of consumers and scrutiny of the supply chain was undertaken to identify key risks We are now commercially piloting this solution in the market in South Africa and there will be further iterations around the process. (Website www.myarivi.com)

Other BP Arivi Links

Designer - Terrestrial ( www.trstrl.com ) Arivi Stove

• Index Design Award

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

Natural Draft Gasifier - Kumar

N D G - BASICS & PRINCIPLES

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

UNIQUE FEATURES COMPARED TO CONVENTIONAL SYSTEMS

• 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:
http://www.repp.org/discussiongroups/resources/stoves/kumar/ndg.htm

Finned Pots as a Means of Increasing Efficiency Dale Andreatta, Ph.D., P.E., dandreatta@sealimited.com, February 13, 2009

Finned Pot

Executive Summary A pot with heat transfer fins has much greater surface area than pots with no fins. In theory, this could lead to greatly increased heat transfer to the pot for a given stove, and the pot would theoretically improve the performance of the stove under all conditions. While we often concentrate on the stove as the primary element of a cooking system, the efficiency of a stove is mainly determined by the heat transfer to the pot, and designing a better pot would be an easy way to make a more efficient stove. A variety of types of finned pots were built and tested. The best designs were separated out in the lab, using natural gas to simulate a wood flame. Several types of fins can be retrofit to existing pots. The better designs of finned pots performed well over a range of conditions using simulated stoves, and sometimes also with an actual wood burning stove modified to use natural gas to simulate a wood flame. With fins on or near the bottom of the pot the finned pots typically gave around a 1.76-fold improvement in heat transfer. If the fins were on the sides of the pot a greater than 2-fold improvement was achieved. Tests on actual stoves using wood as the fuel generally gave smaller improvements in performance, generally 1.33 or less, corresponding to a 25% or smaller reduction in fuel usage. These tests were done under a variety of conditions with a variety of stoves, including the open fire (3-stone fire). On industrial fuel stoves using kerosene or alcohol, improvements were even less, with the finned pots giving 1.2 fold improvements or smaller. In some tests the finned pot used more fuel than an unfinned pot. The reasons for this wide range of results is not known. It is not recommended that finned pots be pursued as a means of increasing the efficiency of stoves. Better results can probably be achieved with less effort by using skirts around the pot. These skirts could be attached to the pots with optimum dimensions. See attached report presented to ETHOS 2009

INTRODUCTION
Ecological responsible projects run by VOICES FROM THE FOREST, a sustainable resources business consortium in Nigeria. The projects; which are open to collaboration include developing interactivity and organic fuels for cooking stoves and bush regeneration.
Backgrounds to the projects as well as results from experiments carried out by the consortium are also included in the project.

(More information is included in the attached files).

Danke Schon
Merci
Thank you.

Akin Olatidoye,
Media and Market Research
Spectra Nova Copy And Design Services

The Belizean Justa Stove
A Step by Step Construction Guide in English and Spanish
Sebastian Africano for Trees water and People, February 2009

Attached are pdf files of the guides in english and Spanish.

Click on the images below to expand, and then click on "Original" for detail.