DB: Paul, in retirement you now devote most of your time to the development of an efficient and affordable cooking stove for homes in many parts of the Third World. We want to hear more about this social entrepreneurship.
PSA: In 2001, when I witnessed a demonstration by a world expert on "gasifiers", I immediately realized the tremendous potential of this new method of combustion for stoves in developing countries, and for the past four years I have worked to perfect this type of stove. Nearly two million people die each year from smoke inhalation in huts and other dwellings in the Third World. Most of these people are women and small children who spend much of their time near the family hearth. In addition, this type of combustion utilizes fuel that does not require cutting local forests.
DB: Explain to us what a "gasifier" stove is and why it is potentially so important in the Third World.
PSA: All stoves can be characterized by 1) the fuel utilized; 2) the type of combustion used; 3) possible applications for the heat produced; and 4) features such as size and cost. At this time I am concentrating on the combustion technology and the fuels that can be used. The gasifier stove utilizes almost any dry, chunky fuel such as wood chips, bark, corn cobs, palm fronds, etc. to produce heat in the following manner. In the first part of the process the fuel is top-lit and is progressively "pyrolyzed" downward in the fuel cylinder of the stove which produces the traditional gases in the form of smoke. However, the smoke is promptly combusted by a secondary source of air that is introduced into the upper part of the stove. These gases produce an intense heat without any smoke. A "co-product" of this TLUD (top-lit up-draft) combustion is charcoal that can also be used for fuel. The job of such a stove is that it can operate using a multitude of "trash" fuels without producing unhealthy pollutants in the form of smoke and other gases. Another important benefit of a gasifier stove will be to reduce deforestation.
DB: Tell us about the problems that are encountered in developing such a stove and seeing it used on a large scale.
PSA: I have build more than 100 variations of the gasification device attempting to solve various problems. Most of them are concerned with obtaining the delicate balance between the creation of the smoke and the introduction of the correct amount of secondary air to achieve complete combustion from ignition to the end of the burn. Another major issue is that the equivalent of the materials and techniques I use here in Illinois have to be readily available at minimal cost in the developing societies. Remember, most of the families that need these stoves normally have less than $2.00 per day of total income. We hope to ultimately produce a minimal stove for as little as $5.00. Recently, I returned from Bolivia, where I am now concentrating my efforts and where I plan a pilot introduction. To make sure that I use fabricating materials that are available there, I returned with a large suitcase of recycled tin cans that are abundant and cost very little.
DB: You plan to visit Bolivia several times in the next year or two. On what other problems will you work?
PSA: First, I hope to get many, even hundreds of users started with the pilot model. We must see that they learn proper use of the stove, are appraised of safety issues, and that it compares favorably with traditional methods of cooking. The stove must be finely tuned for satisfactory performance in different environments ranging from lowland jungles to the frigid Altiplano and with the different fuels that are available in these areas. Other application issues to be considered include family size, type of cooking utensils available, and methods used in preparing food. Thus, the introduction of this new technology will require people possessing different expertise to participate in the refinement and operation of the stove.
DB: The problems to be confronted seem daunting, but the possibilities seem tremendous. How would you summarize the potential of this work?
PSA: The benefits of a stove that does not pollute, doesn’t contribute to deforestation, and improves living conditions for families are difficult to overstate. Thus, I plan to work with governmental and non-governmental agencies, medical workers, foresters, and also private enterprise. I would love to have various people from ISU also involved in this project.
— This story was written by Dale Birkenholz, Professor Emeritus of Biological Sciences and first appeared in Renaissance Retirees, an annual newsletter dedicated to showcasing the College's emeritus faculty.