A Wood-gas Stove for Developing Countries

Through the millennia wood stoves for cooking have been notoriously inefficient and slow. Electricity, gas or liquid fuels are preferred for cooking when they can be obtained. In the last few decades a number of improvements have been made in woodstoves, but still the improved wood stoves are difficult to control and manufacture and are often not accepted by the cook. Gasification of wood (or other biomass) offers the possibility of cleaner, better controlled gas cooking for developing countries. In this paper we describe a wood-gas stove based on a new, simplified wood gasifier. It offers the advantages of “cooking with gas” while using a wide variety of biomass fuels. Gas for the stove is generated using the “inverted downdraft gasifier” principle. In one mode of operation it also produces 20-25% charcoal (dry basis). The stove operates using natural convection only. It achieves clean “blue flame” combustion using an “air wick” that optimizes draft and stabilizes the flame position. The emissions from the close coupled gasifier-burner are quite low and the stove can be operated indoors.