Biomass Combustion, Chimneys & Hoods

Biomass combustion is at the heart of a stove programme. The cooking stove is generally the most important component of the household energy system and more efficient, cleaner burning of woodfuels and agricultural residues offers a major opportunity to improve the living and working conditions of poor women.

For the first ten years or more of improved stove programmes fuel efficiency was pursued, open to the exclusion of other important aspects of the work. This proved an elusive goal and as a result stove programmes achieved little success and were questioned by funders. This lesson has been learned and much progress has now been made in improving the socio-economic orientation of stove and household energy programmes and in recognizing the key role of women.

However, our understanding of the basic issue of stove efficiency must be improved. Incomplete combustion is a waste of energy and we now know that the resulting effect on global warming of high emissions of CO particulates and hydrocarbons gases is about equal to that of CO2 emissions. Cleaner and more efficient combustion, better smoke removal and simple methods of measuring pollutant emissions and levels are urgently needed. This edition of "Boiling Point" is concerned with the fundamentals of biomass combustion and ways in which stove efficiency can be improved and harmful pollutants can be reduced by chimneys or hoods. We have endeavoured to bridge the gap between simple explanations of combustion theory, which are often inadequate as a basis for further developments and the more detailed theoretical papers which tend to be unecessarily complex.