
229Capturing Solar Energy through Biomass
© 2008 Taylor & Francis Group, LLC
4.2.4.1 Direct Combustion
Combustion is the rapid oxidation of fuel to obtain energy in the form of heat. Since bio-
mass fuels are primarily composed of carbon, hydrogen, and oxygen, the main oxidation
products are carbon dioxide and water although fuel-bound nitrogen and sulfur can be
signicant sources of sulfur oxide and nitrogen oxide emissions. Depending on the heat-
ing value and moisture content of the fuel, the amount of air used to burn the fuel, and the
construction of the furnace, ame temperatures can exceed 1650°C.
Solid-fuel combustion consists of four steps, ...