Pyrolysis of six nonconventional fuels has been studied by means of nonisothermal thermogravimetric analysis from low (5 degreesC/min) to high heating rates (as large as 900 degreesC/min). The fuels tested included plastics, rubbers, and ligno-cellulosic materials, namely, polyethylene, poly-(ethylene terephthalate), scrap tires, ebonite, a fresh biomass, and waste wood. A kinetic expression for pyrolysis is provided for each material. The mechanisms of thermal degradation are discussed in order to underline differences and similarities between materials.