Thermal property values such as specific heat, thermal conductivity,
and emissivity vary with moisture content, temperature, and
degree of thermal degradation by one order of magnitude. Thermal
degradation products of biomass consist of moisture, volatiles,
char, and ash. Volatiles are further subdivided into gases such as
light hydrocarbons, carbon monoxide, carbon dioxide, hydrogen
and moisture, and tars. The yields depend on the temperature
and heating rate of pyrolysis. Some properties vary with species,
location within the biomass, and growth conditions. Other properties
depend on the combustion environment. Where the properties
are highly variable, the likely range of the property is given [21].