Technical Note SB85: Pyrolysis of biomass

The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements pyro "fire" and lysis "separating".

Pyrolysis is most commonly used in the treatment of organic materials. It is one of the processes involved in charring wood. In general, pyrolysis of organic substances produces volatile products and leaves char, a carbon-rich, solid residue. Extreme pyrolysis, which leaves mostly carbon as the residue, is called carbonization. Pyrolysis is considered the first step in the processes of gasification or combustion.

Just about any organic waste, whether animal or plant based, may be fed into a pyrolysis machine and decomposed by heat. The trick to deteriorating the waste at high temperatures and not having it catch fire is the exclusion of oxygen. Without fresh oxygen, nothing burns, so that the feedstock separates into separate products. The products can be sold or employed in other processes.