The process of thermal decomposition of organic materials (carbon based materials) at very high temperature and absence of oxygen is known as pyrolysis.
The temperature for such process is generally 430 °C or 800 °F. This causes simultaneous change in physical phase and chemical composition of the organic material. The process is irreversible in nature.
The resultant products mostly have more useful properties than the original one. Thus, to bring the greater value to the common organic material and waste, the idea of pyrolysis is important.