Pyrolysis is the chemical decomposition of organic (carbon-based) materials through the application of heat. Pyrolysis, which is also the first step in gasification and combustion, occurs in the absence or near absence of oxygen, and it is thus distinct from combustion (burning), which can take place only if sufficient oxygen is present. Pyrolysis produces solids (char), condensable liquids (tar), and uncondensing/permanent gasses. Pyrolysis has numerous applications of interest to green technology. pyrolyzing biomass (biological materials such as wood and sugarcane) holds great promise for producing energy sources that could supplement or replace petroleum-based energy.