Pyrolysis
The thermal decomposition of a substance at high temperature in the absence of oxygen.
Formula / equation
complex → simpler fragments (Δ, no O₂)
Unit
°C
In depth
Without oxygen the material cannot burn, so instead its bonds fracture into smaller molecules, gases and a carbon-rich char. Pyrolysis of long-chain hydrocarbons, called cracking, converts surplus heavy fractions into petrol and alkene feedstocks for the polymer industry.
Examples in the real world
Cracking decane into octane and ethene; converting wood into charcoal; producing bio-oil from agricultural waste.