Pyrolysis is an engineered process designed to thermally decompose organic polymers, such as plastics, without the presence of oxygen. This is accomplished by heating the plastics to a high-temperature regime—usually in the range of 300 to 700 degrees Celsius—within a specially designed reactor that provides a controlled environment to facilitate the breakdown of complex molecular chains into simpler compounds.

The process selectively breaks the long-chain molecules of the plastic into shorter hydrocarbon chains. The result is the production of a variety of smaller molecules, primarily in the form of combustible gases, condensable liquids (commonly termed pyrolysis oil), and a solid carbonaceous material known as char or biochar.

Chemcycle, pyrolysis serves as a pivotal technology for converting plastic waste, which is typically resistant to biodegradation and challenging to process mechanically, into valuable synthetic crude oil.