pyrolysis

n. chemical change brought about by exposure to heat

Pyrolysis is the chemical decomposition of organic materials by heating in the absence of oxygen or any other reagents, except possibly steam.It is used in chemical analysis to break down complex matter into simpler molecules for identification, for example by pyrolysis gas chromatography mass spectrometry.Industrially, it may be used to convert one single chemical, for example ethylene dichloride is pyrolysed to vinyl chloride to make PVC. It may also be used to convert complex materials such as biomass or waste into substances which are either desirable or less harmful.
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Noun
1. transformation of a substance produced by the action of heat
(hypernym) transformation, transmutation, shift

n. pyrolysis, chemical change brought about by exposure to heat

Decomposition of a chemical by extreme heat.