[السيدمحمدالسيدأحمد]

Pyrolysis
Pyrolysis is a thermochemical decomposition of organic material at elevated temperatures without the participation of oxygen. It involves the simultaneous change of chemical composition and physical phase, and is irreversible
photolysis
a chemical reaction in which a chemical compound is broken down by photons. It is defined as the interaction of one or more photons with one target molecule.