Reaction mechanism of polyethylene decomposition in supercritical water

Under supercritical conditions, polyethylene(PE) decomposition experiments were conducted in a batch reactor, and the reaction mechanism and effects o l supercritical water were examined. According to analysis of experimental data, the mechanism of PE decompositi on is based on random break of carbon-carbon(C-C) bonding. During C-C break ing, PE molecules are decomposed into small oils molecules which contain pa raffin and olefins, and then aromatic compounds are produced by polymerizat ion of olefins. NMR measurement showed that hydrogen of H2O is incorporated into the products under supercritical condition of water. A fundamental model of PE decomposition is proposed, and its performance is discussed by comparing calculations and experimental data. Additionally. r eaction rates of coking are evaluated as quite small compared with PE therm al degradation.