Molecular dynamics simulation on generation mechanism of water molecules during pyrolysis of insulating paper

Reactive molecular dynamics was introduced to simulate and study the mechanism of H2O formation on the pyrolysis process of insulating paper using reactive force field (ReaxFF). Models consisting of fifteen cellobiose molecules were built for ensuring the reliability of simulation result. Simulations were performed at 1600 K, 1800 K, 2000 K. Multiple simulations were carried out to facilitate statistics. In the pyrolysis process, a large amount of H2O molecules generated. The dehydration reaction was divided into three ways: (a) H captured by secondary alcohol hydroxyl; (b) H captured by the O atom of ether group; (c) H captured by primary alcohol hydroxyl. The most frequent turned out to be (a). And the number of H2O generated by the two other pathways was similar. H2O molecules continued to increase with the reaction time and the higher the temperature was, the more H2O molecules were. Simulation result was in good agreement with relevant experimental results and could provide a reference for analysis of overheating fault on oil-paper insulation and fault prognosis of transformer.