Overall mechanism of JP-10 pyrolysis unraveled by large-scale reactive molecular dynamics simulation

Abstract

This paper reports the overall reaction mechanism of JP-10 pyrolysis obtained in large-scale reactive molecular dynamics simulations employing the force field of ReaxFF CHO-2008. The C<5 products obtained from the simulations are basically consistent with what detected using varied experimental techniques reported in literature. Particularly, the product evolution tendency of methane, ethane, ethylene, propylene, acetylene, allene,1−butene, propyne, 1,3-butadiene, cyclopentadiene with temperature is in good agreement with the results of single-pulse shock tube experiment performed in this work. The simulation results indicate that JP-10 pyrolysis reactions can be divided into three stages on basis of the evolution of total radicals, namely, the initial ring-openning through CC bond homolysis in stage I, the initiation and growth of chain radicals through β-scission reactions as well as some of the chain propagation via CH bond scission in stage II, the chain propagation through CH bond cleavage and the chain termination reactions in stage III. The C5H7• and C3H5• radicals were found playing dominant role in the reaction propagation. The obtained initial reaction sites of JP-10 pyrolysis are ranked as: B3>B4>B2>B5>B1>B6>B7 that will not be significantly affected by temperature. The obtained aromatic hydrocarbons in simulations and the increasing C/H ratio with temperature and time during the three pyrolysis stages exhibit the coking tendency during JP-10 pyrolysis.