Initiation mechanisms and kinetics of pyrolysis and combustion of JP-10 hydrocarbon jet fuel.

In order to investigate the initiation mechanisms and kinetics associated with the pyrolysis of JP-10 (exo-tricyclo[5.2.1.0(2,6)]decane), a single-component hydrocarbon jet fuel, we carried out molecular dynamics (MD) simulations employing the ReaxFF reactive force field. We found that the primary decomposition reactions involve either (1) dissociation of ethylene from JP-10, resulting in the formation of a C(8) hydrocarbon intermediate, or (2) the production of two C(5) hydrocarbons. ReaxFF MD leads to good agreement with experiment for the product distribution as a function of temperature. On the basis of the rate of consumption of JP-10, we calculate an activation energy of 58.4 kcal/mol for the thermal decomposition of this material, which is consistent with a strain-facilitated C-C bond cleavage mechanism in JP-10. This compares well with the experimental value of 62.4 kcal/mol. In addition, we carried out ReaxFF MD studies of the reactive events responsible for oxidation of JP-10. Here we found overall agreement between the thermodynamic energies obtained from ReaxFF and quantum-mechanical calculations, illustrating the usefulness of ReaxFF for studying oxidation of hydrocarbons. The agreement of these results with available experimental observations demonstrates that ReaxFF can provide useful insights into the complicated thermal decomposition and oxidation processes of important hydrocarbon fuels.