High-Temperature Pyrolysis of N-Tetracosane Based on ReaxFF Molecular Dynamics Simulation

In order to further understand the high-temperature reactionprocessand pyrolysis mechanism of hydrocarbon fuels, the high-temperaturepyrolysis behavior of n-tetracosane (C24H50) was investigated in this paper via the reaction forcefield (ReaxFF) method-based molecular dynamics approach. There aretwo main types of initial reaction channels for n-heptane pyrolysis, C-C and C-H bond fission. At lowtemperatures, there is little difference in the percentage of thetwo reaction channels. With the temperature increase, C-C bondfission dominates, and a small amount of n-tetracosaneis decomposed by reaction with intermediates. It is found that H radicalsand CH3 radicals are widely present throughout the pyrolysisprocess, but the amount is little at the end of the pyrolysis. Inaddition, the distribution of the main products H-2, CH4, and C2H4, and related reactions areinvestigated. The pyrolysis mechanism was constructed based on thegeneration of major products. The activation energy of C24H50 pyrolysis is 277.19 kJ/mol, obtained by kinetic analysisin the temperature range of 2400-3600 K.