Pyrolysis mechanism study of n-heptane as an endothermic hydrocarbon fuel: A reactive molecular dynamic simulation and density functional theory calculation study

The pyrolysis of endothermic hydrocarbon fuel with high heat sink can reduce the surface temperature of engines and aircraft fuselage. The pyrolysis mechanism of n-heptane as a model compound for endothermic hydrocarbon fuel was investigated by using ReaxFF reactive molecular dynamic simulations and density functional theory calculations. The results showed that the breakage of CC bonds of n-heptane were easier than that of CH bonds, in which the cleavage of C2C3 bond is the easiest to generate C2H5 and C5H11 radicals. Temperature has a significant effect on the pyrolysis process of n-heptane, and the increase of temperature will accelerate the pyrolysis of n-heptane and promote the formation of pyrolysis products. The pre-exponential factor and apparent activation energy of the n-heptane pyrolysis were 5.4456 × 1014 s−1 and 231.3 kJ·mol−1, respectively.