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

Abstract

In order to further understand the high-temperature reaction process and pyrolysis mechanism of hydrocarbon fuels, the high-temperature pyrolysis behavior of n-tetracosane (C24H50) was investigated in this paper via the reaction force field (ReaxFF) method-based molecular dynamics approach. There are two main types of initial reaction channels for n-heptane pyrolysis, C-C and C-H bond fission. At low temperatures, there is little difference in the percentage of the two reaction channels. With the temperature increase, C-C bond fission dominates, and a small amount of n-tetracosane is decomposed by reaction with intermediates. It is found that H radicals and CH3 radicals are widely present throughout the pyrolysis process, but the amount is little at the end of the pyrolysis. In addition, the distribution of the main products H2, CH4, and C2H4, and related reactions are investigated. The pyrolysis mechanism was constructed based on the generation of major products. The activation energy of C24H50 pyrolysis is 277.19 kJ/mol, obtained by kinetic analysis in the temperature range of 2400-3600 K.