Detailed kinetic modeling of nitroglycerin low-temperature decomposition

Abstract

Nitroglycerin (NG) is mostly used as an ingredient in double-base propellant formulations. In this study, a first automatically generated detailed kinetic model of NG decomposition has been developed. The construction of this model was made possible by performing computations with the open source software package Reaction Mechanism Generator (RMG). To enable a faster convergence, significant intermediate species of NG decomposition and optimized operating conditions were indicated in the RMG input parameters. Thermochemical data related to the significant NG decomposition species were derived from ab initio calculations at the B3LYP 6-31G(d, p) level of theory. To validate the RMG-built mechanism, simulations were performed with CHEMKIN-Pro. Computed species profiles from simulations were compared with flash pyrolysis measurements from the literature. Sensitivity analysis were performed and the most important elementary reactions were identified. Some rate constants were slightly adjusted to improve the predictivity of the model. The model is able to predict the species concentration profile of the main pyrolysis products. Although experimental data are scares, this automated kinetic generation approach, applied to energetic materials, seems to be highly promising.