The high-temperature ignition kinetics of nitroethane: A shock-tube experimental and kinetic modeling study

Nitroethane is a representative nitro-containing energetic molecule, and is considered to be a potential propellant and a fuel additive. Thus, understanding its combustion characteristics and chemistry is critical in the development of hierarchical kinetic models of nitro-containing energetic materials. Herein, we investigate the high-temperature ignition kinetics of nitroethane via experimental measurements and kinetic modeling. Ignition delay times of nitroethane are measured using a high-pressure shock tube in the temperature range 900-1150 K, at pressures of 5 and 10 bar, for equivalence ratios of 0.5, 1.0 and 2.0 in diluted air. A detailed kinetic mechanism of nitroethane is updated by incorporating new reaction rate coefficients for hydrogen abstraction reactions that are studied using quantum chemistry calculations at the G4//M06-2X/6-311++G(d, p) level of theory and transition state theory. The kinetic model simulations using the updated mechanism are in good agreement with the experimental results at all conditions. Reaction path and sensitivity analyses were conducted to understand the ignition kinetics of nitroethane, and the results reveal that abstraction reactions play a critical role in the oxidation of nitroethane in addition to the C-N bond dissociation and HONO elimination reactions.