Shock-Tube Experiments and Kinetic Modeling of CH3NHCH3 Ignition at Elevated Pressures

Ignition delay times of CH3NHCH3/O-2/Ar mixtures are measured with a shock tube in the temperature range of 1040-1604 K. Different pressures (4, 8, and 18 atm) and equivalence ratios (0.5, 1, and 2) are investigated. A recently developed CH3NHCH3 kinetic model is examined, and then modified by adding the hydrogen abstractions from CH3NHCH3 by HO2 and NO2. The rate constants of the hydrogen abstraction by HO2 are estimated by analogy to the CH3OH + HO2 system, and those of the hydrogen abstraction by NO2 by analogy to the CH3NH2 + HO2 system. The modified model is well validated against the present measurements. Based on this model, sensitivity analysis and reaction pathway analysis are performed to provide insight into the chemical kinetics of CH3NHCH3 ignition. CH3NHCH3 is mainly consumed by hydrogen abstractions at low temperatures, and its unimolecular decomposition becomes important at higher temperatures. (C) 2017 Wiley Periodicals, Inc.