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

Ignition delay times of CH₃NHCH₃/O₂/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.