Detailed Kinetic Modeling of the Pyrolysis of 1,5,9-Decatriene. Part I: Experimental and Automated Chemical Kinetics Mechanism Generation

Author(s):

Joshua L. Lansford, Chiung-Chu Chen, Rodger E. Cornell, Christopher P. Stone, Michael J. McQuaid, Jeffrey D. Veals, Nimal Naser, Gina M. Fioroni, and Robert L. McCormick

Abstract:

As part of an ongoing effort leveraging machine learning techniques to accelerate the development of detailed chemical kinetics mechanisms for modeling the decomposition and combustion of energetic materials, this study investigates the application of Massachusetts Institute of Technology’s Reaction Mechanism Generator (RMG) for autonomously producing chemical kinetics mechanisms for 1,5,9-decatriene (DTE)—a commercially available hydrocarbon with a well-defined molecular structure similar to hydroxyl-terminated polybutadiene. In this work, predictions using mechanisms generated with RMG for the pyrolysis of DTE were compared with measurements from flow reactor experiments conducted for this work as a case study of RMG’s capabilities. The experiments were conducted by the National Laboratory of the Rockies’ Fuels and Combustion Science Group using their laminar flow reactor that was set to a constant pressure of 5 bar, a constant residence time of 0.5 s, and explored temperatures ranging from 800 to 1200 K in 50 K increments. Predicted and measured mole fraction profiles show reasonable agreement for the decay of DTE, the formation of two primary products (1,5-hexadiene and 1,3-butadiene), and the formation of C₂ species, including ethane (C₂H₆) and ethene (C₂H₄). However, of the 26 product species observed experimentally, 7 were not predicted by the model. An analysis of the pyrolysis reaction pathways revealed that additional reactions must be incorporated into the mechanism to improve agreement with all experimental measurements. These results will be presented in greater detail in Part II of this three-part technical report.