Experimental and Kinetic Modeling Study of Nitroethane Pyrolysis at a Low Pressure: Competition Reactions in the Primary Decomposition

The pyrolysis of nitroethane has been investigated over the temperature range of 682-1423 K in a plug flow reactor at a low pressure. The major species in the pyrolysis process have been identified and quantified using tunable synchrotron vacuum ultraviolet photoionization mass spectrometry and molecular beam sampling techniques. The rate constants for the primary pyrolysis of nitroethane as well as those for the decomposition of the secondary product CH3CHNO2 have been obtained via ab initio calculations. These results have been adopted in a detailed chemical kinetic model, which contains 95 species and 737 reactions. The model was validated against the experimental results with satisfactory agreement for most of the identified and quantified species. Further analysis on the results indicates that both the concerted molecular elimination and C-N bond rupture are significant in the primary pyrolysis of nitroethane, with the latter channel being more important at high temperatures. The adoption of new decomposition pathways of CH3CHNO2 has resulted in reasonable predictions for relevant intermediates.