Gas phase oxidation of nitromethane

Abstract

The reaction of nitromethane with oxygen has been studied in the temperature range (700 to 740°K) in a static vessel using both g.p.c. techniques associated with an original sampling procedure [11] and spectroscopic measurements. The explosion limit, markedly lowered when compared with the case of nitromethane alone, is determined as a function of temperature or of O 2 concentration. Accurate atomic balances permit the use of the experimental results to derive a simplified mechanism from a “possible mechanism” comprising 121 steps. The simulation of the “simplified mechanism” gives results that are seen to match the data well not only for the oxidation of CH 3NO 2 but also for its pyrolysis and nitration provided that a new way of formation of HCN is introduced. The simulations allow an estimation of the order of magnitude of several rate constants, the values of which are not precisely known. For example, the rate constant of the reaction CH 3NO 2 + OH → CH 2NO 2 + H 2O may be about 2.4 sx 10 11 to 3.0 × 10 11 cm 3 mol −1 s −1 in the temperature range 700 to 740°K.