Experimental and modeling investigation of nitrogen-containing product formation during N,N-dimethylformamide (DMF) oxidation in a jet-stirred reactor (JSR)

The oxidation of N, N-dimethylformamide (DMF) was investigated both experimentally and numerically. Experiments were carried out in a fused silica jet-stirred reactor (JSR) under atmospheric pressure covering a temperature range of T = 500–900 °C with different equivalence ratio (φ=0.5, 0.7, 0.9 and 1.2). A detailed analysis of the main nitrogen-containing products and intermediates was performed, and the results were interpreted with an improved kinetic model, describing the oxidation mechanism of DMF and the nitrogen conversion path. The measurements suggest that the primary nitrogen-containing products of DMF oxidation are HCN, NO, and N₂O, with HCN identified as a key intermediate. Kinetic analysis shows that higher temperatures promote H₂CN decomposition to stimulates the production of HCN, while increased O₂ levels enhance OH radical production, which facilitates the conversion of HCN to NO and N₂O. At 750 °C, flux analysis elucidated the main conversion pathways for NO and N₂O, providing valuable information for optimizing combustion and emissions control processes. The main conversion pathway of NO is Fuel-N→CH₃N(CH₂)CHO→CH₃NCH₂→CH₂NCH₂→H₂CN→HCN→NCO→HNCO→NH₂→H₂NO→HNO→NO, while the main conversion pathway of N₂O is Fuel-N→CH₃N(CH₂)CHO→CH₃NCH₂→CH₂NCH₂→H₂CN→HCN→NCO→N₂O. The findings offer important implications for reducing nitrogen-based pollutants in industrial applications, contributing to a more sustainable approach to DMF oxidation.