Theoretical and modeling studies on the kinetics of diethylamine dehydrogenation and subsequent isomerization and decomposition reactions

Small-molecule nitrogen-containing contaminants can be produced by the pyrolysis of diethylamine (DEA) alone or in conjunction with other molecules. To investigate the theoretical chemistry of the combustion of DEA, the CBS method determines the potential energy surface and the rate constants are calculated based on a combination of RRKM and TST theories. The H-abstraction reactions by H radicals are more kinetically advantageous. Site α has the most difficult H-abstraction procedure, but site γ has the competitive capacity to form subsequent products. The H-abstraction by NO₂ radical produces trans-HONO, cis-HONO, and HNO₂. For the reaction channels of DEA radicals, decomposition reactions have more kinetic advantages than isomerization. Kinetic parameters were obtained and the model was modified based on the fitted rate constants. The modified model has better predictive ability at low temperatures. This work provides extensive data to improve the modeling of DEA combustion at low and medium temperatures.