Insights into the interaction kinetics between propene and NOx at moderate temperatures with experimental and modeling methods

Yuan W, Ruwe L, Schwarz S, et al. Insights into the interaction kinetics between propene and NOx at moderate temperatures with experimental and modeling methods. Proceedings of the Combustion Institute. 2021;38(1):795-803.This work aims to provide insight into the interaction of propene with NOx from both experimental and kinetic modeling perspectives. The oxidation of propene at fuel-lean (phi= 0.23) condition and the oxidation of propene doped with NOx at fuel-lean (phi= 0.23) and fuel-rich (phi= 1.35) conditions have been investigated in a laminar flow reactor at atmospheric pressure in the temperature range of 725-1250 K. Synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) was used to achieve comprehensive, isomerresolved identification of major products and critical nitrogenous, carbonyl and hydrocarbon intermediates. To complement the experiments, a detailed kinetic model, starting from widely used core mechanisms, was developed. Rate of production analyses and sensitivity analyses were performed to interpret the experimental observations. The results show that the promoting effects of NOx on the oxidation reactivity of propene are initiated by the reactions of allyl radical with NO2 at low temperature, i.e. C3H5 -A + NO2 = C3H5O + NO. For the oxidation of the fuel-rich propene/NOx mixture, temperature-dependent mole fraction profiles of propene, O-2 and products show several distinct regions reflecting a competition between chain propagation via C3H5-A +NO2= C3H5O + NO and chain termination via C3H5-A + NO = C3H5NO. The formation and consumption chemistry of carbonyl and hydrocarbon intermediates in the presence of NOx was also analyzed and discussed. (C) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved