The sensitizing effects of NO2 and NO on methane low temperature oxidation in a jet stirred reactor

An experimental, theoretical and kinetic-modeling study of the gas-phase oxidation of ammonia

“…The present JSR setup was already described in previous works. [38][39][40] Briefly, it consisted of a spherical vessel with an injection of the preheated fresh mixture through four nozzles located at the center of the reactor, which produce high turbulence leading to homogeneity in temperature and composition. The preheating and heating of the reactor were performed using Inconel Thermocoax resistances rolled around the different parts and controlled by independent K-type thermocouples.…”

“…The development of the kinetic model was performed by following a hierarchical and modular approach, as originally conceived in the CRECK kinetic framework. 48 The core H 2 /O 2 mechanism was adopted after the work of Metcalfe et al 49 The NO x module, foundation of the whole NH 3 mechanism, was taken from the work of Song et al, 38 on turn based on the works of Faravelli, Frassoldati et al 50,51 The major updates were performed on HONO/HNO 2 chemistry, after the recent work of Chen et al 52 For all the species, the…”

NOx Formation in MILD Combustion: Potential and Limitations of Existing Approaches in CFD

“…The prompt pathway has been revised in fairly recent studies that identified the formation of the NCN species as the most important initial step of the prompt route (Cui et al, 1999;Moskaleva and Lin, 2000). The kinetic parameters of the reaction of NCN formation, CH + N 2 ⇋ NCN + H, have been established within a factor of two by several experimental and modeling investigations (Vasudevan et al, 2007;Harding et al, 2008;Sutton et al, 2012;Klippenstein et al, 2018) and included in novel mechanisms (Lamoureux et al, 2016;Glarborg et al, 2018;Song et al, 2019). Since the CH species is produced by the oxidation of hydrocarbons and forms the NCN species by insertion into the triple bond of molecular nitrogen, the predictions of NO x emissions via the prompt route is also affected by the accuracy of the kinetic mechanisms of hydrocarbon oxidation (Santner et al, 2016).…”

“…The kinetics of this route is still under investigation: the uncertainty in the heat of formation of NNH may alter the NO predictions by a factor of two (Klippenstein et al, 2011), and the rate constants for the limiting reaction NNH + O ⇋ NH + NO reported in the literature (Bozzelli and Dean, 1995;Hayhurst and Hutchinson, 1998;Konnov et al, 2001;Haworth et al, 2003;Klippenstein et al, 2011) vary by more than an order of magnitude. However, recent kinetic models (Zhang et al, 2017;Glarborg et al, 2018;Song et al, 2019) have been updated with thermo-chemical and kinetic quantities estimated via ab initio transition state calculations (Klippenstein et al, 2011). The inclusion of the N 2 O and NNH routes has been crucial in obtaining accurate predictions of NO emissions for several lab-scale burners (Galletti et al, 2009;Mardani and Tabejamaat, 2012;Wang et al, 2015) and semi-industrial furnaces (Parente et al, 2011;Li et al, 2013) operating in MILD conditions.…”

A multiscale combustion model formulation for NO predictions in hydrogen enriched jet flames

“…Klippenstein et al [23] evaluated recently thermochemistry and kinetics of the reactions of the NNH pathway using ab initio transition state theory based master-equation calculations. Recent kinetic models have been updated with Klippenstein's findings [10,24,25,26]. A graphical overview of the NO formation pathways mentioned above is presented in Figure 1.…”