Presentation
Rate coefficients for H+NO2→OH+NO from high pressure flow reactor experiments
9th U. S. National Combustion Meeting
(2015)
Abstract
Rate coefficients for the reaction H+NO2 → OH+NO (R1) were determined over the
nominal temperature and pressure ranges of 737-882 K and 10-20 atm, respectively, from spatially
resolved measurements in two different flow reactor facilities: one laminar and one turbulent. The
title reaction is important in a variety of situations including NO↔NO2 interconversion in the
power extraction stage of gas turbines, exhaust gas recirculation (EGR)-affected ignition in
reciprocating engines, and for H atom titration in elementary gas phase kinetics experiments. This
work determines absolute values of k1 with reference to the relatively well known rate coefficients
for H+O2+M → HO2+M (R2.M) for M = Ar and N2 and a quasi-steady state NOx plateau (QSSP)
method that measures the ratio of k1 to k2.M. At QSSP conditions established during NOxperturbed
H2 oxidation, this rate coefficient ratio is algebraically determined (i.e., without complex
kinetic model fitting) from measurements of the temperature, pressure, and NO2 and O2 mole
fractions taken from the quasi-steady plateau reaction. Values of k1 determined here are in very
good agreement with a present fit (k1(T) = 2.5 × 1013 T0.218 [cm3/mol/s]) to the theoretical variable
reaction coordinate – flexible transition state theory (VRC-FTST) k1 expression of Su et al.
(2002), as well as extrapolation of the experiment-advised expression of Ko & Fontijn (1991) to
higher temperatures. Present uncertainties in k1 determinations also overlap the uncertainty band
for the experiment-based, temperature-invariant k1 value from Su et al. for 195 ≤ T (K) ≤ 2000.
Finally, it is to be noted that while measurements from the laminar reactor are new to the
literature, the k1 determinations from the turbulent flow reactor are based on reinterpretation of
experiments performed by Mueller et al. (1998) intended to determine k2.M relative to k1.
Keywords
- NOx chemistry,
- Flow reactor,
- Rate Constant,
- Hydrogen Reactions
Disciplines
Publication Date
May, 2015
Location
Cincinnati, Ohio
Citation Information
Francis M. Haas and Frederick L. Dryer. "Rate coefficients for H+NO2→OH+NO from high pressure flow reactor experiments" 9th U. S. National Combustion Meeting (2015) Available at: http://works.bepress.com/francis-haas/4/
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