Experimental measurements and kinetic modeling of CH₄/O₂ and CH₄/C₂H₆/O₂ conversion at high pressure

Abstract

A detailed chemical kinetic model for homogeneous combustion of the light hydrocarbon fuels CH4 and C2H6 in the intermediate temperature range roughly 500–1100 K, and pressures up to 100 bar has been developed and validated experimentally. Rate constants have been obtained from critical evaluation of data for individual elementary reactions reported in the literature with particular emphasis on the conditions relevant to the present work. The experiments, involving CH4/O2 and CH4/C2H6/O2 mixtures diluted in N2, have been carried out in a high‐pressure flow reactor at 600–900 K, 50–100 bar, and reaction stoichiometries ranging from very lean to fuel‐rich conditions. Model predictions are generally satisfactory. The governing reaction mechanisms are outlined based on calculations with the kinetic model. Finally, the mechanism was extended with a number of reactions important at high temperature and tested against data from shock tubes, laminar flames, and flow reactors. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 778–807, 2008

High pressure oxidation of C2H4/NO mixtures

“…Surface reactions were not included in the model. Our previous work on CH 4 oxidation [12] indicated loss of peroxides, but the similar work on C 2 H 4 [1] showed no evidence of surface reactions. Either way, surface loss of peroxides would be minimized under the present conditions since they are rapidly removed by reaction with NO.…”

“…The mechanism used for the modeling study, as well as the corresponding thermodynamic properties, was drawn from previous high-pressure work on conversion of CO/H 2 /O 2 /NO x [11], CH 4 /C 2 H 6 /O 2 [12], and CH 4 /O 2 /NO x [13]. Recently, it was updated to describe C 2 H 4 oxidation at high pressure, with particular emphasis on a number of oxygenated C 2 -species important under low-temperature conditions [1].…”

Ab initio and kinetic modeling studies of formic acid oxidation

“…In the present study, the starting mechanism and corresponding thermodynamic properties were drawn from recent work by the authors on oxidation of H 2 , CO and C 1 /C 2 hydrocarbons [27][28][29][30]. Both the thermochemistry and the HOCHO oxidation subset of the mechanism were carefully updated.…”

Experimental and kinetic modeling study of C2H4 oxidation at high pressure

“…The starting mechanism and corresponding thermodynamic properties were drawn from previous high-pressure work on oxidation of CO/H 2 , CH 4 , and CH 4 /C 2 H 6 [18,19]. The only change in the C 1 subset was the omission of the reaction HOCO+OH CO+H 2 O 2 , pending further investigation.…”

“…The oxidation pathways for C 2 H 4 under these conditions are different from those prevailing at higher temperatures and lower pressures and the results of the current work help to extend the validation range for chemical kinetic modeling of C 2 H 4 oxidation. This paper is part of a series investigating the high-pressure, medium temperature oxidation of simple fuels: previously work has been reported for CO/H 2 , CH 4 , and CH 4 /C 2 H 6 mixtures [18,19]. The present kinetic model draws on this work, as well as recent results in tropospheric chemistry.…”