OXIDATION OF m-XYLENE IN A JSR: EXPERIMENTAL STUDY AND DETAILED CHEMICAL KINETIC MODELING

Abstract

New experimental results were obtained for the oxidation of meta-xylene studied in a jet-stirred reactor at atmospheric pressure in dilute conditions over the temperature range 900–1400 K, and variable equivalence ratio (0.5 ≤ ϕ ≤ 1.5). They consisted of concentration profiles of the reactants, stable intermediates and final products, measured by sonic probe sampling followed by on-line GC-MS analyses and off-line GC-TCD-FID and GC-MS analyses. The oxidation of meta-xylene in these conditions was modeled using a detailed chemical kinetic reaction mechanism (189 species and 1359 reactions, most of them reversible) deriving from a previous scheme proposed for the ignition, oxidation, and combustion of simple aromatics (benzene, toluene, styrene, n-propyl-benzene, and para-xylene). Sensitivity analyses and reaction path analyses, based on rates of reaction, were used to interpret the results. This study showed the reactivity of m-xylene is quite similar to that of p-xylene under the present conditions: m-xylene reacts slightly slower than p-xylene.

Keywords:

• Aromatic
• JSR
• Kinetic modeling
• meta-xylene
• Pseudocumene
• Reaction mechanism

S. G. thanks the French MENRT for a Doctoral grant. The authors are grateful to Dr. F. Lecomte for his help with the experiments and to Dr. M. Cathonnet for his interest in this research.

Notes

Nomenclature: 5-methylcyclopenta-1,3-diene, MeCPD; 5-methyl-1,3-cyclopentadienyl, MeCDPY; 4-methyl-1-hydroxybenzene, m-MePhOH; 3-methyl-1-hydroxybenzene radical, m-OC₇H₇; 3-methyl-phenyl radical, m-C₆H₄CH₃; 3-formyl-phenyl radical, Y1P3CHO; 3-formyl-1-hydroxybenzene radical, OY1P3CHO; 1,3-dimethyl-benzene, m-xylene; 3-methyl-benzyl radical, m-xylyl; 1-formyl-3-methyl-benzene, m-MePhHCO; 1-carbonyl-3-methyl-benzene radical, m-MePhCO; 3-methyl-1-hydroxy methyl-benzene, m-MePhCH₂OH; 3-methyl-1-hydroxydedydro-1-methyl-benzene radical, m-MePhCHOH; 3-methyl-1-hydroxymethyl-benzene radical, m-MePhCH₂O; 1,3-diformyl-benzene, m-CHOPhCHO; 1-carbonyl-3-formylbenzene radical, m-CHOPhCO; 3-formyl-benzyl radical, m-CHOPhCH₂; 3-ethyl-phenyl radical, Y1P3Et; 3-ethyl-1-hydroxybenzene radical, OY1P3Et; 3-ethyl-1-methyl-benzene, m-MePhC₂H₅; 3-methyl-1-ethylene-benzene radical, m-AMePhC₂H₄; 3-methyl-1-ethylidene-benzene radical, m-BMePhC₂H₄; 3-methyl-1-vinylbenzene, m-MeStyrene; 3-methyl-1-ethen-1-yl benzene radical, m-AMeStyryl; 3-methyl-1-ethen-2-yl benzene radical, m-BMeStyryl; 1-formyl-3-ethyl-benzene radical, m-EtPhHCO; 1-carbonyl-3-ethyl-benzene radical, m-EtPhCO; 3-ethyl-benzyl radical, MY1P3Et; 3,3′-dimethyl-biphenyl, m-MePPMe; 3,3′-dimethyl-bibenzyl, m-DiPhCH₂.

Note: (a) Based on previous work on p-xylene (Gaïl and Dagaut, 2005); (b) Emdee (1991); (c) Emdee et al., 1992; (d) Hippler et al., 1994.

Units: ΔH °_f(298) in kcal/mol; ΔS°_f(298) and C_p (T) in cal/mol/K.