Exploring pyrolysis and oxidation chemistry of o-xylene at various pressures with special concerns on PAH formation

This work reports an experimental and kinetic modelling investigation on flow reactor pyrolysis jet-stirred oxidation of o-xylene. The experiments were conducted over 1050–1600 K at 0.04 1.0 atm. Key products related to fuel decomposition such as o-xylyl radical, o-xylylene, benzocyclobutene styrene, well polycyclic aromatic hydrocarbons (PAHs), detected by using synchrotron vacuum ultraviolet photoionization mass spectrometry. performed 10 atm, 800–1200 K, a residence time 0.5 s equivalence ratios 0.5, 2.0. Speciation gas chromatography Fourier transform infrared A model o-xylene was developed from our previous models fuels validated against both present data in literature. Styrene is observed the dominant product it mainly produced isomerization o-xylylene directly or via intermediate species. C9 PAHs (indenyl, indene indane), phenanthrene its methyl derivatives abundantly bicyclic tricyclic PAHs. main formation pathways are found be different low atmospheric pressures, depending major precursors produced. Particularly, self-combination reactions addition reaction with benzyl subsequent stepwise H-loss/cyclization sources methylphenanthrene dimethylphenanthrene. In JSR o-xylene, toluene benzene products, while o-methylbenzaldehyde among most oxygenated aromatics. analysis reveals that radical also consumption product. Its proceeds through HO2 finally produces o-methylbenzaldehyde. Further contribute other aromatics cresol benzofuran. Indene naphthalene which sequence o-methylethylbenzene dibenzofuran, respectively.