An experimental and modeling investigation of the oxidation chemistry of 1,2,4-trimethylbenzene in jet-stirred reactor and flow reactor

Species measurements of the gaseous products during oxidation were conducted using a jet-stirred reactor (JSR) and flow reactors to get insight into the combustion chemistry of 1,2,4-trimethylbenzene. The JSR oxidation experiments were performed at pressures of 1 and 10 atm, temperatures of 900–1400 K, equivalence ratios of 0.25–1.5, and residence times of 0.1 and 0.5 s. Key products, such as CO, CO 2 , and fuel, as well as small hydrocarbons and monocyclic aromatics, were quantified using gas chromatography. Fuel-rich oxidation was studied using atmospheric-pressure flow reactors at gas temperatures from 1000 to 1350 K, equivalence ratio of 9.0, and residence time of 1.0 s or 1.2 s. The mole fractions of small hydrocarbons from C 1 to C 7 were quantified by gas chromatograph with a flame ionization detector, while those of polycyclic aromatic hydrocarbons (PAHs) were measured using gas chromatograph mass spectroscopy combined with electron ionization. A detailed kinetic model for 1,2,4-trimethylbenzene oxidation was developed by refining our recently reported mechanism in terms of fuel-specific reactions and validated against not only the present data but also the several literature data. Kinetic analysis in the JSR oxidation demonstrated that dimethyl phenyl was an important intermediate species, while benzene and toluene were important stable aromatic species. Conversely, it was also revealed that several aromatics, such as benzene, toluene, indene, and methyl naphthalene played a significant role in PAH growth reactions in the fuel-rich oxidation in a flow reactor. Also, several small species, such as acetylene, propargyl, and cyclopentadienyl, were identified as important building blocks in mass growth reactions.