Experimental and kinetic modeling study of the oxidation of benzene

The oxidation of benzene under flow-reactor conditions has been studied exp erimentally and in terms of a detailed chemical kinetic model. The experime nts were performed under plug-flow conditions, at excess air ratios ranging from close to stoichiometric to very lean. The temperature range was 900-1 450 K and the residence time of the order of 150 ms. The radical pool was p erturbed by means of varying the concentration of water vapor and by adding NO. Furthermore, a few experiments were conducted on pyrolysis and oxidati on of phenol. Benzene oxidation is initiated at similar to 1000 K; the temp erature for complete oxidation depends on stoichiometry, ranging from 1100 K (very lean conditions) to 1300 K (close to stoichiometric). The water vap or level and the presence of NO have only a minor impact on the temperature regime for oxidation. The proposed chemical kinetic model was validated by comparison with the present experimental data as well as flow reactor and mixed reactor data from literature. The model provides a reasonably good de scription of the overall oxidation behavior of benzene over the range of co nditions investigated. However, before details of the oxidation behavior ca n be predicted satisfactorily. a number of kinetic issues need to be resolv ed. These include product channels and rates for the reactions of phenyl an d cyclopentadienyl with molecular oxygen as well as reaction chemistry For the oxygenated cyclic compounds Formed as intermediates in the oxidation pr ocess. (C) 2000 John Wiley & Sons, Inc.