Experimental and kinetic modeling study of the oxidation of benzene

Article abstract of DOI:10.1002/1097-4601(2000)32:8<498::AID-KIN8>3.0.CO;2-H

The oxidation of benzene under flow-reactor conditions has been studied experimentally and in terms of a detailed chemical kinetic model. The experiments were performed under plug-flow conditions, at excess air ratios ranging from close to stoichiometric to very lean. The temperature range was 900-1450 K and the residence time of the order of 150 ms. The radical pool was perturbed by means of varying the concentration of water vapor and by adding NO. Furthermore, a few experiments were conducted on pyrolysis and oxidation of phenol. Benzene oxidation is initiated at approximately 1000 K; the temperature for complete oxidation depends on stoichiometry, ranging from 1100 K (very lean conditions) to 1300 K (close to stoichiometric). The water vapor 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 description of the overall oxidation behavior of benzene over the range of conditions investigated. However, before details of the oxidation behavior can be predicted satisfactorily, a number of kinetic issues need to be resolved. These include product channels and rates for the reactions of phenyl and cyclopentadienyl with molecular oxygen as well as reaction chemistry for the oxygenated cyclic compounds formed as intermediates in the oxidation process.