Pyrolysis and oxidation of phenol

Pathways of aromatic fuel oxidation have revealed the importance of phenol chemistry and motivated this study to obtain the very first stable intermediate species profiles for the atmospheric pressure oxidation of phenol near 1170 K over a range of equivalence ratios, 0.64-1.73. Under these conditions, cyclopentadiene was found to be a major reaction intermediate. Other major species observed included carbon monoxide, carbon dioxide, acetylene, benzene, 1,3-butadiene, ethene, and methane. Minor species were allene, methylacetylene, propene, ethane, methylcyclopentadiene, and naphthalene, The reaction intermediates are consistent not only with the findings of a cyclopentadiene oxidation study previously performed in this laboratory but also with reactions in the postulated mechanism of phenol oxidation. A complementary study of phenol pyrolysis indicated that carbon monoxide, cyclopentadiene, and benzene were major reaction intermediates, also consistent with an earlier study of phenol pyrolysis in this laboratory. Carbon monoxide yield was once again found to exceed that of cyclopentadiene. However, trace species not detected in the prior study were observed and now shown to account for the difference in formation of carbon monoxide and cyclopentadiene. These data and the associated mechanistic analysis should be instrumental in the further validation of benzene oxidation models and will prove essential to the understanding of the whole of aromatics fuel chemistry.