Mechanisms of Dioxin Formation from the High-Temperature Oxidation of 2-Chlorophenol
- 24 November 2004
- journal article
- research article
- Published by American Chemical Society (ACS) in Environmental Science & Technology
- Vol. 39 (1), 122-127
- https://doi.org/10.1021/es049355z
Abstract
The homogeneous, gas-phase oxidative thermal degradation of 2-chlorophenol was studied in a 1 cm i.d., fused silica flow reactor at a concentration of 88 ppm, reaction time of 2.0 s, over a temperature range of 300 to 1000 °C. Observed products in order of yield were as follows: 4,6-dichlorodibenzofuran (4,6-DCDF) > dibenzo-p-dioxin (DD) > 1-monochlorodibenzo-p-dioxin (1-MCDD), 4-chlorodibenzofuran (4-MCDF), dibenzofuran (DF), naphthalene, chloronaphthalene, 2,4-dichlorophenol, 2,6-dichlorophenol, phenol, chlorobenzene, and benzene. In contrast to pyrolysis, 4,6-DCDF is the major product rather than DD, and 1-MCDD and naphthalene are formed at temperatures as low as 400 °C. Under oxidative conditions, •OH and Cl• are the major carriers, which favors 4,6-DCDF formation over DD or 1-MCDD through abstraction of H• through diketo- and ether- intermediates. It is proposed that below 500 °C, unimolecular tautomerization/HCl elimination and CO elimination/isomerization reactions result in the formation of 1-MCDD and naphthalene, respectively.Keywords
This publication has 30 references indexed in Scilit:
- Mechanisms of Dioxin Formation from the High-Temperature Pyrolysis of 2-ChlorophenolEnvironmental Science & Technology, 2003
- An elementary reaction-kinetic model for the gas-phase formation of 1,3,6,8- and 1,3,7,9-tetrachlorinated dibenzo-p-dioxins from 2,4,6–trichlorophenolCombustion and Flame, 2003
- Ketonization equilibria of phenol in aqueous solutionCanadian Journal of Chemistry, 1999
- Mechanisms of Formation and Destruction of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in Heterogeneous SystemsEnvironmental Science & Technology, 1995
- An Extended Flame Zone in the Combustion of CH3ClCombustion Science and Technology, 1995
- The role of gas-phase Cl2 in the formation of PCDD/PCDF during waste combustionWaste Management, 1991
- Dioxin formation in incineratorsEnvironmental Science & Technology, 1983
- 1004. Studies in the pyrolysis of organic bromides. Part VII. The maximally inhibited decomposition of cyclopentyl bromideJournal of the Chemical Society, 1957
- 749. The thermal decomposition of cyclopentyl bromideJournal of the Chemical Society, 1956
- Studies in the pyrolysis of organic bromides. Part V. The pyrolysis of cyclohexyl bromideJournal of the Chemical Society, 1955