S. Sidhu, P. Edwards
2002
Citations
1
Influential Citations
26
Citations
Journal
International Journal of Chemical Kinetics
Abstract
In this work, the role of phenoxy radicals in polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) formation was investigated by studying the slow oxidation of 2-chlorophenol (2-CP) and 2-chloroanisole (2-CA) at a gas-phase concentration of 4 ppm (∼2.1 × 104 μg/m3) over a temperature range of 400–800°C. Residence times were maintained at 2.0 ± 0.10 s. PCDD/F reaction products were dibenzofuran, dibenzo-p-dioxin, 4-chlorodibenzofuran, 1-chlorodibenzo-p-dioxin, 4,6-dichlorodibenzofuran, and 1,6-dichlorodibenzo-p-dioxin (1,6-DCDD). Major products observed in these experiments were 2,6-dichlorophenol, 3-phenyl-2-propenal, 1-indanone, 1,3-isobenzofurandione, and 3-phenyl-2-propenoyl chloride. The 2-CP and 2-CA experiments, along with the variable concentration 2-CA experiments, showed that the concentration of radicals present in the oxidation system has a significant effect on the PCDD/F product distribution and ultimately the PCDD/PCDF ratio. Also, the observation of dichlorinated phenoxy phenol and dichlorinated dihydroxybiphenyl, the proposed intermediate species in the radical–radical mechanism, suggests that radical–radical mechanism dominates gas-phase PCDD/F formation. This information will be helpful in constructing a detailed kinetic mechanism of PCDD/F formation/destruction in combustor postcombustion zone. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 531–541, 2002