"De Novo"-synthesis of chlorinated biphenyls, dibenzofurans and dibenzo-p-dioxins in the fly ash catalyzed reaction of toluene with hydrochloric acid
article
Toluene is converted into benzaldehyde and halogenated aromatic oxidation products in an air atmosphere at 425 °C with fly ash from a municipal waste incineration plant as the catalyst. Several halogenated products such as chlorinated and brominated benzenes, biphenyls and traces of PCDDs/PCDFs could be detected under these conditions, resulting from the reaction of metal chlorides and hromides present on the surface of the fly ash. The addition of a “chlorine” source to the reaction gases in the form of trichloroethylene or hydrogen chloride dramatically increased the production of PCBs, PCDDs/PCDF5 and other chlorinated aromaticcompounds, giving evidence for a “de novo” synthesis of PCBs and PCDDs/PCDFs. A reaction pathway, based on the initial oxidation of toluene to benzaldehyde as the key intennediate, followed by chlorination and condensation reactions is proposed.
TNO Identifier
244670
Source
Chemosphere, 19(8-9), pp. 1141-1152.
Publisher
Pergamon Press
Collation
12 p.
Pages
1141-1152
Files
To receive the publication files, please send an e-mail request to TNO Repository.