Effect of injection of di- and tricyclic aromatic compounds on post-combustion formation of polychlorinated dibenzo-p-dioxins and dibenzofurans

Jansson, Stina; Fick, Jerker; Tysklind, Mats

doi:10.1016/j.scitotenv.2011.05.023

Research article2011Peer reviewed

Effect of injection of di- and tricyclic aromatic compounds on post-combustion formation of polychlorinated dibenzo-p-dioxins and dibenzofurans

Jansson, Stina; Fick, Jerker; Tysklind, Mats

Abstract

The formation of mono- to octachlorinated dibenzo-p-dioxins (PC(1-8)DD) and dibenzofurans (PC(1-8)DF) was studied using a model waste in a laboratory-scale combustion reactor with simultaneous collection of flue gas at three different temperatures (450 degrees C. 300 degrees C. and 200 degrees C) in the post-combustion zone. To investigate the influence of chlorination reactions and the effects of carbon backbone-containing compounds present in the flue gases, five aromatic compounds were injected into the flue gas, namely dibenzofuran (OF), biphenyl (BP), naphthalene, phenanthrene and fluorene. The injection of OF induced a reduction in the concentration of PC(3-5)DD, but did not significantly influence the concentration of PCDF. A reduction in the concentration of PC(3-5)DD was also observed during the injection of fluorene, which is structurally very similar to OF. The injection of biphenyl, naphthalene and phenanthrene had less pronounced effects on the formation of PCDD and PCDF. A possible explanation of the observed changes during injection of OF and fluorene, based on homologue profiles and affected congeners, involves formation of radical species from fluorene and/or dibenzofuran. The fluorene radical is stabilized by the delocalization of electrons across the aromatic ring structure and has the propensity to react with highly abundant hydrogen chloride, whereas the molecular species would require reaction with Cl(2) or chlorine radicals. (C) 2011 Elsevier B.V. All rights reserved.

Keywords

PCDD/F; Waste combustion; Fluorene; Biphenyl; Naphthalene; Phenanthrene

Published in

Science of the Total Environment
2011, volume: 409, number: 18, pages: 3386-3393
Publisher: ELSEVIER SCIENCE BV

SLU Authors

Jansson, Stina
- Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences

UKÄ Subject classification

Environmental Sciences and Nature Conservation

Publication identifier

DOI: https://doi.org/10.1016/j.scitotenv.2011.05.023

Permanent link to this page (URI)

https://res.slu.se/id/publ/46504