Chlorinated aromatics from combustion: Influence of chlorine, combustion
conditions, and catalytic activity
Öberg, T., Öhrström, T.
Environmental Science & Technology 37, 3995-4000 (2003)
Abstract
Research on the formation of chlorinated aromatics in combustion processes has
mainly taken place in the laboratory. Previous attempts to correlate observation
data from commercial plants have been inconclusive. This study reports on the
outcome of an industrial experiment in a full-scale afterburner. The influence
of chlorine input, combustion temperature, and catalytic activity was
investigated in a factorial design with two blocks. Polychlorinated benzenes,
dibenzo-p-dioxins, and dibenzofurans were formed both at combustion
temperatures and below 400 °C. The results show that all three experimental
factors have statistically significant impact on the formation and release of
these toxic byproducts. The quantitative dependence between chlorine input and
the occurrence of chlorinated aromatics is of particular interest due to
previous controversy. The purpose with this study was to ensure that the
installation of a boiler for energy recovery would not cause elevated emissions
of chlorinated aromatics. The experiment demonstrated that this risk is probably
low, since the presence of catalytic material or an increase in chlorine input
is required for this to happen. A general conclusion was that industrial
experimentation employing the principles of statistical design could improve the
validity in recommendations regarding commercial plant operation.
DOI: 10.1021/es034056f
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