Mechanism of Dioxins/Furans Formation at High Temperature in Combustion Processes

Abstract

To understand the mechanism of toxic dioxins/furans (Dioxins) formation in incineration processes, the combustion experiments were carried out with an electric furnace in laboratory scale at 1 073 K using mainly the powder of regent grade polyvinyl chloride (PVC powder) as a combustion material under a complete and an incomplete combustion conditions. In addition, the thermodynamic evaluations have been done on the formation and decomposition of Dioxins.
Dioxins are formed even at the combustion temperature of 1 073 K under the conditions in which the fly carbonaceous matters exist. It is supposed that Dioxins are mainly formed on the surface of the fly carbonaceous matters where high CO/CO₂ ratio is established. Dioxins' concentration is correlated with the number of the fly carbonaceous matters in an exhaust gas. The formation/suppression of Dioxins is dependent upon the amount of the fly carbonaceous matters remained in the exhaust gas from the combustion furnaces.