Wood waste and industrial wood residues often contain various preservatives. The waste management for these residuals can be recycling, deposition or combustion. Among the three possibilities, combustion seems to be the most efficient way of usage. To obtain more information about the emission properties of treated wood, different materials were incinerated in different furnaces after mixing with non-treated wood in a ratio of 1:4. For sake of comparison, combustion was also performed using non-impregnated wood only. The combustion process of residues containing organic or inorganic preservatives is influenced by the elementary composition of the preservative and the thermal and oxidative reaction paths in the flame. Organic preservatives mostly can be thermally destructed by usual combustion conditions. Elevated conditions are necessary for preservatives based on creosotes (tar oil). Among inorganic preservatives, volatile ingredients like fluorine have a considerable environmental impact. Other elements like copper, chromium and boron remain in ashes and cinders reducing the emission problem towards an effective dust removal. It was also found that the concentrations of the gaseous emission components CO, NOx and CmHn are not increased in comparison to the values being found for non-treated wood. However, the concentrations of polychlorinated dibenzo-dioxins and -furans in the exhaust gas could only be kept low under optimized combustion conditions.

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