Janusz Bujak

The technology of waste-management thermal processing may pose a threat to the natural environment through the emission of harmful substances, such as CO, NOx, SO₂, HCl, HF, total organic carbon (TOC) and dust, as well as dioxins and furans. Due to the advantages of thermal waste treatment, including the small volume of solid residue produced and possible thermal energy recovery, thermal waste treatment is widely applied. Continuous research is necessary to develop methods for reducing the risk of harmful substances being produced and methods for the effective removal of pollutants resulting from flue gases. This paper presents an analysis of the results and conditions of the experimental redesign of a thermal industrial waste (polypropylene) treatment plant. The purpose of the redesign was to improve the quality of gasification and afterburning processes taking place in the combustion and afterburner chambers (through the installation of an additional section), thus resulting in a reduction in the concentrations of CO and total organic carbon (TOC) in flue gases. The research concerned a facility implementing the combustion process on an industrial scale. The experiment led to a reduction in the average concentrations of carbon monoxide from 16.58 mg/m³ to 3.23 mg/m³ and of volatile organic compounds from 2.20 mg/m³ to 0.99 mg/m³. At the same time, no deterioration was observed in any of the remaining technological parameters of the plant, such as waste combustion performance and the energy efficiency of the thermal energy recovery system.

Nitrogen oxides, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans are pollutants formed during thermal processes, in particular during the combustion of various fuels, including waste. They are classified as dangerous and highly toxic environmental pollutants whose emissions are strictly regulated. Many methods for reducing their emissions are known, but all involve additional production costs. For this reason, effective and cheap methods for removing these pollutants from exhaust gases are still sought. Selective non-catalytic reduction of nitrogen oxides is one of the more effective and cheaper methods for reducing these emissions. However, an alternative to expensive methods for dioxin and furan removal (catalysis, adsorption, etc.) may include using dioxin synthesis inhibitors. The authors propose a method for the simultaneous removal of both pollutants from flue gases using selective non-catalytic reduction technologies with dioxin synthesis inhibitors used as reducing agents.