Persistent pollutants emission abatement in waste-to-energy systems

The paper is focused on analyzing methods, which enable a substantial reduction of persistent organic pollutants (POP) emissions to meet the environmental limits. Technologies based on adsorption of harmful compounds using activated carbon, technologies DeNOx/DeDiox as well as technology of catalytic filtration using a special material REMEDIA D/F are considered and compared. The latter technology consists in using a bag-house with bags manufactured from a special material (two layers—membrane from expanded PTFE and felt with bound in catalyst) called REMEDIA, which has successfully been used for the removal of PCDD/F during recent period. An optimum design is based on the computational support concerning the bag-house. It is illustrated through an industrial application of the municipal solid waste (MSW) incinerator with capacity of 15 t/h (96.000 t/year) of waste treated which is operated as a waste-to-energy system. Based on the experience from operating this incineration plant it has been proved that even after more than 3 years operation the activity of filtration material was not decreased and efficiency of dioxins removal from flue gas ranges from 97 to 99%. These facts come from complex measurements where concentration of PCDD/F toxic congeners in both flue gas and separated flying ash was measured. We arrived at confirming expected assumptions that various congeners are not decomposed uniformly in the dioxin filter and the stage of their decomposition depends on their representation in the gas phase. It is strongly influenced by their molecular weight. Their results and experience contribute to further improving the system.