Redukce emisí perzistentních látek v oblasti termického využití odpadu

Persistent pollutants emission abatement in waste-to-energy systems

journal article - other

en

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.

Komunální odpady vykazují nezanedbatelný kalorický obsah a jejich výhřevnost se pohybuje obvykle v rozmezí 7 až 11 MJ/kg. Efektivní energetické využití odpadů může představovat určitý příspěvek ke zmírnění dosud trvalého nárůstu spotřeb primárních energetických zdrojů a tudíž oprávněně je na odpady z tohoto hlediska pohlíženo jako na obnovitelný zdroj energie a na spalovny odpadů jako na zařízení zabezpečující určitou formou recirkulaci energie, která byla vložena do vyřazeného výrobku při jeho produkci. Tento přístup (WTE -Waste to Energy) může být efektivní pouze v případě, že získaná suma energie, která je exportována vně procesu, je vyšší než suma energie přivedené do celého technologického procesu pro zabezpečení jeho chodu při splnění všech kriterií pro konečné exhalace a další zbytky zpracování. Různá technologická řešení spaloven se však mohou od sebe lišit jak celkovou koncepcí, tak způsobem a úrovní využití tepla uvolněného při spalování odpadů. Při splnění primárního požadavku na zneškodnění odpadu s respektování legislativních požadavků představuje hledisko hospodaření s energiemi jeden z klíčových momentů návrhu a provozu určité technologie.

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.

ukazatel stupně využití energie, ukazatel efektivnosti výroby energie, odpady, dioxiny, katalytická filtrace

PCDD/F – Dioxins – Catalytic filtration – Municipal solid waste

2008

01.05.2008

Springer Berlin

Heidelberg, Germany

1618-954X

Clean Technologies and Environmental Policy

10

2

147–153

6