Effective Removal Pcdd/Fs and Other Pops from Municipal Solid Waste Incinerator Fly Ash via Catalytic Pyrolysis(3/3)

The amount of bottom ash (BA) and fly ash (FA) released from all municipal solid waste incinerators (MSWIs) in Taiwan is between 1,200,000 to 1,300,000 tons/year. FA is classified as hazardous waste because it contains high concentrations of chloride, heavy metals and organic pollutants (PCDD/Fs, dl-PCBs, PCN and PAHs). To attain the target of “zero waste policy” enacted by Taiwan EPA, recycle of FA from MWIs should be conducted. Previous studies indicate that 95% of PCDD/Fs in fly ash can be removed at 350oC under oxygen-deficit condition. However, formation of other organic pollutants is observed in the exhaust gas of the pyrolysis system. In this study, FA will be pre-washed to reduce chloride content before being treated with catalytic pyrolysis and PCDD/Fs, dl-PCBs, PCN and PAHs concentrations in fly ash and exhaust gas will be determined. Moreover, different palladium (Pd)-based catalysts will be added to the pyrolysis process in in-situ and ex-situ system at a temperature lower than 350oC to enhance the PCDD/Fs destruction efficiency and reduce the formation of organic pollutants formation in the exhaust gas. The mechanisms for removing PCDD/Fs in the catalytic pyrolysis treatment system are complicated. Therefore, this study is expected to propose appropriate