Formation and removal of PCDD/Fs in a municipal waste incinerator during different operating periods.
The PCDD/F concentrations and removal efficiencies achieved with air pollution control devices (APCDs) during different operating periods (start-up, normal operation, and shut-down) at an existing municipal waste incinerator (MWI) in Taiwan are evaluated via stack sampling and analysis. The MWI investigated is equipped with electrostatic precipitators (EP), wet scrubbers (WS), and selective catalytic reduction system (SCR) as APCDs. The sampling results indicate that the PCDD/F concentrations at the EP inlet during start-up period were 15 times higher than that measured during normal operation period. The PCDD/F concentration observed at shut-down period was close to that measured at normal operation period. The CO concentration was between 400 and 1000 ppm during start-up period, which was about 50 times higher compared with the normal operation. Hence, combustion condition significantly affected the PCDD/F formation concentration during the waste incineration process. In addition, the distributions of the PCDD/F congeners were similar at different operating periods. During the normal operation and shut-down periods, the EP decreases the PCDD/F concentration (based on TEQ) by 18.4-48.6%, while the removal efficiency of PCDD/Fs achieved with SCR system reaches 99.3-99.6%. Nevertheless, the PCDD/F removal efficiency achieved with SCR was only 42% during the 19-h start-up period due to the low SCR operating temperature (195 degrees C).
Wang
Hou Chuan
HC
Environmental Health and Air Pollution Division, Center for Environmental, Safety and Health Technology, Industrial Technology Research Institute, Hsin-Chu 310, Taiwan, ROC.
Hwang
Jyh Feng
JF
Chi
Kai Hsien
KH
Chang
Moo Been
MB
D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D001572:Benzofurans / Q000737:chemistry / Q000302:isolation & purification; D002248:Carbon Monoxide / Q000032:analysis / Q000737:chemistry; D002384:Catalysis; D002947:Cities; D004784:Environmental Monitoring; D017745:Incineration; D010084:Oxidation-Reduction; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification; D013624:Taiwan; D013997:Time Factors; D018505:Waste Management / Q000295:instrumentation / Q000379:methods*; D014866:Waste Products
D000393:Air Pollutants; D001572:Benzofurans; D000072317:Polychlorinated Dibenzodioxins; D014866:Waste Products; D002248:Carbon Monoxide