Suppression of dioxins in waste incinerator emissions by recirculating SO2.
Sulphur is an effective inhibitor of the formation of Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-furans (PCDD/Fs), as was proven in laboratory and pilot plant studies. In this study, a pilot-scale system with capacity 300 N m(3) h(-1) was situated at the bypass of an actual hazardous waste incinerator (HWI) and tested to reduce the emission of PCDD/Fs. Activated carbon was used as a medium to adsorb SO2 from flue gas and release it again at the higher temperature of filtered ash detoxification to achieve SO2 circulation in the system. Most PCDD/Fs in the filtered ash are decomposed by thermal treatment. Experimental results indicate that the system is capable of stable operation with SO2 accumulation at a high level of concentration and a high reduction efficiency of PCDD/Fs. A reduction of more than 80% was already achieved without addition of other sulphur compounds. When pyrite (FeS2) was added the reduction of PCDD/Fs could reach 94%, with a residual PCDD/Fs concentration in the flue gas as low as 0.13 ng TEQ N m(-3). This SO2 recirculating and suppression technology potentially provides significant progress for dioxin emission control in waste incineration and could be useful for controlling emissions of PCDD/Fs and other chlorinated organic chemicals in China.
State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China.
Xiaoqing
X
Lin
State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China.
Mingxiu
M
Zhan
Institute of Energy and Power Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
Mi
M
Yan
Department of Public Health, School of Medicine, Zhejiang University, Hangzhou 310058, China.
Ahui
A
Dai
Environment Protection Bureau of Zhoushan, Zhoushan 316021, China.
Hailong
H
Wu
State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China. Electronic address: lixd@zju.edu.cn.
Xiaodong
X
Li
State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China.
Tong
T
Chen
State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China.
Shengyong
S
Lu
State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China.
Jianhua
J
Yan
D002681:China; D004147:Dioxins / Q000737:chemistry*; D004785:Environmental Pollutants / Q000737:chemistry*; D004787:Environmental Pollution / Q000517:prevention & control*; D017745:Incineration; D013458:Sulfur Dioxide / Q000737:chemistry*
D004147:Dioxins; D004785:Environmental Pollutants; D013458:Sulfur Dioxide
Hazardous waste incineration; Inhibition; PCDD/Fs; SO(2) circulation; Suppression; Thermal treatment of filtered ash