title: Suppression of dioxins after the post-combustion zone of MSWIs.
abstract: Thiourea was selected as representative of combined S- and N-inhibitors and injected after the post-combustion zone of two full-scale municipal solid waste incinerators (MSWIs) using a dedicated feeder. Firstly, the operating conditions were scrutinised by monitoring the concentrations of SO2, NH3 and HCl in the clean flue gas. The suppression experiment showed that in MSWI A thiourea could reduce the total I-TEQ value in flue gas by 73.4% from 1.41ng I-TEQ/Nm(3) to 0.37I-TEQ/Nm(3), those in fly ash by 87.1% from 14.3ng I-TEQ/g to 1.84I-TEQ/g and the total dioxins emission factor by 87.0wt.%, with a (S+N)/Cl molar ratio of 9.4. The suppression efficiencies of PCDD/Fs in flue gas and fly ash in MSWI B could be up to 69.2% and 83.0% when the (S+N)/Cl molar ratio attained 7.51. Furthermore, the congener distributions of dioxins were also analysed in the flue gas and fly ash, before and after addition of thiourea, to find cues to some suppression mechanism. In addition, the filtered fly ash was explored by the Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS) analysis of fly ash. These results suggest that poisoning the metal catalyst and blocking the chlorination are most probably responsible for suppression.
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, China.
authors.forename: Mingxiu
authors.initials: M
authors.lastname: Zhan
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, China.
authors.forename: Tong
authors.initials: T
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, China. Electronic address: linxiaoqing@zju.edu.cn.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Lin
authors.affiliation: China United Engineering Corporation, Hangzhou 310052, China.
authors.forename: Jianying
authors.initials: J
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, China.
authors.forename: Alfons
authors.initials: A
authors.lastname: Buekens
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000517:prevention & control*; D004147:Dioxins / Q000032:analysis*; D004784:Environmental Monitoring; D017745:Incineration / Q000379:methods*; D062611:Solid Waste / Q000032:analysis
chemical_list: D000393:Air Pollutants; D004147:Dioxins; D062611:Solid Waste
keywords: MSWI; PCDD/Fs; Post-combustion; S-N inhibitors; Suppression; Thiourea