title: Recycling ash into the first stage of cyclone pre-heater of cement kiln.
abstract: Fly ash collected from the bag filter could be recycled into the first stage of the cyclone pre-heater of the cement kiln, resulting in the possible enrichment of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). In this study, soxhlet fly ash (SFA) and raw meal (RM) were selected as the basis for the PCDD/F formation experiments. The levels of 2,3,7,8-PCDD/Fs formed on the SFA and RM were observed to be 2550pg/g (157pg I-TEQ/g) and 1142pg/g (55pg I-TEQ/g), respectively. While less 2,3,7,8-PCDD/Fs was detected when SFA was mixed with RM, suggesting that recycling cement kiln ash would not largely increase the concentration of PCDD/Fs in flue gas. Furthermore, the possible influencing factors on the PCDD/F formation were also investigated. The formation of 2,3,7,8-PCDD/Fs was up to 10,871pg/g (380pg I-TEQ/g) with the adding of CuCl2, which was much higher than the results of CuO and activated carbon. Most importantly, the homologue, congener and gas/particle distribution of PCDD/Fs indicated that de novo synthesis was the dominant PCDD/F formation pathway for SFA. Lastly, principal component analysis (PCA) was also conducted to identify the relationship between the compositions of reactant and the properties of PCDD/Fs produced.
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, China.
authors.forename: Ming-Xiu
authors.initials: MX
authors.lastname: Zhan
authors.affiliation: China United Engineering Corporation, Hangzhou 310052, China.
authors.forename: Jian-Ying
authors.initials: JY
authors.lastname: Fu
authors.affiliation: Lappeenranta University of Technology, Laboratory of Environmental Engineering, P.O. Box 20, FI-53851 Lappeenranta, Finland.
authors.forename: Jouni
authors.initials: J
authors.lastname: Havukainen
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, China. Electronic address: chentong@zju.edu.cn.
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.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Li
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, China.
authors.forename: Jian-Hua
authors.initials: JH
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*; D060729:Coal Ash / Q000032:analysis*; D004147:Dioxins / Q000737:chemistry*; D017745:Incineration; D000072317:Polychlorinated Dibenzodioxins / Q000737:chemistry; D059027:Recycling / Q000379:methods*; D018505:Waste Management / Q000379:methods*
chemical_list: D000393:Air Pollutants; D060729:Coal Ash; D004147:Dioxins; D000072317:Polychlorinated Dibenzodioxins
keywords: Cement kiln; De novo synthesis; Formation; Influencing factor; PCDD/Fs; Soxhlet fly ash