title: Formation of dioxins on NiO and NiCl2 at different oxygen concentrations.
abstract: Model fly ash (MFA) containing activated carbon (AC) as source of carbon, NaCl as source of chlorine and either NiO or NiCl2 as de novo catalyst, was heated for 1h at 350 °C in a carrier gas flow composed of N2 containing 0, 6, 10, and 21 vol.% O2, to study the formation of PCDD/Fs (dioxins) and its dependence on oxygen. The formation of PCDD/Fs with NiCl2 was stronger by about two orders of magnitude than with NiO and the difference augmented with rising oxygen concentration. The thermodynamics of the NiO-NiCl2 system were represented, X-ray absorption near edge structural (XANES) spectroscopy allowed to probe the state of oxidation of the nickel catalyst in the MFA and individual metal species were distinguished using the LCF (Linear combination fitting) technique: thus three supplemental nickel compounds (Ni2O3, Ni(OH)2, and Ni) were found in the fly ash. Principal Component Analysis (PCA) indicates that both Ni2O3 and NiCl2 probably played an important role in the formation of PCDD/Fs.
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.affiliation: College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
authors.forename: Mi
authors.initials: M
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China. Electronic address: lixd@zju.edu.cn.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Shengyong
authors.initials: S
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Tong
authors.initials: T
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Kees
authors.initials: K
authors.lastname: Olie
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Alfons
authors.initials: A
authors.lastname: Buekens
mesh_terms: D002384:Catalysis; D060729:Coal Ash / Q000737:chemistry; D004147:Dioxins / Q000737:chemistry*; D004785:Environmental Pollutants / Q000737:chemistry*; D017745:Incineration; D009532:Nickel / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*
chemical_list: D060729:Coal Ash; D004147:Dioxins; D004785:Environmental Pollutants; C022838:nickel chloride; D009532:Nickel; C028007:nickel monoxide; D010100:Oxygen
keywords: Model fly ash; Nickel chloride; Nickel oxide; XANES; de novo test