Analytical Sciences

Abstract − Analytical Sciences, 26(11), 1119 (2010).

Chlorination Mechanism of Carbon during Dioxin Formation Using Cl-K Near-edge X-ray-absorption Fine Structure
Takashi FUJIMORI, Yuta TANINO, Masaki TAKAOKA, and Shinsuke MORISAWA
Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo, Kyoto 615-8540, Japan
Many environmental organic chemicals have chloride in their structure. Thus, researching the chlorination mechanism of carbon is of interest. Dioxins are typically concentrated in fly ash collected from the post-combustion zone during the operation of municipal solid waste incinerators. In this study, we report the application of Cl-K near-edge X-ray-absorption fine structure (NEXAFS) in determining the chlorination mechanism of carbon in fly ash. The separation of a chloride–carbon (C–Cl) bond was readily recognizable as a peak in the Cl-K NEXAFS spectrum. Chlorination effects could be estimated using Cl K-edge NEXAFS with no dependence on metal species. Analysis of Cl K-edge NEXAFS spectra showed the reduction of copper(II) chloride at 300°C and oxidation of iron(III) chloride at 400°C in connection with the chlorination of carbon.