Investigation of the Pathways to PCDDs/FS from An Ethylene Diffusion Flame: Formation from Soot and Aromatics
The formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs) has been shown to occur from the combustion products of fuels as complex as municipal solid waste and as relatively simple as a methane flame. PCDD/F emissions from flame carbon in the presence of gas-phase chlorine and municipal solid waste incinerator fly ash have been reported as high as nearly 59,000 pmoles/dscm (12,000 ng/dscm) in a laboratory combustion system. Such formation has been related directly to poor combustion conditions, noted by the emission of soot from the flame, with the source of the carbon directly linked to the fuel. Higher emissions of PCDDs/Fs compared to normal facility operations associated with the start-up (during and for a short period thereafter) of some full-scale combustion facilities, when soot from natural gas or fuel oil is present, have also been reported. The purpose of this study was to assess the importance of flame soot (including adsorbed/condensed aromatics) versus vapor-phase flame products in PCDD/F formation from the products of an ethylene diffusion flame in the presence of gas-phase chlorine.
Ryan, S.; Wikstrom, E.; Gullett, B.; Touati, A. 2004. Investigation of the pathways to PCDDs/Fs from an Ethylene Diffusion Flame: Formation from Soot and Aromatics. Organohalgen Compounds 66:1119-1125.