An earlier demonstration that the relative concentrations of isomers of polychlorinated dibenzofuran do not vary as the flamefront of an iron ore sinter plant progresses through the bed, and profiles are similar for two sinter strands has been widened to include studies of the similarity or otherwise between full scale strand and sinter pot profiles, effect of addition of suppressants and of coke fuel substitution with other combustible materials. For dioxin suppressant addition, a study of the whole of the tetra- penta- and hexaCDF isomer range as separated by the DB5MS chromatography column, indicates no significant change in profile: examination of the ratios of the targeted penta- and hexaCDF isomers suggests the profile is similarly unaffected by coke fuel replacement. Addition of KCl at varied levels has also been shown to have no effect on the 'fingerprint' and there is no indication of any effect by the composition of the sinter mix.
View Article and Find Full Text PDFPlastics are potentially suitable for the removal of vapour phase PCDD/Fs in emissions from the electric arc furnace (EAF) steelmaking process. Three different commercial plastics, i.e.
View Article and Find Full Text PDFThe difficulty in measuring the heats of combustion of polychlorinated dibenzofurans (PCDFs) has resulted in a shortage of data on their heats of formation, required for the purpose of developing an understanding of the role of thermodynamics and kinetics in their production via industrial processes. B3LYP density functional theory calculations have been carried out on a number of PCDFs using 6-31G(d) and 6-311+G(3df,p) basis sets to estimate their heats of formation based on the known experimental values for dibenzofuran, benzene and chlorobenzene. By examining the interactions among chlorine substituents, it is shown that energy contributions arising from successive chlorination can be interpreted in a predictable way, based on a small number of key energy parameters associated with ring position and chlorine atom repulsions.
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