Pattern Change of Several Polycyclic Aromatic Furans and Analogous Thiophenes on Oxidative Pyrolysis of Pitches in Flue Gases, and the Relevance to their Quantitative Analysis

Abstract

Coal tars, coal-tar pitches, and ring-furnace flue gases have been analyzed by GC–MS for several classes of polycyclic aromatic furans and thiophenes and concentration patterns were obtained for benzonaphthofurans, benzonaphthothiophenes, benzobisbenzofurans, and their isomers. During formation of tar in a coke oven battery non-peripheral and alternating polycyclic thiophenes are formed preferentially. Peripheral polycyclic furans were not found in any of the materials. During tar processing the concentrations of minor fractions of peripheral benzonaphthothiophene isomers are reduced substantially. A further reduction occurs during pitch carbonization under oxidative conditions in an annular baking furnace. This largely facilitates quantification of the non-peripheral compounds.