Abstract
Evolution of soot and polycyclic aromatic hydrocarbons (PAH), especially benzo (a) pyrene (BaP) which was used as an indicator of PAHs, was determined when polymers, and low molecular weight hydrocarbons which are close in structure to decomposition products of polymers were combusted or pyrolyzed under different conditions.
It was found that BaP was not always accompanied with soot, because it was produced even at non-sooting temperature of 900°C or so in nitrogen atmosphere. PAHs are considered to be part of the intermediates for soot, because their production during combustion and pyrolysis is considerable and at least BaP production decreases at over 1000 - 1100°C even in nitrogen atmosphere. Both soot and BaP formations themselves are temperature-dependent, but not oxygen dependent, although the products can be destructed by oxygen afterward. The production of soot from such mixture as benzene and methanol was much less than that from benzene alone. It indicates that hydrogen evolved in decomposition serves to retard soot formation.
© 1984 Center for Fire Science and Technology, Research Institute for Science and Technology, Tokyo University of Science