The fate of PAHs in the carbon black manufacturing process

This study measured PAHs contained in the feedstock oil, carbon black produ cts, and stack flue gas, then the fate of PAHs was assessed from the mass b alance point of view for a carbon black manufacturing process. Results show the carbon black manufacturing process would result in the depletion of to tal-PAHs and the summation of top three carcinogenic PAH species (i.e., BbF + BaP + DBA) up to 98.15% and 99.83%, respectively. The above results sugg est that the carbon black manufacturing process would result in not only th e decrease of the amount of total-PAHs, but also the carcinogenic potencies of PAHs originally contained in the feedstock oil. Regarding PAHs containe d in the carbon black products and stack flue gas, this study suggest they might be resulted mostly from high-temperature pyrolytic process, rather th an the PAHs originally contained in The feedstock oil. For the carbon black manufacturing industry, since the soot (i.e., the carbon black) was comple tely collected as its final product, therefore most of carbon black-bearing PAHs did not directly release to atmosphere. On the other hand, PAHs conta ined in the stack flue gas were directly exhausted to the atmosphere and th us were assessed in this study. The results show the emission rates for tot al-PAHs and BbF + BaP + DBA for the stack flue gas were 2.18 kg/day and 1.5 0 g/day, respectively, which were approximately 25% and 40% of those exhaus ted from a municipal incinerator with a treatment capacity of 300 metric to ns/day. It is concluded that the carbon black manufacturing process might n ot be a significant PAHs emission Source, as compared to the municipal inci nerator. (C) 2001 Elsevier Science Ltd. All rights reserved.