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Show • Combustion gas velocity • Particle size distribution and loading at the inlet to the air pollution control system • Gas temperature at the APCD The present thennodynamic database pennits reasonable predictions of the toxic metals emissions from coal-fired combustion equipment. This has lead to a better understanding not only of the species responsible for fugitive emissions of these toxic metals, but also of the conditions responsible for variability in emissions from one combustor to another. It had been known experimentally that volatile lead emissions increase in the presence of chlorine. However, the impact of small changes in APCD temperature on volatility of key HAPs had not previously been considered. It is possible that further improvements in the thennodynamic database for volatile metal species will continue to improve our understanding of the toxic metals partitioning process. As well, our future understanding of these processes will likely lead to improved strategies for control of air toxics emissions from coal and other combustion processes. Data collected on emissions of organic HAPs, including PCDDIF, suggest that these compounds may not be present in concentrations of significance from either a regulatory or health-risk perspective. For the most part organic species were either unmeasureable due to non-detects on the samples analyses, or were measured at concentrations low enough to be of no concern. References [1] Barton, R. G., W. D. Clark, W. S. Lanier and W. R. Seeker. "Dioxin Emissions from Waste Incinerators," Dioxin 89, Toronto, Canada, Sept. 1989, Chemosphere, Vol 20., p 1817, 1990. [2] Gullett, B.K., Raghunathan, K., and Bruce, K.R. "Reduction of Chlorinated Organics by Coal Co-Firing" Technical Report, Illinois Clean Coal Institute, Carterville, IL, 3 April 1995. [3] Removing the Hazards from Coal's Hazardous Air Pollutants. PETC Review, Spring 1995. Office of Fossil Energy, U.S. Department of Energy, Pittsburgh Energy Technology Center, Pittsburgh, P A. pp 6-17. [4] Barton, R.G., Maly, P.M., Clark, W.D., Seeker, W.R. and Lanier, W.S., 1988. Prediction of the Fate of Toxic Metals in Hazardous Waste Incinerators, Final Report. EPA Contract: 68- 03-3365, U.S. Environmental Protection Agency, Washington, D.C. [5] Barton, R.G., Clark, W.D. and Seeker, W.R., 1990. Fate of metals in waste combustion systems. Combust. Sci. and Tech., 74: 327-342. 13 |
