Predicting Fire Emissions: Emission Factors
Authored By: D. Sandberg, R. Ottmar, J. Peterson
An emission factor for a particular pollutant of interest is defined as the mass of pollutant produced per mass of fuel consumed (i.e., lbs/ ton in the English system or g/kg as the metric equivalent). Emission factors vary depending on type of pollutant, type and arrangement of fuel and combustion efficiency. The average fire emission factors have a relatively small range and contributes approximately 16 percent of the total error associated with predicting emissions production (Peterson 1987; Peterson and Sandberg 1988). In general, fuels consumed by flaming combustion produce less smoke than fuels consumed by smoldering combustion. Emission factors for several smoke compounds are presented in table 5.1 for the flaming, smoldering, and fire average for generalized fuel types and arrangements. Emission factors can be used by air quality agencies to calculate local and regional emissions inventories or by managers to develop strategies to mitigate downwind smoke impacts. Additional emission factors have been determined for other fuel types and will be available in the future.
Emissions from fires or from points over fires have been observed extensively by researchers since about 1970. The result is a complete set of emission factors for criteria pollutants and many hazardous air pollutants for most important fuel types. These are available in several publications (for example, Battye and Battye 2002, EPA 1972, Hardy and others 2001, Ward and others 1989) and are not reproduced here.
Less complete compilations of emission factors are for particulate matter components such as size class distribution, elemental and organic carbon fractions, and particulate hazardous air pollutants; and for methane, ammonia, aldehydes, compounds of nitrogen, volatile organic hydrocarbons, and volatile hazardous air pollutants (for example, Battye and Battye 2002, Goode and others 1999, Goode and others 2000, Lobert and others 1991, McKenzie and others 1994, and Yokelson and others 1996).
- Battye, William; Battye, Rebecca. 2002. Development of emissions inventory methods for wildland fire. Final report. Contract 68-D-98-046. Research Triangle Park, NC: U.S. Environmental Protection Agency.
- Goode, J.G.; Yokelson, R.J.; Susott, R.A.; Babbitt, R.E.; Ward, D.E. Davies, M.A.; Hao, W.M. 2000. Measurements of excess O3, CO2 CO, CH4, C2H4, C2H2, HCN, NO, NH3, HCOOH, CH3COOH, HCHO, and CH3OH in 1997 Alaskan biomass burning plumes by airborne Fourier transform infrared spectroscopy (AFTIR). Journal of Geophysical Research. 105: 22,147.
- Goode, J.G.; Yokelson, R.J.; Susott, R.A.; Ward, D.E. 1999. Trace gas emissions from laboratory biomass fires measured by open-path Fourier transform infrared spectroscopy: fires in grass and surface fuels. Journal of Geophysical Research. 104.
- Hardy, C.C.; Hermann, S.M; Mutch, R.E. 2001. Smoke management guide for prescribed and wildland fire. Boise, ID: National Wildfire Coordination Group, Fire Use Working Team. 11 p.
- Lobert, J.M.; Scharffe, D.H.; Hao, W.M.; Kuhlbusch, T.A.; Seuwen, R.; Warneck, P.; Crutzen, P.J. 1991. Experimental evaluation of biomass burning emissions: Nitrogen carbon containing compounds. In: Levin, J.S., ed. Global biomass burning: Atmospheric, climatic, and biospheric implications. Cambridge, MA: MIT Press: 569 p.
- McKenzie, L.; Hao, W.M.; Richards, G.; Ward, D. 1994. Quantification of major components emitted from smoldering combustion of wood. Atmospheric Environment. 28(20).
- Peterson, Janice L. 1987. Analysis and reduction of the errors of predicting prescribed burn emissions. Seattle: University of Washington. 70 p p. M.S.
- Peterson, Janice L.; Sandberg, David V. 1988. A national PM10 emissions inventory approach for wildfires and prescribed fires. In: Mathai, C.V.; Stonefield, David H., eds. Transactions PM-10 implementation of standards: an APCA/EPA international specialty conference. Pittsburgh, PA: Air Pollution Control Association.
- U.S. Environmental Protection Agency. 1972. Compilation of air pollutant emission factors. OAP Publ. AP-42. Research Triangle Park, NC: U.S. Environmental Protection Agency.
- Ward, D.E.; Hardy, C.C.; Sandberg, D.V.; Reinhardt, T.E. 1989. Part III-emissions characterization. In: Sandberg, D.V.; Ward, D.E.; Ottmar, R.D., comp. eds. Mitigation of prescribed fire atmospheric pollution through increased utilization of hardwoods, piled residues, and long-needled conifers. Final report. U.S. DOE, EPA. Seattle, WA: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station.
- Yokelson, R.J.; Griffith, D.W.T.; Ward, D.E. 1996. Open-path Fourier transform infrared studies of large scale laboratory biomass fires. Journal of Geophysical Research. 101(D15).
