Source Control of Particulate Emissions

Boubel, R. W., "Control of Particulate Emissions from Wood-Fired Boilers," Stationary Source Enforcement Series, EPA 340/1-77-026. U.S. Environmental Protection Agency, Washington, DC, 1977. 

There are many types of emissions to atmosphere, and these can be characterized as particulate (solid or liquid), vapor and gaseous. Overall, the control of atmospheric emissions is difficult because the majority of emissions come from small sources that are difficult to regulate and control. Legislators therefore control emissions from sources that are large enough to justify monitoring and inspection. Industrial emissions of major concern are as follows. 

E. Bakke, "The AppHcation of Wet Electrostatic Precipitators for Control of Eiue Particulate Matter," Preprint, Symposium on Control of Tine Particulate Emissions from Industrial Sources, Joint U.S.-USSR Working Group, Stationay Source Air Pollution ControlTechnology, San Francisco, Calif, Jan. 15—18, 1974. 

EPA is required to issue guidance on reasonably available control measures (RACM) and best available control measures (BACM) for other sources of particulate matter emissions. 

To gather information which will enable selection of appropriate control equipment. If a source test determines that the emission is 3000 mg of particulate per cubic meter and that it has a weight mean size of 5 p.m, a control device must be chosen which will collect enough particulate to meet some required standard, such as 200 mg per cubic meter. (4) To determine the efficiency of control equipment installed to reduce emissions. If a manufacturer supplies a device guaranteed to be 95% efficient for removal of particulate with a weight mean size of 5 /rm, the effluent stream must be sampled at the inlet and outlet of the device to determine if the guarantee has been met. 

Replace old boilers - Older refinery boilers can be a significant source of SO, NO, and particulate emissions. It is possible to replace a large number of old boilers with a single new cogeneration plant with emissions controls. 

EPA, 1982. U.S. EPA, Office of Air Quality Planning and Standards, "Control Techniques for Particulate Emissions from Stationary Sources, Volume 1," EPA-450/3-81-005a, Research Triangle Park, NC, September, 1982. 

The first essential step in the design of a fume control system and selection of gas-cleaning equipment is the characterization of the fume emission source. Design procedures which can be used for new and existing industrial plants follow. The characterization of fume emission sources includes parameters such as plume flow rates (mVs), plume geometry (m), source heat flux (J/s), physical and chemical characteristics of particulates, fume loadings (mg/m ), etc. 

Figure 17-46 shows such a performance curve for the collection of coal fly ash by a pilot-plant venturi scrubber (Raben "Use of Scrubbers for Control of Emissions from Power Boilers, United States-U.S.S.R. Symposium on Control of Fine-Particulate Emissions from Industrial Sources, San Francisco, 1974). The scatter in the data reflects not merely experimental errors but actual variations in the particle-size characteristics of the dust. Because the characteristics of an industrial dust vary with time, the scrubber performance curve necessarily must represent an average material, and the scatter in the data is frequently greater than is shown in Fig. 17-46. For best definition, the curve should cover as wide a range of contacting power as possible. Obtaining the data thus requires pilot-plant equipment with the flexibility to operate over a wide range of conditions. Because scrubber performance is not greatly affected by the size of the unit, it is feasible to conduct the tests with a unit handling no more than 170 m3/h (100 ftVmin) of gas.

There is a need today to quantify the effects of aerosol sources on ambient particulate matter loadings. Identifying the major sources of ambient particulate matter loadings was a fairly simple process when values exceeded 500 /ig/m and stack emissions were plainly visible. Control of these emitters was forthcoming and effective. At levels of 150 to 200 fxg/w , the use of annual emission inventories focused further regulatory efforts on major sources which have resulted in more successful reductions. Presently, at levels around 75-100 /ig/m, the uncertainties involved in these assessments of source contributions are greater than the contributions themselves. 

A balance between control of fugative dust emissions and sources of fine particulates is perhaps the most appropriate approach to standard attainment. 

Daisey, J. M., J. L. Cheney, and P. J. Lioy, Profiles of Organic Particulate Emissions from Air Pollution Sources Status and Needs for Receptor Source Apportionment Modeling, J. Air Pollut. Control Assoc., 36, 17-33 (1986b). 

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