WSP04580 - Laserfiche WebLink

Home Browse Search

, ~,." ' :.-.-,_...-";"".-':.. OS2:T DivIsion: Air Pollution Control J}1vlsion James H. Lents. Director the added advantage of appearing suitable for dry scrubbing of 502. the technique of injecting an S02-abaorblng so11d into the boiler or bot gas stream. then collectIng the solid (and absorbed 802) in the fabric fUter. Reactive VOC emissions can be reduced by substituting water-based or non-reactive VOC for the reactive eoapounda. Add-on cout.rol devIces are also available; if the exhaust gas contains enough VOC. an adsorption or coodeasiDg control systea ., even pay for itself by colleet1ns sufficIent quantities of an expensive VOC for reuse. MOx add~n control devices ex1st. but are coatly to purchase and operate; efforts to date have been concentrated on 10v-NOx: desIgns. CO can be burned to C02. but often the gas strea. CO (and other c~tible IISterial) concentration is so low that afterburner fuel cost is prohibitive; add-on control devices again are costly. For all euept tbe hazardous pollutants and a few non-criteria pollutants emitted from specific new sources. alllost no control of other- pollutauta Is either required by regulation or applied by the owner/operator. In addition. the emphasis on particulate matter control baa shifted to the aore dangerous to health and acre difficult to control fine particulate (PH 10) portion of the total particulate Ratter (PHI) em1sious. HOst of the remaining nearly 200.000 tons per year of PKl' is PH 10. Control of the nontraditional air pollution sources presents additional cOllplictlons. fugitive -emasioQ sources. BUch -as cleared land. stockpiles. and, refinery valve leaks, ,do not have ducts ,or_ ,stacks with lih1.ch to, chanuel pollutants to a control device. For 'these sources, control.is achieved by applying control ....easures ranging from wateriog to stringnet aa1ntenance schedules to stop leaks. Other sources. such as home heating units. are si.ply too small to justify most add-on control devIces econoDdeally. Clean fuels. lo'W'-pollutlon designs, and - in some cases - catalytic cleaners provide the only control strategIes. There are three somewhat overlapping areas of concern in air quality management: 1. Impacts immediately adjacent to the source (i.e.. at the source's property boundary). Fugitive ealssions and emissions from low stacks and building vents produce ambient afr impacts that are highest near the source. but which generally decrease rapidly with distance. Protection of the welfare (property value. quality of life) and health of citizeaa in surrounding residencesJ offices, schools. and other structures is of primary concern. 2. Impacts which alone or in combination with other sources can cause exceedances of allowable incremental deterioration of air quality, NAAQS. or of levels considered safe for the general populationo Such upacts usually occur In areas when there are a large number of sources of the same pollutant. where there Is inadequate dispersion of the polluted air or a coabination of both. generally occurring within 50 km of the source. 3. Impacts which occur on a large scale as emlssons of a pollutant continue to increase. these effects may be on a regional or even national scale and include visibility impairment and acid deposition. Each of these concerns may require different levels of control. Not only must certain levels of control he required. hut air quality aaaageaent aust ensure that these emission levels are met continuously. The methods used to maintain compliance are: -32- - - - - - - - - - - - - - - - - - .. -