3.0 CONTROL OF SULFUR COMPOUND EMISSIONS 3.1 Fuel combustion. It is not possible to make nationally applicable generalizations about attainable degrees of control of sulfur oxides emissions from combustion sources. Availability of low-sulfur fuels varies from one area to another. In some areas, severe restrictions on the sulfur content of fuels could have a significant impact on fuelsupply patterns; accordingly, where such restrictions are necessary for attainment of national ambient air quality standards, adoption of phased schedules of sulfur-infuel limitations is recommended. Stack gas cleaning is feasible at large industrial combustion sources and steam electric power plants. Technology has been demonstrated which will allow 70 percent removal of sulfur oxides from combustion gases of most existing fuel burning units. Alternative means of meeting requirements for the control of sulfur oxides emissions from fuel combustion sources include: Use of natural gas, distillate oil, low-sulfur coal, and low-sulfur residual oil; desulfurization of oil or coal; stack gas desulfurization; and restricted use, shutdown, or relocation of large existing sources. It is technically feasible to produce or desulfurize fuels to meet the following specifications: Distillate oil-0.1 percent sulfur (though it should be noted that distillate oil containing less than 0.2 percent sulfur is not generally available at this time); residual oil-0.3 percent sulfur; bituminous coal-0.7 percent sulfur. Availability of significant quantities of such low-sulfur fuels in any region where they do not naturally occur or have not been imported from other domestic or foreign sources will require planning for the timely development of new sources of such fuels. Because residual oil generally is obtained from overseas sources, its use ordinarily is restricted to areas accessible to waterborne transportation. There are limited tonnages of 0.7 percent sulfur coal produced at the present time, primarily in the western United States; large reserves of such coal exist but are not now being mined. The flaring or combustion of any refinery process gas stream or any other process gas stream that contains sulfur compounds measured as hydrogen sulfide can be limited to a concentration of 10 grains per 100 standard cubic feet (23 gm/100scm) of gas This limitation on combustion of process gas relates to the control of sulfur oxide emissions that would result from burning untreated process gas from refinery operations or coke ovens containing hydrogen sulfide and other sulfur compounds. Hydrogen sulfide emissions can be controlled by requiring incineration or other equally ef fective means for all process units. Approx mately 95 to 99 percent of the sulfur compounds must be removed from the process gas stream to meet this emission limitation. It may be appropriate to consider exemption of very small units which economically may not be able to achieve this level of control. 3.2 Sulfuric acid plants. The emissions of sulfur dioxide from sulfuric acid plants can be limited to 6.5 pounds per ton (3.25 kg./ metric ton) of 100 percent acid produced. This emission limitation is equivalent to an overall SO, to SO, conversion efficiency of 99.5 percent or a stack gas concentration of about 250 to 550 p.p.m. of sulfur dioxide, by volume, depending on the strength of the feed gas. 3.3 Sulfur recovery plants. The emission of sulfur oxides, calculated as sulfur dioxide, from a sulfur recovery plant can be limited to 0.01 pound (kg.) per pound (kg.) of sulfur processed. Approximately 99.5 percent of the sulfur processed must be recovered to meet this limitation. Existing plants typically recover 90 to 97 percent of the sulfur. This emission limitation corresponds to a sulfur dioxide concentration of about 1,300 p.p.m., by volume. 3.4 Nonferrous smelters. Technology is available to limit emission of sulfur oxides. calculated as sulfur dioxide, from primary nonferrous smelters according to the following equations: Copper smelters: Y=0.2X. Zinc smelters: Y=0.564X8 Where: X=Total sulfur fed to smelter (lb./hr.). These emission limitations are equivalent to removal of about 90 percent of the inputsulfur to the smelter for most copper smelters and somewhat higher for most lead and zinc smelters. Technology capable of achieving such emission limitations may not be applicable to all existing smelters. In such cases, less restrictive control can be coupled with restricted operations to achieve air quality standards. 3.5 Sulfite pulp mills. The total sulfite ulp mill emissions of sulfur oxides, calcuated as sulfur dioxide, from blow pits, washer vents, storage tanks, digester relief, nd recovery system, can be reduced to 9 ounds per air-dried ton (4.5 kg./metric ton) f pulp produced. This emission limitation as application only to those sulfite mills hat install waste liquor recovery systems or water pollution control or other purposes. The installation of a recovery system can result in significant sulfur oxides emissions if not properly designed. For sulfite mills with existing recovery systems, a sulfur oxides emission limitation of 20 pounds per air-dried ton (9 kg./metric ton) of pulp may be more reasonable due to economic considerations. 4.0 CONTROL OF ORGANIC COMPOUNDS The following emission limitations are applicable to the principal stationary source of organic compound emissions. Reducing total organic compound emissions will reduce ozone formation. Such control of organic compound emissions may appropriately be considered in areas where application of the Federal motor vehicle emission standards will not produce the emission reductions necessary for attainment and maintenance of the national ambient air quality standards for ozone. These emission limitations emphasize reduction of total organic compound emissions, rather than substitution of "nonreactive" or "less reactive" organic compounds for those already in use, because there is evidence that very few organic compounds are photochemically nonreactive. Substitution may be useful, however, where it would result in a clearly evident decrease in reactivity and thus tend to reduce ozone formation. The extent to which application of these emission limitations would reduce ozone formation in a given air quality control region will depend on the "mix" of emission sources in the region. These limitations are separable, i.e., one or more portions can be considered, as necessary. 4.1 Storage of volatile organic compounds. The storage of volatile organic compounds in any stationary tank, reservoir or other container of more than 40,000 gallons (150,000 liters) can be in a pressure tank capable of maintaining working pressures sufficient at all times to prevent vapor or gas loss to the atmosphere. If this cannot be done, the tank can be equipped with a vapor loss control device such as: (a) A floating roof, consisting of a pontoon type, double deck type roof or internal floating cover, which will rest on the surface of the liquid contents and be equipped with a closure seal or seals to close the space between the roof edge and tank wall. This control equipment may not be appropriate if the volatile organic compounds have a vapor pressure of 11 pounds per square inch absolute (568 mm. Hg) or greater under actual storage conditions. All tank gauging or sampling devices can be gas-tight except when tank gauging or sampling is taking place. (b) A vapor recovery system, consisting of a vapor gathering system capable of collecting the volatile organic compound vapors and gases discharged, and a vapor disposal system capable of processing such volatile organic vapors and gases so as to prevent their emission to the atmosphere and all tank gauging and sampling devices can be gas-tight except when gauging or sampling is taking place. These emission limitations are not intended for application to underground tanks used for long-term storage, where filling operations occur frequently. The storage of any volatile organic compound in any stationary storage vessel more than 250-gallon (950 liter) capacity can be in a vessel equipped with a permanent submerged fill pipe or fitted with a vapor recovery system. This emission limitation will reduce volatile organic emissions 90 to 100 percent from uncontrolled sources of storage in vessels 40,000 gallon capacity or greater and approximately 40 percent from uncontrolled sources of storage in vessels 250 gallon capacity or greater. 4.2 Volatile organic compounds loading facilities. The loading of volatile organic compounds into any tank, truck, or trailer having a capacity in excess of 200 gallons (760 liters) can be from a loading facility equipped with a vapor collection and disposal system. Also, the loading facility can be equipped with a loading arm with a vapor collection adaptor, pneumatic, hydraulic or other mechanical means to force a vaportight seal between the adaptor and the hatch. A means can be provided to prevent drainage of liquid organic compounds from the loading device when it is removed from the hatch of any tank, truck, or trailer, or to accomplish complete drainage before the removal. When loading is effected through means other than hatches, all loading and vapor lines can be equipped with fittings which make vapor-tight connections and which close automatically when disconnected. This emission limitation will result in 55 to 60 percent reduction in volatile organic emissions from uncontrolled sources in gasoline marketing and other organic transfer operations. 4.3 Volatile organic compounds water separation. Single or multiple compartment volatile organic compounds water separators which receive effluent water containing 200 gallons (760 liters) a day or more of any volatile organic compound from any equipment processing, refining, treating, storing or handling volatile organic compounds having a Reid vapor pressure of 0.5 pound or greater can be equipped with one of the following vapor loss control devices, properly installed in good working order and in operation: (a) A container having all openings sealed and totally enclosing the liquid contents. All gauging and sampling devices can be gastight except when gauging or sampling is taking place. (b) A container equipped with a floating roof, consisting of a pontoon type, double deck type roof, or internal floating cover, which will rest on the surface of the contents and be equipped with a closure seal or seals to close the space between the roof edge and container wall. All gauging and sampling devices can be gas-tight except when gauging or sampling is taking place. (c) A container equipped with a vapor recovery system consisting of a vapor gathering system capable of collecting the organic vapors and gases discharged and a vapor disposal system capable of processing such organic vapors and gases so as to prevent their emission to the atmosphere and with all container gauging and sampling devices gastight except when gauging or sampling is taking place. This emission limitation will reduce organic compound emissions from uncontrolled waste water separator units approximately 95 to 100 percent. 4.4 Pumps and compressors. All pumps and compressors handling volatile organic compounds can be equipped with mechanical seals or other equipment of equal efficiency. 4.5 Waste gas disposal. Any waste gas stream containing organic compounds from any ethylene producing plant or other ethylene emission source can be burned at 1,300° F. (704 C.) for 0.3 second or greater in a direct-flame afterburner or an equally effective device. This does not apply to emergency reliefs and vapor blowdown systems. The emission of organic compounds from a vapor blowdown system or emergency relief can be burned by smokeless flares, or an equally effective control device. This emission limitation will reduce organic compound emissions approximately 98 percent. 4.6 Organic solvents. The emission of organic compounds of more than 3 pounds (1.3 kg.) per hour or 15 pounds (6.8 kg.) per day from any equipment can be reduced by at least 85 percent. This can be accomplished by: (a) Incineration, provided that 90 percent or more of the carbon in the organic compounds being incinerated is oxidized to carbon dioxide, or (b) Carbon adsorption. This limitation can be applied to a variety of solvent users including industrial surface coatings, dry cleaning, degreasing and printing operations. Surface coating operations may appropriately be exempted from this limitation when the coating's solvent makeup is water-based and does not exceed 20 percent of organic compounds by volume. Organic solvents which have been shown to be virtually unreactive in the formation of ozone, e.g., saturated halogenated hydrocarbons, perchlorethylene, benzene, acetone. and C1-C, n-paraffins also may be considered for exemption. Other compounds which have been shown to have low reactivity include cyclohexanone, ethyl acetate, diethylamine, isobutyl acetate, isopropyl alcohol methyl benzoate, 2-nitropropane. pheny acetate and triethylamine. This emission limitation may impose an economic burden upon some paint spray booth installations. If such sources are not major contributors to hydrocarbon pollution levels, they may appropriately be considered for exemption. 4.7 Architectural coatings for buildings. The emission of organic compounds from architectural coatings can be reduced by requiring the use of water-base or other coatings having an organic solvent content of less than 20 percent by volume. The effectiveness of the limitations set forth in seetions 4.6 and 4.7 will vary, depending on the nature and amounts of emissions in an area a rough estimate based on Los Angeles emission data indicates that application of the limitation would result in a 70 percent reduction in organic solvent emissions. In estimating the effectiveness, it should be assumed that all organic emissions are reactive; use of exempt solvents as substitutes for regulated solvents may be considered 100 percent effective in reducing reactive organic solvent emissions. 5.0 CONTROL OF CARBON MONOXIDE EMISSIONS The emissions of carbon monoxide can be limited by requiring complete secondary combustion of waste gas generated in such operations as a grey iron cupola, blast fur nace, basic oxygen steel furnace, catalyst regeneration of a petroleum cracking system, petroleum fluid coker or other petroleum process. 6.0 CONTROL OF NITROGEN OXIDES EMISSIONS 6.1 Fuel burning equipment. The emis sion of nitrogen oxides, calculated as nitrogen dioxide, from gas-fired fuel burning equipment can be limited to 0.2 pound per million B.t.u. (0.36 gm/10 gm-cal) of heat input. This emission limitation is about equivalent to a nitrogen dioxide concentration of 175 p.p.m., by volume, on a dry basis at 3 percent oxygen and represents about a 50 percent reduction in nitrogen oxide emis sions from uncontrolled gas-fired equip. ment. The emission of nitrogen oxides, calculated as nitrogen dioxide, from oil-fired fuel burning equipment can be limited to 0.30 pound per million B.t.u. (0.54 gm/106 gmcal) of heat input. This emission limitation is about equivalent to a nitrogen dioxide concentration of 230 p.p.m., by volume, on a dry basis, at 3 percent oxygen and represents about a 50 percent reduction in nitrogen oxide emissions from uncontrolled oilfired fuel burning equipment. 6.2 Nitric acid manufacture. The emission of nitrogen oxides, calculated as nitrogen dioxide, from nitric acid manufacturing plants can be limited to 5.5 pounds per ton (2.8 kg./metric ton) of 100 percent acid produced. This emission limitation is about equivalent to a nitrogen dioxide concentration of 400 p.p.m., by volume. [36 FR 22398, Nov. 25, 1971, as amended at 36 FR 25233, Dec. 30, 1971] 'Major sources of sulfur oxides and/or particulate matter. |