Clean Air Act, 1990 amendments

Although the majority of molecules in cmde oils and refined products are hydrocarbons, the U.S. Clean Air Act amendment of 1990 mandated the addition of oxygenated compounds to gasoline in many parts of the United States. The requirement is usually that 2% (w/w) of the fuel be oxygen, which... 

Large sources of SO2 and NO may also require additional emission reductions because of the 1990 Clean Air Act Amendments. To reduce acid... 

Since SO2 and NO2 are criteria pollutants, their emissions are regulated. In addition, for the purposes of abating acid deposition in the United States, the 1990 Clean Air Act Amendments require that nationwide SO2 and NO emissions be reduced by approximately 10 million and 2 million t/yr, respectively, by the year 2000. Reasons for these reductions are based on concerns which include acidification of lakes and streams, acidification of poorly buffered soils, and acid damage to materials. An additional major concern is that acid deposition is contributing to the die-back of forests at high elevations in the eastern United States and in Europe. 

In 1976 the United States banned the use of CFCs as aerosol propellants. No further steps were taken until 1987 when the United States and some 50 other countries adopted the Montreal Protocol, specifing a 50% reduction of fully halogenated CFCs by 1999. In 1990, an agreement was reached among 93 nations to accelerate the discontinuation of CFCs and completely eliminate production by the year 2000. The 1990 Clean Air Act Amendments contain a phaseout schedule for CFCs, halons, carbon tetrachloride, and methylchloroform. Such steps should stop the iacrease of CFCs ia the atmosphere but, because of the long lifetimes, CFCs will remain ia the atmosphere for centuries. 

The Clean Air Act Amendments of 1990 limit the amount of benzene in gasoline in the United States to 1% (7). Initially there was some concern that this would dismpt the benzene supply and demand balance in the chemical industry because at that time gasoline contained benzene above 1%. If refiners had to extract all of the benzene above 1%, substantial additional benzene would be produced. However, only modest increases in the quantity of benzene produced from reformer sources is expected as most refiners can adjust the composition of reformer feed and reformer severity to produce less benzene. 

In the United States, the Clean Air Act of 1970 imposed limitations on composition of new fuels, and as such methanol-containing fuels were required to obtain Environmental Protection Agency (EPA) waivers. Upon enactment of the Clean Air Act Amendments of 1977, EPA set for waiver unleaded fuels containing 2 wt % maximum oxygenates excluding methanol (0.3 vol % maximum). Questions regarding methanol s influence on emissions, water separation, and fuel system components were raised (80). 

The 1990 Clean Air Act Amendments Hst 189 hazardous air pollutants (HAPs) that the EPA must regulate to enforce maximum achievable control technology (MACT) to standards which are to be set by the year 2000. The 33/50 project calls for reduction of emissions of 17 specified solvents to predetermined levels by 1995. The SARA statute provides a mechanism by which the community can be informed of the existence, quantities, and releases of toxic chemicals, and requires that anyone releasing specific toxic chemicals above a threshold level to annually submit a toxic chemical release form to the EPA. The status of various ketones under these regulations is shown in Table 4. 

Because of its low sulfur content, lignite is becoming mote important. The U.S. Clean Air Act Amendments of 1990 have resulted in economic premiums fotlow sulfur coal corresponding to 10/t for emission allowances at 500/t of SO2 (32). 

Emissions control systems play an important role at most coal-fired power plants. For example, PC-fired plants sited in the United States require some type of sulfur dioxide control system to meet the regulations set forth in the Clean Air Act Amendments of 1990, unless the boiler bums low sulfur coal or benefits from offsets from other highly controlled boilers within a given utiUty system. Flue-gas desulfurization (FGD) is most commonly accomphshed by the appHcation of either dry- or wet-limestone systems. Wet FGD systems, also referred to as wet scmbbers, are the most effective solution for large faciUties. Modem scmbbers can typically produce a saleable waUboard-quaUty gypsum as a by-product of the SO2 control process (see SULFURREMOVAL AND RECOVERY). 

The two main federal agencies involved in the protection of human health and the environment are the Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA). EPA s principal concern is the protection of the environment, in most cases, the area outside of an industrial faciUty. There are 10 regional offices that carry out the regulatory functions of the agency (Table 1). Primary laws covered by EPA are the Clean Air Act Amendments (CAAA), the Clean Water Act (CWA), Resource Conservation and Recovery Act (RCRA), Comprehensive Environmental Response, Compensation, and LiabiUty Act (CERCLA), Toxic Substances Control Act (TSCA), and Eederal Insecticide, Eungicide, and Rodenticide Act (FIFRA). 

Various laws have been passed in the United States to control air pollution. The first law that had any real effect was the Clean Air Act of 1970 (CAA), which was followed by the Clean Air Act Amendments of 1977. Most recentiy, the Clean Air Act Amendments (CAAA) of 1990 (5) further changed and updated the requirements. 

Clean Air Act Amendments Update UtiLty NO Regulations," EPRI NO Control Workshop, Scottsdale, Ariz., May 1994. 

Glean Air Act as Amended in 1990. The Clean Air Act Amendments of 1990 represent a mote recent effort by the U.S. Congress to address clean air concerns. The first Clean Air Act, passed ia 1967, provided authority to estabUsh air quaUty standards. Further legislation passed ia 1970, 1974, and 1977 extended and modified the original act. The seven tides of the 1990 Act not only extended previous measures, but also broke new conceptual ground. 

Tide V of the Clean Air Act Amendments of 1990 covers federally approved state operating permits for manufacturing faciUties. One requirement of this regulation is that manufacturers must report emissions information of identified ha2ardous air pollutants specific to thein operation from a list of 189 named in the Clean Air Act Amendments. Rubber and tine manufacturers had to meet this requirement by the end of 1995. The Rubber Manufacturers Association has begun an industrywide project to develop accurate and reliable emissions data to aid manufacturers to comply with these requinements (44). 

Concern over the release of hazardous trace elements from the burning of coal has been highlighted by the 1990 Clean Air Act Amendments. Most toxic elements are associated with ash-forming minerals in coal (5). As shown in Table 1, levels of many of these toxic metals can be significantly reduced by physical coal cleaning (6). 

U.S. Clean Air Act Amendments, PubHc Law 101-549, Tide 3, Hazardous Air Pollutants, U.S. Government Printing Office, Washington, D.C., 1990. 

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