Gasoline pollution standards

The Clean Air Act of 1990 establishes tighter pollution standards for emissions from automobiles and trucks. These standards will reduce tailpipe emissions of hydrocarbons, carbon monoxide, and nitrogen oxides on a phased-in basis beginning in model year 1994. Automobile manufacturers will also be required to reduce vehicle emissions resulting from the evaporation of gasoline during refueling. 

By using multiple jets, adjustable orifices, and other intricacies, commercial carburetors attain mixture control approximating the desirable performance for a gasoline engine as shown in Fig. I. Increasing air pollution standards have exacted greater demands on carburetor performance and most of these demands have been met by utilizing solid-state controls over carburetor optimization... 

To address air pollution problems, the U.S. Environmental Protection Agency (EPA) proposed and developed new vehicle emissions standards. Ultralow sulfur standards for diesel fuel began in 2006. Gasoline sulfur standards have been phased-in since 2004. The EPA Tier 2 tailpipe emissions regulations for light duty vehicles have already taken effect. Standards have also been developed for heavy-duty vehicles that would be phased in from 2007 to 2010. 

From the straight-run, cracked and reformed gasolines the refiners compound the different mixtures sold as proprietary and regional brands to meet pollution standards. 

The benefits of alcohol fuels include increased energy diversification in the transportation sector, accompanied by some energy security and balance of payments benefits, and potential air quaUty improvements as a result of the reduced emissions of photochemically reactive products (see Air POLLUTION). The Clean Air Act of 1990 and emission standards set out by the State of California may serve to encourage the substantial use of alcohol fuels, unless gasoline and diesel technologies can be developed that offer comparable advantages. 

Hydrogen Internal Combustion Engine. Standard gasoline and diesel-powered internal combustion engine vehicles can be converted to mn on hydrogen. These vehicles have often been found considerably less polluting, safer, and more efficient than their fossil fuel-burning counterparts. 

Because mobile sources of air pollution are capable of moving from one local jurisdiction to another, they are usually regulated by the national government. In the United States, state or local agencies can have more restrictive standards, if they choose. Through 1990, only the state of California had established standards more restrictive than the U.S. federal standards, and these only for gasoline-powered automobiles. 

Gasoline-powered motor vehicles outnumber all other mobile sources combined in the number of vehicles, the amount of energy consumed, and the mass of air pollutants emitted. It is not surprising that they have received the greatest share of attention regarding emission standards and air pollution control systems. Table 25-2 shows the U.S. federal emission control requirements for gasoline-powered passenger vehicles. 

U.S. Environmental Protection Agency. (2000). Control of Air Pollution from New Motor Vehicles Tier 2 Motor Vehicle Emissions Standards and Gasoline Sulfur Control Requirements. Federal Register 65 6698-6870. 

By 2010, Tier 2 standards should further reduce vehicle emissions by extending regulations to larger SUVs and passenger vans. The use of gasoline with a lower sulfur content will also reduce emissions and it also makes it easier to build cars that can achieve further reductions. These standards should allow new U.S. cars to be extremely free of air pollutants. But, the Clean Air Act does not cover vehicle C02 emissions. Many new cars are called near zero emissions by their manufacturers and may have tailpipe emissions cleaner than some urban air. Hydrogen fuel cell vehicles will have almost no emissions besides some water vapor and would be much cleaner. 

Emission studies show that lead is only a small part of the automotive pollution problem. Prior to control, hydrocarbon emissions were more than 40 times and the oxides of nitrogen emissions more than 15 times the emission of the lead compounds. Obviously, however, legislation will result in the eventual elimination of lead from gasoline. The removal of lead, besides eliminating a possible toxic pollutant, simplifies the problem of handling other automotive exhaust pollutants in that catalytic exhaust chambers perform much better in the absence of lead contaminant. All emission standards become particularly severe in 1975 and 1980. The particulate standards are equivalent to 1 gram Pb/gal in 1975 and 0.3 gram Pb/gal in 1980. Since the particulates include all solid materials, tolerable lead levels will be less than indicated above. 

Clean Air Act. The Clean Air Act is administered by the EPA. Although the principal enforcement provisions are the responsibility of local governments, overall administrative responsibility rests with EPA. This act requires criteria documents for air pollutants and sets both national air quality standards and standards for sources that create air pollutants, such as motor vehicles, power plants, and so on. Important actions already taken under this law include standards for the now complete phased-out elimination of lead in gasoline, and the setting of sulfuric acid air emission guidelines for existing industrial plants. 

National Emission Standards for Hazardous Air Pollutants for Industrial Process Cooling Towers National Emission Standards for Gasoline Distribution Facilities (Bulk Gasoline Terminals and Pipeline Breakout Stations)... 

National Emission Standards for Hazardous Air Pollutants Publicly Owned Treatment Works National Emission Standards for Hazardous Air Pollutants for Ferroalloys Production Ferromanganese and Silicomanganese National Emission Standards for Hazardous Air Pollutants Municipal Solid Waste Landfills National Emission Standards for Hazardous Air Pollutants Manufacturing of Nutritional Yeast National Emission Standards for Hazardous Air Pollutants Organic Liquids Distribution (Non-Gasoline)... 

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