Pollution motor vehicle

W. Carter, Ocyone Reactivity Analysis of Emissionsfrom Motor Vehicles, (Draft Report for the Western Liquid Gas Association), Statewide Air Pollution Research Center, University of California at Riverside, July 11, 1989. 

The behavior of these pollution roses is intuitively plausible, because considerable hydrocarbon emissions come from motor vehicles which are operated in both winter and summer and travel throughout the urban area. On the other hand, sulfur dioxide is released largely from the burning of coal and fuel oil. Space heating emissions are high in winter and low in summer. The SO2 emissions in summer are probably due to only a few point sources, such as power plants, and result in low average concentrations from each direction as well as large directional variability. 

While motor vehicles built today emit fewer pollutants (60% to 80% less, depending on the pollutant) than those built in the 1960s, cars and trucks still account for almost half the emissions of the ozone precursors VOCs and NO, and up to 90% of the CO emissions in urban areas. The principal reason for this problem is the rapid growth in the number of vehicles on the roadways and total miles driven. 

In view of the unforeseen growth in automobile emissions in urban areas combined with the serious air pollution problems in many urban areas, the Congress has made significant changes to the motor vehicle provisions on the 1977 Clean Air Act. 

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, Final Rule, Control of Air Pollution From New Motor Vehicles and New Motor Vehicle Engines Refueling Emission Regulations for... 

Catalytic Converter an air pollution abatement device that removes pollutants from motor vehicle exhaust either by oxidizing them into carbon dioxide and water or reducing them to nitrogen. A typical catalytic oxidizer for auto emission control is illustrated in the sidebar figure. 

Outdoor air is generally less polluted than the system return air. However, problems with reentry of previously exhausted air occur as a result of improperly located exhaust and intake vents or periodic changes in wind conditions. Other outdoor contamination problems include contaminants from other industrial sources, power plants, motor vehicle exhaust, and dust, asphalt vapors, and solvents from construction or renovation. Also, heat gains and losses through the building envelope due to heat conduction through exterior walls, floor, and roof, and due to solar radiation and infiltration, can be attributed to effects from external sources. 

Eaiz, A. Weaver, C. Walsh, M. (1996). Air Pollution from Motor Vehicles. New York The World Bank. 

Cannon, R. E. (1998). The Gas Processing Industry Origins and Evolution, 2nd ed. Tulsa Gas Processors Association. Delucclii, M. A. (1998). LPG for Motor Vehicles A Total Fuel Cycle Analysis of Emissions of Urban Air Pollutants and Greenhouse Gases, prepared for the Propane Vehicle Council and the Propane Education Research Council, Washington, DC. 

Air pollution is principally a problem in urban and heavily industrialized areas, where the flow of clean air from surrounding areas is insufficient to disperse the accumulation. Motor vehicles account for more than 50% of the man-made emissions of carbon monoxide, hydrocarbons, and nitrogen oxides (4). More than half of the U.S. annual trillion vehicle miles are driven in urban areas (5). Nature produces much more pollutants than all man-made sources, but natural emissions are widely dispersed and do not contribute heavily to urban pollution problems (6, 7). 

Serious research in catalytic reduction of automotive exhaust was begun in 1949 by Eugene Houdry, who developed mufflers for fork lift trucks used in confined spaces such as mines and warehouses (18). One of the supports used was the monolith—porcelain rods covered with films of alumina, on which platinum was deposited. California enacted laws in 1959 and 1960 on air quality and motor vehicle emission standards, which would be operative when at least two devices were developed that could meet the requirements. This gave the impetus for a greater effort in automotive catalysis research (19). Catalyst developments and fleet tests involved the partnership of catalyst manufacturers and muffler manufacturers. Three of these teams were certified by the California Motor Vehicle Pollution Control Board in 1964-65 American Cyanamid and Walker, W. R. Grace and Norris-Thermador, and Universal Oil Products and Arvin. At the same time, Detroit announced that engine modifications by lean carburation and secondary air injection enabled them to meet the California standard without the use of catalysts. This then delayed the use of catalysts in automobiles. 

Acid deposition has been known to exist since early in the industrial age. The principle pollutants responsible for the elevated levels of acidity are the oxidized forms of sulphur and nitrogen that have been emitted as by-products from non-ferrous smelters, fossil-fueled power generating stations, and motor vehicles. The pollutants are transported substantial distances from the source areas by the atmosphere. They are deposited on receptor regions remote from the sources as acidic rain, snow, and fog or as gasses and dry particulates. 

One of the most significant Indices of air pollution potential Is provided by statistics on motor vehicle use. On a global scale the number of vehicles continues to rise although the rate of growth has slowed In North America and Europe as a whole, where vehicle densities are the highest In the world. Since 1979, the most rapid growth has occurred In Asia and South America where vehicle ownership has more than doubled (11). In the developing countries, as well as many others, these vehicles are not equipped with emission control devices. 

Carbon monoxide (CO) Is one of the most widely distributed air pollutants. It Is formed by natural biological and oxidation processes, the Incomplete combustion of carbon-containing fuels and various Industrial processes. However, the largest Individual source of man-made emissions Is motor vehicle exhausts which account for virtually all CO emitted In some urban environments. It has been estimated that global man-made emissions range from 300-1600 million tons per year, which Is approximately 60% of the total global CO emissions (22-23). 

Air pollution from exhaust emissions NO t and particulate matter from exhaust emissions causing air pollution are -1% at present. By adoption of better combustion control technology, better quality fuels (or even fuel cell-based motor vehicles), and more efficient catalytic converters, researchers aim to mitigate this problem. 

EPA-Diesel RIA, Regulatory Impact Analysis—Control of Air Pollution from New Motor Vehicles Tier 2 Motor Vehicle Emissions Standards and Gasoline Sulfur Control Requirements United States Environmental Protection Agency, Air and Radiation EPA420-R, 99-023. 1999. December. 

The presence of polycyclic aromatic hydrocarbons in the environment is of obvious concern and, apart from specific occupational environments, human exposure to these compounds derives from combustion products released into the atmosphere. Estimates of the total annual benzo[aJpyrene emissions in the United States range from 900 tons (19) to about 1300 tons (20). These totals are derived from heat and power generation (37-38%), open-refuse burning (42-46%), coke production (15-19%) and motor vehicle emissions (1-1.5%) (19,20). Since the vast majority of these emissions are from stationary sources, local levels of air pollution obviously vary. Benzo[aJpyrene levels of less than 1 pg/1,000 m correspond to clean air (20). At this level, it can be estimated that the average person would inhale about 0.02 pg of benzo[aJpyrene per day, and this could increase to 1.5 pg/day in polluted air (21). 

Research dating back to the mid 1950 s has shown that volatile orgamc compounds (VOC s) photochemically react m the atmosphere and contribute to the formation of ground level ozone, a precursor to smog [1]. Medical studies have shown that human exposure to ozone can result in eye and smus tract irritation, and can lead to respiratory related illnesses [2]. Due to the unique and severe smog problems that affected many cities in the state of California, studies of the causes of ah pollution were initiated m the 1950 s [3]. Based on its findings, California formed the Motor Vehicle Pollution Control Board m 1960 to regulate pollution from automobiles. 

Rollback Both linear rollback and modified rollback models were used by Barth to examine federal motor-vehicle goals for standards governing carbon monoxide, hydrocarbon, and oxides of nitrogen. The linear rollback principle was suggested and applied to these primary pollutants ... 

Barth, D. S. Federal motor vehicle emission goals for CO, HC, and NOx based on desired air quality levels. J. Air Pollut. Control Assoc. 20 519-523, 1970. 

Hamming, W. J., R. L. Chass, J. E. Dickinson, and W. G. MacBeth. Motor Vehicle Control and Air Quality The Path to Clean Air for Los Angeles. Paper 73-73 Presented at the 66th Annual Meeting of the Air Pollution Control Association, Chicago, Illinois, June 24-28, 1973. 19 pp. 

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