FOSSIL FUELS
[1] Oil, natural gas, and coal were formed form the fossil remains of ancient plants or animals that accumulated in the earth. Over the centuries layer upon layer of these remains built up, and the tremendous weight of the layers compressed the organic material. Heat was generated, causing the carbon contained in the remains of plants and animals to be transformed into gas, oil, or coal.
[2] Crude oil is a major fuel source. It provides gasoline, diesel fuel, and kerosene for vehicles and jet planes. In industry oil may be burned to produce electricity and is the basis of petrochemicals, including plastics, polyester, and agricultural chemicals.
[3] Natural gas is composed of about 85 percent methane (CH4). In addition ethane, propane, heavier hydrocarbons, water, sulfur, helium, argon, and other rare gases may be present. Besides being used for heating homes, natural gas is used in industry to heat boilers and as the raw material for plastics and fertilizers. It is sometimes burned to supply elecrical power, especially as a supplement to other fuels.
[4] New technology is being used to obtain methane from rock formations. One successful technique, called massive hydraulic fracturing, pumps large volumes of fluid under pressure to create huge cracks in rock formations.
[5] There are several form of coal. Ranked according to heat value, these include lignite, sub-bituminous coal, bituminous or soft coal, and anthracite or hard coal. Half of the world’s supply of coal is bituminous. Used in making steel, coal is also widely used for firing industrial furnaces. In the United States coal supplies one-half of the nation’s electricity.
[6] A major disadvantage of coal is the air pollution that is causes. Particulates, radioactivity, gases, and sulfur are emitted into the atmosphere when coal is burned. The result is acid rain, a serious threat to health since it may contribute to bring diseases, including cancer.
[7] Modern technology is being applied to help eliminate the threat to health caused by air pollution from coal. Two processes used to reduce air pollutants are coal washing and fluidized bed combustion. By crushing it in water and allowing the impurities to sink, coal is, in effect, washed. In fluidized bed combustion, crushed coal is burned with crushed limestone to remove sulfur and inhibit the formation of nitogen oxide.
[8] A new process that is being used experimentally to make coal a more efficient energy producer is called magnetohydrodynamics. Coal is burned at very high temperatures to form gases with an electrical charge. Electricity is extracted in a magnetic field.
[9] In the United States fossil fuels supply 90 percent of the nation’s power. Will they be replaced in the near future by synthetic fuels? While nuclear and hydroelectric power currently supply 10 percent of electricity needs, experts feel that fossil fuels will cotinue to act as the principal fuel source as much as70 percent in the first quarter of the 21st century.
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