Natural_Gas

[pic][pic][pic] | | Natural Gas Table of Contents How to Cite This Article Natural gas, a flammable gas within the Earth's crust, is a form of petroleum and is second only to crude oil in importance as a fuel. Natural gas consists mostly (88–95%) of the hydrocarbon methane (CH4), but proportions of hydrocarbons higher in the methane series are usually present, among them ethane (C2 H6), 3–8%; propane (C3 H8), 0.7–2%; butane (C4 H10), 0.2–0.7%; and pentane (C5 H12), 0.03–0.5%. Other gases present include carbon dioxide (CO2), 0.6–2.0%; nitrogen (N2), 0.3–3.0%; and helium (He), 0.01–0.5%. Carbon dioxide, nitrogen, and helium detract slightly from the heating value of natural gas. Helium and carbon dioxide, however, are valuable in their own right; in certain natural gases where their concentrations are relatively high, they may be extracted commercially. The hydrocarbons that make up natural gas are a component of in-ground petroleum. In the past the gas was considered a useless by-product of oil production and was burned off in the oil fields as waste. Coal beds also contain appreciable quantities of methane, the principal component of natural gas. Natural gas is produced on all continents except Antarctica. The world's largest supplier is Russia. The United States, Canada, and the Netherlands are also important sources. The most efficient, least costly means of transporting natural gas is via pipeline (see pipe and pipeline). The United States has nearly 3.2 million km (2 million mi) of natural-gas pipeline, much of it built during World War II. The Siberian–Western Europe gas pipeline, completed in 1983, was built to exploit the huge natural-gas reserves of the former USSR, primarily in present-day Russia. The gas may also be transported in pressurized tanks. Liquefied natural gas (LNG) must be kept under very high pressures and at very low temperatures during transport, but it requires far less space than the substance in its gaseous state. Uses Natural gas is used primarily as a fuel and as a raw material in manufacturing. It fuels home furnaces and water heaters, clothes dryers, and cooking stoves. It is used in brick, cement, and ceramic-tile kilns; in glassmaking; for generating steam in water boilers; and as a clean heat source for sterilizing instruments and processing foods. As a raw material in petrochemical manufacturing, its uses are widespread. They include the production of sulfur, carbon black, and ammonia. Ammonia is used as a source of nitrogen in a range of fertilizers and as a secondary feedstock for manufacturing such other chemicals as nitric acid and urea. Ethylene, perhaps the most important basic petrochemical produced from natural gas, is used in manufacturing plastics and many other products. Future Prospects Widespread concern about the environmental damage caused by the burning of coal and petroleum, and the realization that reserves of natural gas may be much greater than was once estimated, have spurred new technologies that have already increased its use significantly. Small gas-turbine generators add capacity to power-generation plants, and utilities anticipate lowered pollution as more natural gas replaces coal and oil. Because it is a clean-burning fuel that emits less carbon monoxide and carbon dioxide than gasoline, natural gas is already being used instead of gasoline in some U.S. truck, bus, and auto fleets. In 2002, total U.S. consumption of natural gas was 0.64 trillion m3, or 22.4 trillion ft3 (industrial consumption, 0.20 trillion m3, or 7.1 trillion ft3; electric power plants, 0.16 trillion m3, or 5.6 trillion ft3; residential, approximately 0.14 trillion m3, or 4.9 trillion ft3; commercial, 0.09 trillion m3, or 3.1 trillion ft3; other users, about 0.05 trillion m3, or 1.7 trillion ft3). In the United States, however, supplies have not kept up with demand, and the price of natural gas more than doubled between 1997 and 2003. Production at existing wells has diminished markedly, and conservation laws have prohibited exploration for new sources in many areas of the country. Abundant natural gas is available in Canada's Yukon Territory, but a pipeline to transport it to the United States was not projected to be ready until 2008. In 2002, only about 1% of the natural gas used in the United States was imported from overseas (in the form of LNG); at that time there were only four U.S. terminals suitable to handle the imported LNG. In coming years, growth rate in the use of natural gas will also occur in the Pacific region. Projections for a great increase in energy use in that region have spurred plans for the construction or completion of international pipelines running east and south from Russia and Kazakhstan, north from Australia and Indonesia, and west from Alaska. John W. Harbaugh Further Reading: Banks, Ferdinand, The Political Economy of Natural Gas (1987). Busby, R. L., ed., Natural Gas in Nontechnical Language (1999). Cannon, J. S., Paving the Way to Natural Gas Vehicles (1993). Davies, C. L., Industrial Utilization of Natural Gas (1988). Kennedy, J. L., Oil and Gas Pipeline Fundamentals, 2d ed. (1993). MacDonald, S. L., intro. by, The Role of Natural Gas in Environmental Policy (1993). Melvin, Alec, Natural Gas: Basic Science and Technology (1988). Top of Page How to cite this article: MLA (Modern Language Association) style: Harbaugh, John W. "Natural Gas." Grolier Multimedia Encyclopedia. Grolier Online, 2011. Web. 27 Apr. 2011. Chicago Manual of Style: Harbaugh, John W. "Natural Gas." Grolier Multimedia Encyclopedia. Grolier Online http://gme.grolier.com/article'assetid=0204850-0 (accessed April 27, 2011). APA (American Psychological Association) style: Harbaugh, J. W. (2011). Natural Gas. Grolier Multimedia Encyclopedia. Retrieved April 27, 2011, from Grolier Online http://gme.grolier.com/article'assetid=0204850-0