COAL FORMATION

Coal Formation

Introduction to Non-Renewable Resources :

Energy is the ability to do work. Energy is needed to power cars and factories, heat schools and homes, refine metals, and make many of the things we take for granted. Wind, water, the sun, nuclear reaction, coal, petroleum, natural gas, gasohol, the tides, and geothermal steam are some of Earth's energy resources. Some of these resources are renewable, others are nonrenewable. Several of the nonrenewable energy sources are being rapidly exhausted.

Fossil Fuels Coal Formation:

Coal forms in swampy areas as the result of the decay of plants in the absence of oxygen. Biochemical changes produced by bacteria release oxygen and hydrogen and concentrate carbon. Coal goes through several changes during formation. With increased pressure and time, impurities and moisture are removed. In swamps where coal forms, other sediment, such as sand, clay, and silt, also is deposited. The weight of the sediment compresses the underlying organic matter. During this process, moisture and other materials are squeezed out, leaving a high carbon concentration

The first stage in coal formation is material composed of about 75 to 90 percent water plus twigs, leaves, branches, and other plant debris. Although peat itself is not coal, it is an important fuel used in Ireland and the Soviet Union.

The second stage of coal formation is brown coal composed of compressed woody matter that has lost most of its moisture. It is used for local fuels in homes and industry. Germany uses its lignite to provide synthetic petroleum.

            The third stage of coal formation is a dense, dark, brittle material that has lost all its moisture and most other impurities. It is ignited easily by a flame. Although bituminous coal is an efficient heating material, it produces a smoky yellow flame, ash, and sulfur compounds when it is burned. Strict emission laws have limited the amount of pollutants industries can release when this coal is burned. Bituminous coal is mined throughout the United States with major fields in the Appalachians, the Great Plains, and the Colorado Plateau.

Anthracite, sometimes called "hard coal," is the final stage in coal formation. Lignite coal and bituminous coal are sedimentary rocks. Anthracite is a metamorphic rock. It is found only in areas of mountain building where heat and pressure were great. Anthracite is the cleanest of all coals with the least impurities because it is mostly carbon. It does not produce as much heat as bituminous coal, but it is preferred because it burns cleaner and longer. Anthracite fields occur in northeastern Pennsylvania, Great Britain, and parts of the Soviet Union.