Readily combustible sedimentary rock that is black or brownish-black in color; coal is found in rock strata and in form of layers that are called coal beds. Harder forms of the rock such as the anthracite coal are regarded as metamorphic rock due to exposure to elevated levels of temperature as well as pressures.
Composition of Coal
Coal is usually made of the following components -
• Carbon;
• Sulfur;
• Oxygen;
• Nitrogen; and
• Hydrogen.
Evolution of Coal
Beginning as layers of plant matter that accumulates at the bottom of water, remaining protected from biodegradation as well as oxidization, they continue to form into coal. One of the locations providing ideal climate for such carboniferous periods is the wide shallow seas. Deeply buried sediments ground in immense peat bogs those were covered over and deeply buried and metamorphosed into coal. With passage of time, the chemical as well as the physical properties of the plant remains are changed to form the solid material. This solid material is coal.
Features of Coal
• Coal is one type of fossil fuel;
• It is the largest source of energy for electricity generation throughout the world;
• It is also one of the largest anthropogenic sources of emission of carbon dioxide;
• Carbon die oxide emissions from coal is higher than emissions in petroleum;
• Coal is mined from underground or open crust pits.
Use of Coal for Electricity Generation
Primarily used as solid fuel for production of electricity as well as heat through the process of combustion, consumption of coal was around 7,280,000,000 by 2010. China is the largest producer of coal followed by India. Maximum usage of coal was in United States for electricity generation where 90% of the coal produced or imported was used for the purpose.
Pulverization and Combustion of Coal
For generation of electricity and heat, coal is pulverized and combusted either in a furnace or with a boiler. Furnace heat converts boiler water into steam that is used to spin turbines turning generators creating electricity. Over the years the thermo dynamic efficiency of the process has increased a lot.
While scientists are trying to find out divergent alternative sources for power, till date coal continues to be the major source of energy on the planet earth.
About this Author
People desirous of learning more about coal uses can benefit by visiting science.jrank.org. Besides various uses, the site also offers information in detail about different aspects of use of the sedimentary rock as source of energy generation.
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