Energy Sources of Fuel

A fuel is typically a substance that burns in order to release energy. Common chemical fuels include petroleum, coal and natural gas. Nuclear fuels are fissile materials consumed in a nuclear reactor. In the U.S. Energy Information Administration's 2009 Annual Energy Review, petroleum accounted for 37 percent of the nation's energy use. Natural gas was 25 percent, coal use was 21 percent, nuclear electric power was 9 percent and renewable energy sources were 8 percent.

Oil

Crude oil is a yellow-to-black liquid fuel source typically found in underground pools called reservoirs. Another name for crude oil is petroleum. Engineers get rock samples from the earth to discover if a chosen area has significant oil deposits. If a site contains acceptable petroleum amounts, drilling begins. Above the drilling hole, a derrick is constructed to contain the tools and pipes entering the well, and then oil is extracted.

Coal

Coal is a black or brownish-black rock composed mostly of carbon and hydrocarbons. In the United States, burning coal supplies more than half the electricity consumed by Americans. Four main types of coal exist. Anthracite contains 86 to 97 percent carbon, and is less than one-half percent of coal mined in the U.S. Bituminous coal contains 45 to 86 percent carbon, about half of U.S. coal production. Sub-bituminous coal is 35 to 45 percent carbon. About 46 percent of the coal produced is sub-bituminous. Lignite contains 25 to 35 percent carbon, and accounts for about 7 percent of U.S. coal.

Natural Gas

Methane is the main ingredient of natural gas. Geologists look for areas that could contain gas deposits. Drills extract the gas from the ground, and it flows through the well into large pipelines. Butane and propane gases are byproducts of methane gas extraction, and have useful commercial applications. When chilled to about minus 260 degrees Fahrenheit, natural gas changes into a liquid and stores in this form. The liquid form is easier to transport, because it requires much less space.

Nuclear Power

The nuclear fuel cycle includes industrial processes that produce electricity from uranium in nuclear power reactors. Uranium is a relatively common element found throughout the world. After mining, it must be processed before use in a nuclear reactor. Excavation techniques include underground and open pit mining. Reactor fuel typically consists of ceramic pellets formed by pressing uranium oxide and baking it at very high temperatures. The pellets insert into metal tubes to form fuel rods, which are attached to the fuel assembly for reactor use.

References

• U.S. Energy Information Administration: What are the Major Sources and Users of Energy in the United States?
• U.S. Energy Information Administration: Oil (Petroleum) Basics
• U.S. Energy Information Administration: Coal Basics
• U.S. Department of Energy: Coal
• U.S. Energy Information Administration: Natural Gas Basics
• World Nuclear Association: The Nuclear Fuel Cycle