Natural Gas

Natural gas was formed millions of years ago when most of the earth was covered by water. Plant and tiny animal remains were mixed and layered with sand and mud. When the Earth underwent natural but drastic changes to form today’s landscape, the intense heat and pressure transformed these fossils into hydrocarbons—chemical compounds of hydrogen and carbon atoms. Natural gas is made up mainly of a chemical called methane, a simple, compound that has a carbon atom surrounded by four hydrogen atoms. Methane is highly flammable and burns almost completely. There is no ash and very little air pollution. Depending on the arrangement of the atoms, what were once sea plants and animals are now natural gas or crude oil deposits contained in the earth’s crust. Natural gas (a combustible, gaseous mixture of simple hydrocarbons) is a very light portion of petroleum, which includes both natural gas and crude oil. Natural gas may rise to the surface through natural openings in the earth’s crust or can be brought to the surface through man-made wells. Humans discovered thousands of years ago that this naturally occurring resource could be burned and used for heat and light.

In its natural state you can’t see or smell natural gas. It is colorless, odorless and lighter than air. Mercaptan, a chemical odorant, is added to natural gas so it can be smelled if it leaks. 

Natural gas is made up mostly of methane, which has a simple hydrocarbon structure of one carbon atom and four hydrogen atoms (CH4). This means it burns easily and emits less pollution. When natural gas is burned, it produces mostly carbon dioxide and water vapor.

Approximately 23 percent of the energy consumption of the U.S. comes from natural gas. Over one-half of the homes in the U.S. use natural gas as their main heating fuel.

Natural gas can be found in a variety of different underground formations, including: shale formations, sandstone beds, coal seams, and deep, salt water aquifers (underground ponds of water).

Natural gas is moved by pipelines from the producing fields to consumers. Since natural gas demand is greater in the winter, gas is stored along the way in large underground storage systems, such as old oil and gas wells or caverns formed in old salt beds. The gas remains there until it is added back into the pipeline when people begin to use more gas, such as in the winter to heat homes. When chilled to very cold temperatures, approximately -260 degrees Fahrenheit, natural gas changes into a liquid and can be stored in this form. Liquefied natural gas (LNG) can be loaded onto tankers (large ships with several domed tanks) and moved across the ocean to deliver gas to other countries. Once in this form, it takes up only 1/600th of the space that it would in its gaseous state. When this LNG is received in the United States, it can be shipped by truck to be held in large chilled tanks close to users or turned back into gas to add to pipelines.

U.S. Natural Gas Pipeline Network

Natural Gas Facts

• Over one million miles of gas pipelines serve the United States
• Natural gas is the cleanest-burning fossil fuel
• Natural gas use has increased by 35 percent over the past ten years, and is projected to grow 45 percent by 2015.
• Ninety-nine percent of the natural gas used in the United States comes from North America.
• The U.S. gas distribution network is comprised of more than 1.2 miles of pipeline, supplying 175 million consumers.
• Natural gas provides 24 percent of all the energy used in the United States.
• About 55 percent of American homes use natural gas for heating.
• The first use of gas energy in the United States occurred in 1816, when gaslights illuminated the streets of Baltimore, Maryland.

World Natural Gas Reserves by Country 

source:CIA Factbook

For More Information About Fossil Fuels Click On The Links Below

• Fossil Fuels

• Coal

• Oil 

• Gasoline

credit: Energy Information Administration, U.S. Department of Energy, World Coal institute, OPEC, Shell Oil company