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Home > Energy Resources > Natural Gas > What is it?
What is natural gas? 
 
Natural gas, in itself, might be considered an uninteresting gas - it is colorless, shapeless, and odorless in its pure form. Quite uninteresting - except that natural gas is combustible, abundant in the United States and when burned it gives off a great deal of energy and few emissions. Unlike other fossil fuels, natural gas is clean burning and emits lower levels of potentially harmful byproducts into the air. We require energy constantly, to heat our homes, cook our food, and generate our electricity. It is this need for energy that has elevated natural gas to such a level of importance in our society, and in our lives.
 
A Methane molecule, CH4 
 Source: USGS
 
Natural Gas Constituents 

Natural gas is a combustible mixture of hydrocarbon gases. While natural gas is formed primarily of methane, it can also include ethane, propane, butane and pentane. The composition of natural gas can vary widely, but below is a chart outlining the typical makeup of natural gas before it is refined.

Typical Composition of Natural Gas
Methane CH4 70-90%
Ethane C2H6 0-20%
Propane C3H8
Butane C4H10
Carbon Dioxide CO2 0-8%
Oxygen O2 0-0.2%
Nitrogen N2 0-5%
Hydrogen sulphide H2S 0-5%
Rare gases A, He, Ne, Xe trace

In its purest form, such as the natural gas that is delivered to your home, it is almost pure methane. Methane is a molecule made up of one carbon atom and four hydrogen atoms, and is referred to as CH4.  The distinctive smell that we often associate with natural gas is actually an odorant called mercaptan that is added to the gas before it is delivered to the end-user.  Mercaptan aids in detecting any leaks. 

Source:  NaturalGas.org

Last Updated: 3/21/2011 2:54 PM 
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