What is Natural Gas?
Natural gas is a mixture of hydrocarbons, predominantly methane (CH4). As delivered through the pipeline system, it also contains hydrocarbons such as ethane and propane and other gases such as nitrogen, helium, carbon dioxide, hydrogen sulfide, and water vapor. See the AFDC Fuel Properties database for more details.
Natural gas has a high octane rating and excellent properties for spark-ignited internal combustion engines. It is non-toxic, non-corrosive, and non-carcinogenic. It presents no threat to soil, surface water, or groundwater.
Most natural gas is extracted from gas and oil wells. Much smaller amounts are derived from supplemental sources such as synthetic gas, landfill gas and other biogas resources, and coal-derived gas.
Natural gas accounts for approximately one quarter of the energy used in the United States. Of this, about one third goes to residential and commercial uses, one third to industrial uses, and one third to electric power production. Only about one tenth of one percent is currently used for transportation fuel.