Natural gas is a mixture of various hydrocarbons, with the main component being methane. There are large reserves of natural gas in US, but it can also be obtained as a byproduct from landfill operations. Natural gas is being used extensively as an alternate fuel for vehicles in place of gasoline and diesel.
Natural gas can be used as compressed gas (CNG) or as liquefied gas (LNG). CNG is used for small and medium sized vehicles as an alternative to gasoline while LNG is used in heavy vehicles using diesel as fuel. At CNG fueling stations natural gas is compressed in the compressors. At LNG stations the liquefaction of natural gas is carried out at temperatures below 260 Fahrenheit.
Vehicles running on natural gas are called natural gas vehicles (NGV). A large number of NGVs are already running in US, with the largest number in California, followed by, Texas, New York, Oklahoma and Arizona.