Did a little checking on gas for those, like me, that aren't too well versed in it.
(NG)
Natural Gas Formed by either decaying vegetation, microorganisms,and animals though some feel it is formed in the mantle of the earth and seeps up to become trapped in rock. Thus, they believe source is constantly regenerating. Composed mainly of methane along with ethane, propane, butane, etc. Natural gas is normally stripped of the heavier components and other matter to make it as pure as possible prior to using it for whatever purpose. NG used for household purposes is almost pure methane and as such is said to be "dry" natural gas whereas NG with other hydrocarbons present is said to be "wet".
(LNG)
Liquefied Natural Gas Natural gas that has been cooled to about -100F and highly condensed to liquify (without condensing cooling needs to be -260F). Used for transport and storage purposes(as liquid takes 1/600th the volume of gaseous NG). Can be converted back to NG when desired by raising the temperature. Energy density is 60% of diesel. Will only burn in mixtures with air of 5-15%. It will not explode in an unconfined environment. Thus, if there is an LNG spill, there is very little likelihood of it igniting an explosion.
(CNG)
Compressed Natural Gas Natural gas still in a gaseous state that is highly compressed. Can be sent via pipeline. Very safe. Used for transportation as much cleaner than other fuels such as gas, diesel, or propane. Usually at 2900-3200psi. Energy is 42% of LNG and 25% of diesel.
(LPG)
Liquefied Petroleum Gas - Mainly propane or butane or a mixture of both. Can be liquefied by pressure alone whereas LNG can only be liquefied by temperature. Partly a byproduct of petroleum refining. Used extensively worldwide for cooking, aerosol propellant, and refrigerant. Strong odor enhancer added as very flammable. Highest use in USA of all alternative fuels.
