Literature Survey of LNGLNG is abbreviation of Liquefied Natural Gas. Introduced so as to increase fuel carrying capacity and reduce air pollution. This helps in travelling long distances without refueling and hence useful for large heavy vehicles. The LNG is nothing but natural gas comprising predominantly of Methane, but it is stored as a fuel in liquefied form, which can also be termed as cryogenic form. In order to liquefy the fuel the temperature of the gas is reduces which causes the natural gas to be converted into the liquid state.CNG (Compressed Natural Gas) is also comprised of natural gas but here instead of reducing the temperature the gas is compressed, and stored as a fuel, at room temperature. Here there is no change of physical state of the gas.