LNG is liquefied natural gas, a clear, colourless, non-toxic liquid that forms when natural gas is subjected to cooled condition to -1620C (-2600F). This process reduce the volume of the gas 600 times, therefore making it easier to store and transport e.g. by lorry tankers, ships to energy-hungry towns and cities overseas. Although, it can be very transported by pipe, but in some cases, pipeline construction may be too expensive or technically challenging. To solve this transportation problem, the natural gas liquefaction technique was developed so that liquefied natural gas (LNG) may be shipped by special tankers.
Natural gas is a fossil fuel derived from the slow transformation of plant and animal organic matter deposited on the seabed and other geologically suitable structures. Over the millennia, these materials were subjected to high temperatures and pressures, and converted by various processes:-
into gaseous hydrocarbons. Sometime the formation may yield both gas and solid hydrocarbon. They are available today in two forms: liquid (oil) and gaseous (natural gas).
Because oil and natural gas usually have a common origin, exploration and production are often conducted jointly in the same deposits. It consists of 90% methane (CH4), 5 to 10% ethane, and less than 1% other hydrocarbons such as butane and propane. It may also contain inert gases, including nitrogen and carbon dioxide, plus very small quantities of trace elements