Natural gas is frequently cooled for ease of transportation and storage. It must be cooled to at least –162°C (–260°F) when it becomes liquefied natural gas, or LNG. It is clear, odourless, non-toxic and non-corrosive. Liquefaction takes place when natural gas is cooled under high pressure, condensed and then reduced in pressure for storage. The resulting liquid is 1/600th of the volume of natural gas, and about half as dense as water.
There are a number of processes involved in LNG production: