An LNG train is the term used to describe the liquefaction and purification facilities in a liquefied natural gas plant.
In order to make it practical and commercially viable to transport natural gas from one country to another, its volume has to be greatly reduced. To obtain maximum volume reduction, the gas has to be liquefied through the application of refrigeration technology which makes it possible to cool the gas down to approximately -160 °C. This process also requires very strict safety measures and precautions during all liquefaction stages, due to the highly vulnerable and flammable nature of the gas involved.
Since the numerous impurities that are naturally found in the raw gas freeze at low temperatures, and would thus block the cryogenic section of the plant, the gas has to be purified before it can be cooled down to cryogenic temperatures.[1]
Each LNG plant consists of one or more trains to compress natural gas into liquefied natural gas. A typical train consists of a compression area, propane condenser area, methane, and ethane areas.[2][3]