Liquefied natural gas boils at approximately −162 °C at atmospheric pressure. Cooling natural gas to this cryogenic temperature condenses it into a liquid, reducing its volume dramatically for transport and storage.
LNG is primarily methane, although its exact composition varies with the source and processing. Before liquefaction, water, carbon dioxide, sulfur compounds, and other contaminants are removed because they could freeze or damage equipment. Specialized insulated tanks and ships keep the liquid cold.
When LNG warms, it vaporizes back into natural gas. This makes LNG useful for moving gas between regions that lack a pipeline connection, but it also means terminals require complex refrigeration, storage, and regasification systems. LNG is not the same product as LPG, which is stored mainly as propane and butane.