liquefied natural gas Liquefied natural gas (LNG) is natural gas (predominantly methane, CH4, with some mixture of ethane, C2H6) that has been cooled down to liquid form for ease and safety of non-pressurized storage or transport. It takes up about 1/600th the v ...

(LNG) spill can happen during an accident or an intentional act. LNG is normally stored and transported in liquid form at a temperature of approximately . If this cooled liquid is released from a storage facility, pipeline, or LNG transport ship, then it begins to warm. As LNG warms above its storage temperature, the liquid begins to vaporize. The resulting gas produced by this warming is typically

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Ear ...

, which is the major component (with some

ethane Ethane ( , ) is an organic chemical compound with chemical formula . At standard temperature and pressure, ethane is a colorless, odorless gas. Like many hydrocarbons, ethane is isolated on an industrial scale from natural gas and as a petro ...

) of

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon ...

and one of the most potent and hazardous

greenhouse gas A greenhouse gas (GHG or GhG) is a gas that absorbs and emits radiant energy within the thermal infrared range, causing the greenhouse effect. The primary greenhouse gases in Earth's atmosphere are water vapor (), carbon dioxide (), met ...

es. If a spill occurs and the vapor does not ignite, it would build to higher concentrations. At higher concentrations, the vaporized methane will cause an

asphyxiation Asphyxia or asphyxiation is a condition of deficient supply of oxygen to the body which arises from abnormal breathing. Asphyxia causes generalized hypoxia, which affects primarily the tissues and organs. There are many circumstances that can ...

hazard to anyone exposed. If a spill or leak followed by a vaporization event were to occur in or near water, then water in contact with the spilled LNG can accelerate the vaporization process and increase the concentration of vapor in the immediate area. According to the 2004 Sandia report, this is of special concern to ship and pilot-boat crews, emergency response personnel or others who are exposed in a marine environment. An ignition source close to the origin of the spill is likely to cause ignition and result in rapid burn off of natural gas vapors, rather than an explosion. No cargo explosions have ever been reported.

Footnotes

{{reflist Liquefied natural gas