What is Liquefied Natural gas (LNG)?
Liquefied Natural gas or LNG is the liquid form of natural gas cooled to its cryogenic temperature of −265°F (−160°C). During this process when gas is transformed into LNG, its volume reduced to 1/600th of its original volume. This huge reduction of volume is its main advantage, using this high reduction factor LNG can be transported over long distance economically.
Properties of LNG:
Liquefied natural Gas (LNG) is a clear liquid and its boiling point is –265 oF. Its specific gravity (SG) is 0.423, that means its lighter than water. So its floats on water like other hydrocarbon. Vapor of LNG is 1.52 times heavier than air, that means , during atmospheric dispersion its goes to water or ground surface. At ambient pressure and temperature Natural gas vapor is 0.54 times lighter than air . In case of LNG spill, its result evaporation and a visible vapor cloud is form. This LNG vapor is highly flammable in air if concentration is inbetween lower and upper explosive level. LNG vapor LEL is 5% and UEL is 15% . But if LNG spill on water it is more dangerous, it will result both spreading and evaporating simultaneously.Spreading pool of LNG is also capable of sustain a fire.
LNG vapor and air mixture does not potential for detonating in an open atmosphere. But a long transition distance and Significant confinement might result a detonation. Sometimes LNG impacting water is potential for producing a flameless explosion which is called RPT. If carbon steel comes in contact with LNG, they loose their strength and properties and become brittle.
At normal atmospheric pressure transport of LNG is safe, LNG is neither carcinogenic nor toxic, but its vapor is highly flammable.