What is LNG?

In the UK, natural gas is transported to homes and industry through the National Transmission System. The gas cooled to form LNG (liquefied natural gas) is the same as the natural gas used in our homes

LNG is natural gas that has been cooled down to approximately -160ºC to become a liquid, reducing its volume by 600 to 1. By reducing the volume, it becomes viable to transport LNG over long distances via carrier ships.

It is not possible to liquefy methane solely by pressurising it so LNG is kept liquid at minus 160 degrees Celsius but at atmospheric pressure.

LNG consists almost entirely of methane and is odourless, colourless, non-corrosive and non-toxic.

If LNG is exposed to air, the temperature of the liquid will stay at approximately -160oC.  However, at its surface, the LNG will evaporate into natural gas vapour (methane) which is lighter than air. This vapour is easily dispersed, making ignition unlikely.

• Natural gas is only flammable when mixed with air in concentrations between 5 and 15%
• Natural gas is composed primarily of methane (typically, at least 90%).
• Natural gas is a very clean form of energy and is nature’s simplest and most abundant hydrocarbon fuel.

Liquid petroleum gas (LPG) is often confused with LNG (liquefied natural gas) and vice versa.

LPG is composed primarily of propane (upwards to 95%) and smaller quantities of butane, and is used primarily for residential and commercial applications. LPG is maintained as a liquid by means of elevated pressure. It is heavier than air in its vapour state and has a wider flammability range. 

LPG is kept liquid by confining it under high pressure. Whereas LNG is stored at a very low temperature but at atmospheric pressure. These distinct qualities require use of entirely different material properties, thicknesses, insulating materials and standards for containment.

For Frequently Asked Questions, click here