LNG tanker

Liquefied natural gas (LNG) is natural gas which has been reduced to a liquid state by cooling it to minus 260°F. This LNG is stored in a double walled, insulated tank, which is specifically designed to prevent any gas from escaping and popularly known as a LNG Tanker. This tanker comes with a wall that surrounds it; this wall is capable of containing the entire volume of the tank in case spill takes place. One LNG tanker can transport enough LNG to equal 600 tankers carrying natural gas at atmospheric pressure and temperature. Once loaded on specially designed tankers, LNG is maintained in a liquid state by highly efficient insulation which surrounds the whole cargo compartment.

A small amount of LNG vaporization during the transition process is considered as normal, since natural gas liquefies at cryogenic temperatures, i.e. temperatures well below -100°C, there is always a continuous boil-off of the liquefied natural gas; another reason for the same is that no insulation system is perfect. The small amount of boil-off that occurs during storage is used as fuel or combined with the facility's daily send out. It can also be used to auto-refrigerate the remaining LNG and keeping it in its liquid state.

Upon arrival at the receiving facility, Liquefied Natural Gas is transferred into specially designed LNG storage tanks where it is stored as a liquid at near atmospheric pressure and minus 162°C of temperature. LNG is then pumped first to a double-walled storage tank, which is similar to those used in the liquefaction plant, at atmospheric pressure, then pumped at high pressure through various terminal components where it is warmed in a controlled environment to return it to a gaseous state for transportation by pipeline. This gas remains in storage until it is demanded for redelivery.

In case the the transportation takes place through the sea route, these LNG tankers are identified as LNG Ships. These ships are specially designed, have double hulls and are constructed of specialized materials that is capable of safely storing LNG at temperatures of -260° F/ -162.2° C. Ships unload LNG at specially designed terminals where the LNG is pumped from the ship to insulated storage tanks at the terminal. After conversion into gas at the terminal, pipelines or specifically designed trucks are used to deliver LNG to other storage facilities at various different locations.