Liquefied natural gas (LNG) is the liquid form of the natural
gas people use in their homes for heating and cooking. There are about 113 active
LNG facilities in the united States. Most are used for storing natural gas for
wintertime use.
Technology for chilling and liquefying natural gas emerged
in the 1920s. Engineers could liquefy natural gas by cooling it to minus 260
degrees Fahrenheit. Liquefying natural gas allows for much more efficient storage.
In its liquid state, six hundred cubic feet of natural gas only takes up one
cubic foot of space, making it economical to transport between continents in
specially designed ocean tanker ships.
This LNG is then stored in insulated tanks, such as those
at Dominion Cove Point, where it can then be re-gasified and distributed to
customers by pipeline.
LNG provides a safe and efficient way of transporting
natural gas over long distances, particularly from gas producing nations
with insufficient pipeline infrastructures.
Dominion Cove Point will store LNG at about minus 260
degrees Fahrenheit at near atmospheric pressure in reinforced insulated
tanks.
The tanks consist of a stainless steel inner tank surrounded
by about four feet of insulation, which is contained by an outer steel
tank.
The storage tanks at Dominion Cove Point are built like huge thermos bottles
to keep the gas liquefied.
LNG Safety
LNG is non-toxic, odorless, non-explosive and non-flammable
in its liquid state. In fact, it will only burn after it has been re-gasified
and mixed in the proper proportion with air. Natural gas burns only within
the narrow range of a 5 to 15 percent gas-to-air mixture. Liquefied natural
gas has about 45 percent the density of water, so if spilled onto a waterway,
it will stay on top of the water until it evaporates into the atmosphere.
Since
commercial LNG transport began in 1959, LNG has been safely transported, stored
and delivered to densely populated cities in the United States, Europe and
Japan. During that time, more than 33,000 LNG carrier voyages, covering more
than 60 million miles, have arrived safely without a significant accident
or safety problem, either in port or on the high seas.
LNG ships are well-built, robust vessels with a double-hull
designed built to withstand the low-energy impacts common during harbor and
docking operations. They are a common sight throughout much of the world. Japan,
for example, receives 96 percent of its natural gas via LNG carriers.
