![Negishi LNG Terminal 01](https://upload.wikimedia.org/wikipedia/commons/c/cd/Negishi_LNG_Terminal_01.jpg)
A liquefied natural gas terminal is a facility for managing the import and/or export of
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 vol ...
(LNG). It comprises equipment for loading and unloading of LNG cargo to/from
ocean-going tankers, for transfer across the site, liquefaction, re-gasification, processing, storage, pumping, compression, and metering of LNG. LNG as a liquid is the most efficient way to transport natural gas over long distances, usually by sea.
Types
![Figure 1- LNG Export Facility (15404529106)](https://upload.wikimedia.org/wikipedia/commons/f/fd/Figure_1-_LNG_Export_Facility_%2815404529106%29.jpg)
Liquefied natural gas terminals can be classed as: liquefaction terminals for the export of LNG or
regasification terminals for the import of LNG. LNG terminals may combine both functions.
FSRU
![FSRU](https://upload.wikimedia.org/wikipedia/commons/9/9d/FSRU.jpg)
A floating storage and regasification unit (FSRU) is an LNG terminal whose main structure is a special ship moored near a port. As of January 2014 there are operating FSRUs in
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
,
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
,
Kuwait
Kuwait (; ar, الكويت ', or ), officially the State of Kuwait ( ar, دولة الكويت '), is a country in Western Asia. It is situated in the northern edge of Eastern Arabia at the tip of the Persian Gulf, bordering Iraq to the nort ...
,
Israel
Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...
, the
UAE
The United Arab Emirates (UAE; ar, اَلْإِمَارَات الْعَرَبِيَة الْمُتَحِدَة ), or simply the Emirates ( ar, الِْإمَارَات ), is a country in Western Asia (The Middle East). It is located at th ...
,
Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...
,
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
,
China,
Turkey
Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula in ...
and
Lithuania.
Terminal processes and equipment
Unloading and loading of LNG
Terminal facilities include
jetties
A jetty is a structure that projects from land out into water. A jetty may serve as a breakwater, as a walkway, or both; or, in pairs, as a means of constricting a channel. The term derives from the French word ', "thrown", signifying somet ...
and piers with articulated loading/unloading arms for transferring LNG between
ship
A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished ...
and shore. It also includes the piping used to transport LNG between the loading arms and the storage and processing facilities at the terminal. LNG is kept at about to maintain it in a liquid state. Conventional
carbon steels are brittle at this temperature. Therefore, special metals are used for this low-temperature cryogenic service where metal is in contact with LNG. Appropriate materials include
aluminium alloys
An aluminium alloy (or aluminum alloy; see spelling differences) is an alloy in which aluminium (Al) is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon, tin, nickel and zinc. There are two princip ...
with 3 to 5 percent magnesium and high nickel steels containing 9 per cent nickel. The loading/unloading arms and pipework are insulated to prevent heat gain from the air to minimise the vaporization of LNG. Tankers being loaded with LNG displace the vapour volume in their tanks, this gas is routed to boil-off or gas recovery storage tanks. Gas may then be compressed and fed into the local gas network, or it may be routed to the liquefaction plant and returned as liquid to the LNG storage tanks.
Pier
![MarmaraEreğlisiLNG_(24)](https://upload.wikimedia.org/wikipedia/commons/f/ff/MarmaraEre%C4%9FlisiLNG_%2824%29.jpg)
A LNG pier is a specialized kind of working
pier
Seaside pleasure pier in Brighton, England. The first seaside piers were built in England in the early 19th century.">England.html" ;"title="Brighton, England">Brighton, England. The first seaside piers were built in England in the early 19th ...
designed for the loading and offloading of liquefied natural gas to/from ships and shore based tanks.
A LNG pier could accommodate
LNG carriers of a range of sizes. They may be capable of handling LNG tankers of 70,000 to 217,000 cubic metres (m
3) cargo capacity (
Q-Flex
Q-Flex is a type of ship, specifically a membrane type liquefied natural gas carrier.
Technical description
Q-Flex vessels are propelled by two slow speed diesel engines, which are claimed to be more efficient and environmentally friendly than t ...
); or tankers of 125,000 to 266,000 m
3 cargo capacity (
Q-Max
Q-Max is a type of ship, specifically a membrane type LNG carrier. In the name Q-Max, "Q" stands for Qatar and "Max" for the maximum size of ship able to dock at the Liquefied natural gas (LNG) terminals in Qatar. Ships of this type are the large ...
). The pier would have at least two insulated lines, one for loading and/or unloading LNG and one for vapor supply or recovery as the vapor space above the LNG changes as the cargo is transferred. Ship-based or shore-based
cryogenic pumps are used to transfer the LNG to/from the
LNG storage tanks on shore.
Some of these piers are very long, up to , in order to reach to the depth of water required to accommodate LNG tanker traffic.
Storage of LNG
![LNG_terminal_Canvey_Island](https://upload.wikimedia.org/wikipedia/commons/c/c0/LNG_terminal_Canvey_Island.jpg)
The LNG flows through the pipelines that connect the loading arms on the jetty to storage tanks. Tanks are usually of double wall construction, with the inner tank constructed of low-temperature alloy. This is surrounded by insulation to reduce heat gain and an outer tank of conventional steel or
pre-stressed reinforced concrete. In-ground LNG tanks are also used; these are lined or unlined tanks beneath ground level. The low temperature of the LNG freezes the soil and provides effective containment. The tank is sealed with an aluminium alloy roof at ground level. Historically there have been problems with some unlined tanks with the escape of LNG into fissures, the gradual expansion of extent of the frozen ground, and ice heave which have limited the operational capability of in-ground tanks.
All piping connected to the LNG tanks, whether above ground or in-ground, are routed through the top of the vessel. This mitigates against loss of containment in the event of a piping breach. Tanks may be situated within a
bund wall to contain the LNG in the event of a rupture of the tank. This is usually a steel or concrete wall surrounding the tank to half the tank height.
Heat transfer into the tanks causes vaporisation of the LNG. This boil-off gas is routed to a boil-off gas holder. Gas may be returned to an unloading ship to make up the vapor space volume. Alternatively it may be compressed and fed into the local gas network, or it may be routed to the liquefaction plant and returned as liquid to the LNG storage tanks
Regasification
Regasification
Regasification is a process of converting liquefied natural gas (LNG) at −162 °C (−260 °F) temperature back to natural gas at atmospheric temperature. LNG gasification plants can be located on land as well as on floating barges, i.e. a Float ...
is the process of converting LNG from a liquid to a gaseous state. This requires significant quantities of heat energy to supply the
enthalpy of vaporization
The enthalpy of vaporization (symbol ), also known as the (latent) heat of vaporization or heat of evaporation, is the amount of energy (enthalpy) that must be added to a liquid substance to transform a quantity of that substance into a gas. T ...
of LNG and to heat it from -162 °C to about for introduction into a pipeline. Gas may be sent to a main gas transmission system, which typically operates at 70–100
bar. NGL is first pumped as liquid to this pressure. A series of
heat exchangers
A heat exchanger is a system used to transfer heat between a source and a working fluid. Heat exchangers are used in both cooling and heating processes. The fluids may be separated by a solid wall to prevent mixing or they may be in direct conta ...
are used to regasify the LNG. These may include submerged combustion vaporisers, or an intermediate fluid exchanger (using
propane or other fluids), or the use of
waste heat
Waste heat is heat that is produced by a machine, or other process that uses energy, as a byproduct of doing work. All such processes give off some waste heat as a fundamental result of the laws of thermodynamics. Waste heat has lower utility ...
from a nearby plant such as a power station. Final heating of the gas may use air or seawater heat exchangers.
To meet the quality specification of the gas transmission system, the outgoing gas may need to be analysed and enriched or diluted. Propane may be added to enrich the gas and
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
to ballast or dilute it.
Prior to distribution into a high-pressure transmission system, the regasified natural gas is metered and dosed with a stenching or
odorizing agent.
Liquefaction
At times of low demand, gas may be withdrawn from a transmission system and liquefied and stored. There are several proprietary systems that are used to liquefy natural gas and turn it into LNG. For full details of processes, see
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 vol ...
.
See also
*
List of LNG terminals
Liquefied natural gas ( LNG) is the liquefied form of natural gas, which has a much smaller volume than natural gas in its gaseous form. This liquefied condition is used to facilitate the carriage of natural gas over long distances, often by se ...
*
LNG carrier
An LNG carrier is a tank ship designed for transporting liquefied natural gas (LNG).
History
The first LNG carrier '' Methane Pioneer'' () carrying , classed by Bureau Veritas, left the Calcasieu River on the Louisiana Gulf coast on 25 January ...
*
LNG pier
A liquefied natural gas terminal is a facility for managing the import and/or export of liquefied natural gas (LNG). It comprises equipment for loading and unloading of LNG cargo to/from ocean-going tankers, for transfer across the site, liquefac ...
*
LNG storage tank
A liquefied natural gas storage tank or LNG storage tank is a specialized type of storage tank used for the storage of Liquefied Natural Gas. LNG storage tanks can be found in ground, above ground or in LNG carriers. The common characteristic of LN ...
References
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