What is LNG?

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Natural gas is transported on specially designed ships as liquefied natural gas (LNG). LNG is natural gas that is cooled to -260° Fahrenheit, the temperature at which natural gas becomes a liquid. The volume of the liquid is 600 times smaller than the gaseous form.
An ocean-going LNG carrier
A photograph of an ocean-going ship transporting liquefied natural gas (LNG)

Source: Stock photo (copyrighted)

Liquefied natural gas (LNG) is natural gas that has been cooled to a liquid state, at about -260° Fahrenheit, for shipping and storage. The volume of natural gas in its liquid state is about 600 times smaller than its volume in its gaseous state. This process, which was developed in the 19th century, makes it possible to transport natural gas to places pipelines do not reach and to use natural gas as a transportation fuel.

LNG increases markets for natural gas

Where natural gas pipelines are not feasible or do not exist, liquefying natural gas is a way to move natural gas from producing regions to markets, such as to and from the United States and countries in Asia or Europe. Asian countries combined account for the largest share of global LNG imports.

LNG is shipped in special ocean-going ships (tankers) between export terminals, where natural gas is liquefied, and import terminals, where LNG is returned to its gaseous state or regasified. From an import terminal, regasified LNG is transported by natural gas pipelines to gas-fired power plants, industrial facilities, and residential and commercial customers.

Most LNG is transported by large ships/tankers called LNG carriers in onboard, super-cooled (cryogenic) tanks. LNG is also transported in relatively small volumes on ships using International Organization for Standardization (ISO)-compliant containers and on trucks. At import facilities, LNG is typically stored onsite in special cryogenic storage tanks before regasification and input into pipelines that transport regasified LNG to consumers.

In the United States, some power plants store natural gas onsite as LNG to generate electricity when electricity demand is high, such as during cold and hot weather, or when pipeline delivery capacity is constrained or insufficient to meet increased demand for natural gas by other consumers. The power plants take natural gas from natural gas pipelines, liquefy it in small-scale liquefaction facilities, and store it in cryogenic tanks. The LNG is regasified and burned by the power plants when needed. Some ships, trucks, and buses, with specially designed LNG tanks, use LNG as fuel.

The United States imports and exports LNG

In recent years, the United States has become a net exporter of LNG, largely because of increasing U.S. natural gas production; declining natural gas imports by pipeline, primarily from Canada; declining LNG imports; and expansion of LNG-export terminal capacity.

The United States imported very small amounts of LNG until 1995, and then LNG imports generally increased each year until peaking in 2007 at about 771 billion cubic feet (Bcf). Increases in U.S. natural gas production and expansion of the natural gas pipeline network have reduced the need to import natural gas. LNG imports declined in most years since 2007.

In 2018, the United States imported about 76.5 Bcf of LNG—the lowest amount since 1997—from five countries. The source countries, amounts, and percent shares of total LNG imports in 2018 were

  • Trinidad and Tobago—65.8 Bcf—86%
  • United Kingdom—3.1 Bcf—4%
  • Nigeria—2.9 Bfc—4%
  • France—2.8 Bcf—4%
  • Canada—1.9 Bcf—2%
  • The Everett regasification terminal near Boston, Massachusetts, receives most U.S. LNG imports. Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont may have significant pipeline constraints when heating demand increases substantially during periods of very cold weather. LNG imports help to meet natural gas demand in New England because the region currently has limited pipeline interconnections with the Northeast and U.S. natural gas producing regions.

    In 2018, U.S. LNG exports reached a record high of about 1,083 Bcf to 37 countries. The top five destination countries, amounts exported, and percent shares of total U.S. LNG exports in 2018 were

    • South Korea—252.2 Bcf—23%
    • Mexico—182.8 Bcf—17%
    • Japan—125.5 Bcf—12%
    • China—90.5 Bcf—8%
    • India—57.6 Bcf—5%
    • In 2018, LNG carriers transported nearly all U.S. LNG exports. Less than 1 Bcf of U.S. LNG exports went to Barbados and the Bahamas on small tankers equipped with ISO containers. About 0.6 Bcf of U.S. LNG exports were by truck to Canada and Mexico, with 97% going to Mexico.

      Sometimes, when natural gas prices are favorable to do so, the United States re-exports some of the LNG that it originally imported. However, the United States did not re-export LNG in 2018.

      U.S. LNG exports are expected to increase in coming years as new U.S. LNG export capacity comes online. Detailed information is available on existing and under-construction large-scale U.S. liquefaction facilities in the United States.