What is Liquefied Gas?

• Liquefied natural gas (LNG) is natural gas that is stored and transported in liquid form at atmospheric pressure at a temperature of –260 o F. Like the natural gas that is delivered by pipeline into homes and businesses, it mainly consists of methane (CH 4 ).
• Liquefying natural gas provides a means of moving it long distances when pipeline transport is not feasible.
• Natural gas is turned into a liquid using a refrigeration process in a liquefaction plant. The unit where LNG is produced is called a train. Liquefying natural gas reduces its volume by a factor of 610. The reduction in volume makes the gas practical to transport and store.
• Generally, LNG is measured in metric tons when it is a liquid, and in cubic feet when it is in its gaseous state.¹
• In international trade, LNG is transported in specially built tanks in double-hulled ships to a receiving terminal where it is stored in heavily insulated tanks. The LNG is then sent to regasifiers which turn the liquid back into a gas that enters the pipeline system for distribution to customers as part of their natural gas supply.
• On a smaller scale, LNG may also be produced by liquefying gas taken from a pipeline, storing it, and then regasifying it for pipeline distribution to customers when demand is high, such as on cold winter days. These small regasification plants are often called “peakshaving plants.” Alternatively, the LNG may be transported in special tanker trucks to small facilities where it is stored and regasified as needed. Such facilities are called “satellite plants.” The United States has about 100 LNG satellite and peakshaving plants throughout the country.
• As a part of safety engineering, all LNG facilities are designed to prevent fires and contain the LNG in the event of a spill. In the United States, these facilities must conform to standards set by the United States Department of Transportation, the United States Coast Guard, the Federal Energy Regulatory Commission, the National Fire Protection Association, State utility commissions, port authorities, and other local agencies.