LNG Regasification

An LNG regasification terminal converts liquefied natural gas back into gaseous form so it can enter a pipeline. LNG, stored at about -162°C near atmospheric pressure, is pumped, heated in vaporizers, checked for quality and delivered at the required pipeline pressure; regasification is primarily a physical phase change.

From ship to vaporizer

Regasification follows a controlled sequence from cryogenic unloading to high-pressure gas delivery.

• LNG is unloaded through insulated arms or hoses and kept in cryogenic storage tanks, which limit heat entry and safely contain the liquid.
• Low-pressure pumps move LNG out of storage, after which send-out pumps raise its pressure before vaporization.
• Vaporizers transfer heat from seawater, ambient air, or a fuel-fired system. The LNG boils and becomes gaseous without combustion or chemical conversion.
• Heating the liquid after pressurization reduces the energy otherwise required to compress the same quantity as a gas.

Making the gas pipeline-ready

The vaporized gas must match the receiving pipeline's operating and quality requirements before custody transfer.

• Outlet equipment controls the gas's pressure, temperature and flow rate so that it can safely enter the connected pipeline.
• Gas quality is monitored for parameters such as composition, calorific value, water content, sulphur compounds and hydrocarbon dew point.
• Conditioning or blending may be used where necessary, followed by metering for commercial measurement. Odorant may be added if required by the receiving distribution system.

Handling boil-off gas and risks

Some LNG continuously evaporates because small amounts of heat enter during storage and unloading. This boil-off gas is recovered through compression, recondensation, use as terminal fuel, or controlled routing within the gas system.

• Emergency shutdown systems isolate unloading and processing equipment when unsafe conditions arise.
• Gas and fire detection, spill containment, pressure relief and separation distances address LNG's cryogenic and flammability hazards.