- Liquefied natural gas – more commonly referred to as LNG – is natural gas (primarily methane and ethane) which has been chilled to approximately -161ºC so that it becomes a liquid.
- Once the natural gas has been liquefied, it takes up much less space, occupying about 1/600 of the original space.
- In its liquefied form LNG won’t ignite, making it easier and safer to transport in cryogenic tanks aboard purpose-built vessels.
- LNG ships are equipped with sophisticated leak detection technology, emergency shutdown systems, advanced radar and positioning systems, and numerous other technologies designed to ensure the safe and secure transport of LNG.
Turning natural gas into LNG
The liquefaction of natural gas starts with the removal of any impurities such as dust, acid and helium. Water is removed to “dehydrate” the gas.
This “dry” natural gas is then condensed into a liquid at close to atmospheric pressure by cooling it to approximately -161ºC through a combination of heat exchange and pressure reduction with refrigerants.
Natural gas is generally converted into LNG using a range of coolant in one, two or three-stage processes.
The type of cooling process used depends on the specific needs of LNG plants with varying size, investment, location and output requirements.
When LNG reaches its destination, it is turned back into a gas at regasification plants. It is then piped to homes, businesses and industries where it fuels everything from gas stoves to power plants generating electricity.
LNG is also emerging as a cost-competitive and cleaner transport fuel, especially for shipping and heavy-duty road transport.
Natural gas, and LNG in particular, is expected to play an important role in meeting global demand for cleaner sources of energy. LNG trade increased from 100 million tonnes in 2000 to nearly 300 million tonnes in 2017. For comparison, only 80,000 tonnes of LNG was shipped by two carriers in 1964, the first year of the LNG trade.
Australia is one of the world’s leading suppliers of LNG and has multiple operating LNG projects which are creating employment opportunities and delivering a range of benefits to local economies.
Value of Australia’s LNG industry
According to IEA, the global natural gas market is expected to continue growing “at an annual rate of 1.6% and to pass the 44 trillion-cubic-metre mark by 2022. Liquefied natural gas is expected to account for 30% of that demand growth, with trading volume set to surpass 500 billion cubic metres (bcm) by 2023.”
In Australia, our export earnings increased 36% to $31.7 billion in 2017-2018 and, according to the Office of the Chief Economist, can expect earnings of $48.4 billion in 2018-19, thus eclipsing metallurgical coal as Australia’s second largest resources and energy export.