Liquefied Natural Gas (LNG)


Natural gas when cooled to its liquid state is called Liquefied Natural Gas (LNG). This process is carried out at a liquefaction facility, where LNG is formed at minus 162 degrees Celsius at atmospheric pressure. LNG is a cleaner alternative with a lower carbon footprint compared to traditional fossil fuels. LNG is easier to produce than other fossil fuels. Like CNG, LNG can also be used as an automotive fuel. Long-haul vehicles such as trucks and buses benefit from the longer range offered by LNG owing to its comparatively greater energy density per volume. LNG is more affordable than diesel or petrol.

LNG Terminals

Natural gas arrives at LNG terminals as super-cooled LNG, which is then warmed up in regasification units located at the terminal to regenerate natural gas in its gaseous form. This regassified LNG (RLNG) is then supplied through pipelines spanning across the country. Alternatively, LNG can also be delivered using LNG trucks.

India has LNG terminals at Dahej, Hazira and Mundra in Gujarat, Dhabol in Maharashtra, Kochi in Kerala and Ennore in Tamil Nadu.

Petronet LNG Limited (PLL), a joint venture company of Bharat Petroleum, IOCL, ONGC and GAIL, has two LPG import terminals – at Dahej and Kochi.

Bulk Supply to Industries

Bulk sale of natural gas and LNG to industries involve transporting it in pipelines from LNG import terminals as well as inland production sites. Industries such as fertilizer units are among the bulk users of natural gas, who are supplied Piped Natural Gas (PNG) through cross-country gas pipelines and branch pipelines.
In parallel, expansion of City Gas Distribution (CGD) networks to deliver PNG to households and CNG for vehicles across the country is another prominent aspect of the mega push to increase the use of natural gas in the economy.  

LNG Storage and Transportation

Natural gas in the form of LNG offers remarkable flexibility in storage and transportation. On land, natural gas is conveniently delivered to consumption centers in its gaseous form through pipelines. But if pipeline transportation is not an option available, natural gas is converted and stored as Liquefied Natural Gas (LNG) at minus 162 degrees Celsius, by cooling it down using a refrigeration cycle. At this super-cool temperature, natural gas turns into its liquid form. The resulting LNG occupies only 1/600th of its original gaseous volume and is thus transported efficiently in large specialized tanker ships that have the requisite onboard cryogenic storage facilities (thermally insulated tanks) to keep LNG in liquid form.

Upon arrival at an LNG import terminal, LNG is regassified by heating it to convert it back into its gaseous form, which is called R-LNG (regassified LNG). This natural gas regenerated from LNG is transported swiftly via pipeline networks stretching thousands of kilometers. LNG can also be delivered employing LNG trucks with double-walled insulated cryogenic tanks to store LNG at ultra-low temperatures.

Similarly, on-ground LNG storage tanks are specially designed cryogenic tanks that maintain frigid conditions to keep LNG in the liquid state. These tank systems are specially engineered to use auto-refrigeration to keep the pressure and the temperature in the tank constant.

India’s LNG Imports (2012 to 2021)

flow gas

Source: Indian Petroleum & Natural Gas Statistics, MOPNG (2020-21)

Many nations have come to rely on LNG for a significant portion of their energy needs. China is the largest Importer of LNG in the world. China, Japan, South Korea, Taiwan and India are respectively the top five importers of LNG (2021 data).

To view Details of LNG terminals, click here