Liquefied Natural Gas (LNG), whose main component is methane, is recognized as the cleanest fossil energy on earth. Colorless, odorless, non-toxic and non-corrosive, its volume is about 1/625 of the volume of the same volume of gaseous natural gas, and the mass of liquefied natural gas is only about 45% of the same volume of water.

The manufacturing process is to first purify the natural gas produced in the gas field, and then transport it by liquefied natural gas ship after a series of ultra-low temperature liquefaction. The burning of liquefied natural gas causes very little air pollution and releases a lot of heat, so liquefied natural gas is a relatively advanced energy source.

Liquefied natural gas is natural gas that becomes liquid after being compressed and cooled to its freezing point (-161.5°C). Usually, liquefied natural gas is stored in a low-temperature storage tank at -161.5°C and about 0.1MPa. Its main component is methane, which is transported by special ships or tank trucks and regasified when used. Since the 1970s, the world's LNG production and trade volume have increased rapidly.