Liquefied natural gas

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

The manufacturing process is to purify the natural gas produced in the field first, and after a series of ultra-low temperature liquefaction, the use of liquefied natural gas ships. Liquefied natural gas combustion after the air pollution is very small, and the release of heat is large, so liquefied natural gas is a relatively advanced energy.

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

In 2021, China imported 81.4 million tons of LNG, overtaking Japan to become the world's largest importer of liquefied natural gas (LNG), marking the first time since the early 1970s that China has become the world's largest LNG importer, with Japan slipping into second place. The world's largest LNG supplier is Australia, with 83 million tons. Qatar followed with 81.3 million tons of LNG. The United States ranked third with 73.6 million tons of LNG. 

In 2022, Qatar became the world's largest LNG exporter with 80 million tons of LNG exports

About:

Natural gas refers to flammable gas stored in the formation, mainly a mixture of low molecular alkane, can be divided into dry gas and wet natural gas two, dry gas composition is mainly methane, wet natural gas in addition to containing a lot of methane, but also contains more ethane, propane and butane.

The main components of Liquefied Natural Gas (Liquefied Natural Gas) are methane, with small amounts of ethane and propane. Liquefied natural gas is colorless, tasteless, non-toxic, non-corrosive, natural gas can be liquefied at atmospheric pressure and about -162 ° C, and the volume of liquefied natural gas is about 1/625 of the gaseous volume.

At atmospheric pressure, the density of LNG is about 430-470kg/m³ (slightly different depending on the composition), the ignition point is about 650℃, the caloric value is 52MMBtu (1MMBtu=2.52×108cal), and the explosion limit (volume) in the air is 5%-15%. The storage of liquefied natural gas is one of the natural gas storage methods. LNG storage tank is usually a double-layer metal tank, and the inner material in contact with LNG is 9%Ni low-temperature steel, the outer material is carbon steel, the middle insulation layer is expanded perlite, and the bottom insulation layer is foam glass.

In 2022, Qatar became the world's largest LNG exporter with 80 million tons of LNG exports, and global LNG exports reached 399 million tons, an increase of 5% .

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The world's advanced countries in environmental protection are promoting the use of LNG. In addition to being used as fuel for power plants, factories and household users, the methane contained in it can be used as chemical raw materials such as fertilizer, methanol solvent and synthetic acetic acid. In addition, the ethane and propane contained in it can be cracked to produce ethylene and propylene, which is an important raw material for plastic products.

In addition, ultra-low temperature LNG can provide a large amount of cold energy during the process of transforming into a normal temperature gas at atmospheric pressure, which can be recovered and used for six low temperature purposes: Make air separation to produce liquid oxygen, liquid nitrogen, liquefied carbon dioxide, dry ice manufacturing, the use of cold energy for power generation, the manufacture of frozen food or used in frozen warehouses, rubber, plastic, iron filings and other industrial waste low temperature crushing treatment, seawater desalination.

In the face of the increasingly serious ecological environmental pollution situation, in order to optimize the energy consumption structure, improve the atmospheric environment, and achieve sustainable economic development strategy, people choose natural gas as a clean, efficient ecological high-quality energy and fuel. Both industry and civil use are increasingly dependent on natural gas. Liquefied natural gas (LNG) is the liquid form of natural gas, and in some cases, choosing LNG has more advantages than choosing gaseous natural gas. The application of LNG is actually the application of natural gas, but due to its characteristics, LNG is more widely used than natural gas .

Industrial LNG

1. Power generation

The use of LNG is efficient and economical. In power generation, the thermal energy utilization rate of natural gas can reach 55%, which is higher than that of fuel oil and coal. Especially for peaking power plants, the advantage of natural gas replacing fuel oil is very obvious. Power generation is the most important industrial use of LNG.