The Basics of LNG

LNG is the abbreviation of English Liquefied Natural Gas, that is, liquefied natural gas. It is the product of cooling and liquefaction of natural gas (methane CH4) after purification and ultra-low temperature (-162°C, one atmospheric pressure). The volume of liquefied natural gas is greatly reduced, about 1/600 of the volume of natural gas at 0°C and 1 atmosphere pressure, that is to say, 600 cubic meters of natural gas can be obtained after 1 cubic meter of LNG is gasified.

Liquefied natural gas is colorless and odorless, the main component is methane, there are few other impurities, it is a very clean energy. Its liquid density is about 426kg/m3, and the gas density is about 1.5 kg/m3. The explosion limit is 5%-15% (volume%), and the ignition point is about 450 °C. The natural gas produced by the oil/gas field is formed by removing liquid, acid, drying, fractional distillation and low temperature condensation, and the volume is reduced to 1/600 of the original.

With the vigorous development of my country’s “West-East Gas Pipeline” project, the national heat of natural gas utilization has been set off. As the best energy source in the world, natural gas has been highly valued in the selection of urban gas sources in my country, and vigorous promotion of natural gas has become my country’s energy policy. However, due to the large scale, high investment and long construction period of natural gas long-distance pipeline transportation, it is difficult for long-distance pipelines to reach most cities in a short period of time.

Using high pressure, the volume of natural gas is reduced by about 250 times (CNG) for transportation, and then the method of depressurizing it solves the problem of natural gas sources in some cities. The application of ultra-low temperature refrigeration technology to make natural gas into a liquid state (about 600 times smaller in volume), using ultra-low temperature cold storage tanks, transporting natural gas over long distances by vehicles, trains, ships, etc., and then storing and regasifying LNG in ultra-low temperature cold storage tanks Compared with the CNG mode, the gas supply mode has higher transmission efficiency, stronger safety and reliability, and can better solve the problem of urban natural gas sources.

Characteristics of LNG

1. Low temperature, large gas-liquid expansion ratio, high energy efficiency, easy to transport and store.

1 standard cubic meter of natural gas has a thermal mass of about 9300 kcal

1 ton of LNG can produce 1350 standard cubic meters of natural gas, which can generate 8300 degrees of electricity.

2. Clean energy – LNG is considered to be the cleanest fossil energy on earth!

The sulfur content of LNG is extremely low. If 2.6 million tons/year of LNG is used for power generation, it will reduce SO2 emissions by about 450,000 tons (roughly equivalent to twice the annual SO2 emissions in Fujian) compared with coal (lignite). Stop the expansion of the acid rain trend.

Natural gas power generation NOX and CO2 emissions are only 20% and 50% of coal-fired power plants

High safety performance – determined by the excellent physical and chemical properties of LNG! After gasification, it is lighter than air, colorless, odorless and non-toxic.

High ignition point: auto-ignition temperature is about 450℃; narrow combustion range: 5%-15%; lighter than air, easy to diffuse!

As an energy source, LNG has the following characteristics:

LNG basically does not produce pollution after combustion.

 The reliability of LNG supply is guaranteed by the contract and operation of the entire chain.

 The safety of LNG is fully guaranteed by strictly implementing a series of international standards in the design, construction and production process. LNG has been in operation for 30 years without any serious accident.

 LNG, as an energy source for power generation, is conducive to the peak regulation, safe operation and optimization of the power grid and the improvement of the power supply structure.

As urban energy, LNG can greatly improve the stability, safety and economy of gas supply.

Wide range of uses for LNG

As a clean fuel, LNG will surely become one of the main energy sources in the new century. Outline its uses, mainly including:

Peak load and accident peak shaving used for urban gas supply

Used as the main gas source for pipeline gas supply in large and medium cities

Used as gas source for gasification of LNG community

Used as fuel for car refueling

used as aircraft fuel

Cold energy utilization of LNG

Distributed Energy System

Post time: Apr-19-2022