What is Liquefied natural gas ( LNG ) ?



Liquefied natural gas or LNG refers to natural gas that has been temporarily converted into a liquid state for storage or transportation in large volumes.

LNG mostly consists of methane (more than 90%) and small amounts of ethane, propane, butane and some other heavy alkanes. The LNG refining process can be designed in such a way that the final product produced contains 100% methane.

LNG has a volume equal to 1/600 of the volume of natural gas in gaseous state. Liquid gas is odorless, colorless, non-toxic and non-corrosive. The dangers that this gas can cause include flaming, freezing and suffocation. The energy density of LNG is 60% of diesel fuel.

LNG gas production process

The condensation process includes the removal of certain compounds such as dust, acid gases, helium, water and heavy hydrocarbons, which cause problems for the gas in the downward flow (gas transfer in pipes). After removing the above, natural gas is cooled at a pressure equivalent to atmospheric pressure and a temperature of -162 degrees Celsius. (Maximum gas pressure for transmission applications is 25 kPa or 3.6 PSI).

Reducing the volume of gas in conditions where pipelines are not available will save money in long routes. In cases where it is not economical or operational to transport natural gas through a pipeline, it can be transported through specially designed LNG carriers or road tankers.

In consumer markets, LNG turns into gas again. The density of LNG varies from approximately 0.41 to 0.5 kg/liter, which is a function of temperature, pressure, and composition. The heating value of LNG at the highest level reaches 24 megajoules per liter at a temperature of -164 degrees Celsius. The lowest heating rate of LNG is 21 megajoules per liter.

LNG gas production process
LNG gas production process

Kian Group International Company is the largest supplier and exporter of petroleum products in Turkey, which with the cooperation of its representative in Iran , Kian Petroleum Company, is able to supply various oil, mineral and steel products directly from the doors of Iranian factories.

LNG production steps

There are 4 main stages in the production of liquid gas from natural gas:

  1. Separation of impurities: these impurities are mainly composed of carbon dioxide and in some cases sulfur compounds.
  2. Water separation: If there is water in the liquid gas, it turns into ice crystals and clogs the pipes.
  3. Separation of hydrocarbons: All heavy hydrocarbons are separated and only methane and ethane remain.
  4. Converting gas to liquid: The remaining gas is cooled to -160 degrees Celsius and turns into liquid state at atmospheric pressure.
  5. Storage in the container: liquefied natural gas is stored in special insulated tanks to be transported to the destination.
  6. Transportation to the destination country: Liquid gas is delivered to special cryogenic tanks. During transportation, usually part of the evaporated gas reaches the fuel consumption of the ship’s engine.
  7. Unloading of LNG at the destination: At the destination port, liquid natural gas is unloaded to be consumed when needed.
  8. Conversion of LNG to gas: Before consumption, LNG is converted to gas again. In the process of turning it back into gas, a lot of cold is released, which can be used, for example, for freezing food or other commercial uses.

LNG resources

LNG can be obtained from 4 sources:

  1. Non-combined natural gas: after drying and desulfurization, the sour gas from the natural gas field can be separated and get propane and butane.
  2. Combined natural gas: after separating and refining natural gas with crude oil, propane and butane can also be separated.
  3. Crude oil: Part of propane and butane remains in crude oil, which can be obtained by refining crude oil.
  4. Also, in the process of molecular breaking or the process of increasing the octane of gasoline, propane and butane are obtained as side products.

LNG business

The first commercial shipment of LNG was shipped from Algeria to the UK in 1964.

In cases where natural gas transmission through pipelines is not economical or operational, liquid natural gas transmission can be used. Transport liquefied natural gas through specially designed sea vessels or road tankers.

Buying and selling liquefied natural gas requires a huge investment due to the provision of port facilities, storage in loading ports, unloading, construction of special ships for LNG transportation. At the same time, the sale price of liquefied natural gas is low. Therefore, at first, a long contract of 15-20 years should be concluded between the seller and the buyer, and the pricing and other conditions of the necessary agreements should be made.

LNG storage tanks

Type one tanks or single tank:
In this type of tanks, one tank is inside another tank. The inner tank is responsible for keeping the liquid with a very low temperature. The outer tank, which is usually made of carbon steel, is responsible for insulating the inner tank.

In addition, the internal tanks are made of nickel-containing steels. In order to prevent leakage in this system, gas entry and discharge is done through the roof of the tank.

Double containment tanks:
The only difference between this tank and the first type is that the external tank can store this liquefied gas when there is a leak in the internal tank.

Type 3 tanks or full containment tanks:
In this type of tanks, all the possible ways of gas leakage to the outside have been considered. The outer tanks prevent the exit of gases created by the internal tanks to the outside.

Kian International Group Company is the largest exporter of LPG in Iran and the representative of Kian Petroleum Company in Iran to supply and supply all products of the Energy Exchange and Iran Commodity Exchange for various uses of industries and by selling products of the Energy Exchange and Iran. Commodity Exchange in Ring International, while meeting the needs of customers in foreign markets, has provided the possibility of offering a variety of steel products at competitive prices to domestic and foreign markets, which shows the high potential of the company in the field of steel.

For more information on the latest and latest supply announcements, contact our sales experts in Iran and Turkey.

Iran Office: 00983535227500 – 00989120525658

Turkey Office: 00905387445869

Email: export@kiangroup.com