- LNG is natural gas that has been processed to be transported in liquid form at atmospheric pressure and at -260°F (-162°C).
- It gives greater storage capacity in less space: the occupied volume is 1/600 times in liquid state.
- Regasification occurs at room temperature, through a heat exchanger or vaporizer.
- It is transported by land or sea in special cryogenic tanks (isocontainers).
- It is odorless, colorless, non-toxic.
- It only burns when it comes into contact with oxygen at concentrations of 5 to 15%.
- It is the best alternative to supply fuel and power to remote or isolated areas, where there are no pipelines.
WHAT IS LIQUEFIED NATURAL GAS?
When natural gas is extracted from the wells, it often contains other materials and
components that must be disposed of before it can be liquefied:
+ Carbon dioxide
+ Heavy hydrocarbons, also called “condensates”
With this process, we offer 97% methane. The removal of ethane, propane and other hydrocarbons is controlled by a liquid removal unit, which can be integrated in the liquefaction process.
To convert natural gas into liquid, the treated gas is cooled to approximately −260 °F (-162 °C), which is the temperature at which methane CH4 – its main component – is converted to liquid form. The liquefaction process is similar to that of common refrigeration: the refrigerant gases are compressed producing cold liquids, such as propane, ethane / ethylene, methane, nitrogen or mixtures thereof, which then evaporate as they exchange heat with the natural gas stream. In this way, natural gas cools to the point where it becomes liquid. Once the gas has been liquefied, it is subjected to a Joule-Thomson effect or expansion with extraction of work to be able to store it at atmospheric pressure. The produced LNG is stored in special isocontainers to be later transferred to special transport tanks.
As mentioned before, LNG is stored at −260 °F (-162 °C) and at atmospheric pressure in special cryogenic tanks for low temperature. The typical LNG tank has two concentric tanks. Safety and resistance are the main design considerations when building these tanks, which are designed to withstand earthquakes and extreme weather conditions (temperature, wind, hail, radiation, atmospheric pressure, etc.).
Through a regasification process, the LNG returns to its original gaseous state.
To do this, it goes from the liquid state in which it is found in the cryogenic containers, to the ambient temperature through a vaporizer. With this process, it meets the appropriate conditions for its use.
This transportation method for LNG is the most efficient for those customers away from the pipeline distribution network.
As a consequence of the technological development in LNG applications and the commitments established by the Kyoto Protocol and the Paris Agreement, the consumption of natural gas is promoted as an efficient and clean source for energy generation.
Natural gas allows impurities such as water, heavy hydrocarbons and other particles to be eliminated during the liquefaction process, thereby reducing the impact on the environment.