What is LNG?
LNG, also known as liquid or liquefied natural gas, is a natural gas predominantly made of methane, which is missed with ethane. The two products are chilled down to liquid state. Doing so allows for ease and safety especially when it comes to issues like non-pressurized packaging and transportation. LNG is naturally odorless, colorless, and it does not contain any toxins and corrosive substances. During the liquefaction process, elements like dust, gases that have acid in them, helium, H2O, and other hydrocarbons are separated from the natural gas. Afterwards, the gas is condensed into a liquid state to the pressure of the atmosphere by chilling it to about -162 degrees Celsius.
What is natural gas?
Natural gas, also referred to as fossil gas, is a naturally occurring type of hydrocarbon gas. Natural gas primarily consists of methane but sometimes may include a wide range of higher alkanes and some percentage of carbon dioxide, helium, and nitrogen. Natural gas is usually formed when layers of decomposing plant and animal matter are exposed to intense amounts of heat and pressure on the surface of the earth.
What is the difference between LPG and natural gas?
LNG is typically a liquefied version of natural gas. Below are some of the key differences between the two types of gas are:
- LNG is easier to transport than natural gas because of its state.
- LNG is typically 600 times smaller than natural gas.
Other differences between the two can be seen in their advantages and their applications.
Advantages of LNG over natural gas
Below are some areas where LNG is more beneficial than natural gas;
One of the main advantages that LNG has over natural gas lies in the area of transportation. Transportation of LNG gas refers to the movement of natural gas in liquid form. There are two methods of transportation that can be used. They are:
This is the most preferred method of transporting liquefied natural gas. The LNG pipeline infrastructures are designed in such a way that they take the liquefied natural gas between liquefaction facilities and storage tanks. It also takes the liquefied gas from storage facilities to tankers and from the tankers to the re-gasification facilities. Usually, LNG is much denser than natural gas in its compressed form. This means that when transporting LNG through pipelines is easier because more amounts of gas can be transported at the same volume flow than the later.
The downside is that pipelines for transporting LNG are harder and costlier to construct. One of the difficulties in maintaining the temperature of the has at -160 degrees Celsius, which is the required amount that helps maintain the liquid form of the gas. This means that the pipeline has to feature significant insulation to maintain the low temperature and keep the liquid gas from re-gasifying. The type of insulation required is mechanical insulation like glass foam or a vacuum layer, which is usually costly.
- Transportation using LNG vessels
This is where the LNG is transported using LNG tankers or ships. The ship usually transports large amounts of LNG between export and import terminals. The market is packed with a wide range of LNG transportation vessels. However, the most popular one is an LNG tanker. The tanker is made up of a boiler and a pump room. It is usually built with 4 or 5 individual LNG tanks, a bridge, and a ballast tank.
Transportation of natural gas
The safest method of transporting natural gas is through pipelines. Transportation of natural gas requires a sophisticated pipeline system that will allow it to move quickly from one origin to the next. There are three methods of transporting natural gas. They are gathering pipelines, interstate pipelines, and distribution pipelines. Gathering pipelines are made of low-pressure of small-diameter pipes that carry the gas. On the other hand, interstate pipelines closely resemble interstate highway systems, and they are used for transporting natural gas from one state and area to the other. Finally, distribution pipelines are a basic type that isn’t much different from the others.
The transportation advantage
- The advantage of transporting LNG over natural gas is that it is easier to transport liquid than gas.
- Transporting LNG is also safer than later because it is lesser prone to accidents like explosions.
- Natural gas can only be transported by pipeline, whereas LNG can be transported using vessels because it is safe. Therefore, there are more means of transportation available than the latter.
- Transporting liquefied natural gas is also more convenient because you can transport a large amount of gas in the same pipes and time as compared to the latter.
Another advantage that LNG has over natural gas is that it is clean hence safer. As mentioned earlier, LNG is non-toxic, non-corrosive, and does not contain any odor or color. This means that when it is exposed to the environment, it evaporates rapidly. Its evaporation implies that it does not leave any residue in the soil or water, depending on the application and mode of transportation. Therefore, in spills, you can be sure that 100% of the gas will evaporate, leaving nothing behind. The same cannot be said about natural gas in its original form.
Additionally, LNG is made up of methane and combustion primary products like water vapor and carbon dioxide. This means that the combustion of liquefied gas only leads to the release of small quantities of nitrogen oxides, Sulphur dioxide, and lower levels of carbon monoxide and other reactive hydrocarbons. According to safety records of liquefied natural gases, they are incredibly safe. The same cannot be said about natural gas, which is extremely hazardous to the environment and highly flammable hence risky.
Other advantages of LNG include:
- LNG also leads to reduced shipping emissions. What happens is that liquefied natural gas provides the ability to minimize the emission of nitrogen oxide and Sulphur significantly. According to authorities in the field, LNG could result in up to 20% reduction in the amount of carbon emission.
- LNG is a more economical source of energy as opposed to black products
- Lager amounts of LNG can be stored and transported at extremely low pressure.
- It is a clean fuel that contributes to improved product quality where it is applied. It also leads to reduced maintenance costs when it is used in various products.
LNG fuelled ships are able to emit almost zero sulphur oxide emissions, and the lower carbon content of LNG compared to traditional ship fuels enables a 20-25% reduction of carbon
dioxide (CO2) emissions.