Liquefied natural gas

Natural gas is a type of fuel.

It is mostly made of methane. To move it, we turn it into a liquid. We do this by making it very cold. This makes the gas take up much less space.

Now it can fit on big ships. We clean the gas first to remove dust and water. Then we cool it down. This makes it easy to carry to other lands. It is a great way to share energy.

Natural gas is a fuel mostly made of methane.

To move it easily, we turn it into a liquid. This is called liquefied natural gas, or LNG.

Making LNG takes several steps. First, we clean the gas. This removes things like water and dust. Next, we cool the gas down. We must make it very cold. It reaches temperatures between -145 °C and -163 °C. This cooling makes the gas take up much less space. In fact, it takes up only 1/600th of its original size!

Because it is small, we can carry it on big ships. These ships use special tanks. The tanks have two walls with a vacuum between them. This helps keep the heat out. Once the LNG reaches its destination, we use regasification. This is a way to turn the liquid back into gas. Then, it goes into pipes to reach homes.

Many countries trade LNG. The United States, Australia, and Qatar export a lot. China, Japan, and South Korea buy the most.

Liquefied natural gas, or LNG, is a very useful way to move energy around the world. It is mostly made of methane, which is a type of natural gas.

By cooling the gas, we turn it into a liquid. This makes it much easier and safer to store and move. When it is a liquid, it takes up only 1/600th of the space it did as a gas.

This small size allows us to carry huge amounts of energy in ships or trucks. LNG is colorless and odorless, but it can be dangerous if it catches fire or causes freezing.

The way it works involves several careful steps. First, the gas must be cleaned to remove things like water, dust, and carbon dioxide. These parts could cause problems later in the machines.

Next, the gas goes into a liquefaction unit. Here, it is cooled to between -145 °C and -163 °C. This often happens by passing the gas through tubes and using a cold refrigerant. Finally, the liquid is kept in special tanks with double walls. A vacuum between the walls helps keep the heat out so the liquid stays cold.

People have been studying how gases work for a long time. In the middle of the 1600s, Robert Boyle studied how pressure and volume relate. Later, Karol Olszewski liquefied methane in 1886. In 1918, the U.S. government used large-scale liquefaction to get helium for British dirigibles.

In 1937, Lee Twomey received patents for making this process work on a large scale. He wanted to use the liquid to help provide energy during very cold weather. These early discoveries paved the way for the global energy market we see today.

Today, many countries rely on LNG for their power. As of 2023, the United States, Australia, and Qatar were the top exporters.

On the other side, China, Japan, and South Korea were the biggest importers. In the United States, the industry grew quickly after a boom in gas production. The U.S. exported a lot of LNG in 2023. Some of the biggest companies in this business include Cheniere Energy, Freeport LNG, and Venture Global LNG.

You can think of LNG like a sponge that has been squeezed very tight. Just as a sponge holds a lot of water in a small shape, LNG holds a lot of energy in a small volume.

When the liquid reaches its destination, it goes through regasification. This is a process where the liquid is heated back into a gas. Once it is a gas again, it can flow through pipes to reach homes and businesses. This allows energy to travel across oceans to reach people who need it.

Liquefied natural gas, or LNG, is a highly efficient way to transport energy across the globe. It consists primarily of methane, a simple hydrocarbon with the chemical formula CH4. It also contains smaller amounts of ethane, propane, butane, and nitrogen. By cooling this natural gas into a liquid state, it becomes much easier to manage. In its liquid form, the gas occupies only about 1/600th of the volume it would take as a gas at standard temperature and pressure.

This massive reduction in volume allows huge amounts of energy to be moved by ship or truck. While LNG is colorless, odorless, and non-toxic, it presents hazards like flammability once it vaporizes. It can also cause freezing or asphyxiation if handled improperly.

The liquefaction process is a precise sequence of chemical and thermal steps. First, the feedstock gas undergoes pre-treatment to remove impurities. Components like water, carbon dioxide, hydrogen sulfide, mercury, and heavy hydrocarbons must be removed. If these remained, they could freeze and cause damage to the machinery downstream.

Once purified, the gas enters a liquefaction unit. Here, the gas is cooled to temperatures between −145 °C and −163 °C. This is often achieved by circulating the gas through aluminum tube coils. A compressed refrigerant is used to absorb the heat from the gas. As the refrigerant vaporizes, the heat transfer causes the gas in the coils to cool until it condenses into a liquid.

There are several different methods used to achieve this cooling. One historical method is the Linde process, which uses the Joule–Thomson effect. This involves cooling the gas by passing it through an orifice, causing it to expand and drop in temperature. A more modern version is the Optimized Cascade Process developed by Phillips Petroleum Company. This method uses three successive refrigeration cycles to increase efficiency. It uses propane for precooling, ethylene or ethane for intermediate cooling, and methane for the final liquefaction.

This stepwise approach provides better operational stability and thermodynamic efficiency.

The history of LNG is rooted in the scientific study of gases. In the 17th century, Robert Boyle discovered the relationship between gas pressure and volume. Later, in 1886, Karol Olszewski successfully liquefied methane. The first large-scale use of liquefaction in the United States occurred in 1918. During this time, the U.S. government liquefied natural gas to extract helium. This helium was needed for British dirigibles during World War I.

In 1937, Lee Twomey patented a process for large-scale liquefaction. He intended to use the liquid to support energy loads during cold weather snaps.

Early attempts at commercial storage faced significant challenges. In 1940, the East Ohio Gas Company built the first full-scale commercial LNG plant in Cleveland, Ohio. The plant used large spheres to store the liquid. However, a cylindrical tank ruptured in 1944, leading to a fire that caused 130 fatalities. This tragedy delayed the industry for years. It took new research into low-temperature alloys and better insulation to revive the field. By 1959, the Methane Pioneer ship delivered LNG from the U.S. to Great Britain. This helped restart the global industry and led to the first purpose-built LNG carrier, the Methane Princess, in 1964.

Today, the energy density of LNG makes it a vital global commodity. Its energy density is approximately 2.4 times that of compressed natural gas (CNG). While its energy density is comparable to propane, it is only 60 percent that of diesel.

The global market is highly concentrated. As of 2023, the United States, Australia, and Qatar held the most export capacity. Meanwhile, China, Japan, and South Korea were the largest importers. The United States has seen a massive boom in production due to hydraulic fracturing. By 2023, the U.S. had become the world's largest exporter, moving significant volumes of gas annually.

Once the LNG reaches its destination, it must be returned to a gaseous state through regasification. The liquid is pumped into a vaporizer and heated until it turns back into gas.

This gas is then sent through pipeline networks to reach homes and industries. This entire cycle connects distant energy sources to local consumers. The industry remains complex, with production concentrated in a few areas. This can create choke points in the global supply chain, as seen when political conflicts affect major exporters like Qatar.