Liquefied Natural Gas (LNG): What It Is and Why We Use It

Compared to other fossil fuels, natural gas and liquefied natural gas (LNG) have long been touted as top contenders in the energy transition to renewable energy. That’s because carbon dioxide (“CO2”) emissions from the combustion of natural gas are about half that of coal. Natural gas discharge creates far fewer pollutants, making it a more attractive option with a lower carbon footprint.  

But what is liquefied natural gas and is it a “clean solution” for our growing energy needs? Let’s explore how LNG is produced, transported, and stored; what it’s used for; how it impacts the environment; and its role in the gas supply market.  

What Is Natural Gas vs. Liquefied Natural Gas?  

Natural gas is found in underground rocks known as reservoirs and can be extracted through drilling wells. The majority of natural gas in the United States is considered fossil fuel.  

Natural gas is transported to processing plants through natural gas pipelines. While traveling through these lines, the gas is purified to become pipeline-quality dry natural gas. Following this process, the natural gas is sent to distribution centers through other pipelines known as feeders.     

Years ago, energy companies needed to find a way to transport natural gas on ocean liners to expand their market beyond local borders. They discovered turning the gas into a liquid form — aka, liquefied natural gas (sometimes mistakenly spelled as “liquified natural gas”) — could help with this problem. This liquid form would enable them to transport and store the substance until it needed to be regasified and used as an energy source elsewhere.  

How Is Liquefied Natural Gas Made?  

Liquefied natural gas is produced through LNG liquefaction at LNG facilities. Liquefaction involves converting natural gas from its gaseous state into a liquid form by cooling it down to -162 degrees Celsius (-260 degrees Fahrenheit). During this refrigeration stage, impurities such as dust and carbon dioxide are removed. By liquefying natural gas, its volume is reduced 600 times, making it far easier to transport and store.  

How Is Liquefied Natural Gas Transported?  

The preferred way of transporting LNG is through insulated pipelines. The pipeline infrastructure moves the LNG from liquefaction facilities to storage facilities, tankers, regasification plants, and possibly export facilities, depending on whether it is to be used locally or abroad.  

Because LNG exports predominantly occur at an intercontinental level, specially designed LNG carriers (ships) are used to transport the substance between export and import terminals. The most frequently used vessel is an LNG tanker, which can carry four or five LNG storage tanks at a time. These tanks are temperature-controlled and capable of withstanding extremely high pressure.  

Once an LNG tanker arrives at an import terminal, the LNG is transferred to large storage tanks. After that, it is compressed, vaporized, and fed into the local gas transmission grid. Alternatively, the LNG can be loaded on trailers and ISO tank containers for distribution to areas that don’t have access to the grid.  

While only a tiny portion of LNG is transported on the road, the demand for this form of distribution is growing.  

How Is Liquefied Natural Gas Regasified?  

Once at a location where there is a gas demand, the LNG is warmed and converted back into its gaseous form. Regasification is most frequently done at import terminals. After the tankers offload the LNG, the substance is stored in tanks until the demand for natural gas rises.  

Regasification plants use seawater to produce the heat required to vaporize LNG in locations with a warm climate. On the other hand, in cooler areas these plants need submerged combustion vaporizers to convert LNG back into its gaseous state. For this reason, colder locations generate more emissions than warmer ones.  

What Is Liquefied Natural Gas Used For? 

source

Once LNG is regasified, it’s transported to residential, commercial, and industrial properties where it is used for many purposes. From day-to-day activities like cooking to larger endeavors such as generating power, LNG is a practical solution for getting natural gas to the places we need it most.  

Residential and Commercial Uses for Natural Gas 

Natural gas is used for many things around the home. The following are just a handful of examples: 

• Cooking 
• Drying 
• Water heating 
• Air conditioning 
• Humidifying 
• Lighting  

Industrial Uses for Natural Gas  

Industrial uses for natural gas abound; the following are some more well-known examples: 

• Generating electricity at power plants 
• Heating buildings and water 
• Fuel 
• Producing (chemicals, fertilizer, hydrogen, etc.) 
• Manufacturing (paper, metal, clothing, etc.) 

Is Liquefied Natural Gas Toxic or Otherwise Dangerous? 

Despite the common perception that LNG is harmful, liquefied natural gas is nontoxic. While it is true that all fuels should be treated with the necessary caution, LNG is significantly less dangerous than other liquid fuels such as gasoline and diesel. 

Compared to other fuels, LNG is marginally flammable. To catch fire, there needs to be between 5% and 15% LNG present in the air that would have to be heated to 580 degrees Celsius (1076 degrees Fahrenheit) to burn. Should this occur, LNG would ignite slowly rather than explode. Therefore, LNG is safer to transport.  

Nevertheless, people should not be exposed to methane vapors in enclosed spaces. Methane is a greenhouse gas that, if inhaled in high concentrations, can cause methane poisoning. In addition, when methane is inhaled, it displaces air, thus depriving people and animals of the oxygen required to breathe.  

Is Liquefied Natural Gas Clean, Renewable Energy?  

Natural gas has 40% less carbon dioxide emissions than coal and an estimated 20% less than oil. For this reason, natural gas or liquefied natural gas is considered a cleaner source of energy than coal and oil.  

However, LNG is far from being a source of clean, renewable energy.  Methane is a greenhouse gas that makes up the most significant part of LNG, and it impacts the environment when leaks accidentally occur during extraction or transportation. After carbon emissions, methane is the most significant cause of climate change.  

Because of the methane problem, the spotlight has recently been focused on the producers of natural gas and liquefied natural gas. These stakeholders are now making every effort to reduce the environmental impact of these substances. They are taking measures to limit the amount of methane and carbon dioxide emitted during their production processes.  

Still, LNG is an improvement from using other fossil fuels like coal and oil. Consequently, some governments argue that LNG is preferred to other fossil fuels while we transition to fully clean, renewable energy. In this context, LNG is referred to as a “transition fuel.” 

How Is Liquefied Petroleum Gas Produced? 

Liquefied petroleum gas (LPG) is a colorless hydrocarbon gas formed when processed by refined crude oil or natural gas. LPG consists of propane or butane (or both) and is used to manufacture, produce fuel for vehicles, and power cogeneration plants. Households also use LPG for heating and cooking.  

Like liquefied natural gas, LPG can also be liquefied to make large-scale transportation and storage possible. The liquefaction of LPG involves storing the gas in high-pressure tanks that are thoroughly sealed to prevent leaks. In addition, since LPG is odorless, small amounts of ethanethiol are added to alert consumers whenever gas leaks occur.  

How Are Liquefied Petroleum Gas and Liquefied Natural Gas Different?  

While LNG and LPG as both gasses, they differ in important ways:  

• LNG consists of predominantly methane, while LPG includes additional components such as nitrogen and carbon dioxide. 
• LPG is liquefied and stored at average temperatures, whereas LNG is liquefied and stored under high pressures and chilling conditions 
• LPG can be used directly from cylinders, while LNG requires regasification with a vaporizer to bring it back to the gas form state. 
• LNG is natural gas converted to liquid through liquefaction, while LPG is a liquefied gas and a byproduct of refining crude oil. 
• LPG weighs two times what air does and is a colorless, odorless, and highly flammable gas, while LNG is a compressed natural gas that is 600 times smaller than the volume of natural gas. 
• LPG is highly combustible, whereas LNG is not. 
• LPG is more commonly used for domestic and commercial purposes, while LNG is mainly used for large-scale electric power generation and as a marine fuel. 

Which Countries Are the Biggest Exporters and Importers of LNG? 

source

The leading exporters of LNG are: 

• Qatar 
• Australia 
• United States 
• Nigeria 
• Algeria 

The primary importers of liquefied natural gas are:  

• Japan 
• South Korea 
• China  
• Germany  

What Is the Role of LNG In the Gas Supply Market?  

While the gas demand declined by 3% in 2020, the need for LNG increased by 1%. However, the LNG market still showed significant volatility, with periods of severe oversupply alternated with periods of peak demand.  

Still, the demand for LNG is steadily growing, and the LNG supply in gas markets may not be able to keep up with the current gas demand, which is expected to increase by 3.4% every year until 2035. This demand will boost LNG trade and the LNG industry as a whole.  

The result is that many new LNG projects are underway. The five most significant projects for 2022 are as follows: 

Qatar 

The North Field Expansion Project will have an LNG production capacity of 110 million tons per year and make Qatar the biggest LNG exporter once the project comes online.  

India 

The Jafrabad Floating Storage and Regasification Unit in India will increase its LNG shipping capacity by 12%. Moreover, it will allow India to process and ship 47.5 million tons of LNG per year.  

United States 

The Rio Grande LNG Plant is set to produce 27 million tons of LNG per annum while reducing emissions by 90% by employing carbon capture storage technology. This project will significantly enhance the U.S. LNG supply.  

Russia  

The Arctic LNG 2 project in Russia aims to produce 19.8 million tons of LNG by 2025. As with the Rio Grande LNG Plant, this project will use advanced technology to make the LNG liquefaction process more efficient.  

Germany  

With the Brunsbüttel LNG Terminal, Germany hopes to become more self-efficient in LNG production. Currently, 90% of their natural gas comes from LNG imports. The terminal is set to produce 5.1 million tons of LNG each year. Norway is also developing the Hammerfest LNG plant to help alleviate Europe’s gas shortage problem.  

Is Liquefied Natural Gas a Long-Term Energy Solution? 

Liquefied natural gas (sometimes spelled as “liquified natural gas”) has several advantages, including the ease of transporting and storing it. This substance is also a vast improvement in using other fossil fuels such as coal and oil, as its production involves fewer harmful emissions.  

However, LNG might not be the best solution long term. Apart from not being a renewable source of energy, the methane emissions from LNG have a detrimental effect on the environment. A clean future will only be possible with clean, renewable energy, such as what we get from solar power, wind power or hydropower, among other sources. 

Brought to you by justenergy.com

All images licensed from Adobe Stock.
Featured image: