Cryogenic tanks play a vital role in the LNG supply chain. Beyond ensuring smooth distribution, this technology keeps LNG in its liquid state, enabling it to be transported over thousands of kilometers.
That’s why these tanks are a key pillar of global energy security. Curious why their role is so crucial? Let’s dive in.
What Is a Cryogenic Tank?
A cryogenic tank is a specialized container designed to store and transport materials at extremely low temperatures, typically below −150°C (−238°F).
At such frigid temperatures, gases like nitrogen, oxygen, argon, helium, or LNG (Liquefied Natural Gas) remain in liquid form, drastically reducing their volume and making them easier to transport.
The liquefaction process doesn’t happen inside the tank. It’s done in dedicated liquefaction facilities. Once the gas has been converted into a liquid, the cryogenic tank’s job is to maintain the correct temperature and pressure so it doesn’t revert to gas.
To withstand such extreme conditions, the tank walls are made from low-temperature-resistant materials such as stainless steel, 9% nickel steel alloy, or aluminum alloy, combined with advanced thermal insulation layers.
This design prevents external heat from entering and keeps cryogenic liquids stable during both storage and transport.
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How Do Cryogenic Tanks Work?
Cryogenic tanks store liquids at extremely low temperatures to keep them in liquid form. For example, liquid nitrogen, liquid oxygen, liquid argon, liquid helium, or LNG are stored between −150°C and −269°C, depending on the substance.
Storing these gases as liquids is far more efficient than in gaseous form, as the volume can shrink hundreds of times.
The key to a cryogenic tank’s function is minimizing heat ingress and controlling internal pressure.
That’s why most tanks feature a double-wall design consisting of:
- Inner wall
- Outer wall
- Vacuum space
The inner wall, which is in direct contact with the cryogenic liquid, is made from low-temperature-resistant materials, typically nickel steel or aluminum alloy.
The outer wall provides mechanical protection against impacts and weather.
The space between the walls is vacuum-sealed and often filled with insulating materials like perlite or multi-layer insulation. This vacuum space blocks heat transfer through conduction and convection.
With proper insulation, cryogenic liquids can remain stable for months with a very low boil-off rate. This ensures the gas doesn’t evaporate before it’s needed for use in medical, energy, or research industries.
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The Key Roles of Cryogenic Tanks in LNG
Cryogenic tanks are critical components in the LNG supply chain, not just to keep LNG cold and liquid, but also to ensure it’s stored and transported safely.
LNG Storage
Cryogenic tanks are designed to keep LNG at around −162°C. Liquefying LNG reduces its volume to about 1/600 of its original gaseous volume, making it far more efficient to store in large quantities.
Large-capacity LNG storage tanks are typically used at liquefaction plants and receiving terminals. They maintain low boil-off rates so LNG can be stored for weeks or even months, ready to meet industrial or power generation needs whenever required.
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LNG Transportation
Cryogenic tanks are essential for transporting LNG both on land and at sea. Cryogenic tank trucks handle short- to medium-distance deliveries, while LNG carriers transport hundreds of thousands of cubic meters across international waters.
These tanks are built from materials that can withstand extreme cold, minimizing natural boil-off during transit so that LNG arrives at its destination in optimal volume.
LNG Distribution and Terminals
At LNG receiving terminals, cryogenic tanks act as buffers between incoming shipments and end-user demand.
After LNG is unloaded from a ship, it’s stored in massive cryogenic tanks with capacities in the hundreds of thousands of cubic meters. From there, LNG is pumped to regasification facilities where it’s warmed back into gaseous form before being fed into pipeline networks.
LNG terminals equipped with cryogenic tanks serve as vital nodes in the global energy supply chain by:
- Ensuring a stable supply despite demand fluctuations or shipment schedules
- Enabling LNG imports for countries without natural gas reserves
- Supporting energy diversification and boosting national energy security
In addition to onshore terminals, there are also Floating Storage Regasification Units (FSRUs), which serve as offshore floating terminals.
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Types of Cryogenic Tanks for LNG
LNG cryogenic tanks are generally categorized by their load-bearing structure and installation method. Common types include:
Single Containment Tank (SCT)
The most common type is due to its lower cost and faster construction time. It has an inner nickel-alloy wall to handle cryogenic temperatures and an outer carbon steel wall to contain low-pressure vapor.
However, SCTs lack a secondary internal barrier, so leaks could release vapor directly into the environment.
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Double Containment Tank (DCT)
An SCT upgrade, the DCT has an additional outer wall (without a roof) to contain LNG spills. This design provides better protection and greater resilience to external hazards.
Full Containment Tank (FCT)
The safest LNG tank design, both the outer wall and roof can contain spills and gas vapor. The downside: it’s the most expensive and time-consuming to build.
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Above-Ground & In-Ground Tanks
Above-ground tanks are constructed above the surface and are the most common choice due to their simpler construction and relatively lower building costs.
This type is widely used in large-scale LNG facilities such as:
- Qatar LNG Plant (Ras Laffan)
- Gorgon LNG Project (Australia)
- Sabine Pass LNG Terminal (United States)
In contrast, in-ground tanks are embedded below the surface and equipped with three protective layers to withstand pressure, extreme temperatures, and shock.
This design offers enhanced protection against earthquakes and potential external threats, making it suitable for disaster-prone regions. Examples of implementation include:
- Tokyo Gas LNG Terminal (Japan)
- KOGAS LNG Terminal (South Korea)
- Taiwan LNG Terminal (Taichung)
Cryogenic tanks are more than just containers. They’re the backbone that keeps LNG safe, mobile, and ready for use at any time.
This technology ensures uninterrupted energy flow, strengthening energy security while enabling a more reliable global energy trade.
References:
- BCGA. Accessed 2025. Cryogenic Tanks
- Sngastank. Accessed 2025. How Cryogenic Storage Tanks Work
