The rapid development of modern high-end manufacturing, medical and health, aerospace and new energy industries is inseparable from the support of ultra-low temperature environment and inert protective atmosphere. Conventional refrigeration equipment and ordinary compressed gas cannot meet such high-precision, high-severity production and experimental needs. Cryogenic gas is widely used in all walks of life by virtue of its extreme low-temperature characteristics and high-efficiency energy storage advantages. This article will help you fully grasp the industrial value and use of cryogenic gas.
Cryogenic gas refers to industrial gas cooled to ultra-low temperature, and the general industry definition standard is that the temperature is lower than -150 ℃. In the industrial operation scene, low-temperature gas is mostly stored, transported and used in liquid form, which is also professionally called cryogenic refrigerant. The boiling point of this kind of gas is generally much lower than -90 ℃, and the liquid will quickly vaporize after absorbing heat, resulting in a strong cooling effect, which is also the core advantage of its difference from ordinary industrial gases.
The reason why low-temperature industrial gas has become a high-end industrial rigid demand material is derived from three irreplaceable characteristics.
According to the market application scale and scene positioning, low-temperature industrial gases can be divided into general-purpose industrial low-temperature gases and high-end low-temperature rare gases. The boiling point, physical and chemical properties and applicable scenarios of different categories are very different, which is the core basis for project selection.
Common cryogenic industrial gases cover more than 90% of industrial and livelihood low-temperature scenes.
Liquid nitrogen (LN₂): boiling point -196 ℃, colorless, tasteless, inert, non-flammable, safe and stable. It is currently the world’s largest and most versatile low-temperature industrial gas, suitable for the industry-wide basic low-temperature and inert protection scenarios.
Liquid oxygen (LOX): boiling point -183 ℃, light blue liquid, is a strong oxidant, itself does not burn but can be strong combustion. Liquid oxygen is the core raw material for heavy industry smelting, medical oxygen supply and aviation propulsion.
Liquid argon (LAr): boiling point -186 ℃, inert rare gas, chemical properties are extremely stable. Liquid argon is used for high-end protection scenarios such as welding protection, special steel smelting, and semiconductor precision manufacturing.
Liquid helium (LHe): boiling point -269 ℃, is the lowest known boiling point of industrial gas, to achieve extreme ultra-low temperature environment. High scarcity and high cost. Liquid helium is used in precision scenarios such as superconducting equipment, semiconductor manufacturing, and high-end scientific research.
Liquid hydrogen (LH₂): boiling point -253 ℃, clean and combustible energy, the combustion product is only water. It is the core low-temperature raw material for aerospace fuel, new energy storage and fuel cell industry.
Liquid methane (LNG): boiling point -161 ℃, clean combustible fuel. Widely used in industrial heating, civil gas, low-temperature energy storage and other scenarios.
Neon, krypton and xenon are extracted from air separation tail gas in trace amounts, with extremely low atmospheric content, difficult purification and high unit price. These rare gases have special photoelectric and low temperature properties and are only used in high-end precision industries.
Neon gas boiling point -246 degrees C, unit volume cooling capacity is 40 times that of liquid helium, the main high-end precision cooling, laser equipment, semiconductor lithography scene.
Krypton gas boiling point -153 ℃, high density, strong stability. Krypton gas is used for high-end lighting, aviation runway lights, special lasers and semiconductor process aids.
Xenon gas boiling point -108 ℃, is the most dense rare gas. Xenon gas is used in satellite ion propulsion, high-end medical anesthesia, precision chip etching and other cutting-edge fields.
With the advantages of safety, cheapness and stability, liquid nitrogen covers many fields of food, medical treatment, manufacturing and scientific research, and is a low temperature material just needed by industry.
Liquid nitrogen in the food industry is used for extreme freezing and cryogenic grinding of IQF monomers. It can quickly lock the moisture, nutrition and taste of food materials, and avoid the deterioration of food materials and taste deterioration caused by traditional freezing.
Liquid nitrogen is the core cryopreservation medium for cells, tissues, embryos and biological samples in medical and biological fields. At the same time, it can be used for low-temperature physical therapy, remove skin lesions, and also assist in cooling some medical equipment.
Liquid nitrogen is used in industrial manufacturing, cold-shrink assembly of metal parts, and low-temperature deburring of rubber and plastics. It can also be used as inert gas to complete pipeline purging and tank inert protection to prevent oxidation and explosion risks.
In addition, LN₂ can also be used for laboratory equipment cooling, stage smoke effects, low-temperature ice and other auxiliary scenes, which is extremely practical.
It should be noted that although liquid nitrogen is non-toxic and inert, it is easy to cause frostbite at ultra-low temperature. After vaporization, LN₂will occupy oxygen in the confined space, and there is a risk of suffocation and tank overpressure. The operation needs to be strictly regulated.
Liquid oxygen has both high purity and strong oxidation characteristics, is the core raw material of heavy industry to improve quality and efficiency, medical life protection, supply and demand scale is firmly in the forefront of the industry.
Liquid oxygen In heavy industry is used in the steel smelting process to quickly remove impurities such as carbon, silicon, and phosphorus from molten iron to improve steel quality and production efficiency. At the same time, it is suitable for metal cutting, welding, chemical oxidation reaction, glass and cement combustion, sewage aeration treatment and other processes.
Liquid oxygen is the mainstream rocket oxidizer in the aerospace field, which can be matched with liquid hydrogen, kerosene and other fuels to provide strong power for launch vehicles and aerospace equipment.
High-purity liquid oxygen in the medical is the core of the hospitals centralized oxygen supply system. After vaporization, the liquid can be transported to the operating room, ICU, and ward to provide life support for respiratory failure, chronic obstructive pulmonary disease, and emergency patients. It is a key material for emergency medical care.
The extreme inertness of liquid argon makes it an exclusive protective gas for high-temperature, high-precision manufacturing scenarios, effectively preventing material oxidation loss.
liquid argon in the welding industry is vaporized as a protective gas for TIG/MIG welding, which is suitable for welding of active metals such as stainless steel, aluminum alloy and titanium alloy. Can be isolated from the air, to avoid weld oxidation, pores, cracks, to ensure the welding accuracy.
Liquid argon in the metallurgical industry is used for stainless steel AOD refining and non-ferrous metal degassing stirring. It can accurately remove metal impurities, protect the stability of alloy composition, and improve the quality of special steel and aluminum products.
Ultra-high purity argon in the semiconductor and electronics industry, can build dust-free inert atmosphere. Adapted to monocrystalline silicon growth, plasma etching, coating, ion implantation and other core chip processes, is the basic material for high-end electronic manufacturing.
Liquid helium is currently the lowest temperature commercially available refrigerant and the only industrial medium that can maintain the superconducting state.
Its largest commercial scenario is the cooling of superconducting magnets for medical MRI and laboratory NMR equipment. Ensure that the magnetic field of the equipment is stable and accurate imaging.
At the same time, liquid helium is used in cutting-edge scientific research fields such as particle colliders, quantum computing, and ultra-low temperature physics experiments.
As helium is a non-renewable scarce resource, the industry has now popularized low-volatile, zero-volatile liquid helium equipment, with cryogenic refrigerators, significantly reducing helium consumption and use costs.
Liquid hydrogen clean, high energy, zero carbon emissions, is the core carrier of the global new energy transformation and aerospace industry.
In the field of aerospace, liquid hydrogen with liquid oxygen is a classic low-temperature propulsion combination, which is widely used in various types of launch vehicles with excellent dynamic performance.
Liquid hydrogen can realize large-scale and long-distance hydrogen energy storage and transportation in the field of new energy, and solve the geographical limitation of pipeline hydrogen transmission. Can be used for fuel cell vehicles, ships, aviation power, while supporting the grid peak, new energy storage.
Neon, krypton, xenon three types of rare gases, relying on special physical and chemical properties, focusing on high-end segments, high added value.
Neon is used in scenarios such as semiconductor lithography excimer lasers, low-temperature cooling of high-end equipment, and high-pressure indicators.
Krypton gas is used for energy-saving lamps, aviation lighting, insulating glass insulation, special laser equipment.
As a high-quality ion propellant, xenon gas is used for satellite attitude adjustment and deep space exploration, and is suitable for high-end medical anesthesia and chip precision etching process.
The core of cryogenic industrial gas production is the use of different gas boiling point differences, through cryogenic liquefaction, distillation purification to achieve separation, the mainstream process is divided into three categories.
Air separation cryogenic gas plant mainly used for the production of liquid nitrogen, liquid oxygen, liquid argon and rare gases. The air separation process is air filtration and compression, molecular sieve removal, cryogenic heat exchange liquefaction, double-tower distillation separation, and finally purified to obtain high-purity liquid cryogenic industrial gas, which can achieve large-scale mass production and purity of more than 99.999%.
The process of hydrogen liquefaction first through natural gas reforming, electrolysis of water and other ways to produce hydrogen, and then through compression purification, liquid nitrogen pre-cooling, multi-stage low-temperature expansion refrigeration. At the same time, the conversion of positive secondary hydrogen is completed, and the final liquefaction is liquid hydrogen, which consumes high energy and requires strict equipment accuracy.
Helium is mainly extracted from natural gas tail gas, and high-purity liquid helium is obtained through impurity removal, crude helium purification, and multi-stage ultra-low temperature refrigeration liquefaction. Due to the extremely low boiling point, it is the category with the highest technical difficulty and the largest energy consumption among all cryogenic liquefaction processes.
The core principle is to maximize heat insulation, reduce volatilization, eliminate the risk of overpressure, and adapt to different scenarios with corresponding special equipment.
Laboratory, small scene use, the use of small vacuum Dewar bottle, small capacity, portability, can meet the short-term micro gas demand.
Industrial plant area, large-scale gas scene, using vertical/horizontal vacuum insulation cryogenic storage tank. With pearlescent sand insulation, multi-layer insulation structure, equipped with pressure relief valve, liquid level meter, vaporization system, can achieve long-term stable liquid storage and automatic gas supply.
For special cryogenic gases such as liquid helium and liquid hydrogen, it is necessary to adopt a special sealed storage tank for ultra-low volatilization to solve the problem of volatilization and leakage of extremely low-temperature media. Liquid oxygen storage tanks must be made of special oxidation-resistant materials to eliminate the risk of combustion.
Short-distance industrial transportation uses cryogenic storage tanker, suitable for liquid nitrogen, liquid oxygen, liquid argon and other conventional media, sufficient capacity, flexible scheduling.
ISO cryogenic container tanks are used for long-distance and cross-regional transportation, which can be adapted to multimodal transportation by road, railway and sea. The sealing and heat insulation meet the standards and support cross-border bulk transportation.
In special scenarios such as biological samples, dry transport tanks are used to adsorb liquid nitrogen in porous media without free liquid, which can meet air transport specifications.
Although cryogenic gas is suitable for many industries, but ultra-low temperature, large expansion ratio, special chemical properties, bring many operational risks, is the focus of industrial control.
Aiming at the technical difficulties and safety pain points of the whole chain of cryogenic gas production, liquefaction, storage and transportation, and application, the Fullcryo provides an integrated customized cryogenic system solution to cover the requirements of the whole scenario project.
We provide a full range of cryogenic equipment and engineering services covering air separation equipment, gas purification systems, liquid hydrogen liquefaction equipment and liquid helium liquefaction equipment, rare gas extraction and purification equipments, cryogenic energy storage and storage tanks, vacuum insulation systems, etc.
By combining cryogenic process technology, advanced refrigeration systems, and customized engineering capabilities, Fullcryo can develop solutions based on specific gas types, production capacities, purity requirements, storage conditions, and operating environments.
Mainstream commonly used category for liquid nitrogen, liquid oxygen, liquid argon, liquid helium, liquid hydrogen. Among them, the largest amount of liquid nitrogen, the most cost-effective, is the first choice for general industry, liquid oxygen, liquid argon focus on heavy industry and precision manufacturing, liquid helium, liquid hydrogen for high-end scientific research and new energy scenarios.
Liquid helium has the lowest boiling point of -269 ℃, which is the lowest known industrial medium and the only core refrigerant that can support the operation of superconducting equipment.
Ordinary compressed gas is stored at room temperature and high pressure, with high pressure and limited gas storage capacity. cryogenicindustrial gas is stored by ultra-low temperature liquefaction, with great gas storage capacity under normal pressure/low pressure, higher storage and transportation efficiency, and unique cryogenic refrigeration and inert protection characteristics.
Cryogenic industrial gas equipment includes air compressor unit, molecular sieve purification system, main heat exchanger, turbo expander, cryogenic distillation column, liquefaction unit, purification device, cryogenic storage tank and automatic control system. Complete air separation equipment is the mainstream configuration for mass production.
Vacuum multi-layer insulated cryogenic tank with compliant pressure relief device and liquid level pressure monitoring system is required. Regularly check the thermal insulation performance and pressure relief components of the cryogenic storage tank, control the ambient temperature, and match the confined space with ventilation and oxygen monitoring equipment to reduce the volatilization of the medium and potential safety hazards.
Different categories of cryogenic industrial gases, with differentiated low-temperature, inert, oxidation, flammable characteristics, covering the whole scene from civil demand, heavy industrial production to high-end cutting-edge scientific research needs.
Relying on professional cryogenic system technology and engineering experience, the Fullcryo can provide full-category and full-process cryogenic industrial gas project solutions to escort the stable operation of various industrial and scientific research projects.
