The large-scale popularization of renewable energy has completely reconstructed the global energy structure. But long-term energy storage and long-distance energy transportation become the core bottleneck of new energy industrialization landing. With its core advantages such as ultra-high volume energy density, long-distance efficient transportation and large-scale energy storage, liquid hydrogen (LH) has become a breakthrough solution for the large-scale development of hydrogen energy and the cross-border circulation of green energy, providing core support for the landing of the global hydrogen energy economy.
Liquid hydrogen (LH₂) is the liquid form of hydrogen molecules. The gaseous hydrogen is cooled to below the ultra-low critical temperature to complete the liquefaction, forming a stable storage of liquid hydrogen energy carrier.
Under normal pressure, boiling point of liquid hydrogen only 20.28K(-252.87 ℃), the freezing point is about 14K(-259 ℃), must maintain a very low temperature environment to maintain liquid form.
From physical form looking at it, LH2 is colorless, odorless, free of impurities, and extremely pure. The combustion product is only water, which is 100% clean and zero-carbon energy.
In energy density at the level, the mass energy density of liquid hydrogen ranks first in conventional fuels, up to 33.3 kWh/kg. This feature makes LH2 the preferred fuel for high energy demand scenarios such as aerospace and heavy transportation.
Liquid hydrogen and compressed gaseous hydrogen are the only two pure hydrogen storage and transportation technology routes, the two mass energy density is basically the same, but in the operating conditions, energy consumption, cost, applicable scenarios significantly different.
Operating condition difference: Liquid hydrogen is stored in 20.3K ultra-low temperature and near normal pressure environment; Compressed hydrogen is operated at normal temperature and stored at 350bar or 700bar high pressure.
Storage and transportation density: The volume density of liquid hydrogen is about 70.9 kg/m, which is 1.8 times that of 700bar high-pressure hydrogen and 3 times that of 350bar high-pressure hydrogen. The corresponding volume energy density is 2.36 kWh/L, far higher than the 0.78 of high-pressure hydrogen -1.33 kWh/L.
Energy consumption for preparation: The energy consumption of liquid hydrogen liquefaction is extremely high, consuming 6-15 kWh per kilogram of liquid hydrogen, and the actual industrial energy consumption is more than 10-13 kWh/kg, consuming 30%-45% of the energy of hydrogen itself. The energy consumption of high-pressure hydrogen compression is only 1.7-6.7 kWh/kg, and the energy consumption loss is lower.
Hydrogen energy storage loss: LH2 cannot completely eliminate heat penetration, the average daily evaporation loss is 0.1-5%, large cryogenic liquid hydrogen storage tank can greatly reduce the loss. High-pressure hydrogen has no continuous evaporation loss, and only has micro-penetration leakage after long-term use.
Equipment and cost: Liquid hydrogen needs vacuum insulation cryogenic storage tank, the early equipment investment is high, but the unit volume of hydrogen storage capacity, tank lightweight. High-pressure hydrogen relies on carbon fiber high-pressure tanks, heavy equipment, long-term operation and maintenance costs are higher.
Summary high-pressure hydrogen is more suitable for short-distance transportation within 300km, while LH2 has absolute advantages in medium-and long-distance transportation, large-scale energy storage, cross-border hydrogen energy trade, and heavy equipment energy supply scenarios.
In the large-scale application of new energy and hydrogen energy circulation system, the core value of liquid hydrogen lies in solving the industry pain point of gaseous hydrogen “not stored, not transported far, small scale.
Ultra-high storage and transportation efficiency: Relying on ultra-high bulk density, the same volume tank can store more hydrogen energy. The single carrying capacity of LH2 tank truck can reach several tons, which is much higher than that of high-pressure hydrogen tube bundle truck, which greatly reduces the transportation frequency and adapts to the demand of bulk hydrogen energy transportation.
Higher security: Liquid hydrogen storage does not require a high-pressure environment, avoiding the safety risks of high-pressure tank explosion and pressure leakage. The storage tank covers a small area and is suitable for large-scale centralized energy storage in port hubs, industrial bases and new energy power stations.
Supporting global hydrogen trade: Hydrogen energy pipeline construction investment is large, geographical restrictions are strong, can not achieve cross-regional resource allocation. LH2 can be transported over long distances, allowing green hydrogen in areas rich in scenery resources to be transported to the global hydrogen center.
Make up the new energy short board: lithium batteries can only achieve short-term peak adjustment and cannot solve the problem of seasonal new energy supply and demand mismatch. Liquid hydrogen can convert surplus wind power and photovoltaic energy into hydrogen energy storage, with a storage period of up to several months, realizing cross-seasonal energy dispatch.
Hydrogen liquefaction is the core technology of liquid hydrogen industry. Through multi-stage refrigeration, heat exchange and catalytic conversion, normal temperature gaseous hydrogen is converted into stable ultra-low temperature LH2 energy.
The core equipment of the whole hydrogen liquefaction system includes compressor, 20K vacuum cold box, turbo expander, hydrogen isomerization converter, cryogenic valve and intelligent monitoring system. The equipment accuracy and technical threshold are extremely high.
The core of LH2 storage is double-layer vacuum insulated cryogenic storage tank, which is the key equipment to ensure the stable storage of liquid hydrogen. The inner layer is made of low temperature resistant stainless steel and aluminum alloy, specially carrying ultra-low temperature liquid hydrogen. Under normal circumstances, the outer layer is a carbon steel protective shell, with a high vacuum interlayer between the two shells, and a multi-layer insulation material to insulate the external heat penetration to the greatest extent. The storage tank is equipped with a full set of safety systems, including temperature and pressure monitoring devices, pressure relief valves, bursting discs, evaporative gas emissions and combustion systems, to avoid storage and transportation safety risks in all directions.
The evaporation loss of liquid hydrogen cannot be completely eliminated, but the surface area to volume ratio of large spherical storage tanks is smaller, the insulation effect is better, and the average daily loss can be controlled below 0.1%. With the active refrigeration system, near zero loss storage can be achieved.
Road transport: Using vacuum insulated cryogenic liquid hydrogen semi-trailer, the carrying capacity of a single vehicle can reach 3-5 tons, suitable for short-and medium-distance regional distribution from liquefaction plant to hydrogenation station and industrial park.
Railway transportation: Relying on large-scale low-temperature railway tankers, it can realize large-scale and long-distance land hydrogen energy transmission, which is suitable for cross-provincial and large-scale hydrogen energy allocation.
Shipping by Sea: Special liquid hydrogen transport ships are the core carrier of cross-border hydrogen energy trade. Australia, Japan and other countries have completed maritime demonstration projects, verifying the feasibility of ocean LH2 transportation.
Space special storage and transportation: Lightweight and highly insulated liquid hydrogen storage tanks are specially designed for space scenarios and can be adapted to extreme environments to provide a stable supply of LH2 fuel for rocket launches and space equipment.
Liquid hydrogen is not a simple energy storage device, but a complete set of “electricity-hydrogen energy-energy utilization” conversion system, which is the core solution of new energy consumption and long-term energy storage.
Although the round-trip efficiency of the whole system is only 30%-50%, which is lower than that of lithium batteries, it perfectly makes up for the short board of short-term energy storage and is one of the most mature seasonal long-term energy storage schemes at present.
When supporting low-cost renewable power, large-scale liquefaction equipment, high value-added industrial application scenarios, the economic value and environmental value of LH2 energy storage will be greatly increased, becoming an important supplementary support for the new power system.
Aerospace field: liquid hydrogen is the most mature and high-end application scenario in aerospace. The combination of liquid hydrogen and liquid oxygen can provide ultra-high specific impulse power, is the mainstream propellant for space launch, and is widely used in space shuttles, launch vehicles, and commercial space launch projects.
Heavy zero carbon transportation: Hydrogen fuel cell heavy trucks, ships, locomotives, aviation prototypes are all suitable for LH2 energy supply. LH2 in the field of transportation can support heavy cards more than 1000 kilometers of long range, to solve the battery vehicle load is low, short range of pain points.
High-end industrial production: High-purity liquid hydrogen supply oil refining, metallurgy, electronic semiconductors and other industries with hydrogen demand, while the recovery of liquefied cold energy, to achieve comprehensive utilization of energy.
Global green energy trade: In the international zero-carbon energy trade, liquid hydrogen is the core carrier of pure hydrogen cross-border circulation. As a zero-carbon commodity that can circulate across borders, liquid hydrogen realizes the global allocation of new energy resources and helps the value of green electricity and green hydrogen in energy-rich areas to land.
The liquid hydrogen industry chain covers the whole process of energy input, hydrogen production, purification, liquefaction, storage and transportation, and terminal application, forming a closed-loop green energy industry system.
Technical level: Ultra-low temperature environment can easily lead to cold brittleness and deformation of materials, and the requirements for equipment materials are extremely high. At the same time, hydrogen molecules are extremely small, prone to leakage, and the precise control of evaporation loss is difficult.
High cost of energy consumption: The problem of high energy consumption in the hydrogen liquefaction link has not been completely solved, and nearly half of the hydrogen energy is lost in the liquefaction process, which increases the overall use cost of liquid hydrogen. With the increase of LH2 production capacity, equipment utilization rate, overlay low-cost green electricity popularization, liquid hydrogen production and operation and maintenance costs will continue to decline, commercial advantages gradually highlighted.
Inadequate safety standards: Hydrogen flammable explosion range is wide, low temperature operation threshold is high. At present, the world has not yet formed a unified LH2 storage and transportation, operation, safety control standards, restricting large-scale promotion.
In response to the demand for large-scale hydrogen energy storage and transportation, Fullcryo has built a complete liquid hydrogen cryogenic equipment solution around “hydrogen liquefaction-cryogenic storage-liquid hydrogen transportation”, covering key links such as hydrogen liquefaction equipment, LH2 storage tanks, liquid hydrogen Dewar and liquid hydrogen semi-trailer, providing cryogenic engineering equipment support from production to storage and transportation for liquid hydrogen projects.
Fullcryo large-scale hydrogen liquefaction plant adopts key technologies such as hydrogen Claude refrigeration cycle, high-speed and heavy-duty hydrogen turbine expander, high-efficiency hydrogen conversion and heat exchange integration, large horizontal vacuum insulated cold box, etc., which can be provided according to project requirements. 5-100 T/D hydrogen liquefaction plant. The system is suitable for large-scale LH2 production scenarios, and the purity of hydrogen raw materials can reach 99.9999%, the parahydrogen content can reach 95% to provide a stable source of liquid hydrogen for subsequent liquid hydrogen storage, transportation and end-use applications.
In the liquid hydrogen storage segment, the Fullcryo provides fixed LH2 storage tanks and low-temperature storage equipment such as liquid hydrogen Dewar. Company independent research and development 100 m grade zero evaporation liquid hydrogen storage tank combined with small cryogenic refrigerator technology, it can reduce the evaporation loss of hydrogen during long-term storage and meet the application scenarios with high requirements for long-term storage and low evaporation rate.
LH2 Dewar reduces heat leakage and evaporation rate of liquid hydrogen through low-temperature technologies such as high-efficiency vacuum insulation, steam cooling multi-cooling screen, low-temperature condensation adsorption, etc. The equipment adopts all stainless steel structure, and is equipped with bellows sealed release valve, pressure valve, isolation valve and reliable safety pressure relief device, taking into account low heat leakage, compact structure and safe operation, can be used for LH2 storage, transportation and distribution.
Fullcryo also provide liquid hydrogen mobile storage and transportation solutions for the medium and long distance transportation needs of liquid hydrogen. its 40 m grade liquid hydrogen mobile storage tank using vacuum insulation and low-temperature storage technology, the design is optimized for on-board transportation scenarios to meet specific operating conditions. 7 days/1000km transportation needs, and to reduce the hydrogen evaporation emissions during transportation as the goal.
Through the systematic configuration of hydrogen liquefaction equipment, liquid hydrogen storage tanks, liquid hydrogen dewar and LH2 semi-trailer, the Fullcryo can cover the key low-temperature equipment links from production, storage to transportation of liquid hydrogen, and provide integrated low-temperature engineering solutions for large-scale hydrogen energy projects, industrial gas supply, clean energy and long-distance hydrogen energy transportation.
There are no absolute advantages and disadvantages of the two technologies, depending on the application scenario. Small-scale, short-distance, high-frequency vehicle scenarios, high-pressure gaseous hydrogen is cheaper and easier to operate. In large-scale, long-distance, long-term energy storage scenarios, LH2 has more advantages.
You can. Liquid hydrogen energy storage can completely accommodate the surplus new energy power that the power grid cannot carry, convert intermittent electric energy into stable hydrogen energy chemical energy storage, and maximize the utilization rate of new energy.
The core barriers focus on the three dimensions of high liquefaction energy consumption, high cost of equipment in the whole industry chain and storage gasification loss.
Losses exist objectively at this stage, but can be reduced continuously through technology and scale optimization in the future.
The volume of hydrogen is greatly reduced after liquefaction, which is more suitable for large-scale storage and long-distance transportation, especially for projects with high requirements for transportation space and storage capacity.
Large-scale hydrogen liquefaction systems usually include hydrogen compression, heat exchangers, turbo-expanders, positive-secondary hydrogen conversion devices, cryogenic cold boxes and control systems.
Fullcryo can provide 5-100 T/D level hydrogen liquefaction units, which can be designed according to the project scale and process requirements.
BOG(Boil-Off Gas) is hydrogen formed by partial vaporization of liquid hydrogen under the influence of ambient heat, which needs to be managed by pressure control, recovery or reliquefaction.
The transportation distance depends on the tank capacity, insulation performance, transportation method and BOG control capability. Liquid hydrogen can be transported by liquid hydrogen semi-trailer, rail or sea.
Liquid hydrogen Dewar is suitable for LH2 storage, short-distance transportation, filling and terminal distribution, especially for small and medium-sized liquid hydrogen use needs.
Under the background of global double carbon transformation and large-scale development of new energy, LH2 is the core solution for large-scale storage, long-distance transportation and cross-seasonal energy storage of hydrogen energy. Compared with traditional high-pressure hydrogen storage, liquid hydrogen with ultra-high volume density and storage and transportation efficiency, more suitable for bulk hydrogen energy circulation and large-scale new energy storage scenarios, is the key carrier of hydrogen energy industrialization and globalization. Although the current LH2 has the problems of high liquefaction energy consumption, high upfront cost and high technical threshold, its comprehensive economy will continue to improve with the iteration of technology and industrial scale.
In the future, liquid hydrogen will be deeply integrated into the new power system and the global energy trade system, and become the core green energy carrier supporting new energy consumption, zero-carbon industrial upgrading and cross-regional energy allocation.
