Driven by fuel cell vehicles, on-board high-pressure hydrogen storage cylinders will usher in a period of rapid development in the next decade.
A door is a kind of protection, a layer of concealment, a boundary.
The significance of the action of pushing the door is more profound, representing entering one state and entering another field. This action is integrated into the bits and pieces of our daily lives.
Office workers need to push open the door of the house and push open the door of the company every day. Students are required to enter the school gate every day and push open the classroom door.
In a person's life, it is also necessary to push open the door of many important nodes, such as school, career, family and so on.
Only by mastering the skills can we open smoothly, explore the mysteries of it, and grasp the true meaning of life. On the contrary, the consequences of failing to do so are often inaction, chickens and dogs, and exhaustion.
The secret of success lies in the improvement of cognitive ability, and the accumulation of knowledge is the prerequisite.
In this way, it is only by pushing open multiple doors to spy on the essence of things, accumulating knowledge and improving cognition has become an objective logic.
Following the recent creation of "Pushing open the first heavy door of the trillion hydrogen energy track hydrogen production chapter", now launched a sequel - "Push open the storage and transportation of the second heavy door of the trillion hydrogen energy track".
Key core hydrogen storage bottles
First of all, we still have to return to the industrial chain. Previous, we mainly analyzed the development status of hydrogen production technology and the future technical path, and this article continues to study hydrogen storage and hydrogenation along the industrial chain.
In the subdivision of the industrial chain of hydrogen storage, there is one link that is the most critical. It is a vehicle container in the transportation process, but also a storage equipment for hydrogen refueling stations, hydrogen energy vehicles do not have it, nor can they have fuel reserves.
This link is the hydrogen storage bottle. It can be said that the hydrogen storage cylinder is manufactured with hydrogen on the top, the hydrogen is stored in the middle, and the hydrogen is applied under it.
However, compared with traditional fossil fuels such as oil and natural gas, hydrogen has a natural disadvantage in storage and transportation, and the development progress is slow.
Readers who have studied middle school chemistry are well aware that hydrogen is the number one element in the periodic table, hydrogen has a small mass, low density, and its nature is very active, which is easy to leak and easy to explode.
The construction and strength of the container often depends on the physical and chemical properties of the material being loaded.
For such a gas, storage and transportation is obviously very troublesome, even if there is no danger, it will cause a considerable degree of cost and uneconomical.
We can understand it simply by an example - transporting a truckload of hydrogen, the bottle weight is more than 95%, the hydrogen required is only 5%, and it cannot be transported over long distances. So it's not a good deal.
The key to solving the problem lies in the hydrogen storage bottle as a device. Its technical path needs to face three ways: gas storage and transportation, liquid storage and transportation, and solid state storage and transportation.
Through the exploration of the technical field, a simple comparison of these three methods can roughly lead to some certain conclusions.
The cost of gaseous storage and transportation is low, and the speed of hydrogen filling and discharging is faster, but the hydrogen storage density and transportation radius are relatively limited, so it is suitable for short-distance transportation.
The economic transportation radius of hydrogen gas is limited to 200 kilometers, the cost of hydrogen transportation within 50 kilometers is 2 yuan, the transportation cost of 0-100 kilometers is 4 yuan / kg, and the torpedo car transporting compressed hydrogen can only transport 300kg per vehicle.
In contrast, medium- and long-distance large-scale transportation mainly considers pipeline and liquid hydrogen transportation methods. The hydrogen storage density of liquid storage and transportation is large, but the equipment investment and energy consumption cost are higher; solid state storage and transportation are applied in special fields such as submarines, and the whole is still in the small-scale test stage.
For now, the mainstream mode of hydrogen transportation is still high-pressure gaseous storage. Obviously, the storage and transportation of hydrogen must be filled with more hydrogen in the storage and transportation bottle. This actually points to the path of hydrogen transport – how to increase the unit bulk density of hydrogen.
To transport as much hydrogen as possible, it is necessary to take a greater pressure to load hydrogen into the hydrogen cylinder, the pressure of the on-board high-pressure hydrogen storage cylinder is generally 35 to 70 MPa, the mainland is mainly using 35 MPa at this stage, and 70 MPa has gradually entered the commercial market.
Some investors may be unfamiliar with this magnitude, but it is not difficult to understand.
35MPa is the equivalent of 350 kg of weight level of the player using the golden rooster independent posture only with the big toe as a support, stepping on a place 1 square centimeter to generate force. Or you can imagine that you can use one of your fingers to lift up the Ding that crushed the King of Qin Wu that year.
We are clearly aware of the demanding requirements placed on the compressive strength of the material.
In addition, while withstanding pressure, because the weight of the bottle cannot occupy too much proportion during transportation, it is impossible to make the bottle body thick and heavy, but it is necessary to replace the lightweight material.
Therefore, the technical direction of hydrogen energy bottles is actually very clear: pressure resistance and weight reduction. It requires enterprises to consider from the perspective of hydrogen storage density and lightweight, and improve technology and corresponding materials.
At present, from a technical point of view, the high-pressure gaseous hydrogen storage container is mainly divided into pure steel metal bottle (type I), steel inner tank fiber winding bottle (type II), aluminum inner tank fiber winding bottle (type III) and plastic liner fiber winding bottle (type IV) four levels of products.
Source: DOE
Among the four levels of products, type I and type II product technology were first applied, but limited to material limitations, low hydrogen storage density, heavy quality, and poor safety, unable to work under 35MPa conditions, so it has gradually faded out of the market.
Comparatively speaking, the current mainstream is type III and IV products, due to the inner tank and protective layer of these two types of products, it is more advanced in materials and processes, making the cylinder light in weight, high hydrogen storage density and good safety.
Therefore, from the perspective of application scenarios, type I and type II are mainly used in fixed hydrogen storage such as hydrogen refueling stations, and type III and TYPE IV are mainly used in hydrogen fuel cell vehicles.
Comparing type III and TYPE IV products, there are also technical differences - Type IV uses resin in the inner tank during the production process, and the cost is significantly better than that of Type III using aluminum materials, and under the trend of the future 70MPa standard, the cost reduction effect of Type IV products is more obvious, and its life is longer than type III.
However, although the IV type product is excellent, there are also technical problems - due to the use of resin liner, the safety is greatly reduced, heat resistance, hydrogen penetration, easy to crack, sealing and other problems pose a lot of challenges to the manufacturing process, the development of composite materials.
At present, China's on-board hydrogen storage cylinders are mainly type III (aluminum liner fiber winding), and type IV (plastic liner fiber winding) is still in the research and development stage. The vehicle-mounted hydrogen storage bottle products developed by Japan, the United States and other countries are mostly IV types, and some countries have even begun to develop V-type hydrogen storage bottles, that is, no inner tank fiber winding, in this field, the country is still blank.
Comparatively speaking, it can be concluded that this is a first-come, first-served market competition form - who first masters the core technology of type IV, in the future 100 billion market space will be one step ahead, take the lead in seizing market share and excess revenue, and can also achieve a win-win situation to promote the development of hydrogen energy.
Carbon fiber – the core material of hydrogen storage bottles
The hydrogen storage cylinder industry chain can be simply divided into three links: upstream raw materials and parts, midstream production and manufacturing, and downstream terminal application.
Among them, upstream raw materials include aluminum, steel, carbon fiber and resin, etc., parts include various metal valves and various sensors; midstream production and manufacturing equipment and manufacturing processes; downstream is the application of fuel vehicles, hydrogen transport tanks, hydrogen refueling stations and other scenarios.
From the perspective of the material cost of the on-board hydrogen storage cylinder, the cost of the hydrogen storage cylinder is mainly concentrated in the carbon fiber composite material for external winding. For the cost composition of 35MPa and 70MPa high-pressure hydrogen storage IV bottles with a hydrogen storage quality of 5.6kg, the cost of carbon fiber composite materials accounts for 75% and 78% of the total cost of the system, respectively.
According to the DOE's early cost assessment of the vehicle-mounted high-pressure hydrogen storage cylinder project, it can be found that whether it is 35MPa or 70MPa, in general, the cost of type III high-pressure hydrogen storage cylinders is slightly higher than that of type IV, the main reason is that type III bottle storage tanks use a large amount of metal aluminum material.
In contrast, type IV bottles use lower polymers and less polymers. The transformation of type III bottles to TYPE IV bottles is the future development trend.
Source: DOE
At present, the carbon fiber for high-pressure hydrogen storage cylinders mainly adopts T700 grade and above specifications. From the perspective of corporate carbon fiber manufacturers, Japan and the United States still dominate the current carbon fiber manufacturers.
In terms of basic materials for hydrogen storage containers, tank materials have been localized, but high-performance carbon fiber materials have been monopolized by Japan and the United States; Toray's carbon fiber is the main supplier of global vehicle-mounted hydrogen storage cylinder enterprises, and China's on-board high-pressure hydrogen storage cylinder carbon fiber is basically from Toray.
In terms of hydrogen storage container production process, carbon fiber winding equipment and high-pressure tank processing equipment still need to be imported, and the overall localization rate is about 50%.
After nearly ten years of rapid development of carbon fiber in mainland China, key leading enterprises and units have broken through the dry spray wet spinning technology, realized the autonomy of the core technology and key equipment of T700, T800 and higher carbon fiber, and gradually broadened the application field.
At present, the mainland carbon fiber enterprises are mainly based on the 688295. SH), Hengshen shares, Guangwei Composite (300699.SZ) and other enterprises.
At present, due to the immature preparation technology of domestic 70MPa carbon fiber winding IV type bottles, large-scale production is difficult, so the current cost is relatively high, which inhibits the demand for IV type hydrogen storage bottles.
According to a study by the American Council for Automotive Research, the larger the production scale, the lower the cost of hydrogen storage cylinders. For example, when the production scale of gas cylinders is increased from 10,000 sets to 500,000 sets, the cost of hydrogen cylinders will be reduced by 20%. In the future, with the rapid development of hydrogen energy vehicles, the cost of hydrogen storage cylinders is expected to decline.
In addition, bottle mouth valves, pressure reducing valves, etc. also mainly rely on imports, and these key materials and components will gradually be localized in the future.
According to the "China Hydrogen Energy Industry Development Report 2020" plan, in 2022, 2025 and 2030, the number of hydrogen fuel cell vehicles will be 10,000, 100,000 and 1 million respectively, and hydrogen fuel cell vehicles will be rapidly increased in the field of buses, heavy trucks, logistics vehicles and other models.
Industry insiders pointed out that the cumulative market space of high-pressure hydrogen storage cylinders in 2022, 2025 and 2030 will reach 2 billion, 11.9 billion and 111.84 billion yuan respectively, and the single-year market space from 2026 to 2030 is expected to exceed 20 billion.
Vehicle-mounted high-pressure hydrogen storage bottle is currently a kind of hydrogen storage equipment with relatively mature technology and commercialization among many hydrogen storage equipment. Driven by fuel cell vehicles, on-board high-pressure hydrogen storage cylinders will usher in a period of rapid development in the next decade.