For emerging industries, independent and controllable core technologies are the cornerstone of high-quality development.

　　China's hydrogen energy industry is in its infancy, and the storage and transportation links are one of the current bottlenecks restricting the development of hydrogen energy in China.

　　Because hydrogen has low density, flammability, and explosiveness, the safe and efficient transportation and storage of hydrogen energy is difficult, which also leads to high costs in the hydrogen storage and transportation sector.

　　Storage and transportation support hydrogen production and downstream applications such as hydrogen fuel cell vehicles. Safe and efficient hydrogen transportation technology is a prerequisite for the large-scale commercial development of hydrogen energy.

　　Institutions generally expect that the hydrogen storage and transportation sector alone has the potential to constitute a market of hundreds of billions of yuan, and 30% of the future terminal hydrogen price will be used for storage and transportation costs.

　　Among all hydrogen transportation schemes, pipeline transportation is the most economical method. Utilizing existing natural gas pipelines for hydrogen blending and constructing new pure hydrogen pipelines for hydrogen transportation are of great significance to the development of hydrogen storage and transportation.

　　On April 10, the "West Hydrogen East Transmission" hydrogen pipeline demonstration project was included in the "National One-Network" Construction Implementation Plan for Petroleum and Natural Gas, marking the official launch of China's long-distance hydrogen transportation pipeline project.

　　The planned "West Hydrogen East Transmission" pipeline passes through nine counties in three provinces (municipalities) including Inner Mongolia, Hebei, and Beijing. The pipeline is more than 400 kilometers long, with an initial capacity of 100,000 tons/year and a reserved potential for future expansion to 500,000 tons/year. It is China's first cross-provincial, large-scale, long-distance pure hydrogen transportation pipeline, which can alleviate the problem of green hydrogen supply and demand mismatch in China.

　　On April 16, a breakthrough was achieved in the long-distance hydrogen transportation technology of the natural gas pipeline (397 kilometers long) in Ningxia Ningde. The hydrogen proportion gradually reached 24%, and the overall operation was stable.

　　Currently, the market demand for hydrogen energy is growing rapidly. The breakthroughs in hydrogen blending technology and long-distance hydrogen transportation technology mean that China's hydrogen transportation pipelines are expected to be commercially promoted.

　　01

　　Pipelines are the best route for long-distance transportation of hydrogen.

　　The technical routes for storage and transportation generally include three methods: gaseous storage and transportation, liquid storage and transportation, and solid storage and transportation.

　　However, compared with traditional fossil fuels such as petroleum and natural gas, hydrogen has inherent disadvantages in storage and transportation, and its development progress has been slow.

　　Readers who have studied high school chemistry know that hydrogen is the first element in the periodic table. Hydrogen has a small mass and low density. Its properties are very active, and it is both easy to leak and easy to explode.

　　For such a gas, storage and transportation are obviously very troublesome. Even if no danger occurs, it will cause a considerable degree of uneconomical cost.

　　We can simply understand this through an example—transporting a truckload of hydrogen, the weight of the cylinders is more than 95%, and only 5% is the required hydrogen, and it cannot be transported over long distances, so this is an unprofitable business.

　　The economical transportation radius of gaseous hydrogen is limited to within 200 kilometers. Within 50 kilometers, the transportation cost of hydrogen is more than 4 yuan per kilogram, 100 kilometers is more than 8 yuan, and the transportation cost reaches 20.18 yuan/kg at a distance of 500 kilometers.

　　Moreover, each torpedo truck transporting compressed hydrogen can only carry 300 kg.

　　Undoubtedly, the problems of cost and load undoubtedly restrict the long-distance transportation of hydrogen and hinder the development of the hydrogen energy industry.

　　From the perspective of technical routes, for medium and long-distance large-scale transportation, pipeline and liquid hydrogen transportation methods are mainly considered. Liquid storage and transportation have a higher hydrogen storage density, but the equipment investment and energy consumption costs are higher. Pipeline transportation is undoubtedly the best solution.

　　Institutions analyze that when the transportation distance is 100 kilometers, the hydrogen transportation cost is 1.43 yuan/kilogram. Under the same transportation distance, the pipeline hydrogen transportation cost is lower than that of high-pressure long-tube trailers and low-temperature liquid hydrogen transportation.

　　By the end of 2022, the total mileage of oil and gas pipelines in China reached 185,000 kilometers. Based on China's current natural gas consumption, when the hydrogen blending ratio reaches 20%, more than 10 million tons of hydrogen can be transported, equivalent to more than 560 billion kilowatt-hours of green electricity, and the cost of hydrogen will also decrease significantly.

　　02

　　Pipeline transportation relies on natural gas blending as a transition.

　　Although pipeline transportation has advantages such as large hydrogen transportation volume, low energy consumption, and low cost, the initial investment cost of pipeline construction is relatively large.

　　The cost of long-distance hydrogen pipelines is approximately US$630,000/km, while the cost of natural gas pipelines is approximately US$250,000/km. The cost of hydrogen pipelines is approximately 2.5 times that of natural gas pipelines.

　　Currently, hydrogen applications and hydrogen refueling stations have not yet been widely popularized, and hydrogen refueling stations are relatively scattered, limiting the economic efficiency of pipeline transportation.

　　On the other hand, affected by differences in gas properties, hydrogen blending ratio, pipeline materials, and external environment, hydrogen is prone to risks such as hydrogen embrittlement, penetration, and leakage after entering the pipeline.

　　Studies have shown that hydrogen pressure, purity, environmental temperature, pipeline strength level, deformation rate, and microstructure all affect the degree of pipeline damage.

　　Therefore, from the perspective of cost and technology, at present, it is not the time to massively build dedicated hydrogen transportation pipelines. Pipeline hydrogen transportation mainly adopts the method of natural gas blending.

　　Natural gas blending is to inject a certain proportion of hydrogen into natural gas to form a mixed gas (HCNG), and transport the hydrogen-blended natural gas to end users through natural gas pipelines, and then directly use it or purify the hydrogen for separate use.

　　Currently, there are no internationally established standards and specifications for hydrogen-blended natural gas pipeline transportation systems, and the maximum allowable hydrogen blending ratio in national natural gas quality standards varies. For example, the upper limit of hydrogen blending in Germany's natural gas distribution system is 10%, France is 6%, Italy is 5%, and Australia is 4%.

　　Studies have shown that theoretically, natural gas-hydrogen mixed fuel containing 20% by volume of hydrogen can directly use current natural gas transportation pipelines without any modification.

　　Blending 20% hydrogen into natural gas can increase engine thermal efficiency by 15%, improve economy by 8%, and reduce pollutant emissions by 60% to 80%.

　　Hydrogen pipelines have the potential for large-scale hydrogen transportation, offering significant cost and efficiency advantages. Against the backdrop of carbon neutrality, governments worldwide are vigorously promoting natural gas blending projects as a way to explore hydrogen energy applications, and the "trend" of natural gas blending has swept the globe.

　　03

　　A Global Wave of Pipeline Transportation Planning

　　Statistics show that globally, hydrogen transmission pipelines exceed 5,000 km, primarily operated by hydrogen producers. The United States leads with over 2,700 km of hydrogen pipelines, followed by Europe with 1,770 km.

　　The United States is at the forefront of pipeline hydrogen technology, with maximum operating pressures reaching 10.3 MPa, mainly along the Gulf Coast, with approximately 1,000 km of pipelines.

　　Looking ahead, the global development of hydrogen pipelines is accelerating.

　　In July 2020, Europe proposed the European Hydrogen Backbone, a plan that currently involves 31 natural gas infrastructure companies across 28 countries and regions.

　　It is expected that five pan-European hydrogen supply and import corridors and nearly 28,000 km of hydrogen pipelines will be completed by 2030, and a hydrogen transmission pipeline network of approximately 53,000 km will be established by 2040. Further growth is expected. The estimated total investment is €800-1430 billion.

　　For land-based pipeline transportation, the average transportation cost per kilogram of hydrogen per 1,000 km is €0.11-0.21. If hydrogen is transported solely via submarine pipelines, the average cost per kilogram per 1,000 km is €0.17-0.32.

　　China's current pipeline length lags behind developed countries, with slower construction progress. The total domestic mileage is currently only 400 km, with only about 100 km of pipelines in use.

　　In 2022, the National Development and Reform Commission and the National Energy Administration jointly issued the "Medium and Long-Term Plan for the Development of the Hydrogen Energy Industry (2021-2035)", proposing pilot projects for blended hydrogen natural gas pipelines and pure hydrogen pipelines.

　　With policy support, hydrogen pipelines are experiencing a period of rapid development. In recent years, China has seen continuous progress in hydrogen pipeline construction, accelerating domestic development.

　　Institutions predict that as pipeline capacity utilization decreases, transportation costs will increase significantly, while higher utilization rates will result in relatively lower costs.

　　For example, with 100% pipeline capacity utilization, increasing the transportation distance from 50 km to 500 km only increases the transportation cost from 0.8 yuan/kg to 2.3 yuan/kg, significantly lower than the transportation costs of gas hydrogen trailers and liquid hydrogen.

　　After the widespread adoption of hydrogen energy in various fields, pipeline hydrogen transportation will become the most promising method.

　　At the same time, hydrogen pipeline transportation faces numerous technological challenges in the future.

　　For example, low-cost, high-strength hydrogen embrittlement resistant materials, and high-performance hydrogen pipeline design and manufacturing technologies. Domestication of core equipment, such as high-flow compressors, hydrogen metering equipment, valves, and instruments. Also, the establishment of a corresponding hydrogen pipeline standard system, covering design, construction, operation, and maintenance.

　　With policy support and market demand, China's pipeline hydrogen technology is developing rapidly.

　　The current natural gas hydrogen blending ratio is generally between 2% and 20%, with 20% being a theoretical laboratory value. However, the natural gas pipeline in Ningxia Ningde, China (397 km long), has gradually reached a hydrogen ratio of 24%, with stable overall operation.

　　With the development of the hydrogen energy industry, the domestication of core key equipment is progressing rapidly, and the technology iteration and cost-effectiveness of domestic brands are improving quickly.

　　In addition, China has made some breakthroughs in relevant standards for pipeline hydrogen transportation:

　　In July 2021, the compilation of the "Engineering Technical Regulations for Urban Civil Hydrogen Transmission and Distribution Systems," led by Southwest Municipal Engineering Institute, officially commenced.

　　At the same time, the China Standardization Association approved the compilation of the "Technical Regulations for Industrial Pipelines for Hydrogen Transportation" and issued the "Notice on Public Solicitation of Opinions on the China Standardization Association Standard ".

　　With technological breakthroughs, domestic substitution of core equipment, and the establishment of a domestic pipeline hydrogen transportation standard system, China's pipeline hydrogen transportation industry is poised for rapid development.

　　By 2030, the hydrogen energy industry will become a new economic growth point and an important component of China's new energy strategy, with the construction mileage of hydrogen pipelines reaching 3,000 km.

　　Hydrogen pipelines will help China's development in renewable energy hydrogen production, hydrogen storage, hydrogen chemical industry, hydrogen transportation, and hydrogen metallurgy, promoting further market application of the hydrogen energy industry and contributing to the achievement of carbon neutrality goals.