Pipeline hydrogen transportation refers to the method of transporting hydrogen gas through pipelines. It is an efficient and economical method of hydrogen transportation, particularly suitable for large-scale, long-term hydrogen supply and distribution. Due to the flammable, explosive, and highly permeable nature of hydrogen, pipeline hydrogen transportation requires special attention to safety and material selection.

　　What is pipeline hydrogen transportation?

　　Pipeline hydrogen transportation refers to a method of transporting hydrogen gas through a specially designed pipeline system. It is mainly used to transport hydrogen from production sites to storage or usage sites, such as industrial users, hydrogen refueling stations, or other places with hydrogen demands. Pipeline hydrogen transportation usually involves the long-distance transportation of high-pressure hydrogen, ensuring that the hydrogen can be transported safely and economically.

　　This transportation method is typically used in large-scale industrial applications and is also considered part of the future infrastructure for building hydrogen supply, supporting the development of a hydrogen energy economy.

　　Advantages of Pipeline Hydrogen Transportation

　　As an efficient and economical method of hydrogen transportation, pipeline hydrogen transportation has broad application prospects in the future hydrogen energy society. Its advantages are mainly in the following aspects.

　　Cost Advantages

　　Pipeline hydrogen transportation has significant advantages over other hydrogen transportation methods (such as liquid hydrogen transportation and compressed hydrogen tanker transportation), especially in large-scale, long-distance hydrogen transportation. First, pipeline hydrogen transportation can achieve continuous and stable hydrogen supply, avoiding interruptions and storage bottlenecks caused by frequent transportation. Second, pipeline hydrogen transportation is more economical in the long run. Although the initial construction cost is high, the operating cost is low in large-scale applications, especially in areas with fixed demand.

　　Large-Scale Transportation Capacity

　　Pipeline hydrogen transportation can meet large-scale hydrogen demands, especially in areas with widespread hydrogen applications, such as industrial production, urban hydrogen supply networks, and hydrogen refueling stations, providing a large amount of hydrogen continuously and stably.

　　High Efficiency and Economy

　　Compared with other transportation methods (such as liquid hydrogen tankers and compressed hydrogen transport vehicles), pipeline hydrogen transportation has lower costs for large-scale and long-distance transportation, especially in scenarios with stable and continuous demand, saving hydrogen transportation costs and operating expenses.

　　Improved Safety

　　Transporting hydrogen through pipelines can reduce risks during transportation, such as potential traffic accidents and leaks during liquid hydrogen tanker transportation or compressed hydrogen storage and transportation. The pipeline system itself is strictly designed and can be equipped with leak detection devices, automatic shut-off valves, and other safety equipment.

　　Continuous Supply

　　Pipeline hydrogen transportation has the ability to supply continuously and in real-time, avoiding supply interruptions caused by other transportation methods. This is especially important in situations requiring stable and continuous supply, such as industrial hydrogen applications and fuel cell power plants.

　　Types of Pipeline Hydrogen Transportation

　　Long-distance pipelines are mainly used to connect hydrogen production plants with hydrogen stations, responsible for high-pressure, large-diameter hydrogen transportation. Short-distance pipelines are used for hydrogen distribution between hydrogen stations and end-users, with lower hydrogen transportation pressure and relatively smaller pipe diameters.

　　According to the different hydrogen purities, pipeline hydrogen transportation can be divided into two methods: natural gas blended hydrogen transportation and pure hydrogen transportation.

　　Natural gas blended hydrogen transportation is a technology that mixes "green hydrogen" produced from renewable energy sources with natural gas and transports it to the user terminal through existing natural gas pipelines. Its technical feasibility mainly depends on the physical properties of the natural gas after hydrogen blending, the tolerance of the pipeline material, and the adaptability of the equipment during transportation.

　　Pure hydrogen transportation is an efficient and economical method for large-scale, long-distance hydrogen transportation, but it has high construction difficulty and high cost. Usually, the cost of a long-distance hydrogen pipeline is 2 to 3 times that of a natural gas pipeline.

　　According to the form of hydrogen transportation, it can be divided into two types: gaseous transportation and liquid transportation.

　　Material Applications

　　The material selection for pipeline hydrogen transportation is crucial because hydrogen has unique physical and chemical properties, such as small molecules, high diffusivity, flammability, and embrittlement of certain metals (hydrogen embrittlement). Therefore, the materials must meet the requirements of safety, durability, and economy. The following are commonly used pipeline hydrogen transportation materials and their characteristics:

　　Stainless Steel (Austenitic Stainless Steel, such as 304, 316L)

　　Characteristics: Stainless steel has excellent corrosion resistance and hydrogen embrittlement resistance, especially austenitic stainless steel (such as 304, 316L) performs well in a hydrogen environment and is suitable for high-pressure hydrogen transportation.

　　Composite Materials (Carbon Fiber Reinforced Composites)

　　Characteristics: Composite materials have the advantages of high strength and lightweight, especially carbon fiber reinforced composites, which exhibit excellent pressure resistance and hydrogen embrittlement resistance in hydrogen transportation. This material has significant advantages in weight, strength, and durability.

　　The selection of pipeline hydrogen transportation materials needs to comprehensively consider factors such as hydrogen pressure, transportation distance, material cost, hydrogen embrittlement resistance, and environmental conditions. High-pressure systems usually use stainless steel, nickel-based alloys, and other materials, while low-pressure systems can use carbon steel, polymers, or composite materials.