3D visualization of a new direct reduction plant - Source: thyssenkrupp Steel Europe AG
Politicians and the economy are longing for increased hydrogen use and have long since embarked on a search for solutions. Not only must the production and storage of H2 be ensured, but also its transport must be regulated so that the hydrogen reaches the point of use from the place of production. However, there is a high investment requirement for hydrogen storage and transport routes. The pipe industry, which already offers suitable technologies and materials, is in demand. So there's a lot in the pipeline…
Europe plans to be carbon neutral by 2050. Hydrogen will be co-decisive in achieving climate neutrality – in several respects. As a storage medium, it can be used to compensate for the fluctuations between energy production and consumption that occur when renewable energies are used. In addition, the use of green hydrogen makes the industry – such as in steel production – CO₂-neutral. An infrastructure consisting of pipelines and plant technology is necessary.
Safe hydrogen transport will play a central role in a renewable energy mix – and the pipe industry is already H2-ready. Mannesmann supplies steel pipes that are designed for transport and storage. For H2 forwarding – for example in pipelines – the inner surface is manufactured free of surface deposits. Internal attack points for hydrogen are kept to a minimum by falling below the phosphorus and sulphur content – compared to the EIGA Directive. “A further lowered carbon equivalent ensures excellent weldability of our pipe material,” Mannesmann stresses. This ensures long service life.
Pipe industry ready for the H2 market Together with partners from the steel distribution sector, Benteler Steel/Tube supplies the Benteler Hyresist product family, which includes seamless, hot-rolled pipes and meets the requirements of the European Industrial Gases Association (EIGA) for pipes for distribution networks. The criteria are: hydrogen-compliant steel analysis, pressure resistance and homogeneous structure. With an outer diameter of 21.3 to 141.3 mm, the dimension range of the Benteler pipe solution corresponds to the current specifications for hydrogen pipes. “In addition, optimised mechanical values and the high purity of the steel materials used, prevent hydrogen embrittlement,” the company explains.
Butting is also ready for the H2 pipe market. According to the company, vacuum-insulated transfer lines could save time and resources compared to conventionally foam-insulated pipes. The cost-efficient transfer of liquid natural gas and liquid hydrogen LH2 (LNG) requires pipeline systems in much larger dimensions than other cryogenic liquids. Thus, smaller pipe diameters can be selected, whereby the material expenditure is reduced. In addition to standard lines, the company's expertise includes transfer systems for trailers (helium and hydrogen), hydrogen systems for the automotive industry and refuelling systems for the aerospace industry (hydrogen and oxygen).
Major Hydrogen Projects It is important to act with foresight. Thus, in Wolfsburg, two state-of-the-art gas-fired power plants will secure the energy supply of the VW plant and the city of Wolfsburg. “Mannesmann H2ready® pipes from Mannesmann Line Pipe have already been used in the construction of the supply line so that they can also be operated with hydrogen in the future,” explains Mannesmann. The nearly 1,900 tubes have individual lengths of up to 18 metres in L360NE quality and, in the main, a diameter of 406.4 mm. The route runs parallel to an already existing line and has been laid over a length of nine kilometres without a trench and thus particularly gently. For this purpose, the pipes were additionally wrapped with GRP (glass-reinforced plastic).
For the connection of the LNG gas terminal from Brunsbüttel to Hetlingen, Mannesmann Grossrohr GmbH (MGR), a subsidiary of Salzgitter AG, supplies pipes with a diameter of DN 800 for a total length of about 54 kilometres on behalf of Gasunie Deutschland. The approximately 3,200 pipes are specified “so that hydrogen can also be transported through the line in the future,” explains MGR. It is scheduled to come into operation by the end of 2023.
A currently eye-catching construction project is the connection of the LNG terminal Wilhelmshaven with H2-ready steel pipes from Mannesmann Line Pipe on behalf of the energy grid operator Ewe Netz. With around 16,000 tons of H2-ready pipes, Mannesmann is contributing to the expansion of the LNG infrastructure in Northwest Germany. In total, the company supplies about 4,100 pipes in the dimension range DN 600 in lengths of 18 to 12 meters. The commissioning of the line is to take place at the end of 2023.
More Climate-Friendly Steel Production For the production of pipes for hydrogen transport, H2-optimized steels are required for safe and durable pipeline transport systems, which Thyssenkrupp also supplies. In addition to the low-alloy steel grades X42 and X52, which are suitable for the transport of gaseous hydrogen and hydrogen mixtures, the Group has optimised material concepts for the strength range up to X70. “These steels are optimised with regard to the expected standard requirements of longitudinal and spiral seam tubes for hydrogen transport, in particular for the limited contents of carbon, phosphorus and sulphur,” explains Thyssenkrupp.
The production of steel – with the help of hydrogen – should also become more climate-friendly. Thyssenkrupp Steel is therefore investing in the decarbonisation of its steel production, which in turn improves the ecological balance of steel pipes. The Group therefore commissioned SMS with the engineering, supply and construction of a hydrogen-powered direct reduction plant, two smelters and associated ancillary units at the Duisburg site. It is one of the world's largest industrial decarbonisation projects with an order volume of more than 1.8 billion euros for SMS alone, with commissioning scheduled for the end of 2026.
Building H2 Infrastructure With SALCOS® (Salzgitter Low CO2 Steelmaking), Salzgitter, together with partners from business and research, is striving to lay the foundations for steel production that is almost CO2-free. Central elements of the program are electricity from renewable sources and its use in the production of hydrogen by electrolysis. “This green hydrogen will replace the coal we are currently using in the conventional blast furnace process,” the Group explains. This is made possible by means of so-called direct reduction plants, in which iron ore is reduced to iron in the solid state directly by hydrogen. With this technology, instead of CO₂, water vapour is emitted.
There is a lot to do: For example, Germany is not sufficiently prepared for the ramp-up of the hydrogen economy. This is the result of the H2 balance sheet, an analysis by the energy group E.ON, which is based on data from the Institute of Energy Economics at the University of Cologne. “Looking ahead to 2030, it turns out that neither the domestic generation capacity of green hydrogen is sufficient nor can German import needs be met.“ There is also a lack of infrastructure – still. Now the pipe industry is also required here. It is ready for implementation.
Innovations in these fields will be presented at Tube Düsseldorf from 15 – 19 April 2024 at Düsseldorf Fairgrounds.