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  • HydrOxy Hub Walsum

    A hydrogen lighthouse project in Duisburg for the decarbonization of the steel industry

    Together with the project partners thyssenkrupp Steel and thyssenkrupp Uhde Chlorine Engineers, STEAG is working on a feasibility study for the construction of a water electrolysis plant with a capacity of up to 500 megawatts (MW) on the site of the STEAG site in Duisburg-Walsum. The plant will supply green hydrogen and oxygen to the nearby steel mill of thyssenkrupp Steel. If an investment decision is made in spring 2023, commercial operation of the plant is conceivable in early 2025.


    We can imagine that the project raises one question or another, and hope we have answered the most important questions for you below.

    • Which parties are involved in the project and what functions will they then take on?

      The project is supported by two member companies of the thyssenkrupp Group and STEAG. These are the following companies:

      • STEAG Green Business GmbH (STEAG) (operation and production)
      • thyssenkrupp Steel Europe AG (tkSE) (hydrogen offtaking and deployment in steel production)
      • thyssenkrupp Uhde Chlorine Engineers GmbH (tkUCE) (plant supplier)
    • How much will the three companies invest?

      On the basis of current estimates, the project volume is expected to be up to EUR 500 million with an electrolysis capacity of 500 megawatts (MW). All three project partners are planning their own participation as investors and will also raise targeted private and public funding and subsidies. It is therefore not yet possible to provide an exact figure for the individual investments, as this also depends on the other funding providers and the development of the project.

    • What is to be the capacity of the electrolysis system?

      The construction and operation of an electrolysis plant with a capacity of up to 500 MW would be possible on the STEAG site in Walsum. This corresponds to a hydrogen production of approx. 9 t/h and an oxygen production of approx. 72 t/h. The exact capacity at the start of the project will be determined in the course of the feasibility study or during project development. The hydrogen in particular will enable thyssenkrupp to produce steel in a climate-neutral way at the Duisburg site in the future.

    • When would the electrolysis plant go into operation?

      Commissioning is planned for the start of 2025, provided that a decision on investments is made in spring 2023.

    • Where exactly is the electrolysis plant to be built?

      The electrolysis plant is to be built at the STEAG site in Walsum on the site of the former coal mine west of Römerstrasse. This location is ideally suited, not least because of its proximity to the steelworks site.

    • How does electrolysis function, and what exactly is it needed for?

      The basic principle of water electrolysis is the splitting of water into hydrogen and oxygen by means of electric current. If electricity from renewable energy sources is used for this purpose, the result is what is known as green hydrogen – “green” because it was produced in a climate-neutral way. In addition to hydrogen and oxygen, heat is also produced, and that can be reused, for example for heating purposes.

      Green hydrogen plays a central role, for example, in the decarbonization of the steel industry. There, it can replace the carbon previously used in the form of coke or coal. The use of carbon in steel production produces CO2, whereas the use of hydrogen produces only steam. Hydrogen takes on the role of a reducing agent with which iron ore (in the form of iron oxides) is reduced. In concrete terms, this means that the oxygen contained in the iron ore is removed. The iron thus obtained is then processed into steel.

      The water electrolysis technology developed by thyssenkrupp Uhde Chlorine Engineers is based on prefabricated standard modules. Thanks to this modular concept, the plant in Walsum can be easily scaled up to several hundred megawatts. This makes it particularly interesting for industrial-scale decarbonization.

    • Where exactly is the pipeline between the electrolysis plant and the steelworks to run? Is it to be buried or above ground?

      There are in fact two pipelines: one for hydrogen and the other for oxygen. The two are to run in parallel to connect the future electrolysis plant in Walsum with the steelworks in Hamborn. The two sites are only a little more than two kilometers apart. The exact route of the pipeline has not yet been determined. The current plan is for it to be laid underground. More concrete details of the execution and initial planning considerations will be provided in the course of the feasibility study. In any case, however, it will be ensured that the route planning will be coordinated both with the planned bypass road to reduce traffic in the center of Walsum and with the further development of the Logport site.

    • Is noise to be expected from the electrolysis plant?

      An electrolysis plant, even of this size, works at very low noise levels. Only the fans, compressors, cooling systems and the like which may be required can constitute relatively small sources of sound. All sound sources will be equipped according to the state of the art in noise reduction technology and the plant will not make any relevant sound contribution to the environment.

      Since the water and oxygen produced will then be conveyed to the steelworks by underground pipeline, the conveying process will not create any noise emissions.

    • Will there be an increase in traffic around the electrolysis plant?

      As the water and oxygen produced are conveyed to the steelworks by pipeline, no additional traffic volume will be created by product transport. Nor will the other operating supplies required for the electrolysis plant (mainly water and electricity) result in any traffic volume. Isolated traffic is to be expected in connection with the delivery of materials, maintenance work and the arrival and departure of employees, visitors, etc.

      It goes without saying that during the construction of the electrolysis plant there will be a temporary increase in traffic for the construction work.

    • Will the electrolysis plant and the connection to the thyssenkrupp works site have an influence on the planned bypass (SW link road) and the associated Friedrich Park project?

      Whatever the final plans for construction of the pipeline may be, it is clear that the requirements of the bypass and the Friedrich Park project will be taken into account. This also appears to involve no complications because the planned bypass is to end at the connection to Dr.-Wilhelm-Roelen-Strasse. There are no longer any plans to use the former coal mine site. Consequently, the electrolysis plant has no influence on the planned bypass or, of course, on the Friedrich-Park project.

    • Are any restrictions or nuisances to be expected by the neighbors during construction of the plant and the pipeline – for instance from construction noise?

      During the construction of the plant and pipeline, temporary effects of the relevant construction site operations on the environment, for example in the form of construction noise or the arrival and departure of construction vehicles and material deliveries, cannot be avoided. As is usual for construction projects of this kind, rest periods and night-time hours would of course also be observed. The stipulations of the “General Administrative Regulations (AVV) on Construction Noise” govern the procedures in this case. A construction period of just under 2 years is to be expected.

    • Does electrolysis cause emissions? Are smoke or steam created by electrolysis?

      During the operation of an electrolysis plant, besides hydrogen and oxygen, only heat is produced, which can be fed into a heating network in the form of waste heat by means of a heat pump or has to be recooled in a honeycomb cooler. This can produce plumes of water vapor. Smoke emissions cannot arise.

    • Are any toxic substances created during electrolysis?

      No. No substances or emissions of any kind which are harmful to health are created during electrolysis.

    • What other facilities apart from the electrolysis plant and the pipelines are needed and are to be constructed?

      In addition to the electrolysis plant, further facilities are to be constructed. These are above all compressors for the water and oxygen, systems for recooling and, if necessary, a heat pump. In addition, facilities for connection to the power grid, e.g. a switchgear or transformer substation are to be built. This is necessary because of the considerable amounts of electricity required for electrolysis.

    • Electrolysis requires large amounts of electricity. Do the high voltages not also constitute hazards?

      The electrolysis plant will be operated by STEAG, an energy company that has many years of extensive experience in the safe handling of energy. Against this background, handling the required currents or voltages does not present any challenges in the surrounding area beyond those of today.

    • Where does the electricity for electrolysis come from? Will you be using green electricity?

      The use of hydrogen only becomes truly climate-neutral when it has also been produced in a climate-neutral way – i.e. with green electricity. Accordingly, securing the green electricity supply is an important part of the project. After all, the objective is clearly to produce and supply the steelworks with green hydrogen. STEAG ensures that the energy used comes from renewable sources. This does not mean that the required amount of electricity from renewables has to be generated at the site itself, but rather that STEAG procures the necessary amount and feeds it to the electrolyzer. In addition, STEAG is considering installing PV systems on the roof surfaces of the planned electrolysis buildings, which in turn can supply locally generated green electricity for the production of green hydrogen.

    • Electrolysis requires a lot of water. Are you going to take that from the Rhine? What effects would that have on the river?

      The precise plan will be worked out during the feasibility study. One possibility is to supply the electrolysis plant with water from the public water supply. Alternatively, water from the Rhine could also be treated and used. In this case, the water withdrawal for the electrolysis plant is small compared to the previous water withdrawal at the power plant site. In this respect, there are no effects on the water management in the Rhine.

    • Will the electrolysis process have an effect on the water quality in the Rhine? Will you discharge waste water into the river?

      The electrolysis process does not produce any significant amount of waste water and therefore has no effect on the Rhine or other water courses. However, the production of demineralized water does create waste water, but owing to its harmless composition it can be discharged directly into the Rhine or indirectly into the public sewerage system.

    • What hazards are there for the surroundings of the plant or for areas around the pipeline?

      Incorrect handling of hydrogen does indeed present risks due to the explosive nature of the substance in combination with oxygen. At the same time, however, hydrogen has been a resource used in a variety of ways in industry for decades. The safety technology for handling hydrogen is correspondingly sophisticated and reliable. The safety standards that apply to the operation of the electrolysis plant and the transport of hydrogen are also correspondingly high.

    • The plant is supposed to be very large. What does that mean for the townscape?

      It is planned to erect the plant on the STEAG site, at the site of the former mine to the west of Römerstrasse. A factory-like construction method is being considered, and the plant is most likely to resemble a logistics center on the outside. Compared with the buildings of the existing power plant, the new buildings will not be as high.

    • What area will the plant cover?

      The area required is probably 60,000 - 90,000 m2. The area of the former mine site to the west of Römerstrasse is approx. 150,000 m2. The exact layout plan is still being developed, so a two-story enclosed installation to optimize the footprint is also conceivable.

    • What effect will the impending closure of STEAG’s Walsum 9 power plant have on the project?

      On December 1, 2020, Germany’s Federal Network Agency announced that STEAG’s Walsum 9 power plant unit had been awarded a subsidy as part of the first decommissioning auction for hard coal fired power plants, and will now go off the grid on January 1, 2021. What will happen in the future to the area on which the power plant unit is currently located has not been decided at the present time, and to this extent this part of the site is not the subject of the project considerations regarding hydrogen production at the Walsum site.

    • Would it not be better to construct industrial facilities of this kind further away from residential areas?

      The plants are to be built on land which has traditionally been used for industry. Furthermore, the technology used is suitable for the chosen location and has no impact on the area surrounding the site. Safety standards and safety distances are observed there and the site is operated in accordance with the law on hazardous incidents. In addition, the short distance between the STEAG site in Walsum and the thyssenkrupp Hamborn steelworks allows for short conveying routes and a correspondingly optimum transportation infrastructure. For this reason, and because of the classification of the site under planning law, the project can be implemented quickly. The plant could be commissioned as early as 2025. In addition to these economic advantages, the forward-looking project will secure skilled jobs in the city and region. The former mining site in Walsum will be given a new future within a sustainable hydrogen economy by the project.

    • Will the electrolysis plant create jobs? Do we know how many?

      An electrolysis plant in Walsum would create local jobs for skilled employees and thus strengthen Duisburg as a business location. Due to the increasing importance of hydrogen for various industries and sectors, Walsum offers future-oriented prospects for employees. How many jobs will ultimately be created cannot be determined conclusively at present. In addition, a successful transition to climate-neutral steel production in Duisburg will also secure a large number of jobs for qualified staff.

    • What does the City of Duisburg think of your project?

      All the partners in the project entered into talks with Duisburg city council at an early stage. The project can be a lighthouse project for North Rhine-Westphalia and the city of Duisburg as a hydrogen region. In any case, it is an important step towards the decarbonization of industry and on the way to a climate-neutral society. In this respect, the project contributes to the long-term preservation of Duisburg as a business and industrial location.

    • The plant is to be constructed in the immediate vicinity of residential areas in Duisburg. How is the population to be involved in the process?

      Transparency and the involvement of the neighborhood are important to us. We will therefore seek a dialog with the population of Walsum and provide comprehensive information about the project – for example in the form of question and answer and information events (possibly digitally as a result of the coronavirus). The exchange of information with the city council of Duisburg and the district representatives is also a central focus for us, which is why we sought such an exchange early on. We want to offer new prospects to the Walsum district and the local residents.



    Picture: (C) euroluftbild.de/Hans Blossey