Germany's industry is converting to green hydrogen. Ships are expected to deliver the first quantities in 2025. But for the gas to reach its destination, terminals, storage facilities and pipelines are needed. How quickly can these be built?

Thyssenkrupp's clean future begins in the mud. It is the end of December when the steel company has loaded onto the site of its Duisburg steelworks. And those with sturdy shoes have a clear advantage. Politicians, company representatives and journalists trudge through the churned-up earth to finally look together into a freshly dug trench. A dark pipe peeps out of the ground - that's all there is to see.

And yet a new era is to begin with this hole in the ground. So far, Europe's largest steelworks in Duisburg gobbles up five million tonnes of coal a year, enough to fill 83,000 train wagons. That is to change by 2045. The pipeline linking the plant to a long-distance network operated by the gas company Air Liquide is the first step: it is to supply the factory with the first quantities of hydrogen from 2024, followed by an even larger pipeline at the end of 2026. In Duisburg, Mona Neubaur, Minister of Economic Affairs of North Rhine-Westphalia, praises the success of the hydrogen economy.

"Hydrogen is the only element we can use to replace carbon in steel production," emphasises Bettina Hübschen, who is organising the conversion to the clean gas for the thyssenkrupp steelworks. A test plant is to start up in about two years, and the first of four blast furnaces in Duisburg is to be converted in four years. Final hydrogen requirement per year: 720,000 tonnes. It would take 3,800 wind turbines to produce this amount - as many as there are currently in the whole of North Rhine-Westphalia.

It was also because of figures like these that opinionated energy experts and politicians recently spoke of the "champagne of the energy transition", of rare hydrogen. But since Russia's attack on Ukraine, it is the price of natural gas that is reminiscent of champagne - burning liquefied natural gas (LNG) is now more expensive than hydrogen produced with green electricity in large parts of Europe, the energy market analysts at BloombergNEF reported in July. "The pressure to get significant quantities of hydrogen to Europe in this decade has increased significantly," says Jens Burchardt, a hydrogen expert at the Boston Consulting Group.

For the Duisburg plant, at least, the declarations of intent are already in place. BP, RWE and the Norwegian energy group Equinor have promised Thyssenkrupp hydrogen by pipeline. Shortly after the New Year, Vice-Chancellor Robert Habeck agreed with Norway's Prime Minister Jonas Gahr on imports of hydrogen, including a new pipeline through the North Sea. In two years' time, E.On and Uniper again want to import ammonia by ship from Canada, in which the hydrogen is chemically bound and thus easier to transport. "From 2025 onwards, considerable volumes of hydrogen will come to Europe," expects Jorgo Chatzimarkakis, head of Hydrogen Europe, the association representing the interests of the European hydrogen industry.

But is Germany prepared? Hardly at present. No other hydrogen pipelines are being built as quickly as those of the influential Thyssenkrupp group. He wants to switch to hydrogen, complains a medium-sized steel entrepreneur from South Westphalia. Only when It remains to be seen whether his plant will be connected to a pipeline. In the Ruhr region, in central Germany and near Brunsbüttel alone, a few hydrogen pipelines now connect chemical plants; they are 420 kilometres long in total. If the distribution networks in the cities are included, the German natural gas network extends over more than 600,000 kilometres. To supply the steelworks in Duisburg with imported hydrogen, for example, new terminals are needed on the coasts. Admittedly, a dozen such plants are planned from Wilhelmshaven to Lubmin, and others exist in the Netherlands and Belgium. But most of them are not initially intended for hydrogen, but for LNG. The draft of the new hydrogen strategy, which the Federal Ministry of Economics is expected to present shortly, now takes up the problem: It states that the rapid development of a terminal, grid and storage infrastructure for hydrogen is indispensable. A new company should build and operate the hydrogen network, with state participation. Plans that immediately drew criticism: private-sector players are much more efficient at rapidly transforming today's natural gas network into a hydrogen network, emphasises Timm Kehler, chairman of the industry association Zukunft Gas.

Killinger wants to avoid this - and plans his terminal as a "modular system for the energy transition", as he calls it. He expects the first ammonia deliveries to Stade in five years. At that point, smaller, specially built tanks could be used to store the chemical. If demand increases, one of the two large LNG tanks could be converted. According to Killinger, pumps, compressors and seals would have to be replaced - "parts that have to be replaced regularly anyway". The company would deliver the ammonia by ship or train wagon to chemical companies that need it as a raw material for the production of fertiliser, for example. Or it could be split in Stade to produce hydrogen. But the plants for this, so-called crackers, have never been built on the necessary scale. On top of that, the conversion process consumes a lot of energy. It is therefore impossible to predict exactly how expensive the hydrogen imported in this way will be. Nevertheless, the quantities needed by the huge steelworks in in Duisburg could be supplied by a plant like the one in Stade.

For this, however, the hydrogen would have to be transported from the coast to the Ruhr region - and reliably around the clock. In Etzel, a town with 800 inhabitants in East Frisia, 100 kilometres west of Stade, a team led by engineer Carsten Reekers is working to make this possible soon. There, on the grounds of the Storag Etzel company, cows graze, lapwings breed in the meadows, migrating geese rest in the marshland. A network of pipes, valves and pressure gauges tells of what is hidden deep underground: one of Germany's largest underground storage facilities for gas and crude oil. Starting at a depth of 800 metres, 75 caverns have been flushed into a salt dome here since the 1970s. Each cavern is 600 metres deep and would fit the Cologne Cathedral four high. The gas that is stored here will keep power stations and heating systems running this winter. 

Reekers, head of cavern operations, continues to plan ahead. At the end of the year, his team filled a half-finished cavern with a small amount of hydrogen. A first test to see if the underground storage facility will keep tight even with the volatile gas, which is 14 times lighter than oxygen. "Everything went like a picture book," enthuses Reekers.

As with natural gas, researchers expect demand for hydrogen to fluctuate over the year and possible supply gaps. The Federal Ministry of Economics and Technology therefore expects storage facilities with a capacity of up to 73 terawatt hours to be needed by 2050. Reekers plans to prepare the first two caverns in Etzel for this use in the course of the year. The pipe connection that leads about 1000 metres down into the cavern usually has to be replaced, he says. Just like the seal at the lower end of the pipe, called a packer.

Where the pipeline comes to light, a four-metre-high steel seal closes it off, weighing ten tonnes, which has to withstand 100 times the pressure of a car tyre over many years. This, too, has to be rebuilt and replaced for hydrogen operation. Just like many compressors, measuring instruments and seals. And because the salt caverns are polluted with residual natural gas and oil, filter systems will be needed in the future. Filter systems will be needed to clean the hydrogen after it is extracted from the storage facility.

In 2026, Reekers wants to be ready in case requests for hydrogen storage facilities arrive. So far, the green gas is still a rarity: for the test of the first two caverns, Storag Etzel is having it delivered by lorry - 150 loads from Innsbruck in Tyrol. It would be much more obvious to pump the gas through the existing natural gas pipelines across the country. And that, too, is now being tested. Between Bad Bentheim in Lower Saxony and Legden in North Rhine-Westphalia, for example, reconstruction work will begin this year. Here a section of pipeline is no longer needed for natural gas because production in the Netherlands has been throttled. It is part of GetH2, a pilot project of various energy suppliers and industrial companies. It is intended to create a hydrogen network that will connect important industrial centres by 2030 - a hydrogen production facility in Lingen in the Emsland region, for example, and the Evonik chemical park in Marl.

"We want to have the first Germany-wide hydrogen network ready by 2027".

FRANK HEUNEMANN, Managing Director of Nowega

After a series of studies and tests, the operators are certain: existing steel pipes in the gas network can in principle also be used for hydrogen. "It is true that the tiny individual hydrogen atoms that occur in rare cases can penetrate micro-cracks in the material more easily," says Frank Heunemann, managing director at gas network operator Nowega. Over decades, this could affect the pipeline walls. But the damaged areas can be easily localised: With the help of robots, so-called pigs, the operators regularly check the condition of the pipelines. Only where the walls have become too damaged for hydrogen operation does a section of pipeline have to be replaced.

In any case, valves have to be replaced that can be used to shut off natural gas pipelines every five to ten kilometres - for maintenance purposes, for example. As a rule, their sealing materials are not suitable for permanent contact with hydrogen. "The intervention is manageable," says Heunemann. When the hydrogen network expands towards the end of the decade, the first compressor stations will also have to be converted. The plants increase the pressure in the pipeline with rotating blades, similar to an aircraft turbine, so that the gas flows in front. "Hydrogen has a lower density than natural gas," says Heunemann, "so the compressors have to turn at a higher speed." To withstand the heavier load, blades made of new materials are needed.

The first parts of the GetH2 network are to be converted to hydrogen in 2024. The timetable depends on events that Heunemann and his comrades-in-arms can hardly influence: the promise of subsidies from the EU, breeding times of sand lizards that live on sections of the route, tight maintenance cycles of refineries where the pipelines can be connected. At Thyssenkrupp's Duisburg steelworks, they have therefore taken precautions: when the first converted blast furnace goes into operation in 2026, it will first run on a mix of hydrogen and natural gas - until enough green gas is available.

"Zukunft sucht Leerrohr", WiWo Print vom 13.01.2023. Autor: Andreas Menn