The company is currently represented in projects across all links of the value chain – from extraction to distribution to use – in order to better understand future customer needs and the associated potential for specialty chemicals. “Those who want to see the energy transition can’t avoid coupling sectors by means of hydrogen,” says Oliver Busch, the Head of Sustainable Businesses at Creavis, Evonik’s strategic innovation unit, which is working to develop new and sustainable business areas. “And if we do things right, the transition won’t pass us by either.” Together with Axel Kobus, the Head of Evonik’s Process Technology and Engineering Business Line, Busch wants to promote the hydrogen agenda. “As an industrial group, we have an especially large number of contact points,” says Kobus. For example, Evonik produces hydrogen for numerous users and operates hydrogen pipelines that supply a variety of industrial companies. The Group also supplies innovative process technologies and products that could close gaps in the hydrogen economy. Kobus and Busch agree that “in this area we can provide substantial added value as a supplier of solutions.”

At the Marl Chemical Park, it’s especially clear to see how multifaceted the uses of hydrogen already are today. “In this industrial park, which is home to almost 20 companies, hydrogen is used in nearly every laboratory and every plant—not always in large amounts, but almost always for crucial processes,” says Swen Fritsch, the manager in charge of hydrogen operations at this location. The location’s steam reformer delivers several tens of thousands of cubic meters of pure hydrogen per hour. Most of this production volume is used to cover the site’s own needs; the rest is drawn off directly by industrial gas suppliers from the region at their own filling stations. Marl has the biggest hydrogen filling station in Europe.

Steam reformers like the one in Marl cover more than 95 percent of the worldwide demand for hydrogen. They use heat, pressure, and catalysts to produce hydrogen from fossil sources such as natural gas. This process generates about ten tons of carbon dioxide (CO₂) per ton of hydrogen. According to the International Energy Agency (IEA), in recent years hydrogen production has generated about 830 million tons of CO₂ emissions worldwide per year. That’s more than the emissions of the UK, France, and the Czech Republic taken together. This is not a good balance sheet for hydrogen, the beacon of hope for advocates of an energy transition.

However, a different approach would also be possible. Hydrogen can be produced directly from water by means of electrolysis. The principle is simple and well known: A voltage applied between two electrodes splits water into its chemical components, oxygen and hydrogen. In a fuel cell, this process is reversed: Hydrogen and oxygen from the air react without combustion to form water. The reaction generates an electric current and some waste heat. Within this cycle, hydrogen is the storage medium for electrical energy. This potentially climate-neutral cycle, which is expected to spur the energy transition, is now attracting large amounts of attention and ­capital.

The magic words here are “sector coupling” and “power-to-X.” In other words, the aim is to store “green” energy, make it transportable, and use it in a variety of applications. Hydrogen makes this possible. It can be produced directly at the sites where renewable energy is inexpensive to produce. It’s easy to store it and transport it to distant consumers via pipelines. And depending on the user’s needs, it can be burned, used as a material or reconverted into electric current.

Hydrogen has a wide variety of possible applications. For example, cars powered by fuel cells can already drive further on one tank filling than most battery-powered cars and—unlike plug-in vehicles—they can be completely refueled in a few minutes. However, they have not been commercially successful so far. At last count, only 6,558 hydrogen-powered cars were on the road in the USA; in Germany, there were fewer than 400. There still is no network of filling stations, and the technology is still too expensive and too bulky for the mass market. State-of-the-art materials could help to change this situation. For example, thanks to specialized crosslinkers from Evonik, fiber-reinforced plastics can be used to make safe hydrogen storage tanks for vehicles and filling stations that are significantly lighter and cheaper than the gas containers available today.

This technology could become established for commercial vehicles sooner than for cars. Regular-service buses, for example, always use the same filling station, weigh about 20 tons with a full load of passengers, and have a purchase price of more than €200,000. So the present-day disadvantages of fuel cells play a lesser role. The situation of trains is similar: According to a study conducted by the German Aerospace Center, hydrogen-powered trains are the best option for replacing diesel-powered locomotives, especially on long branch lines without overhead wires. Germany’s first hydrogen-powered train is already making regular runs in the region around Cuxhaven. Shipyards are also trying out this technology. Norway aims to convert its many ferryboats to fuel-cell operation. And even the aviation industry hopes that hydrogen will one day be driving normal turbines by means of fuel cells or after being processed to form methanol and then kerosene.

Meanwhile, large fuel cells for reconversion are currently attracting interest as buffers for the power grid, and several producers of heating systems are offering small devices that supply households with both electricity and heat.

But the greatest hunger for hydrogen can be found in industrial companies—especially among steel producers. According to its sector association, Germany’s steel industry could be operating completely CO₂-neutrally by 2050. What’s more, it probably needs to do so if it doesn’t want increasing penalties for CO₂ emissions to force it off the global market altogether. Thyssenkrupp plans to use hydrogen to reduce the emissions from its blast furnaces and make the remaining waste gases usable for chemical products. ­Carbon2Chem, a development project in which Evonik is participating, is searching for ways to manufacture chemical precursor products from burned carbon. For the long term, however, almost all steel producers are focusing on the direct reduction process, which thanks to hydrogen operates completely without carbon and coke.

This technological transition will cost Thyssenkrupp about €10 billion in the coming decades, according to the experts at the group’s headquarters in Duisburg. And the volumes of hydrogen that will be needed for this transition are gigantic. “Around 2050, we will need about eight billion cubic meters of hydrogen per year,” says Jens Reichel, who heads the Sustainable Production unit at Thyssenkrupp. According to Reichel, in order to produce this volume of hydrogen via electrolysis, 40 tera­watt­hours of energy are needed. That’s the approximate output of eight of the biggest Irsching 5 natural-gas power plants or about 3,800 offshore wind turbines in the three-megawatt class.

This has been a tremendous spur for the developers of efficient electrolytic processes. The oldest, and so far the most frequently used, technology for hydrogen production by means of electricity is alkaline electrolysis. A newer technology called Proton Exchange Membrane (PEM) electrolysis has been gaining ground for about two decades. Other processes, such as solid oxide electrolysis, promise to be even more efficient but are still objects of research. Evonik too is working on key materials for new processes (read more here).

According to the IEA, currently less than 0.1 percent of the hydrogen produced around the world comes from electrolysis. The expansion of these capacities has begun. Since 2000, the IEA’s database has registered more than 300 hydrogen projects that are either under construction or in the planning stage. Most of them are in Germany. Recently, however, new electrolysis facilities have on average had a capacity of just one megawatt. In the town of Wesseling near Cologne, Shell is building the world’s biggest electrolysis facility, which will have a capacity of ten megawatts. The IEA estimates that the next generation of such facilities will deliver 100 megawatts or more. However, ten of these facilities would be needed in order to supply a single steel mill with hydrogen. A number of experts are therefore skeptical as to whether Germany can cover its predicted hydrogen requirements soon enough by means of electrolysis.

Added to these technical hurdles are economic ones: “Green” hydrogen is currently about three times as expensive in central Europe as “gray” hydrogen derived from natural gas. Because modern steam reformers like the one in Marl supply hydrogen efficiently and reliably, and because hydrogen is essential to the creation of the network, many experts in the sector believe that these steam reformers will have to play a crucial role in the medium term. The carbon dioxide generated in the process could be captured and stored. Hydrogen produced in this way is referred to as “blue” hydrogen. On a large industrial scale, this storage might take place in the underground reservoirs that remain after the extraction of natural gas. However, such caverns exist in only a few regions, and the technology itself is controversial (read more here).

Another possibility is to capture and process the CO₂ that is emitted. For example, instead of hydrogen and carbon dioxide the steam reformer in Marl could also produce synthesis gas, which is a mixture of hydrogen and carbon monoxide—a common precursor product for the chemical industry. Evonik itself is working on a whole series of research projects that aim to use industrial waste gases to produce valuable intermediate and special products for the chemical industry in small modular plants. For example, Evonik is cooperating with the power plant operator STEAG and the University of ­Duisburg-Essen on the Vulcanus project, which is developing a new process chain that uses carbon dioxide and methane to produce higher alcohols for the production of high performance polymers.

In the future, industrialized countries may also be able to import more and cheaper hydrogen from renewable sources, for example from North Africa. The Desertec project was launched there more than a decade ago. The original aim was to transport solar and wind energy from the Sahara via direct-current lines through the Mediterranean to Europe. This aim was not achieved. The new hope is that the energy from the Sahara, in the form of green hydrogen, could be delivered to consumers by ship or by pipeline.

On principle, it’s easy to transport hydrogen, but not every means of transportation is efficient. Because of the extremely low density of this gas, even 40-ton trucks with their impressive white high-pressure tanks can carry only about 300 kilograms of hydrogen. That’s only a little more than the permissible load of a smart. Even the largest available tank trucks can transport a maximum of 1.1 tons of hydrogen at a pressure of 500 bar.

The low density of hydrogen also creates problems related to storage. In chemical parks such as the one in Marl you can find lots of gasometers and big pressurized containers full of oxygen, nitrogen, methane or ethylene, but you would look in vain for big tanks of hydrogen. Hydrogen can be compressed into cost-effective tank volumes only under tremendous pressure. It’s true that hydrogen can be stored in the underground cavities that are left behind after the extraction of salt or natural gas. However, just like natural CO₂ storage facilities, they can be found in only a few regions. Hydrogen can be stored in a liquid, and thus especially compact, form only at a temperature of -253°C. That requires a great deal of cooling energy and elaborate insulation.

“The only really efficient way to distribute hydrogen is via pipeline,” says Thomas Basten, who heads Evonik’s logistics business involving pipelines for all kinds of industrial gases and liquids. The Group operates more than 2,000 kilometers of pipelines all over Germany, three quarters of them under contract for other companies. In this function, Evonik is a participant of an initiative called GET H2, which is planning a public hydrogen network for Germany. The plans call for the network’s “core” to initially be a 100-megawatt electrolysis facility that is being planned by the RWE power company in the town of Lingen—that’s why the project is called Nukleus. Here in the Emsland region, not far from numerous wind farms in the countryside and in the North Sea, plans call for generating hydrogen by means of wind power.

RWE aims to transport this wind energy in the form of green hydrogen to industrial consumers by means of pipelines. One of these consumers is the BP oil refinery on the site; others are located in the Marl Chemical Park in North Rhine-Westphalia. A 130-kilometer-long steel pipeline could easily deliver up to 100,000 cubic meters of hydrogen per hour and help to supply consumers in the region. Best of all, a connection of this kind already exists, and it’s partly operated by Evonik. These are pipelines that in some cases have become available because the Netherlands has discontinued its natural-gas business; these pipelines can be converted for carrying hydrogen.

“The pipeline business is not for poor people,” says Basten. Laying pipelines has always been an expensive enterprise. In particular, fulfilling the bureaucratic requirements consumes a great deal of resources. That makes the use of existing pipelines an attractive option. Germany currently has approximately 50,000 kilometers of high-pressure pipelines for natural gas. If green electricity in the form of hydrogen is flowing through parts of this infrastructure, it might be unnecessary to build additional power lines.

At Evonik, this idea is being developed even further: Thanks to a Group-owned membrane technology, some parts of Germany’s many-branched natural-gas distribution network, which is 500,000 kilometers long, could be repurposed. Commercially available natural gas already contains a low percentage of hydrogen today. However, more hydrogen could also flow through these pipelines in piggyback fashion without any problems. At various points in the network, Sepuran^® membranes from ­Evonik could be used to divert hydrogen for supplying filling stations or other consumers, for example.

In order to finally make the vision of a hydrogen economy a reality after 150 years, many factors have to come together: The network, the supply system, the demand, and the technology—all of these factors must develop in parallel while the price of green hydrogen decreases. This is where national governments must step in. “Everyone’s waiting to see the German government’s national hydrogen strategy,” says Basten. “It would have to exempt hydrogen electrolysis facilities from the EEG-surcharge, change the energy industry law to permit the transportation of hydrogen in public networks, and create incentives for consumers to use green hydrogen.” It’s important to coordinate national planning and international partnerships. Evonik too wants to combine its numerous activities related to hydrogen within a comprehensive strategy. The Group’s experts are feeling the growing pressure of the market. “Our customers want concrete answers regarding the CO₂ backpack that our products are dragging around with them,” says Axel Kobus, the process technology engineer who is responsible for Life Cycle Management, among other things.

That’s why the Group’s hydrogen peroxide department in particular is considering when and how it can procure green hydrogen at market-appropriate prices—and how it can capture and process its own steam reformers’ carbon dioxide emissions until then.

Unlike the steel industry and the energy business, the chemical industry is not aiming to exclude carbon from these processes. Carbon is a basic component of chemical products, and for that reason alone it’s much too valuable to be burned and blown into the sky, says the Creavis manager Oliver Busch. “The ideal we are working on in the chemical industry is closed material cycles. Hydrogen offers us the unique opportunity to close material and energy cycles simultaneously.” Now it’s only a matter of putting together all the pieces of the puzzle.

If hydrogen is produced via electrolysis using renewable energy, no CO₂ is generated.

About ten tons of carbon dioxide are generated for each ton of hydrogen produced in steam reformers using fossil energy carriers such as natural gas.

The carbon dioxide from steam reformers can be captured and compressed in underground cavities, usually former storage facilities for natural gas. This process is controversial.

In methane pyrolysis, biogas or natural gas is cracked in a reactor with liquid metal. This generates only hydrogen and solid carbon, which can be stored or used. This method is the object of research.