When it comes to the green future of technology, Athina Megari and Patrick Krieger are buzzing with vigour. The two are supporting projects in very different areas of TÜV NORD in which the focus is on the use of hydrogen. Athina Megari is a process engineer who is working in Hamburg in the ENCOS team on the implementation of hydrogen applications in existing industrial plants. Patrick Krieger, on the other hand, is responsible for the big picture at the ENERGY ENGINEERS in Gelsenkirchen. As project manager, the economist is overseeing some important hydrogen initiatives in North Rhine-Westphalia. Ms Megari and Mr Krieger are both convinced that hydrogen could pave the way to the energy transition and a future without harmful greenhouse gases.

Hydrogen is changing the entire industry

“The interest in hydrogen isn’t really new," says Patrick Krieger. “In the past, however, it was always about standalone solutions, such as alternatives to petrol in cars.” Today, the view is much more comprehensive. “Hydrogen offers opportunities for a sustainable overall concept that will change every aspect of industrial value creation.” This means that hydrogen technologies can be used not only to store energy generated from renewable sources, but also to develop completely new processes for industrial production processes – without harmful emissions of greenhouse gases. “The strength of hydrogen clearly lies in its energetic and material properties,” explains the project manager.

What makes hydrogen so special? “My professor at the University of Thessaloniki always used to say that hydrogen is very useful, but is unfortunately almost never found on its own,” says Athina Megari. “This is both a great challenge and a huge opportunity.” Since pure hydrogen is hardly ever present in nature, it must first be extracted from water and separated from oxygen by electrolysis – or from carbon atoms, for example, if it is obtained from natural gas or biomass using other processes. At the same time, however, the enormous readiness of hydrogen atoms to bond also offers great advantages: “If pure hydrogen bonds with carbon, it can be transported over long distances in gas form as methane or as liquid methanol. And it can serve as a basis for the production of synthetic fuels in refineries or as a raw material for industry,” says the process engineer.

The political goal, as is the case, for example, with the German government's National Hydrogen Strategy, is to make green hydrogen usable as quickly as possible. However, a great deal of spadework will have to be done first. For instance, neither the electrolysis capacity nor the amount of energy that can be produced from regenerative sources are sufficient to meet the enormous demand. In addition, huge investments will be needed for its material use, for example in the steel industry.

After all, the production of “green” steel would require the replacement of today’s blast furnaces with direct reduction plants. Nevertheless, both experts agree that there must be a complete switch to green hydrogen in the long term. “Until then, in a transitional period, we’ll have to make use of the entire hydrogen colour spectrum,” says Patrick Krieger. Athina Megari is also clear that “many small steps are necessary for the complete greening of industry”.

Carbon-neutral freight transport from the North Sea to the Alps

Patrick Krieger is the project manager of “RH2INE”, in which the state of North Rhine-Westphalia and the province of South Holland are involved. “The long-term vision is one of carbon-neutral freight transport by water, rail and road between the North Sea and the Alps,” he explains. First of all, inland shipping will need to be converted to hydrogen. As much of the existing infrastructure as possible will be used. This includes, for example, the Dutch pipeline network, which is now being readied to carry hydrogen after the cessation of natural gas production. In addition, new hydrogen sources are being developed: “Because companies in the chemical industry are also involved, we can also use secondary hydrogen from chlorine production,” he says. “The carbon produced by methane pyrolysis could be used in the tyre industry.” To this end, Patrick Krieger is coordinating all the important players: shipping companies, ports, railway companies, the logistics industry and local industrial companies.

A particular challenge arises in respect of refuelling ships with hydrogen. “Conventional plants aren’t suitable because hydrogen, as a gas, has completely different requirements than heavy fuel oil,” explains the project manager. “We’re therefore developing a system with interchangeable containers that are filled with hydrogen on land and only need to be swapped once they’re on board a ship.” A major problem, however, is not only the implementation of new technologies, but also the gaps in the legal framework: “We expect the use of fuel cells on ships on the Rhine powered by hydrogen not to be fully regulated until 2025.”

Does decarbonisation by hydrogen imply that there is going to be a split between “old” and “new” industries? No, this isn’t a revolution, but a normal process, says Athina Megari: “From coal to oil via natural gas, hydrogen is another step towards decarbonisation." What matters now is to translate the theory into practical and economical technical solutions as quickly as possible.

Experts on the transition

Before the industrial sector can finally switch over to using hydrogen, many tech­nical conditions still need to be put in place. However, it is already possible to reduce harmful greenhouse gas emissions today. DMT expert Michael Bohn has developed a process in the steel industry for this purpose.

Although the production of “green” steel with hydrogen will be possible in the long term, this will require enormous investments over the coming decades. The conventional blast furnaces would have to be completely replaced by new direct reduction systems. “We still need coke in today’s blast furnaces because the carbon has to combine with the steel in production,” explains engineer Michael Bohn. He worked in a steel mill for many years and is therefore familiar with the high demands placed on steel production.

Michael Bohn and his team have already managed to significantly reduce CO₂ emissions from steel production and make production more efficient using a fine gas purification process. They use the gas which is in any case generated in the production of coke – a mixture with a low calorific value which contains such substances as ammonia, tar and sulphur. After scrubbing, the coking plant gas has a hydrogen content of about 80 percent. “We then have a quality equivalent to that of natural gas,” says Mr Bohn. “The gas is then used directly on site to reduce the amount of coke in the blast furnace thanks to its much higher energy density.”

Moreover, turbines or small power plants can be operated on the factory premises or in the vicinity. Mr Bohn sees this as an important bridging technology: “Conventional blast furnaces can already be converted, espe­cially where natural gas is very expensive.” Another advantage is that the waste can be recycled. “The sulphur produced by scrubbing coking plant gas can be sold on the world market as a raw material for industrial production, which further reduces the need to break down elementary sulphur.”