Porträt
Der Physiker und Idealist
Am Helmholtz-Zentrum Hereon entwickelt Martin Dornheim effiziente Wasserstoffspeicher auf der Basis von Metallhydriden (Bild: Hereon/Rolf Otzipka).
Martin Dornheim arbeitet an Tanks, in denen sich jede Menge Wasserstoff effizient speichern lässt. Damit will er den Weg ebnen, um Autos mit Brennstoffzellen flächendeckend auf die Straße zu bringen – und die Welt ein klein wenig besser machen.
Sometimes Martin Dornheim needs the sound of the treetops. He then leaves his office at the Helmholtz-Zentrum Hereon during his lunch break. He is drawn to the forest surrounding the large science campus in Geesthacht to exercise and reflect. This hour in nature also rekindles an old passion of the physicist: As a young student, he wanted to become a forester - and today, several decades later, Martin Dornheim realizes that now, with his hydrogen research, he is actually pursuing the same goal he would have been concerned with as a forester: protecting nature and making the world a little better.
Efficient hydrogen storage of the future
However, there is one route that Dornheim takes more often on the research center campus than into the forest: It leads into the laboratories and the impressive factory hall that was built here a few years ago for his team's research. There are so-called high-energy mills - the largest of them look like steel drums, in which steel balls are set in motion by vibration, rotation or an agitator arm, some of which are the size of golf balls and others measure only a few millimeters. When they collide with force, they pulverize the ground material. "We use them to produce a fine powder that absorbs the hydrogen like a sponge," Martin Dornheim explains. The fine powder is metal hydrides - metals that easily form a bond with hydrogen. The Geesthacht scientists' research is based on these materials: they are developing the most efficient hydrogen storage systems possible based on metal hydrides. "There are many pores and channels between the powder particles," says Dornheim. "Through them, the hydrogen can spread quickly and is chemically bound in the metal." In this way, it can be stored and released from the chemical bond again and again as needed.
Martin Dornheim heads the Materials Design Department at the Helmholtz-Zentrum Hereon (Image: Hereon/Rolf Otzipka).
When Martin Dornheim talks about this, you can see his enthusiasm for the subject - even when he talks about the sticking points of storage technology. Among other things, they lie in the necessary heat supply. "When I started working on this topic in Geesthacht almost 20 years ago, magnesium was the focus of research," he recalls - the metal stores a particularly large amount of hydrogen, but at a very high reaction temperature. This means that when the stored hydrogen is retrieved, the material has to be heated to a high temperature to do so - and that is a major obstacle for many applications. "Since then, we have been concentrating on the search for metal hydrides that achieve a similarly high storage capacity but have a much lower heat requirement," explains Martin Dornheim, who only last year received the prestigious "Science of Hydrogen & Energy Award" for his research work in Japan.
Hydrogen as a beacon of hope for the energy transition
Since 2005, he has been an expert in the International Energy Agency's Hydrogen Technology Collaboration Program and regularly discusses and consults with international partners on possible new paths and advances in hydrogen storage. He is also co-responsible for creating and developing the European Hydrogen Roadmap. He regularly explains what he is working on, even in front of television cameras, because hydrogen is increasingly attracting public attention as a beacon of hope for the energy transition. Just recently, Martin Dornheim and his colleagues were featured on an evening television program: There, Dornheim sat at the wheel of a hydrogen-powered off-road vehicle and roared along the roads around Geesthacht - "this is a small-series vehicle that we use here as a company car," he explains. The car is equipped with a hydrogen tank ex works, and Dornheim uses it primarily to explain his own technology: While previous vehicles like the Hereon service car still have a large pressurized tank on board, in which hydrogen is stored at 700 bar - 700 times atmospheric pressure - metal hydrides allow a different approach to be taken. Researchers are working on tanks in which finely ground metal hydride particles store the hydrogen - entirely without such high pressures and thus much more safely.
"I am convinced that hydrogen technology will prevail in many areas."
"I became interested in the natural sciences at an early age. While others read novels or were on the soccer field, I preferred non-fiction books. From the moment the content of school physics also slowly became more complicated and thus more interesting for me, physics became one of my favorite subjects, along with Latin and mathematics," Martin Dornheim recalls of his school days. That's why he then decided to study physics - and specialized in solid-state physics at an early stage. "It was clear to me that there were many points of contact for application," he says in retrospect; for precisely the kind of research he is now conducting. And this is where he comes full circle to his early career aspiration of becoming a forester: "Back in the 1980s, forest dieback was a big topic that really moved me as a student," he says. As a forester, he could only have contributed to improving the situation to a very limited extent; but this is exactly what still drives him today as a scientist: to contribute to a more environmentally friendly life.
"I am convinced that hydrogen technology will become established in many areas and can thus significantly reduce or even replace the use of fossil fuels. Fuel cell vehicles will also become established," he says, and immediately makes a prediction: "In 2050, cars with fuel cells and battery electric vehicles will both have large shares of the market. The advantages of fuel cell vehicles over pure battery electric vehicles are their greater range and faster refueling time." The temporal decoupling of wind and solar energy production and the use of this energy for refueling or charging is also a major advantage over the battery, he says.
He himself still drives privately with conventional technology, as there is not yet a hydrogen filling station in his district: He lives in the Lüneburg area with his wife and five children - and is increasingly annoyed by the daily commute to Geesthacht in Schleswig-Holstein.
At least he can make good use of the time and repeat vocabulary: Martin Dornheim is currently learning Hebrew. As a practicing Christian, he is an avid Bible reader and wants to get closer to the original text. "But it's depressing how slowly I'm progressing with language learning," he then complains. The fact that he keeps at it despite this probably has to do with his scientific experience: patience and staying power lead to success in the end - after all, he has already experienced this many times in his research.
Readers comments