The storage named H2compact 6000 holds 6,000 litres. It was tested by the testing institute LRQA Germany according to the Pressure Equipment Directive 2014/68/EU and is expected to receive its CE certificate soon, according to Ambartec. Series production is to be implemented by the partner Purem in Wilsdruff, Saxony. "Next year, our customers can receive the first containers, after which we plan to ramp up production to several hundred containers," says Ambartec CEO Matthias Rudloff.
To prepare for series production of the pressure vessels, the development of a modular production concept is first on the agenda. Purem's origins lie in exhaust and acoustic technology. The company brings expertise in industrialisation and steel processing, enabling it to convert the prototype design into scalable production, according to Ambartec. Qualifications for the production employees are still on the agenda for the special requirements of the hydrogen tanks.
Strategic Collaboration with Purem by Eberspächer
Purem by Eberspächer has been involved in the design and development of the containers at Ambartec since the beginning of the cooperation in January 2025. Conversely, Purem connects Ambartec with strategic partners, such as from the steel industry or the hydrogen economy. The contacts concern "both the storage and transport of hydrogen as well as our offer to supply companies with silver hydrogen," says Ambartec's technical director Uwe Pahl. This is how Ambartec refers to the hydrogen that actually occurs as exhaust gas but can be captured and utilised with the company's storage technology. The colour designation derives from the fact that the nuggets become silvery metallic iron when loaded.
Storage as Iron Nugget
The Ambartec storage units are not strictly speaking hydrogen storage, even though they are used as such. Nuggets of iron oxide react with hydrogen during loading to form metallic iron and water vapour. This reaction is also under discussion in the steel industry when it comes to extracting iron from iron oxide. The hydrogen thus leaves the storage with the steam. To extract hydrogen again from the Ambartec storage, the iron pellets are brought together with water vapour. The oxygen reacts again with the iron, releasing the hydrogen.
Ambartec speaks of an "excellent energy balance" that has been demonstrated in the multi-month test at the demonstration plant. If the water vapour generated during loading is used in a high-temperature electrolysis (SOEC), efficiencies of over 80 percent can be achieved. Another special feature is that the storage can be loaded not only with pure hydrogen but also with blast furnace gases or with synthesis gases from biogenic residues or sewage sludge.
Ambartec specifies the storage capacity of the H2compact 6000 Plus as 800 kg of hydrogen (one should actually say virtual hydrogen) or 26 megawatt-hours. The storage is installed in conventional 20-foot containers, making it easy to move and transport by truck, ship, train, or crane. This also facilitates approvals according to the Federal Immission Control Act (BImSchG) or the Major Accidents Ordinance.
