Metal hydride storage is suitable as a hydrogen storage for ships, cars and airplanes. Until now, however, production has been expensive and harmful to the environment. A new recycling process solves this problem.

Geesthacht (Germany). In industry and research, hydrogen is considered one of the most promising energy carriers of the future. An example of this is the Airbus group, which intends to bring climate-neutral hydrogen-powered aircraft onto the market by 2035. So far, however, the storage of the very volatile hydrogen has been problematic and usually takes place under high pressure or at very low temperatures.

Alternatively, gaseous hydrogen can also be stored in metal hydride storage. These are certain metal compounds that can absorb hydrogen at moderate temperatures and low pressures. The functional principle of the metal hydrides can be compared to a sponge that can quickly absorb water and release it again. So far, however, the production of metal hydride storage has been expensive and harmful to the climate.

Metal hydride storage made from recycled industrial waste

Scientists at the Institute for Hydrogen Technology – Helmholtz Center Hereon have now discovered that hydrogen can also be stored in a more climate-friendly way. According to their publications in Journal of Magnesium and Alloys and in the trade magazine Green Chemistry the researchers succeeded in producing metal hydrides from recycled industrial waste. The previously used high-purity metals, the mining of which is cost-intensive and pollutes the environment, are therefore no longer necessary for the production of metal hydride storage tanks.

“Using circular economy approaches to produce hydrogen storage materials allows us to address the energy challenges of our time in a more sustainable way,” explains Claudio Pistidda.

Million tons of suitable industrial waste

According to the researchers, each produces several million tons of industrial waste that can be further processed into metal hydrides using their process. The innovative recycling process even makes it possible to use materials that previously could not be recycled. Accordingly, there were enough starting materials to be able to produce the environmentally and climate-friendly metal hydride storage tanks on an industrial scale.

Journal of Magnesium and Alloys, doi: 10.1016/j.jma.2021.12.005

Green Chemistry, doi: 10.1039/D2GC01983C