(Dresden) – The hydrogen filling station network is to be expanded in the next few years. This is of little use to small vehicles such as e-scooters and scooters: the pressure surge when refueling would be too great.
The Fraunhofer Institute for Manufacturing Technology and Applied Materials Research IFAM in Dresden has developed a solution for small vehicles and called it “Powerpaste”. The principle: Instead of driving to a gas station, the driver of a scooter, for example, simply changes a cartridge and also fills a water tank with tap water.
Power from the paste
A stamp presses the power paste out of the cartridge in a closed system. If water is added from the water tank, gaseous hydrogen is formed. According to the information, the amount is dynamically adjusted to the hydrogen requirements of a fuel cell, which then generates the electricity for the drive.
Only half of the hydrogen comes from the paste, the other half comes from the water. “With the power paste, hydrogen can be chemically stored at room temperature and ambient pressure and released again as needed,” says Marcus Vogt, scientist at Fraunhofer IFAM. This is not critical even if the scooter is left in the sun for hours in the summer: the power paste only decomposes above around 250 degrees Celsius.
The basis is magnesium
The starting material of the paste is powdered magnesium, one of the most common elements and a readily available raw material. At 350 degrees Celsius and five to six times atmospheric pressure, the material is synthesized with hydrogen to form magnesium hydride. There are also esters and metal salts.
The energy storage density is significantly higher than with a 700 bar pressure tank. “Compared to batteries, it even has ten times the energy storage density,” says Macus Vogt. A vehicle achieves a similar range with the power paste as with the same amount of gasoline. The paste also performs better when comparing the range with hydrogen compressed to 700 bar.
According to the researchers, the new material is also interesting for cars or range extenders - which increase the range of electric cars. Drones could stay in the air for several hours with the hydrogen paste, for example to check forests and power lines. The scientists also see possible uses in the leisure sector: When camping, the power paste could use fuel cells to supply electricity for coffee machines and toasters.
Simple infrastructure
Filling stations for high-pressure gaseous hydrogen currently cost around one million euros per pump. Powerpaste can also be used where there is no hydrogen pump. The paste is flowable and pumpable - it can therefore also be filled using comparatively inexpensive filling systems. According to IFAM, the investment costs are only a few tens of thousands of euros.
Pilot center planned for 2021
In order to test the theory in practice, Fraunhofer IFAM is currently building a production facility for the power paste at the Fraunhofer Project Center for Energy Storage and Systems ZESS. This is scheduled to go into operation at the end of 2021 and then produce up to four tons per year. IFAM does not provide any information about the costs.
Photo above
Powerpaste / © Fraunhofer IFAM
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Demonstration system of a power generator with inserted power paste cartridge and 100-watt PEM fuel cell / © Fraunhofer IFAM
