Patent of the month January
Carbon fibre high pressure vessels for gaseous hydrogen storage
The climate crisis will remain a challenge in the New Year. The shift of individual transport to CO2-neutral engines is of great importance for the success of the energy transition. Besides battery-powered vehicles, hydrogen-oxygen fuel cell technology is considered a solution approach for e-mobility. NPROXX Jülich GmbH took an important step in this direction with the development of high-pressure carbon fibre storage systems for gaseous hydrogen storage. On 10th of November 2020, the company was awarded with the AC² Innovation Prize of the Aachen region for this project.
The promising innovation was filed for patent in Germany in 2018 as DE102018110049A1 with the title: 'Process for manufacturing a fibre-reinforced pressure vessel with pole cap reinforcement'. Thus, it is our Patent of the Month for January.
For storing gaseous hydrogen in fuel cell vehicles, high-pressure tanks made of carbon fibre reinforced plastics (CFRP) have proven themselves. The lightweight tanks consist of a cylindrical centre section closed on both sides by curved poles. The advanced CFRP materials are characterised by excellent mechanical strength and stability.
Disadvantage: The fibre-reinforced products are far more expensive to manufacture than comparable metal devices! The cause of this is the method of pole cap reinforcement. To guarantee the deposition of the fibres on the pole caps, the cylinders have to be wrapped with additional fibre layers. This results in high material costs in the production of CFRP pressure vessels.
There are alternative solutions for reinforcing the pole cap area, e.g. by using pre-impregnated fibre tapes (prepregs), or by additional holding structures on which the fibres to be wound up find support. However, these process steps are associated with additional handling as well as higher production times and costs.
This is precisely where the work of the NPROXX GmbH comes in. The Jülich-based company has developed an innovative technology that clearly stands out from conventional products thanks to material savings, weight reduction and manufacturing technology. The novel process eliminates costly upstream process steps and reduces the manufacturing expense of the pressure vessels. Hence, the products represent a milestone as a tank and transport solution for the gaseous storage of hydrogen.
Now, how does it work? The innovation of pole cap reinforcement includes a separate retaining device with several protruding retaining elements. This allows the carbon fibres to be deposited and fastened in the pole cap area and then turned in the end section of the pressure vessel cylinder. The reinforcement is fixed to the tail of the pressure vessel cylinder by a circumferential winding, so that the fibres can be cut between this circumferential winding and the holding device. Afterwards, the retainer is removed and can be used for further reinforcement.
Overall, the optimised storage containers represent an ideal solution in the field of vehicles and transport for the mobility of the future. NPROXX considers itself part of the innovative technology region of Aachen and is currently working on expanding the production capacities.
The Patent & Standards Centre would like to wish you a happy and innovative new year!
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