A global pull towards Net-Zero emissions demands the shift towards clean energy technologies in all industrial sectors. Hydrogen as a clean burning fuel is essential in the global journey towards a Net-Zero future. Due to its low density, and therefore, low energy density per­-unit­-volume, hydrogen is compressed to very high-­pressure levels (up to 700bar), to facilitate a space-­efficient combustible energy. With the shift to a Net­-Zero transportation sector, the cost and performance requirements of the automotive and aerospace sectors are placing new and stringent specifications on the next generation of hydrogen-­pressure-­vessels (HPVs). The stringent space and weight constraints imply the need for high-performance compact and light HPVs, and simultaneously, the high-­volume production rates require low-­cost and low­-variability designs.

The use of composites has long been seen as an enabler to deliver lightweight solutions with ultimate structural performance. Current state-­of­-the-­art in HPV manufacture is to use a cylindrical metallic liner with domed end-caps that is overwrapped by carbon­-fibre filament (filament­-winding). As shapes and load-­paths of HPVs are very complex, placement of fibres with current techniques is far from optimal often leading to severe process-induced defects and significant material build-­up over the domes adding superfluous and sacrificial mass to the HPV. Hence, current state-­of-­the-­art filament-­wound HPVs are at a processing im­passe and cannot lead to the optimised solutions required to facilitate a step­-change in HPV design.

Such a step-change is only possible through iCOMAT's (Bristol University spin-out) Rapid-Tow-Shearing (RTS) process, the world's first automated tape-laying technology that can fibre-steer without defects drastically expanding the design space of composite components. To date, iCOMAT is the first/only UK automated composites-manufacturing machine supplier. RTS is currently used for 2.5D structures; 2D-preforms that are then formed into complex shapes. The aim here is to further develop RTS to enable direct 3D-­deposition for the manufacture of high-tech HPVs. The PYDRO project will begin in September 2022 and runs for 12 months, by which point a prototype industrial grade 3D-RTS head will be produced and a demonstrator HPV used in automotive applications will be manufactured.

Overall, PYDRO will demonstrate that high-­quality HPVs can be manufactured using RTS. By placing the fibres in the optimum orientation PYDRO is expected to deliver the new state-­of-­the-­art in HPVs in terms of structural performance.