Hydrogen is increasingly viewed as a key vector of the energy transition, with over one thousand projects announced worldwide for the development of hydrogen technologies, as part of the goal of attaining carbon neutrality by 2050.

In order to be part of this energy transition, Amorim Cork Composites has invested in various innovation and development projects to extend its Amorim Tech Seal portfolio - a range of cork composite materials for sealing – using materials that meet the demanding requirements of this new energy source.

Hydrogen is a fuel that behaves differently from natural gas, and therefore requires adaptation and development of specific infrastructures, devices and safety standards. Its dispersion behaviour differs from other gases, due to the small size of hydrogen atoms, and this increases the challenges for developing effective sealing joints for this gas.

To guarantee impermeability to hydrogen, Amorim Cork Composites has tested two cork-based materials: cork&EPDM and cork&NBR. The test was conducted in accordance with European standard EN 13555, a recognised methodology for assessing the stress and impermeability of sealing joints under pressure conditions. However, deviating from the standard practice, hydrogen (H2) was used as the test gas instead of helium.

The sealing joints were prepared with DN40/PN40 dimensions, with an outer diameter of 92 mm, an inner diameter of 49 mm and thickness of 3 mm. A servo-hydraulic press (TEMESfl.ai1) was used to apply and measure the stress, with loading and unloading cycles to assess the leakage rates. Hydrogen was maintained at 10 bar and leakage rates were measured at different stress levels: from 2 MPa to 20 MPa for cork&EPDM and from 4 MPa to 40 MPa for cork&NBR.

The tests revealed that both the cork&EPDM and cork&NBR seals provide excellent sealing in a 100% hydrogen environment.

Seals play a crucial role in sealing hydrogen technologies, since even small leaks can pose significant safety risks and cause operational inefficiencies. The test results confirm the reliability of these materials for storing and transporting hydrogen, highlighting their potential for maintaining safety and efficiency in hydrogen-rich environments.

These successful tests represent a further advance by Amorim Cork Composites in the development of sustainable cork solutions for hydrogen sealing. Future tests could broaden these conclusions by evaluating new materials and testing under varying temperature and pressure conditions, simulating even more extreme operating environments commonly found in industrial hydrogen applications.