Danish company Everfuel — which produces and distributes green hydrogen, and operates nine H2 refuelling stations — has halted all distribution of its fuel after a leak was discovered in one of its truck trailers.

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The malfunction occurred on 10 June during operations in the Netherlands, although Everfuel stresses in a statement that this took place “within the fenced perimeter of the hydrogen station and posed no risk to people or the environment”.

An initial investigative report indicates that the source of the leak was a faulty valve and did not exclude the possibility that it was a systemic problem.

As such, Everfuel has decided to halt usage of its 12 hydrogen trailers — all supplied by Norwegian firm Hexagon Purus — “until all relevant valves have been controlled”.

“Everfuel is in close dialogue with the supplier of the hydrogen trailers to identify the root cause and ensure that corrective measures are implemented in accordance with supplier protocol and Everfuel safety requirements,” the statement continues.

The truck trailers in question contain multiple compressed-hydrogen cylinders. Photo: Hexagon Purus

“The grounding of the trailer fleet will have a negative impact on the distribution of hydrogen to Everfuel’s customers and refuelling stations.

“The company is working to minimise the implications for customers and end-users and will provide further updates when available.”

Everfuel currently operates five hydrogen refuelling stations in Denmark, two in the Netherlands and two in Norway.

Hexagon Purus has previously stated that its Type 4 composite compressed-hydrogen cylinders — which it says are used in Everfuel trailers — “are subjected to various simulated and real load tests” before entering operation.

“The Type 4 composite cylinders have to pass around 15 highly demanding mechanical, chemical and thermal load tests during homologation. After successful approval, each finished distribution system is leak-tested and inspected and approved by a notifying body prior to shipment,” it added.

Hydrogen Insight has contacted Everfuel and Hexagon Purus for further comment, including confirmation on whether vented hydrogen was released into the atmosphere — where studies suggest it could be a potent indirect greenhouse gas.

Peter Gerstl, European commercial director for hydrogen at industrial gas equipment company Chart Industries, told Hydrogen Insight that while regulations preclude H2 from being vented as part of regular operation, it can be released as an emergency due to pressure build-up.

And while vented hydrogen can be “re-routed to the trailer”, Gerstl says that if the customer has specified “7.0” purity — which needs to be 99.9999999% pure and is typically used by the chemicals, pharmaceuticals and semiconductor industries — there cannot be “a backward flow of molecules” due to the risk of contamination.

This means that to keep hydrogen pure, if there is a pressure build-up, it must be released into the atmosphere — although Gerstl adds that for lower purities, such as 5.0 often used in fuel cells, it should be “no problem at all to recycle” the vented H2.