Swedish marine technology company Alfa Laval has secured Approval in Principle (AiP) from Norway-based classification society DNV for its gas combustion unit (GCU) technology for hydrogen boil-off gas. This will allow the company to use GCU on liquid hydrogen carriers, marking a ‘key step toward safer transportation’ of this fuel.
According to a statement from Alfa Laval, receiving DNV’s AiP represents a ‘major accomplishment’ for the company’s hydrogen GCU design as it should clear the path toward the development of a GCU prototype. The protype would undergo additional testing and type approval to create a ‘safe and efficient system’ for managing boil-off gas on liquid hydrogen carriers.
“The AiP for our GCU design is a significant achievement for us. It demonstrates that our concept has been assessed with respect to DNV’s classification rules and adheres to established technical and safety standards,” David Jung , Business Development Manager, Alfa Laval, highlighted.
The new solution is based on Alfa Laval’s existing LNG GCU technology . In 2022, the company informed that in just over a decade, more than 200 of these units have been installed, while an additional 100 were reportedly ordered—the same year when Alfa Laval signed a Memorandum of Understanding (MoU) with Shell International Trading and Shipping Company Limited.
Under the MoU, Alfa Laval was to develop a system to safely combust hydrogen boil-off gas from a vessel’s storage tank, as part of a new liquid hydrogen carrier.
Nonetheless, the adoption of hydrogen as a marine fuel presents distinct challenges. For instance, despite being an attractive alternative fuel, hydrogen possesses certain limitations with deep-sea vessels, causing it to lag behind methanol and ammonia.
Additionally, when it comes to hydrogen transportation at sea, this has proven to be far more complex compared to liquefied natural gas. This is largely due to hydrogen’s extremely low boiling point of -253°C, which results in a higher boil-off rate during transport. Its properties—being light, highly flammable, and easily ignitable—demand stringent safety measures.
Managing boil-off gas is crucial for liquid hydrogen carriers due to restrictions on venting cargo. As per Alfa Laval, this could make GCU technology necessary to maintain safe tank conditions by controlling pressure and temperature, allowing for the secure combustion of hydrogen boil-off gas from the vessel’s storage tank.
“For the industry to confidently transport hydrogen, ensuring the safety and reliability of enabling technologies is paramount,” David Jung emphasized.
“Alfa Laval’s experience in gas combustion technology for LNG carriers positions us well for GCU technology once the hydrogen transportation market takes off.”