BOG solution for LH2 carrier design receives AiP
HD Korea Shipbuilding & Offshore Engineering (HD KSOE) was awarded an approval in principle (AiP) from DNV for a ‘hydrogen system’ related to a liquefied hydrogen-fuelled gas carrier design concept at Gastech 2023 in Singapore. The AiP was also awarded to HD KSOE’s subsidiaries HD Hyundai Heavy Industry (HD HHI) and Hyundai Mipo Dockyard (HMD) for the new hydrogen system.
The new system utilises boil-off gas (BOG) from the transportation of liquefied hydrogen to power a hybrid propulsion system, integrating hydrogen dual-fuel engines and fuel cells.
The Motorship notes that the ability to safely transport large volumes of hydrogen in liquefied form at -253°C (only 20°C above absolute zero) is one of the major technological challenges that the project partners aim to overcome to ensure a reliable, efficient, safe and competitive global carbon-free hydrogen value chain. The lighter weight of LH2 means sloshing will not mimic the behaviour of LNG, with consequences for efforts to align the system’s boil-off rate with the gas handling capacities on board the vessel.
The Motorship notes that the use of fuel cells to power the LH2 carrier would consume the boil-off, but the project addresses a challenge for LH2 carriers, which is to design fuel cells that meet the power demand of the vessels. By combining the fuel cells with dual-fuel engines, the solution will allow the boil-off gas to be consumed in the propulsion system, with a reliquefaction system handling the excess.