Japan – ClassNK has granted approval in principle (AiP) for a dual-fuel generator engine using hydrogen gas as fuel for a 160,000 cubic meter (cbm) liquid hydrogen carrier developed by Kawasaki Heavy Industries (KHI).
KHI claims that the dual-fuel generator engine can switch between using hydrogen and low-sulfur fuel oil (LSFO). When hydrogen fuel is selected, boil-off gas that naturally evaporates from the ship’s liquefied hydrogen cargo tanks is used as the primary fuel to generate and supply electricity on board at a calorie-based mixed ratio of 95% or higher. This is expected to significantly reduce the ship’s emissions of greenhouse gases.
This was the classification group’s first AiP for a dual-fuel generator engine employing hydrogen gas as fuel, the statement says.
The KHI liquid hydrogen carrier’s integrated design, including its cargo handling system, cargo containment system, and twin fuel main boilers that burn hydrogen boil-off gas as fuel, have all been awarded AiPs by ClassNK.
ClassNK performed the design review of the dual fuel generator engines using hydrogen gas as fuel and related machinery systems and arrangements in the most recent examination based on its Part N of Rules for the Survey and Construction of Steel Ships incorporating the IGC Code and its Guidelines for Liquefied Hydrogen Carriers incorporating the IMO’s interim recommendations for Carriage of Liquefied Hydrogen in Bulk. Based on the results of the HAZID risk assessment, a complete safety examination was conducted before the AiP was released.