ClassNK approves Daihatsu’s LPG-fueled vessel design

Japan’s classification society ClassNK granted an approval in principle (AiP) to Daihatsu Diesel for their concept design of an LPG reformed gas-fueled coastal LPG carrier.

The vessel is developed in cooperation with Iino Gas Transport, Osaka Gas, Izumi Steel Works, and Miura Shipbuilding in terms of safety assessments.

The AiP is based on ClassNK’s rule Part N which adopts IGC Code and its Guidelines for Ships Using Low-Flashpoint Fuels.

The vessel is designed to be equipped with an LPG reformer developed jointly by Daihatsu Diesel and Osaka Gas, and a dual fuel engine developed by Daihatsu Diesel. The LPG Reformer is designed to convert LPG into synthetic methane gas equivalent to the kind found in LNG.

Due to being mainly composed of propane and butane, LPG is susceptible to knocking (abnormal combustion), making it difficult to use as a fuel for lean-burn gas engines and dual-fuel engines. In contrast, by converting LPG into synthetic methane gas with the LPG Reformer prior to fueling the engine, the risks of knocking can be restrained, which is expected to have an equivalent operational performance observed when using LNG.

Speaking on the occasion, ClassNK senior executive vice president T. Shigemi said, “LPG is starting to become an option in the maritime industry and we have high expectations for the possible benefits that its use may bring in terms of environmental safety and efficiency.”