Mitsui O.S.K. Lines, Ltd. (MOL) has announced that a large-size ammonia-powered carrier, which has been under joint development by MOL, Namura Shipbuilding Co., Ltd., and Mitsubishi Shipbuilding Co., Ltd. since 2021, has received Nippon Kaiji Kyokai (ClassNK) approval in principle (AiP) for its ammonia fuel-compatible design.

The companies are developing the vessel in anticipation of the wide use of ammonia as a zero-carbon fuel and hydrogen carrier and in response to further demand for ammonia fuel transitions in power plants.

MOL said in the announcement that the carrier features larger cargo tanks than very large gas carriers (VLGCs) and very large ammonia carriers (VLACs), enabling low-emission transport and higher cargo capacity while also using ammonia as fuel.

"In particular, it is a groundbreaking vessel in that it meets the restrictions on entry into major power plants in Japan while maintaining specifications consistent with current VLGCs in terms of connections to power plants and ammonia supply terminals during loading and discharging," the Japanese shipping company said.

It noted that ClassNK reviewed the basic plans and results of the hazard identification study (HAZID), which are reflected in the basic design allowing for the completion of the detailed design. In HAZID, the safety of ammonia toxicity, which is a major concern, was studied and evaluated as a top priority, and sufficient countermeasures have been implemented in the design.

The MOL Group aims to achieve net zero greenhouse gas (GHG) emissions by 2050 and will continue to work toward a decarbonized, low-carbon society in accordance with BLUE ACTION 2035 and MOL Group Environmental Vision 2.2.

AiP is granted based on risk assessments conducted by experts in new technologies or areas where existing regulations lack specific details. This certification indicates the completion of a feasibility study on a basic design that incorporates this technology and concept, ensuring a smooth transition to a detailed design.

In this case, the assessment was not limited to a feasibility study; based on the basic design, the detailed design was completed.