NYK Line, IHI Power Systems Co., Ltd. (IHI Power Systems), Nihon Shipyard Co., Ltd. (Nihon Shipyard), Japan Engine Corporation, and Nippon Kaiji Kyokai (ClassNK) have collaborated on the successful completion of land-based testing of the world’s first four-stroke ammonia-fueled engine. The engine underwent a test for stable fuel ammonia combustion at an 80% co-firing ratio as part of a demonstration project for the commercialization of vessels equipped with domestically produced ammonia-fueled engines. This landmark initiative started in October 2021 as part of the Green Innovation Fund Project by NYK, Japan Engine Corporation, IHI Power Systems, and Nihon Shipyard.
A 280mm bore four-stroke ammonia-fueled marine engine was initiated at IHI Power Systems’ Ota plant (Gunma Prefecture) in April 2023 for operational tests. The engine will be the main engine of coastal vessels such as ammonia-fueled tugboats (A-Tug). Ammonia, unlike other fuels, does not release CO2 during the combustion process and is expected to be the next-generation fuel that battles global warming. However, ammonia is hazardous to handle due to its toxicity. Therefore, while maintaining safety, the tests increased the fuel ammonia mixing ratio within the engine to 80%. The tests included the exhaust gas aftertreatment devices and fuel supply systems, and the successful integrated operation of all these systems was achieved for the first time.
During the tests, there was virtually no emission of dinitrogen monoxide (N2O) and unburnt ammonia, and there was no ammonia leakage from any of the demonstration equipment during operation or after shutdown. Before the tests, there was a demonstration equipment inspection and technical review meeting held at IHI Power Systems’ Ota plant on the 11th of April. NYK, IHI Power Systems, Nihon Shipyard, and ClassNK were in attendance, as were Keihin Dock Co., Ltd., responsible for the conversion of the A-Tug, and Shin-Nippon Kaiyosha, the company in charge of the vessel’s operation and management.
The engine will be installed on A-Tug, scheduled for completion in June 2024, after further land-based testing of the engine to maximize greenhouse gas (GHG) reductions through co-firing rate improvement. Efforts will also be made to develop a 250mm bore engine for the auxiliary engine of an oceangoing vessel, which will run on ammonia fuel. The auxiliary engine will be installed on an ammonia-fueled ammonia gas carrier (AFAGC), which is under joint development by the five consortium partners.
The consortium’s goal is to build and navigate the world’s first ammonia-fueled ships. Furthermore, the consortium aims to strengthen the international competitiveness of Japan’s maritime cluster and contribute to the development of international regulations, starting with the success of this demonstration test.