Nippon Kaiji Kyokai (ClassNK), along with consortium partners NYK Line, IHI Power Systems, Nihon Shipyard and Japan Engine Corporation J-Eng), have announced that a four-stroke ammonia-fuelled engine has successfully completed a land-based test for the stable combustion of fuel ammonia having an 80% co-firing ratio as part of a demonstration project for the commercialisation of vessels equipped with a domestically produced ammonia-fuelled engine.
This is believed to be the world’s first such test. The initiative concerns the development of vessels equipped with a domestically produced ammonia-fuelled engine. It was initiated in October 2021 by NYK, J-Eng, IHI Power Systems, and Nihon Shipyard as part of the Green Innovation Fund Project of Japan’s New Energy and Industrial Technology Development Organization (NEDO).
In April 2023, IHI Power Systems commenced operational tests at its Ota plant on a 280mm bore four-stroke ammonia-fuelled marine engine to be used as the main engine in coastal vessels and tugs.
Ammonia does not emit CO2 during combustion and is therefore expected to be a next-generation fuel that contributes to combating global warming, but it is a difficult substance to handle due to its toxicity. This time, while thoroughly ensuring safety, a test increased the mixing ratio of fuel ammonia within the engine to 80%, and tests were conducted on the exhaust gas aftertreatment devices and fuel supply systems, and the stable integrated operation of these systems was successfully achieved for the first time.
The tests confirmed that emissions of dinitrogen monoxide (N2O), which has a greenhouse effect about 300 times greater than CO2, and unburnt ammonia were virtually zero, and there was no ammonia leakage from all demonstration equipment during operation and after shutdown.
Prior to the test, a demonstration equipment inspection and technical review meeting were held oat IHI Power Systems’ Ota plant by NYK, IHI Power Systems, Nihon Shipyard, and ClassNK. Keihin Dock Co, which is responsible for the conversion of a tug (known as the A-Tug) to ammonia fuel, and Shin-Nippon Kaiyosha, which is responsible for the operation and management of the vessel, participated in an inspection of the demonstration equipment to confirm the technologies involved in its construction and operation.
The engine will be installed in the A-Tug, which will be completed in June 2024, after further land-based testing of the engine to maximise GHG reductions through further improvement of the co-firing rate. Furthermore, based on this research and development for domestic vessels, efforts will be made to develop a 250mm bore engine for the auxiliary engine of an oceangoing vessel. That auxiliary engine will be installed on an ammonia-fuelled ammonia gas carrier scheduled for delivery in October 2026, under joint development by NYK, Nihon Shipyard, J-Eng, IHI Power Systems, and ClassNK.
Following the success of this demonstration test, the consortium will continue to work together to strengthen the international competitiveness of the Japan maritime cluster, with the aim of building the world’s first ammonia-fuelled ships and achieving safe navigation, including by contributing to the development of international rules.