Maritime Consortium successfully completes ammonia co-firing test with ammonia-fuelled engine


A consortium of NYK Line, IHI Power Systems, Nihon Shipyard, Japan Engine Corporation and Nippon Kaiji Kyokai (ClassNK) is pleased to announce that the world’s first 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 commercialization of vessels equipped with a domestically produced ammonia-fuelled engine.

This initiative concerns the development of vessels equipped with a domestically produced ammonia-fuelled engine. It was initiated in October 2021 by NYK, Japan Engine Corporation, IHI Power Systems, and Nihon Shipyard as part of the Green Innovation Fund Project of the New Energy and Industrial Technology Development Organization (NEDO).

In April 2023, IHI Power Systems commenced operational tests at its Ota plant (Gunma Prefecture) on a 280 mm bore four-stroke ammonia-fuelled marine engine for the main engine of coastal vessels – such as the proposed A-Tug tugboat design.

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, etc., and the stable integrated operation of these systems was successfully achieved for the first time.

The tests also confirmed that emissions of dinitrogen monoxide (N2O), which has a greenhouse effect about 300 times greater than carbon dioxide (CO2), and unburnt ammonia were virtually zero, and there was no ammonia leakage from all demonstration equipment during operation and after shutdown.