Japan: J-ENG begins co-firing of first full-scale marine engine with ammonia

Japan Engine Corporation (J-ENG) on Monday (21 April) said the first Japanese-developed and manufactured commercial full-scale, low-speed, ammonia-fuelled two-stroke engine has started co-firing operation with ammonia, which will be installed in a vessel. 

J-ENG is developing the engine under the “Green Innovation Fund Project: Next-generation Ship Development” of the New Energy and Industrial Technology Development Organization (NEDO). 

Since May 2023, when J-ENG started the world’s first ammonia co-firing operation of a large, low-speed, two-stroke engine in a test engine, J-ENG has obtained many results and knowledge, including stable operation at high ammonia co-firing rates and safe handling of ammonia, through various test operations over a period of about a year and a half. 

J-ENG will conduct verification operations on the full-scale engine and plans to ship the engine in October of this year. The engine will be installed on an Ammonia-fuelled Medium Gas Carrier (AFMGC) and then demonstration operations of the vessel will be carried out then.

In order to accommodate a wide variety of ammonia-fueled vessels, J-ENG is also concurrently developing an ammonia-fueled engine with a cylinder bore of 60cm, following the first engine with a 50cm cylinder bore mentioned above, for several promising follow-on projects.

Furthermore, after achieving the development and social implementation of these engines, the company has decided to construct a new plant with the support of a subsidy project by the Ministry of the Environment and the Ministry of Land, Infrastructure, Transport and Tourism through the GX Economic Transition Bonds. 

The new plant, which is scheduled for completion in 2028, will expand the production of ammonia fuel engines (in the product mix with fuel oil engines) and promote the spread and expansion of zero-emission ships.

“J-ENG, as a first mover of next-generation fuel engines, will contribute to the development of the Japanese shipping and shipbuilding industries through the early launch and expansion of these engines, and at the same time, contribute to the reduction of greenhouse gases (GHG) in international shipping and the achievement of carbon neutrality by 2050,” the company said on its website.

Photo credit: Japan Engine Corporation
Published: 23 April, 2025