Japanese consortium completes land-based NH3-fuelled engine tests

The demonstration project represents a step towards the commercialisation of a four-stroke ammonia-fuelled engine. The first installation of a four-stroke ammonia-fuelled engine as a main mover is expected to be completed in June 2024 on board an ammonia-fuelled tug (A-Tug), which will be completed in June 2024, after further land-based testing of the engine to maximise greenhouse gas (GHG) reductions through further improvement of the co-firing rate. 

The project partners announced that they are also seeking to develop a 250 mm bore engine for the auxiliary engine of a deep-sea vessel. That auxiliary engine will be installed on an ammonia-fuelled ammonia gas carrier (AFAGC, scheduled for delivery in October 2026) under joint development by NYK, Nihon Shipyard, Japan Engine, IHI Power Systems, and ClassNK. 

Project background

In October 2021, NYK, J-ENG, IHI Power Systems, and Nihon Shipyard launched a development project to produce vessels equipped with a Japanese-produced ammonia-fuelled engine. The project received funding from Japan’s New Energy and Industrial Technology Development Organization (NEDO) as part of its Green Innovation Fund Project.

In April 2023, IHI Power Systems commenced operational tests at its Ota plant (Gunma Prefecture) on a 280 mm bore** four-stroke ammonia-fueled marine engine for the main engine of coastal vessels (i.e., ammonia-fueled tugboats, hereafter “A-Tug”).

The project has also conducted tests 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 nitrous oxide (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.

Prior to the test, a demonstration equipment inspection and technical review meeting were held on 11 April at IHI Power Systems’ Ota plant by NYK, IHI Power Systems, Nihon Shipyard, and ClassNK. Keihin Dock Co., Ltd., which is responsible for the conversion of the A-Tug, and Shin-Nippon Kaiyosha, which is responsible for the operation and management of the vessel, also participated in the inspection of the demonstration equipment to confirm the technologies involved in its construction and operation.