Japan Engine Corporation (J-ENG) has launched the world’s first fully-functional, full-scale commercial ammonia-powered ship engine, model 7UEC50LSJA-HPSCR, on August 30, promising near-zero emissions and set to power a cargo vessel in 2026.
The dual-fuel engine, developed by J-ENG, is part of the ‘Next-Generation Ship Development’ under the Green Innovation Fund Project administered by NEDO. This achievement followed over 1,000 hours of testing on a single-cylinder ammonia prototype from May 2023 to September 2024 at the Mitsubishi Heavy Industries R&D Center in Nagasaki. The prototype featured a 6-inch (50 centimeters) bore, seven-cylinder design incorporating a high-pressure SCR (selective catalytic reduction) system that uses an ammonia-based reducing agent to curtail nitrogen emissions.
The engine underwent official performance tests at J-ENG’s facility, supervised by industry partners including NYK Line, Nihon Shipyard, Japan Marine United Corporation (JMU), and ClassNK. Following extensive performance verification trials in both fuel modes, the engine was officially certified by ClassNK for its outstanding environmental performance and operational safety.
Trial data indicated that at 100 percent load and 95 percent ammonia co-firing, the engine produced only three ppm of nitrous oxide (N₂O), which translates to a reduction of more than 90 percent in greenhouse gas emissions. Furthermore, nitrogen oxide (NOx) emissions were halved compared to conventional oil engines, and unburned ammonia emissions were virtually zero, attributed to advanced aftertreatment systems.
“J-ENG is extremely pleased and proud to be able to deliver to customers ahead of the rest of the world this safe and reliable engine, the result of a meticulously planned, long‑term development program that accumulated extensive operational data over an extended period,” the company revealed in a press release.
J-ENG also stated, “As a first mover in next-generation fuel engines, J-ENG will contribute to the development of Japan’s shipping and shipbuilding industries by promoting the early market introduction and widespread adoption of those engines, while also contributing to the reduction of GHG (greenhouse gas) emissions in the shipping industry and the realization of carbon neutrality by 2050.”
