Japan Engine Corporation (J-ENG) launched the 7UEC50LSJA-HPSCR on August 30, marking the debut of the world’s first fully functional, full-scale commercial ammonia-powered ship engine. The Akashi-based company is the only global licensor of marine low-speed diesel engines.
The dual-fuel engine, developed by J-ENG, is designed to power a cargo vessel in 2026, aiming for near-zero emissions. The engine’s development aligns with the “Next-Generation Ship Development” program under the Green Innovation Fund Project. This project is administered by the New Energy and Industrial Technology Development Organization (NEDO).
Data from trials indicated significant emission reductions. At 100 percent load and 95 percent ammonia co-firing, the engine produced only three parts per million (ppm) of nitrous oxide (N₂O). This level represents a reduction of over 90 percent in greenhouse gas emissions. Nitrogen oxide (NOx) emissions were also halved compared to conventional oil engines, while unburned ammonia emissions were virtually eliminated using advanced aftertreatment systems.
According to J-ENG representatives, this achievement follows extensive testing conducted between May 2023 and September 2024. Over 1,000 hours of testing were performed on a single-cylinder ammonia prototype at the Mitsubishi Heavy Industries R&D Center in Nagasaki. The prototype featured a seven-cylinder design with a six-inch bore.
The engine incorporates a high-pressure selective catalytic reduction (SCR) system. This system utilizes a catalyst and an ammonia-based reducing agent, such as urea, to decrease nitrogen emissions. Urea decomposes into ammonia within the system. The engine successfully passed performance verification trials in both fuel modes, leading to official certification by ClassNK, the world’s largest class society, for exceptional environmental performance and operational safety.
Official performance tests occurred at J-ENG’s facility, supervised by representatives from several industry entities. These included NYK Line, Nihon Shipyard, Japan Marine United Corporation (JMU), and ClassNK. J-ENG conveyed pride in delivering a safe and reliable engine ahead of global competitors, a result of a meticulously planned, long-term development program. The company stated, “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.”
J-ENG also emphasized its commitment to advancing the shipping and shipbuilding industries in Japan. The company concluded in a press release that it will promote the early market introduction and widespread adoption of these engines. J-ENG aims to decrease greenhouse gas (GHG) emissions in the shipping industry and realize carbon neutrality by 2050, stating,
“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.”
