Japan's First! Development and Commercialization of Large-Scale Ammonia Co-firing Engine ～Co-firing Rate Exceeding 50% - New Product for Marine and Power Generation Contributing to Decarbonization～

20 November 2025
JFE Engineering Corporation

JFE Engineering Corporation (President: Kazumi Fukuda, Head Office: Chiyoda-ku, Tokyo) is pleased to announce that we have successfully tested Japan's first^*1 large-scale medium-speed dual-fuel engine capable of co-firing ammonia, a carbon-neutral fuel, with diesel oil, and have commenced sales.

We have been developing ammonia co-firing technology based on the 4 stroke PC2.6B CR ^*2 diesel S.E.M.T. Pielstick engine from Everllence France^*3 (formerly MAN Energy Solutions France). Through ammonia co-firing demonstration tests with diesel oil using a 3-cylinder test engine achieved with the support of Everllence France, we have commercialized a large-scale medium-speed dual-fuel engine exceeding 7MW^*4. This engine could be converted to achieve a practical ammonia co-firing rate of 50% (thermal ratio) for social implementation, when the serial version of the ammonia co-firing kit for PC2.6B CR will be released in the near future.

This engine has been tested with a retrofit^*5 concept, allowing for conversion from diesel oil-only operation^*6 to ammonia co-firing with minimal modifications. This enables operation as a diesel oil-only engine at the time of delivery, with specification conversion to ammonia co-firing when a stable ammonia supply becomes available. Additionally, as a dual-fuel engine, it can switch operating modes between ammonia co-firing and diesel oil-only operation according to circumstances, enabling more flexible operation.

While ammonia fuel enables CO₂ reduction through direct combustion, technical challenges include reducing unburned ammonia (NH₃) due to its flame-resistant properties, suppressing nitrous oxide (N₂O) which has high global warming potential and is generated as a combustion characteristic, controlling nitrogen oxides (NO_x) which are harmful substances generated from nitrogen in the fuel, and improving thermal efficiency.

We conducted numerical analysis research on ammonia combustion and reflected these research results in demonstration tests to solve these challenges. Furthermore, by using exhaust gas treatment catalysts in combination, we succeeded in virtually eliminating unburned ammonia emissions and minimizing N₂O and NO_x. Additionally, we achieved 85% output compared to diesel-only operation and obtained thermal efficiency equivalent to diesel-only operation.

Initially, we will sell these engines as power generation equipment for isolated island power plants and other applications where decarbonization methods are limited. In line with market trends, we plan to obtain the necessary class certifications for marine engines and intend to sell for both marine and power generation applications. We will also continue to conduct demonstration tests to further increase the ammonia co-firing rate in response to market demand, with commercialization at an 80% co-firing rate in our sights.

Leveraging our many years of expertise in diesel engine and dual-fuel engine development, we will continue to make significant contributions to our customers' carbon neutrality initiatives.

Leveraging our many years of expertise in diesel engine and dual-fuel engine development, we will continue to make significant contributions to our customers' carbon neutrality initiatives.

• *1 According to our company's research
• *2 Product Introduction: JFE Diesel Engine PC2.6 B / PC2.6 B CR
  Products JFE Diesel Engine PC2.6B/ PC2.6B CR
  PC2.6B CR is a licensed engine jointly developed by Everllence France and JFE.
• *3 Company name changed from MAN Energy Solutions to Everllence SE in June 2025 (Head Office: Augsburg, Germany)
  Everllence France is part of Everllence SE, a German group with extensive achievements in marine equipment and power generation facilities
• *4 Output covers 7.7MW to 11.5MW
• *5 Term referring to updating and improving existing equipment with new technology or parts.
• *6 PC2.6B CR: common rail electronic fuel injection specification engine compatible with retrofit.

Ammonia Co-firing Engine / Demonstration Test Facilitｙ

Ammonia Co-firing Engine Base Machine / Co-firing Method