Mitsui E&S Co., Ltd. has announced the commercialisation of large ammonia-fuelled marine engines and ammonia fuel supply systems (AFSS), positioning itself as the only company in Japan manufacturing both products, according to the Tokyo-headquartered company.

The announcement follows land-based testing conducted in February 2026, in which the company ran its ammonia dual-fuel engine — the Mitsui-Everllence B&W 7S60ME-C10.5-LGIA-HPSCR — and its AFSS in integrated operation in the presence of classification society ClassNK (Nippon Kaiji Kyokai). The tests were said to have verified the performance of both systems, confirmed compliance with classification society rules for onshore testing, and received NOx certification in line with International Maritime Organization (IMO) NOx regulations.

With commercialisation now declared complete, Mitsui E&S says it is able to supply the engine and AFSS as an integrated package for use in actual vessels.

Ammonia is considered a candidate next-generation marine fuel owing to the absence of carbon dioxide emissions during combustion. However, the company acknowledged that ammonia presents technical challenges, noting that it is difficult to ignite and carries risks related to toxicity and corrosiveness.

Mitsui E&S also announced plans to expand its land-based testing facilities for AFSS compatible with both Everllence- and WinGD-licensed engines, alongside the establishment of a mass production system for both engines and AFSS in anticipation of rising demand.

The development of the AFSS was carried out under the 'Integrated Project for the Development and Social Implementation of Ammonia-Fuelled Ships,' supported by the Green Innovation Fund of Japan’s New Energy and Industrial Technology Development Organization (NEDO). The expansion of the AFSS for onshore testing was supported through the 'Project to Promote the Construction of Zero-Emission Ships,' a joint initiative of Japan’s Ministry of the Environment and the Ministry of Land, Infrastructure, Transport and Tourism.