Everllence, formerly known as MAN Energy Solutions, has confirmed that its 21/31 dual-fuel engine successfully ran on ethanol across the full load range during recent tests conducted in Frederikshavn, Denmark. The company said the results further demonstrate the platform’s ability to accommodate alternative fuels, adding to earlier work on methanol for the same engine family.

Everllence has built on more than a decade of experience with methanol technologies, having introduced the first commercial two-stroke methanol engine in 2016 and later launching the small-bore, four-stroke 21/31DF-M genset in 2024. Several units of the methanol-capable model are already in commercial operation, and the latest tests expand the platform’s potential fuel options.

Rasmus Frimann Nielsen, senior manager and head of four-stroke small-bore engineering at Everllence, said: "This engine platform has shown great promise when burning alternative fuels and, during testing, we even managed to expand the ethanol fuel-share compared with methanol. In general, the past few years have seen steadily growing interest in ethanol from the market."

Nielsen added: "We always do our utmost to listen to these signals and had accordingly been carrying out the necessary design considerations, which has provided us with a solid technical foundation. Tests in Frederikshavn have now provided us with the technical know-how to take us to the next level."

The company said it is still evaluating test data but confirmed its earlier assumption that the 21/31 engine can run on ethanol without issues.

Lars Zimmermann, director of sales and promotion for marine gensets at Everllence, said: "We keep a close eye on the market and see some uncertainty among our customers regarding which fuel strategy they should pursue. In response, Everllence has pioneered many fuel-flexible solutions with ethanol on the 21/31 platform, just the latest."

Zimmermann called for legislation that recognises ethanol as a viable fuel source, as well as for the development of the requisite market demand.

Headquartered in Germany, Everllence operates at more than 140 locations worldwide and provides propulsion, decarbonisation and efficiency technologies for the maritime, energy and industrial sectors.