Everllence has announced that its 21/31 dual-fuel engine has successfully operated on ethanol across all load points during tests at its Frederikshavn facilities in Denmark.

The Germany-based company noted that this development allows it to demonstrate the use of ethanol as a viable fuel in its engine platform.

The 21/31 engine is part of Everllence’s ongoing work in alternative fuel technologies.

The company previously introduced two-stroke methanol-burning engines, with the first commercial unit entering service in 2016.

In 2024, Everllence launched the 21/31DF-M, a small-bore, four-stroke, methanol-burning generator set, which is now in commercial use.

Everllence Marine GenSets sales and promotion director Lars Zimmermann 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. Our position as the world’s leading engine designer means that we have a special, on-going obligation to develop new technologies to decarbonise the global maritime industry.”

According to Everllence, the latest tests with ethanol build on the existing 21/31 engine platform.

The company said the successful operation on ethanol provides a fully operational engine for documenting the fuel’s capabilities.

Everllence four-stroke small-bore engineering head and senior manager Rasmus Frimann Nielsen 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. 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.”

In November 2025, Everllence introduced its new dual-fuel ME-LGIA (Liquid Gas Injection Ammonia) two-stroke engine to the maritime sector.

The ME-LGIA engine combines the Diesel principle with dual-fuel liquid gas injection technology.