German engine manufacturer Everllence—formerly known as MAN—has successfully completed tests of its 21/31 dual-fuel engine operating on ethanol at its test facility in Frederikshavn.
In 2024, the company became the first engine maker to introduce a small-bore, four-stroke methanol engine, the 21/31DF-M, with several units already in commercial service. Building on the 21/31 platform, Everllence has now finalized ethanol trials, resulting in a fully functional engine that can be used to document and demonstrate ethanol’s potential as a marine fuel.
Rasmus Freeman Nielsen, Senior Manager and Head of Engineering for small-bore four-stroke engines at Everllence, said the platform has shown strong promise with alternative fuels. He noted that during the test program the team was able to increase the ethanol share in the fuel blend compared with methanol testing, and that market interest in ethanol has been rising steadily in recent years. While data analysis is still ongoing, he added that the initial results support earlier expectations that the 21/31 engine can operate on ethanol without major issues.
Lars Zimmermann, Director of Sales and Promotion for marine gensets at Everllence, emphasized that developing new technologies is part of the company’s responsibility as a leading engine developer supporting shipping decarbonization. He added that wider deployment will require regulation that recognizes ethanol as a viable marine fuel, along with policies and market mechanisms that help create sufficient demand.
