The NAMOSYN consortium set out to create a foundation for the introduction of synthetic fuels that can be produced sustainably while meeting ecological, economic and societal criteria. Within this framework, Motorenfabrik Hatz GmbH & Co. KG (HATZ) focused on the use of oxymethylene ether (OME, n = 1–6) as a diesel‑compatible fuel for small off‑highway and industrial engines. The project, carried out from 1 April 2019 to 30 September 2022, was funded by the German Federal Ministry of Education and Research under the Basic Research Energy programme for Sustainable Mobility with Synthetic Fuels (grant 03SF0566M0). HATZ worked in close collaboration with other partners in the NAMOSYN consortium and the research cluster FC 1A “OME for diesel engines – motor behaviour”.

Technically, the study demonstrated that OME burns without soot due to its high oxygen content and absence of C–C bonds, resulting in particulate emissions that are comparable to ambient air levels. The combustion of OME also allows for high after‑treatment recirculation (AGR) rates without the typical NOx penalties, yielding low NOx emissions. Because OME has a lower heating value than conventional diesel, the volumetric fuel flow must be increased by a factor of approximately 1.7, a requirement that was met by adapting the engine’s fuel system. Modifications included new pistons, a redesigned cylinder head, an injection pump and injector capable of handling the higher flow, a magnet valve, a multi‑chamber tank system, and a virtual sensor for real‑time fuel detection. The robustness of OME combustion to variations in injection strategy reduced the sensitivity of the engine to tuning, simplifying retrofit procedures. The fuel’s low volatility and biodegradability, combined with a low hazard potential, further support its suitability for widespread use.

The project validated an energy‑efficient, environmentally friendly flex‑fuel combustion strategy for a 1‑cylinder industrial diesel engine. An electronically controlled engine served as the enabling technology, allowing for a digital, geo‑position‑dependent automatic switching between diesel and OME. This approach ensures that the engine operates on the most appropriate fuel for the prevailing emission regulations, particularly in urban areas with stringent air‑quality standards. Field tests confirmed that the adapted engine met all relevant emission limits while maintaining performance and reliability. The thermodynamic flex‑fuel strategy proved capable of delivering diesel‑like power output when required, while switching to OME to achieve the lowest possible emissions during other operating conditions.

Collaboration was a key element of the project. HATZ coordinated the engineering and testing activities, while partners from academia and industry contributed expertise in fuel chemistry, engine dynamics, and digital control systems. The consortium structure facilitated the integration of component adaptations, digital control algorithms, and field‑test protocols. The partnership with the German Federal Ministry of Education and Research provided the necessary funding and strategic guidance, ensuring that the project aligned with national sustainability goals. Through joint workshops, data exchanges, and shared test facilities, the consortium advanced the technical knowledge required to bring synthetic fuels like OME from laboratory research to practical, real‑world applications. The outcomes of this collaboration lay the groundwork for future projects aimed at scaling up synthetic fuel use across a broader range of vehicle types and operating environments.