With synthetic diesel fuels of the EN15940 standard, CO2 emissions can be reduced by up to 100% compared to fossil diesel. Hydrotreated vegetable oil (HVO or renewable diesel), which is already commercially available today, reduces CO2 emissions by up to 90%. If the fuels are produced with the help of renewable energy and green hydrogen – through what is termed a power-to-X process – existing rail vehicles can be operated in a completely CO2-neutral manner.
The mtu Series 1800 engines which are used in mtu PowerPacks, as well as Series 1300 and 1500 for locomotives and multi-purpose vehicles, are already approved for use with synthetic fuels such as HVO. Series 1600 and versions of Series 4000 engines will follow soon.
The release of engines for climate-friendly fuels requires a series of tests and trials and Rolls-Royce has found strong partners for this activity. DB Cargo and RDC Autozug Sylt have already tested or are currently testing mtu Series 4000 engines with HVO in their locomotives.
Jürgen Blassmann, director of rail business at Rolls-Royce’s business unit Power Systems, said: “HVO allows our customers to significantly reduce their greenhouse gas emissions with existing vehicles and engines and to make an important contribution to climate protection today. Emissions of soot and nitrogen oxide are also significantly reduced – without having to make any changes to the drive system or infrastructure. No significant changes in performance were observed and availability and service life of our engines remain unchanged, which is highly attractive for our customers.
“In combination with our mtu Hybrid PowerPack, HVO allows not only low-CO2, but also locally emission-free and almost silent operation. This makes it possible to achieve climate and environmental protection goals with existing vehicles and without the need for complex and expensive changes to infrastructure,” he added.
Ali Dogru, Head of Assets and Maintenance at DB Cargo, added, “Phasing out fossil diesel is one of the important pillars of DB’s efforts to become climate-neutral by 2040. It is very important for us that the existing engines in our shunting and mainline locomotives can be operated with HVO without restriction. This means that we can already make the last mile of the supply chain green and run freight trains for our customers in a completely CO2-neutral way.”
Since mid-August 2021, DB Cargo, in coordination with Rolls-Royce, first conducted engine bench tests and then operational trials, for example with DB Series 294 locomotives with an 8V 4000 R41 mtu engine running on HVO. After more than 1,800 operating hours, the results are promising.
“We were able to use HVO without any problems in our vehicles, without compromising performance and reliability,” said Dogru.
The evaluation of one of the engines after completion of the field test took place in September 2022. Rolls-Royce is now set to release the widely used mtu rail engines of the types 4000 R01 and R03 for synthetic diesel fuels of the EN15940 standard, including HVO. DB Cargo also uses HVO in other locomotives in its fleet.
Rolls-Royce announced in 2021, as part of its sustainability program Net Zero at Power Systems, that it will realign its product portfolio so that by 2030, new fuels and mtu technologies can reduce greenhouse gas emissions by 35% compared to 2019.