Rolls-Royce is taking a significant step towards even more climate-friendly rail transport with the release of mtu rail engines for use with sustainable fuels, according to the company's release. With synthetic diesel fuels of the EN15940 standard, CO2 emissions can be reduced by up to 100 percent compared to fossil diesel.
Hydrotreated Vegetable Oil (HVO or renewable diesel), which is already commercially available today, reduces CO2 emissions by up to 90 percent. 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 in the near future. 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.
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.
The evaluation of one of the engines after completion of the field test is scheduled to take place in September 2022, after which Rolls-Royce will promptly 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.
Passengers can now travel to the German island of Sylt by land in an even more climate-friendly way than before. RDC Autozug Sylt and Rolls-Royce have recently started HVO field trials with a Vectron DE diesel-electric locomotive equipped with an mtu engine of type 4000 R04, which meets the strict EU Stage IIIB emission regulations for rail drives.
Following the successful completion of the tests with RDC, Rolls-Royce also intends to generally release the Series 4000 R04 engines for use with HVO and other EN15940 synthetic diesel fuels, as early as 2023. RDC is already using HVO in other services since July 2022.
Waste vegetable and animal fats and used vegetable oils can be used as base materials for HVO, which are converted into hydrocarbons by means of a catalytic reaction with the addition of hydrogen. Through this process, the properties of the fats and vegetable oils are adapted to diesel fuel and can supplement it as an admixture or replace it completely. The benefits of HVO are clean combustion with reductions in particulate emissions of up to 80 percent, nitrogen oxide emissions by an average of eight percent, and (depending on the manufacturing process and feedstock) CO2 emissions by up to 90 percent compared to fossil diesel. Because HVO fuel is produced from renewable raw materials, its combustion only generates about as much greenhouse gas as were absorbed by the plants during the growth of the biomass. Thanks to its production from residual and waste materials, there is no competition with food production.
Rolls-Royce announced in 2021, as part of its sustainability programme “Net Zero at Power Systems”, that it would realign its product portfolio so that by 2030, new fuels and mtu technologies can reduce greenhouse gas emissions by 35 per cent compared to 2019.