Synthetic fuels produced from renewable sources, so-called reFuels, are considered a potential game changer in the fight against climate change. Because reFuels not only promise up to 90 percent CO 2-Reduction compared to conventional fuels, they also allow the continued use of existing vehicle fleets with combustion engines - and the entire tank infrastructure from production to transport to sales. In a large-scale project with partners from industry, researchers at the Karlsruhe Institute of Technology (KIT) have now demonstrated in extensive application tests in fleets that reFuels can be used in almost all vehicles and can be produced in large quantities in the foreseeable future. They presented the results of the research project “reFuels – rethinking fuels” on Monday, September 19, in Karlsruhe.
“The use of climate-neutral fuels makes sense above all when battery-electric solutions are not yet a real alternative. In this respect, I am very pleased that the KIT has now been able to demonstrate impressively that reFuels are an equally climate-friendly and economical solution for certain areas of application," says Berthold Frieß, Ministerial Director in the Ministry of Transport Baden-Württemberg, on the occasion of the presentation of the results of "reFuels - new fuels think", the first reFuels project within the strategy dialogue automotive industry Baden-Württemberg (SDA). “The project also shows that the commitment of the state and other project partners to renewable fuels has paid off. Baden-Württemberg thus remains a pioneer in the mobility revolution.
"We will not be able to do without liquid fuels in the foreseeable future, for example in the area of heavy goods traffic, shipping and aviation, but also in the existing car fleet," says Professor Thomas Hirth, Vice President for Transfer and International Affairs at KIT. "In the 'reFuels – rethinking fuels' project, we have now shown that reFuels work in both old and new cars, as well as in commercial vehicles and locomotives," Hirth continues. "In short, reFuels are now fully suitable for everyday use!"
"We were able to produce tons of reFuels that meet the existing fuel standards for petrol and diesel fuels and have not shown any impairment in performance or wear in series use in a wide variety of engines," explains Dr. Olaf Toedter from the KIT Institute for Piston Engines. KIT researchers produced and tested gasoline and diesel. They have achieved a CO 2 reduction of 22 to 81 percent, depending on the mixing ratio between synthesized and fossil fuels, the raw materials used and the energy.
As a next step, the project partners want to set up an industrial production plant for reFuels on the site of the MiRO refinery in Karlsruhe: "In the future, we want to replace fossil raw materials with renewable energy sources," explains Dr. Andreas Krobjilowski, technical director of MiRO. “Many of the technologies and processes required for this are already available in Germany. MiRO has the know-how and experience to set up and operate such new and innovative systems.” However, there are currently not enough affordable quantities of green hydrogen available to switch to greenhouse gas-neutral production. The preliminary products for the reFuels fuels such as synthesized Fischer-Tropsch oil or methanol are therefore to be manufactured in countries that have more wind or solar energy than Germany, for example Chile or southern Spain. The actual reFuels such as petrol, diesel or kerosene could then be produced in domestic refineries such as MiRO. "However, for the urgently needed rapid market ramp-up, we need clarity and long-term security for counting renewable, electricity-based fuels against the greenhouse gas reduction quota," says Krobjilowski.
The scientists are also working on increasing the proportion of refuels in fuel mixtures within the existing fuel standards. "Right down to reFuels pure fuel," says Toedter. Tests already in progress have been promising. However, there is still a lack of a clear regulatory framework for this, because in Germany only up to 33 percent of refuels can be added.
In the project, researchers have been taking a holistic view of the production and use of renewable fuels since 2018. Such fuels can power existing combustion engines in the future – in airplanes, commercial and rail vehicles as well as in cars. Six institutes of the KIT work together with numerous partners from the energy, mineral oil, automotive and supplier industries under the umbrella of the Strategic Dialogue Automotive Industry of the State of Baden-Württemberg on the provision and introduction of reFuels. Two pilot and other technical systems of the KIT supplied regenerative fuels that were processed, characterized and tested in test engines and vehicles. In this way, synthesis processes for reFuels and their use could be optimized, for example, in addition to the CO 2-Reduction also to reduce raw emissions.