Cold Weather and Turbidity Behavior of Diesel Fuels Containing Sustainable, Paraffinic Components

Since May 2024, paraffinic diesel fuel has been available at public gas stations in Germany in accordance with the 10th BImSchV. Paraffinic diesel fuels—in particular, hydrotreated vegetable oils (HVO) derived from sustainable biogenic feedstocks—can significantly reduce greenhouse gas emissions compared to fossil diesel. As such, they make an important contribution to climate protection in both the existing vehicle fleet and in new internal combustion engines. The motivation for this research project stems from a series of pressing scientific and technical challenges faced in particular by small and medium-sized enterprises in the context of the energy transition and the shift away from fossil fuels. Although HVO is already available as a „drop-in“ fuel, there remains a need for in-depth fundamental knowledge to fully exploit its potential. The project aims to close key gaps in knowledge regarding the low-temperature properties and emulsion formation of paraffinic diesel fuels.

To this end, experimental studies are being conducted using a broad range of fuels. With regard to the low-temperature properties of paraffin-rich diesel fuels, the CFBT method will be systematically tested, and its potential for ensuring the operability of vehicles as well as technical equipment such as emergency power systems, generators, or construction machinery will be evaluated. On an experimental basis, the factors influencing fuel cloudiness and the stability of water-in-fuel emulsions are also being investigated. It is assumed that the composition of paraffinic fuels plays a decisive role in their tendency to form emulsions. By using surrogate blends, the chemical composition can be specifically varied to identify key influencing factors. In addition, the influence of lubricity-enhancing additives is analyzed.

This project is funded by the Federal Ministry for Economic Affairs and Energy pursuant to a resolution of the German Bundestag (IGF Project 01IF25116N).

The grant award notice from the BMWE has been received. The project will begin on June 1, 2026.