Slowing down natural aging processes

Interior view of a heating oil pump: After about 400 hours of operation with biofuel oil (heating oil with 10 % FAME), deposits are clearly visible. Photo: OWI

6 July 2018 – Diesel fuel and heating oil, which chemically belong to the middle distillate group, are subject to natural ageing during storage. The addition of alternative and biogenic liquid fuels to mineral oil-based middle distillates can accelerate the aging processes. For example, fatty acid methyl esters from regenerative raw materials promote the increased formation of sediments and acids as well as oxidation. The causes of sedimentation have not yet been fully explained. If fuels produced from different fossil and alternative raw material sources are mixed, effects occur which have not yet been sufficiently investigated.

In addition, interactions between fuels and new materials as well as design changes to components in heaters and engines can create additional challenges, such as blocking nozzles, pumps, filters, injectors and preheaters.

The OWI Oel-Waerme-Institut gGmbH and the ITMC Institute of Technical and Macromolecular Chemistry at RWTH Aachen University are therefore investigating the mechanisms of sediment formation using biofuel oils in accordance with DIN SPEC 51603-6. The research project aims to uncover the conditions under which such operation-disturbing sediments are formed and which groups of substances are involved in their formation. This knowledge can be used to develop new methods for the production and analysis of heating oils and to design new additive products. The results of the investigations can be transferred to diesel fuels, as very similar challenges occur on the fuel side in the respective applications. Finally the results are particularly relevant for the mineral oil, biofuel, raw material and additive industries up to companies that use middle distillates in their applications (automotive industry, component manufacturers, analysis laboratories).