To answer this question, OWI Science for Fuels gGmbH and the Max Planck Institute for Coal Research (MPI) want to conduct a preventative study to find out whether undesirable interactions can occur between aged conventional and new paraffinic heating oils and, if so, how they could be prevented.
Greenhouse gas-reduced paraffinic heating oils can be produced both from natural oils and fats by hydrogenation and synthetically from – for example, electricity-based – carbon-hydrogen mixtures via Fischer-Tropsch synthesis and are already available on the market as HVO (Hydrogenated Vegetable Oil) and GTL (Gas-to-Liquid). The properties of paraffinic fuels are so similar to those of heating oils that they can be used in existing oil-fired heating systems with minor technical modifications. The long-term storage stability of paraffinic heating oil is even better than that of mineral oil-based heating oil.
Heating oil is stored for months and sometimes years in heating oil tanks and is subject to natural aging over time. In the process, its chemical composition changes and aging products are formed. When a paraffinic fuel oil is refueled on top of a residual fuel oil containing mineral oil, the result is a mixture from which, theoretically, the aging products could precipitate more easily in the form of sediments. During heating operation, for example, the fuel pump could then suck in the aging products along with the fuel, which could then enter the prefilter of the heating system and clog it. The interactions and underlying processes in the long-term behavior and possible countermeasures, such as suitable additivation of the fuel, are the subject of the investigation by OWI and MPI. The two research institutes intend to proceed with fuel analysis and application technology procedures and, if necessary, to develop new or further methods.