Development of a rapid aging method for middle distillate substitutes to reproduce the (long-term) storage stability behavior by means of parallel online measurement of several stability parameters.

Up to now, it has not been possible to estimate the further aging process of fuels on the basis of the initial analysis. Until now, this required long-term storage. Rapid aging methods provide a way to map this in a short time, but have been limited to general statements and have usually not been able to show any conclusions about the time dimension of the effects that occur. In this project, a model was developed that can be used to mathematically represent the correlation between a rapid aging process and long-term storage. The rapid aging process used accelerates the aging reactions with increased temperature and pressure, and various measurement parameters can be measured using an online sensor. Laboratory analyses as well as deposition and evaporation tests were performed on all samples. A method for temperature-dependent investigation of deposit formation was also developed and set up in this project. A qualitative correlation between aging condition and temperature was found with most of the deposits on the crucible surface. The data obtained from analyses and from sensor measurements were fitted using a function, and the fit data could then be used to analyze the correlations between rapid aging and long-term storage. A temporal relationship between the occurrence of the changes was found that could be used for prediction. The temperature dependence could be brought into the model, and the times of greatest change in various measured parameters for a sample can also be calculated using data from rapid aging. The errors of the method are still large, but an estimate can already be given.

The IGF project (21047 N) of the research association DGMK Deutsche Wissenschaftliche Gesellschaft für nachhaltige Energieträger, Mobilität und Kohlenstoffkreisläufe e.V., Große Elbstraße 131, 22767 Hamburg, Germany, was funded by the German Federal Ministry of Economics and Climate Protection via the AiF within the framework of the program for the promotion of joint industrial research (IGF) based on a resolution of the German Bundestag.