 Aging of fatty acid methyl esters
Biogenic components from renewable resources like vegetable fats and fatty acids as well as their methyl esters are often added to heating oils and diesel fuels. The intended benefits include a stronger independence of fossil fuels and a reduction of the carbon dioxide emissions associated with combustion. These mixtures of biogenic compounds and fossil fuels, so called blends, often show a low stability towards oxidation. The uptake of oxygen by the unsaturated fatty acid methyl esters (FAME) leads to a higher polarity of the products with the consequence of formation of sediments. These can plug filters and nozzles in heating systems and cause huge economic losses.
There are some indications of synergistic effects between the fossil and the biogenic components. However, the dependence of the oxidation stability on the composition of the fuel mixture is not yet clarified. The longterm goal is to elucidate the formation of sediments and find indicator substances to predict the stability of blends.
Figure 1: IR-Spectrum of different aged and non-aged bio diesel blends
Involved group members: Stefanie Kerkering, Ruben Epping
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