No abstract

In order to be able to continue using internal combustion engines in a sustainable manner, it must be ensured that these engines are operated exclusively with renewable, CO2‐neutral fuels (e‐fuels). An elegant way ito proof this is the use of a fluorescence sensor in the vehicle in combination with fuels that are labeled with a fluorescence marker. In this study we show that the benzophenonexazine compound Nile red proves to be a suitable fluorescence marker for fuel labeling, since the emission spectrum of fuels labeled with Nile red is in a suitable range of λem ∽ 600 nm ‐ 700 nm for sensory detection. Moreover, the fluorescence spectrum of this fluorescence marker proves to be stable to thermo‐oxidative aging over 192 h. Additionally, we discovered that, based on the exemplary aging of two monoalcohols, Nile red shows an antioxidant effect with respect to fuel aging of at least 33%.This article is protected by copyright. All rights reserved.

The complexity of biodiesel aging has shown that the mechanism needs further research. The rate of aging product formation and associated interactions can help improve fuel quality. Since biodiesel is a multicomponent system and constant changes occur in the chemical environment, which interactions yield which products must be shown in more detail. Particularly under observation was the correlation between peroxides and epoxides. In addition, it is critical that the influence and interactions of new drop-in fuel candidates be investigated. In this work, the kinetics of the formation of aging products of methyl oleate (C18:1) are studied. The aim was to reduce the complexity in order to be able to make more precise and detailed statements about the mechanism. Ketones, acids, peroxide, and epoxide values were recorded. A distinction is made between pure methyl oleate and mixtures with 3 wt% isopropylidene glycerine (solketal). After solketal decomposed in the blends, the aging process showed changes. The influence of solketal resulted in a higher number of acids and epoxides over time. It implied that peroxides are not necessarily the precursor of epoxides. In summary, correlation and solketal’s influence showed that a sequence of aging products could be detected.