Study of Stability Changes of Model Fuel Blends

Fuel during long-term storage, even at low temperatures, undergoes oxidation to various products, which are further converted into high molecular compounds precipitating from the liquid. The stability of the stored fuel depends on its chemical composition and storage conditions. Chemical conversions associated with the degradation of fuel are not well recognized, so it is difficult to predict the storage duration of such fuel and control the rate of ageing. Because of the variety of hydrocarbon composition of commercial fuels resulting from the diversity of crude oil and oil processing methods, surrogate fuels are used for simulating behaviour of commercial fuels in the various tests. In this paper, the type and dose of model components of fuel were chosen. To determine the degradation degree of model blends, few tests of accelerated ageing were selected. These methods were used to determine induction period, content of deposits and resistance to oxidation. Effect of inhibiting and catalyzing compounds on fuel oxidation was verified. An infrared spectroscopy analysis of the oxidized model blends was also performed. The results of this study showed slight changes of selected properties of the surrogate fuels. The most significant changes occurred for the model blends containing substances initiating radical autoxidation reactions and bio-components.