The method, based on storage simulator and IR – VIS spectroscopy, for predicting the allowable time of storage of biocomponents for CI engines

The paper presents the results of investigations concerning a new method used for predicting the allowable time of storage of biocomponents – FAME. The method was based on laboratory research carried out with the use of a storage tank simulator. The aging process was carried out in the conditions increasing the reaction rate – at high temperature. There are several methods/procedures used for predicting the allowable time of storage of fuels and biocomponents – FAME, but all of them are based on tests at the temperature so high that the mechanism of aging process is different than the one observed in storage tanks. It was assumed that the aging process could be divided into two stages: at the first stage, the aging precursors are created and at the second stage, precursors are converted into the fuel aging products. These products lead to changes in fuel properties. The kinetics of precursor creation determines the rate of all reactions, which lead to the final aging products. It was found that the rate of reaction at the first stage of fuel aging can be effectively increased by an increase in temperature and even relatively high temperature does not change the mechanism of the creation of aging precursors. The method that has been worked out makes it possible to control the mechanism of aging process during quick laboratory tests. The products of aging processes were detected with the use of the IR-VIS spectrometry. The allowable time of storage was determined for several FAME samples on the basis of quick laboratory tests. The results of laboratory quick tests were verified by comparing them with the results of the aging process of FAME in storage tanks. On the basis of the test results, the algorithm of allowable time of FAME storage calculation was worked out.