Spectral Characterization of Refined Oils and Their Binary Mixtures at Unconventional Temperatures

Abstract

The aim of this study is to address the problems of oil mixing during the sequential transportation of refined oil and the influence of temperature on the quality detection of refined oil. To better detect the quality of refined oil, UV-Visible transmission spectroscopic experiments of 92# gasoline, diesel oil, and their mixtures at different temperatures are performed. Then, the influence of temperature on the transmission spectrum is analyzed, and the transmittance–temperature compensation equations are obtained. Based on the double-thickness inversion model, the optical constants of the mixed refined oil at UV-Visible wavelengths are obtained, and the effect of temperature on the optical constants is analyzed. For a specified optical range, the transmittance of the mixed refined oil gradually increases with increasing temperature. The temperature has a certain effect on the optical constant of the refined oil; moreover, the relationships between the transmittance of the refined oil and the change in temperature are obtained at 364, 378, and 394 nm; these wavelengths are selected based on a combination of characteristic spectra calculated by a genetic algorithm. The obtained relationship can effectively remove the influence of temperature changes on the transmittance spectra of refined oil to improve the accuracy of detection.