THERMOCHEMICAL LUMINESCENCE AND CHEMICAL TRANSFORMATION MECHANISMS IN HEAVY CRUDE OIL RESIDUES

Summary: This study investigates the thermochemical luminescence (TCL) behavior of heavy residues derived from Karabakh, Absheron, and Naftalan crude oils to examine their chemical transformations and implications for quality. Crude oil is a complex mixture of hydrocarbons, dissolved gases, water, salts, and impurities, with its composition varying significantly. Advanced spectroscopic techniques, including UV, NMR, IR, and luminescence analysis, were utilized to explore the structural-group composition and physicochemical properties of these oils. TCL analysis revealed consistent characteristics among the heavy oil residues, marked by hybrid molecular structures and weakly bonded C–H linkages. The residues, after undergoing de-resinification and deasphalting, exhibited a notable uniformity, making them promising candidates for use as biologically active substances. Photoirradiation experiments demonstrated that the TCL maxima for heavy residues appear in lower-temperature spectral regions compared to many distillate fractions. The visible light emission was attributed to the decomposition of endoperoxides during the recombination of peroxide radicals. This observation opens the possibility of utilizing hydrocarbons as alternative light sources, including applications involving solar energy. These results have implications for improving refining processes, optimizing the transportation and storage of crude oil, and broadening the industrial applications of petroleum and its by-products.