THE EFFECT OF ADDITIVES CONTAINING POLYCYCLIC ARENAS ON THE FORMATION OF THE PROPERTIES OF BITUMEN BINDER IN THE PROCESS OF THEIR JOINT OXIDATION WITH OIL TAR

The results of the study of the effect of polycyclic aromatic hydrocarbons (PAHs) on the efficiency of the process of oxidation of oil tar into bitumen are presented. By-products of oil refining were used as additives to tar: the residue of heavy pyrolysis resin (OTSP) and 2 samples of extracts (MAE-1; MAE-2) isolated from extracts of selective purification of oil distillate VD-3 using a polar solvent N-methylpyrrolidone containing 10 wt.% ethylene glycol. One of the extracts, MAE-2, was obtained from an oil extract pretreated with microwave radiation. Additives were injected into the tar at 70 ℃ in an amount of 10 wt.%. The hydrocarbon system was oxidized with air oxygen for 6 hours at a temperature of 220 ℃. Based on the analysis of the properties and group, structural and group compositions of oxidized bitumen binders, it was found that the content of benzene resins in the binder increases (~ 2.5 times) and asphaltenes (by 3 wt.%) during the oxidation of the mixture of MAE-1 + OTSP. When the mixture of MAE-2 + OTSP is oxidized, the content of benzene resins and asphaltenes in the binder decreases. The observed changes in the compositions of the oxidation products of mixtures of MAE + OTSP are preserved during the oxidation of tar + systems (MAE + OTSP). At the same time , the conditional content of aromatic structures according to the data of the IR spectrometric analysis in the oil component of the oxidized tar + system (MAE-2+OTSP), as well as poly-substituted polycyclic aromatic structures, is almost 2 times higher than for the oil component of the oxidized tar + system (MAE-1+OTSP). As a result, the oxidation of tar mixtures with additives containing polycyclic arenas improves the quality of the target product by increasing the content of asphaltenes and aromatic structures in the aromatic oil component.