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A method of hydrothermal synthesis of pentasyl type zeolites (MFI or ZSM-5) with the silicate modulus of 40 is proposed, which consists in adding, along with hexamethylenediamine as a structure-forming agent (template), the second structure former - polyaniline, to alkaline alumosilicon gel. Polyaniline used in the work was also synthesised according to the authors’ method. It has been determined using IR spectroscopy and X-ray diffraction analysis that the synthesised zeolites belong to the pentasyl family, and their degree of crystallinity is close to 100 %. The acid characteristics of the obtained zeolite samples were studied by temperature-programmed desorption of ammonia, and a decrease in the strength and concentration of weak acidic centres in comparison with zeolite synthesised without the use of polyaniline was shown. On the contrary, the number of high-temperature acidic centres of zeolites obtained using polyaniline has somewhat increased. A correlation between the acidic properties of zeolites and the concentration of polyaniline added to the reaction mixture during synthesis has been established. The catalytic activity of the obtained zeolite catalysts was determined during the refining of the straight-run gasoline fraction of oil. An increase in the aromatising activity of the catalysts and the octane numbers of the resulting gasolines has been shown when using zeolites synthesised using two templates - hexamethylenediamine and polyaniline. The optimal temperature range for refining straight-run gasoline has been determined, which makes it possible to obtain high-octane gasoline, meeting the modern requirements for automotive gasoline in terms of hydrocarbon composition and octane number, on all the studied zeolite catalysts. The fractional composition of the gasoline produced (except for the final boiling point) corresponds to the summer grade of gasoline.

The potential for improving the low-temperature properties of summer diesel fuels using polymer additives is investigated. Polyalkyl methacrylate, sodium sulphonate, and atactic polypropylene with varying degrees of oxidation - low, medium, and high - were used as depressants. All polymers were used as toluene solutions with the polymer/toluene ratio ranging from 1 : 3 to 1 : 30 (by mass) and were introduced into the fuel at a concentration of 0.03-0.07 wt%. It has been found that the effectiveness of the compositions significantly depends on the degree of polymer dilution. The optimal polymer/toluene ratio has been determined to be within (1 : 6)-(1 : 10), providing pour point reduction to (-30)-(-33) °C, compared to the original fuel samples. It is demonstrated that the highest depressant activity is exhibited by the compositions based on highly oxidised atactic polypropylene. The maximum result was achieved by combining the products of plasma-chemical oxidation of benzene and toluene with polymers, which allowed reducing the pour point of fuel samples to -36.5 °C. The effectiveness of the additives also depended on the hydrocarbon composition of the fuel, showing better results in the samples with an increased content of low-molecular-weight n-alkanes C₁₆-C₁₇.

The results of laboratory studies on the effectiveness of GBK-F acid composition for enhancing oil recovery from terrigenous reservoirs are presented. Experiments on reservoir models with oil of various viscosities (Vostochno-Messoyakhskoye and Olenye fields) confirmed the ability of the composition to increase the displacement coefficient by 20-26 % at both low (22-23 °C) and high (90 °C) temperatures. It has been determined that the use of the composition significantly equalises filtration flows in heterogeneous systems. It has been shown experimentally that the composition effectively eliminates water blocking in low-permeability intervals, increasing the phase permeability for oil from 0.013 to 0.357 mm². It has been concluded that the mechanism of action of GBK-F is based on a complex chemical and rheological effect that improves the filtration characteristics of the reservoir. The obtained results allow us to recommend the use of GBK-F to intensity production and increase the coverage of heterogeneous terrigenous reservoirs.

Extensive analysis of the composition (material and fractional composition, sulphur distribution over components and fractions, content of thiophene derivatives, etc.) of liquid products formed in thermal cracking of high-sulphur oil shale from the Kashpir deposit has been carried out, the effect of temperature and process duration on these parameters has been demonstrated. It has been found that the yield of liquid products at cracking temperatures of 425 and 450 °C increases with an increase in the time of thermal treatment from 40 to 100 minutes, reaching 26.40 and 23.62 wt%, respectively, due to an increase in the kerogen destruction depth. A further increase in process temperature to 475 °C intensifies secondary reactions, leading to a decrease in the yield of liquid products and the distillate fractions within them. The distribution of sulphur over distillate fractions was studied, and the predominance of benzothiophene and dibenzothiophene homologues in the diesel fraction was established. It has been shown that at cracking temperatures of 425-450 °C, an increase in process duration causes sulphur redistribution from the diesel to gasoline fraction against the background of an increasing proportion of thiophene homologues, which indicates the predominance of dealkylation and fragmentation of complex heterocyclic structures. At 475 °C, dibenzothiophene and its homologues accumulate in the residual fraction (>360 °C). The obtained data will improve the understanding of the patterns of thermal transformation of sulphur-containing structural fragments in the organic matter of high-sulphur oil shales during cracking.

The article presents the results of long-term monitoring of ecosystem recovery following an accidental oil spill at the Krapivinskoye field (Tomsk Region) using remote sensing methods. The normalized difference vegetation index (NDVI), calculated from MODIS spectroradiometer data for the period 2020-2025, was used as an integral indicator of vegetation condition. A detailed analysis of the seasonal and interannual dynamics of the index was carried out, identifying seven phenological intervals within the growing season. It was found that the average annual NDVI value decreased by 2.41 % over the six-year observation period, indicating the long-term oil pollution impact. Despite some periods of improvement in the indicators, the ecosystem did not reach its original productivity level by 2025. The effectiveness of the satellite monitoring methodology for the operational assessment of vegetation condition and the efficiency of reclamation measures on disturbed lands is demonstrated.

The composition of biomolecules of herbaceous plants, some of which possess biological activity, has been studied and identified by chromatography - mass spectrometry in post-pyrogenic and background areas of the steppe zone of Khakassia. Insignificant differences were noted in the composition of acyclic compounds - n-alkanes, n-aldehydes, n-alkanols and long-chain n-alkanones. More significant changes are observed in the composition of steroids, though the pyrogenic effect on their composition in certain species of herbs varies and leads, along with different changes in the total content (from a decrease in the majority of plants to an increase in iris), to the redistribution of the proportion of individual representatives. Less stable to the action of fire were steroids with an unsaturated (double) bond in position 24 of the molecule, the content of which in the composition of all the studied herbs in post-pyrogenic areas is lower than in the background.

Results of studies on the activity and stability of Mo/ZSM-5 catalysts with a hierarchical pore system in the process of non-oxidative conversion of methane into aromatic hydrocarbons are presented. ZSM-5 zeolites were synthesised by hydrothermal synthesis with the addition of different amounts of polyaniline (3 %, 6 % and 12 %) as the second structure-forming agent (template), along with hexamethylenediamine (HMDA). The Mo/ZSM-5 catalysts were prepared from the zeolites and nano-sized Mo powder by solid-phase synthesis. According to IR spectroscopic data, all the synthesised zeolites belong to the ZSM-5 type and have 100 % crystallinity. It is shown that the addition of the second template (polyaniline) at synthesis stage improves the textural characteristics of the zeolite: increased specific surface area and mesopore volume, with an insignificant change of micropore volume, in comparison with ZSM-5 synthesised using only HMDA. With an increase in the amount of polyaniline added at the synthesis stage, the average pore size in the zeolite is observed to increase to 3.1 nm. The addition of polyaniline also causes changes in their acidic properties. The strength and concentration of strong acid centres of zeolite, related to Brønsted acid centres, are observed to decrease, which is probably due to changes in the distribution of Al atoms in zeolite structure and, as a consequence, to the redistribution of Brønsted and Lewis acidity. Non-oxidative methane conversion was carried out at a temperature of 750 °C and atmospheric pressure in a quartz reactor with a fixed catalyst bed. Catalytic tests have shown that the addition of polyaniline leads to the production of samples characterised by higher activity and selectivity for benzene formation. The best activity and stability are observed for Mo/ZSM-5 catalyst based on the zeolite synthesised with the addition of 6 % polyaniline, methane conversion was 11.5 %, and benzene yield was 6.7 %.

The distribution patterns of saturated and aromatic hydrocarbons in sod-podzolic soils one year after an accidental oil spill at an oil field in the Nefteyugansk district of the Khanty-Mansi Autonomous Okrug are considered. Soil samples were collected from the depth of 0-10, 10-30, and 30-50 cm. The composition and distribution of hydrocarbons were determined using gas chromatography-mass spectrometry. The total pollutant content was found to be unevenly distributed: the highest concentrations are confined to the surface layer, while the minimum values are characteristic of the middle interval (10-30 cm). In all horizons, n-alkanes account for the majority of the contamination, while isoprenoid alkanes and polycyclic aromatic compounds are present in smaller quantities. It has been shown that in the intermediate (10-30 cm) layer, the ratio of individual aromatic compounds changes: in particular, the contribution of methyl-substituted naphthalene homologues decreases and the relative content of phenanthrene homologues increases. Predominance of high-molecular-weight odd n-alkanes, characteristic of biogenic soil organic matter, was also recorded in this layer. Individual n-alkanes include homologues from C₁₃ to C₃₅. It has been found that the average number of carbon atoms in homologous series for compounds with long alkyl chains increases for most groups of compounds when moving from oil to soil.

A comparative study of the composition of the supramolecular and molecular structure of resin-asphaltene components isolated from the light oil of the Krapivinskoye field and heavy oil of the Usinsk field and the residues after their atmospheric distillation has been carried out. Using a set of methods - scanning and transmission electron microscopy, X-ray diffraction and structural group analysis - the features of the surface morphology of asphaltenes and their nano- and microstructure, as well as the features of the structural organisation of oil resins before and after their primary processing were revealed. It has been established that asphaltenes and resins of heavy oil undergo more pronounced structural transformations. The results obtained expand the understanding of the behaviour of high-molecular oil components under thermal action and can be used to optimise technologies for processing residual fractions and predict their operational properties.

Results of the synthesis of binary systems and ternary system of deep eutectic solvents (DESs) based on glycerol, choline chloride and urea are presented, along with the studies of their physicochemical and rheological properties, including the properties of their aqueous solutions. Based on the conducted studies involving the addition of a complex surfactant to DES, a new neutral-alkaline oil-displacing composition was developed. The results of laboratory tests aimed at studying the effect of the developed composition on the filtration characteristics of the heterogeneous formation of the Usinskoye field, as well as on the composition and properties of oil itself, are presented. The neutral-alkaline oil-displacing composition is applicable to various geological and physical conditions, in particular in the northern and Arctic regions. The effectiveness of the composition was evaluated under natural, steam-thermal, and steam-cyclic development conditions. Its use was found to smooth out filtration flows, increase reservoir sweep efficiency, restore permeability, and, as a consequence, increase oil displacement efficiency significantly over a wide temperature range. Analysis of the composition and properties of heavy, high-viscosity oil using IR spectroscopy and chromatography - mass spectrometry has shown that the developed composition alters oil characteristics by breaking the bridges linking saturated hydrocarbons with the esters/acids of resinous components. This leads to an increase in the proportion of oil fractions, with a simultaneous reduction of resin content, resulting in lower viscosity and improved oil quality.