Home – Home – Jornals – Advanced Search

The ability of heavy oil asphaltenes and oil residues to generate low and high molecular weight components during thermolysis at 290 °C is assessed. It was established that the conversion of asphaltenes exceeds 99 mass %, regardless of the degree of their transformation during the rectification of heavy oil. Oil asphaltenes generate the maximal amount of resins (21.4 mass %). while fuel oil and tar asphaltenes generate 9.4 and 7.3 mass %, respectively. It was shown that thermal transformations of asphaltenes during the rectification of heavy oil lead to the removal of large structural fragments from their molecules, thereby reducing the ability of asphaltenes to generate resinous substances at 290 °C. At the same time, the molecular structure of asphaltenes is compacted, which leads to an increase in their tendency to form coke-like products. The yield of coke-like products of the low-temperature thermolysis of asphaltenes from oil, fuel oil and tar is 42.1, 54.4 and 58.1 mass %, respectively. It is established that the thermal transformations of asphaltenes in the process of heavy oil rectification do not have any significant effect on their ability to generate gas and liquid hydrocarbons during thermal degradation. The results of the study should be taken into account when developing new technologies for the primary processing of heavy crude oils and upgrading the existing ones.

The rocks of Lower Cretaceous section in four exploration wells at the oil-producing fields of the Yamalo-Nenets Autonomous District were investigated. Dispersed organic matter was characterised by the composition of hydrocarbons using gas chromatography - mass spectrometry (GC-MC). Steranes, hopanes, n-alkanes and isoprenoid alkanes, naphthalenes, phenanthrenes, sesquiterpanes, dibenzothiophenes and dibenzofurans, retene, cadalene and simonellit were identified. Metalloporphyrins and perylene were determined by means of spectrophotometry. It was shown that the sediments studied were deposited under suboxidative conditions in the sedimentation basin with a significant contribution of both phytoplankton and terrestrial vegetation to the initial organic matter. Sedimentation proceeded near the coastline of the sea or in a coastal water body, which was periodically flooded by the sea. The thermal maturity of the organic matter corresponds to the major zone of oil formation.

The effect of the integrated action of low-frequency acoustic treatment, demulsifiers and the temperature factor on the stability and structural-mechanical properties of oil-water emulsions of paraffin low-resin oil from the Ignyalinskoye deposit is investigated. After low-frequency acoustic treatment of emulsions, water phase droplets are dispersed, and their number increases. Acoustic processing and introduction of demulsifier do not lead to the destruction of oil-water emulsions (10 mass %) stabilizing them due to an increase in the fragmentation of the dispersed phase. The integrated action is an effective method of the destruction of 50 mass % emulsions. After integrated processing, the size of the droplets of disperse phase in oil systems increases. Acoustic treatment of oil, oil-water emulsions (10 and 50 mass %) is accompanied by a quantitative increase in resin-asphaltene components. However, significant changes are observed only in the structural-group composition of asphaltenes.

Changes in the structural parameters of tar and asphaltene molecules of sediments obtained after oil dewaxing with liquefied petroleum gas at temperatures of 0, -5, -15 and -25 ° C were studied. It is shown that with a decrease in process temperature the amount of precipitate formed in the process increases from 10.9 to 13.4 mass %; deeper dewaxing, complete deasphalting and partial detarring also take place. It was established that a decrease in precipitation temperature from 0 to -25 ° C causes changes in the structural-group characteristics of asphaltene and resin molecules: molecular mass, the number of aromatic and naphthenic cycles, alkyl substituents and structural blocks in the molecule.

The process of elimination of hydrogen sulphide from methane in the plasma of barrier discharge in the presence of octane vapour is investigated. The use of octane vapour in the initial mixture with methane and hydrogen sulphide allows us to avoid the formation of deposit on the electrodes of the plasmachemical reactor and to achieve the high level of inhibition of the reactions leading to the formation of polymer-like compounds. The extent of hydrogen sulphide removal reaches 98 %, methane conversion does not exceed 10 %. Power consumption for the removal of hydrogen sulphide is 83 (kW · h)/kg. The major gaseous products of the treatment in the barrier discharge are hydrogen (30 %) and ethane (30 %). Among sulphur-containing products, mainly mono- and dialkyl sulphides were detected. A possible mechanism of the process is proposed. The ways to manage the plasmachemical process are substantiated.

The state of vegetation cover at the territory of Archinskoye, Shinginskoye, Kazanskoye, Yuzhno-Tabaganskoye and Zapadno-Ostaninskoye hydrocarbon deposits in the Tomsk Region was studied using satellite data from the MODIS spectroradiometer. The time series of the values of the Enhanced Vegetation Index (EVI) were calculated for the period from 2007 to 2019. Analysis of the dynamics of changes in the average EVI values allowed us to determine the minimal and maximal values of the index for the studied territories, and to identify a trend of an increase in its values, which indicates a good (non-depressed) state of vegetation and an improvement in the environmental situation of the studied territories of oil-producing complexes in the Tomsk Region.

The effect of the nature of the carbon template used in the synthesis of zeolites with a mesoporous pore system on their physicochemical properties is studied. It was revealed with the help of IR spectroscopy and X-ray phase analysis that the nature of the carbon material used in the synthesis of zeolites does not affect their crystallinity, which is 100 % for all zeolites. Investigation of the textural characteristics of the samples showed that the addition of carbon material to the reaction mixture during the synthesis of zeolite results in a decrease in the specific surface area and an increase in the volume of mesopores. The volume of micropores changes only slightly. The addition of carbon at the stage of zeolite synthesis leads to the formation of mesopores, the sizes of which are 3.5-20.0 nm in the case of the use of carbon black, and 3.3-8.6 nm in the case of nanoglobular carbon. The catalytic properties of Mo/ZSM-5 catalysts prepared on the basis of synthesised zeolites are studied, and the dependence of their activity and stability during the non-oxidative conversion of methane on the physicochemical properties of the zeolites used is shown. The formation of a mesoporous structure in the zeolite promotes a more uniform and dense distribution of Mo clusters with sizes not exceeding 1 nm in zeolite channels. It is shown that 4.0 % Mo/ZSM-5 catalysts based on zeolites with a mesoporous structure exhibit higher activity and stability in the non-oxidative conversion of methane to aromatic hydrocarbons than the catalysts based on zeolites with a microporous structure. The highest methane conversion is achieved over a 4.0 % Mo/ZSM-5 catalyst based on zeolite synthesised with carbon black.

The effect of the nature of the carbon template used in the synthesis of zeolites with a mesoporous pore system on their physicochemical properties is studied. It was revealed with the help of IR spectroscopy and X-ray phase analysis that the nature of the carbon material used in the synthesis of zeolites does not affect their crystallinity, which is 100 % for all zeolites. Investigation of the textural characteristics of the samples showed that the addition of carbon material to the reaction mixture during the synthesis of zeolite results in a decrease in the specific surface area and an increase in the volume of mesopores. The volume of micropores changes only slightly. The addition of carbon at the stage of zeolite synthesis leads to the formation of mesopores, the sizes of which are 3.5-20.0 nm in the case of the use of carbon black, and 3.3-8.6 nm in the case of nanoglobular carbon. The catalytic properties of Mo/ZSM-5 catalysts prepared on the basis of synthesised zeolites are studied, and the dependence of their activity and stability during the non-oxidative conversion of methane on the physicochemical properties of the zeolites used is shown. The formation of a mesoporous structure in the zeolite promotes a more uniform and dense distribution of Mo clusters with sizes not exceeding 1 nm in zeolite channels. It is shown that 4.0 % Mo/ZSM-5 catalysts based on zeolites with a mesoporous structure exhibit higher activity and stability in the non-oxidative conversion of methane to aromatic hydrocarbons than the catalysts based on zeolites with a microporous structure. The highest methane conversion is achieved over a 4.0 % Mo/ZSM-5 catalyst based on zeolite synthesised with carbon black.

The destruction of organic matter in oil-contaminated clay soil by native microflora was studied under laboratory conditions. Peat and the solution of a composition containing a surfactant and a nitrogenous substrate, as well as their combination with phytoremediation, were used as stimulating additives. After biodegradation, the residual oil was extracted and examined by means of IR spectroscopy, gas-liquid chromatography (GLC) and chromatography-mass spectrometry. According to the data of IR spectroscopy, peat and a solution of the composition promote the utilisation of paraffins, which is accompanied by an increase in the relative content of aromatic and carbonyl-containing structures. The isoprenoid coefficient K_i , which reflects the degree of hydrocarbon biodegradation, was calculated from GLC spectra as the ratio of iso- and n -alkanes. It increases with the introduction of stimulating substrates and soil loosening. The maximal biodegradation (biodestruction) coefficient is observed for the sample of oil-contaminated clay soil containing the surfactant composition, which contributes to oil emulsification and accelerates biodegradation. Acyclic ( n- and isoalkanes), alicyclic (cyclohexanes, drimanes, cheilanthanes, regular and rearranged steranes and hopanes), naphthenoaromatic (mono- and triaromatic steranes), and aromatic (mono-, bi-, tri-, tetra- and pentacyclic) hydrocarbons were detected in the soil organic compound (SOC) by means of chromatography-mass spectrometry. As a result of biodestruction stimulated by the introduction of peat and the nutrient substrate, the concentration of hydrocarbons decreased significantly: n-alkanes - by 74-82 %, aromatic compounds - by 97-99 %, cyclohexanes - by 78-92 %, oil steranes and hopanes - by 88-97 %. The introduction of the composition containing a nitrogenous substrate and a surfactant into the soil leads to a significant decrease in the content of C₁₂-C₃₄ alkanes to the level of background soil. The introduction of peat additive veils (shades) the results of alkane oxidation due to their presence in peat itself. The use of stimulating substrates leads to a decrease in the content of aromatic hydrocarbons during biodegradation: monocyclic by 82-89 %, bicyclic - by 55-81 %, tricyclic - by 74-89 %, tetracyclic - by 54-77 %.

Rubber-like elastic cryogels were formed from a two-component solution of polyvinyl alcohol in water after a freezing-thawing cycle, and their rheological properties are investigated. The interest in such environmentally friendly polymer cryostructures having viscoelastic properties is due to the fact that they are currently in high demand in the northern regions of the country. Cryogels are promising structural materials used for the development of new arctic technologies for oilfield engineering and for strengthening seasonally thawing soil in the permafrost zone, as well as for the construction and arrangement of hydraulic structures. As a result of the studies of the properties of cryostructuring agents, it was revealed that due to the mechanical action of external loads, elastic moduli of deformed cryogel samples decrease monotonously with time. Elastic moduli are traditionally used to quantitatively characterise the physical and mechanical properties of Hookean materials. The results of comparative experiments conducted by different researchers using the same cryogel samples are interpreted ambiguously due to the inconstancy of the elastic moduli of viscoelastic systems. In this work, the possibility and necessity to use cryogel relaxation time values as a quantitative criterion for describing the rheological properties of polyvinyl alcohol cryogels are experimentally substantiated. The values of the relaxation time of cryogels are proposed to be used instead of cryogel elasticity moduli to evaluate the viscoelastic properties of polymer systems in future design calculations.