In order to evaluate the possibility of using different catalysts prepared for the hydrogenation process of primary coal tar, the method of differential thermal analysis was used, which allows to determine the kinetic parameters of thermal destruction, such as the rate constant, activation energy, and pre -exponential multiplier. The effect of catalysts on characteristics of mass loss during heating of "Shubarkol Komir" JSC primary coal tar at a constant speed (20 K/min) in a nitrogen medium has been considered. Microsphere, NiO/microsphere, CoO/microsphere, chrysotile and NiCo/chrysotile have been taken as catalytic additives. In the presence of the catalysts, the rate of thermal destruction of primary coal tar increases in the following order: CoO/microsphere < NiO/microsphere < NiCo/chrysotile. While microsphere catalysts extend the range of thermal destruction, chrysotile catalysts lead to the rapid completion of the destruction process. This fact is characterized by the formation of bonds between catalytic additives and primary coal tar. It is important to determine such parameters that affect on the activation energy and macrokinetics of the thermal decomposition process for prediction of catalyst activity during hydrogenation of heavy hydrocarbon raw materials.

Production of artificial humic acid (AHA) from waste biomass will contribute to environmental protection and agricultural productivity. However, there is still a lack of a faster, more efficient and eco-friendly way for sustainable production. In this study, potassium humate was prepared from agricultural waste tobacco straw by thermal catalysis using environmentally friendly Fe2O3 as a catalyst. The yield of potassium humate was successfully increased to 68.77 %. In the present study, using characterization methods such as TG-DTG and UV, it was found that the potassium humate prepared from tobacco straw had lower aromaticity, smaller molecular weight, as well as better solubility and better quality. In addition, the effect of potassium humate fertilizer on wheat biomass was also investigated in this experiment by wheat hydroponics. The results showed that the germination rate of wheat increased by 17 % and the fresh and dry weights increased by 6.94 % and 19.31 %, respectively, with the addition of potassium humate prepared with iron catalyst. This study provides a green and simple technology for the resourceful utilization of tobacco straw to produce high value-added potassium humate, and enriches the source of raw materials for potassium humate, expanding its application in the field of crop growth.

The temperature dependence of dynamic viscosity was calculated on the basis of a new cluster-association equation, which was derived within the framework of the concept of chaotic particles. It was shown that the degree of cluster association naturally decreases with an increase in temperature, on average corresponding to the arrangement of three to four cluster particles in the association. For the first time, the values of the activation energy per monomer were obtained when assigning the activation energy to the average number of clusters.

The paper presents the results of an investigation into the kinetics of catalytic hydrogenation of vacuum residue at temperatures of 380, 400 and 420 °C and different durations, ranging from 30 to 70 min, using a nanocatalyst containing the active metals nickel and titanium supported on chrysotile. It was found that the yield of oils from 30 to 50 wt.% and tars from 12 to 18 wt.% increased with increasing temperatures and reaction times. A slight increase in the proportion of solids in the range of 2.0 to 6.0 wt.% is explained by the activity of the nanocatalyst used. In the study of the kinetics of vacuum residue hydrogenation, using the nanocatalyst developed by the authors, we were able to achieve a low yield of solids with a short contact time as well as a high yield of low-molecular-weight compounds such as oils and tars. To determine the kinetic parameters (rate constants and activation energies), Simpson’s integral method and a random search engine optimization method were used. High values of rate constants are characteristic of reactions in the formation of oils k1, tars k2 and asphaltenes k3 in the temperature range of 380–420 °C. The high values of the rate constants k1, k2 and k3 in the catalytic hydrogenation of the vacuum residue indicate the high reaction rate and activity of the nanocatalyst used. With an increase in temperature from 380 to 420 °C, the rate constant of the formation of gas products from vacuum residue and the conversion of asphaltenes into oils significantly increase, which indicates the accumulation of low-molecular-weight compounds in oils. The activation energy for reactions leading to the formation of oils, tars, asphaltenes, gas and solid products was 75.7, 124.8, 40.7, 205.4 and 57.2 kJ/mol, respectively. These data indicate that the processes of vacuum residue hydrogenation with the formation of oils and asphaltenes require the lowest energy inputs. Reducing the process temperature to increase the selectivity of the vacuum residue hydrogenation process when using the prepared nanocatalyst is recommended. The formation of oils at the initial stage plays a key role in the technology of the heavy hydrocarbon feedstock (HHF) hydrogenation process. Perhaps the resulting oils can serve as an additional solvent for high-molecular-weight products such as asphaltenes, as evidenced by the low activation energy of the process.

The optimal conditions for demetallization of the heavy fraction of coal tar from Shubarkol Komir JSC were determined by means of full factorial experiment. Optimal conditions for demetallization of the aforementioned fraction were found to be a proportion of "Coal shale" catalytic additive to the heavy fraction of coal tar with boiling point above 300 degrees & Scy; equal to 0.04, process temperature in the range of 420-430 degrees & Scy;, duration from 20 to 30 minutes and initial pressure between 3 and 5 MPa. Experiments conducted under these conditions demonstrated the demetallization rates of 87-89 %. Conversion of the heavy fraction of coal tar in hydrogen medium at pressure of 4.0 MPa and temperature of 420 degrees C was examined, with and without the use of the "Coal Shale" catalytic additive. The findings demonstrate that the incorporation of the "Coal Shale" catalytic additive is associated with a notable enhancement in the production of liquid hydrogenate, reaching up to 57 %. Atomic emission spectral analysis was used to investigate the content of rare and dispersed elements including Ge, Ga, Y, Yb, Zr, Nb the ash of the heavy fraction of coal tar and the "Coal shale" catalytic additive, as well as in the solid product of demetallization of the heavy fraction of coal tar using the catalytic additive. The results showed that the use of "Coal shale" as the catalytic additive leads to an increase in the content of Ga, Yb, Y elements by 3-3.8 times, and Zr - by 7.5 times compared to the initial heavy fraction of coal tar in the absence of the catalytic additive.

The laws of thermal degradation of the mixture of the heavy fraction of low-temperature coal tar and coal shale were investigated using dynamic thermogravimetry. The kinetic characteristics of the process were determined using various methods, including the Ozawa–Flynn-Wall, Friedman, non-parametric kinetics and Šesták–Berggren methods. It is shown that coal shale initiated changes in the kinetic parameters and decomposition rate of the heavy fraction of coal tar. It was found that a 13% content of coal shale in the mixture led to the maximum rate of weight loss of the heavy fraction of coal tar. A hydrodemetallization kinetic model of the mixture of the heavy fraction of low-temperature coal tar and coal shale is proposed. The kinetic parameters of the hydrodemetallization process were determined; in addition, the rate constants at various temperatures were estimated. The study shows that the distribution of trace elements in the hydrogenate from the initial mixture and in the hydrogenate from the solid residue was characterized by relatively low values of reaction rate constants. The maximum microelement distribution rate was achieved in the hydrogenate solid residue. Energy indicators of activation processes indicated that hydrodemetallization at low temperatures is advantageous from an energy point of view.

The development of highly efficient water oxidation catalysts is a bottleneck in achieving artificial photosynthesis, as water oxidation is a complex process involving multiple electron and proton transfers. To further improve the photocatalytic water oxidation performance of MIL-53(Fe), a series of Ag/AgCl@MIL-53(Fe) samples with different Fe:Ag ratios were synthesized by hydrothermal methods and used in the photocatalytic water oxidation reactions. XRD characterization showed the successful preparation of Ag/AgCl@MIL-53(Fe) heterostructure catalysts. The reaction results showed that sample AAM-2 (Fe:Ag=5:1) had the best photocatalytic water oxidation performance, with the highest TOF value of 0.14 mmol/(gs) and quantum efficiency of 39.0 % under the conditions of catalyst mass of 1 mg and pH=9.0 for boric acid-borax buffer solution. Measurements of photocurrent indicated that the AAM-2 samples doped with Ag/AgCl had higher photocurrent densities, thus improving the photocatalytic performance. This provides new insights for constructing highly efficient porous MOFs catalysts.

For the first time, thermal decomposition of vacuum residue and a mixture of vacuum residue with binary nanocatalysts based on leached and non-leached chrysotile with applied active metals was studied using the thermogravimetry method. It is shown that the thermokinetic parameters of decomposition of vacuum residue and its mixture with binary nanocatalyst are different. The phase composition of the binary nanocatalyst was established through X-ray phase analysis (XRD): (Mg3Si2O5 (OH), NiO and Ti (SO4)2). The quantitative content of elements on the chrysotile surface was determined using X-ray fluorescence analysis: (Ni (4.88%), Ti (7.29%), Si (24.93%), Mg (7.83%), Fe (0.69%) and S (3.89%)). Using atomic emission spectral analysis, the gross quantitative content of supported metals on chrysotile was determined: Ni (4.85%) and Ti (4.86%). A transmission electron microscope showed the presence of finely dispersed particles adsorbed on the surface of and possibly inside chrysotile nanotubes with sizes ranging from 5 to 70 nm. The acidity of the nanocatalyst obtained from the leached active-metal-supported chrysotile was 267 μmol/g and the specific surface area of the nanocatalyst was 54 m2/g. The Ozawa–Flynn–Wall (OFW) method was used to calculate the kinetic parameters of the thermal degradation of vacuum residue and the mixture of vacuum residue with nanocatalysts. Using the isoconversion method, the average values of activation energies and the pre-exponential factor were calculated: 147.55 kJ/mol and 3.37·1016 min−1 for the initial vacuum residue; 118.69 kJ/mol and 1.54·1018 min−1 for the mixture of vacuum residue with nanocatalyst obtained from non-leached chrysotile with applied metals; 82.83 kJ/mol and 2.15·1019 min−1 for the mixture of vacuum residue with nanocatalyst obtained from leached chrysotile with applied metals. The kinetic parameters obtained can be used in modeling and designing the processes of thermal degradation and hydroforming of heavy hydrocarbon raw materials.

The article is devoted to the experimental determination of thermokinetic parameters of oil sludge thermal degradation using the model-free Ozawa-Flynn-Wall method in the presence of a nanocatalyst (nickel, cobalt and iron-supported microsilicate) by calculating Arrhenius kinetic parameters (activation energy and pre-exponential factor). The phase composition of the reflex microsilicate was established – 4.12; 2.51 Å – SiO2, nickel-supported microsilicate reflexes: 2.09; 1.48 Å – NiO, reflexes: 4.25 Å – SiO2 and acid numbers of microsilicate – 64 μmol/g of prepared nanocatalysts. Using the method of Brunauer, Emmett and Teller, the specific surface area of the microsilicate was established – 18.3 ± 0.3 m2/g, the microsilicate with nickel applied – 20.9 ± 0.2 m2/g and the adsorption isotherm of the prepared nanocatalysts (microsilicate with nickel, cobalt and iron). Thermokinetic parameters of thermal decomposition of oil sludge without a catalyst and with a catalyst at an increment of 0.9 are 99.0 and 93.3 kJ/mol nickel-supported microsilicate, 51.9 kJ/mol cobalt-supported microsilicate, 111.3 kJ/mol iron-supported microsilicate and non-metal-supported microsilicate 173.7 kJ/mol, respectively. The study of the kinetic parameters of pyrolysis of oil sludge using various catalysts makes it possible to assess their influence on the process of decomposition of organic components. The results of the experiments showed that the use of catalysts significantly affects the destruction of oil sludge. Dynamic thermal analysis at different heating rates studied the dynamics of oil sludge decomposition. The study of the effect of catalysts on the kinetic parameters of oil sludge pyrolysis is an important step in the development of new methods for the disposal of petroleum products and the reduction of their negative impact on the environment. The obtained experimental data on thermal degradation kinetics of oil sludge will find application in designing a reactor for the process of destructive hydrogenation of heavy hydrocarbon raw materials.

The optimal conditions of catalytic hydrogenation of oil sludge (Atasu-Alashankou) and the change in the kinematic viscosity of the fraction to 350℃ from the studied factors using the method of probabilisticdeterministic planning were experimentally determined. During the hydrogenation process of oil sludge, the maximum total yield of light fractions reached 62.1 %, and the kinematic viscosity decreased from 2.2 to 1.2 mm2/s. It was established the initial hydrogen pressure and the amount of added nanocatalyst microsilicate with cobalt (catalyst 1) have the greatest influence on the yield of the middle fraction from oil sludge under experimental conditions. It was shown that catalyst 1 increases the yield of diesel fraction components during the hydrogenation process of oil sludge. For the first time, we established the individual and group chemical composition of the fraction up to 350℃ before and after processing. The use of nanocatalyst 1 in amounts of 1.2–1.5 % led to an increase in the yield of the fraction up to 350℃ and diesel fraction components. This is due to the yield of paraffinic hydrocarbons increasing from 57.6 (initial fraction) to 80.7 %, as well as a decrease in aromatic hydrocarbons from 14.1 to 12.9 % and polycyclic aromatic hydrocarbons from 9.56 to 4.3 %.

Научная новизна работы состоит в отображении температурной зависимости вязкости кластерно-ассоциатной вероятностной математической моделью, иерархическая структура которой адекватна физической природе агрегации частиц без учета их конкретного строения, но с учетом изменения степени их ассоциации с повышением температуры. Расчет данных проводился на основе нового кластерно-ассоциатного уравнения, которое было выведено в рамках концепции хаотизированных частиц. Приведены расчетные данные в температурном диапазоне от температуры начало кипения и конец кипеня. Показано, что степень ассоциации кластеров при повышении температуры закономерно понижается, равная в среднем трех-четырех-частичной компоновке кластеров в ассоциате. Проведено сопоставление кластерно-ассоциатной модели с уравнением Френкеля в логарифмических координатах.

Herein, we disclosed a method of preparing a nanocatalyst containing nickel-cobalt by impregnation in a hydrochloric acid medium. Optimal conditions were established for all stages of nanocatalyst preparation using the method of probabilistic–deterministic experiment planning: hydrochloric acid concentration—1 mol/L, ratio of HCl concentration to nickel concentration—20, ratio of HCl concentration to cobalt concentration—20. The method of planning the experiment of preparing a nanocatalyst allows varying all the factors simultaneously and obtaining quantitative estimates of the main effects and effects of interaction, as well as establishing the dominant factors affecting the activity and selectivity of the nanocatalyst during the hydrogenation of benzothiophene. The multifactorial equation was obtained, which allowed us to calculate the optimal manufacturing parameters of the nanocatalyst, providing high activity and selectivity during the hydrogenation of benzothiophene. In the proposed nanocatalyst, a readily available natural chrysotile–asbestos with a nanotube diameter of 60–75 nm was used as a carrier for the benzothiophene hydrogenation process.

The catalytic properties of ultrafine nickel powder with a specific surface area of 11.7 m2/g and an average crystallite size of 34 nm, which was obtained by combining dc electrolysis and high-voltage discharge, were determined. The resulting nickel powder was used as a nanoheterogeneous catalyst in the hydrogenation of anthracene and phenanthrene. The degrees of conversion obtained with the use of the ultrafine nickel powder were compared with the values obtained using a commercial iron–chromium catalyst STK-1 (83.0% Fe2O3, 7.5% Cr2O3, and 2.0% CuO) under the same conditions. It was found that the highest conversion of anthracene in the process of hydrogenation for 60 min at a temperature of 450°C and a hydrogen pressure of 3 MPa was 86.24% in the presence of the nickel powder obtained or 91.35% with the use of STK-1. In the hydrogenation of phenanthrene for 60 min at a temperature of 400°C and a pressure of 5 MPa, the conversion was 32.28 or 25.9% with the use of the nickel powder or STK-1, respectively.

Влияние наноразмерного порошка железа на процесс термической деструкции дистиллята каменноугольной смолы было определено методом термогравиметрического анализа. Дистиллят каменноугольной смолы был получен простой перегонкой до 350°C первичной каменноугольной смолы Шубаркульского месторождения. Наноразмерный порошок был получен электрохимическим восстановлением железа из сульфатных электролитов при одновременном воздействии высоковольтных электрических разрядов на катодную зону. Методом сканирующей электронной микроскопии было установлено, что порошок железа состоит из наноразмерных частиц (30-124 нм), образующих агрегаты. С помощью рентгенофазового анализа было установлено, что полученный порошок железа состоит в основном из фаз α-Fe и FeO(OH). Определение среднего размера кристаллитов было произведено с помощью уравнения Шеррера и в результате расчетов средний размер кристаллитов составил 31,7 нм. Полученный порошок железа добавляли к дистилляту каменноугольной смолы в количестве 1% от массы дистиллята и затем эту смесь подвергали термическому разложению при скоростях нагрева 5, 10 и 20°C/мин в инертной атмосфере. Обработка полученных данных проведена с использованием модельного метода Коутса-Редферна. Значения энергии активации были рассчитаны с помощью линейной аппроксимации, построенной в результате обработки термоаналитических данных. Установлено, что при добавлении наноразмерного порошка железа в количестве 1% к дистилляту каменноугольной смолы происходит снижение энергии активации со 153,98 кДж/моль до 84,48 кДж/моль.

The thermokinetic parameters of the thermal decomposition of primary coal tar (PCT) from AO Shubarkol Komir in the Republic of Kazakhstan in the presence of a microsilicate nanocatalyst were experimentally determined. The salts of Group VIII metals (iron, cobalt, and nickel) were preliminarily supported onto the surface of the nanocatalyst. The method of thermogravimetry in an inert atmosphere of nitrogen was applied. The thermokinetic parameters of the decomposition of PCT (activation energy, preexponential factor, and rate constants) found in the absence and presence of the nanocatalyst were calculated using thermogravimetric analysis methods. The experimental results of the kinetics of PCT decomposition can be used to develop a database for the mathematical modeling of the processing of this type of raw materials.

Optimal conditions for producing ultrafine iron powder by combining the processes of electrolysis and high-voltage discharge have been determined. It has been established that the maximum current efficiency q = 97.88% is achieved at a current density of D = 10000 A/m 2 , an iron sulfate concentration of C (FeSO 4 ⋅7H 2 О) = 50 g/L, a process duration of τ = 60 min, an ammonium sulfate concentration of C ((NH 4 ) 2 SO 4 ) = 40 g/L, and a voltage of U = 8000 V. Using electron microscopy, it has been found that the obtained iron powder contains nanosized particles having the BET specific surface area of 31.5 ± 0.3 m 2 /g as determined using low-temperature nitrogen adsorption. Analysis by Mössbauer spectroscopy showed the presence of magnetically ordered phases α-Fe and γ-Fe 2 O 3 , a phase close to α-FeOOH hydroxide (goethite), and possibly a mixture of β-FeOOH (acoghanite) and γ-FeOOH (lepidocrocite). It has been found that the conversion of phenanthrene during hydrogenation for 60 min in the presence of this iron powder is higher than in the presence of the industrial iron–chromium catalyst STK-1 and reaches 32.99%.

Impact of the nanosized iron powder on the process of thermal degradation of coal tar distillate was determined by the thermogravimetric analysis. Coal tar distillate was obtained by simple distillation up to 350°C of primary coal tar from the Shubarkol deposit. Iron powder was obtained by electrochemical reduction of iron from sulfate electrolytes at simultaneous impact of high-voltage electric discharge on cathodic zone. Scanning electron microscopy showed that iron powder consists of nanosized particles (30-124 nm) forming aggregates. X-ray diffraction analysis revealed the presence of α-Fe and FeO(OH) phases. The average crystallite size determination was made using Scherrer equation and amounted to 31.7 nm. Obtained iron powder was added to the coal tar distillate in amount of 1% of distillate weight and this mixture was subjected to thermal degradation at heating rate 5°C/min in an inert atmosphere. Processing of the data obtained was carried out using the model-fitting Coats-Redfern method. The values of activation energy were calculated from the linear approximation constructed as a result of processing thermoanalytical data. It was found that the addition of iron powder in amount of 1% to the coal tar distillate reduces the activation energy from 153.98 kJ/mol to 84.48 kJ/mol.

Regularities of influence of nickel nanopowder on the thermal degradation of coal tar distillate were deter-mined using model-free Kissinger, Flynn-Wall-Ozawa and model-fitting Coats-Redfern methods. Coal tar distillate with a boiling point of <350 °C was obtained by simple distillation of primary coal tar from the Shubarkol deposit. Nickel nanopowder was used as a catalyst and was added to coal tar distillate in a quantity of 1 % of the mass of the distillate and then the process of thermal degradation of coal tar distillate was con-ducted at heating rates 5, 10 and 20 °C/min in an inert gas medium. Nickel powder was obtained by high-voltage discharge impact on the dc electrolysis. X-ray diffraction (XRD) analysis showed that the obtained nickel powder has face-centered cubic structure and the average crystallite size calculated by the Scherrer equation was ~ 34 nm. Calculations of activation energy were performed via processing of thermogravimetric data. The Kissinger method showed that the activation energy value decreases from 145.19 kJ/mol to 43.65 kJ/mol, by the Flynn-Wall-Ozawa (FWO) method the value decreases from 152.82 kJ/mol to 51.65 kJ/mol, and by the Coats-Redfern method the value decreases from 143.38 kJ/mol to 52.64 kJ/mol. Ap-plicability of these methods is ensured by the high values of correlation coefficients.