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The results of research of changes in the quality of motor oils by oxidation at temperatures up to 200 °C in the presence of diesel fuel fractions are presented. The purpose of the research is to assess the working life of motor oils contaminated with various concentrations of diesel fuel. The research was carried out by the method of oxidation of motor oils under the influence of high temperatures. This method performs artificial aging of fresh motor oils with specified parameters for further research of changes in their properties. The result of the research was to obtain data on changes in the quality indicators of motor oils contaminated with various concentrations of diesel fuel. This research can be the basis for developing recommendations for improving the maintenance of internal combustion engines to assess the performance of fuel system elements in order to increase the resource of power units and reduce operating costs. [ABSTRACT FROM AUTHOR]

Bitumen is organic binder consisting of highly molecular hydrocarbons: naphthenic, methane and aromatic, as well as oxygen, sulfur and nitrogen derivatives. Petroleum bitumen is obtained at oil refineries. It is a complex mixture of high-molecular hydrocarbons. The greatest use of bitumen is found in road construction. In the course of research, theoretical calculations and experimental confirmation of changes in the properties of bitumen when adding carbon nanotubes were made. It is established that the main mechanism for changing the properties of a mixture based on bitumen reinforced with a carbon nanomaterial is the adsorption interaction of the main components of bitumen (naphthene and anthracene) with the external surface of a carbon nanotube at a perpendicular location of the component molecule relative to the surface. Three concentrations of carbon nanotubes were tested: 0.1%, 0.01%, 0.001% in a bitumen mixture, as well as a reference sample without adding carbon nanotubes to compare changes in indicators. Based on the research conducted in the course of this work, it can be stated that the proposed method of strengthening the asphalt concrete coating by reinforcing the main component of the coating – bitumen – improves its physical and mechanical properties and, accordingly, increases the service life of the roadbed. [ABSTRACT FROM AUTHOR]

This article is devoted to the analysis of arising transient effects in rectification unit operation parameter control systems. Mutual influence of transition processes in hydraulic units and heat exchange units leading to the rectification column operation destabilization is shown. A regulatory control system malfunction connected with the inconsistency of characteristics of new efficient heat exchange equipment and regular centrifugal pump is discussed using practical experience of operation the 1,3-butadiene extraction and purification unit. The coordination and stabilization diagram of hydraulic and heat exchange processes in the rectification control system is described. [ABSTRACT FROM AUTHOR]

The investigation is made on the phase behavior of the surface-terminating oxygen layer on MXene V2C sheet using the methods of density functional theory (DF)T and statistical physics. Two approximations of the potential of lateral interactions between adsorbed oxygen atoms are constructed. The first approximation is the pair potential form. The second approximation is constructed by the Cluster Expansion (CE) method. As expected, quantitative estimations of approximation errors show that the CE approximation is more accurate, but the pair potential also turns to be of comparable accuracy. Then, adsorption isotherms are calculated using statistical physics algorithms implemented in the SuSMoST code. The isotherms reveal nontrivial phase behavior of the oxygen layer: three phases with coverages of ⅓, ½ and ⅔ monolayer are discovered. From free energy calculations, it is predicted that complete cleaning of the V2C surface from oxygen is possible at temperatures above 2500 K and at partial pressure below 10−9 bar. At atmospheric pressure in air, a complete oxygen coating is stable at temperatures up to 2700 K. Phases with intermediate coverages are stable at temperature below 1200 K and probably could be observed only at ultra-low partial pressure of oxygen. [ABSTRACT FROM AUTHOR]

Isomerization of heptane, hexane and their mixture in the presence of Pt/WO3-ZrO2 catalysts was studied. The content of tungsten oxide in the catalysts was varied from 15 to 30 wt.%. It was shown that C6-C7 alkane hydrocarbons are efficiently isomerized in the presence of Pt-containing tungstated zirconia catalysts, both in the case of individual components (heptane and hexane) and their mixture (heptane/hexane=70/30 (wt.%)). Simultaneous isomerization of heptane and hexane over Pt/WO3-ZrO2 catalysts with the tungsten oxide content 15-20 wt.% at 220°C provided the conversion of heptane 91.4-91.5% and hexane 76.6-77.4% at the yield of stable catalyzate 79.3-82.2 wt.%. Therewith, the yields of high-octane dimethyl and trimethyl substituted isomers of heptane (DTMS) and isomers of hexane – dimethylbutanes (DMB) were 25.4-26.9 and 19.7-20.3 wt.% as referred to individual components (heptane and hexane, respectively). [ABSTRACT FROM AUTHOR]

Cleanser with sufficient washing ability to remove complex contaminants from the surface of aluminum molds, which is used in the manufacture of rubber products, is developed. The composition of the product includes the following components: sodium hydroxide (8%), sodium carbonate (54%), sodium polyphosphate (15.6%), carboxymethylcellulose (1.6%), sodium silicate (4.8%), nonionic surfactant "Neonol AF 9-12" (11.2%) and cationic surfactant "Catamine AB" (4.8%), as a percentage of the mass of all detergent components. Sodium benzoate (mixed type of inhibitor) is proposed to prevent corrosion of the aluminum alloy in the process of removing contaminants. The optimal concentration of sodium benzoate is 0.7% by weight of the detergent solution; the degree of corrosion protection is 85.1%. [ABSTRACT FROM AUTHOR]

The possibility of using methods for statistical processing of experimental data obtained during the pyrolysis of a propane-butane mixture in a format that does not allow automatic processing is shown. Software has been developed and implemented that allows data to be translated into a format that is convenient for machine processing. Based on the analysis of the experimental data thus treated, 13 most common components are identified and assumptions are made about the necessary composition of liquid products. [ABSTRACT FROM AUTHOR]

The article reviews the potential use of hydrate formation for enriching natural gas with C2-C4 methane homologues. It is shown that when hydrates are formed in distilled water, the concentration of C2-C4 components in the gas transferred to hydrate increases 2.5 times, compared with the source gas. It is also shown that the use of 5% sodium chloride solution as a hydrate medium leads to an increased content of these components in the hydrate by 57.5%, compared with the hydrate formed in distilled water. It was found that with the hydrate formation method, the coefficient of gas enrichment efficiency for hydrates formed in the sodium chloride solution was 76.8%, which is 10 percentage points higher than that of the hydrates formed in distilled water. [ABSTRACT FROM AUTHOR]

The article presents the results of a thermodynamic calculation of the coal gasification process with steam, depending on the operating parameters (temperature and carbon-to-steam ratio). The results of determining the composition of the synthesis gas are in good correlation with the data of other authors – the maximum discrepancy is ± 0.5 abs. %. At β = 0.25, H2/CO exceeds 2, which allows the use of reaction products as raw materials for the production of methanol, 1,4-butanediol, or oxynthesis products. For β = 0.50 and β = 0.75, a similar picture is observed only up to 627-827 °C, and in the range of higher temperatures the products are suitable for the production of methyl methacrylate and dimethyl ether. [ABSTRACT FROM AUTHOR]

This paper presents a method for extracting rare earth element (REE) concentrate from spent catalysts of fluid catalytic cracking (SFCC) using the method of sulfuric acid leaching of a mixture of SFCC and NH4F. The optimal conditions for obtaining the concentrate are an excess of H2SO4 (1.3 times), the experiment duration of 40 minutes, and an excess of NH4F (1.3 times). The XRD, IR spectroscopy, scanning electron microscopy with EDX analysis, and atomic absorption spectroscopy were used. The resulting concentrate contains REE in the form of fluorides, their content increases by 3–9 times. Physicochemical methods of analysis detect REE fluorides, Topaz, and SiO in the concentrate. The ratio of cerium:lanthanum in thr concentrate is higher than in SFCC because lanthanum is extracted into solution as a sulfate. [ABSTRACT FROM AUTHOR]

The liquefaction of sapropel in the East Siberian region using ethanol under supercritical conditions (260 °C, 18 MPa) was studied. The influence of the hydrogen atmosphere and the CoMo/Al2O3 catalyst on the yield and composition of liquid products was established. The presence of a reactive hydrogen atmosphere and a catalyst increased the conversion of organic mass of sapropel (α) from 41.1 to 75.9 wt.%. Gas chromatographic–mass spectrometry, FT-IR, and NMR spectroscopy methods have shown that the bulk of liquid liquefaction products are esters (30.1−46.6 rel.%), alkyl derivatives of phenol (9.5−21.6 rel.%), and nitrogen-containing compounds (12.9−18.9 rel.%). The addition of hydrogen and a catalyst reduces the content of heteroatomic compounds in liquid products and increases the hydrogen content from 7.26 to 8.86 wt.%. The component composition of liquid products of liquefaction in supercritical ethanol was studied. It was shown that the introduction of a catalyst and hydrogen increases the yield of oils in the maltene fraction by 1.5 times. Structural-group analysis of liquid products showed that the average molecule is characterized by a low molecular weight MW = 200 amu. and contains 11 carbon atoms. The average molecule contains 1 aromatic ring with alkyl substituents and 2 oxygen atoms. The sulfur content is low, about 3 atoms per 100 average molecules. [ABSTRACT FROM AUTHOR]

Bimetallic catalysts Au-Pt/γ-Al2O3 were synthesized by wetness co-impregnation of alumina with aqueous solutions of H2PtCl6 and HAuCl4 in the presence of competing acids (HCl and CH3COOH). The platinum content in the samples was ∼ 0.5 wt.%, gold content was varied from 0.12 to 0.30 wt.%. The introduction of gold into catalyst Pt/γ- Al2O3 does not lead to a significant change in the qualitative and quantitative composition of Lewis acid sites of alumina. According to the transmission electron microscopy the average platinum particles size is 1.2 nm on the platinum-alumina catalyst surface. Conglomerates 6-30 nm in size are present on the surface of catalyst Au-Pt/γ-Al2O3 with gold content 0.30 wt.%. The modification of the platinum-alumina catalyst with gold leads to a decrease in the electron deficiency and dispersion of platinum. The quantity of chemisorbed methane on modified catalysts in two times less than on the surface of the platinum-alumina catalyst. It is connected to decrease in dispersion and electron deficiency of platinum. Catalysts Au-Pt/γ-Al2O3 were studied in the non-oxidative co-conversion of activated methane forms with n-pentane at 823 K. The modification of the Pt/γ-Al2O3 catalyst with gold leads to a decrease in the yield of aromatic hydrocarbons (benzene and toluene) from 22.2 to 16.4 wt.%. [ABSTRACT FROM AUTHOR]

The carbocatalyst was obtained by mechanical activation of carbon black P399 at the grinding bodies acceleration of 100 g in an oxidizing environment. It was shown that the carbocatalyst had the dibutyl phthalate absorption number of 140 ml/100 g, the specific surface area was 1054 m2/g, and the number of oxygen-containing groups on the carbon surface was 0.23 meq/g. The catalyst was tested in the oxidative dehydrogenation of ethane at different amounts of oxygen in gas mixture. It was shown that an increase in the content of free oxygen in the gas mixture from 1 to 2% contributed to an increase in ethylene selectivity of 15.65 and 25.74%, respectively. [ABSTRACT FROM AUTHOR]

The paper shows the possibility of processing benzene and toluene containing a gasoline fraction obtained under conditions of fuzzy rectification of the reforming product in the process of hydroisomerization. The octane loss caused by the presence of toluene in the feed can be made up by saturating the product with butane. The Pt/Al2O3-BEA catalyst showed steady and stable operation in the resource tests on this fraction. [ABSTRACT FROM AUTHOR]

In this work, using the lattice model of terephthalic acid (TPA) and iron metal–organic networks on the Cu(100) surface, the effect of point defects of the metal surface on thermal stability of two representative structures have been estimated. The influence of both the fraction of defects and their type (positive or negative in terms of change of the binding energy) have been investigated. For the surfaces with high energetic heterogeneity, when the difference between the adsorption energies on a defect and adsorption site is comparable with the energy of coordination interactions in the system, ordered structures can be observed up to 2–10% of defects depending on their type. In this case the surface heterogeneity significantly affects the critical temperature of the phases. For the surface with low energetic heterogeneity, when the above-mentioned energy difference is comparable with the TPA–TPA lateral interactions, ordered structures exist up to 40–50% of defects. In this case, the surface heterogeneity does not significantly affect the critical temperature of the phases. When the fraction of defects is up to 10–20% and 10–40%, the self-assembly of the "cloverleaf" and "single-row" phases and its critical temperatures is not significantly affected. Since point defects are often presented on real surfaces, the results can be useful in creating adsorption layers consisting of TPA molecules and metal atoms on heterogeneous metal surfaces. [ABSTRACT FROM AUTHOR]

The effect of fluorine introduction into the catalysts based on beta and mordenite-type zeolites on their textural, structural and acidic properties and catalytic performance in isomerization of n-hexane was studied. The introduction of fluorine was shown to decrease the amount of acid sites detected by ammonia TPD in the temperature range of 100-500 °C. It was found that fluorine-containing catalysts based on beta and mordenite zeolites are more selective toward the formation of mono- and dimethyl-substituted isomers of hexane and provide a higher yield of C5+ hydrocarbons as compared to undoped systems. [ABSTRACT FROM AUTHOR]

It is shown that treatment of Sibunit at 2200 °C leads to a full restructuring of the structural and textural parameters of the carbon support. The structure of Sibunit becomes more ordered – according to the XRD, the interplanar distance d002 decreases by 0.005 nm compared to the original Sibunit; according to the Raman spectroscopy, ID/IG decreases from 1.59 to 1.18 and the 2D-line increases significantly. The specific surface area of Sibunit after heat treatment decreases from 303 to 29 m2/g, the total pore volume decreases by 2 times, and the pore diameter increases by 4 times. The dependence of the specific activity on the amount of the active component is extreme, and the maximum for the 1%Ru-3.4%Cs/Sib2200 catalyst and is 1.52 mol NH3/gRu*h. [ABSTRACT FROM AUTHOR]

A sequence of steps in the synthesis of supported Pt/SO4/ZrO2/Al2O3 catalysts was studied. The introduction order of the active component was shown to substantially change the catalytic properties in isomerization of n-hexane. The sequence of introducing the components, their concentration, and the number of support impregnations make it possible to provide high performance in isomerization of n-hexane in the presence of supported sulfated zirconia catalysts. [ABSTRACT FROM AUTHOR]

This research studies the chemical composition of drilling sludge from the Nivagal oil field by the method of X-ray fluorescence spectrometry. We revealed a high chlorine content, which is presented in two configurations: natural and anthropogenic. A technique for cleaning the drilling sludge water extract from chlorine ions has been developed. Two methods for precipitating chloride ions are shown. The first method presupposes adding the nitric acid and silver nitrate. As a result, an acidic medium is formed in a purified solution. The second method is to add the ammonium hydroxide and silver nitrate to obtain an alkaline medium in a purified solution. The use of the second method is justified and a technological scheme of residual matter electrolysis is developed. During electrolysis, the extraction of free silver and free chlorine is shown. They can be further used in industrial production for various purposes. [ABSTRACT FROM AUTHOR]

The work shows the methods for the presentation and interpretation of data on the mechanical strength of heterogeneous catalysts and supports. The importance of observing the required sample size and the inadmissibility of interpretation of point values as a characteristic of the universal set is shown. With a sufficient sample size of the strength characteristics of the catalysts, their interpretation should be based on an interval estimate rather than a point estimate. [ABSTRACT FROM AUTHOR]