Vol 92, No 12 (2019)

Multidisciplinary conceptual approach to studying the friction in friction couples differing in the friction surfaces, their structure, structural organization in thin layers, lubricants, and loads in the contact zones using different methods for recording the sliding and rolling friction is presented. The possibility of controlling the boundary friction using deposited coatings and the orientation effect of these coatings on lubricating materials in friction couples was demonstrated. Application of diamond-like carbon coatings onto working surfaces of parts of heavy-duty friction units (engines, tooth gears, contacts between a metalworking tool and a part being machined, etc.) allows the content of additives in lubricating oils to be significantly reduced and thus the consumption of lubricating materials to be decreased, up to complete abandonment of the use of oils containing expensive or environmentally unfriendly additives.

Various implementations and various combinations of solvent deasphalting with the modern processes of deep oil refining are considered, and the ways of processing the separation products formed are demonstrated. Specific features of the main technologies used in Russia and other countries are discussed. Particular attention is paid to perspective technologies implementing the fuel direction of the process using both traditional hydrocarbon solvents and nontraditional solvents such as organic carbonates and carbon dioxide.

Thin films based on the SiO₂-P₂O₅-CaO and SiO₂-P₂O₅-CaO-MgO systems were obtained by the sol—gel method from solutions. The physicochemical processes underlying their production are investigated. The phase composition, structure, and biological activity of the obtained materials were studied. It was found that in order to obtain crystalline material when magnesium oxide is introduced into the SiO₂-P₂O₅-CaO system, a temperature increase of up to 800°C is necessary, and the addition of magnesium oxide to the SiO₂-P₂O₅-CaO system improves the bioactivity of the material.

The influence of the type of organic template from the series: pyrrolidine, dimethylformamide, N-methylpyrrolidone on the physicochemical properties of zeolite of MTT structure (ZSM-23) was studied. The optimal composition of the reaction mixture and the synthesis conditions of ZSM-23 were determined for each template. The use of relatively inexpensive organic templates, dimethylformamide and N-methylpyrrolidone, makes it possible to obtain phase-pure zeolite of MTT topology with SiO₂/Al₂O₃ ratio from 60 to 100, the acid characteristics of which are similar to zeolites obtained with pyrrolidine expensive and not produced in Russia. The synthesis with use of dimethylformamide allows obtaining zeolite ZSM-23 with a yield of more than 95% calculated in term of silica spent and improved texture characteristics: the micropore volume 0.08–0.09 cm³ g⁻¹, the total pore volume 0.3–0.35 cm³ g⁻¹. An analysis of the features of the syntheses with different templates exhibited that dimethylformamide can be considered as the most suitable for use in producing MTT zeolite (ZSM-23).

Results are presented of a study into the kinetics of thermal decomposition of a vulcanized mixed energy formulation K-2, the main components of which are ammonium perchlorate, octogene, aluminum, and inert binder, macromolecular cis-polybutadiene plasticized with transformer oil. In experiments with open crucibles, evaporation of the plasticizer, thermal decomposition of octogene and ammonium perchlorate successively occur in the samples. The dependence of the activation energy E on the conversion α is complicated: its minimum value (65 kJ mol⁻¹) corresponds to the evaporation of the plasticizer, and the maximum value (192 kJ mol⁻¹ at α ≈ 0.27), to the decomposition of octogene. At any hindrance to the free egress of decomposition products (packing of samples in an aluminum foil or the hermetical sealing), reactions occur in a “self-generated” atmosphere, and the type of K-2 decomposition changes. For samples in the foil, the exothermic peak of octogene is shifted to higher temperatures, the maximum of the activation energy (182 kJ mol⁻¹) corresponds to α ≈ 0.45, and the loss of mass by K-2 samples is complete at lower temperatures. Reasons for this transformation of the K-2 decomposition pattern are discussed.

Heat release kinetics in the reaction of thermal decomposition of 7-amino-7H-difurazano[3,4-b:3′4′-f] furoxano[3″,4″-d]azepine and a binary rocket propellant on its basis, suggested as a potential promising dispersing agent in the gas generator of propulsive jet engines. The fundamental kinetic aspects found in the study were used to calculate the time in which a certain degree of decomposition is reached at a prescribed set of temperature for solving the problem of applicability of the propellant under consideration for a particular article.

Composites based on polystyrene and asphaltenes isolated from heavy oil were produced by melt mixing. The content of asphaltenes in the composites was varied from 5 to 30 wt %. Partial solubility of asphaltenes in polystyrene was demonstrated. The undissolved part of asphaltenes forms in the polystyrene matrix aggregates up to tens of micrometers in size, which leads to a decrease in the tensile strength as compared with the unfilled polymer. Asphaltenes also serve as plasticizers for polystyrene lowering its glass-transition point.

The effect of carbon monoxide and hydrogen additions on partial gas-phase high-pressure oxidation of methane was studied experimentally. The maximum permissible concentrations of these components in the recycled gas were determined. The optimum multiplicity of the hydrocarbon gas recycling in the process was substantiated.

Trials of oxidative cracking of ethane—propane—n-butane mixtures were performed on an installation with the productive capacity with respect to the gaseous feed of 5 m³ h⁻¹. Ethylene, CO, and hydrogen are the major products of oxidative cracking of oil refinery gases; their total yield can exceed 90%. The yield of ethylene and CO is determined by the total concentration of alkanes in the mixture and is independent on the length of their hydrocarbon chain, whereas the hydrogen yield appreciably decreases with an increase in the alkane chain length. The trials demonstrated high efficiency of the production of ethylene, CO, and hydrogen by oxidative cracking of oil refinery gas mixture components.

The possibility of using [(C₄H₉O)₃P=O]₂ZnCl₂ as a catalyst for preparing cold-cured polyurethane from a mixture of hydroxyl-containing oligomers and polyisocyanate was examined. The kinetic characteristics of curing were studied by viscometry, and the physicomechanical characteristics of compounds synthesized in the presence of [(C₄H₉O)₃P=O]₂ZnCl₂ were determined. The influence of the curing rate on the structure of hydrogen bonds in the polymer matrix and on the glass transition point of the polyurethane was analyzed using Raman spectroscopy and differential scanning calorimetry. The results obtained show that curing of polyurethane in the presence of [(C₄H₉O)₃P=O]₂ZnCl₂ occurs at a high rate and leads to the formation of stronger intermolecular hydrogen bonds, which is accompanied by an increase in the strength characteristics and in the glass transition point of the ready material. The suggested mechanism of the formation of the regular three-dimensionally cross-linked structure of the multicomponent polyurethane and the revealed relationships between the rheokinetic parameters of the cold curing and the physicomechanical properties of the material synthesized in the presence of [(C₄H₉O)₃P=O]₂ZnCl₂ have no analogs among the known polyurethane composites.

Supported CoMoS and NiWS catalysts were synthesized on the basis of an Al₂O₃—SAPO-11 composite support. The acid and texture characteristics of the thus synthesized materials were examined. The morphologies of the active sulfide phase of the catalysts were compared. The kinetic properties of the supported sulfide catalysts in the reaction of hydroisomerization of n-hexadecane and in the hydroprocessing of the diesel fraction were examined. It was shown that it is possible to obtain hydrogenates with improved low-temperature properties in the presence of supported sulfide catalysts containing no noble metals.

Trimetallic NiCoMo catalysts supported on γ-alumina (γ-Al₂O₃), amorphous silicon dioxide (SiO₂), and mesostructured silicate (SBA-15) with equal surface concentration of active components were synthesized, and their physicochemical characteristics, including the morphology of the active phase particles, were studied. The performance of the synthesized catalysts in target hydrotreating reactions at different concentrations of an organic nitrogen-containing inhibitor, quinoline (0–1000 ppmw nitrogen), was determined. The inhibiting effect of quinoline on the hydrodesulfurization and hydrogenation reactions occurring on the synthesized catalysts and the influence of the kind and properties of the support on this effect were evaluated.

Colloidal stability of greases is one of the most important physicochemical parameters, which characterizes their working capacity and affects the mechanical strength and tribological properties. An integrated study of the colloidal stability of greases based on synthetic base oils with organic thickening agents demonstrated that the stability depends to a noticeable extent on quite a number of factors, such as the nature of a base oil and a thickening agent, presence of fillers, synthesis conditions, etc. A combination of these factors makes it possible to obtain greases with required colloidal stability.

The optimum loading on the iron-containing catalytic dispersion of the three-phase Fischer—Tropsch synthesis is 25 nL h⁻¹ when using an autoclave reactor. The linear velocity of the synthesis gas corresponds to 0.003 cm s⁻¹. Under these conditions, the following synthesis parameters were achieved: CO conversion of 80%, liquid hydrocarbon productivity 400 g kg Fe⁻¹ h⁻¹. Based on the data obtained, when modeling a column reactor for three-phase Fischer—Tropsch synthesis, the following unit dimensions were calculated: height 1.6 m, internal diameter 0.045 m.

Separation of olefin/paraffin mixtures is an important problem. The use of a gas—liquid membrane contactor is an attractive alternative to traditional power-consuming cryogenic distillation methods. The paper deals with the separation of ethylene from its mixture with ethane (component ratio 19/81 vol %, respectively) using an aqueous silver nitrate solution as a selective ethylene absorbent in a flat-sheet lab-scale membrane module equipped with an MDK-3 commercial composite membrane with the selective layer based on silicone rubber. The effect of the absorbent and gas mixture feed linear velocities on the residual ethylene content of the mixture is considered. The thin selective layer of the membrane is shown to preserve high performance during long-term experimental run ensuring high mass-exchange characteristics and preventing the absorbent penetration into the porous structure of the membrane support.

In the title section in the authors list Previslov should be replaced by Perevislov.

In the head of Table 7, column 3 row 2, Ln(III) should be replaced by Nd(III).