Vol 56, No 7 (2016)

Current ideas concerning oil rheology, in particular, that of heavy oils and water–oil emulsions have been considered. It has been shown that petroleum in general is a viscoplastic medium, whose rheological properties in many cases are satisfactorily described in terms of the simple Bingham model. Typical characterization of rheological properties reduces to measurement of the yield point and the pour point and to conditional values obtained by measuring viscosity in viscometers of various types. However, both the yield stress and plastic viscosity are structurally sensitive, resulting in dependence of the rheological properties of oil on the temperature and deformation history, including the kinetics of cooling, which is characterized by a hysteresis curve in the measurement of viscosity. The kinetics of change in the rheological properties of oil depends on the concentration of crystallizable paraffins and other components. Rheology is modified largely by introducing pour point depressants into the oil. Another method for controlling the rheological properties of oil is to convert it into the state of water–oil emulsion using various surfactants. The general formulation of the problem of pipeline oil transport has been discussed, involving calculation based on the knowledge of both the rheological properties of oil and the kinetics of transient structuring processes. The latter is especially important for start-up modes of pipeline operation.

Genetic diagnostics of hydrocarbon systems of different origins—hypergenetically altered (biodegraded) and immature fluids—has been performed in terms of hydrocarbon (HC) and trace element (TE) indicators. Among more than 30 hydrocarbon compounds and more than 10 trace elements, informative and universal discrepancy criteria have been selected. These are the 20S/(20S + 20R) and ββ/(ββ + αα) C₂₉ sterane ratios; the diasteranes/regular steranes ratio; and the oleanane/C₃₀ hopane (H₃₀), moretane/H₃₀, and gammacerane/H₃₀ hydrocarbon biomarker ratios. Type assignment of crude oils in terms of trace element content has revealed significant differences of hypergenetically altered oils in the total cycle of naphthidogenesis and showed that they are oils of secondary enrichment with trace elements (V/Ni > 1), creating vanadium metallogenic provinces with hydrocarbon deposits enriched in V, Ni, U, Mo, etc. at a commercially viable level.

Abstract—Colloidal properties of model and actual feedstock and methods to control them in production of carbon black (CB) have been studied. The role of surface phenomena during formation of CB properties has been determined. Methods and approaches to control the concentration and size of the dispersed phase in the feedstock by external actions have been considered. Dependences of the CB quality on the colloidal properties of the raw materials have been determined. The results have been applied in industrial conditions.

An approach to the construction of a kinetic model for the reactions of rapeseed oil hydroconversion to aromatic hydrocarbons has been proposed, which is based on analysis of experimental data obtained using a MFI zeolite promoted with zinc and chromium ions. An empirical mathematical model describing the dynamic behavior of the main products of the decomposition reaction of rapeseed oil as a model feedstock has been developed. It has been shown that an increase in the space time and temperature in the examined range of reaction conditions increase the yield of aromatic hydrocarbons. The influence of hydrogen pressure on the yield of aromatics is nonmonotonic in character, passing through a maximum, with the optimum yield being in the middle of the hydrogen pressure range of 10–20 atm.

The evolution of the structure of Pt–Sn/Al₂O₃ catalysts and their catalytic properties in the reaction of the reductive deoxygenation of rapeseed oil fatty acid triglycerides (FATGs) have been studied. The catalysts were prepared by deposition from an organic solution of a mixture of platinum and tin compounds, as well as a heterometallic (PPh₄)₃[Pt(SnCl₃)₅] complex, in which platinum and tin atoms are linked by a metal–metal bond. It has been shown that the use of the heterometallic complex as a precursor with a tin to platinum molar ratio of 5 results in the formation of clusters of nanosized tin (2+; 4+) oxides and particles of a metastable PtSn_{3 ± δ} alloy on the surface of the catalyst after reductive activation. In the presence of this catalyst, the exhaustive conversion of the feed FATGs and the selectivity for hydrocarbons above 98% have been achieved. The gaseous products CO, CO₂, and CH₄ are formed in trace quantities. The results show that the deoxygenation occurs not via the known decarboxylation and decarbonylation route, but also through the step of the selective reduction of oxygen and almost complete suppression of cracking of the organic moieties of FATGs.

Potential use of ultrahigh-resolution mass spectrometry for determination of sulfur-containing components of petroleum before and after ozonation has been described. The chemical composition of the petroleum before and after ozonation has been determined using a Fourier transform ion-cyclotron mass spectrometer with soft ionization techniques: atmospheric-pressure photoionization and positive- or negative-ion electrospray ionization. The article presents the main trends of change in the composition of petroleum sulfur components in the ozonation process as revealed on the basis of ultrahigh-resolution mass spectra.

HY zeolite catalysts on montmorillonite, pillared with aluminum hydroxo complexes in different concentrations, have been tested in the cracking of heavy vacuum gas oil (VGO) from the Shymkent refinery (Kazakhstan). It has been shown that the VGO cracking activity of the catalysts is directly related to the textural and acid properties of the samples. The hydrocarbon group and fractional compositions of cracked gas-oline have been determined.

Carboxylation of o-cresol, m-cresol, and p-cresol with sodium ethyl carbonate (SEC) proceeds regioselectively with the formation of cresotic acids: 2-hydroxy-3-methylbenzoic acid, 2-hydroxy-4-methylbenzoic acid, and 2-hydroxy-5-methylbenzoic acid, respectively. Optimal conditions for conducting the process have been found to be as follows: the reactants ratio of [cresol]: [sodium ethyl carbonate] = (1.5–2): 1, T = 180–185°C, \({P_{C{O_2}}}\) = 10 atm, and t = 6–7 h. Simple and convenient methods for the synthesis of cresotic acids, which can be used for their industrial manufacturing, have been developed.

The feasibility of biochemical oxidation of a mixture of polyaromatic hydrocarbons (PAHs) in the absence of other sources of carbon and energy by the community of hydrocarbon-oxidizing bacteria (HOB) of Pseudomonas stutzeri, Pseudomonas putida, Bacillus cereus, and Arthrobacter globiformis species has been shown. The population of microorganisms has increased from 0.25 × 10⁴ to 11 × 10⁸ CFU/mL of medium during culturing, accompanied by an increase in their oxygenase activity. All the identified PAHs have undergone oxidation: the degree of degradation of biarenes, triarenes, tetraarenes, pentaarenes, and hexaarenes and their methylated homologues has varied from 11.3 to 100%.