Cyclododecene cometathesis with hexene-1 on the MoCl<Subscript>5</Subscript>/SiO<Subscript>2</Subscript>–Me<Subscript>4</Subscript>Sn catalytic system

The stereochemistry of the cometathesis of cyclododecene (CDD) with hexene-1 in the presence of the MoCl₅/SiO₂–Me₄Sn heterogeneous catalytic system has been studied. It has been established that CDD is the mixture of cis- (Z) and trans- (E) stereoisomers with the ratio of 30/70, respectively. It has been shown that the reactivity of the E-stereoisomer of CDD in the reaction of cometathesis is higher when compared to the Z-stereoisomer. Thus, when the conversion of CDD is 92%, the ratio E/Z = 6 : 94, i.e., the amount of the E-stereoisomer decreases from 70 to 7%, while the amount of the Z-stereoisomer increases from 30 to 93%, respectively.     

Foil-supported Rh/γ-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> and Pt/γ-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> catalysts for carbon dioxide methane reforming

Rh/γ-Al₂O₃ and Pt/γ-Al₂O₃ catalysts supported on a metal foil surface have been studied in the carbon dioxide reforming of methane. The stability and activity of platinum and rhodium catalysts with different compositions have been determined. The kinetic function parameters have been found by solving the inverse problem. It has been shown that the 0.06% rhodium catalyst is the most active; its activity is more than two orders of magnitude higher than that of the nickel-chromium catalyst studied earlier.     

Hydroisomerization of reformed gasoline on the Pt/SO<Stack><Subscript>4</Subscript><Superscript>2−</Superscript></Stack>-ZrO<Subscript>2</Subscript> catalyst

The features of the hydroisomerization of C₅–C₁₂ alkane and aromatic hydrocarbons present in reformed gasoline over a catalyst based on platinum-promoted sulfated zirconium dioxide were studied.     

The formation features of C<Subscript>10</Subscript>–C<Subscript>20</Subscript> regular petroleum isoprenanes

To model the formation processes of C₁₀–C₂₀ petroleum isoprenanes, thermolysis of regular and irregular C₂₀–C₄₀ isoprenanes (phytane, crocetane, squalane, and lycopane) and the suggested precursors of regular petroleum isoprenanes (phytol and isophytol) has been conducted. It has been shown that the thermolysis of these compounds results in the formation of regular, irregular, and pseudoregular isoprenanes; the trends in their distribution have been revealed; and the retention indices have been determined. It has been assumed that the pristane/phytane ratio, which is used in petroleum geochemistry, should be treated with caution.     

Can Mesoporous TiO<Subscript>2</Subscript>-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-Supported NiMoS OR CoMoS Effectively Perform in Ultra-Deep Desulfurization of Gas Oil?

Waste aluminum foil was used for preparation of mesoporous TiO₂-Al₂O₃ using starch as a textural modifier. The catalytic species, Mo and Ni or Co were loaded onto the mesoporous support, following incipient wetness sequential impregnation. To gain an insight into the pore dimensions effect, Ni and Mo species with the same mass ratio were loaded onto the TiO₂-Al₂O₃, prepared from analytical grade chemicals without templating. TPR spectra, TEM images and BET analysis showed how the promoter (Ni or Co), TiO₂ and the template (starch) affect the ease of reduction of Mo species, the morphology of the active MoS₂ phase and the pore dimensions of the catalysts. The catalysts were employed in hydro-desulfurization process of gas oil using a fixed bed down flow microreactor at varying operating conditions, viz., temperature (320–400°C), Liquid hourly space velocity (0.5–4 h^–1), H₂/oil ratio of 450 v/v, and 6 MPa operating pressure. The results showed that the promotion effect prevails over the textural effect, where Ni promoted catalyst (with lower surface parameters) exhibits higher activity than Co promoted one. The dual layer catalytic bed system achieved the sulfur level less than 10 ppm.     

Partial Catalytic Oxidation of C<Subscript>3</Subscript>–C<Subscript>4</Subscript> Hydrocarbons on Pilot Scale

The process of partial catalytic oxidation of a propane–butane mixture with atmospheric oxygen in a pilot unit has been accomplished. Comparative tests with α-Al₂O₃-supported nickel catalysts and a pressed metal wire catalyst (PMC) made from 12Kh18N10Т steel wire of a 0.2 mm diameter have been conducted. In both cases, byproducts (СН₄, СО₂, and coke) are formed along with the target products (Н₂, СО). It has been shown that the compositions of the resulting synthesis gas are close; however, the Н₂/CO molar ratio is closer to 2 in the case of PMC catalyst, which meets the requirements of the subsequent Fischer–Tropsch synthesis. Problems associated with coking and complete degradation of the structure of the α-Al₂O₃-based catalysts have been revealed and explained in terms of the low efficiency of heat removal from the surface and the formation of carbon in micropores followed by its expansion. These phenomena are characteristic of 12Kh18N10T PMC to a substantially lesser extent and have a local character, suggesting that this catalyst holds promise for its further investigation.     

Oxidative dehydrogenation of butenes over Ni-V-Sb/γ-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> oxide catalyst

The process of the oxidative dehydrogenation of butenes over a nickel-vanadium-antimony supported catalyst proceeds with a higher conversion and selectivity as compared to the dehydrogenation of n-butane. It was found that the maximum yield of divinyl per pass from the butylene fraction reaches 44% at a 68% selectivity. The maximum selectivity of the process (75%) is achieved at a divinyl yield of no more than 40%. The addition of nickel oxide to antimony vanadate results in the simultaneous formation of both nickel vanadate and antimonate, which are responsible for the conversion of butylenes to divinyl. Systems based on the supported Ni-V-Sb oxide matrix were analyzed with the use of the BET, X-ray photoelectron spectroscopy, diffuse reflection spectroscopy, X-ray diffraction, and hydrogen temperature-programmed reduction techniques. The formation of the NiV₂O₆ nickel vanadate phase results in the most selective catalyst with an increased amount of mobile oxygen in the lattice due to the presence of vanadium.     

Formation of WO<Subscript> <Emphasis Type="Italic">x</Emphasis> </Subscript>–ZrO<Subscript>2</Subscript> isomerization catalysts from anion-modified zirconium hydroxide

The formation of zirconia-based isomerization catalysts during thermal conversions of hydroxide modified with different amounts of tungstate groups has been studied by differential scanning calorimetry and X-ray diffraction analysis. The mechanism of formation of tungstated zirconia from a hydroxide precursor has been formulated.     

A study of Pt/WO<Subscript>4</Subscript><Superscript>2−</Superscript>/ZrO<Subscript>2</Subscript> catalyst deactivation in the hydroisomerization of heptane and a heptane–benzene mixture

The dynamics of the catalytic properties of a Pt/WO₄ ^2?/ZrO₂ catalyst (17 mol % WO₄ ^2?) in the hydroisomerization of heptane and a heptane–benzene mixture as a function of reaction time and temperature has been studied. It has been found that the heptane conversion decreases in the initial reaction period (within 2 h) and the isohexane selectivity symmetrically increases at 170–280°C, with the benzene hydrogenating activity decreasing at 250°C and higher temperatures. The observed changes in catalytic properties are attributed to the partial deactivation of both the acid and hydrogenation components of the catalyst. X-ray photoelectron spectroscopy has revealed the formation of carbon deposits on the catalyst surface; the structure of the deposits is determined by the reaction medium composition. The composition of the products formed on the catalyst after heptane hydroisomerization is mostly represented by aliphatic polymers of the “poly-С_хН_y” type, which are capable of blocking the active sites that catalyze the cracking reactions. The addition of benzene to heptane has led to the formation of graphite-like carbon deposits; this feature is apparently responsible for a decrease in both the acidity and hydrogenation activity of the catalyst. The phase state and textural characteristics of the catalysts are stable under the isomerization reaction conditions.     

Conversion of C<Subscript>6</Subscript>–C<Subscript>10</Subscript><Emphasis Type="Italic">n</Emphasis>-alkanes on the polyfunctional catalyst KT-22

The conversion of C₆-C₁₀ n-alkanes on the zeolite-containing catalyst KT-22 was studied. It was shown that hydrocarbon conversion on the catalyst follows a complex mechanism—there are parallel and consecutive reactions of dehydrogenation, hydrocracking, hydroisomerization, dehydrocyclization, hydrogenation, and alkylation that simultaneously proceed. The catalyst KT-22 shows multifunctional properties. The catalyst selectivity depends on the conditions of the process.     

Generation of C<Subscript>11</Subscript>–C<Subscript>17</Subscript> monoalkyladamantanes via catalysis of some oxygen-containing precursors of petroleum hydrocarbons

Oxygen-containing compounds that are known to be precursors of petroleum hydrocarbons have been subjected to catalysis on an aluminosilicate catalyst. It has been found for the first time that along with C₁₁–C₁₂ monoalkylated adamantanes, which are typically present in crude oils, the homologous series of 1- and 2-n-alkyladamantanes up to and including n-heptyladamantanes are generated via the catalysis (monoalkyl-substituted adamantanes with a substituent heavier than the ethyl radical have never been found in any crude oil). It has been shown that, with the increasing degree of conversion, C₁₃–C₁₇ adamantanes disappear and only 1- and 2-methyl- and ethyladamantanes remain in the catalyzates. The absence of high-molecular alkyladamantanes (C₁₃ and higher) in crude oils is supposedly attributed to relatively high maturity of crude oil.     

High-octane additives for automobile gasoline based on С<Subscript>1</Subscript> and С<Subscript>2</Subscript> alcohols and butane–divinyl fraction from the pyrolysis process

Coalkylation of the the butane-divinyl pyrolysis fraction with C₁ and C₂ monohydroc alcohols has been studied. The product composition of the alkylation has been determined. It has been shown that the products can be used as high-octane components of motor gasoline along with methyl tert-butyl ether, tert-amyl methyl ether, and other oxygenates.     

Epoxidation and oxidative dihydroxylation of C<Subscript>10</Subscript>–C<Subscript>13</Subscript> unsaturated bridged hydrocarbons involving hydrogen peroxide and modified forms of heteromolybdic compounds

Induced oxidation of C₁₀–C₁₃ tricyclic bridged olefins synthesized from C₅–C₈ cyclodiene hydrocarbons using hydrogen peroxide has been studied. It has been shown that phosphomolybdic heteropoly compounds supported on a finely divided carbon material and additionally modified with HBr and CoCO₃ or Gd₂O₃ exhibit high activity in this reaction. Depending on the conditions of the experiments, the main reaction products are the corresponding oxiranes and diols that retain the structure of the reactant hydrocarbons.     

Acid Properties of the Surface of Zn–B–P/γ-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>/Al Catalysts and Their Activity in Microwave-Stimulated Reaction of Diethylamine Acylation with <Emphasis Type="Italic">m</Emphasis>-Toluic Acid

The acid–base properties of Zn–B–P/γ-Al₂O₃/Al catalysts for the direct acylation of diethylamine with m-toluic acid have been studied using ammonia temperature-programmed desorption, probe adsorption, and IR spectroscopy techniques, the catalysts having been synthesized and tested under conditions of microwave-assisted thermal treatment. A correlation between the activity of the microwave-absorbing catalysts in the target N,N-diethyl-m-toluamide formation reaction and the concentration of acid sites of medium strength on the surface of the samples has been revealed. It has been shown that the main reason behind the higher activity of Zn–B–P/γ-Al₂O₃/Al catalysts prepared under conditions of the thermal action of microwave field is the formation of a more developed active surface characterized by a prevalence of medium acid sites.     

Olefin Synthesis from Dimethyl Ether in the Presence of a Hydrothermally Treated Mg–HZSM-5/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Catalyst: Effect of Reaction Conditions on the Product Composition and Ratio

Systematic studies of olefin synthesis from dimethyl ether (DME) in the presence of a hydrothermally treated HZSM-5 zeolite catalyst modified with magnesium have been conducted. Dependences of DME conversion, product yield and selectivity, and lower olefin ratio on space time in the temperature range of 320–360°C have been analyzed. The type of the resulting products has been determined, and assumptions about the reaction chemistry have been made to reveal the role of methylation and hydrogen-transfer reactions in the products formation.     

Correlation of basic <Superscript>1</Superscript>H and <Superscript>13</Superscript>C NMR-measurable structural group parameters of crude oils of the Volga–Urals oil and gas basin

Among 120 pairwise relations between 16 main ¹H and ¹³C NMR-measurable characteristics of the structural group composition of Volga–Urals crude oils, 10 most consistent relations (correlation coefficients |r_s| ≥ 0.9), 13 relations with |r_s| in the range of 0.8–0.9, and 33 pairs with loosely related or mutually independent members (|r_s| ≤ 0.3) have been revealed. Several relationships are parametric. The main parameter is C_ar. The overall picture of the relationships is complex; correlation coefficients with the absolute value above 0.7 are observed not only between the parameters characterizing the structure in the same group of entities (aromatic, n-alkyl): it has been found that C_ar correlates with the total content of n-alkyl structures (r_s =–0.76). Having definitely common features, oils from the Volga–Urals and Western Siberia oil and gas basins noticeably differ from one another. To explain the differences, it is necessary to launch an integrated study that is methodologically beyond the scope of contemporary petroleum geochemistry. The paper demonstrates the capabilities of correlation analysis for solving problems to which this method has not been yet applied in petroleum geochemistry: partial correlation coefficients as a means of identifying parametric relationships and Spearman correlation coefficients for nonnumeric values in determining differences in the composition between oils of different structures and from different territories or stratigraphic plays.     

Correlation between main structural group parameters of crude oils of the Volga–Urals oil and gas basin by <Superscript>1</Superscript>H and <Superscript>13</Superscript>C NMR data

In Volga?Urals crude oils, an increase in the aromatics content is characterized by a rapid increase in the relative amount of polysubstituted aromatic rings and a generally lower proportion of bi- and polycyclic aromatics, unlike the case of Western Siberia oils. The difference between the oil and gas basins is most probably due to the special features of the source organic matter of the oils. The regional features of the Volga?Urals oils are a relatively weak relationship between the concentrations of mono- and bi- + polycyclic aromatics and a relatively close relation of Σn-Alk to typically uninformative parameter Hβ, which indicate a high uniformity of the composition of saturated cyclic compounds and moieties of hybrid naphthenoaromatic components. In addition, the assumption that (H/C)_ar/(H/C)_al = const does not hold for Volga?Urals oils. However, the relationships between the main parameters describing total aromaticity (primarily, C_ar, H_ar) and n-alkyl structures (primarily, Σn-Alk) are identical for oils from both the basins. The total number of relationships that can be universal for oils from different oil-and-gas basins is fifteen. To estimate C_ar from ¹H NMR data for Volga?Urals crude oils, a linear dependence on the two variables H_ar and H_α should be used. The expressions obtained to relate the structural-group parameters have made it possible to reveal a number of oils that stands out among the others.     

Synthesis and properties of quaternary ammonium salts based on <Emphasis Type="Italic">N,N′</Emphasis>-tetramethyldiaminomethane and 4-chloro-2-pentene

Quaternary ammonium salts based on N,N′-tetramethyldiaminomethane—an intermediate product in the manufacture of ionol (2,6-di-tert-butyl-4-methylphenol)—were synthesized. Their optimal preparation conditions were found. The constitution of the compounds was established and their main physicochemical and inhibitory properties were investigated.