During the oxidation of hydrocarbons using hydrogen peroxide solutions, the evolution of gaseous oxygen is a side and undesirable process, in which the consumption of the oxidizer is not associated with the formation of target products. Therefore, no attention is paid to the systematic study of the chemical composition of the gas and the mechanisms of its formation. Filling this gap, the authors discovered a number of new, previously unidentified, interesting facts concerning both gas evolution and the oxidation of hydrocarbons. In a 33% H2O2/Cu2Cl4·2DMG/CH3CN system, where DMG is dimethylglyoxime (Butane-2,3-dione dioxime), and is at 50 °C, evidence of significant evolution of gaseous hydrogen, along with the evolution of gaseous oxygen was found. In the authors’ opinion, which requires additional verification, the ratio of gaseous hydrogen and oxygen in the discussed catalytic system can reach up to 1:1. The conditions in which only gaseous oxygen is formed are selected. Using a number of oxidizable hydrocarbons with the first adiabatic ionization potentials (AIPs) of a wide range of values, it was found that the first stage of such a process of evolving only gaseous oxygen was the single electron transfer from hydrogen peroxide molecules to trinuclear copper clusters with the formation, respectively, of hydrogen peroxide radical cations H2O2•+ and radical anions Cu3Cl5•− (AIP = 5 eV). When the conditions for the implementation of such a single electron transfer mechanism are exhausted, the channel of decomposition of hydrogen peroxide molecules into gaseous hydrogen and oxygen is switched on, which is accompanied by the transition of the system to an oscillatory mode of gas evolution. In some cases, the formation of additional amounts of gaseous products is provided by the catalytically activated decomposition of water molecules into hydrogen and oxygen after the complete consumption of hydrogen peroxide molecules in the reaction of gaseous oxygen evolution. The adiabatic electron affinity of various forms of copper molecules involved in chemical processes is calculated by the density functional theory method.

The oxidation of hydrocarbons of different structures under the same conditions is an important stage in the study of the chemical properties of both the hydrocarbons themselves and the oxidation catalysts. In a 50% H2O2/Cu2Cl4·2DMG/CH3CN system, where DMG is dimethylglyoxime (Butane-2,3-dione dioxime), at 50 °C under the same or similar conditions, we oxidized eleven RH hydrocarbons of different structures: mono-, bi- and tri-cyclic, framework and aromatic. To compare the composition of the oxidation products of these hydrocarbons, we introduced a new quantitative characteristic, “distributive oxidation depth D(O), %” and showed the effectiveness of its application. The adiabatic ionization potentials (AIP) and the vertical ionization potentials (VIP) of the molecules of eleven oxidized and related hydrocarbons were calculated using the DFT method in the B3LYP/TZVPP level of theory for comparison with experimental values and correlation with D(O). The same calculations of AIP were made for the molecules of the oxidant, solvent, DMG, related compounds and products. It is shown that component X, which determines the mechanism of oxidation of hydrocarbons RH with AIP(Exp) ≥ AIP(X) = 8.55 ± 0.03 eV, is a trans-DMG molecule. Firstly theoretically estimated experimental values of AIP(trans-DMG) = 8.53 eV and AIP(cis-DMG) = 8.27 eV.

Asphaltenes, which are macromolecular compounds contained in heavy oils, tend to aggregate and precipitate, thereby causing a number of problems during oil transportation and refining. The tendency toward aggregation is primarily manifested by molecules with the continental architecture, while asphaltenes with the archipelago molecular structure, on the contrary, contribute to the stability of the petroleum fluid. Selective removal of the continental asphaltene fraction from the oil reduces deposit formation and viscosity, thereby mitigating the problems in oil transportation, storage, and processing. In this study, the possibility of using polyacrylonitrile membranes for the selective separation of continent type asphaltenes prone to aggregation from their archipelago molecules has been explored. For this purpose, the filtration separation of solutions of asphaltenes and fuel oil in toluene has been studied using membranes with a pore size larger than the size of asphaltene molecules. It has been shown that during filtration through such membranes, agglomerates of molecules rather than individual species are retained. With a relatively low total membrane rejection of 35–67%, this makes it possible to effectively separate continental asphaltenes prone to agglomeration, for which the rejection reached 90%, from the archipelago-type molecules. The maximum difference between the membrane rejections of the continent and archipelago molecules has been observed at low concentrations of asphaltenes, so that the most efficient separation of the components can be achieved. At the same time, significant membrane fouling has been observed in the case of filtration of solutions of M-100 fuel oil in toluene with a concentration of 2–10 g/L. This effect depends on the concentration of dissolved substances, and the decline in membrane permeability is significantly slowed down by decreasing the fuel oil content. At low concentrations, the decrease in flux through the membranes during filtration did not exceed 18%, providing permeate fluxes of more than 286 L/(m 2 h).

Tertiary tetraols of adamantane (C10H16, Tricyclo[3.3.1.1(3,7)]decan) have been widely used for the synthesis of highly symmetric compounds with unique physical and chemical properties. The methods for one-stage simultaneously selective, deep, and cheap oxidation of adamantane to tetraols of different structures have not yet been developed. In this research, chemically simple, cheap, and environmentally friendly reagents are used and that is the first step in this direction. The conditions, under which the impact of a hydrogen peroxide water solution on adamantane dissolved in acetonitrile results in full conversion of adamantane and formation of a total 72% mixture of its tri-, tetra-, and penta-oxygenated products, predominantly poliols, have been found. Conversion and adamantane oxidation depth are shown to depend on the ratio of components of the water-acetonitrile solution and the method of oxidizer solution introduction when using the dimer form of 1:1 dimethylglyoxime and copper dichloride complex as a catalyst. Under the conditions of mass-spectrometry ionization by electrons (70 eV), fragmentation across three C–C bonds of the molecular ions framework of adamantane tertiary alcohols Ad(OH)n in the range n = 0–4 increases linearly with the rise of n.

The results of recent research on the production of aromatic hydrocarbons from biomass are summarized. Alternative types of catalytic fast pyrolysis of lignocellulosic biomass of diverse origin into bio-oil, as well as catalysts and carriers for the bio-oil hydrodeoxygenation process are reviewed. HZSM-5 zeolite is widely used as a catalyst for a biomass pyrolysis process. Oxygen-containing bio-oil compounds are converted into aromatic hydrocarbons with the best performance when noble metal-based catalysts are used, whereas acceptable performance is also achieved with molybdenum oxides and zirconium oxides. Experimental and computational data on the mechanisms of biomass components conversion to aromatic hydrocarbons are discussed.

The results of studies on the activation of С–Н and С–S bonds of thiophenes and their derivatives by transition metal compounds are summarized. A variety of thiophene-to-metal coordination modes, which depend on a particular metal and its surrounding ligands, are considered, as well as the transformations of thiophene compounds under the influence of transition metal complexes.

Information is given on the presence of diamondoids, hydrocarbons with a diamond-like structure, in oils and gas condensates. Methods for their isolation and analysis are described.

The functionalized nanocarbon materials were prepared and their structure was characterized by a set of physicochemical methods. The materials were tested as catalysts for the ethanolysis of furfuryl alcohol. The synthesis of 2-ethoxymethylfuran and ethyl levulinate in high yields was performed at 100–130°C.

Hydrocarbon resins were synthesized by thermal polymerization of the olefinic compounds of liquid pyrolysis products (the C9+ fraction, heavy tar). The hydrocarbon resins were characterized by 1H NMR spectroscopy, MALDI spectroscopy, and gel permeation chromatography. The effect of temperature, reaction time, feed composition, and solvent content on the yield, molecular weight, color, and molecular structure of the hydrocarbon resins was investigated. It was shown that addition of the C9+ fraction to heavy tar increases the polymer yield while reducing the content of aromatic fragments in its structure.

The results of studies in the area of oxidative functionalization of hydrocarbons of the adamantane series over the last two decades have been summarized and oxidation, carbonylation, and carboxylation reactions involving oxidizing agents and catalysts of various types, possible reaction mechanisms, properties and promising directions of the use of the obtained products have been considered.

Solutions of 5-vinyl-2-norbornene (VNB, 5-vinylbicyclo[2.2.1]hept-2-ene) and the related compounds 5-ethylidene-2-norbornene (ENB, 5-ethylidenbicyclo[2.2.1]hept-2-ene) and 2-vinyl-2-norbornane (VNN, 2-vinylbicyclo[2.2.1]heptane) in cyclohexane have been irradiated with γ-rays at 40°C. The initial radiation-chemical yields G 0 for the consumption of the solutes and the formation of final products of γ-radiolysis of the solvent cyclohexane have been determined. It has been shown that solute consumption and molecular hydrogen formation yields G 0(−RH) and G 0(H2), respectively, are linearly related to the first vertical ionization potential of the solute. The G 0 values of molecular hydrogen, cyclopentadiene (CPD), butadiene, and methylallene, minor products of γ-radiolysis (40°C) of liquid VNB, ENB, and dicyclopentadiene (tricyclo[5.2.1.02.6]decadiene-3.8), have been determined. It has been shown that the G 0 values of CPD formation linearly depend on the first vertical ionization potentials of γ-irradiated bicyclic dienes. It is concluded that the γ-irradiation of cyclohexane generates two kinds of radical cations, which differ in mobility and reactivity.

Glycerol alkylation with tert-butyl alcohol and ketalisation of glycerol 1-mono-tert-butyl ether with acetone, as well as the combined ketalisation-alkylation process, has been studied in a fixed-bed flow reactor. It has been shown that a continuous, one-step process for the quantitative conversion of glycerol into a mixture of ethers can be accomplished under mild conditions (atmospheric pressure and temperatures of 40-70 degrees C) over a zeolite BEA catalyst. Furthermore, the effects of the glycerol ether additives on the antiwear properties of low-viscosity base oil have been characterised. (C) 2016 Elsevier Ltd. All rights reserved.

The etherification of glycerol with n-butyl alcohol at 140°C in the presence of sulfonated cation-exchange resins and zeolite catalysts in an autoclave reactor has been studied. It has been shown that styrene—divinylbenzene ion-exchange resins are effective catalysts for the production of glycerol n-butyl ethers: the glycerol conversion is about 98% with an n-butyl ether selectivity of about 88 mol % (140°C, 5 h, 5 wt % Amberlyst 36 catalyst, and 10 wt % glycerol in n-butanol). Zeolites Y and β in the H+ form exhibit comparable specific activity (glycerol conversion of no more than 25% under similar conditions) in combination with high selectivity for glycerol di-n-butyl ethers (up to 28%).

Обобщены последние данные по получению простых эфиров, в том числе ацеталей, из возобновляемого сырья и их применению, в том числе в качестве добавок к топливам и смазочным материалам.

The catalytic dehydration of 1-butanol on γ-alumina, zeolites, and Amberlyst ion-exchange resins for the production of di-n-butyl ether (DBE) in a fixed-bed flow reactor was studied at 130–300°C and 1–70bar. The activity and selectivity of the catalysts were evaluated, and the effects of operating parameters (T, p, and VHSV) on the kinetics of the test reaction were studied for the most active catalyst samples. Based on mass balance data, a conclusion was made that zeolites and Amberlyst ion exchangers are suitable catalysts for DBE production from 1-butanol; at a feed conversion of about 70%, selectivity for DBE was 90%. These DBE yields are reported for the first time to be obtained in a fixed-bed flow reactor.