Vol 59, No 6 (2019)

In this work, a spiro diborate (SDB), different from the traditional polymers, was synthesized from glycerol monolaurate and boric acid, and was evaluated as viscosity-reducer and pour point depressor for crude oil. The evaluation showed that this spiro compound can improve the flow properties of crude oil samples by reducing the viscosity of crude oil by 82.3% at most and depressing the pour point by 8.0°C. The role of SDB in limiting the degree of cocrystallization can be further confirmed by the average particle size and the particle morphology analysis of saturated hydrocarbons (HC) component illustrated from microscopic crystal morphology. So it can be concluded that the high content of saturated HC makes for the effective viscosity reduction.

It has been found as a result of the investigation of the catalytic properties of various microporous zeolites (of FAU, BEA, MOR, and MFI structural types) and a micro–meso–macroporous H-Ymmm zeolite (FAU) in the alkylation reaction of arenes (benzene (II) and toluene (III)) with the unsaturated compound 2-methyl-2-vinyl-gem-dichlorocyclopropane (I) that the reaction proceeds with the formation of chloroalkylarenes [1-(2,2-dichloro-1-methylcyclopropyl)ethyl]benzene (IV) and 1-[1-(2,2-dichloro-1-methylcyclopropyl)ethyl]-4-methylbenzene(V). Compounds IV and V are the most selectively formed over H-Beta (up to 82%) and H-Ymmm (up to 79%) zeolite catalysts with a high conversion of I (from 90% to full). It has been shown that high selectivity for chloroalkylarenes IV and V is achieved at 100°C, an arene : unsaturated compound molar ratio of 8 : 1, a catalyst concentration of 20 wt % of the reaction mass, and a reaction time of 2 h.

The catalytic activity of zeolites of three types—Y, ZSM-5, and Beta—in the cracking of С₂₀–С₃₅n-alkanes in a three-phase reactor has been studied under the following conditions: a temperature of 300–380°C, a hydrogen pressure of 7 atm, and a catalyst content of 1 wt %. It has been shown that the activity of zeolite Beta in cracking reactions is several times higher than the activity of zeolites of the other types. This finding can be apparently attributed to a large mesopore volume in the Beta structure.

The possibility that a process comprising the oxidation of sulfur compounds present in gas condensate and its subsequent rectification can be used to desulfurize light petroleum fractions has been explored. Oxidation of gas condensate with hydrogen peroxide in the presence of transition metal salts followed by its rectification makes it possible to decrease the sulfur content in the gasoline and diesel fractions by 95 and 75%, respectively in the fraction, with the sulfur content of -the residual fraction (350°C–FBP) remaining almost unchanged.

The effect of active component content on the catalytic activity of supported sulfide catalysts in the synthesis of C₁₇ olefins from stearic acid has been studied. It has been shown that an increase in the nickel content leads to a decrease in the catalyst activity; in addition, there is a negative correlation between the activity and the fraction of large particles on the support surface. The highest heptadecene selectivity (50–60%) is observed for alumina-supported catalysts owing to the higher degree of dispersion of the active component.

The conformations of molecules in a diene (butadiene, isoprene) complex with hydrogen peroxide and isopropyl alcohol, for which local energy minima are identified, and a mechanism of hydrogen peroxide decomposition have been studied by the quantum-chemical density functional theory method. It has been shown that depending on the initial multiplicity of the system, the decomposition can result in the formation of different intermediate and final products, which indicates the probability of singlet to triplet conversion of hydrogen peroxide in the real system.

The interaction of 2-monosubstituted 1,3-dioxolanes with 3-hexyl-1-ethylaluminacyclopentane leads to the cleavage of the Al–C bond of the metallocycle and the formation of ethylene glycol monoethers after hydrolysis of the resulting reaction mixture. Catalytic amounts of ZrCl₄ or Ni(acac)₂ activate the process. The reaction of 2-monosubstituted 1,3-dioxolanes with 1-ethyl-3-naphthylaluminacyclopentane yields the product of cleavage of the exocyclic Al–Et bond of aluminacyclopentane.