Том 57, № 3 (2017)

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.

The structural and rheological properties of resin-free model petroleum mixtures (MPM) with an asphaltene content of 0 to 6 wt % and the same mixtures with added 3.85 wt % petroleum resins have been investigated. The composition of the mixtures simulates the amount of the main hydrocarbon-group components and distillate fractions in light paraffin-base oils (ρ₄²⁰ = 747.7–789.1 kg/m³). Temperature–dynamic viscosity relationships for cooling the MPM have been obtained, most of which displayed abnormalities in the temperature range of ~40–60°C. Calculations of the viscous-flow activation energy (E_μ) have shown that there are abrupt changes in E_μ in this abnormality region, which are an indication of structuring processes. By means of Fourier-transform laser diffractomery of MPM solutions in kerosene, it has been found that the particle size of the petroleum mixtures is qualitatively related to the revealed abrupt changes in E_μ. It has been shown that these abnormalities correspond to the formation of paraffin–asphaltene associates and their existence is determined by the critical concentration of resins and asphaltenes in the mixtures.

The effect of temperature (530–590°C), weight hourly space velocity (2.5–7.0 h^–1), and the Si/Al ratio of the ZSM-5 zeolite (30, 55, 80, 300) on the cracking of a butane–butylene fraction containing 85 wt % butylenes has been studied. The HZSM-5 zeolite has been modified with phosphorus. The effect of modification on the catalyst activity in cracking reactions has been studied. The ethylene and propylene yield achieves 38.4 wt % at a degree of conversion of butylenes of 81.5%. The ethylene to propylene ratio is 0.55.

Highly thermoconductive, active and selective catalysts based on commercial nickel foam for partial oxidation and dry reforming of methane have been designed. The developed catalysts have been synthesized by subjecting the nickel foam to electrochemical treatment providing the formation of nickel, molybdenum, tungsten, or cobalt oxide or hydroxide particles on the surface of the material. The catalysts provide the production of synthesis gas with a nearly 100% selectivity and a methane conversion of up to 98–100%.

The effect of the nature of a chromium(III) coordination compound and various substituted pyrrole ligands on ethylene oligomerization in the presence of a Cr(III) complex–pyrrole ligand (L)/AlEt₃ catalyst system (CS), where Cr(III) is Cr(EH)₃, Cr(асас)₃, or CrCl₃(THF)₃ and L is pyrrole, 2-phenylpyrrole, 2-formylpyrrole, N-methylpyrrole, or N-vinyl-2-phenylpyrrole, has been studied. It has been shown that the most significant effect on the behavior of the CS is exerted by the nature of the ligand involved in the formation of the CS. The acid–base properties of the employed ligands have been determined by quantum-chemical calculations. The data obtained have revealed that selectivity of the catalyst system depends on the ligand basicity.

It has been found that process time and temperature affect the isomer ratio of alkylphenols depending on the catalyst type. Phenol alkylation with linear α-olefins leads a prevalence of ortho-alkylphenols over the para-isomers, unlike the case of branched olefins.

Experimental data on frequency–temperature relationships tanδ(t, f) for diesel fuel (DF) and the diesel containing the pour-point depressant Dodiflow-4971 (DDF) and C₁₀–C₁₈ higher fatty alcohols (HFA) are presented. The tanδ (t, f) relationships have been obtained in the frequency range of f = 0.025–1000 kHz at temperatures (t) ranging from −40 to +100°C. For the diesel and the DF + DDF, DF + HFA, and DF + DDF + HFA systems, two temperature regions of dispersion of tan δ have been revealed, the high-temperature region from 60 to 8°C and the low-temperature region from 19 to −40°C. Based on the ratio of dielectric loss tangent in the interval of the colloidally dispersed state of the diesel doped with additives (Adi) to that of the additive-free diesel fuel, \({\text{tan}}{\delta _{{\text{DF}}}}_{{\text{ + A}}{{\text{d}}_i}}{\text{/ tan}}{\delta _{{\text{DF}}}}\) , an indicator of additive dewaxing performance (IADP) has been proposed, which makes it possible to predict the performance of the additives as activators of the diesel dewaxing process in an electric field.

Partial and complete dichlorocarbenation of conjugated diene hydrocarbons in the presence of the phase-transfer catalyst catamine AB has been studied. It has been shown that at the initial stages of the process (conversion of the reactant olefins below 30%), alkenyl-gem-dichlorocyclopropanes are the main products. In the case of complete carbenation, corresponding bicyclic structures are formed. The structures of the resulting stereoisomers have been described in detail using ¹H and ¹³С NMR methods. The relative reactivity of the initial dienes has been determined using a method of competitive kinetics.

Several methods had been used to minimize the problems caused by wax deposition in crude oil pipelines during the production and transportation of waxy crude oil; among them, the continuous addition of wax inhibitor (Abbreviation for WI) is considered as the most efficient one. This study uses two kinds of polymeric compounds as wax inhibitors with different solvents on the pour point and viscosity of mixed waxy oils evaluated. These four wax inhibitors defined as WI-1, WI-2, WI-3, WI-4, respectively. Five types of mixed waxy oil have the same wax content but different resin contents. Meanwhile, different resin contents affect the pour point and viscosity of mixed oils. Under different processing temperature, the viscosity of mixed oil measured when the temperature changes among 20 to 60°С. In this work, the results were that the effect of WI-1 and WI-3 relied on the resin content, processing temperature and dosing concentration. For mixed waxy oils, the pour point reductions contacted with dosing concentration and the resin content. The wax inhibitor shows good efficiency when the resin content was between 1.01 and 4.03 wt %. When the WI-1 added, the pour point of mixed oil-1 reduced 30°С at most and viscosity of mixed waxy oil greatly reduced. In sum, toluene as solvent shows better performance of wax inhibitors.