Petroleum Chemistry (v.56, #9)
Polyolefin drag reducing agents (Review) by P. V. Ivchenko; I. E. Nifant’ev; A. V. Tavtorkin (775-787).
Main methods for the polymerization of higher α-olefins (1-hexene, 1-octene, and 1-decene) with the formation of high molecular weight products, key properties of poly-α-olefins from the viewpoint of their use as drag reducing agents in the transportation of petroleum and petroleum products, as well as the challenges and prospects of the production of these important functional materials of the petroleum industry have been considered.
Keywords: α-olefins; polyolefins; drag reducing agents
TIPS RAS GTL technology: Determination of design by S. N. Khadzhiev; M. V. Magomedova; E. G. Peresypkina (788-797).
The known hydrocarbon synthesis technologies from synthesis gas through methanol and/or dimethyl ether (DME), which were implemented in different scales plants are analyzed. Common features, advantages, and disadvantages of each technology have been noted. Several designs of TIPS RAS GTL-technology based on the original DME single-step and gasoline catalysts have been calculated and the influence of the syngas composition on the gasoline specific yield for the optimal design has been studied.
Keywords: GTL technology; gasoline synthesis; methanol; DME; synthesis gas
Polydimethylsilalkylene-dimethylsiloxanes as advanced membrane materials for thermopervaporative recovery of oxygenates from aqueous reaction media by I. L. Borisov; N. V. Ushakov; V. V. Volkov; E. Sh. Finkel’shtein (798-804).
Polydimethylsildimethylene-dimethylsiloxane (PSDMS) and polydimethylsiltrimethylenedimethylsiloxane (PSTMS) have been first studied as pervaporation membrane materials for the recovery of butanol from aqueous media. New synthesis procedures that make it possible to obtain the monomers 2,2,5,5-tetramethyl-1-oxa-2,5-disilacyclopentane (1) and 2,2,6,6-tetramethyl-1-oxa-2,6-disilacyclohexane (2) in high yields and with high purity required for subsequent polymerization have been developed. The optimum concentration of the crosslinking agent (tetraethoxysilane (TEOS)) of 5% has been found, which provides the maximum degree of crosslinking without sacrificing high values of separation factor and permeate flux. It has been shown that the permselectivity of PSDMS or PSTMS for butanol–water is higher by a factor of 1.5 or- almost 2, respectively, than the selectivity of the industrial membrane polymer, PDMS, at comparable values of the butanol permeability coefficient.
Keywords: cyclocarbosiloxanes; polydimethylsilalkylene-dimethylsiloxanes; membranes; thermopervaporation; oxygenates
An additive method for calculating the thermodynamic functions of heavy feedstock by Kh. M. Kadiev; A. M. Gyul’maliev; N. A. Kubrin (805-811).
A uniform additive method (UAM) has been developed for calculating the thermodynamic functions heat capacity C p (T), enthalpy ΔH(T), entropy ΔS(T), and Gibbs free energy ΔG(T) of both individual organic compounds with known molecular structure and heavy feedstock, using elemental analysis and 1H NMR data. The principle of the UAM is that a molecule or a unit mass of molecules of a mixture with a complex structure is represented as a unit mass of individual structural moieties (descriptors), which are transferable from one system to another. A comparison with the results of calculating the thermodynamic functions by other methods shows their satisfactory agreement, thereby giving promise that the UAM can be applied to complex systems.
Keywords: uniform additive method; thermodynamic functions; heavy petroleum feedstock; hydroconversion reactions
Influence of spectral and textural characteristics and acidity of MFI zeolite on activity of catalysts for dimethyl ether conversion to hydrocarbons by N. V. Kolesnichenko; Z. M. Bukina; L. E. Kitaev; S. A. Kurumov; E. G. Peresypkina; S. N. Khadzhiev (812-818).
Comparative data obtained by studying the synthesis of С5+ hydrocarbons from dimethyl ether (DME) on catalysts using MFI zeolites available from different manufacturers are presented. It has been shown that MFI zeolite samples substantially differ in their acidic properties and structural, morphological, and textural characteristics. The catalysts based on different MFI zeolites also noticeable differ in the yield and chemical composition of С5+ hydrocarbons. By switching from the stand-alone operation of a DME conversion reactor to the joint operation of two reactors for synthesis of oxygenates (DME and/or methanol) from synthesis gas and synthesis of hydrocarbons from oxygenates connected by a single circuit, high selectivity for hydrocarbons of the gasoline fraction is achieved with the catalyst based on the MFI zeolite, for which the bands characteristic of Н3О+ acid sites are observed in diffuse reflectance IR spectra.
Keywords: zeolite; dimethyl ether; adsorption; desorption; synthesis gas; oxygenates; gasoline fraction; zeolite catalyst
Effect of the degree of zeolite recrystallization into micro–mesoporous materials on their catalytic properties in petroleum refining and petroleum chemistry processes by O. A. Ponomareva; I. A. Kasyanov; E. E. Knyazeva; S. V. Konnov; I. I. Ivanova (819-826).
It has been shown that by varying the degree of recrystallization of zeolites, it is possible to obtain mesostructured zeolites (RZEO-1), micro–mesoporous nanocomposites (RZEO-2), and mesoporous materials with zeolite fragments (RZEO-3). The main features of the effect of recrystallization degree of MOR, BEA, and FER zeolites on their catalytic properties in the processes of cracking of 1,3,5-triisopropylbenzene, skeletal isomerization of butene-1, hydroisomerization of n-alkanes, alkylation of benzene with dodecene-1, alkylation of naphthalene with cyclohexene, and disproportionation of cumene have been revealed. It has been found that each type of catalytic reaction requires a micro–mesoporous catalyst with an optimal degree of recrystallization. Zeolites RZEO-1 are the most efficient in the reactions that require strong acidity; zeolites RZEO-2 are the most promising in consecutive reactions and reactions that proceed in pore mouths; and RZEO-3 are optimal for transformations of bulky molecules.
Keywords: zeolite; recrystallization; micro–mesoporous materials; hierarchical zeolites; catalysis; petroleum chemistry; petroleum refining
Formation of MFI-type zeolite nanoparticles and zeolite-based suspensions by N. V. Kolesnichenko; N. N. Ezhova; O. V. Yashina (827-831).
Based on a commercial zeolite of the MFI type, nanoparticles have been produced using mechanical methods (grinding in a ball or planetary mill, classification by “stirring-up”) and ultrasonic treatment (UST) of zeolite in water. It has been found by spectral methods (XRD, DRIRS, 27Al and 29Si solid-state NMR) and adsorption analysis that the grinding of the zeolite leads to partial degradation of its structure and appearance of defects in the crystalline framework, whereas the zeolite crystal lattice remains completely intact after sonication in the aqueous medium. The sonication destroys MFI agglomerates to form nanoparticles down to 40–50 nm in size. The dispersion of the zeolite nanoparticles in silicone or hydrocarbon oil–(Syltherm 800 or Dowtherm RP, respectively) as a high-boiling-point liquid leads to the formation of ultrafine suspensions, the stability of which depends on the type of the dispersion medium. The nanosized zeolite suspensions are more stable in Dowtherm RP than in Syltherm 800: without agitation, they are persistent for at least 3 weeks (settling at room temperature).
Keywords: catalysis in dispersed phase; catalysis on zeolites; nanosized zeolites; zeolite nanoparticles; conversion of dimethyl ether; lower olefins
Oxidative pyrolysis of propane with an admixture of ethylene by N. M. Pogosyan; M. D. Pogosyan; S. D. Arsentiev; L. N. Strekova; L. A. Tavadyan; V. S. Arutyunov (832-835).
It has been shown that in the case of noncatalytic oxidative pyrolysis of propane, the admixture of ethylene in the reactants significantly increases the concentration of propylene in the products. This process can be arranged in such a manner that the ethylene will not be noticeably consumed, i.e., will actually act as a propylene formation catalyst. This arrangement opens up a possibility to design a selective process for producing propylene directly from propane.
Keywords: propane; oxidative pyrolysis; propylene; ethylene
Conversion of triglycerides to fuel hydrocarbons over a Pt–Pd–Al–HMS catalyst by A. B. Kulikov; M. I. Onishchenko; I. A. Sizova; A. L. Maksimov; S. V. Lysenko; E. A. Karakhanov (836-840).
The hydroconversion of rapeseed oil fatty acid triglycerides (TGs) over a mesoporous platinum–palladium aluminosilicate catalyst has been studied. It has been shown that, in a temperature range of 250–375°C at a hydrogen pressure of 60 atm, the TGs undergo complete deoxygenation and the resulting products undergo isomerization. Under optimum process conditions, the diesel fraction yield is 94%. The resulting fraction can be used as an environmentally safe fuel component.
Keywords: triglycerides; plant raw materials; hydrodeoxygenation; hydroisomerization; mesoporous aluminosilicates; bimetallic catalyst; diesel fuel
Oxidative conversion of ethane involving lattice oxygen of molybdenum systems modified with aluminum, gallium, or yttrium oxide by N. Ya. Usachev; I. M. Gerzeliev; V. V. Kharlamov; V. P. Kalinin; E. P. Belanova; S. A. Kanaev; A. V. Kazakov; T. S. Starostina (841-845).
Oxidative conversion of ethane on the molybdenum oxide MoO3 mixed with 0–95% Al2O3, Ga2O3, or Y2O3 has been studied in the pulse mode at 600°C. It has been revealed that the components of these systems undergo strong interaction, which leads to enhanced ethane conversion and an increased selectivity for ethylene with a decrease in the MoO3 content. The 5%MoO3–95%Al2O3 system has proved the most effective in the oxidative dehydrogenation of ethane, with the selectivity for ethylene reaching 90% at an ethane conversion of 30 wt %.
Keywords: ethane; ethylene; oxidative dehydrogenation; oxides; molybdenum; aluminum; gallium; yttrium
Thermal and structural properties of molybdenum systems modified with aluminum, gallium, or yttrium oxide by N. Ya. Usachev; I. M. Gerzeliev; E. P. Belanova; A. V. Kazakov; V. P. Kalinin; V. V. Kharlamov; S. A. Kanaev; T. S. Starostina (846-851).
Oxide systems prepared by thermal decomposition of mixtures of ammonium heptamolybdate with varying amounts of aluminum, gallium, and yttrium nitrates have been studied by thermal analysis, X-ray powder diffraction, and scanning electron microscopy. The formation processes, the nature of interaction between the components, and the states of these systems have been determined. It was shown that the nature of oxides in the molybdenum systems have a significant effect on their physicochemical properties.
Keywords: oxides; molybdenum; aluminum; gallium; yttrium; TG-DTA; XRD; SEM
Ethylene carbonate production by cyclocondensation of ethylene glycol and urea in the presence of metal oxides and metal acetylacetonates by A. S. Lyadov; A. A. Kochubeev; E. B. Markova; S. N. Khadzhiev (852-856).
A promising method for the production of ethylene carbonate is the cyclocondensation of ethylene glycol and urea in the presence of a catalyst. In this study, the catalytic effect of oxides and acetylacetonates of various metals on the occurrence of this reaction has been examined. It has been shown that cobalt acetylacetonate is the most effective catalyst. The effect of reaction conditions (temperature, pressure, contact time, and catalyst concentration) on the main parameters of catalytic conversion has been studied.
Keywords: ethylene carbonate; ethylene glycol; urea; metal oxides; metal acetylacetonates
Dimethyl ether in the processing of associated petroleum gas to a mixture of synthetic hydrocarbons by N. A. Markova; Z. M. Bukina; D. A. Ionin; N. V. Kolesnichenko; S. N. Khadzhiev (857-862).
The development of single-stage synthesis of dimethyl ether (DME) from synthesis gas makes it possible to obtain hydrocarbons directly from DME. The effect of the nature and concentration of components of the vapor–gas mixture that arrives at the stage of DME conversion to liquid hydrocarbons on activity and selectivity of a zinc–palladium zeolite catalyst has been examined. It has been found that and increase in DME concentration to more than 20 vol % in the reaction stream leads to lowering both DME conversion and gasoline selectivity and increasing the yield of byproducts. The presence of components such as H2, CO, H2O in the vapor–gas mixture ensures high stability of the catalytic system. Switching from the flow-through to the recycle operation mode increases the catalyst selectivity for gasoline, decreases the formation of durene, and reduces catalyst coking.
Keywords: associated gas; synthesis gas; dimethyl ether; oxygenate; synthetic hydrocarbons; light gas condensate; zeolite catalyst
The role of interstage separation of reformate in improving the efficiency of a fixed-bed catalytic reforming process by D. O. Kondrashov (863-868).
The results of the development of technology for interstage separation of reformate in the reforming process with a fixed-bed catalyst are discussed. It has been shown that the proposed isolation of the 150°C–FBP fraction from the feedstock can significantly increase the yield of aromatic hydrocarbons, to improve the selectivity of the process, to increase the reformate yield (by 6–8 wt % on a feed basis), and to lower the charge of an expensive platinum catalyst in a reactor to 20%.
Keywords: catalytic reforming; stepwise reforming; interstage separation of reformate; enhancement of reformate yield
Plasma-induced decomposition of heavy hydrocarbons by G. R. Ganieva; B. A. Timerkaev (869-872).
A method has been proposed for decomposition of heavy hydrocarbons into light fractions in arc plasma with rotating electrodes immersed in the hydrocarbon feedstock. Chromatographic analysis of the product gases has been performed, and the carbonaceous deposits formed on the electrodes during the experiment have been studied using electron microscopy and infrared spectroscopy.
Keywords: heavy hydrocarbons; fuel oil; arc discharge; plasma chemistry; decomposition of hydrocarbons; carbon nanotubes
Diesters of adamantanecarboxylic acids as promising components of base stocks for industrial synthetic oils by E. A. Ivleva; M. R. Baimuratov; Yu. A. Zhuravleva; Yu. A. Malinovskaya; Yu. N. Klimochkin; I. A. Kulikova; V. V. Pozdnyakov; N. A. Sheikina; V. A. Tyshchenko (873-875).
Viscosity–temperature properties and thermo-oxidative stability of polyoxyalkylene polyol and hydrogenated polyalphaolefin base stocks before and after introducing diesters of sebacic or 5,7-dimethyl-3-carboxy-1-adamantylacetic acids have been studied using high-pressure differential scanning calorimetry (PDSC) according to ASTM E2009. The potential for the use of diesters of the adamantane series as a component of a base stock for industrial synthetic oils instead of sebacic acid diester has been demonstrated.
Keywords: adamantane; esters; thermo-oxidative stability; base stock; lubricants
Comparison of structural-group compositions and properties of base oils obtained in solvent refining and hydrotreating processes by N. N. Tomina; S. A. Antonov; N. M. Maksimov; A. A. Pimerzin; A. A. Roganov; M. V. Babintseva; I. I. Zanozina (876-878).
The structural-group composition and properties of the base oil samples obtained by solvent extraction technology and with the use of hydrofinishing of the solvent refined product have been studied. Sample 1 has been obtained via solvent refining and subsequent dewaxing, and samples 2 and 3 have been obtained according to a scheme comprising solvent refining and raffinate hydrofinishing over a NiMoW/ZnO-Al2O3 catalyst followed by dewaxing. The hydrotreating of the raffinate in the presence of the modified NiMoW/ZnO-Al2O3 catalyst can be conducted under mild conditions at 5.0 MPa.
Keywords: lube oil distillate; structural-group composition; dewaxing; raffinate hydrotreating; paraffinic–naphthenic hydrocarbons
Antiwear and extreme pressure properties of N-substituted dithiazacycloalkanes in mineral oils by G. R. Khabibullina; V. R. Akhmetova; E. S. Fedotova; V. R. Nigmatullin; R. G. Nigmatullin; A. G. Ibragimov (879-882).
Antiwear and extreme pressure properties of N-substituted 1,3,5-dithiazinane and 1,5,3-dithiazepanes obtained via the cyclothiomethylation of amines (monoethanolamine, propylamine) with formaldehyde and SH acids (H2S, 1,2-ethanedithiol), taken in an amount of 3 wt %, in mineral oils have been studied.
Keywords: lubricating oil additives; extreme pressure properties; dithiazacycloalkanes
Hydrofining of vegetable, synthetic, and petroleum blendstocks to produce diesel fuel by L. A. Gulyaeva; O. I. Shmel’kova; V. A. Khavkin; O. M. Mis’ko; R. E. Boldushevskii (883-887).
The process of co-hydrofining of pyrolysis products and Fischer–Tropsch synthetic crude with petroleum diesel distillate at a pressure of 5–8 MPa and 330–370°C in the presence of a conventional CoMo–Al2O3 hydrotreating catalyst has been studied, and the trends in the behavior of the physicochemical characteristics of the resulting products have been revealed. The feasibility of manufacturing class K5 diesel fuel containing the alternative components in amounts of 20 and 30 vol % by involving the pyrolysis products and synthetic crude, respectively, in the process has been demonstrated.
Keywords: wood biomass; liquid pyrolysis product; synthetic crude; petroleum diesel distillate; hydrofining; hydrodeoxygenation; diesel fuel component