Petroleum Chemistry (v.49, #5)
Kinetic parameters and geometry of the transition state in the unimolecular degradation of alcohols by T. S. Pokidova; E. T. Denisov; A. F. Shestakov (343-353).
Experimental data on the unimolecular degradation of structurally different alcohols, alkanols into water and an olefin and alkenols into a carbonyl compound and an olefin, were analyzed in terms of the method of crossing parabolas. The kinetic parameters characterizing such decomposition were calculated and factors that affect the activation energy of the reaction (the cycle strain energy, the steric factor, and the effect of π electrons neighboring the reaction center) were determined. The activation energies and the rate constants were calculated for 30 alcohol degradation reactions. The enthalpies, the activation energies, and the rate constants of degradation of unsaturated alcohols were compared for two different degradation routes yielding a carbonyl compound and an olefin or resulting in water and an olefin. Quantum-chemical calculations of the transition states for three model reactions were performed. The activation energies and the rate constants were obtained for the first time for 13 reverse reactions of the addition of carbonyl compounds to olefins.
Distribution of low-molecular-mass nitrogen compounds in crude oils and organic matter of Upper Jurassic rocks of Western Siberia by S. S. Yanovskaya; T. A. Sagachenko (354-359).
The distribution of low-molecular-mass nitrogen-containing components of oils and dispersed organic matter in the Upper Jurassic play of Western Siberia has been studied. It has been found that their amount in the organic matter of rocks is higher than that of corresponding oils. In all test samples, low-molecular-mass nitrogen compounds are represented by a mixture of strong and weak bases. The qualitative composition of these compounds is the same. The nitrogen bases of the dispersed organic matter differ from petroleum bases by an increased amount of weakly basic components and structures with unhindered nitrogen atoms.
Selective hydrogenation on palladium-containing catalysts of byproduct phenylacetylene present in industrial fractions of styrene by R. A. Basimova; M. L. Pavlov; S. I. Myachin; A. V. Prokopenko; A. V. Askarova; B. I. Kutepov; S. A. Sychkova (360-365).
The process of liquid-phase hydrogenation of the phenylacetylene byproduct in the industrial styrene fractions formed in different styrene manufacture stages at OAO Salavatnefteorgsintez was studied on specimens of the palladium-containing G-58E, APKGS-20E2, and KSVK catalysts. It was found that the KVSK catalyst, which is a silica glass-fiber matrix containing 0.2 wt % of dispersed palladium, was the most effective in the selective hydrogenation at atmospheric pressure and temperatures of 20–30°C of phenylacetylene present in the industrial fractions of styrene. It was shown that the minimal loss of styrene is attained in the case of phenylacetylene hydrogenation in the hydrocarbon condensate fraction.
Catalytic hydrogenation of dicyclopentadiene to dicyclopentene in the liquid phase by T. N. Antonova; I. A. Abramov; V. Sh. Feldblyum; I. G. Abramov; A. S. Danilova (366-368).
A new use for dicyclopentadiene has been proposed in the area of preparation of oxygen-containing compounds, including those with a cage structure, the key stage of which is the selective liquid-phase hydrogenation of dicyclopentadiene to dicyclopentene with hydrogen over finely divided hydrogenation catalysts based on platinum group metals. The process proceeds under mild conditions at atmospheric pressure. Conditions providing a yield of 92% for the desired product with an almost complete conversion of the reactant dicyclopentadiene have been determined in the study of the hydrogenation reaction in both a volumetric device of the closed type and a continuous-flow system.
Catalytic transformations of mono- and bis-silyl substituted norbornadienes by M. L. Gringolts; M. V. Bermeshev; Yu. V. Nelyubina; E. Sh. Finkelshtein (369-376).
Transformations of 2-trimethylsilylnorbornadiene-2,5 (SNBD) and 2,3-bis(trimethylsilyl)norbornadiene-2,5 (DSNBD) under metathesis and addition polymerization conditions were studied. In the presence of the WCl6/1,1,3,3-tetramethyldisilacyclobutane-1,3 and Cl2(PCy3)2Ru=CHPh catalysts, high-molecular-mass silicon-substituted poly(cyclopentylidene vinylene)s were obtained with yields up to 98%. Under addition polymerization conditions, SNBD and DSNBD dimerized on the nickel(II) naphthenate-methyl alumoxane catalyst to give pentacyclic dimers. Three dimers were detected in the case of SNBD, whereas the exo-trans-exo-cyclodimer alone was exclusively produced from DSNBD. Being inactive in addition homopolymerization, both SNBD and DSBND take part in addition copolymerization with norbornene.
Catalytic arylation and alkylation of phenol with components of the 130–170°C fraction of pyrolysis products by Ch. K. Rasulov; A. G. Azizov; V. G. Mirzoev; R. K. Azimova; S. I. Abasov; S. Z. Alieva (377-380).
The results of phenol aralkylation with components of the 130–170°C fraction of pyrolysis products on zeolite impregnated with orthophosphoric acid in a flow reactor are presented. The optimal conditions of p-aralkylphenol synthesis have been found. Under the optimal conditions, the yield of the desired aralkylphenol was 53.6% of the theoretical value and the selectivity was 95.5%. A p-aralkylphenolamine resin was synthesized on the basis of p-aralkylphenol and hexamethylenetetramine and was tested as an antioxidant for M-8 motor oil at high temperatures.
Alkylation of diols under phase transfer conditions: The influence of the nature of the substrate, alkylating agent, and organic solvent by N. V. Morozova; N. N. Lebedeva; L. P. Panicheva (381-384).
The alkylation of ethanediol and butanediol-1,4 with allyl chloride in a two-phase system composed of an organic phase and an aqueous alkali solution was studied. It was shown that the phase transfer agent not only ensures the phase transfer effect, but also affects the reactivity of the diols. Butanediol-1,4 was alkylated with various alkylating agents. An optimal solvent for O-alkylation under the phase transfer catalysis conditions was found.
Effect of zinc-subgroup metal salts on the formation of hydroperoxide during the oxidation of cumene by N. M. Nurullina; N. N. Batyrshin; Kh. E. Kharlampidi (385-388).
The oxidation of cumene catalyzed by zinc, cadmium, and mercury 2-ethylhexanoates was studied. It was found that the catalytic effect weakens in the order Cd-Hg-Zn. The influence of an initiator on the cumene hydroperoxide buildup in the presence of group IIB metal compounds was revealed.
The Role of N-hydroxyphthalimide in the oxidation reactions of alkylarenes with molecular oxygen by I. A. Opeida; M. A. Kompanets; O. V. Kushch; E. G. Yastrebova (389-392).
The kinetics of the liquid-phase oxidation of alkylarenes with molecular oxygen in the presence of the initiators azobisisobutyronitrile and benzoyl peroxide and the catalyst N-hydroxyphthalimide (NHPI) was studied. It was found that the rate of oxidation of alkylarenes depended on the partial pressure of oxygen, an effect that is explained by its involvement in the reaction with NHPI resulting in the initiation of the oxidation chain.
Specifics of oxidation of octene-1 with molecular oxygen on vanadium disilicide by Yu. B. Trach; O. I. Makota (393-396).
The catalytic properties of metal disilicides TiSi2, VSi2, MoSi2, HfSi2, TaSi2, and WSi2 in the reaction of liquid-phase oxidation of octene-1 with molecular oxygen and the kinetic features of this process in the presence of the most active disilicide VSi2 were studied. It was shown that the disilicides had an effect on the oxidation process only in the presence of hydroperoxide. It was found that the rate of oxidation on VSi2 increased owing the enhancement of the radical generation reaction via the bimolecular degradation of the hydroperoxide. A kinetic scheme was proposed which adequately describes the process, and the kinetic parameters of the process were calculated.
Study of 4-acetylaminotoluene ozonation in acetic acid by A. G. Galstyan; A. S. Bushuev; Yu. A. Shumilova (397-400).
The reaction of 4-aminotoluene with ozone in acetic acid was studied. It was found that the reaction proceeds at a high rate, giving predominantly tars. The product composition changes after acylation of the amino group: aliphatic peroxides prevailed among the oxidation products and 4-acetylaminobenzoic acid was identified (16%) as well. It was shown that the presence of a catalyst (cobalt(II) acetate) had no substantial effect on the oxidation selectivity for the methyl group (32%) and only the addition of potassium bromide increased the activity of the catalyst; the yield of 4-acetylaminobenzoic acid reached 70%. The mechanism of oxidation in the presence of a cobalt-bromide catalyst explaining the obtained results was discussed.
Use of thin-layer chromatography with closed sorption layer for the determination of volatile compound by V. G. Berezkin; I. I. Ashrapova; A. V. Chausov; A. S. Lermontov; V. F. Tret’yakov; E. V. Egorova; S. A. Leont’eva (401-405).
For decades, it has been believed in Russian and foreign scientific and technical literature that conventional thin-layer chromatography (TLC) cannot be used for the determination of volatile compounds. Experiments have shown that the version of TLC with a closed adsorbent layer proposed recently at the Topchiev Institute, Russian Academy of Sciences, is applicable to the investigation of the group content of aromatic hydrocarbons in gasoline. It has been found that the best resolution of analyte groups of compounds can be achieved by means of circular chromatography and sample introduction into a chromatographic system, using the frontal variant of chromatography.
Adsorption treatment of pyrolysis gasoline for the removal of resins and sulfur compounds by V. N. Sharifullin; A. V. Sharifullin; Yu. N. Zhiryakov (406-409).
It was found that the equilibrium isotherms of the adsorption of sulfur compounds and resins by activated carbon from pyrolysis gasoline have an unusual, S-shaped profile. It is this character that has been proven to be responsible for the unfeasibility of pyrolysis gasoline cleaning of resins and sulfur compounds to a high degree (>80%). The kinetics of the process was studied, and the experimental data were processed with the external mass transfer kinetic equation.
The synthesis and physicochemical parameters of new nonionic surfactants based on 1,2-propylene glycol, epichlorohydrin, and orthophosphoric acid by G. A. Ahmedova (410-414).
1,2-Propylene glycol has been chloroxypropylated with epichlorohydrin. The structures and compositions of synthesized oligomers having different average degrees of chloroxypropylation have been determined by IR and 1H NMR spectroscopy. The physicochemical parameters of the oligomers have been determined, and their surface activity has been studied. The same characteristics have been found for 1,2-propylene glycol chloroxypropylates phosphatized with H3PO4. The ability of these products to retard the evaporation of gasoline during storage has been revealed.
The synthesis of adipic acid from caprolactam-containing waste by Yu. A. Druzhinina; I. L. Glazko; S. V. Levanova (415-419).
An efficient method for the synthesis of adipic acid from caprolactam-containing waste has been developed. The kinetic characteristics of the process have been studied and the optimum conditions of the synthesis have been found.
The features of the catalytic synthesis of methanethiol from dimethyl sulfide by A. V. Mashkina (420-426).
The characteristic features of methanethiol synthesis from dimethyl sulfide and H2S in the presence of Al2O3 at atmospheric pressure and T = 320–500°C have been studied. It has been shown that the yield of methanethiol increases with an increase in the temperature, the H2S-to-dimethyl sulfide ratio, and the contact time, attaining equilibrium values. The methanethiol formation rate is proportional to the dimethyl sulfide partial pressure raised to a power of 0.4 and the H2S partial pressure raised to a power of 0.8. An increase in the specific surface area and the volume of transport pores and a decrease in the particle sizes of Al2O3 facilitate the augmentation of the catalyst activity in methanethiol formation. At T ∼ 400°C, a low H2S concentration, and a long contact time, the side reaction of dimethyl sulfide cracking occurs to result in the release of methane and the deposition of sulfur-containing and carbonaceous compounds on the surface, which lower the activity of alumina. The deactivated catalyst can be regenerated by oxidation.
The synthesis of some 3-thietanyl-substituted thiocarbamides and the study of their antioxidant activity by R. Yu. Akhmedov; I. A. Rzaeva; V. M. Farzaliev; M. A. Allakhverdiev (427-431).
3-Thietanyl-substituted thiocarbamides were synthesized via the reaction of 3-thietanyl-substituted isothiocyanate. The synthesized compounds were found to exhibit a high antioxidant activity in the inhibited oxidation of cumene.
The synthesis of alkane dinitrates and theirs efficiency for cetane improver by Songsom Siraprapakit; Polkit Sangvanich; Preecha Lertpratchya; Somchai Pengprecha (432-435).
Dinitrate compounds was prepared from alkane diols; 1,6-hexane diol, 1,8-octane diol, 1,10-decane diol, and 2-methyl-2,4-pentane diol using nitration reaction. These dinitrate compounds were used as cetane improver for diesel fuel. Results showed that the cetane number values has increased about 1 and 3 units for 0.05 and 0.10% by weight of dinitrate compounds, respectively, compared with base oil. Their efficiency is higher than commercial cetane improver, 2-ethylhexyl nitrate.
Effect of various sono-oxidation parameters on the desulfurization of diesel oil by Yongchuan Dai; Yutai Qi; Dezbi Zhao (436-441).
The influences of ultrasonic intensity, H2O2 concentration, ratio of H2O2 to oil and the addition of Fenton reagent on the oxidative desulfurization of diesel oil under ultrasonic irradiation were investigated. It was observed that the oxidative desulfurization of diesel oil fitted pseudo-first-order kinetics under our experimental conditions. Increasing the ultrasonic intensity increased the oxidative desulfurization efficiency of diesel oil. The addition of H2O2 enhanced the ultrasonic oxidative desulfurization efficiency of diesel oil. The sono-oxidation treatment in combination with Fenton reagent showed a synergistic effect for diesel oil desulfurization. The catalytic oxidative desulfurization process under ultrasonic irradiation process on diesel oils is an efficient and promising method.