Showing papers in "Petroleum Chemistry U.s.s.r. in 1981"
TL;DR: Using cobalt and molybdenum borides as heterogeneous catalysts, the rate of liquid-phase oxidation of isobutane to tertiary hydroperoxide and tertiary butyl alcohol was increased considerably.
Abstract: Using cobalt and molybdenum borides and molybdenum carbide as heterogeneous catalysts the rate of liquid-phase oxidation of isobutane to tertiary hydroperoxide and tertiary butyl alcohol was increased considerably. It was shown that these catalysts accelerate the decomposition of tertiary butyl hydroperoxide, tertiary butyl alcohol being the main reaction product.
6 citations
TL;DR: In this paper, a study was made of skeletal isomerization of n-butenes to isobutylene at 350-425/sup 0/C and normal pressure on alumina, modified using carbon tetrachloride.
Abstract: A study was made of kinetics of skeletal isomerization of n-butenes to isobutylene at 350-425/sup 0/C and normal pressure on alumina, modified using carbon tetrachloride. A kinetic model was developed for isomerization, the process being carried out continuously, bearing in mind the variable activity of the catalyst. Calculations based on the kinetic model indicate that with a conventional contact time of 3.358 g.hr/mole stable conversion of n-butenes (33-35%) is carried out in 15 hr with the continuous use of the catalyst. Calculated results show satisfactory agreement with experimental ones.
2 citations
TL;DR: In this article, the effect of elementary sulphur, hydrogen sulphide, thiophen and diethyldisulphide additives (sulphur concentration 0·0006-0·01%) on dehydrogenation of n-dodecane containing 0·5% total sulphur was made.
Abstract: 1. 1. A study was made of the effect of elementary sulphur, hydrogen sulphide, thiophen and diethyldisulphide additives (sulphur concentration 0·0006–0·01%) on dehydrogenation of n-dodecane containing 0·0005% total sulphur, in the presence of an alumina-chromium-potassium catalysts (500°C; 0·4 MPa, space velocity 40 hr −1 , molar dilution with hydrogen 8) in experiments taking up to 6 hr. 2. 2. It was shown that thiophen already in a concentration of 0·0006% S and elementary sulphur, hydrogen sulphide and diethyldisulphide in a concentration of 0·007–0·01% S have a toxic effect on the catalyst, reducing its activity and selectivity, the toxic effect depending on the type of sulphur compound. Catalyst activity may be restored by oxidizing regeneration.
1 citations
TL;DR: In this article, a study was made of alkylation of isobutane with n-butenes in the presence of ion exchange forms of zeolites, containing ions of Ni/sup 2 +/ and rare-earth elements.
Abstract: A study was made of alkylation of isobutane with n-butenes in the presence of ion-exchange forms of zeolites, containing ions of Ni/sup 2 +/ and rare-earth elements. It was established that the addition to HCaY zeolite of Ni/sup 2 +/ ions reduces alkylate yield and increases the content of intermediate products. The use in the reaction studied of HCaY zeolite containing La/sup 3 +/ or Gd/sup 3 +/ ions increases the content of iso-octane hydrocarbons in the alkylate and reduces the content of fractions C/sub 9/ and higher.
1 citations
TL;DR: In this article, a comparison of the sensitivity of platinum and platinum-rhenium catalysts to the action of small amounts of pyridine, thiophen and carbon tetrachloride in aromatization of hydrocarbons was made.
Abstract: 1. 1. A comparison was made of the sensitivity of platinum and platinum-rhenium catalysts to the action of small amounts of pyridine, thiophen and carbon tetrachloride in aromatization of hydrocarbons. 2. 2. The action of nitride and organic halide compounds on the aromatizing activity of catalysts is contradictory to some extent; according to acid properties of catalysts and the dosage of compounds, it may be activating or deactivating in each particular case. 3. 3. The relative sulphur resistance of platinum and platinum-rhenium catalysts on contaminating with thiophen depends on hydrogen pressure. At atmospheric pressure the deactivating effect of thiophen is about the same on both catalysts and by the action of 1·1 MPa the platinum catalyst is much more sulphur-resistant than the platinum-rhenium catalyst.
1 citations
TL;DR: In this paper, it was shown that Ru/Al 2 O 3 catalysts in hydrogenation of monocyclic aromatic hydrocarbons are superior to Pd/Al O 3 in terms of activity.
Abstract: It was shown that as regards activity Ru/Al 2 O 3 catalysts in hydrogenation of monocyclic aromatic hydrocarbons are superior to Pd/Al 2 O 3 catalysts. Hydrogenation of xylenes on a Ru/Al 2 O 3 catalysts takes place mainly with the formation of cis -isomers.
1 citations
1 citations
TL;DR: In this article, the effect of previous treatment with an ammonia mixture with a small proportion of steam on catalytic properties of AShNTs-3 was made of the catalyst with a mixture of ammonia and steam at 250/sup 0/C for 2 hours.
Abstract: A study was made of the effect of previous treatment with an ammonia mixture with a small proportion of steam on catalytic properties of AShNTs-3 Preliminary treatment of the catalyst with a mixture of ammonia and steam at 250/sup 0/C for 2 hr increases considerably the yield of methylbenzylphenols, particularly 2-(cap alpha-methylbenzyl)phenol Highest yield of methylbenzylphenols is achieved at a temperature of 250/sup 0/C, a molar ratio of phenol : styrene of 4 : 1 and a space velocity of 55 hr/sup -1/
1 citations
TL;DR: In this paper, a study was made of oxidation of trimethylbenzenes to dimethylbenzoic acids in the presence of Mn and Co salts, at a temperature of 140-145/sup 0/ and with a proportion of the catalyst of (1.9-2.5) x 10/sup -4/ mole per mole raw material the conversion of the latter reaches 60-63% with a selectivity of the process of 48-75%.
Abstract: A study was made of oxidation of trimethylbenzenes to dimethylbenzoic acids in the presence of Mn and Co salts. At a temperature of 140-145/sup 0/ and with a proportion of the catalyst of (1.9-2.5) x 10/sup -4/ mole per mole raw material the conversion of the latter reaches 60-63% with a selectivity of the process of 48-75%. In selectivity of formation of dimethylbenzoic acids trimethylbenzenes are arranged in the order: 1,2,4>1,3,5>1,2,3-trimethylbenzene.
1 citations
1 citations
TL;DR: In this article, several nickel catalysts activated by elements of groups I to VII of the periodic system were synthesized and tested in steam conversion of aliphatic and aromatic hydrocarbon mixtures.
Abstract: Efficient recovery of benzene from pyrocondensates is considered to be one of the important problems of modern petroleum chemistry. In the paper presented, several nickel catalysts activated by elements of groups I to VII of the periodic system were synthesized and tested in steam conversion of aliphatic and aromatic hydrocarbon mixtures. Samples of nickel catalysts activated by W and Bi had the highest selectivity in obtaining aromatic hydrocarbons from their mixtures with aliphatic hydrocarbons. Nickel catalysts activated by V/sub 2/O/sub 3/ showed the highest activity in steam conversion of hydrocarbons of both classes. (JMT)
TL;DR: In this article, the activity of a Re/..gamma..-Al/sub 2/O/sub 3/ catalyst prepared from ammonium perrhenate in isobutane conversion with steam increases on increasing rhenium content in the catalyst.
Abstract: The activity of a Re/..gamma..-Al/sub 2/O/sub 3/ catalyst prepared from ammonium perrhenate in isobutane conversion with steam increases on increasing rhenium content in the catalyst from 1.0 to 5.0 wt.%. Further increase in rhenium content to 10.0 wt.% has no marked effect on the activity of the catalyst. A catalyst obtained from rhenic acid has the highest activity in the reaction studied.
TL;DR: In this paper, the ability of zinc dialkyldithiophosphates to inhibit initiated oxidation of ethylbenzenes depends on the structure of the hydrocarbon part of compounds.
Abstract: 1. 1. The ability of zinc dialkyldithiophosphates to inhibit initiated oxidation of ethylbenzenes depends on the structure of the hydrocarbon part of compounds. The initial period of inhibition shows a linear dependence on the constant of the electron effect of substituents at the phosphorus atom ( σ p ): with an increase in the absolute value of Σσ p the effectiveness of this type of antioxidant increases. 2. 2. Under conditions of initiated oxidation of ethylbenzene zinc dialkyldithiophosphate is used for interaction with peroxide radicals and to a greater extent for the reaction with hydroperoxides. 3. 3. The ability of zinc dialkyldithiophosphate to react with hydroperoxides under conditions of initiated oxidation may distort results of evaluating their efficiency as deactivating agents of peroxide radicals.
TL;DR: A single-stage method was developed for preparing adamantan-l-ol with a yield of 65 mole % from adamantane and tert-butyl alcohol in trifluoracetic acid (temperature 55/sup 0/; molar ratio of adamantane:tert-C/sub 4/H/sub 9/OH : TFA 1 : 2.5 : 17.
Abstract: A new single-stage method was developed for preparing adamantan-l-ol with a yield of 65 mole % from adamantane and tert-butyl alcohol in trifluoracetic acid (temperature 55/sup 0/; molar ratio of adamantane:tert-C/sub 4/H/sub 9/OH : TFA 1 : 2.5 : 17). (JMT)
TL;DR: In this paper, a study was made of decomposition of n-butylmercaptan on decationated and cation forms of zeolites, and it was shown that an increase in the acceptor function of cations increases catalyst activity.
Abstract: A study was made of decomposition of n-butylmercaptan on decationated and cation forms of zeolites. It was shown that dehydroxylation of zeolites and an increase in the acceptor function of cations increases catalyst activity. A study of this reaction on cation forms of zeolites, modified using phthalonitrile and ethylenediamine shows that on the former dehydrothiolation takes place to H/sub 2/S and C/sub 4/H/sub 8/, while on the latter--to H/sub 2/S and dibutylsulphide. (JMT)
TL;DR: In this article, the formation of acid centres with pK a greater than or equal to approx. =-10 as a result of heat-steam treatment of aluminosilicates and a reduction in the number of strong centres increases selectivity in isomerization of m-xylene.
Abstract: Conversion of m-xylene on amorphous aluminosilicates is determined by overall surface acidity. The formation of acid centres with pK a greater than or equal toapprox. =-10 as a result of heat-steam treatment of aluminosilicates and a reduction in the number of strong centres increases selectivity in isomerization of m-xylene.
TL;DR: In this paper, the authors made a study of the mechanism of formation of catalysts; a special feature of this mechanism is the interaction of components (calcium aluminates and basic carbonates of cobalt and magnesium); the carrier with a developed surface and the active component distributed on this surface are formed during this process.
Abstract: A study was made of the mechanism of formation of catalysts; a special feature of this mechanism is the interaction of components (calcium aluminates and basic carbonates of cobalt and magnesium); the carrier with a developed surface and the active component distributed on this surface are formed during this process. Catalysts show maximum selectivity in synthesis of liquid hydrocarbons from CO and H/sub 2/ with a degree of reduction of the metal of 65-84% and a dispersion (according to chemisorption of CO) of 6 x 10/sup -3/ - 10 x 10/sup -3/. Maximum yield of liquid hydrocarbons (114.1 g/nm/sup 3/) was obtained in the pressure of a system of 33Co-3MgO-64 talum treated with hydrogen at 550/sup 0/C.
TL;DR: In this article, mass-spectroscopy was used to analyze nitrogen bases isolated from crude oils of various deposits in the USSR and it was established that compounds of quinoline and acridine series represent a large part of concentrates of nitrogen bases; pyridine is contained in much smaller quantities.
Abstract: Mass-spectroscopy was used to analyze nitrogen bases isolated from crude oils of various deposits in the USSR. It was established that compounds of quinoline and acridine series represent a large part of concentrates of nitrogen bases; pyridine is contained in much smaller quantities. The overall content of nitrogen bases and their structural-group composition varies within wide limits both in oils of different deposits and in oils of the same deposit.
TL;DR: In this article, a study was made using a laboratory continuous device of oxidation of chloroprene to chloromaleic anhydride (chloromalesic acid) in a fluidized layer of a vanadium-phosphorus catalyst.
Abstract: 1. 1. A study was made using a laboratory continuous device of oxidation of chloroprene to chloromaleic anhydride (chloromaleic acid) in a fluidized layer of a vanadium-phosphorus catalyst. At the optimum temperature of 470°C, a contact time of 0·80 sec maximum chloromaleic acid yield (32·0 wt.%) is ensured; catalyst output is 203 g of chloromaleic acid/l.·cat·hr. 2. 2. A study was made of oxidation of hexachlorobutadiene to dichloromaleic anhydride on a VP catalyst. The optimum temperature was found to be 480°C, contact time 0·70 sec. Under the conditions observed process selectivity was 80 mole % with 90% conversion of hexachlorobutadiene.
TL;DR: In this paper, a comparative study was made of hydrogenating properties of industrial nickel-tungsten-sulphide catalysts 8376 (3% NiS-27% WS/sub 2/Al/Sub 2/O/sub 3/), 3076A (2NiS-WS/sub 1/40% Al/sub 0.5/O 2 ) and NVS-30 catalysts (with increased content of active structures) in a model reaction of hydrogenation of o-xylene containing 3 wt.% sulphur.
Abstract: A comparative study was made of hydrogenating properties of industrial nickel-tungsten-sulphide catalysts 8376 (3% NiS-27% WS/sub 2//Al/sub 2/O/sub 3/), 3076A (2NiS-WS/sub 2/-40% Al/sub 2/O/sub 3/), 3076 (2NiS-WS/sub 2/) and an NVS-30 catalyst (with increased content of active structures) in a model reaction of hydrogenation of o-xylene containing 3 wt.% sulphur and in the process of hydrodearomatization of a straight-run petroleum distillate and light gas-oil from catalytic cracking. It was shown that in hydrogenating activity NVS-30 catalysts are superior to most active 3076 industrial catalysts (2-1-fold) and may be used in processes of intensive hydrodearomatization of petroleum raw material without previous hydro-refining at hydrogen pressures of up to 5.0 MPa.
TL;DR: In this paper, a four-stage system was developed for preparing 2-methyl-4-alkyl-(aryl)thiacyclohexanes from α-olefins, which resulted in the formation of secondary bromides with yields higher than 90% in the absence of impurities of isomeric products.
Abstract: 1. 1. A four-stage system was developed for preparing 2-methyl-4-alkyl-(aryl)thiacyclohexanes from α-olefins. 2. 2. Methods were proposed for the hydrobromination of α-olefins, which result in the formation of secondary bromides with yields higher than 90% in the absence of impurities of isomeric products.
TL;DR: The chemical structure of polar components extracted from asphaltene-resin fractions of tar oil of Arlan crude was established in this paper, using DMFA and characterized by the presence of nitrogen and sulphur atoms in aromatic rings.
Abstract: The chemical structure was established of polar components extracted from asphaltene-resin fractions of tar oil of Arlan crude. In polar components isolated using DMFA a condensed system consisting of four to six rings and characterized by the presence of nitrogen and sulphur atoms in aromatic rings, is the most likely type of fragment.