E. V. Rakhmanov

Oxidative desulfurization of diesel fraction with hydrogen peroxide in the presence of catalysts based on transition metals

The oxidative desulfurization of a straight-run, nonhydrotreated diesel fraction (boiling range 178–342°C) containing benzothiophene, dibenzothiophene, their alkyl-substituted derivatives, and thioxanthene by the action of hydrogen peroxide in the presence of transition metal compounds (Na2MoO4, Na2WO4, NaVO3, WO3, tungstic acid, and heteropoly tungstate/molybdate H3PMo6W6O40) in a biphasic system followed by the extraction of the oxidation products with dimethylformamide has been studied. The oxidation of the hydrocarbon fraction in the presence of heteropoly tungstate/molybdate under biphasic conditions provides for the removal of up to 82% of total sulfur.

Oxidative desulfurization of catalytically cracked gasoline with hydrogen peroxide

Hydrogen peroxide desulfurization at 50°C of a catalytically cracked gasoline fraction containing methyl- and dimethylthiophenes and traces of benzothiophene and dibenzothiophene and boiling in the range of IBP-70°C in the presence of transition metal compounds Na2MoO4, Na2WO4, VOSO4, and [Cu(NH3)4]CO3 followed by adsorption on alumina has been studied. The successive oxidation of the hydrocarbon fraction in the presence of the copper and molybdenum compounds under phase transfer conditions ensures the removal of up to 96% of total sulfur.

Reduction of sulfur content in shale oil by oxidative desulfurization

The oxidative desulfurization of shale oil obtained by thermal extraction of organic matter from shale rock using an oxidative catalytic system composed of hydrogen peroxide, a molybdenum salt, and acids of different natures has been studied. It has been shown that the application of this method in combination with extraction of the oxidation products of organic sulfur compounds makes it possible to remove up to 94% of total sulfur from the synthetic oil.

Hydrogen peroxide oxidative desulfurization of model diesel mixtures using azacrown ethers

Hydrogen peroxide oxidative desulfurization of model diesel fuel mixtures in the presence of azacrown ethers and their complexes with niobium pentachloride at 40–80°C has been studied. It has been found that the use of complexes of azacrown ethers with NbCl5 leads to a decrease in the total sulfur content in the model mixtures to 13% of the initial amount. The structure of the azacrown ether used has little effect on the extent of desulfurization of the model mixture.

Synthesis, complex-formation, and extracting ability of new derivatives of dithia-13(16)-crown-4(5) ethers

Various methods of synthesizing functional derivatives of dithia-13(16)-crown-4(5) ethers are proposed. Complex-formation of the obtained compounds with Ag+ and Pb2+ ions has been studied using 1H NMR. A radiometric method was used to investigate the extracting ability of substituted dithia-13(16)-crown-4(5) ethers in relation to Ag+ and Cd2+ ions from aqueous solution in the presence of anions of various degree of hardness, with determination of the metal content.

Synthesis and extraction properties of oxathiacrown compounds containing benzyl groups

Abstract8-Benzyl-1.4-dioxa-7,10-dithiacyclododecane and 11-benzyl-1,4,7-trioxa-10,13-dithiacyclopentadecane were obtained by the interaction of (2,3-dibromo-1-propyl)benzene with 1,8-dimercapto-3,6-dioxaoctane and 1,11-dimercapto-3,6,9-trioxaundecane. The extracting ability of the obtained compounds has been studied in relation to Sr2+ and Pb2+ ions from aqueous solutions in the presence of anions of various degrees of hardness with determination of the metal content by a radiometric method.

Pyridine derivatives as ligands of metal complexes for the peroxidation of organosulfur compounds

Disubstituted pyridines, such as derivatives of 2,6-pyridinedicarboxylic acid, have ben synthesized and their peroxo complexes with tungsten and vanadyl ion have been prepared in situ. The activity of the complexes during the oxidation of sulfur-containing compounds of various diesel fractions has been shown.

Peroxide oxidative desulfurization of a mixture of nonhydrotreated vacuum gas oil and diesel fraction

Oxidative desulfurization of a model mixture on the basis of vacuum gas oil and diesel fuel by hydrogen peroxide in the presence of formic acid has been studied. A technology of a two-phase system with a phase-transfer catalyst has been employed for the desulfurization. The optimum reaction time is 6 h and the hydrogen peroxide: sulfur molar ratio is 4: 1. As a result of successive triple oxidative desulfurization, 90% of total sulfur is removed from the model mixture.

New functionalized dithia-12(13)-crown-4 ethers: Synthesis, complex formation, and extraction capacity

Abstract1,4-Dioxa-7,10-dithiacyclododecane-8-carbonitrile, 1,4-dioxa-7,11-dithiacyclotridecan-9-one, its 2,4-dinitrophenylhydrazone, and unsubstituted 7,10-dithia-12-crown-4 were synthesized. The complexing ability of the four synthesized dioxadithiacrown compounds toward Ag(I), Pb(II), Hg(II), and Cd(II) ions was assessed by 1H NMR. The extracting ability of the three dioxadithiacrown compounds with respect to the Sn(II) ion from aqueous solutions was studied. The thermal stability of 1,4-dioxa-7,10-dithia-cyclododecane and the corresponding 8-carbonitrile was investigated.

Synthesis and catalytic properties of niobium indenyl peroxo complexes

Synthesis of four niobium sandwich peroxo complexes containing fragments of substituted indenes was performed and their structure was proved by NMR spectroscopy and ESI-MS mass spectrometry. Catalytic activity of the complexes in the oxidation of sulfides with hydrogen peroxide was studied, and a high selectivity in the oxidation of sulfides to sulfoxides and sulfones of the sandwich peroxo complexes was found.