A. V. Tarakanova

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.

Oxidation of Organosulfur Compounds by Hydrogen Peroxide in the Presence of Niobium and Vanadium Peroxo Complexes

New niobium(V) peroxo complexes containing aspargine and Schiff base ligands were synthesized, and their structures were solved by IR, NMR, and mass spectrometric methods. They were found to be catalytically active for the peroxidation of methyl phenyl sulfide and benzothiophene to the corresponding sulfoxide and sulfones. It was shown that vanadium(V) peroxo complexes with the same ligands are less active in the oxidation of methyl phenyl sulfide than the niobium complexes.

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.

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.

Oxidative Desulfurization of Diesel Fuels in the Presence of Crown Ethers and Transition Metal Peroxo Complexes

The catalytic activity of crown ethers and their complexes with transition metal cations in diesel fuel desulfurization has been investigated. With dibenzo-18-crown-6 in combination with NbCl5, the total sulfur content of the fuel can be reduced by a factor of 2 or larger. The effects of the reaction temperature, nature of metal and crown ether, and sorbent acidity on the residual sulfur content are reported. Methods of separation of oxidized compounds, namely adsorption chromatography and extraction are compared in terms of desulfurization efficiency. The latter method is demonstrated to be preferable.

Oxidation of methylphenyl sulfide with hydrogen peroxide in the presence of crown ethers and their complexes with amino acids

The oxidation of methylphenyl sulfide, benzothiophene, and dibenzothiophene with hydrogen peroxide in the presence of crown ethers was studied. The major product of the oxidation was methylphenyl sulfoxide. The reaction was retarded by the addition of amino acids, which formed 1: 1 complexes with the crown ethers. The oxidation of the diesel fraction with hydrogen peroxide can decrease the sulfur content in it.

Treatment of Sulfide Alkali Waste Waters from Mercaptans Using Distillation

Processes of methyl and ethyl mercaptan extraction from solutions simulating oil-refinery sulfide alkali waste waters have been studied by distilling argon in the air and atmosphere. In the latter case, the amount of ethyl mercaptan extracted from alkaline solution reaches 94%.

Oxidative Desulfurization of Hydrocarbon Feedstock

Papers published in the past decade on oxidative desulfurization of hydrocarbon raw materials using hydrogen peroxide, oxygen, and ozone as oxidants, and also using ultrasonic treatment and adsorption and extraction methods for separating the oxidized sulfur-containing compounds are summarized and systematized.

Oxidative Desulfurization of Straight-Run Diesel Fraction

Oxidative desulfurization of straight-run nonhydrotreated diesel fraction with hydrogen peroxide in the presence of Na2MoO4 or Na2WO4, dibenzyl peroxide, and potassium permanganate; by air bubbling; and in the presence of ionic liquids has been studied. The oxidation products have been recovered from the oxidized diesel fraction using alumina, silica gel, or activated charcoal or via extraction with acetonitrile, N,N-dimethylformamide, or acetone. The best results of the diesel desulfurization have been achieved in the case of dibenzyl peroxide as an oxidizing agent in the presence of Na2MoO4.

Two-stage oxidative desulfurization of material containing oil sludge

The oxidative desulfurization of material containing oil sludge using hydrogen peroxide and transition metal compounds followed by subjecting the products of the oxidation of sulfur compounds to thermal treatment has enabled an 83% degree of desulfurization to be achieved.