The extraction of sulphur-containing compounds of diesel fuel (DF) with ionic liquids (IL) based on imidazole with various substituents (butyl, octyl, nonyl, dodecyl, cetyl) in position 1 of the imidazole ring has been studied; the composition of sulphur-containing compounds and polycyclic aromatic hydrocarbons (PAH) has been determined by gas chromatography - mass spectrometry in the initial and purified diesel fuel. The optimal extraction conditions are determined: temperature 30-35 °C, extraction time 60 min, DF/IL ratio 1.66-2. The most effective extractant for the sulphur-containing compounds of DF is 1-nonyl-3-methylimidazolium bromide, which allows reducing the total sulphur content from 0.369 to 0.143 wt%. Results of the studies of group and individual composition of dibenzothiophene (DBT) and PAH derivatives show that the degree of extraction of DBT derivatives and tricyclic aromatic hydrocarbons is 66-72 %. Naphthalene and its homologues are extracted to a lesser extent - 37 %. Among DBT homologues, dimethyldibenzothiophene is extracted most completely.

Two types of deep eutectic solvents (DES) have been synthesized for the extraction of sul-fur-containing (SS) compounds from the diesel fraction (DF). In DES of the first type the acceptor is ZnCl2, while the donors are glycerol, polyethylene glycol, ethylene glycol, butylene glycol, poly-propylene glycol, and n-butanol. In DES of the second type the acceptor is tetrabutylammonium bromide, while the donors are polyethylene glycol, glycerin, urea, imidazole, and phenol. Their extractive activity towards dibenzothiophene derivatives and cyclic sulfides was determined by using the diesel fraction (DF) as an example. The optimal conditions for the extraction process have been determined; hence the extraction time was 10-15 min. Extraction temperature in the range of 20 -40 degrees C has little effect on the extraction ability of DES. Extraction was carried out at 30 degrees C. The results obtained showed that there is a certain dependence of the residual content of SC in DF in the case of the extraction with zinc chloride and polyols served as DES. A monotone decreasing in the degree of extraction is observed in the series butanol -polypropylene glycol -polyethylene glycol -butylene glycol-triethylene glycol -glycerin -ethylene glycol. In the case of extraction of SC with DES based on tetrabutylammonium, the degree of extraction decreases in the series -PEG -G -EG -imidazole. The maximum degree of extraction of SC is achieved with such DES as ZnCl2-butanol andtetrabutylammonium bromide-phenol. The extraction of homologues of dibenzothio-phene and cyclic sulfides by the ZnCl2-butanol extraction system is located in the series: dimethyl-dibenzthiophene (100%) -methyldibenzthiophene (96.3%) -dibenzthiophene (74.7%) -cyclic sulfides (89%). The sequence of the extraction of SC in the tetrabutylammonium bromide-phenol system is the same: dimethyldibenzthiophene (98%) -methyldibenzthiophene (97%) -dibenzthio-phene (98%) -cyclic sulfides (74%)

The study investigated removal of metals (Ni, V, Cr, Fe, Ti, and Mo) from fuel oil using ultrasonic treatment (UST) and adsorbents such as carbon black, carbon nanotubes, aluminum oxyhydroxide (AlO(OH)), iron oxyhydroxide (FeO(OH)), and titanium dioxide (TiO2). Combined adsorption/UST provided a somewhat higher demetallization degree than the use of adsorbents alone. Compounds of iron, chromium, and molybdenum, which presumably complex with petroleum feedstock components due to intermolecular bonding, were removed almost completely (>95%). The removal of titanium compounds reached 60%. For these metals, no correlation between the removal degree and the physicochemical properties of the adsorbents was found. For vanadium and nickel, the highest removal degrees (37 and 23%, respectively) were achieved when an iron oxyhydroxide adsorbent was used in combination with UST. This can likely be associated with the superiority of the FeO(OH) adsorbent in negative surface charge and specific surface area compared to the other samples.

The process of removing sulphur-containing compounds from the diesel fraction has been carried out and investigated. The systems based on coordinating polar solvents (DMF and DMSO) and metal salts (CuCl2, CoCl2, MnCl2, Mn(TFA)2, Cu(TFA)2) were used as extractants. It has been established that the presence of metal salts in extraction systems increases the degree of removal of sulphur-containing compounds from the diesel fraction from 11 to 49 % and reduces the content of polycyclic aromatic hydrocarbons by 33 %. It is assumed that the addition of metal salts to the solvent enhances its acceptor properties, which is manifested in the enhancement of its extractability.

In the work there was considered the process of oxidative desulfurization of fuel oil with the use of hydrogen peroxide and a catalyst—titanium dioxide. It was found that oxidation of fuel oil by hydrogen peroxide in the presence of titanium dioxide can achieve SOC removal by more than 70%. The possibility of photooxidation of sulfur-containing organic compounds (SOC) of fuel oil and diesel fraction under UV irradiation in the range 370–385 nm in the presence of titanium dioxide is studied. Under UV irradiation of fuel oil, the photooxidation processes of SOC are insignificant, which does not lead to significant desulfurization. The study of irradiation of the diesel fraction with UV-light in the presence of a catalyst showed that the SOC photooxidation processes occur. When the diesel fraction is irradiated with UV-light with a wavelength of 380–385 nm and following removal of oxidized products by extraction, the sulfur content is reduced to 0.09 wt %.

The paper deals with the process of oxidative desulphurisation of oil with an initial sulphur content of 1.98% by weight. The process of oxidative desulphurisation was carried out with hydrogen peroxide in the presence of a carbon black (CB) catalyst with cobalt and nickel applied together. During the process of oxidative desulphurisation, the influence of the catalyst amount, temperature and the duration of the process were studied. In addition, the influence of the nature of the selected extractant on the efficiency of extraction of oxidised sulphurcontaining compounds (OSC) was studied. It was found that the maximum degree of OSC extraction is achieved during the oxidation process in the presence of a catalyst in an amount of 1.0–1.3% by weight, a temperature of 50°C and a duration of 90 min. The degree of removal of OSC was more than 70%. Dimethylformamide (DMF) with a water content of 10% by volume was used as extractant.

Many chemical processes are intensified by microwave radiation. The main factor determining the usefulness of microwaves in most transformations of organic compounds is the reaction time reduction to obtain the maximum yield of the target product. The presence of sulphur in oil and petroleum products is detrimental to refining equipment, and also has a negative impact on the environment in the form of waste generated during refining. In this connection development of methods on removal of sulphurcontaining compounds from oil products and oil by their transformation (in particular oxidation) and subsequent removal is very significant. Oxidative desulphurisation of fuel oil takes up to several hours depending on the reagents used. In this work an attempt has been made to significantly reduce the duration of the process. Oxidation of sulphur-containing organic compounds in fuel oil under microwave radiation has been considered, which proceeds in the presence of an oxidizer (hydrogen peroxide) and a catalyst (titanium dioxide). It was found that the oxidative desulphurization of fuel oil at microwave radiation proceeds effectively and quickly within 1--5 min. The achieved degree of desulphurization is 66 % when exposed to microwave radiation for 5 min. The influence of the amount of water in the reaction mixture on the efficiency of oxidative desulphurization of fuel oil under microwave radiation has been studied; it was found that the optimum ratio of water : fuel oil was (1--1.2) : 1

A composite material is manufactured on the basis of multiwalled carbon nanotubes (MWCNT) activated with nickel and cobalt. Its physicochemical and catalytic properties are investigated in the oxidation of sulphur-containing compounds (SC) of fuel oil with hydrogen peroxide. It is demonstrated by means of X-ray phase analysis and transmission electron microscopy that the material is composed of MWCNT phase and the phases of introduced metals (Ni and Co), with nanostructure represented by thin sheets 20 x 30 nm in size. The optimal conditions for the oxidation of sulphur-containing compounds of fuel oil were revealed: temperature, 50-60 degrees C; process duration, 90 min; catalyst content, 1.0-1.3 mass %; the ratio of sulphur in the raw material to the oxidizer was equal to 1 : 4. It was established that the most efficient system for the extraction of oxidized sulphur-containing compounds from fuel oil is dimethylformamide - water (10 vol. %) system. Under these conditions, it is possible to achieve a degree of sulphur removal of more than 75 %.

A composite material has been manufactured on the basis of multi-walled CNTs activated by nickel and cobalt. Its physicochemical and catalytic properties were investigated in the reaction of oxidative desulfurization of fuel oils. It was found out that the process of catalytic oxidative desulfurization of fuel oils occurred under mild conditions, i.e. at the temperature 50 degrees C, process time 90 min, catalyst content 1-1.3 wt %, and the molar ratio of sulfur of the feed to the oxidizing agent 1 : 4. The achieved level of sulfur removal was higher than 75%.

The possibility of removing sulfur-containing compounds from diesel fuel by extraction with ionic liquids (ILs) as extractants based on 1,3-dibutylimidazolium bromide and 1-butyl-3-octylimidazolium bromide and transition metal salts (Cu, Co, Ni, and Mn bromides and trifluoroacetates) has been considered. It has been shown that the use of extraction systems containing ILs and metal salts increases the degree of removal of sulfur compounds from diesel fuel. It has been suggested that metal salts with electron-withdrawing properties provide additional complexation with sulfur compounds of hydrocarbon feedstocks, which entails an increase in the extraction power of the extractant.

The photocatalysis process is widely used for removal of toxic chemical compounds from water and air. Oxides, sulfides of semiconductor materials are used as catalysts in photochemical processes, one of which is titanium dioxide. The manufacturing of an effective catalyst – nanotubes of titanium dioxide and the study of its physicochemical characteristics are considered in this paper. The behavior of titanium dioxide with various structures in the course of removing sulfur-containing organic compounds from diesel oil fractions is investigated. It is found out that titanium dioxide nanotubes (NT) are the most efficient catalysts for the photooxidation. Photocatalytic treatment of diesel fractions allows efficient and simple purification of oil products from unwanted components.

The possibility of the extractive desulfurization of diesel fuel using ionic liquids as extractants is considered. The ionic liquids are based on 1,3-alkylimidazolium bromide and transition metal salts. It is shown that the addition of metal salts to ionic liquids increases the degree of removal of sulfur-containing compounds from diesel fuel. It is likely that metal salts possessing electron-withdrawing properties provide additional formation of complexes with sulfur compounds of the hydrocarbon feedstock, which results in an increase in the extraction capacity of the extractant.

Titanium dioxide nanotubes were synthesised using industrial rutile pigments under the optimum conditions selected. Physicochemical properties and the catalytic activity of the former were examined. As shown, oxidation of sulphur compounds of diesel fraction in the presence of titanium dioxide nanotube-based catalysts allows simple and efficient treatment of oil products.

Composite metal–carbon materials are created on the basis of different kinds of carbon (multiwall carbon nanotubes, carbon black, Sibunit carbon–carbon material) and metals (Ag, Ni, Co), and their physicochemical and catalytic properties are investigated. It is shown that interaction between metals and carbon carriers proceeds not only with the functional groups on the surfaces of the carriers, but also through a system of–C–C–conjugated bonds. Silver deposited on the surface of a carbon carrier has a crystalline structure ( d cr = 10–15 nm), while nickel has an amorphous lamellar structure. Based on quantum-chemical calculations using the density functional theory, it is shown that cumene oxidation occurs via a homogeneous–heterogeneous mechanism.

Настоящая статья посвящена исследованию каталитической активности композиционных материалов «металл ? углеродный носитель» на основе различных видов углерода (углеродные нанотрубки, технический углерод, углерод-углеродный материал Сибунит) и металлов (Ag, Ni, Co) в реакции окисления кумола молекулярным кислородом. Процесс окисления кумола при температуре 60?°С и атмосферном давлении без катализатора и инициатора практически не идет (отсутствуют даже следовые количества продуктов реакции), т.е. термическое окисление не оказывает влияния на кинетику его каталитического окисления, и, вероятно, зарождение радикалов осуществляется на поверхности катализатора, который является одновременно и инициатором данного процесса, а окисление в целом проходит по гомогенно-гетерогенному механизму. Показано, что использование композиционного материала «Ag ? углеродный носитель в реакции окисления позволяет существенно снизить температуру реакции (до 40?°С) и повысить селективность по гидроперекиси. При использовании металлов переменной валентности в составе катализатора происходит разложение гидроперекиси по механизму Габера ? Вейса, при этом снижается селективность по гидроперекиси.

Catalytic systems for cumene oxidation were prepared on the basis of silver-activated carbon nanotubes. Silver lies on the surface of the carbon nanotubes in the nanocrystalline state and has a size of 15–20 nm. The use of the obtained catalytic systems in cumene oxidation with molecular oxygen allowed a considerable decrease in the oxidation temperature and an increase in selectivity.

Созданы каталитические системы для процесса окисления кумола на основе активированных серебром углеродных нанотрубок. Показано, что серебро находится на поверхности углеродных нанотрубок в нанокристаллическом состоянии и имеет размеры 15-20 нм. Сделан вывод, что использование полученных каталитических систем в процессе окисления кумола молекулярным кислородом позволило существенно снизить температуру процесса и повысить селективность.