Straight-run Gasoline Research Articles

Composition of gasolinefractions of Kumkol oil and improvement of theiroperational properties

The physicochemical properties of gasoline fractions of paraffinic oil from the Kumkol field have been investigated and the distinctive features of the individual hydrocarbon composition of the straight-run gasoline fraction and catalytic reforming gasoline have been established. The wide straight-run gasoline fraction (62-180°C) of Kumkol oil was subjected to preliminary hydrotreating at an industrial unit that is part of the catalytic reforming unit using S-12T and GO70 catalysts at a process temperature of 315 – 343°C, a pressure in the reactor of 21 – 27 atm, a volume feed rate of 6.4 – 9.4 h-1, with the circulation of HCG (Hydrogen-containing gas) «on the duct». Conditions under which catalytic reforming was carried out: temperature in the reaction zone – 470 ÷ 500°C, pressure – 28 kgf/cm2 , volumetric feed rate of raw materials – 1.5 h-1, gas circulation – 5.9 mol H2 / mol of raw materials. It has been established that in the process of reforming, as a result of isomerization of n-paraffins and dehydrogenation of cylanes, isoparaffin and aromatic hydrocarbons are intensively formed in the composition of reformant, and thereby the octane number of reforming gasoline is sharply increased. Gasoline obtained in the process of catalytic reforming from a narrow fraction of Kuikol oil meets the requirements for commercial, high-octane grades of motor fuel in all quality indicators. A significant synergistic effect has been established with the combined action of a two-component mixture compared to that for individual additives: a small concentration of the additive Hightech (manganese-containing) 18 mg/l and oxygen-containing AHA (ash-free high-octane additive) increases the octane number M.M. (motor method) by 3.3 points and according to R.M. (research method) by 5.3 points, and when introducing the additive Hitech 18 mg/l in a mixture with N-methylaniline, the increase in the O.N. (octane number) for M.M. was 4.4 units, and for R.M. (research method) – 6.

STUDY OF THE COMBINED EFFECT OF POST-SYNTHETIC ALKALINE TREATMENT AND NICKEL MODIFICATION OF MFI ZEOLITE ON THE DYNAMICS OF ITS DEACTIVATION IN THE PROCESS OF REFINING STRAIGHT-RUN GASOLINE

To determine the combined effect of post-synthetic treatments on the catalytic properties of MFI type zeolite (other names ZSM-5 or pentasil) during the upgrading of straight-run gasoline fraction of oil, MFI zeolite was synthesized and on its basis a sample was obtained, treated with an alkaline solution, as well as a nickel-containing sample after alkaline treatment of the zeolite. Modification of zeolite powder treated with an alkaline solution with nanosized nickel powder was carried out by dry mechanical mixing of the original powders in a vibrating mill. The activity and dynamics of deactivation of the obtained zeolite catalysts during the upgrading of straight-run gasoline fraction of oil were studied. Along with determining the characteristics of the target reaction products - high-octane gasoline, an analysis of the resulting gaseous hydrocarbons was carried out and the amount of carbon compaction products was determined. It has been shown that post-synthetic treatments of zeolite have a positive effect on the qualitative composition and yield of catalysates and reduce the rate of deactivation of zeolite catalysts. Post-synthetic alkaline treatment of MFI zeolite significantly reduces its aromatizing and cracking activity, resulting in an increased yield of high-octane gasoline with improved environmental characteristics. The introduction of nickel nanopowder into alkali-treated zeolite further enhances this tendency. Carrying out post-synthetic treatments of zeolite increases the time of stable operation of the resulting zeolite systems in the process of upgrading straight-run gasoline and reduces the amount of carbon compaction products formed. The state, location and dimensions of the zeolite carrier, nickel particles and carbon compaction products were determined using the transmission electron microscopy method. It has been shown that oxidative regeneration of a carbonized catalyst makes it possible to almost completely remove the resulting carbon deposits from the surface of both the active component and the zeolite support. For citation: Velichkina L.M., Gerasimov E.Yu., Vosmerikov A.V. Study of the combined effect of post-synthetic alkaline treatment and nickel modification of MFI zeolite on the dynamics of its deactivation in the process of refining straight-run gasoline. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 8. P. 103-112. DOI: 10.6060/ivkkt.20246708.10t.

Hydroprocessing of Gasoline on Modified Alumina Catalysts

The hydroprocessing of gasoline on modified alumina catalysts makes it possible to obtain high-octane products. The implementation and development of the process have largely become possible due to the development of modified alumina catalysts that do not contain noble metals and exhibit special catalytic properties. This article discusses topical issues of petrochemistry, namely the creation of catalysts with improved characteristics for the production of high-octane gasoline with low sulfur content. New catalytic systems based on alumina and other carriers modified with transition metals, lanthanum and phosphorus were synthesized. By physico-chemical methods of analysis TPD of ammonia, TEM and XRD, we studied the acid–base and structural characteristics of the developed catalysts. The activity of the developed catalysts in the studied process of hydrotreating gasoline fractions depends on the structure and condition of the active centers. The process of hydrotreating straight-run gasoline in the presence of synthesized catalysts was carried out on a laboratory flow unit. It was shown that, during the hydrotreating of straight-run gasoline on the NiO-MoO3-La-P-HZSM-HY-Al2O3 catalyst, the octane number in the final product increased to 88.6, and the sulfur content decreased from 0.0088 to 0.001%. It was found that the minimum sulfur content in the gasoline hydrotreating product of 0.0005% was achieved on the catalyst CoO-WO3-La-P-HZSM-HY-Al2O3, which is significantly lower than for other studied catalytic systems. The obtained results of the sulfur content in the hydrotreating products fully comply with the Euro-5 standard. Thus, the efficiency of hydrotreating the gasoline fractions studied in this work was mainly determined by the nature of the carriers and modifiers used for the synthesis of catalysts and the technological parameters of the process. The synthesized catalysts showed high activity and selectivity, resulting in high-octane gasoline with a low sulfur content that meets international quality standards.

Determining the optimal parameters of hydrostabilization process of pyro-condensate in the presence of a nickel-chrome catalyst with the method of mathematical statistics

The aim of the work was to obtain mathematical static estimates of the influence of various factors on the degree of hydrostabilization of pyrocondensate obtained during the pyrolysis of straight-run gasoline, and an attempt to determine the most optimal process mode. The experimental data obtained earlier made it possible to determine the temperature range, duration, volume of the catalyst, and the ratio of hydrogen to feedstock necessary for the effective hydrostabilization of the pyrocondensate, which made it possible to narrow the range of variation of the process parameters. At the same time, the task was set to find the optimal conditions that ensure the maximum degree of hydrogenation of the condensate. The planning of the experiment was carried out according to the scheme of a full factorial experiment 24. According to the results of an active experiment carried out using mathematical planning methods, the major role of variable factors was determined, a mathematical model was obtained, and the optimal mode for conducting the pyro-condensate hydrostabilization process with the presence of a nickel-chromium catalyst was determined: temperature - 80° C, the ratio of hydrogen volume to raw material, equal to 0.3, catalyst volume - 5 sm3, process duration - 120 min. The temperature has the greatest influence on the degree of pyro-condensate hydrogenation.

The State of Modifying Additives in Iron-Containing Zeolite Catalysts and of Coke Deposits Formed on Them During the Conversion of Straight-Run Gasoline

The State of Modifying Additives in Iron-Containing Zeolite Catalysts and of Coke Deposits Formed on Them During the Conversion of Straight-Run Gasoline

Isomerization conversion of straight run gasoline, gas gasoline and their mixture on Co/HZSM-5/ZrO2/SO4 composite catalyst

Isomerization conversion of straight run gasoline, gas gasoline and their mixture on Co/HZSM-5/ZrO2/SO4 composite catalyst

Boosting oxidative desulfurization from liquid fuels with CuO-MgO assisted by MgMoO4 co-catalyst

Developing a highly efficient catalyst is one of the important topics in the field of oxidative desulfurization from liquid fuels. In this study, the composite metal oxide catalysts (CuO-MgO) with co-catalyst MgMoO4 were prepared by co-precipitation method with simple process, high efficiency and good performance and their structures characterized. An efficient extractive catalytic oxidative desulfurization (ECODS) system for liquid fuel was successfully developed on the basis of as-prepared CuO-MgO-MgMoO4 (CuMgMo) as the catalyst, sodium hypochlorite (NaClO) as the oxidant, and acetonitrile as the extractant. Taking the n-decane and n-tetradecane containing dibenzothiophene (DBT) as the test model oil sample, the main parameters influencing desulfurization performance were examined in detail, such as the molybdenum content, the dosage of CuMgMo, the reaction temperature, the initial S-concentration, the different extractants, the volume ratio of extractant to oil, the different oxidants, and the molar ratio of NaClO to DBT. Based on optimized desulfurization reaction conditions, the model oil containing different sulfur compounds (benzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene) and the real oil (straight-run gasoline, straight-run kerosene, and straight-run diesel) were further tested. Based on the free radical trapping experiments and the calculation of density functional theory, the reaction mechanism was deeply explored. The results showed that the de-electron reaction of DBT was mainly catalyzed by MgMoO4 and the reaction of HClO obtaining electron was mainly catalyzed by CuO. MgMoO4 plays an assisting role in improving the catalytic reaction rate. This work will provide a useful reference for the construction of efficient ECODS system using composite metal oxides.

Gasoline Fraction High-Efficient Sweetening by Gas Condensate Oxidation and Rectification

The results of the oxidative desulfurization process (combination of straight-run gasoline fraction and gas condensate oxidation with subsequent rectification) are presented. It is shown for the first time that it is possible to obtain a gasoline fraction with ultra-low sulfur content by oxidation and rectification of gas condensate. Optimum conditions have been selected for the process of sulfur compounds oxidation and subsequent rectification of gas condensate.

Effectiveness of methyl tert-butyl ether and ethynylcyclohexanol on increasing the octane number of gasoline compositions of straightrun gasoline + reforming

One of the ways to expand the production of high-octane unleaded gasoline is the use of oxygen-containing components (oxygenates). The addition of oxygenates increases the detonation resistance, especially of light fractions, the completeness of gasoline combustion, reduces fuel consumption and reduces the toxicity of exhaust gases. It was found that such an amount of oxygenates, despite their lower calorific value compared to gasoline, does not adversely affect the energy performance of engines. Oxygen-containing additives are complex and simple esters of monocarboxylic acids, higher alcohols, oxidized hydrocarbon fractions containing mixtures of acids, alcohols and esters, and oxyethylated compounds. Because of its high octane number, which allows the compression ratio to be increased to 16, methanol is used to fuel racing motorcycles and cars.The effect of ethynylcyclohexanol (ECH) and methyl tret-butyl ether (MTBE) on increasing the octane number of gasoline compositions has been evaluated by increasing the octane number of a 50:50 and 20:80 mixture of straight-run gasoline and reforming gasoline. It has been shown that ECH is an effective oxygen-containing additive (oxygenate) for increasing the octane number of gasoline compositions, compared with MTBE.

INFLUENCE OF THE PREPARATION METHOD OF BISMUTH-CONTAINING ZEOLITE CATALYSTS ON THEIR ACTIVITY IN STRAIGHT-RUN GASOLINE PROCESSING

New methods of zeolite HZSM-5 modification with bismuth compounds are proposed. The choice of bismuth as a modifying agent is due to the systematisation and generalisation of the available literature data and experimental results of studying the chemistry and synthesis of bismuth compounds of various compositions. Phases in the resulting bismuth-containing zeolite systems were identified by X-ray phase analysis, and the state of bismuth in chemical compounds was determined. The number and strength of acid sites in the original and modified samples were determined by the method of temperature-programmed desorption of ammonia. The catalytic activity of zeolites was studied in the process of hydrogen-free processing of the straight-run gasoline fraction of oil into high-octane gasolines. The effect of modification methods and process temperature on the structural-group hydrocarbon composition, the yield of gaseous and liquid reaction products was studied, and the octane numbers of the resulting gasolines were determined. It is shown that over the bismuth-containing zeolite catalysts, in comparison with unmodified zeolite, the yield of the target product, high-octane gasoline containing a smaller amount of aromatic hydrocarbons, increases, which makes it more environmentally friendly. It has been established that the production of high-octane gasolines that meet modern requirements for motor fuels is possible over modified zeolites within a wider process temperature range. Based on the studies performed, methods for modifying the HZSM-5 zeolite with bismuth are proposed on the basis of the studies performed. The proposed methods make it possible to improve the efficiency of the catalyst in the process of upgrading the straight-run gasoline fraction of oil.

Catalytic aerobic desulfurization of fuels in the presence of nanosized mixed carbide FeWC

Nanosized mixed tungsten-iron carbide (FeWC) was successfully applied in aerobic oxidative desulfurization. The combination of catalytically active centers responsible for the activation of oxygen and the oxidation of sulfur-containing compounds made it possible to obtain a highly efficient catalyst. The catalyst was synthesized by microwave irradiation, allowing to obtain a nanoscale catalyst in just 15 min. The catalyst was characterized in detail by a variety of methods: XRD, HRTEM, EDX, SEM, XPS, and low-temperature nitrogen adsorption/desorption. The key factors influencing the dibenzothiophene (DBT) oxidation were investigated. Under optimized conditions DBT conversion was 100% in 1 h at 130 °C, 6 atm. The possible mechanisms including oxygen activation, alkyl peroxide formation, and substrate oxidation by tungsten peroxo-complexes were discussed. The catalyst retains its activity for at least 5 cycles of oxidation-regeneration. Aerobic oxidative desulfurization of straight-run gasoline in the presence of FeWC was performed and sulfur content was reduced from 995 to 6 ppm.

Influence of the Preparation Method of Bismuth-Containing Zeolite Catalysts on Their Activity in Straight-Run Gasoline Processing

Influence of the Preparation Method of Bismuth-Containing Zeolite Catalysts on Their Activity in Straight-Run Gasoline Processing

Превращение стабильного гидрогенизата на каталитических системах Pt/ЦВМ, Pr/ЦВМ

Catalytic reforming is the most used method for upgrading straight-run gasolines. The trends to modernize catalytic systems so that the reforming process can be used in the industrial setting are focused on the production of catalysts with a specific set of characteristics allowing to obtain a liquid commercial product with the required operational and ecological features, in addition to increase its yield at lower temperatures. This article investigates the efficiency of the catalytic systems Pt/CVM, Pr/CVM as transformation processes of raw hydrocarbons. A high molecular weight ZSM zeolite (ZSM-5) has been used as a carrier. The raw material that has been used is a stable hydrogenate obtained through hydrotreatment, which is the main raw material of the reforming process. The octane number of the hydrogenate is 63, which is not acceptable for automobile gasolines. The transformation of the crude material results in the production of liquid fuel made up of multiple components and carbon atoms in a chain ranging from 3 to 14 atoms, as well as gases containing hydrocarbons С1 – С5. In this work, the transformation of a stable hydrogenate on the catalysts under investigation has showed that temperature increase results in a higher octane number and aromatic content. It has been determined that temperature increase results in the reduction of the effects of the isomerization reaction, with a subsequent decrease in isoparaffinic content. With a transformation of a stable hydrogenate on the catalyst Pt/СVM at temperature of 400°С, the benzene content amounts to 0,8 wt. %, which corresponds to the EURO-5 automobile gasoline standard.

Deep aerobic desulfurization of fuels over iron–сontaining zeolite based catalysts

Herein, we present a new approach to the design of the catalysts for aerobic oxidation of sulfur-containing compounds. Iron-containing zeolite-based (ZSM-5, ZSM-12) catalysts were synthesized and successfully tested in oxidation of model mixtures as well as real petroleum fractions. The catalysts were characterized by means of X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM), ultraviolet–visible spectroscopy (UV/Vis), temperature programmed desorption of ammonia (NH3-TPD), and low-temperature nitrogen adsorption-desorption. Among these catalysts Fe-ZSM-12 demonstrated the best activity: exhaustive oxidation of dibenzothiophene (DBT) in the presence of this catalyst was achieved in 2 h at 150°C. Influence of the reaction conditions (temperature, amount of catalyst, and time) on the conversion of the model substrate was studied. It was shown that in the presence of Fe-ZSM-12 catalyst activation of molecular oxygen proceeds via formation of superoxide radical. Fe-ZSM-12 exhibited an excellent stability and retained its activity after 10 cycles of oxidation. Under optimal reaction conditions sulfur content in straight-run gasoline fraction was reduced from 807 to 43 ppm, in diesel fraction – from 1898 to 150 ppm. Two-dimensional GC-MS analysis of diesel fraction before and after desulfurization indicates high selectivity of the process. Possibility of sulfur dioxide formation during the aerobic oxidative desulfurization process was studied for the first time. The use of zeolite-based catalysts containing transition metals for aerobic oxidation of sulfur-containing compounds is a promising approach for clean fuel production.

Sulfur containing mixed wastes in anaerobic processing by new immobilized synthetic consortia

Methanogenic biotransformation of unusual substrates (sulfur (S)-containing wastes: non-purified vacuum gas oil, straight-run gasoline fraction (Naphtha), gas condensate, and straight-run diesel fraction) coming from oil industry after their oxidative desulfurization was investigated. Nitrogen-containing wastes (hydrolysates of chicken manure and Chlorella vulgaris biomass) were added as co-substrates to mixture with oil industry wastes. The 100 % conversion of S-organic compounds to inorganic sulfide accumulated in the reaction liquid medium was achieved with simultaneous production of biogas containing high methane percent (greater than 70 %). Polishing of effluents from methane tank was carried out by denitrifying oxidation of ammonium (DEAMOX). The high process efficiency was due to use of original immobilized artificial consortia at the stage of methanogenesis and DEAMOX. This study reveals the real potential in the processing of very complex mixtures of large-scale wastes, usually inhibiting methanogenesis, by developing biocatalysts based on synthetic biology approaches.

FORENSIC INVESTIGATION OF OXYGENATES IN MOTOR TYPES OF GASOLINE

The main types of oxygenates, which are used in the manufacture of motor types of gasoline, are considered. Oxygenates (oxygen-containing compounds) is the general name for lower alcohols and ethers used as high-octane components of motor fuels. For the manufacture of motor types of gasoline, a low-octane base is used to which high-octane components are added. In many cases, lower alcohols (methanol, ethanol, etc.) and ethers (methyl tert-butyl ether, tert-amyl methyl ether, etc.) are used as high-octane components of motor types of gasoline. Straight-run gasoline and stable gasoline are often used as the low-octane gasoline base for mixed motor types of gasoline. Methanol (CH3OH) is the simplest monohydric alcohol. Methyl alcohol is now produced synthetically from carbon monoxide (CO) and hydrogen (H2). Ethanol (ethyl alcohol) is a representative of monohydric alcohols with the formula C2H5OH. The production of ethyl alcohol is possible in several ways: biochemical, hydrolysis, synthetic, or ethylene hydration. For the manufacture of motor types of gasoline, dehydrated ethyl alcohol (bioethanol, an alternative universal component of motor fuel (KMPU), etc.) is used. Bioethanol is produced according to DSTU 7166: 2010 “Bioethanol. Technical mind”. According to DSTU 7166: 2010, bioethanol is dehydrated ethyl alcohol made from biomass or from raw ethyl alcohol for use as biofuel. As a technological and denaturing additive, gasoline (petroleum products) is introduced into bioethanol in an amount of up to 1.5 % by volume. KMPU is produced in accordance with TU U 20.5-00372536-001: 2013 “Component of firing motor alternative universal (KMPU). Technical conditions”. An alternative universal motor fuel component is dehydrated ethyl alcohol with a complex of additives, which is used for the manufacture of mixed motor types of gasoline and alternative types of motor types of gasoline. Compositionally, KMPU is similar to bioethanol but differs from it in the presence of another high-octane component – methyl tert-butyl ether (MTBE). Methyl tert-butyl ether, formula CH3-O-C (CH3)3 is a product that can be obtained in large quantities by reacting isobutylene with methanol. The advantage of MTBE is its good solubility in gasoline, and, at the same time, it is not washed out of it with water. MTBE does not impair the physical and chemical stability of gasoline; it is characterized by stable anti-knock properties during storage and operation. The article discusses the results of the study of the listed oxygenates by gasliquid chromatography. This method makes it possible to establish the qualitative and quantitative composition of oxygenates and motor types of gasoline based on them. It is shown that from readily available petroleum components (stable gas gasoline) without the use of complex technological equipment by mixing with oxygenates, it is possible to obtain a gasoline mixture with a high detonation resistance, which is fake gasoline in composition. When mixing in certain proportions a low-octane gasoline base, for example, stable gas gasoline and oxygenates (lower alcohols, ethers), which have appropriate performance characteristics, it is possible to obtain commercial gasoline that will meet the requirements of regulatory documents (DSTU) for motor types of gasoline. The considered technology also allows, when mixing in the calculated proportions of commercial gasoline A-92 (A-95) with oxygenates and stable gasoline, to improve the operational characteristics (knock resistance) of the obtained gasoline mixture or to increase the volume of the resulting gasoline mixture without improving its operational characteristics. Key words: blended types of gasoline, alternative types of gasoline, oxygenates, lower alcohols, ethers, bioethanol, alternative motor fuel component universal.

Conversion of model C6–C9 alkanes and straight-run gasoline over Pt(0.1%)-Fe(5%)/Al2O3 catalysts promoted with various additives

Growing demand for hydrogen promotes the research devoted to the development of new catalysts for hydrocarbons processing in absence of H2 or at its low concentration. In the present work, it was shown that during the conversion of straight-run gasoline on a zeolite-containing polyfunctional catalyst in a hydrogen-free environment cracking, dehydrogenation, isomerization and alkylation take place due to the redistribution of H2 between initial and formed products directly on the catalyst surface. Fine particles (≤50 Å) localize in zeolite cavities and pores of aluminum oxide, while larger ones are on their outer surface.

IMPROVING THE ENVIRONMENTALITY OF MOTOR GASOLINE

The article considers measures aimed at improving the environmental situation of large cities by reducing the harmful effects of exhaust gases generated during the operation of road transport. It is substantiated that a direct increase in the environmental friendliness of motor gasoline is the most promising approach to reducing the toxicity of exhaust gases. This increase can be achieved by reducing dissolved hydrocarbon gases (C4H10 and iso-C4H10) and metals (Pb, Fe, Mn) in gasoline; facilitation of the fractional composition of gasoline (including the end-boiling temperature); reduction in gasoline content of sulfur, aromatic hydrocarbons and olefins. Reducing these undesirable, from an environmental point of view, components will improve the quality of gasoline to the Euro-5 requirements adopted in Ukraine, as well as significantly extend the service life of special catalysts installed on motor vehicles to clean exhaust gases.
 The effect on the gasoline fraction (PK – 180 °C) and commercial gasoline A-95, oxygenates (methyl tert-butyl ether and ethyl alcohol) and 1,3-diphenyltriazene was studied. It is established that the use of 1% of the mass. 1,3-diphenyltriazene, in the composition of straight-run gasoline allows to increase its resistance to detonation by 12 points, reduce the toxicity of exhaust gases by 24% in terms of CO and 17% in terms of CH. It was determined that the addition of 1,3-diphenyltriazene to commercial gasoline A-95 in the amount of 1% by weight, in contrast to oxygenates, does not lead to a deterioration in the evaporation of gasolines and their physical stability.
 The use of 1,3-diphenyltriazene in commercial gasoline, due to its positive properties, in the future will optimize the use of other additives, including oxygenates, which are widely used today in the technology of commercial gasoline.

Oxidative desulfurization of the straight-run gasoline fraction from the gas condensate of the Karachaganak field

An annual increase in the consumption of the automobile fuels makes us look for new ways of their obtaining. It is also important that the environmental and operational requirements for the quality of the motor fuels, obtained during oil production (associated petroleum gas, gas condensate) are systematically made more rigorous. One of the ways to solve the problems described above is to use the process of oxidative desulfurization to improve the quality of the petroleum products. In this case, oxidative desulfurization of the straight-run gasoline fraction, obtained from the gas condensate of the Karachaganak field, has been carried out. The oxidation process has been carried out with hydrogen peroxide in the presence of salts of the transition metals, molybdenum and vanadium. The optimal technological parameters (Patm, T=600C, 2 h, H2O2:S=4:1 (mol), Me:S=1:100 (mol)) of the oxidation process for the straight-run gasoline fractions have been selected. Under the optimal conditions of the oxidation process, the total sulfur content has been reduced by 89.9%. It has been shown that the molybdenum compounds exhibit greater activity in the oxidation of sulfur-containing compounds at a temperature of 600C, as compared to the vanadium compounds. A schematic diagram of the purification of the gasoline fractions from the sulfur-containing compounds by oxidative desulfurization, followed by its extraction desulfurization with the most effective N,N-dimethylformamide has been presented.

MECHANISM OF CATALYTIC ISOMERIZATION–DISPROPORTIONATION PROCESSING OF STRAIGHT-RUN GASOLINE

The isomerization-disproportionation conversion of straight-run gasoline over the Co/HZSM/SO42--ZrO2 (SZ) composite catalytic system at atmospheric hydrogen pressure has been studied. Optimal process conditions (1800С; Н2/СН=3; WHSV = 2.5 h-1) was established, under which the conversion of С8+ hydrocarbons is 77.3%, and the sum of high-octane gasoline components С5–С6 alkanes increases from 11% to 61%. Тhe effect of C4-, C5–C6 products and H2O on this isomerization-disproportionation process have been studied. It is shown that, unlike the main C5–C6 products, side C4-products affect the stability of the process, and the catalyst is deactivated under the water's influence. Comparative studies of the conversion of a mixture of straight-run gasoline and C2H5OH showed that H2O vapor formed sites deactivate the centers located on the SZ. It has been established that the mechanism of isomerization-disproportionation conversion of straight-run gasoline with the participation of a composite catalytic system is realized through the conjugated interaction of red-ox centers contained on SZ with acid-base centers of Co/HZSM-5, responsible, respectively, for the formation of intermediate compounds [С4+C7] and their and their further hydro cleavage