Nickel-based catalysts for hydrodeoxygenation of vegetable oils are an alternative to the systems based on noble metals and sulfide catalysts for hydrotreatment. Modification of the nickel catalysts with molybdenum and copper allows the yield of target products to be increased and the corrosion resistance of the catalytic system to be improved. The studies were aimed at establishing relationships between temperature, contact time and activity of the modified nickel-containing catalyst to hydroxygenation of esters of fatty carboxylic acids, as well as at determining effective kinetic parameters of the reactant consumption. A flow reactor with the fixed catalyst bed was used for experimental studies at РН2 = 0.25 MPa, temperatures 270, 285, 300 and 315 °C, contact time varied from 600 to 1800 s. It was shown that the selectivity to the main reaction products – nonane and decane – did not change upon varying the reaction temperature and contact time. The experimental data were used for determining the effective rate constants and activation energy of the reaction.

The influence of the composition of the active component of copper-doped nickel catalysts on the activity and selectivity to hydrodeoxygenation (HDO) of model vegetable oils (esters) to eliminate oxygen and produce alkanes was studied. The Ni/Al2O3 andNi-Cu/Al2O3 catalysts were shown to be active to this process. They catalyzed HDO of a mixture of methyl ester of hexadecane acid and ethyl ester of decane acid to produce C6–C16 alkanes and oxygen-containing compounds, methane and ethane being detected in the gas phase. A decrease in the Ni/Cu ratio in the catalyst led to a decrease in the ester conversion and in the catalyst activity to hydrogenolysis of C–C bonds. Hence, the introduction of copper may favor preservation of the carbon skeleton of HDO-produced alkanes and a decrease in the methane yield. XRD studies revealed the formation of solid solutions Ni1–xCux upon addition of copper to the Ni/Al2O3 catalyst. From XPS data, an increase in the copper proportion in the Ni-Cu/Al2O3 catalyst resulted in a decrease in the Ni/Cu ration on the catalyst surface.

Data on the processing of secondary middle distillates are surveyed. Modern processes and technologies for the refining of secondary distillates to produce motor fuel components that meet the requirements of modern standards have been considered. Problems arising in relation to hydrofining of secondary feedstock with a high unsaturates and aromatics content are touched on.

Results are presented from studying the steam cracking of heavy oil at a temperature of 425°C and a pressure of 2.0 MPa over dispersed iron and molybdenum based catalysts in a slurry reactor. The catalysts are synthesized through the decomposition of water-soluble precursors of metal salts in situ. The yield of upgraded oil (the sum of liquid products) is found to grow with steam cracking, in comparison to thermal cracking (80 and 77%, respectively). The use of dispersed monometallic (iron- or molybdenum-containing) catalysts and a bimetallic catalyst for the catalytic steam cracking (CSC) of heavy oil increases the yield of SOPs. In addition, the yield of light fractions (Тb < 350°C) in the CSC process is found to grow in comparison to steam and thermal cracking, and the viscosity and density of products falls, relative to the initial feedstock.

The relevance of the research is caused by the need in developing alternative hydrogen-free technologies for processing heavy oil feedstocks to involve the latter in oil refining and increase the depth of processing of residues (atmospheric and vacuum residues) to minimize yield of by-products. The main aim of the research is to investigate catalytic steam cracking of vacuum residue of West-Siberian oil in the presence of dispersed catalysts based on various metals. Objects: catalytic steam cracking - thermocatalytic process of heavy oil feedstock upgrading in the presence of water. Methods. To assess the efficacy of catalysts based on various metals, a complex of physicochemical parameters: fractional composition of catalytic steam cracking liquid products (ASTM D7169-11), S content, H:C ratio (HCNS-O analysis), density and kinematic viscosity (ASTM D7042) of liquid products, was used. Results. The authors have determined the main features of steam catalytic cracking of vacuum residue at 450 degrees C in the presence of dispersed catalysts based on various metals (at a metal concentration in the initial emulsion of 0,5 wt. %). It was revealed that the use of a Mo-based dispersed catalyst leads to an increase of the H:C ratio (to 1,56) in liquid products comparing to steam cracking without a catalyst (1,32), also the sulfur content in liquid products decreases (by 0,22 wt. %), these facts indicate the enhancement of interaction between water and heavy feedstocks using this type of dispersed catalyst. The use of a dispersed catalyst based on iron, an increase in the yield of light fractions (29,3 wt. %) was noted, since this catalyst is characterized by high activity in oxidative cracking. The remaining dispersed catalysts based on Ni, Al, and Co do not exceed Mo -and Fe-based catalysts in the yield and quality of liquid products. The viscosity of liquid products is reduced by about 90 times compared with the original vacuum residue.

XRD, TEM, EXAFS/XANES methods are first used to study the structure and morphology of Mocontaining phases of carbon residues of heavy oil refining during catalytic steam cracking, catalytic cracking without water, and hydrocracking. According to the results obtained from physical and chemical studies of Mo-based catalytic phases, the reaction medium affects structural features of Mo-containing phases, e.g. the amount of oxide and sulphide forms, the particle size, and particle morphology.

In view of the worsening quality of crude oil, the use of unconventional petroleum feedstocks (heavy oils, bitumens, residues, etc.) in processing is becoming increasingly important. The processing of heavy oil feedstocks (HOF) requires the development of new effective techniques that will lead to an increase in the yield of light fractions, suppression of coke formation, and saturation of liquid products with hydrogen. At the same time, the capital and operating costs of the process should be minimized because the cost of production and transportation for HOF is several times higher than for light and middle oils. The present review summarizes the results of studies of the catalytic steam cracking of HOF—a potential alternative to conventional HOF upgrading based on carbon rejection (thermal cracking, visbreaking, catalytic cracking) or hydrogen addition (hydrocracking). The main differences of this process from HOF upgrading with water (aqueous pyrolysis in sub- or supercritical water), the peculiarities of the catalytic steam cracking depending on the process conditions and the type of catalyst, and possible mechanisms of water participation in the process were discussed.

The features of the steam cracking of heavy crude oil in the presence of a dispersed molybdenumcontaining catalyst are studied. The effect of water, the catalyst, and process conditions on the composition and properties of the products of the thermal conversion of heavy crude oil is determined in experiments on thermal cracking, steam cracking, catalytic cracking in the absence of water, and hydrocracking. A complex analysis of the resulting products is conducted; the catalyst-containing solid residue (coke) has been studied by XRD and HRTEM. The effect of the process temperature (425 and 450°C) and time on the yields and properties of the resulting products is studied. The efficiencies of hydrocracking and steam cracking for the production of upgraded low-viscosity semisynthetic oil are compared; the fundamental changes that occur in the catalyst during the studied processes are discussed. Some assumptions about the principle of the catalytic action of the molybdenum-containing catalyst in the steam cracking process are made.

The catalytic steam cracking (CSC) of heavy crude oil with high amount of sulfur (4.3 wt %) and high-boiling fractions (>500°C) is studied using Mo and Ni nanodispersed catalysts under static conditions (in an autoclave) at 425°C. Experiments on thermal cracking, steam cracking, and catalytic cracking without water are performed to compare and identify the features of CSC. The relationship between the composition and properties of liquid and gaseous products and process conditions, the type of catalyst, and water is studied. Using Ni catalyst in CSC raises the H: C ratio (1.69) in liquid products, compared to other types of cracking, but also increases the yield of coke and gaseous products, so the yield of liquid products falls. When Mo catalyst is used in CSC, low-viscosity semi-synthetic oil with a higher H: C ratio (1.70) and the lowest amount of sulfur in liquid products (2.8 wt %) is produced. XRF and HRTEM studies of the catalyst-containing solid residue (coke) show that under CSC conditions, nickel is present in the form of well-crystallized nanoparticles of Ni9S8 15–40 nm in size, while molybdenum exists in two phases: MoO2 and MoS2, the ratio between which depends on the conditions of the transformation of heavy crude oil. The findings indicate that CSC is a promising process for improving heavy crude oil.

In the review, the results of research in the field of heavy crudes upgrading in the presence of water are presented, depending on water phase states at temperatures ca. 150-550 degrees C. In this temperature region, water can be in the subcritical state (compressed hot water at T = 100 - 374 degrees C. and saturated water vapor pressure), in the form of supercritical fluid (T >= 374 degrees C, P >= 22.1 MPa) and in the form of superheated steam (at P < saturated water vapor pressure). Features of the heavy crudes upgrading including mechanisms of water involving in reactions with hydrocarbon feedstocks and model compounds as well as features of the use of catalysts are reviewed.

The process of heavy crude oil steam cracking using semi-flow (with respect to water) and steadystate regimes at 425°C without catalyst is investigated. It is established that in the case of a semi-flow regime, water acts predominantly as a physical agent facilitating the distillation of hydrocarbon fractions and thus preventing their transformation into petroleum coke. A reduction in coke yield is observed for a steady-state regime in comparison to a semi-flow regime; the introduction of water results in enhanced conversion of the high-boiling fraction and an increased yield of light fractions in the composition of liquid products. Based on the obtained data, it is concluded that water plays a positive role during the conversion of heavy crude oil, and that the steam cracking process is promising for production of lighter synthetic and/or semi-synthetic oils.

The process of heavy crude oil (HCO) steam cracking under a batch regime at 425°C in the presence of Ni-containing nanodispersed catalyst (0.3–2.0 wt % with respect to Ni) is investigated. It is established that using this catalyst facilitates the upgrading of semi-synthetic oil produced from HCO: the Н: С ratio rises (in comparison to steam cracking with no catalyst), and the sulfur content and viscosity are reduced. The Н: С ratio in the liquid products grows slightly along with the catalyst content, but the yield of liquid products falls from 81 to 76% during the process with a simultaneous increase in the yield of coke and gaseous products (from 8 to 13 and from 2 to 4 wt %, respectively). Catalyst with coke residue is investigated by means of XRD and TEM. It is shown that nanosized particles of the Ni9S8 phase with sizes of 15–40 nm form from the catalyst precursor (Ni(NO 3 ) 2 · 6H 2 O) under the process conditions. The selection and investigation of catalytic systems for heavy crude oil cracking in the presence of superheated steam, along with optimization of the process conditions, are required to further enhance the efficiency of the upgrading process.

Rice hulls (RH) is a paddy rice waste product difficult to recycle. The method of RH carbonation in a fluidized bed reactor with a catalyst developed as a way of RH utilization. The ash formed after carbonization at 465-600 °C is carbon-silica nanocomposite material (C/SiO2) containing SiO2 58,7–81,8 weight.% and specific surface SBET = 152–232 m2/g. The porous carbon material with a specific surface area 165–494 m2/g and SiO2 content less than 1% were received during leaching SiO2 by hydrofluoric acid. These materials were characterized by SAXS, TEM and X-ray diffraction. Information about the size of SiO2 particles in the carbon-silica nanocomposites is obtained for the first time. It is found that increases in temperature carbonization from 465 to 600 °C leads to an increase in average size of silica particles from 5,5 to 8,1 nm. It is shown the promise for the development of methods for determining the size of the silica particles in a carbon matrix by SAXS for targeted design of porous carbon materials with predetermined properties. The RH carbonation method in a fluidized bed of catalyst is one of the most promising in terms of processing in RH C/SiO2 nanocomposites and porous carbon materials using approaches template synthesis.