Kh. M. Kadiev

Synthesis and properties of nanosized systems as efficient catalysts for hydroconversion of heavy petroleum feedstock

The review summarizes published data on the synthesis, physicochemical properties, and activity of nanocatalysts for the hydroconversion of heavy hydrocarbon feedstocks—atmospheric and vacuum residues. New reaction systems used in the hydroconversion of heavy feedstocks—a slurry reactor and a blacking reactor—are discussed. Particular attention is given to the synthesis of promising nanocatalysts by singlelayer dispersion of powders and thermal or chemical conversion of oil- and water-soluble precursors dispersed in a hydrocarbon medium.

Synthesis and use of polyfunctional catalyst nanoparticles for hydroconversion of natural bitumen

The results of the hydroconversion of high-molecular-mass bitumen components in a mixture with light gasoil after catalytic cracking in the presence of in situ synthesized novel polyfunctional nanocatalysts are presented. The influence of the composition and different modes of introduction of catalyst precursors on the conversion of the high-molecular-mass components and the yield of polycondensation products has been studied. The size, structure, and morphology of in situ forming nanoheterogeneous catalyst particles have been investigated. It has been found that binary nanocatalysts based on Fe1 − xS and MoS2 are the most active in the conversion of asphaltenes and the highest degree of desulfurization is achieved with the use of (Ni3S2 + MoS2)/Al2O3 and (Co9S8 + MoS2)/Al2O3 nanocatalysts.

Synthesis of nanosized particles of components of petroleum refining catalysts in a hydrocarbon medium from inverted microemulsions

The synthesis of suspensions of nanoparticles of molybdenum and aluminum oxides from inverted microemulsions with a dispersion medium composed of paraffin and aromatic hydrocarbons has been studied. The thermal decomposition of the precursors of catalyst components (water-soluble salts of Mo and Al) has been examined by thermogravimetric analysis and differential scanning calorimetry. The nature of the effect of the parameters of inverted microemulsions and conditions of their treatment on the particle size in the target Al- and Mo-containing suspensions has been revealed. The dispersity and composition of the resulting suspensions of nanosized particles have been analyzed.

Integrated conversion of extra-heavy crude oil and petroleum residue with the recovery of vanadium, nickel, and molybdenum

Based on experimental and calculation studies, it was demonstrated that, after the hydroconversion of tars and other heavy petroleum residues in the presence of a nanosized catalyst based on MoS2 or MoS2 and NiS, V, Ni, and Mo were quantitatively transferred to high-boiling fractions (HBFs) with boiling temperatures of >420–520°C and coke. At coke yields of <0.5%, V, Ni, and Mo were almost completely concentrated in the HBF removed from the process. A hydrometallurgical process based on the treatment of ash and slag wastes (ASWs) with an ammonia solution of ammonium carbonate was developed. The resulting aqueous solution contained Mo and Ni compounds (nanosized catalyst precursors) with Mo recovery to 80% and V and Ni recovery of >10% (on a weight basis in a HBF or its mixture with coke). Vanadium was extracted as V2O5 from the aqueous solution. The extraction of V and Ni from the solid residue after hydrometallurgical processing into commercial products can be performed by currently available industrial processes.

Thermodynamic and quantum chemical study of the transformations and operation mechanism of molybdenum catalysts under hydrogenation conditions

Structural transformations and the mechanism of the operation of molybdenum-containing catalysts under hydrogenation conditions have been studied by chemical thermodynamics and quantum chemistry methods, as well as the role of sulfur compounds in this process. It has been shown that molybdenum disulfide, an effective hydrogenation catalyst, is produced via the reaction of molybdenum oxide with hydrogen sulfide, not elemental sulfur. It has been concluded that the introduction of elemental sulfur (which is subsequently converted into hydrogen sulfide) or an organic sulfur compound into the reaction system, on one hand, facilitates the transformation of molybdenum oxides into MoS2 and, on the other hand, yields the effective reagent H2S, which takes part in the disproportionation reactions involving hydrogen transfer.

Current status and prospects of demetallization of heavy petroleum feedstock (Review)

Comparative assessment of the prospects of development of heavy petroleum feedstock (HPF) upgrading technologies in terms of the possibility of removal and recovery of metals contained in the feedstock is presented. It has been shown that HPF demetallization with different efficiencies can be achieved as a result of destructive thermal conversion of the feedstock and nondestructive mass transfer processes. Solvent deasphalting is characterized by simplicity of engineering design and operating flexibility and makes it possible to remove both asphaltenes and metals, whose deposition leads to irreversible deactivation of oil refining catalysts. Promising lines in demetallization by destructive feedstock conversion are associated with processes that provide the highest degree of HPF conversion and the lowest yield of the unconverted residue, in which the feedstock metals are concentrated. In this regard, the development and implementation of petroleum residue upgrading technologies based on the slurry hydrocracking, fluid coking or flexicoking, and supercritical fluid extraction processes creates real prerequisites for the organization of high-conversion comprehensive processing of heavy oils with the isolation of a metal concentrate.

A study of structural transformations of asphaltene molecules during hydroconversion of vacuum residue at various temperatures in the presence of nanosized molybdenum disulfide particles

Elemental analysis, molecular mass, and 1H NMR data are presented for vacuum residue asphaltenes and the products of vacuum residue hydroconversion in the presence of nanosized MoS2 catalyst particles obtained “in situ” in the hydrocarbon medium. Structural group analysis of average asphaltene molecules has been performed and their structural units have been described. The main trends of change in the structural parameters of the molecules under the hydroconversion conditions and the effect of temperature on the character of these changes have been revealed.

Application of nanocatalytic systems for deep processing of coal and heavy petroleum feedstock

The specific features of the catalysis of deep processing (hydrogenation and gasification) of coal and hydroconversion of heavy petroleum feedstock are considered. It has been shown that it is reasonable to use new catalyst forms and catalyst introduction methods for the processing of these raw materials in view of their specific composition and properties (large size of molecules, thermal instability, and the presence of inorganic compounds in the feedstock). In particular, a dispersion of nanosized spherical particles of MoS2 in a liquid hydrocarbon medium is an effective catalyst for the coal hydrogenation and heavy-oil hydrocon-version processes. Gaseous alkali metal hydroxides have been proposed for the gasification of solid fuels. The mechanisms of the formation of catalyst systems and some of their properties are discussed.

Catalytic cracking in today’s deep-conversion refinery

A trend in the development of catalytic cracking, one of the most important high-production-volume refinery processes, is integration into deep-conversion refinery complexes. We address studies on variation in the diesel/gasoline ratio and the processing of vacuum tower bottoms, renewable biomass, and polymer-containing wastes in complex facilities involving catalytic cracking and hydroconversion on nanosized heterogeneous catalysts.

Hydroconversion of polyethylene and tire rubber in a mixture with heavy oil residues

The results of studies on the processing of solid polymer wastes in a mixture with the heavy petroleum residues by hydroconversion with the use of the precursors of nanosized catalysts are given. It was found that the results of their TGA, kinetic parameters (weight losses, the temperature of a maximum rate of decomposition, and the rate constant of decomposition), and data on hydroconversion under the same conditions (the yields of gas, liquid products, and solid residue) are essentially different because of differences in the structural characteristics of polyethylene, tire rubber, and tar. The positive influence of linear polymers on their joint processing with tar was noted.