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The features of cracking catalysts produced by aluminosilicate technology are described. Approaches to designing cracking catalysts for processing various types of materials (light, heavy, mixed) are shown. The main methods for modifying components and properties of catalysts prepared on their basis are presented. Methods for reducing catalyst activity in hydrogen transfer reactions (for catalysts prepared by aluminosilicate technology) are shown. The achievable yields of olefins on the described catalysts are 35 and 50 wt.% at processing heavy and light feedstock types respectively. The influence of the feedstock hydrotreating degree on the yield of light olefins is considered.

The present work studies the influence of nitrogen compounds in hydrotreated fluid catalytic cracking (FCC) feedstock on the material balance of FCC process focused on petrochemistry. Vacuum gas oil was hydrotreated at the temperatures of 340–370 °C in typical FCC pretreatment conditions. The obtained hydrotreated products contained 370−750 ppm of nitrogen and 150−820 ppm of sulfur. Hydrotreated feedstock was exposed to the FCC process over a zeolite catalyst at the laboratory unit with a fixed bed catalyst at 527 °C and catalyst/oil ratio - 2−6. The FCC feedstock before and after hydrotreatment and FCC products were characterized by different methods to study the effect of nitrogen compounds on the FCC process.

This paper describes the investigation of the individual effects of the introduced quantities of rare-earth elements (REE) and of SiO2/Al2O3 ratio on the physicochemical characteristics (textural properties and acidity) of Y zeolite, as well as on the catalytic activity of petrochemical cracking catalysts based on the zeolites prepared, during the conversion of hydrotreated vacuum gas oil (HTVGO). The amounts of REE oxides and the zeolite SiO2/Al2O3 ratio were quantified independently. An increase in REE oxide content in zeolite reduces its acidity. With an increase in SiO2/Al2O3 ratio at constant REE oxide content, the concentration of acid sites decreases, while the specific surface area and pore volume change only insignificantly. A growth in the REE2O3 content leads to a decline in the olefin yield from HTVGO cracking. Catalytic tests of the prepared catalysts demonstrated that an increase in SiO2/Al2O3 ratio enhances the C2–C4 olefin yield from HTVGO cracking as a result of the smaller contribution of hydrogen transfer reactions.

The effect of the preliminary impregnation of zeolites HREY and HZSM-5 with ammonium phosphate before introducing them into the composition of dual-zeolite catalysts has been studied. It has been found that the modification leads to a change in the main textural characteristics of the zeolites. Both the specific surface area and the meso- and micropore volume of the zeolites decrease. The total acidity of HREY and HZSM-5 and the number of strong acid sites in them also decrease. Tests on the conversion of hydrotreated vacuum gas oil and a vacuum gas oil–sunflower oil mixture under catalytic cracking conditions have shown that the modification of the zeolites leads to an increase in the total yield of the propane–propylene and butane–butylene fractions with a high olefin content in them, even with a decrease in the feedstock conversion.

The study of cotransformation of petroleum fractions with vegetable oils on dual-zeolite cracking catalysts has revealed that vegetable oils differing in fatty acid composition admixed to vacuum gas oil, characterized by a high aromatics content, facilitate the conversion and increase the yields of the gasoline fraction and light olefins. In the case of vacuum gas oil cocracking with a vegetable oil having a high unsaturation index (sunflower oil), the oil content in the mixture should not exceed 5 wt %, since its higher content in the mixture leads to enhanced coking of the dual-zeolite catalyst and simultaneous reduction in the yield of the desired cracking products. The effect of preliminary impregnation of HREEY and HZSM-5 zeolites with ammonium hydrogen phosphate before their incorporation into the composition of dual-zeolite catalysts has been investigated as well. It has been found that the modification results in a decrease in the total acidity of zeolites. In the cracking of a mixture of vacuum gas oil and sunflower oil, it has been determined that the modification of zeolites leads to an increase in the total yield of the propane–propylene and butane–butylene fractions with high olefin content. Keywords: vacuum gas oil, vegetable oils, dual-zeolite catalyst, gasoline fraction

The effect of the main parameters (temperature, pressure, and dilution of the reaction medium with an inert gas) of such catalytic processes as the cracking of vacuum gasoil and the hydrogenless refining and cracking of gasoline fractions on the ratio of the selectivity of the cracking and intermolecular hydrogen-transfer reactions is studied. Control over the ratio of these reactions allows products to be obtained according to the requirements for processing feedstocks. An increase in the time of feedstock–catalyst contact, a reduction in the degree of diluting the reaction mixture with an inert gas, and a rise in pressure result in greater selectivity for hydrogen-transfer reactions. Experiments are performed on setups with fixed and recycled beds of zeolite-containing catalysts. The transformation of feedstocks containing deuterated compounds is investigated.

The studies were focused on the influence of key parameters (temperature, pressure, dilution of the reaction medium with an inert gas) of catalytic processes (cracking of vacuum gasoil, hydrogen-free upgrading and cracking of gasoline fractions) on the ratio of selectivities to cracking and intermolecular hydrogen transfer. Controlling the ratio of these reactions allows the required products to be obtained on the feedstock processing. Lengthening of the feedstock-catalyst contact time, a decrease in the proportion of the diluting inert gas, and the pressure rise provides an increase in the selectivity to hydrogen transfer. Fixed and circulating catalyst bed setups were used for the experiments. Transformations of the feedstock containing deuterated compounds were studied.

The influence of modifying HZSM-5 zeolite as a component of a bizeolite catalyst in transformations of hydrotreated vacuum gasoil, plant oil, and a mixture of vacuum gasoil and plant oil was studied. The modification with phosphorus was established to decrease the specific surface area and meso- and macropore volumes in HZSM-5 zeolite; the higher phosphorus content, the lower main characteristics of the zeolite porous structure. A decrease in the total acidity of P/HZSM-5 and quantitative redistribution between weak and moderate acid sites also was observed. Testing of the zeolites in catalytic cracking revealed that the phosphorus modification favored an increase in the total yield of propane-propylene and butane-butylene fractions containing olefins in high proportions. Alkali treatment of HZSM-4 zeolite with a high silicate module resulted in a higher silicon extraction and in a considerable increase in the specific surface area of mesopores. In addition, strong acid sites of the zeolite were transformed to weaker ones and/or their exposure changed due to partial silicon removal.

After processing the product of thermochemical activation of gibbsite (TCA product), aluminum hydroxide samples were obtained. The effect of temperature and duration of the stages of hydration and hydrothermal treatment on the physicochemical characteristics of aluminum hydroxide is studied. Hydration in a slightly acidic environment leads to the predominant formation of boehmite phase. It is shown that with an increase in the temperature of hydrothermal treatment, the size of the coherent scattering region decreases. The surface area depending on the temperature of the hydrothermal treatment practically does not change. When the hydrothermal treatment stage lasts less than 5 hours, the formation of a two-phase product is observed.

The effect of the phosphorus in zeolite ZSM-5 as a component of cracking catalysts, was studied on the conversion of pure n-dodecane, as well as its mixture with 2-methylthiophene in an amount of 5000 ppm sulfur. It was established that the modification of zeolite ZSM-5 with phosphorus affects the catalytic activity of catalysts based on it. The maximum yield of C2−C4−olefinic hydrocarbons is observed at a phosphorus content of 4 wt. % in zeolite ZSM-5. Modification of zeolite ZSM-5 with phosphorus reduces the degree of conversion of thiophene compounds by reducing the contribution of intermolecular hydrogen transfer and as a result increasing the content of sulfur compounds in cracking liquid products.

The regularities of the transformation of sunflower oil and a mixture of vacuum gas oil with sunflower oil under catalytic cracking conditions are investigated. The influence of the catalyst composition on the distribution of target cracking products has been established. It is shown that the introduction of zeolite HZSM-5 into the composition of the catalyst favors the formation of olefins C3 and C4. The effect of preliminary impregnation of zeolites before their inclusion in the composition of bizeolite catalysts was investigated. It is determined that the modification of zeolites with phosphorus results in a decrease in both the specific surface area and the volume of micropores of zeolites. In addition, a decrease in the total acidity of HREY and HZSM-5 is observed. It is found that a modification of zeolites results to increase yields propane-propylene and butane-butylene fractions with a high olefin content, when transformation is mixtures of vacuum gas with sunflower oil under cracking conditions, even at lower conversion of the feedstock.

The catalytic properties of catalysts based on ZSM-5 zeolites with modules 30, 80, 300, as well as samples of these zeolites modified with phosphorus during cracking of butane-butylene fraction (BBF) and butanols (1-butanol, 2- butanol, isobutanol) were investigated. The growth of the module of zeolite ZSM-5, not modified by phosphorus, contributes to an increase in the yield of ethylene and propylene. The highest yield of C2-C3 olefins is obtained on H- ZSM-5 zeolite with a module of 300. Modifying zeolites with phosphorus reduces the acidity of the zeolite and leads to a decrease in the conversion of the feedstock and system activity in hydrogen transfer reactions.

It was investigated additives to the cracking catalyst for increase their resistance to the poisoning effect of feed nitrogen compounds. It was shown that the use of clays, activated of 5% sulfuric acid solutions andmixed magnesium- aluminum oxides modified with cobalt, allows to increase the activity of the catalysts and to ensure a high yield of the gasoline fraction at the content 0.10% wt. from quinoline in the feed. Additives based on zeolite ZSM-5 were used to reduce the content of NOx oxides in the gases of regeneration of spent catalysts. The effectiveness of reducing oxides of NOx for the best nitrogen-resistant catalyst is up to 69.0% when using zeolite ZSM-5, available iron.

The joint catalytic cracking of heavy and light fractions (n-hexadecane in a mixture with cyclohexane and hexene-1) was investigated. The influence of the active component composition and the cracking process conditions (temperature, dilution with inert gas) on the conversion of thiophenic compounds with hydrocarbons was studied. The ratio of zeolites P/ZSM-5 and HREEY affects the cracking reactions: hydrogen transfer ratio. An increase in the proportion of wide-porous zeolite Y leads to a decrease in the selectivity of the formation of C2-C4-olefins.

The effect the content of rare-earth elements has on thermostable and catalytic properties of HREEY zeolite in the composition of a catalyst matrix consisting of bentonite clay, amorphous aluminosilicate, and aluminum hydroxide is considered. It is established that when the content of rare-earth elements is increased from 0 to 6.5 wt %, the thermostability of the zeolite rises by approximately 100°C. It is shown that increasing the content of rare-earth elements in the catalyst from 0 to 2 wt % raises the conversion of vacuum gasoil by 8 wt %. An acceptable 77–78% level of the conversion of raw materials is achieved when the REE content in the catalyst is approximately 0.5 wt %. The dependence of the contribution from hydrogen transfer reactions to the REE content in the cracking catalyst is shown as an example of a change in iso-butane content in the sum of formed C4-hydrocarbons. Based on laboratory data, a technique for the production of bizeolite cracking catalysts with reduced contents of REEs (M, N brands) is developed and introduced for catalyst production at JSC Gazpromneft-Omsk Oil Refinery.

The stacked beds comprising hydrotreating catalyst as the top layer, hydrocracking catalyst based on amorphous silica-alumina as the interlayer and hydrocracking catalyst based on USY zeolite as the bottom layer were tested in hydrocracking of mixed feed containing straight-run VGO, heavy coker gas oil, aromatic extract and petrolatum. It is shown that stacked beds with developed catalysts can be successfully used both in the once-through hydrocracking to provide VGO conversion of 70–80% with middle distillates yields up to 50 wt% and in the first stage operation of two stages hydrocracker to provide 35–65% VGO conversion and produce high-quality middle distillates and feed for the second stage. The commercial partner of this work is Gazprom Neft PJSC (Gazprom Neft Omsk Refinery).

The effect of the composition of zeolite containing catalyst, the conditions of conducting the process, and the nature of oils on the distribution of target products during conversion under conditions of catalytic cracking is studied. The study is performed on bizeolite catalysts containing zeolites (ultrastable Y and ZSM-5 at different ratios) and on catalyst LUX containing18 wt % of zeolite Y in the HREY form. It is shown that the presence of zeolite ZSM-5 in the catalyst composition promotes the formation of olefines C2–C4. An increase in the severity of cracking process (elevated temperatures and catalyst: raw material ratios) improves the yield of gaseous products and coke with a simultaneous reduction in the yield of the gasoline fraction. The effect the nature of vegetable oils has is studied using the examples of palm, rapeseed, mustard, and sunflower oils. It is demonstrated that for the maximum yield of olefines C2–C4 and gasoline, we must use oils with elevated contents of saturated fatty acids. The regularities of the simultaneous cracking of sunflower oil and vacuum gas oil are studied. It is been found that upon simultaneous cracking, the total conversion of the mixed feedstock and yield of gasoline fraction increase; the maximum effect is attained with the addition of 3–10 wt % of vegetable oil.

With the purpose of increasing the yield of light C2-C4 olefins in comparison with that in conventional catalytic cracking, we experimentally study the effect of temperature and catalyst-to-oil ratio on the distribution of the basic products of oil catalytic cracking on the bizeolite and industrial LUX catalysts. The bizeolite catalyst contains ZSM-5 and ultrastable Y zeolites in equivalent amounts, while the LUX catalyst contains 18 wt % of Y zeolite in the HRE form. As shown by the results of our tests, the yield of C2-C4 olefins and gasoline in the deep catalytic cracking of hydrotreated vacuum gasoil on the bizeolite catalyst within a range of catalyst-to-oil ratios of 5–7 and temperatures of 540–560°C reaches 32–36 and nearly 30 wt %, respectively. In cracking on the LUX catalyst under similar conditions, the yield of light olefins and gasoline is 12–16 and 37–45 wt %, respectively. The distribution of target products in the deep catalytic cracking of different hydrocarbon fractions (vacuum gasoil, gas condensate, its fraction distilled from the cut boiling below 216°C, and the hydrocracking heavy residue) on the bizeolite catalyst is studied. It is shown that the fractions of gas condensate and hydroc-racking residue can serve as an additional source of hydrocarbon raw materials in the production of olefins.

With the purpose of improving the durability of the industrial cracking catalyst Lyuks, the influence of ultrasonic treatment (UST) on the dispersion, durability, hydrophilia, and phase structure of components of the cracking catalyst and catalytic compositions as a whole were studied for the first time. The composition of an industrially manufactured cracking catalyst consists of montmorillonite, the product of hydrargillite thermoactivation, amorphous silica-alumina, and zeolite Y. Applying the ultrasonic treatment to suspensions of individual components of the catalytic composition results in growing their dispersion, at which point is discovered an increase of hydrophilia of montmorillonite particles, an alteration of velocities of aluminium hydroxide phase changes, and an improvement of the durability of calcinated montmorillonite extrudates from 200 to 300 kg/cm2. The ultrasonic treatment of the suspension of the cracking catalyst composition also leads to growing its dispersion, thereby improving the durability from 80 to 125 kg/cm2 and bulk density of the ready cracking catalyst on retention of the high catalytic activity without modifying its structure and incorporation of an additional peptization stage used traditionally for this purpose.

Stability of the crystal structure of zeolites Y and ZSM-5 in the presence of the most frequently used matrix components was studied under conditions of thermal and hydrothermal treatments at high temperatures.

A historical review of the perfection of oil cracking catalysts, including problems of modifying the zeolite component and the chemical and phase structure of the catalyst matrix is presented. The role of matrix components in the formation of effective cracking catalysts is discussed. The mechanism of formation of the active centers and secondary porous structure of the zeolite component under high-temperature steam ultrastabilization conditions is considered. Data on the catalytic systems for oil cracking, developed at the IHP SB RAS, are given.

The texture characteristics and strength properties of the molded alumina–montmorillonite composite are studied. The mixture is obtained by mixing suspensions of activated clay and pseudoboehmite followed by drying (at 293 and 393 K) and calcination (at 873 K). It is a promising support for cracking and hydrotreating catalysts. The changes in the specific surface area; the volumes of micro-, meso-, macropore, and medium-size pores; and the strength of samples are studied by varying the montmorillonite concentration in the composite. The addition of 20–35 wt % clay largely results in a sharp in reduction of the macropore region and, correspondingly, provides the alumina oxide average strength of the extrudates of ∼10–12 MN/m2, which is sufficient for industrial supports. This excludes the stage of standard acidic peptization from the technological scheme of alumina production. The complex study of the porous structure of the composite by adsorption and mercury porosimetry combined with elements of percolation theory makes it possible to predict the texture–strength properties of derivative materials.

The article discusses the properties of several model zirconium dioxide complexes (ZrO(2))(n)() intercalated into the interlayer space of montmorillonite clay. Grand canonical Monte Carlo simulation was used in a series of numerical experiments during analysis of the low-temperature nitrogen adsorption in the micropores thus generated. The goal of such experiments was to determine the geometrical parameters of introduced molecular complexes of different types inside micropores of various widths. The obtained information was used to characterize textural and structural properties of three pillared interlayer materials prepared by using pillaring species synthesized via aging of zirconyl chloride solutions containing as additives chlorides of Ca, Sr, or Ba. It was found that in the cases of Ba and Ca the interlayer micropores are filled with isolated tetramers (ZrO(2))(4). Meanwhile, the presence of Sr in the pillaring solution, most likely, favors the preservation of larger sheetlike complexes (ZrO(2))(8).

Modeling of high resolution nitrogen adsorption isotherms by the Grand Canonical Monte Carlo (GCMC) method for zirconia-pillared clays containing 20 wt.% of ZrO2 revealed that the pillars are comprised of separate Zr4(μ-OH)8(OH)m (H2O)n units (Zr4 tetramers) and their dimers (Zr8 complexes) as sheets or loose 3D structures. This agrees with the results of modeling of the condensation process in solution using the Density Functional Theory approach (DFT) and the semiempirical PM3 method. Bridging and terminal hydroxyls strongly bound with Zr cations are involved in anchoring supported Cu cations and Pt. This nanostructure of the active component as well as the developed micro- and mesoporosity appear to be responsible for the high performance of Pt+Cu/ZrPILC catalysts in the NOx selective reduction by propylene and decane in realistic feeds.