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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.

A number of cracking catalyst samples containing Me–Mg–Al mixed oxides have been prepared. Cobalt, zinc, copper, and cerium were used as additional metals in the mixed oxide composition. When studying the cracking of a vacuum gas oil–sunflower oil mixture, catalysts containing Co–Mg–Al or Zn–Mg–Al mixed oxides were found to increase both the conversion rate of the mixed feedstock by 5.0 wt % compared to a sample containing the mixed oxide free of additional metal, and the gasoline yield by 1.6–3.0 wt %. It was discovered that the modification of mixed oxides with cobalt or zinc cations has no significant effect on the distribution of inorganic products, thereby indicating sustained catalytic activity during the decarboxylation reaction. The catalytic tests also demonstrated that catalyst samples containing mixed Mg–Al oxides with copper cations exhibited enhanced decarbonylation effect, as well as low conversion rates of the mixed feedstock and low gasoline yield, which is probably associated with the poisoning impact of copper oxide on Y zeolite.

The effect of the rare-earth element (REE) content in dual-zeolite cracking catalysts on the conversion of n-dodecane and an n-dodecane–2-methylthiophene mixture (5000 ppm S) has been studied. The catalysts have been synthesized using zeolites Y and ZSM-5 modified with REEs and phosphorus, respectively, as the active component. It has been shown that the presence of REE oxides in zeolite Y (at a constant SiO2/Al2O3 ratio) affects the catalytic activity of cracking catalysts based on this zeolite. The dependence of the light olefin yield on the REE oxide content in zeolite Y passes through a maximum at 2–3 wt %. The presence of a sulfur compound in an amount of 5000 ppm (in terms of sulfur) in the feedstock leads to a decrease in the model hydrocarbon conversion and the C2–C4 olefin yield. In the presence of a sulfur compound, the change in the C2–C4 olefin yield as a function of REE oxide content in zeolite Y is less pronounced than that in the case of individual n-dodecane cracking.

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 influence of the alkali treatment of ZSM-5 zeolites with a silica ratio of 30 within the NaOH : SiO2 molar ratio of 0 : 230, as well as the modification of a ZSM-5 zeolite with phosphorus in the range of 0–8 wt %, on the physicochemical properties and activity in hydrogen transfer reactions in the case of conversion of aliphatic alcohols has been studied. The alkali treatment of the zeolite leads to a decrease in the zeolite silica ratio and a growth in the hydrogen transfer coefficient in the case of transformation of aliphatic alcohols. The modification of the zeolite with phosphorus is equivalent to an increase in the zeolite silica ratio, which leads to a decrease in the hydrogen transfer coefficient.

Characteristic features of the conversion of n-hexadecane, hexene-1, cyclohexane, and their mixtures over dual-zeolite catalysts for co-cracking of light and heavy fractions are considered. The maximum yield of olefins (the yield of C2–C4 olefins reaches 66.8 wt %) is achieved in the case of the use of hexene-1 possessing maximum reactivity under cracking conditions as a feedstock. Cotransformation of n-hexadecane and hexene-1 do not indicate the presence of any significant interaction between the components. The presence of cyclohexane in the feedstock has substantial influence on the transformation of n-hexadecane, which is due to the high hydrogen donor ability of naphthenes. It is found that the ratio of HREEY and P/HZSM-5 zeolites in the composition of the catalyst has substantial influence on the value of the interaction between the components of the feedstock. The use of hydrocarbons containing “labeled” hydrogen atoms (deuterium) makes it possible to estimate the distribution of the naphthene hydrogen between the main gaseous products.

The effects of temperature (540–640°C), weight hour space velocity (1.0–7.0 h–1), and steam : raw material ratios (0–2.5) on the yield of C2–C4 olefins, conversion, and octane characteristics in the cracking of a mixture of model hydrocarbons (cyclohexane and 1-hexene) were studied. The influence of the structure of zeolites in mono-, bi-, and tri-zeolite catalysts on the distribution of cracking products was examined. It was found that the combination of catalyst components in bi- and tri-zeolite systems makes it possible to increase the efficiency of the consecutive cracking of hydrocarbons (C6–C12 → C4–C8 → C3–C6 → C2–C4) according to the following reaction scheme: matrix → ZSM-5 → FER. The maximum total yield of C2–C4 olefins (50.2 wt % at a conversion of 75.5%) was achieved with the use of a bi-zeolite catalyst of ZSM-5 + FER.

The activities of a zeolite-containing catalyst and catalysts containing a noble metal in intermolecular hydrogen transfer between С6 hydrocarbons are compared. The zeolite-containing catalyst is ineffective in hydrogen transfer from cyclohexane to 1-hexene and in cyclohexene conversion at

A refining process without the use of molecular hydrogen or zeolite-containing catalyst for lowgrade gasoline fractions is developed at the Institute of the Petroleum and Petrochemical Industry, Siberian Branch, Russian Academy of Sciences, and AO Gazpromneft-ONPZ. The processing of a mixture of coking gasoline and straight-run gasoline fraction of 62–85° reduces the content of unsaturated compounds by 90–95 wt % and that of sulfur compounds by 95–99 wt %, while improving the octane characteristics of the gasoline product by 3–5 points. The catalyst is based on the ultra-stable Y-type zeolite produced in HREE-form by AO Gazpromneft-ONPZ. This technology is unique and has no analogs.

The effect of temperature (530–590°C), weight hourly space velocity (2.5–7.0 h–1), and the Si/Al ratio of the ZSM-5 zeolite (30, 55, 80, 300) on the cracking of a butane–butylene fraction containing 85 wt % butylenes has been studied. The HZSM-5 zeolite has been modified with phosphorus. The effect of modification on the catalyst activity in cracking reactions has been studied. The ethylene and propylene yield achieves 38.4 wt % at a degree of conversion of butylenes of 81.5%. The ethylene to propylene ratio is 0.55.

Zinc (0.51 and 1.15 wt. %) was deposited by impregnation of HZSM-5 zeolite with an aqueous solution of Zn(NO3)2. Zinc modification of the HZSM-5 type (SiO2/Al2O3 = 30) affects the catalytic activity of cracking catalysts based on it in the aromatization reaction. The introduction of zinc leads to an increase in the yield of aromatic compounds compared with unmodified zeolite HZSM-5 from 44.5 to 47.4 wt. % (1.0-Zn-ZSM-5) during catalytic cracking of hydrotreated vacuum gas oil and from 41.8 to 45.8 wt. % for non-purified vacuum gas oil. Modification of zeolite HZSM- 5 with zinc does not significantly affect the yield of C2−C4−olefins. An increase in the rate of hydrogen transfer reaction is observed with an increase in the zinc content in zeolite HZSM-5, which leads to a decrease in the content of sulfur compounds in cracking gasoline.

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 effect of the mordenite acidic modulus (SiO2/Al2O3, 20 and 30) of Pt/MOR/Al2O3 catalysts on the heptane isomerization reaction is investigated. The content of zeolite in the catalysts is varied from 10 to 50 wt %, with platinum applied to the samples from solutions of different precursors: H2PtCl6 and [Pt(NH3)4]Cl2. It is established via the TPD of ammonia and FTIR spectroscopy (the adsorption of NH3 and СО) that the total acidity of zeolite falls as the modulus grows: the number of Bronsted (BAC) and Lewis (LAC) acidic sites is reduced, accompanied by an increase in the strength of their acidity. The catalysts are tested in the n-heptane isomerization reaction. It is shown that the selectivity of n-heptane isomerization falls substantially when the acidic mordenite modulus is increased from 20 to 30.

The mechanism of hydrogen transfers from naphthenes (methylcyclohexane, cyclohexane) or their deuterated derivatives to 1-hexene was specified over model acid zeolite catalysts (HREY or HZSM5). The composition of products is determined by two reactions-cracking and intermolecular hydrogen transfer. The monomolecular cracking reaction proceeds mostly on HZSM-5 zeolite, whereas the bimolecular hydrogen transfer reactions are catalyzed by the wide-pore HREY zeolite. It was found that during the hydrogen transfer from the naphthene molecule (hydrogen donor) to the olefin molecule (hydrogen acceptor) only one hydrogen atom is transferred, whereas the second hydrogen atom comes from the Bronsted acid site of the catalyst.

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.

Additives have been synthesized and tested to reduce the content of CO and NOx oxides in the gases of regeneration of FCC without the use of noble metals. The following can be used as additives to reduce CO: mixed oxides based on copper, cerium, magnesium and aluminum. According to the efficiency (89.7-95.5%) of the reduction in the CO content, mixed oxides based on copper and cerium are comparable with the additive based on platinum KO-10 (96.8%). All additives to reduce CO lead to an increase in the formation of NOx oxides. Additives based on mixed oxides (47.0%) are less conducive to this compared to platinum based additives (71.0%). Zeolite ZSM-5 modified with copper and iron can be used as an additive with the function of joint reduction of CO and NOx oxides. The effectiveness of reducing CO is close to 100%, and for NOx oxides it is 45.9%.

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 of the rare earth elements (REEs) content in range from 0 to 3 wt.% in the cracking catalyst on n-undecane and cumene transformations in the presence of heterocyclic sulfur and nitrogen compounds was studied. The catalyst samples acidity increased at raising the REEs content in the catalysts up to 2 wt.%. The catalyst acidity was sharply reduced with a further increase in the REEs. This phenomenon led to an enhanced conversion of the feed and a decreased formation of highly poisonous nitrogen compounds. The relative conversions of n-undecane and cumene in the presence of nitrogen and sulfur compounds were 95 and 97 rel.%, accordingly.

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).

Hydrogen transfer reactions in the transformations of mixtures of model hydrocarbons (hydrogen donors and acceptors) on zeolite catalysts were studied. Hydrogen donors were represented by various classes of hydrocarbons, and acceptors—by unsaturated (olefin) and thiophene compounds. The [H]-donor activity series of hydrocarbons was revealed. Strong differences in the transformation pathways of 1-hexene and 1-octene under the conditions of catalytic refining were demonstrated. A new method for the refining of low-rank gasoline fractions was proposed. The method is based on the hydrogen transfer reactions between hydrogen donor hydrocarbons and hydrogen acceptor hydrocarbons, which proceed without molecular hydrogen. The proposed method allows the simultaneous removal of sulfur (more than 95%) and unsaturated (more than 90%) compounds.

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.

The routes of transformation of vegetable oils under catalytic cracking conditions have been investigated. The influence of the component composition of the catalyst on distribution of the desired cracking products and their chemical group composition has been revealed. It has been shown that introduction of H-ZSM-5 zeolite into the composition of the oil cracking catalyst promotes the formation of C2-C4 light olefins—the yield of propylene and butylene mainly increases. During cracking on bizeolites catalysts, high yields of both gasoline fractions and light olefins are observed. The relationship between the unsaturation index of the vegetable oils and the product distribution during their catalytic cracking has been established. Oils with a high index of unsaturation are cracked on the bizeolite catalyst yielding primarily mono- and polyaromatic hydrocarbons.

Supported platinum catalysts based on ferrierite type zeolite with Pt content in the range of 1.3–2.8 wt % are prepared. The localization of Pt in zeolite channels is studied for the first time. It is shown that the platinum localized in them increases the yield of products from the selective hydrocracking of n-hexane. Platinum on the outer surface of the zeolite crystals participates in the transformation of n-hexane in the direction of forming hydrocarbons with isomeric structure. The catalysts can be used to improve the octane rating of reformed gasoline, owing to the selective removal of low-octane n-paraffin hydrocarbons and the increase of the portion of high-octane isoparaffin hydrocarbons in the catalytic reforming gasolines.

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.

The product distribution for the deep catalytic cracking of C16-C28n-alkanes has been studied. Using the method of the temperature-programmed desorption of ammonia, the difference in the acid properties of HZSM-5 and ultrastable Y zeolites and the catalyst matrix components has been found. For the primary cracking of heavy hydrocarbon feedstock to occur, the catalyst matrix must have a high acidity. Bizeolite catalysts exhibit high selectivities for olefins with both normal and branched chains, which are due to a decrease in the contribution of the hydrogen redistribution reaction. For a bizeolite catalyst, the additivity of the selectivities for olefins and aromatic hydrocarbons, depending on the composition of the zeolite component, is observed.

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.