RU2676086C1 - Method for preparing universal bifunctional catalyst to convert synthesis gas and hydrocarbons to gasoline fractions - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to the field of catalytic synthesis of gasoline fractions from synthesis gas and processes for the conversion of hydrocarbons in a synthesis gas medium, in particular, to methods of preparing a universal bifunctional catalyst (BFC) for the above-mentioned processes, and can be used in the petrochemical and gas processing industries. Method is described for preparing a universal bifunctional catalyst for the conversion of synthesis gas and hydrocarbons into gasoline fractions, including separate grinding of the components of a metal oxide catalyst for methanol synthesis, namely, zinc and chromium oxides or zinc, chromium and aluminum oxides with an atomic ratio of Zn/Cr of less than 4, and zeolite component with a molar ratio of SiO₂/Al₂O₃ more than 12, having micropores with a size of more than 0.5 nm, mixing ground components of a metal oxide catalyst for methanol synthesis and a zeolite component to obtain a homogeneous mixture, adding to the mixture of aluminum oxide as a binder component, granulating the resulting mixture by extrusion, drying the extrudates made in air, crushing the extrudates to form granules of the catalytic composition and calcining the latter, the recovered metal oxide catalyst for methanol synthesis with the content of oxides of sodium and iron less than 0.04 wt.% each, having a 100 % degree of recovery and has not been exposed to temperatures of more than 400 °C in an airy, reducing or inert environment, and an acid component with a sodium oxide content of less than 0.04 wt.%, selected from a number of zeolites with the structure of ZSM-5, ZSM-12, Beta, having a molar ratio of SiO₂/Al₂O₃ more than 25, or from a series of crystalline silico-aluminophosphates with a SAPO-5 structure, or a combination of SAPO-5 with a zeolite of the ZSM-5 type, grind them to a particle size of less than 0.3 mm, add an active hydrogel of aluminum oxide or amorphous aluminum hydroxide and, if necessary, chemically purified water with pH of 6.5–7.5 is added to the resulting homogeneous mixture as a binder component, in the reduced metal oxide catalyst for methanol synthesis, in the acid and in the binder components, there are no water-soluble metal cations and anions of inorganic and organic acids, and the pH of the components of a bifunctional catalyst is in the range of 6.5–7.5, then the pasty mass obtained by mixing particles of the reduced metal oxide catalyst for methanol synthesis, acid and binder components at a temperature of 20–60 °C, is at least twice passed through a device for grinding materials, in which the cutting unit consists of a rotating figure knife, interacting with a fixed grid with through axial channels, and then subjected to a screw or piston extrusion at a temperature of 20–60 °C, and the drying of the extrudates obtained is carried out in two stages: first, at room temperature for at least 24 hours, and then at 120 °C for at least 4 hours, the granules formed as a result of crushing the dried extrudates should have a cylindrical shape with a diameter of 3–5 and a length of 8–12 mm, and calcining the manufactured granules is carried out after they are loaded into the synthesis gas conversion reactor with a fixed catalyst bed: initially – at a temperature of 200–320 °C in a nitrogen atmosphere, and then at a temperature of 320–400 °C in the environment of circulating synthesis gas, the multiplicity of the circulation of synthesis gas must be at least 10.

EFFECT: creating a method for preparing a durable and active universal BFC for the processes of converting synthesis gas and hydrocarbons into gasoline fractions with a moderate content (15–35 wt.%) of aromatic hydrocarbons, having a high selectivity of action – at least 75 wt.% of hydrocarbons C₅₊.

6 cl, 18 ex, 3 tbl, 1 dwg

Description

The invention relates to the field of catalytic synthesis of hydrocarbons from a mixture of CO, CO ₂ , H ₂ , N ₂ , CH ₄ (hereinafter referred to as synthesis gas), as well as processes for the alkylation of aromatic hydrocarbons with synthesis gas, methylation of liquid olefins with products of synthesis gas conversion, oligomerization gaseous olefins and aromatization of liquid n-paraffins in a synthesis gas medium, in particular, to bifunctional catalysts (BFC) and methods for their preparation for the above processes and can be used in petrochemical and gas processing yshlennosti.

Liquid hydrocarbon fractions obtained from synthesis gas using BFK can be used as gasoline with a low content of benzene and a moderate content of aromatic hydrocarbons. In addition, in the process of producing gasoline fractions, in order to increase their octane numbers and increase the yield of liquid hydrocarbons without replacing the BFC, various liquid or gaseous olefins, aromatic hydrocarbons, liquid n-paraffins can be added to the initial synthesis gas cycloparaffins or mixtures thereof of natural origin (gas condensate, straight-run fraction of oil, etc.) or synthetic liquid hydrocarbons obtained from synthesis gas by the Fischer-Tropsch synthesis method. Due to this, BFKs prepared by the proposed method are universal and can be used in various chemical processes: the conversion of synthesis gas to liquid hydrocarbons, the alkylation of aromatic hydrocarbons with synthesis gas, the methylation of liquid olefins with the products of synthesis gas conversion, oligomerization of gaseous olefins and aromatization liquid n-paraffins in a synthesis gas medium.

A known method of preparing a catalyst for the conversion of synthesis gas to liquid hydrocarbons [1]. In it, the hydrogen forms of zeolite ZSM-5 are obtained by double treatment with 1M ammonium nitrate solution or double treatment with 1M HCl solution followed by calcination at a temperature of 550 ° C. Then decationized zeolites are impregnated with the necessary quantities of solutions of cobalt nitrate, thorium nitrate and chromium nitrate. The impregnated zeolites are stirred in vacuo for 30 minutes, dried using microwave radiation, and then calcined at 500 ° C for 4 hours. After that, the resulting catalyst is pressed and a 1-2 mm fraction is taken for catalytic tests.

A known method of producing a catalyst for the Fischer-Tropsch synthesis process containing zeolite (ZSM-5, or ZSM-11, or ZSM-12, or ZSM-35, or ZSM-38) and the active component is Co, which is obtained by impregnation of the zeolite component an aqueous solution of cobalt nitrate in the ratio of 100 parts by weight of cobalt per 1000 parts by weight of the catalyst, followed by stirring in vacuo, drying using microwave radiation, calcining and pressing to obtain a fraction of 1-2 mm [2].

The main disadvantage of the above methods for the preparation of BFK is their technological complexity due to the use of vacuum and microwave radiation. In addition, the use of BFK data for the conversion of synthesis gas does not make it possible to obtain liquid gasoline fractions that can be used as high octane gasoline in one stage and in high yield.

Close to the present invention is a method for producing hydrocarbon gasoline fractions from a gas consisting of H ₂ and CO ₂ or H ₂ , CO ₂ and CO, by contacting this gas at a temperature of 320-440 ° C, a pressure of 4-10 MPa and a volume ratio of N ₂ / (CO + CO ₂ ) = 1-3 with BFK containing zeolite type ZSM-5 or ZSM-11. In this case, as the second (metal oxide) component, a composition of three or more metal oxides of the general formula is used: aCuO bZnO cAl ₂ O ₃ dCr ₂ O ₃ eW ₂ O ₅ , where: a, b, c, d and e are mass fractions of oxides metals in the metal oxide component (a = 0-56, b = 24-67, c = 0.6, d = 0-32, e = 0-1, provided that a and b cannot be simultaneously zero) [ 3].

According to this method, the target products of the conversion of a mixture of H ₂ , CO ₂ (and in some examples of H ₂ , CO ₂ and CO) are liquid gasoline fractions of hydrocarbons with a high content of aromatic hydrocarbons (from 40 to 84% wt.).

The main disadvantages of the known method for producing BFCs include the additional consumption of expensive hydrogen for the reduction of CO ₂ to CO, as well as the too high content of aromatic hydrocarbons in the obtained liquid gasoline fractions of hydrocarbons, which exceeds the permissible values for gasoline of ecological classes Euro-4, Euro-5 and Euro-6 (in which, according to the established requirements, there should be no more than 35% vol. Aromatic hydrocarbons).

Close to the present invention is a method for the conversion of synthesis gas to aromatic hydrocarbons [4], which describes in detail methods for the preparation of catalytic compositions containing a zeolite, mainly ZSM-5, and an oxide component including zinc and chromium oxides with an atomic ratio of Zn / Cr <4. When the synthesis gas is converted (Н ₂ / СО = 1) on ZnO-Cr ₂ O ₃ -Al ₂ O ₃ -ZSM-5 catalysts with different component ratios under conditions of a pressure of 8.4 MPa and a temperature of 427 ° C, hydrocarbon yields are 16 , 2-42.8% (per carbon), and the content of aromatic hydrocarbons reaches 69.7% wt. of the amount of hydrocarbons received.

The disadvantages of this method include: a high content of aromatic hydrocarbons in the obtained liquid gasoline fractions of hydrocarbons, which exceeds the permissible values for environmental gasolines of Euro-4, Euro-5 and Euro-6; low selectivity of ZnO-Cr ₂ O ₃ -Al ₂ O ₃ -ZSM-5 catalysts for C ₅₊ hydrocarbons in the formation of liquid hydrocarbons with an acceptable aromatic hydrocarbon content, not exceeding 42% wt. C ₅₊ fractions in the amount of hydrocarbons formed; low hydrocarbon yields ranging from 16.2 to 42.8% (per carbon).

Close to the present invention is a method for producing a mixture of C ₁ -C ₁₁ hydrocarbons from synthesis gas, in which the C ₅₊ fraction is enriched in isoparaffins, mainly isopentane and isohexanes [5]. According to this method, BFK is used to convert synthesis gas, the particles of which include two components: crystalline aluminosilicate of the pentasil type with SiO ₂ / Al ₂ O ₃ = 25-100 with a content of sodium oxide of 0.2-0.5 mol%. and rare earth oxides of 0.1-5 mol%, as well as the zinc-chromium component active in methanol synthesis with an atomic ratio of Zn / Zn + Cr from 1: 9 to 1: 1. The use of this catalyst, subject to the recommended parameters for the specified method (pressure 6-15 MPa, temperature 330-400 ° C, space velocity of the feed (synthesis gas) 50-11000 h ^-1 ) allows you to get mainly hydrocarbons With ₅₊ with a low content of the sum of olefins and aromatic hydrocarbons (6.0-13.0 mol%) and with a high content of isopentane and isohexanes (up to 64.4 mol%).

The main disadvantage of the known method of using BFK conversion of synthesis gas is the high residual content of sodium oxide 0.2-0.5 mol%, which reduces the acid function of the zeolite component of BFK, and the use of rare-earth oxides to modify the zeolite complicates the preparation of BFK and, ultimately as a result, increases its value. The high residual content of sodium oxide leads (according to the authors of the method) to a high content of isopentane and isohexanes in the C ₅₊ hydrocarbon fraction (up to 64.4 mol%), which allows the obtained gasoline fraction to be used only as a source of isopentane and isohexanes, and not commercial gasoline.

Close to the present invention is a method for producing p-xylene from a mixture of toluene and synthesis gas by contacting the feedstock in the gas phase with a catalyst containing crystalline aluminosilicate and a metal oxide component at elevated temperature and overpressure [6]. As a crystalline aluminosilicate, a ZSM-5 type zeolite modified with silicon compounds (1-3% wt.) And magnesium (4-15% wt.), And a metal oxide component containing (% wt.): 65-70% ZnO, are used: 29-34% Cr ₂ O ₃ and 1% W ₂ O ₅ , with a weight ratio of zeolite and metal oxide component in the catalyst from 30/70 to 70/30. The process is carried out at a temperature of 380-440 ° C, a weight feed rate of toluene of 1-3 h ^-1 and a volume flow rate of synthesis gas of 1000-10000 h ^-1 in a flow-circulation system with cooling of the gas stream after the reactor, separation of the condensed reaction products and feeding part of the gas stream for recycling.

The main disadvantage of the known method of using BFC in the alkylation of toluene with synthesis gas is the use of a zeolite component of the type ZSM-5, modified with silicon compounds (1-3% wt.) And magnesium (4-15% wt.), Which reduce the activity of BFC in the synthesis synthesis gas into hydrocarbons of the gasoline fraction. Therefore, the maximum degree of CO conversion is 68% at an average temperature in the reactor of 400 ° C. The toluene conversion does not exceed 25%, and the main products of toluene alkylation with synthesis gas are xylenes with a high paraisomer content.

The closest to the invention according to the set of essential features is a method for the conversion of synthesis gas to aromatic hydrocarbons [7], which can be proposed as a prototype of the proposed method for the preparation of universal BFK for converting synthesis gas and hydrocarbons into gasoline fractions. The known method describes a procedure for preparing a catalytic composition containing a (crystalline aluminosilicate) zeolite component with a molar ratio of SiO ₂ / Al ₂ O ₃ > 12 (mainly ZSM-5) and a methanol synthesis catalyst comprising zinc and chromium oxides or zinc oxides, chromium and aluminum with an atomic ratio of Zn / Cr <4.

The procedure for preparing the catalyst in the known method for converting synthesis gas to aromatic hydrocarbons involves separate grinding to particle sizes <0.2 mm of the components of the metal oxide catalyst for the synthesis of methanol, namely zinc and chromium oxides or zinc, chromium and aluminum oxides with an atomic ratio of Zn / Cr < 4, and a zeolite component with a molar ratio of SiO ₂ / Al ₂ O ₃ > 12, having micropores with a size> 0.5 nm, mixing the milled components of the metal oxide catalyst for methanol synthesis and the zeolite component to obtain a homogeneous mixture si, adding alumina to the mixture as a binder, granulating the resulting mixture by tabletting or extrusion, drying the prepared tablets or extrudates in air, then crushing the latter to form granules of the catalyst composition and calcining them.

An improved version of the preparation of the catalyst in the prototype is as follows:

- the catalytic composition contains optimally from 20 to 60% wt. aluminum oxide, which according to [7] corresponds to the maximum selectivity for aromatic hydrocarbons in the conversion of synthesis gas;

- the content of the zeolite component in the catalyst composition is less than the content of the methanol synthesis catalyst in it;

- individual catalyst components (zeolite and oxides of zinc, chromium and aluminum) have a particle size <0.1 mm before the mixing and granulation procedure.

An improved version of the preparation of the catalyst in the prototype [7] is illustrated by the following example of its implementation. Separate grinding of the metal oxide (ZnO-Cr ₂ O ₃ -Al ₂ O ₃ ) and zeolite (HZSM-5) components to a particle size <0.1 mm followed by mixing is carried out. After this, granulation of the resulting mixture is carried out with the formation of catalyst particles with a size of 0.5-2.0 mm The finished catalyst composition has a composition (% wt.): 16% ZnO, 44% Cr ₂ O ₃ , 30% Al ₂ O ₃ and 10% ZSM-5. The experiments are carried out in a reactor with a fixed catalyst bed.

When converting synthesis gas (H ₂ / CO = 1) on the composition catalyst obtained in accordance with the above items (wt%): 16% ZnO, 44% Cr ₂ O ₃ , 30% Al ₂ O ₃ and 10% ZSM- 5 under conditions of a pressure of 8.4 MPa and a temperature of 427 ° C, the content of aromatic hydrocarbons reaches 70.1% by weight. of the amount of hydrocarbons obtained (97% wt. in terms of the C ₅₊ hydrocarbon fraction), which is an improved method for the conversion of synthesis gas to aromatic hydrocarbons (compared with the methods known at that time).

The disadvantages of the selected prototype [7], in terms of component composition and the preparation of the catalytic composition, may include:

- a high content (from 20 to 60% wt.) of Al ₂ O ₃ , which reduces the proportion of the ZnO component in the catalytic composition responsible for methanol synthesis;

- low content in the catalytic composition of the zeolite component, which is the conversion of methanol to gasoline (C ₅₊ hydrocarbons);

- the duration of calcination in air at a temperature of 538 ° C at the final stage of preparation of the methanol synthesis catalyst. From literature [8] it is known that an increase in the temperature of calcination in air of various zinc-chromium methanol synthesis catalysts above 400 ° C leads to their sintering, i.e. to reduce the surface size of the calcined catalysts. For example, increasing the calcination temperature from 400 to 500 ° C reduces the surface value of the zinc chromium catalyst after calcination from 176 to 30 m ² / g.

Due to the above disadvantages of the prototype [7] in terms of component composition and preparation of a bifunctional catalyst composition, as well as other reasons, for example, low atomic Zn / Cr ratio in the catalyst during synthesis gas conversion, the following factors occur:

- high formation of aromatic hydrocarbons (up to 97% wt. in terms of the C ₅₊ hydrocarbon fraction), which significantly exceeds the permissible values for environmental gasolines Euro-4, Euro-5 and Euro-6;

- low selectivity of catalysts for C ₅₊ hydrocarbons in the formation of liquid hydrocarbons with an acceptable content of aromatic hydrocarbons, not exceeding 42% wt. C ₅₊ fractions in the amount of hydrocarbons formed;

- low hydrocarbon yields ranging from 16.2 to 42.8% (per carbon).

The objective of the present invention is to obtain a technical result, which consists in the development of a method for preparing a durable and active universal BFK for converting synthesis gas and hydrocarbons into gasoline fractions with a moderate content (15-35% wt.) Of aromatic hydrocarbons, as well as the possibility of effective use of this universal BFK for the processes of alkylation of aromatic hydrocarbons with synthesis gas, methylation of liquid olefins with products of conversion of synthesis gas, gas oligomerization know olefins and aromatization of liquid n-paraffins in the environment of synthesis gas.

The problem is solved and the technical result is achieved due to the fact that in the method of preparing a universal BFK for converting synthesis gas and hydrocarbons into gasoline fractions, which includes separate grinding of the components of the metal oxide catalyst for the synthesis of methanol, namely zinc and chromium oxides or zinc, chromium and aluminum oxides with an atomic ratio Zn / Cr less than 4, and a zeolite component having a molar ratio SiO ₂ / Al ₂ O ₃ more than 12, having micropores with a size of more than 0.5 nm, mixing of milled metal oxide catalyst components the intesa of methanol and the zeolite component to obtain a homogeneous mixture, adding alumina as a binder component to the mixture, granulating the resulting mixture by extrusion, drying the manufactured extrudates in air, crushing the extrudates to form granules of the catalyst composition and calcining the latter, take the reduced metal oxide catalyst for methanol synthesis with the content of sodium and iron oxides less than 0.04% wt. each, which has a 100% degree of reduction and has not been exposed to temperatures of more than 400 ° C in an air, reducing or inert atmosphere, and an acid component with a sodium oxide content of less than 0.04% by weight, selected from a number of zeolites with a ZSM-structure 5, ZSM-12, Beta, having a molar ratio of SiO ₂ / Al ₂ O _{3 of} more than 25, or from a number of crystalline silicoaluminophosphates with the SAPO-5 structure, or a combination of SAPO-5 with a zeolite of the ZSM-5 type, grind them to a particle size less than 0.3 mm, added to the resulting homogeneous mixture as a binder component ak Willow hydrogel of aluminum oxide or amorphous aluminum hydroxide and, if necessary, chemically purified water with pH = 6.5-7.5, while in the reduced metal oxide catalyst for methanol synthesis, in the acid and binder components there should be no water-soluble metal cations and anions of inorganic and organic acids, and the pH of the components of the bifunctional catalyst should be in the range of 6.5-7.5, after which the paste-like mass obtained by mixing the particles of the reduced metal oxide an inducer of the synthesis of methanol, acid and binder components at a temperature of 20-60 ° C, is passed at least 2 times through a device for grinding materials, in which the cutting unit consists of a rotating figured knife interacting with a fixed grid with through axial channels, and then subjected to screw or piston extrusion at a temperature of 20-60 ° C, and drying the obtained extrudates is carried out in two stages: first at room temperature for at least 24 hours, and then at a temperature of 120 ° C for not m less than 4 hours, while the granules formed as a result of crushing the dried extrudates should have a cylindrical shape with a diameter of 3-5 and a length of 8-12 mm, and the granules produced are calcined after they are loaded into the synthesis gas conversion reactor with a fixed catalyst layer: initially - at a temperature of 200-320 ° C in a nitrogen environment, and then at a temperature of 320-400 ° C in a circulating synthesis gas medium, while the multiplicity of the synthesis gas circulation should be at least 10. In a particular case, a binder component is used active gi aluminum oxide drills - pseudoboehmite, or thermochemically activated aluminum hydroxide, or reprecipitated aluminum hydroxide with a content of sodium, potassium and calcium oxides of less than 0.03% wt. each based on the dry weight of the binder component. In another particular case, the content of the binder component in the universal BFK, based on dry Al ₂ O ₃ , is from 10 to 20% wt. In the following particular case, the reduced metal oxide catalyst for the synthesis of methanol contains tungsten in an amount of not more than 1% wt. As a promoting additive. In another particular case, a zeolite with a ZSM-5 structure, which is part of a universal BFK, contains iron in an amount of from 0.1 to 1% by weight, which is introduced into the crystalline structure of the zeolite at the stage of geothermal synthesis. In the last particular case, the cylindrical granules after calcination are crushed, and then subjected to run-in in a drum device to form granules of a catalytic composition having a spherical shape with a diameter of 0.1-2.0 mm.

The production of methanol synthesis catalysts includes two main stages: the preparation of the catalyst and its restoration to an active state.

In industry, zinc-chromium catalysts can be prepared by the so-called "dry" and "wet" methods. The preparation of the catalyst mass in any case is accompanied by the interaction of chromic anhydride with zinc oxide: ZnO + CrO ₃ = ZnCrO ₄ .

In the “dry” method, pre-ground zinc oxide and chromic anhydride, taken in a certain ratio, are thoroughly mixed first in dry form, then with moisturizing with distilled water. Into the resulting mixture, up to 1% fine graphite is introduced and tablets are formed, for example, 5 × 5 or 9 × 9 mm.

In the wet method, a solution of chromic anhydride is added to a suspension of zinc oxide. The specified process is carried out in special apparatus-mixers with subsequent separation of water. The resulting paste is successively dried, mixed with graphite and tableted.

The catalyst prepared by the "wet" method is more uniform in chemical composition, has greater porosity and high mechanical strength. The activity of the catalyst prepared by the "wet" method is 10-15% higher than that of the catalyst obtained by the "dry" method.

Zinc-chromium catalyst is also obtained by coprecipitation from nitric salts of zinc and chromium. In the reaction of these salts with ammonium carbonate, basic carbonic salts precipitate. When the precipitate is calcined in a hydrogen atmosphere, the resulting zinc and chromium oxides interact with the formation of zinc chromite. The resulting contact mass, after grinding, is mixed with graphite and tableted. The prepared catalysts have a highly developed inner surface (more than 100 m ² / g), 30-36% less bulk density and higher activity compared to the catalysts obtained by the "dry" method.

The catalyst zinc-chromium synthesis of methanol brand SMS-4 get the so-called "semi-wet" method. Moreover, the specified catalyst can be prepared using equipment designed for production by the "dry" method, i.e. without any significant complication of the technology of the cooking process.

According to technical conditions, unreduced catalyst samples should contain (% wt.): 55 ± 1.5% ZnO, 34 ± 1.0% CrO ₃ , not more than 1.3% graphite, not more than 2.0% hygroscopic water (the rest is crystallization water). Unreduced catalyst is a low-porous substance with a small specific surface area (10-15 m ² / g).

The active form of the zinc-chromium catalyst is formed during its reduction by various reducing gases, for example, hydrogen. The specific surface area of the reduced catalyst is 100-120 m ² / g (manufactured by the "dry" method) and 176-196 m ² / g (manufactured by the "wet" method).

The reduction of the zinc-chromium catalyst is accompanied by a large heat release. Recovery is usually carried out with a slow rise in temperature to 190-210 ° C. If the process is carried out carelessly, spontaneous (in some cases, local) overheating of the catalyst is possible, which lead to a loss of its activity as a result of sintering. When the catalyst is reduced with carbon monoxide, the recovery rate is slowed down by the carbon dioxide released. When restored by hydrogen, the inhibitory effect on the process is exerted by water vapor. To reduce the rate of reduction, the reducing gas is diluted with an inert gas (usually nitrogen).

A method for reducing the zinc-chromium catalyst SMS-4 by methanol vapor at a temperature of 170-230 ° C and atmospheric or elevated pressure is proposed. The duration of the recovery is from 8 to 36 hours. When methanol vapor is used as a reducing agent, the risk of overheating of the catalyst is reduced; moreover, the recovery process can be carried out without circulation compressors.

Regardless of the method for producing the methanol synthesis catalyst (“dry”, “wet” or “semi-wet”), the degree of reduction of the zinc-chromium component of the bifunctional catalyst in the present invention should be 100%, i.e. the aqueous extract from the powder of the reduced methanol synthesis catalyst should not contain hexavalent chromium ions.

The acid component of BFK is an oxide system of a crystalline structure. Their structural elements are silicon and aluminum-oxygen tetrahedra, which are interconnected into a continuous crystalline framework. Given that aluminum is trivalent, but has four bonds in the crystal lattice, such a fragment acquires a partial negative charge compensated by the cation, which is most often used as sodium, potassium, calcium, barium, rare earth metals and a hydrogen proton. The tetrahedra, connecting with each other, form cuboctahedra (the so-called sodalite cells), from which, in turn, elementary zeolite cells are built up, making up its crystalline framework with a system of micropores (channels) of molecular size.

The present invention also uses another acidic component of BFK - silicoaluminophosphate type SAPO-5. Crystalline microporous silicoaluminophosphates have a three-dimensional microporous crystalline structure consisting of vertex-bound tetrahedra PO _4/2 , AlO _4/2 and SiO _4/2 . There are a fairly large number of different microporous silicoaluminophosphate structures. Crystalline silicoaluminophosphates are usually denoted by the term SAPO, and each of the various crystalline structures has its own number.

Acid components (zeolites) are synthesized under hydrothermal conditions at a temperature of 130-200 ° C in an alkaline medium in the presence of Na ⁺ , K ⁺ cations with a crystallization duration of 2 to 20 hours. After crystallization, they are subjected to special chemical treatment [9].

The procedure for preparing the acidic component of BFK (zeolite type pentasil with a structure of ZSM-5) is as follows. To silica (30.9% by weight of SiO ₂ , 0.4% by weight of Na ₂ O and 68.7% by weight of H ₂ O) 10N aqueous NaOH solution, n-butanol, 0.1 M Al solution are added successively with stirring ₂ (SO ₄ ) ₃ , the seed and the required amount of chemically purified (demineralized) water (HOV). The mixture is homogenized and crystallized in an autoclave for 4-6 hours at a temperature of 170 ° C. The obtained crystalline product is filtered off, washed with OWL, treated with 0.1N H ₂ SO ₄ at 95 ° C for 3 hours, washed with OWD to a neutral pH value of ~ 7, and then treated with a solution of rare-earth salts or sulfonic acids, washed again with HOV to a neutral pH value (~ 7) and a residual content of sodium oxide <0.04 wt.%, dried at a temperature of 110 ° C.

One of the conditions for achieving the effect of bifunctionality is the creation of a high degree of BFK homogeneity at which the diffusion rate of the intermediate methanol formed on the Zn-Cr component to the surface of the acid component is much higher than the rate of methanol decomposition reaction to CO and H ₂ . The degree of homogeneity of BFK depends on the efficiency of grinding and mixing of its components.

Modern methods of grinding and mixing make it possible to create universal BFKs with a high degree of grinding and homogeneity of its active components: the Zn-Cr component and the acid component. For example, in a ball mill, solid material can be crushed to a particle size of 50 μm, i.e. about 1 thousand particles will be in 1 cm ^{3 of the} obtained powder, which are separate active components of BFK. In this case, the observed efficiency of the bifunctional action of the catalyst will be determined both by the rate of the chemical process and the diffusion rate of the reacting substances between 20 thousand particles. In particular, methanol intermediate formed on the particles of the Zn-Cr component of BFK under the working conditions of methanol synthesis will diffuse to the particles of the acid component for its further conversion on the surface of the acid component to dimethyl ether and then to hydrocarbons.

Universal BFK can be obtained by two main methods: tableting and granulation. The essence of the tabletting method is that under the influence of external pressure, the initial volume of the powdery material decreases (in this case, a mixture of finely ground powders of a reduced catalyst for the synthesis of methanol and zeolite) and the particles of mixed components coalesce to form BFC tablets. The quality of the tablets, their porous structure and strength depend on the pressure value. With increasing pressure to a known limit, in all cases there is a decrease in porosity and an increase in tablet strength, but at the same time, internal stresses acting in the opposite direction also increase. Therefore, there is some optimal pressing pressure, providing sufficient strength and durability, as well as a good presentation of the tablets.

In laboratory conditions, tableting is usually carried out using a manual oil press or laboratory tablet machine. In industrial production, rotary tablet machines are most commonly used.

When using a manual oil press, experts note the main significant drawback - the adhesion of the pressed mixture (charge) to the walls of the mold, which leads to the difficulty of removing the tablet from the mold.

The principle of operation of rotary tablet machines is as follows. Several sets of press tools are located on the periphery of the rotor. During its continuous rotation, special pushers with punches fixed in them sequentially interact with stationary copiers and rollers, which causes specified spatial movements of these organs. In certain areas, pelletized material is introduced into the matrices installed in the rotor, and the manufactured tablets are ejected from the matrices and sent to the collection tank using the baffle plate. Thus, in rotary tablet machines, the continuous transport movement of the processing object is combined with the execution of technological cycle operations. Due to the specified quality, rotary tablet machines have high productivity, which leads to their widespread use in the mass production of tablets.

A significant drawback of the tabletting method by pressing is the rapid wear of expensive dies and punches. In order to reduce the wear of the latter, as well as to reduce the pressing pressure necessary to achieve a given tablet strength, special additives are introduced into the charge, which play the role of a lubricant and thereby reduce the friction of particles of bulk material against each other and against the walls of the mold.

The simplest lubricant is water, which can significantly alter tableting. At low humidity, the bulk material may not pelletize at all and, due to the influence of electrostatic repulsive forces, partially “hang” in the air when filling the charge into the matrix. Too high humidity of the bulk material leads to a loss of strength of the manufactured tablets. More effective lubricant is graphite, which has a noticeable effect on tableting when introduced into the mixture in an amount of about 1% wt.

In the present invention, granulation methods based on the extrusion of pasty masses using a binder component are more widely used both on a laboratory and semi-industrial scale. The properties of the binder component play a very important role in the preparation of the catalysts; therefore, the substance used as the binder component has a number of requirements, of which the following are the main ones: a) the chemical composition of the binder component should not impair the catalytic properties of BFK; b) the binder component should largely determine the strength of the obtained granules of BFK; c) the binder component must have sufficient “bonding” ability so that the strong granules can be obtained using a small amount of the binder component, avoiding the formation of a new porous structure.

Aluminum oxide / hydroxide is used as a binder component, in particular, active aluminum oxide hydrogels: pseudoboehmite, thermochemically activated aluminum hydroxide (TXA) or amorphous redeposited aluminum hydroxide (PHA) with a content of sodium, potassium and calcium oxides <0.03% wt. . each on a dry mass.

Below are some methods for obtaining the binder component of BFK - pseudoboehmite or PHA from sodium aluminate, salt solutions, hydrargillite or TXA.

A) An aqueous solution of sodium aluminate with a molar ratio of Al ₂ O ₃ / Na ₂ O = 0.5 and a concentration of Al ₂ O ₃ - 1% wt. mixed with 100% hydrogen peroxide at a temperature of 0 ° C. The molar ratio of sodium aluminate to hydrogen peroxide based on alumina (Al ₂ O ₃ / H ₂ O ₂ ) is 0.02. The resulting pseudoboehmite is separated on the filter from the mother liquor, washed with distilled (condensate) water at a temperature of 0 ° C to pH = 8 and dried at a temperature of 100 ° C. Thus obtained pseudoboehmite has the following characteristics: density, kg / m ³ - 3010, phase purity,% - 100, specific surface area, m ² / g - 280. The output of pseudoboehmite (per cycle from theoretically possible) is (% wt. Al ₂ O ₃ ) - 73% [10].

B) During the rapid precipitation of aluminum hydroxide from salt solutions, a gelatinous precipitate is formed - aluminum gel, which does not have a crystalline structure, contains a large amount of water and has a high chemical activity.

B) Aluminum hydroxide of a pseudoboehmite structure is obtained by reprecipitation of hydrargillite or by hydrothermal treatment of the thermal dispersion product of hydrargillite.

D) TXA is diluted with HOB and mixed thoroughly. In the colloidal solution thus obtained (pH = 5), a 25% solution of NH _{3 is} added in order to increase the pH to 7.0-7.5. The resulting suspension of aluminum hydroxide is filtered through a vacuum filter, the residual mass is poured with HOV (1:10) and settled for 12 hours, the precipitate is decanted and again filled with HOV. After the next decantation, the resulting mass contains up to 85% wt. H ₂ O. The PHA precipitate is dried in air to a minimum residual moisture content of ≥ 20-30% wt. for use as a binder component of BFK.

In the preparation of many catalysts, especially zeolite-containing, using a binder based on a hydrogel of aluminum oxide, a solution of nitric acid is used as a peptizer. The following are examples of adding acids to the binder component in order to improve the rheological properties of the mass before it is extruded.

According to [11], in a PHA having a moisture content of 65%, zeolite powder is added with stirring at the rate of 20% wt. dry aluminum oxide to 80% wt. dry zeolite. A 65% nitric acid solution is added to the resulting wet mixture at the rate of 5% acid on dry alumina. Then, the paste moisture is adjusted to ~ 35%, and then, after mixing the components to a homogeneous mass, the catalyst is molded by extrusion.

According to [12], a product of processing aluminum hydroxide of a pseudoboehmite structure with nitric acid to a mixture pH ≥ 3.5 is used as a binder.

According to [13], the use of a pseudoboehmite structure as an aluminum hydroxide, with the addition of acids from the number of nitric, hydrochloric, orthophosphoric to a pH of 2–4, allows one to obtain a catalyst with high strength with the introduction of zeolite in the amount of 70-80% wt.

According to [14], aluminum hydroxide (with a humidity of 80%) is loaded into the kneading machine, and the calculated amounts of boric acid (which decomposes into boron oxide B ₂ O ₃ ), zeolite ZSM-12, obtained as a result of double decationation, are added with constant stirring , and cobalt nitrate - Co (NO ₃ ) ₂ ⋅ 6H ₂ O. Stirring is carried out for 0.5 h, after which the resulting catalyst mass with continuous stirring is peptized with a solution of 60% nitric acid. Stirring the resulting catalyst mass is carried out for 0.5-1.0 hours, after which the excess moisture is evaporated in a kneading machine without stopping stirring, and then extruded into cylindrical granules with a diameter of 1-2 mm.

The essence of plasticization (peptization) using pseudoboehmite as an example is the breaking of rigid polymer fibers of a three-dimensional structure into short sections freely moving relative to each other. The introduction of acid into pseudoboehmite leads to the substitution of hydroxyl groups responsible for the orientation and articulation of the polymer chain units. A homogeneous plastic and mobile pulp is formed, which is fed into mixing with the catalytic mass. The result is a paste with high rheological properties.

The authors of the present invention experimentally established that the creation of an acidic environment in the components of BFK before or during their mixing with each other at any stage of its preparation by tabletting or extrusion is unacceptable due to the destruction of the Zn-Cr component with the subsequent migration of metal ions into the zeolite component of BFK . As a result of this, depending on the amount of acid added, a complete or partial loss of the catalytic activity of BFK will occur. An acidic medium can be created by peptization with acid of a paste-like mass of BFK at the stage of “wet” mixing of the components, as well as by introducing the acid together with the acid component or binder component during their mixing with the Zn-Cr component of BFK. The mentioned procedures are unacceptable, because they lead to complete deactivation of BFK.

A similar negative effect on the activity of BFK is exerted by the alkaline medium upon contact of the catalyst components in moistened powders or pasty masses during their mixing at the stage of extrusion or tabletting.

It is necessary to monitor the acidity and alkaline properties of the working fluids of the BFK components, as well as the HOW added to the mixture of components to create a pasty mass of BFK. If possible, the used CW should be neutral (pH = 7) and not contain impurities of salts, acids and alkalis. All equipment for the preparation of BFK, especially the mixer and the extruder, must be thoroughly cleaned of foreign solids before work, washed with a neutral CVD and dried. In laboratory conditions, it is advisable to use freshly prepared distilled water.

The pH values of the working environment of the wet components, CWS, pasty mass of BFK or aqueous extract from the dry fine powder of each of its components should be in the range of 6.5-7.5.

The high content (0.1% wt. And above) of alkali and alkaline earth metal oxides in the acidic component of BFK has a negative effect on the course of hydrogen redistribution reactions with the formation of aromatic hydrocarbons. Some patents use zeolites with a high residual sodium content or the initial sodium forms of zeolites to produce liquid hydrocarbons with a low content of aromatic hydrocarbons. For example, in the above analogue [5], BFK is used to convert synthesis gas, the particles of which include two components: crystalline aluminosilicate of the pentasil type with SiO ₂ / Al ₂ O ₃ = 25-100 with a sodium oxide content of 0.2-0.5 % mol. and rare earth oxides of 0.1-5 mol%, as well as the zinc-chromium component active in methanol synthesis with an atomic ratio of Zn / Zn + Cr from 1: 9 to 1: 1. The use of this catalyst under recommended conditions (pressure of 6-15 MPa, temperature of 330-400 ° C, bulk feed rate of 50-11000 h ^-1 ) makes it possible to obtain mainly C ₅₊ hydrocarbons with a low content of olefins and aromatic hydrocarbons ( 6.0-13.0 mol%) and with a high content of isopentane and isohexanes (up to 64.4 mol%).

For comparison, in the known method [5], crystalline aluminosilicate of the pentasil type with SiO ₂ / Al ₂ O ₃ = 25 with a sodium oxide content <0.02 mol% was used in the mixed catalyst under the same conditions. without oxides of rare earth elements and as a result received 29.5 mol%. the amount of olefins and aromatic hydrocarbons in the composition of C ₅₊ hydrocarbons.

In the present invention, the content of oxides of alkali and alkaline earth metals is limited both in the acid component and in other components of the universal BFK and should not exceed 0.04% wt.

The present invention experimentally established that the suppression of aromatization reactions in the process of converting synthesis gas to liquid hydrocarbons, processes of alkylation of aromatic hydrocarbons with synthesis gas, methylation of liquid olefins with products of conversion of synthesis gas, oligomerization of gaseous olefins and aromatization of liquid n-paraffins in a synthesis environment water-soluble metal cations (Ca ²⁺ , Mg ²⁺ , Zn ²⁺ , Cr ³⁺ , Fe ³⁺ , Cu ²⁺ , etc.) also cause gas through their ion exchange with acidic centers of crystalline aluminosilicates (zeol Itov) and silicoaluminophosphates. For this reason, in the acid component, in the reduced methanol synthesis catalyst, and in aluminum oxide / hydroxide, which are used in the present invention for the preparation of universal BFC, there must be no water-soluble metal cations, as well as anions of inorganic and organic acids.

Also, in the present invention, it was experimentally established that the iron introduced into the zeolite at the stage of hydrothermal synthesis, is part of the active centers and accelerates the reaction of burning catalyst coke, which leads to lower temperatures and shorten the burning time of coke. Therefore, in the composition of the zeolite type ZSM-5 BFK enter iron in an amount of from 0.1 to 1% wt. [fifteen]. At the stage of zeolite synthesis, iron is introduced in the form of iron sulfate [16].

To obtain liquid hydrocarbons with a high content of C ₁₀₊ methylaromatic hydrocarbons, wide-porous zeolites (zeolite of the ZSM-12 type, zeolite Beta, etc.) or silicoaluminophosphate with the SAPO-5 structure or its combination with zeolite of the ZSM-5 type are used. The sizes of micropores (channels) of wide-porous silicate and phosphate systems allow the synthesis of polymethyl and ethyl aromatic hydrocarbons C ₉₊ from CO and H ₂ to proceed without steric restrictions (see table 1).

In the present invention, the amount of binder component (pseudoboehmite, TXA or PHA) added to the mixture of active components (fine powders of a reduced methanol synthesis catalyst and an acid component) is strictly limited. It is necessary to carefully monitor that BFK contains only 10-20% wt. hydrated alumina (based on dry Al ₂ O ₃ ). The specified content of Al ₂ O _{3 is} significantly lower compared to the prototype [7], in which the claimed catalysts contain from 20 to 60% wt. Al ₂ O ₃ , as well as with other analogues. For example, in [17]) the components of the catalyst consist in a mass ratio (calculated on a dry carrier): aluminosilicate / pentasil / pseudoboehmite = 5-15 / 45-60 / 35-40.

The results of experiments using BFK in the process of producing liquid hydrocarbons from synthesis gas show that with an increase in the content of the binder component, the activity of BFK decreases, therefore, the minimum content of the binder component in it was determined experimentally (10% wt. Based on dry Al ₂ O ₃ ), in which an acceptable plasticity of the paste mass can be achieved without disrupting the extrusion process. Moreover, the strength of the obtained granules BFK was quite satisfactory.

The present invention also defines the upper limit of the content of aluminum hydroxide in BFK (20% wt. Based on dry Al ₂ O ₃ ), above which a noticeable decrease in the activity of universal BFK during the conversion of synthesis gas to liquid hydrocarbons and in other processes using synthesis gas.

Formability of pasty materials containing 30-80% wt. solid phase, based on the ability of materials under the influence of mechanical influences to change their physical and mechanical properties, as a result of which the mass gains the ability to acquire and maintain the shape attached to it. This property is due to the content in the mass of the thixotropic colloidal fraction, which under the influence of mechanical action reduces its plastic strength and restores it after removing this effect.

In the process of further processing of the formed granules, after the dispersion medium is removed, the solid particles form a rigid framework, and the particles of the colloidal fraction form coagulation or crystallization bonds with each other and with the surface of the particles of the solid phase of the main component of the moldable mass, combining the whole mass into a single system and thereby "Binder".

In the present invention, the reduction in the content of BFK to 10% wt. hydrated alumina (based on dry Al ₂ O ₃ ) is offset by the use of a hot mixing process. It was experimentally established that in the temperature range of 20-60 ° C (preferably at a temperature of 40-60 ° C) with prolonged stirring it is possible to obtain a sufficiently plastic paste-like mass, which should be immediately extruded in a hot state, since this mass loses moisture when cooled and plasticity. The plastic paste-like mass prepared in the mixer is molded at a temperature of 20-60 ° C (preferably at a temperature of 40-60 ° C), passing it through special durable dies to obtain universal BFK granules with a diameter of ≥ 5 mm.

The process of hot mixing of the wet components of BFK should continue for ≥ 20 min. The duration of mixing and the beginning of the extrusion is determined based on the uniform distribution of the binder, the water required for molding, the temperature of the paste and its plasticity. During mixing and extrusion of the hot pasty mass, partial evaporation of water occurs over time, therefore it is necessary to maintain the paste moisture required for molding. Otherwise, with a decrease in the thixotropic and rheological properties of the paste, there may be a loss of its ability to flow and force through the die. There will be a situation in which the pressure on the paste-like mass near the die increases so that a “plug” of paste with a higher density and low humidity can form in front of the die. In this case, the extrusion process will cease, there will be a need to stop the apparatus and remove the “plug” in order to avoid failure of the die.

In the present invention, it was experimentally established that the wet paste-like mass of BFC (i.e., the initial, but not sufficiently plastic paste) before the molding procedure, it is advisable to pass, at least 2 times, through a device for grinding materials, similar to the device of a meat grinder, in which the block consists of a rotating figured knife interacting with a fixed lattice with through axial channels of a round or other shape. As a result of the aforementioned mechanical treatment, a homogeneous and plastic mass of BFK with optimal or close to it (1-3% less) humidity will be obtained.

Literary sources describe cases in which it is advisable to use molding materials with an moisture content below the optimum value for extrusion. Examples include hydrogel systems based on aluminum, zinc oxide, obtained from basic zinc carbonate. At the optimum value of molding moisture, these masses have excessive ductility, which in the end does not allow to form high-quality products from them. A decrease in humidity reduces the proportion of plastic deformations in the overall balance in favor of fast elastic deformations, which ensures approximately uniform development of all types of deformations. However, the mentioned technological technique is possible only in some cases, and the range of variation in humidity is very limited (± 2% wt.) [18].

There are various examples of mechanical effects on the rheological properties of clay materials, which can improve the formability of clay pastes, transfer them from one structural-mechanical type to another.

The use in the present invention of a device for grinding materials as a means of mechanical action on the wet mass of BFK before its formation allows to obtain a homogeneous and plastic mass, and the quality is better than when using conventional mixers. It should be noted that in the patent and scientific and technical literature the authors did not come across examples of the similar use of devices for grinding materials as applied to the process of preparing bifunctional or other zeolite-based catalysts.

In the scientific and technical literature [19], the influence of the intensity of the mechanical processing of wet paste on the porous structure of the finished product was studied. With increasing intensity of the machining, the volume of large pores decreases, while, accordingly, the strength of the granules increases. A study of wet pastes before molding found that during the machining process there is a more or less strong grinding of the initial skeleton, i.e. its destruction. The result is a denser packing of the mass and a decrease in the volume of macropores.

An obligatory stage of the process of preparing catalyst systems based on precipitation and gels obtained by various methods is drying. At this stage, the formation of texture and other physical properties of the catalysts occurs; therefore, drying plays an important role in the process of their preparation.

The effect of drying conditions on the texture of BFK depends on a number of factors, including: drying method; the water content in the catalyst before drying; temperature and rate of removal of water from the granules of the catalyst; the nature of the components of BFK and their ratio in the catalyst.

According to researchers, the drying process of catalysts obtained by extrusion using an active hydrogel of aluminum oxide proceeds in three stages. At the first stage, when the liquid is removed only from the outer surface of the BFK granule, there is a decrease in the radii of curvature of the menisci of the liquid, causing the most significant shrinkage. It is at this stage that the pore volume of the catalyst is mainly formed. In the second stage of drying, the evaporation front moves into the grain volume before the intensive destruction of the solvate shells begins. The second stage of drying can significantly affect the size distribution of the pore in the catalyst. The most important stage for the formation of the catalyst structure is the third stage, during which the intensive destruction of the solvate shells occurs. Moreover, at all three stages of drying, the contacts between the particles of the BFK components are overgrown [20].

Drying of BFK granules in air (the preparation of catalysts is often referred to as “drying”) is usually carried out at a temperature of 20 ° C for ≥ 24 h, and then in an oven at a temperature of 120 ° C for ≥ 4 h The drying of BFK granules at a temperature of 120 ° C is accompanied by the loss of only physical water without destroying the structure of the binder component (for example, pseudoboehmite).

It was found that with an increase in the temperature of calcination of aluminum hydroxide, the strength characteristics of the granules of the absorber or catalyst significantly increase [21].

By analogy with the above, in the present invention, during the start-up of reactors for converting synthesis gas to liquid hydrocarbons, the granules of universal BFK are calcined: initially in a nitrogen medium at a temperature of 200-320 ° C, and then in a circulating synthesis gas at a temperature of 320-400 ° С and circulation multiplicities ≥ 10. In this case, chemically bound water is removed in the BFK granules and structural transformations of the BFK binder component occur with the formation of boehmite, and at a temperature of 400 ° C the boehmite partially transforms into γ-Al ₂ O ₃ .

The transition of boehmite to γ-Al ₂ O ₃ is completed only at a temperature of 500 ° C, which is an unacceptably high temperature for the Zn-Cr component of BFK, because leads to sintering and a decrease in surface value after calcination at a given temperature [8].

Many of the known granular catalysts have a maximum mechanical crush strength of granules of no more than 3.0 MPa and a minimum strength of about 2.5 MPa. Moreover, almost all oxide catalysts were calcined at high temperatures (at least 500 ° C) before use, transportation to the consumer, or storage, which significantly increased the strength of the catalysts.

In the present invention, the measurement of the mechanical strength of the CFC granules for crushing was carried out after drying at a temperature of 120 ° C for ≥ 4 hours. According to the developed method, the calcination of the CFC granules is carried out in reactors under operating conditions: initially, in a stream of nitrogen at a temperature of 200-320 ° C ; then in a stream of synthesis gas at a temperature of 320-400 ° C in circulation conditions with a circulation ratio of at least 10 (in order to prevent overheating in the catalyst bed). Thus, the strength of the catalyst granules after this “soft” calcination procedure will increase significantly without sintering and reducing the surface area of the catalyst. This circumstance plays an important role in long runs and regeneration of a universal BFK.

It should be noted that the mechanical strength of the universal BFK pellets measured after drying at a temperature of 120 ° C is important exclusively for transporting the catalyst to the consumer and loading it into the reactors.

In the proposed method of preparing a universal BFK for the process of converting synthesis gas to liquid hydrocarbons or processes for the joint conversion of synthesis gas and hydrocarbons using various of the above-mentioned binders, acid components and ratios between all BFK components, as well as when changing the moisture content of the pasty mass and its content a binder component, catalyst granules of various physicochemical properties were obtained.

After 4-hour drying in an oven at a temperature of 120 ° C, the mechanical strength of the obtained BFK granules for crushing along the generatrix was at least 2.0-2.2 MPa, and at most 3.6-3.8 MPa. When conducting studies to optimize conditions and refine the formulation of the preparation of universal BFK, the mechanical strength of the granules by crushing along the generatrix was increased to a minimum value of 2.5 MPa. Compared with other laboratory and industrial catalysts, the mechanical strength of the granules (after drying) obtained by the present invention is quite acceptable. Further, for comparison, the strength characteristics of some industrial catalysts of domestic production are given.

A known method of producing a granular catalyst for the synthesis of formic acid [22], containing 15-20% vanadium oxide and 85-80% titanium oxide. The catalyst has a specific surface area of 15-42 m ² / g and a maximum mechanical crush strength of granules of 2.8 MPa.

The zinc-chromium methanol synthesis catalyst SMS-4 is available in unreduced or reduced form in the form of cylindrical tablets. The reduced catalyst has a minimum tablet crush strength of 2.0 MPa [23].

The STK-05 catalyst is produced in the form of extrudates and has a minimum crushing strength of granules of 2.5 MPa [24].

The ANKM-1T catalyst is produced in the form of extrudates; it has a minimum crush strength of granules of 2.0 MPa [25].

The A-ECG catalyst is produced in the form of extrudates; it has a minimum crush strength of granules of 2.0 MPa [26].

The APS-F zinc-copper catalyst (molded) has a minimum crush strength of the granules of 1.5 MPa [27].

The GKA-75 catalyst is a light yellow extrudate, consisting of active alumina with the addition of kaolin, and has a minimum granular crush strength of 2.5 MPa [28].

A large influence on the penetration depth of particles of one component into the group of particles of another component is exerted by the particle size of the mixture of BFK components. As a result of intensive mixing of the particles of the components, the diffusion process is also enhanced. Naturally, the smaller the particles, the more points of contact between them and the deeper the particles of one component can pass into the group of particles of another component.

For fine grinding of catalyst granules, drum mills or vibratory mills are most often used. In drum mills, when the drum rotates, the balls are carried away by centrifugal force upwards, after which, upon reaching a certain height, they fall onto the wall of the drum.

In vibratory mills, balls under the action of a vibrator make random movements. Typically, in a ball mill, the catalyst granules can be crushed to a value of the order of 50 microns. Thanks to a much larger number of collisions, the vibratory mills allow the grinding of granules much more intensively.

As a result of fine grinding of the solid components of BFK, possible (and actually occur in zeolite of the ZSM-5 type) significant changes in a number of physicochemical properties of the catalysts, in particular, there is a mechanical violation of the crystal structure of the surface layers, their transformation into a quasi-amorphous state. For example, it is known that with fine grinding of quartz, amorphization occurs, which is achieved after 30 minutes of grinding in a vibratory mill.

Based on the results of studies, experts concluded that the maximum grinding of solid materials is achieved with some optimal grinding time. On the contrary, with too long machining, the formation of large, very dense particles occurs, while the dispersion and surface size decrease [29].

A distinctive feature of the present invention, compared with the prototype [7], is the use for the preparation of BFC zinc-chromium component containing as a promoting additive tungsten in an amount of not more than 1% wt. The specified additive improves the catalytic activity of the reduced methanol synthesis catalyst and, accordingly, increases the degree of synthesis gas conversion and hydrocarbon yield, without reducing the selectivity of the formation of a gasoline fraction.

In the proposed method for the preparation of a universal BFK in most examples, screw extruders of the type ПШ-45, ПШ-50 or ГФШ-60 are used, which are the most common in the production of small experimental batches of catalysts (from 30 to 200 l).

At the same time, in the manufacture of laboratory batches of BFK in small quantities (from 1 to 50 l), piston extrusion is used using a laboratory metal syringe (up to 0.5 l) or a 5 l plunger press.

Piston extrusion is widely used in various fields of technology, including non-ferrous metallurgy, the production of certain types of polymeric, composite and ceramic materials, pharmaceuticals, etc. At present, piston machines are the main type of equipment in the production of rods, profiles, tubes and capillaries from some thermosets, fluoroplastics and thermoplastics. Most often, piston machines are used in the processing of low-flow highly friction materials that are difficult to process on screw machines.

Piston extrusion is also used for the production of catalysts, mainly in cases where it is necessary to obtain granules with high mechanical strength, using an insufficiently plastic mass of optimal or low humidity.

Screw machines used in catalytic production usually have a capacity of 30 to 800 kg / h and screw diameters of 60 to 200 mm. They provide granules with a diameter of 1.3 to 17 mm.

Piston screw machines have significantly lower productivity (10-30 kg / h). The pressing force (50-100 t) is provided by the movement of the piston compressing the moldable plastic mass in a closed volume limited by the surface of the cylinder, dies and the end surface of the piston. The diameter of the pistons is 180-220 mm, the die holes are 3-5 mm.

Piston hydraulic machines have a capacity of up to 350 kg / h. With a piston diameter of 120-150 mm, they provide a pressing force of 50-80 tons. The dimensions of piston hydraulic machines are slightly larger than that of screw extruders, due to the need to use a pump unit in their composition.

The main difference between a piston and a screw extruder is that the flow of plastic mass in the piston former is not complicated by any significant axial and radial movement in the flow, which is observed in screw extruders.

The advantages of piston extruders, compared with screw machines of a similar purpose, include: the possibility of extrusion of low-plastic materials, the relative simplicity of the design, the possibility of creating higher pressures in the cylinder, less wear of the working bodies, etc. And the disadvantages are lower performance of piston extruders and the lack of mixing functions (in contrast to screw extruders). Therefore, the working mixture must first be thoroughly homogenized.

To implement the proposed method for the preparation of a universal BFK in a number of examples, piston extrusion was used using a plunger press such as an enlarged model of a laboratory syringe.

The catalyst is molded on a plunger press with a loading volume of 5 l under pressure from 4 to 10 MPa, and the molding pressure is increased as the moisture content of the mass decreases. Extrudates with a diameter of 4 mm are dried in air for 24 hours and dried in an oven at a temperature of 120 ° C for 6 hours. The maximum mechanical strength of the obtained granules for crushing along the generatrix was 6.0 MPa, the minimum strength along the generatrix was at least 3, 0 MPa. In this case, the maximum mechanical strength of the granules for crushing on the end face was 16.7 MPa, and the minimum mechanical strength on the end face was not less than 5.0 MPa.

When using screw extruders of the type ПШ-45, ПШ-50 or ГФШ-60 and in the case of strict observance of the conditions for the preparation of BFK presented in the formula of the present invention, granules of similar BFK were obtained in which the maximum mechanical crushing strength along the generatrix reached 4.0 MPa, and the minimum strength along the generatrix is not less than 2.5 MPa. For comparison, the maximum mechanical strength of granules BFK obtained using screw extrusion, crushing on the end face was 8.0 MPa, and the minimum mechanical strength on the end face was not less than 3.0 MPa.

Thus, the indicators of the mechanical strength of the granules obtained by the piston (plunger) extrusion method were 1.2–2.1 times higher compared to the similar indicators of the strength of granules of the same catalysts made using screw extrusion.

Based on the achieved high indicators of the mechanical strength of the granules for crushing, obtained by the piston (plunger) extrusion method, the present invention proposes a methodology for the production of small-spherical BFK, which consists of 4 successively performed stages:

1) the catalyst is formed on a plunger or piston press with a wet mass loading volume of 5 l or more under a pressure of 4 to 10 MPa or more. Extrudates with a diameter of 4 or 5 mm are dried in air to an air-dry state, dried in an oven at a temperature of 100-150 ° C for 4 to 6 hours;

2) dried in a drying oven or well-sunk extrudates are broken in a special drum device with partitions to obtain BFK granules up to 20 mm long. The granules are calcined in an oven while slowly raising the temperature from room temperature (~ 20 ° C) to a temperature of 400 ° C;

3) granules BFK, calcined at a temperature of 400 ° C for 4 to 6 hours, crushed to obtain fractions or fractions of various sizes of grains of irregular shape: 0.1-0.25 mm, 0.25-0.5 mm, 0 5-1.0 mm or 1.0-2.0 mm;

4) the obtained fractions or a separate fraction of irregularly shaped BFK grains are run in a drum device until spherical grains are formed. During the break-in, larger-grain fractions are obtained from fractions of coarser grains, which are also rolled in a drum. As a result, after a run-in in a drum device, a wide fraction of spherical-shaped grains with a diameter of 0.1 to 2.0 mm can be obtained, depending on the grain size of the starting fractions or a separate fraction taken for rolling. After the fractionation procedure, a working narrow fraction of universal fine-spherical BFK grains is selected for loading into the reactors.

After the successful completion of all four of the above stages, the universal fine-spherical BFC is ready for use in the process of producing high-octane gasoline from synthesis gas or other combined processes for the conversion of synthesis gas and hydrocarbons in reactors with a fluidized (“boiling”) catalyst bed.

From sources of scientific and technical information it is known that granulation of diluted masses can be done by "gas-phase" or "liquid-phase" methods. The first method is used to obtain microspherical particles with a diameter of 35-150 microns (0.035-0.15 mm), the second - mainly for the production of spherical granules with a diameter of 2-4 mm.

A progressive method for producing finely dispersed catalysts is spray drying, which consists in the rapid dewatering of the catalyst suspension due to the difference in the partial vapor pressure of the liquid in the environment and on the surface of the moving droplets of the dried catalyst. The mentioned method produces homogeneous microspherical particles with a diameter of about 100 μm, for example, in the production of aluminosilicate catalysts.

When spray drying, due to its increased speeds and a short residence time of particles in the apparatus, the latter have greater porosity, significantly lower bulk density and strength than when drying the catalyst in a fixed bed. Moreover, the catalyst prepared in a fixed bed is more narrowly porous and substantially more resistant to abrasion [30].

The formation of solid phase granules from a liquid medium can occur when the sol is dispersed into a gaseous (air, flue gas) or liquid medium. Liquid molding, which consists in the fact that the sol (pseudo-sol) of the substance being formed is introduced into a column filled with two immiscible liquids, is better studied and more widely used. The upper layer, in which the formation of the granule actually occurs, consists of liquid hydrocarbons. In the lower part, where the granules solidify, there is an aqueous solution of the coagulator.

The sols used in liquid molding are obtained either by quick mixing of the solutions of the starting materials, or by peptization of the previously prepared and washed precipitate of aluminum hydroxide with hydrochloric or nitric acid (pseudosols). The obtained sol (or pseudo-sol) is dispersed in one way or another in the upper part of the molding column, in which the hydrocarbon layer is located. In the process of moving through a layer of oil under the influence of surface tension at the sol-oil interface, the droplets of the sol (or pseudo-sol) take a spherical shape. The coagulation rate is influenced by the concentration, pH, and temperature of the sol (or pseudo sol). After coagulation, the particles enter the ammonia solution for the syneresis stage.

A ball zeolite-containing catalyst for the conversion of hydrocarbons is obtained from a pseudo-sol of aluminum hydroxide by peptization of a wet mass of hydroxide with an acid, introduction of a zeolite into a pseudo-sol, homogenization of a zeolite-containing pseudo-sol, hydrocarbon-ammonia molding, drying and calcination of granules.

To obtain micro- or small-spherical BFK, this method of liquid molding cannot be applicable due to the contact of the bifunctional catalytic mass with an acidic medium at the stage of peptization or alkaline medium (ammonia solution) at the stage of syneresis.

In the present invention, as described above, receive fine-spherical BFC with a grain diameter (particles) of from 0.1 to 2.0 mm (100-2000 μm), different from microspherical particles with a diameter of 35-150 μm (0.035-0.15 mm ) and spherical granules with a diameter of 2-4 mm. The main difference of the proposed method is the method of preparation of small-spherical BFK, in which liquid media with a pH above or below 6.5-7.5 are not used.

When using universal fine-spherical BFCs in a fluidized bed, their more or less abrasion and dust carry away, causing both a decrease in the amount of catalyst in the contact apparatus and contamination of the reaction products with catalyst dust. Therefore, an extremely important characteristic of catalysts is their abrasion resistance.

The standard MP-8I device is used to determine the abrasion of micro- and small-spherical catalysts and sorbents. It consists of two drums rotating at different speeds. An external lattice drum having blades rotates at a speed of 30-200 rpm and pours granules onto another (inner) drum, the rotation speed of which is 1000-10000 rpm. The crushed material is collected in a pallet. A sample of sample remaining in the trellised drum is a measure of abrasion. The experiments showed that such a technique mainly satisfies the set requirements for determining the abrasion of BFK.

BFK, prepared by the proposed method in the form of granules with a size of 3-5 mm or small-spherical shape with a diameter of grains (particles) from 0.1 to 2.0 mm, are universal and can be used in various chemical processes: the conversion of synthesis gas into liquid hydrocarbons, alkylation of aromatic hydrocarbons with synthesis gas, methylation of liquid olefins with the products of conversion of synthesis gas, oligomerization of gaseous olefins and aromatization of liquid n-paraffins in a synthesis gas medium.

The basic process in which the proposed universal BFK can be effectively applied is the process of converting synthesis gas into liquid hydrocarbons, which can be used as gasoline with a low content of benzene and a moderate content of aromatic hydrocarbons. The feedstock for producing synthesis gas may be natural and associated petroleum gases, coal, biomass, industrial exhaust gases and other carbon-containing raw materials.

The most significant characteristic of this process is the dependence of the composition of the formed liquid hydrocarbons on the composition of the initial synthesis gas. As an example, the drawing shows the influence of the composition of the initial synthesis gas on the distribution of the formed liquid hydrocarbons (bifunctional catalyst Zn-Cr / HZSM-5, pressure 8 MPa, temperature 400 ° C).

The composition of the initial synthesis gas is determined by the molar ratio of hydrogen and carbon oxides, i.e. functional f = (Н ₂ -CO ₂ ) / (СО + CO ₂ ). The drawing shows that with a decrease in the ratio of (H ₂ -CO ₂ ) / (CO + CO ₂ ) in the initial synthesis gas, an increase in the content of aromatic hydrocarbons in the resulting liquid hydrocarbons is noted. For this reason, as the activity of universal BFK decreases, in order to maintain the optimal content of aromatic hydrocarbons in the resulting liquid hydrocarbon fraction, the initial synthesis gas should have: functional f = 2.0-2.5 (at the beginning of the catalyst run); the functional f is close to 2 (in the middle of the path of the catalyst) and the functional f = 1.8-2.0 (at the end of the path of the catalyst).

Universal BFC, prepared by the method described in detail in the present invention, were investigated in the conversion of synthesis gas obtained by mixing various industrial exhaust gases: coke oven and blast furnace gas; reducing and blast furnace gases; flue gases of ferroalloy production and hydrogen.

As a result of the conversion of industrial Н ₂ , СО, CO ₂ - containing exhaust gases at pilot plants in the factory using BFC, liquid hydrocarbons of various compositions were obtained.

In addition, universal BFK, which were prepared by the proposed method described in the present invention, were also investigated in the conversion of synthesis gas diluted with nitrogen from 30 to 50% vol. For example, when converting synthesis gas diluted with nitrogen by 50% vol., At a pressure of 2 to 8 MPa and an average temperature in the reactor of 380-400 ° C under flowing conditions, liquid hydrocarbons containing from 40 to 80% wt. aromatic hydrocarbons. As a result of experiments performed in a laboratory setup, the conversion of carbon monoxide was 96-99%, while the selectivity of the process for liquid hydrocarbons was achieved at the level of 60-80% wt. the amount of hydrocarbons formed.

An important process in which the proposed universal BFKs are used is the process of producing alkyl aromatic compounds by alkylation of aromatic hydrocarbons with synthesis gas, more precisely, intermediate products of the synthesis gas conversion - methanol, dimethyl ether, ethylene and propylene.

Table 2 presents the results of the alkylation of benzene, toluene and o-xylene with synthesis gas on BFK Zn-Cr / HZSM-5, which is the main component of the proposed universal BFK.

From the analysis of the data in Table 2, it follows that benzene, toluene, and o-xylene are easily alkylated with synthesis gas with a conversion of 75-87% to obtain a number of alkyl products with a higher molecular weight than the starting aromatic hydrocarbon. The main alkylation products are methyl and methyl ethyl aromatic hydrocarbons such as toluene, xylenes, ethyl toluenes, ethyl xylenes, trimethylbenzenes (mainly pseudocumene) and tetramethylbenzenes.

The purpose of the process of alkylation of aromatic hydrocarbons with synthesis gas on a universal BFK is to increase the content of C ₇ -C ₁₀ aromatic hydrocarbons in the gasoline fraction to increase its octane number to the values specified in GOSTs for gasoline.

Based on the results of the alkylation of benzene, toluene and o-xylene with synthesis gas on Zn-Cr / HZSM-5 BFK, it can be noted that to increase the octane number of gasoline fractions, it is most preferable to use toluene as a starting material for synthesis gas alkylation. Benzene is only 81% alkylated and the resulting alkylate cannot be used as an octane enhancing additive due to the toxic properties of residual benzene, and o-xylene is the most expensive and scarce raw material compared to benzene and toluene.

In addition to the process of alkylation of aromatic hydrocarbons with synthesis gas, there are a number of processes for the conversion of hydrocarbons of various classes in the synthesis gas medium, which use the proposed universal BFKs, namely, methylation of liquid olefins with methanol followed by dehydration of ethers to iso-olefins, gaseous oligomerization olefins and aromatization of liquid n-paraffins in a synthesis gas medium, as well as processes of conversion of hydrocarbons of natural origin (with a boiling point i <220 ° C), containing paraffins, naphthenes and olefins in various ratios or conversion processes of synthetic liquid hydrocarbons obtained from synthesis gas by the Fischer-Tropsch synthesis method, containing mainly n-olefins, n-paraffins and oxygen-containing compounds . The final products in these processes are hydrocarbon gasoline fractions consisting of a mixture of iso-olefins, iso-paraffins, aromatic hydrocarbons and naphthenes having octane numbers in excess of the octane numbers of the feedstock.

The process of converting liquid and gaseous olefins, taken as feedstock, together with synthesis gas on the proposed universal BFK is of great practical importance. During the processing of hydrocarbon raw materials at domestic oil refineries and chemical plants, various hydrocarbon fractions containing olefins are formed as by-products of a number of processes, which in many cases, unfortunately, do not find qualified use (coking gasoline, thermocracking gasoline, some fractions of thermal and catalytic cracking gases, production of monomers and synthetic rubber, etc.). At the same time, they can be a raw material for the production of liquid motor fuels - gasoline and diesel fractions, which can be produced from hydrocarbon feeds containing C ₂₊ olefins, using methylation of liquid olefins with methanol, followed by dehydration of ethers into iso-olefins and processes oligomerization of gaseous olefins on the proposed universal BFK with subsequent hydrogenation of the obtained liquid fractions to improve their quality, i.e. to increase their stability to oxidation.

Hexene-1 was chosen as a typical normal-structure olefin with an end double bond for conversion in hydrogen-containing gases. A comparison of the indicators of the synthesis of hydrocarbons from CO and H ₂ with the hydroconversion of hexene-1 in hydrogen and synthesis gas at a pressure of 2 MPa, temperatures of 340 ° C and 400 ° C on BFK Zn-Cr / HZSM-5 is shown in table 3.

The features of the influence of temperature and the type of gaseous medium (hydrogen, synthesis gas) on the selectivity of hexene-1 hydrotransformation are as follows:

a) low temperature (340 ° C) and the presence of CO in the gas prevent the flow of hexene-1 hydrocracking to C ₁ -C ₄ hydrocarbons;

b) low temperature (340 ° C) and the transition from hydrogen to synthesis gas contribute to the formation of C ₇₊ hydrocarbons from hexene-1;

c) in a hydrogen medium at a pressure of 2 MPa, aromatic hydrocarbons from hexene-1 on BFK Zn-Cr / HZSM-5 are not formed;

g) during the conversion of hexene-1 in the medium of synthesis gas at a pressure of 2 MPa, aromatic hydrocarbons make up more than 15% wt. from the amount of C ₅₊ hydrocarbons.

Table 3. Hydroconversion of hexene-1 in a medium of hydrogen and synthesis gas (H ₂ / CO = 2.2) at a pressure of 2 MPa, temperatures of 340 ° C and 400 ° C on BFK Zn-Cr / HZSM-5.

The weighted feed rate of hexene-1 0.7 h ^{-1 the} volumetric feed rate of the synthesis gas of 800 h ^-1 .

When comparing the indicators of the processes of hydrocarbon synthesis from CO and H ₂ and hydrotransformation of hexene-1 in synthesis gas at a pressure of 2 MPa, it should be noted (see table 3) that in the presence of hexene-1, the conversion of synthesis gas is significantly higher than the conversion of synthesis gas in the absence of hexene-1. This is due to the fact that at low pressure (2 MPa) the process of synthesis of hydrocarbons from CO and H ₂ on BFK Zn-Cr / HZSM-5 proceeds with a rather low efficiency, namely, the productivity of the process at a pressure of 2 MPa and a temperature of 340 ° C reaches only 3 g of C ₅₊ / l of catalyst / h with a conversion of CO of 18%. The combined supply of hexene-1 and synthesis gas to the reactor intensifies the reactions involving CO and H ₂ , for example, the conversion of CO increases 2.2-2.8 times.

Thus, the conversion of hexene-1 in the presence of synthesis gas allows the methanol formed from synthesis gas to be involved in its interaction with hexene-1 and other olefins with the formation of ethers and their subsequent dehydration with the formation of iso-olefins. As a result, the ongoing processes lead to an increase in the conversion of synthesis gas to methanol on the Zn-Cr component and its consumption in reactions with olefins on the BFK zeolite component. Moreover, at low temperatures (340 ° C), the resulting isoolefins have high resistance to cracking reactions. Under these conditions, gaseous olefins formed from methanol (ethylene, propylene) easily enter into oligomerization reactions on the BFK zeolite component to form liquid iso-olefins.

Based on an analysis of the experimental data obtained during the hydroconversion of hexene-1 in a hydrogen and synthesis gas of various compositions, it was concluded that an increase in the partial pressure of CO suppresses the hydrogenation activity of the Zn-Cr component of the universal BFK, which promotes the formation of iso-olefins and aromatic hydrocarbons from hexene-1.

The effect of carbon oxides on the hydrogenation activity of universal BFKs can be used in the processes of producing high-octane gasoline fractions from various hydrocarbon feedstocks containing olefins, paraffins and naphthenes in various ratios. The conversion of hydrocarbon fractions of natural (gas condensates, straight-run fraction of oil) or synthetic origin (Fischer-Tropsch gasolines) in the synthesis gas medium on the proposed universal BFCs allows increasing the octane number of the obtained gasoline fractions due to the formation of iso-olefins and aromatic hydrocarbons without reducing the yield of the target product.

The interregeneration range of a universal BFK depends on various factors: the content of hydrogen and carbon oxides in the circulating gas, their volumetric ratio, and also the degree of deviation of the operating temperature in the catalyst layer from the optimal value. The surface of the catalyst during run in contact with synthesis gas and its conversion products (olefins, aromatic hydrocarbons) is gradually coated with coke and its precursors, namely highly condensed polyaromatic compounds. In this case, the active centers of the acid component of the catalyst are blocked, the diameter of micro- and macropores is reduced, the mass transfer of reaction products in the catalyst channels is worsened, and, in the case of local overheating on the shelves, the sintering of the catalyst granules is possible and, as a result, the hydraulic resistance of the catalyst layer increases. The coking process of the catalyst leads to a decrease in the selectivity for aromatic hydrocarbons, an increase in the breakdown of unconverted methanol, a decrease in the productivity of the process and the yield of liquid hydrocarbons. To maintain the quality of gasoline and other process indicators at the required level during the run, a gradual increase in the average temperature in the catalyst bed and an increase in the concentration of carbon monoxide in the circulating gas are required.

The established period of active operation of the universal BFK is at least 500 hours of continuous operation under optimal conditions. After that, after a certain period of time (100-500 h), it will be necessary to carry out the procedure for removing coke deposits from the surface of the catalyst by treating it with regenerating gas (O ₂ + N ₂ ) at a temperature of 340-420 ° C under circulating conditions. In pilot tests of a universal BFK under conditions of increased hydrogen content in the initial synthesis gas (functional f> 2.5), the period of its continuous active operation was about 1000 hours.

The number of oxidative regenerations of a single acid component of universal BFK (high-siliceous zeolite in the H-form of the HZSM-5 type) exceeds 35. In this case, the removal of coke deposits from the surface of the high-silica zeolite in the H-form of the HZSM-5 type is carried out by a regenerating gas (O ₂ + N ₂ ) at temperatures up to 520 ° C in circulating conditions, which is unacceptable for the regeneration of universal BFK.

According to data from scientific and technical sources [31, 32], the metal oxide component of universal BFK (reduced form SMS-4) during oxidative treatment does not change its catalytic properties and its service life in methanol synthesis is up to 3 years or more. The main factors that reduce the period of its active operation to 0.5-1.0 years are the high concentration of sulfur compounds in the synthesis gas (> 20 mg / m ³ ) and the accumulation of finely divided iron on the surface of the catalyst. With modern methods of purification of gases from sulfur compounds and protection of heat exchange equipment from carbonyl corrosion, these factors affecting the catalyst are practically absent.

The most typical mixed catalyst preparation procedure is described in the method for converting synthesis gas to aromatic hydrocarbons in the prototype [7] and is described in detail in Example 1 (an improved method for increasing the selectivity of aromatic hydrocarbon production).

Example 1 (from the prototype). Separate grinding of metal oxide (ZnO-Cr ₂ O ₃ -Al ₂ O ₃ ) and zeolite (HZSM-5) components to a particle size of <0.1 mm (in the prototype their size is 200 mesh) with their further mixing. After this, granulation of the resulting mixture is carried out with the formation of catalyst granules with a size of 0.5-2.0 mm The finished catalyst composition has a composition (% wt): 16% ZnO, 44% Cr ₂ O ₃ , 30% Al ₂ O ₃ and 10% ZSM-5. The experiments are carried out in a reactor with a fixed catalyst bed.

The synthesis gas having a molar ratio of H ₂ / CO = 1 is passed through the reactor with a space velocity of 1780 h ⁻¹ at a pressure of 8.4 MPa and a temperature of 427 ° C. After 19 hours of run, the conversion of CO + H ₂ is 37.7 mol%, and the content of aromatic hydrocarbons in the reaction products reaches 70.1% wt. of the amount of hydrocarbons obtained (97% by weight, calculated on the C ₅₊ hydrocarbon fraction), which is the best result of an improved method for the conversion of synthesis gas to aromatic hydrocarbons in comparison with the methods known at that time.

Based on the results of the experiment, the preparation of the mixed catalyst described in example 1 is not suitable for the preparation of BFK designed to convert synthesis gas to gasoline fractions with a moderate content of aromatic hydrocarbons (20-35% wt.), Not exceeding the permissible values in gasolines ecological classes Euro-4, Euro-5 and Euro-6.

In the prototype shown as examples (see. Room runs 316A, 300A and 299A) providing a C ₅₊ hydrocarbons (gasoline) with low content of aromatic hydrocarbons (17.2, 18.9 and 19.7 wt.%), But this there was a high side formation of C ₁ -C ₄ hydrocarbons (58.7, 66.6 and 57.8% wt., respectively) and a low content of C ₅₊ hydrocarbons in the total amount of hydrocarbons (41.3, 33.4 and 42.2 respectively % wt.).

Examples 2-7, 9, 11-17 are given below to illustrate the proposed method of preparing a universal BFK that meets the requirements of the task.

Examples 8, 10 and 18 are given below for comparison with the proposed method of preparation and use of universal BFK.

Example 2. Take 3 kg of TXA, dilute HOB and mix thoroughly. To the thus obtained colloidal solution (pH = 5), 285 ml of a 25% solution of NH ₃ are added, increasing the pH to 7.0-7.5. The resulting suspension of aluminum hydroxide is filtered through a vacuum filter and the residual mass is poured with HOV (1:10), left for 12 h to proceed with the deposition of amorphous aluminum hydroxide, then the precipitate is decanted and again filled with HOV. After the next decantation, the resulting mass of PHA contains 16.7% wt. Al (OH) ₃ and 83.3% wt. H ₂ O. The precipitate PHA (pH = 7) is dried in air to a residual moisture content of 30% wt. for use as a binder component of a bifunctional catalyst.

Tablets of a reduced methanol synthesis catalyst with sodium oxide content <0.03% wt. and iron oxide <0.04% wt. crushed in a ball mill to a particle size <0.3 mm The obtained powder (having a pH of an aqueous extract of ~ 7) is mixed in a weight ratio of 70/30 with a high silica zeolite powder in the H-form of the HZSM-5 type (molar ratio SiO ₂ / Al ₂ O ₃ = 92, sodium oxide content <0.04% wt., pH aqueous extract ~ 7). The acid component HZSM-5 with increased stability used in examples 2-11 was obtained in accordance with [33]. A mixture of active components, a reduced catalyst for the synthesis of methanol and zeolite in the H-form of the type HZSM-5, is thoroughly mixed.

The dry mixture obtained in an amount of 170 g is placed in a 0.5 L paddle mixer. The binder component of PHA 30% humidity with the content of sodium, potassium and calcium oxides <0.03% wt. each calculated on the dry weight of the binder component is added to the mixer in an amount of 30 g (in terms of Al ₂ O ₃ ) and mixed again for 30 minutes. Then, in a three-component mixture, 70 ml of distilled water (pH = 6.6) are added in small portions with continuous stirring over 1 hour to obtain a homogeneous pasty mass at a temperature of 20 ° C with a mass ratio of components: 59.5% metal oxide catalyst / 25.5 % HZSM-5/15% binder in terms of Al ₂ O ₃ .

The resulting paste is passed at least 2 times through a device for grinding materials, in which the cutting unit consists of a rotating figured knife interacting with a fixed grill with through channels. Extrudates are formed using a syringe on a die with a hole diameter of 3 mm using a plastic mass (pH of an aqueous extract ~ 7) at a temperature of 20 ° C. The extrudates are dried in air for 48 hours, and then dried in an oven at a temperature of 120 ° C for 4 hours.

The prepared extrudates of universal BFK are examined for catalytic activity in the conversion of synthesis gas in a flow-type laboratory apparatus with circulation of a gas stream after condensation of liquid products. For research, a catalyst fraction of 0.25-0.5 mm is prepared and loaded into a laboratory reactor in an amount of 33 cm ³ .

The universal BFK calcination procedure is performed after loading a catalyst fraction of 0.25-0.5 mm into a fixed-bed synthesis gas conversion reactor, initially in a stream of nitrogen at a temperature of 200-320 ° C, then in a stream of synthesis gas at a temperature of 320-400 ° C in circulating conditions with a multiplicity of circulation of about 25.

The experiments are carried out at a pressure of 8 MPa and an average temperature in the catalyst layer of 400 ° C while passing synthesis gas mixed with circulating gas through a BFK layer.

A synthesis gas containing (in% vol.): 63.7% H ₂ , 33.7% CO, 0.1% CO ₂ , 1.5% N ₂ and 1.0% CH ₄ , is fed to the plant with a space velocity of 840 h ⁻¹ , where it is mixed with the circulation gas before entering the reactor with a circulation ratio of 25.

The vapor-gas stream, after contacting with a universal BFK, is cooled and liquid products are separated in the separator from the gas phase. Liquid products are separated into a gasoline fraction and methanol water, partially separating CO ₂ and C ₃ -C ₄ hydrocarbons dissolved in them. To prevent the accumulation of methane and light hydrocarbons, part of the gas stream after the separator is constantly removed from the circulation circuit in the form of purge gas, and the main gas stream is mixed with the original synthesis gas and fed to the hydrocarbon synthesis reactor.

As a result of the synthesis gas conversion, a CO conversion of about 91% was achieved; the selectivity for the formation of C ₅₊ hydrocarbons was 82% by weight. the amount of hydrocarbons formed when the content of aromatic hydrocarbons 34% wt. in the C ₅₊ hydrocarbon fraction. The benzene content in liquid hydrocarbons was <0.1% wt. The concentration of methanol in the aqueous fraction of liquid products was equal to 6.3% wt.

Example 3. In a porcelain mortar mixed 24 g of powder of high silica zeolite in the H-form of the type HZSM-5 (molar ratio SiO ₂ / Al ₂ O ₃ = 72, the content of sodium oxide <0.04% wt., PH of the aqueous extract ~ 7) and 56 g of crushed pre-reduced catalyst for the synthesis of methanol CMC-4 (sodium oxide content <0.03% wt. and iron oxide <0.04% wt.). Solid mortar of zeolite in the resulting mixture with SMS-4 is thoroughly ground in a mortar for no more than 30 minutes. The obtained homogeneous dry mixture of active components is transferred to a 250 ml paddle mixer and stirring is continued for ~ 20 min. PHA taken from an industrial batch is added to the mixer (humidity 53.7%, pH = 7, the content of sodium, potassium and calcium oxides <0.03% wt. Each calculated on the dry weight of the binder component). The resulting mass of bifunctional catalyst, containing in mass percent (on a “dry” basis): 56.8% of the metal oxide catalyst SMS-4, 24.4% HZSM-5 and 18.8% of the binder component in terms of Al ₂ O ₃ are mixed in the mixer for 35 minutes Then add 13 ml of distilled water (pH = 6.6) and mix for another 25 min at a temperature of 30 ° C.

After performing the above operations, the catalytic mass becomes sufficiently ductile for extrusion. From the obtained plastic mass at room temperature (at least 20 ° C) the extrudates of the bifunctional catalyst are formed using a syringe on a die with an opening diameter of 3 mm. The wet extrudates are dried in air for 24 hours and dried in an oven at a temperature of 120 ° C for 6 hours.

The prepared extrudates of universal BFK are examined for catalytic activity in the conversion of synthesis gas in a flow-type laboratory apparatus with circulation of a gas stream after condensation of liquid products. For research, prepare a catalyst fraction of 0.25-0.5 mm and load it into a laboratory reactor in an amount of 10 cm ³ .

The universal BFK calcination procedure is performed after loading a catalyst fraction of 0.25-0.5 mm into a fixed-bed synthesis gas conversion reactor, initially in a stream of nitrogen at a temperature of 200-320 ° C, then in a stream of synthesis gas at a temperature of 320-400 ° C in circulating conditions with a circulation ratio of about 10.

The experiments are carried out at a pressure of 8 MPa and an average temperature in the catalyst layer of 400 ° C while passing synthesis gas mixed with circulating gas through a BFK layer.

Synthesis gas containing (in% vol.): 66.4% H ₂ , 33.2% CO, 0.3% CO ₂ , 0.1% N ₂ and <0.1% CH ₄ , is fed to the installation with a space velocity of 730 h ^-1 , where it is mixed with the circulation gas before entering the reactor with a circulation ratio of about 9.

The vapor-gas stream, after contacting with a universal BFK, is cooled and liquid products are separated in the separator from the gas phase. Liquid products are separated into a gasoline fraction and methanol water, partially separating CO ₂ and C ₃ -C ₄ hydrocarbons dissolved in them. To prevent the accumulation of methane and light hydrocarbons, part of the gas stream after the separator is constantly removed from the circulation circuit in the form of purge gas, and the main gas stream is mixed with the original synthesis gas and fed to the hydrocarbon synthesis reactor.

After 86 hours of universal BFK run, the conversion of carbon monoxide was about 82%, the selectivity for the formation of C ₅₊ hydrocarbons was 78% wt. the amount of hydrocarbons formed with an aromatic hydrocarbon content of 28% wt. in the C ₅₊ hydrocarbon fraction. The content of benzene in liquid hydrocarbons was <0.4% wt. The concentration of methanol in the aqueous fraction of liquid products was equal to 2.5% wt.

After reducing the pressure in the installation to 2 MPa and lowering the temperature in the reactor to 340 ° C, hexene-1 is fed into the catalytic reactor together with the initial synthesis gas at a weight rate of 0.7 h ^-1 . During the supply of hexene-1 to the reactor at a pressure of 2 MPa, a temperature of 340 ° C and a space velocity of the initial synthesis gas of 800 h ^-1 , the CO conversion was 50%, and the degree of conversion of hexene-1 was about 100%. The selectivity of the formation of C ₅₊ hydrocarbons in the amount of hydrocarbons formed increased to 93% wt. The content of aromatic hydrocarbons in the fraction of hydrocarbons With ₅₊ decreased to 20% wt. The benzene content in liquid hydrocarbons decreased to 0.1% wt., And the concentration of methanol in the aqueous fraction of liquid products decreased to a level of <0.1% wt. The amount of C ₅₊ hydrocarbons in liquid products increased 7.7 times due to the additional formation of C ₇₊ iso-olefins, the liquid products of hexene-1 conversion resulting from methylation reactions of hexene-1 with methanol and dimethyl ether. C ₄ -C ₁₀₊ iso-olefins are obtained as a result of the oligomerization of hexene-1 and gaseous olefins, intermediate products of methanol conversion on the zeolite component of universal BFK.

Example 4. Take a powder of high silica zeolite in the H-form of the type HZSM-5 (molar ratio SiO ₂ / Al ₂ O ₃ = 72, the content of sodium oxide <0.04 wt.%, PH of the aqueous extract ~ 7) and tablets of the restored synthesis catalyst methanol SMS-4 (content of sodium oxide <0.03% wt. and iron oxide <0.04% wt., pH of the aqueous extract ~ 7). They are loaded into a ball mill in a mass ratio of 30/70, after which the components are mixed with grinding tablets SMS-4 to a particle size <0.3 mm. Based on the capacity of the ball mill, about 600 g of a homogeneous dry mixture of active components are made. A portion of 200 g is taken from the resulting mixture, placed in a 500 ml paddle mixer. With stirring, add in small portions of PHA taken from an industrial batch (humidity 53.7%, pH = 7, the content of sodium, potassium and calcium oxides <0.03% wt. Each, calculated on the dry weight of the binder component) in an amount of 40 g in terms of Al ₂ O ₃ .

The obtained catalytic mass of BFK, containing in mass percent (on "dry" weight): 58.3% metal oxide catalyst, 25% HZSM-5 and 16.7% of the binder component in terms of Al ₂ O ₃ , stirred for 40 minutes, and then in the process of dosed addition to it of 26 ml of distilled water (pH = 6.6) is stirred for another 1 hour

The wet mass (pH ~ 7) is heated in a paddle mixer to a temperature of 40 ° C and in the process of hot mixing at a temperature of 40 ° C after 20-30 minutes a homogeneous mixture with sufficient ductility for piston extrusion is obtained. Extrudates are formed from the obtained plastic mass with a temperature of 30-40 ° C using a heated syringe on a die with a hole diameter of 3 mm. Wet extrudates are dried in air for 50 hours, then broken to a minimum length of 4-5 mm, grinded from the ends and dried in an oven at a temperature of 120 ° C for 4 hours.

The universal BFK granules prepared in this way are examined for catalytic activity in the process of converting synthesis gas in a flow-type laboratory apparatus with circulation of a gas stream after condensation of liquid products. For research, the obtained smooth (without defects) granules 3 × 4-5 mm in size are loaded into a 220 cm ³ laboratory reactor.

The universal BFK calcination procedure is carried out after loading synthesis gas with a fixed catalyst bed into the conversion reactor, initially in a stream of nitrogen at a temperature of 200-320 ° C, then in a stream of synthesis gas at a temperature of 320-400 ° C in circulation conditions with a circulation ratio of about 20 .

The experiments are carried out at a pressure of 8 MPa and an average temperature in the catalyst layer of 400 ° C while passing synthesis gas mixed with circulating gas through a BFK layer.

Synthesis gas containing (in% vol.): 65.3% H ₂ , 31.6% CO, 3.0% CO ₂ , 0.1% N ₂ and <0.1% CH ₄ , is fed to the installation with a space velocity of 650 h ^-1 where it is mixed with the circulating gas before entering the reactor with a circulation ratio of about 20. The vapor-gas stream after contacting with a universal BFK is cooled and liquid products are separated in the separator from the gas phase. Liquid products are separated into a gasoline fraction and methanol water, partially separating CO ₂ and C ₃ -C ₄ hydrocarbons dissolved in them. To prevent the accumulation of methane and light hydrocarbons, part of the gas stream after the separator is constantly removed from the circulation circuit in the form of purge gas, and the main gas stream is mixed with the original synthesis gas and fed to the hydrocarbon synthesis reactor.

After 470 hours of universal BFK run, the conversion of carbon monoxide was about 86%, the selectivity for the formation of C ₅₊ hydrocarbons was 76% wt. the amount of hydrocarbons formed with an aromatic hydrocarbon content of 30% wt. in the C ₅₊ hydrocarbon fraction. The content of benzene in liquid hydrocarbons was <0.4% wt. The concentration of methanol in the aqueous fraction of liquid products was equal to 6.5% wt.

After 474 hours of universal BFK run, toluene is fed to the catalytic reactor together with the initial synthesis gas at a weight rate of about 0.04 h ^-1 without changing the pressure and temperature in the reactor. The supply of toluene to the reactor is carried out in a weight ratio of toluene / synthesis gas equal to 1/10.

8 hours after the toluene feed, the carbon monoxide conversion exceeded 89%. The toluene conversion was about 95%. The selectivity of the formation of C ₅₊ hydrocarbons was 84% wt. the amount of hydrocarbons formed. The aromatic hydrocarbon content in the C ₅₊ hydrocarbon fraction increased to 55% by weight. due to alkylation products of toluene with synthesis gas - xylenes and pseudocumene. The benzene content in liquid hydrocarbons decreased to 0.1% wt, and the methanol concentration in the aqueous fraction of liquid products decreased to a level of <0.5% wt.

The obtained high-octane gasoline with a high content of aromatic hydrocarbons can be used to compound gasoline fractions with a low content of aromatic hydrocarbons, for example, gasoline fractions obtained on a universal BFK from synthesis gas with a high hydrogen content, where the functional f = (Н ₂ -CO ₂ ) / (CO + CO ₂ )> 2.

Example 5. Tablets of a reduced catalyst for the synthesis of methanol SMS-4 with a sodium oxide content of <0.03% wt. and iron oxide <0.04% wt. crushed in a ball mill to a particle size <0.3 mm A portion of the obtained CMC-4 powder in an amount of 657 g is mixed with a high silica zeolite powder in the H-form of the HZSM-5 type (molar ratio SiO ₂ / Al ₂ O ₃ = 45, pH of the aqueous extract ~ 7) in a ratio of 65/35. The mixture of active components is transferred to a 5 L mixer, added in small portions of PHA taken from an industrial batch (humidity 60%, pH = 7, the content of sodium, potassium and calcium oxides <0.03% by weight of each calculated on the dry weight of the binder component) in an amount of 248 g in terms of Al ₂ O ₃ and stirred for 30 minutes The ratio of components in the final mixture (% wt.): 52.2% metal oxide catalyst, 28.1% HZSM-5 and 19.7% binder in terms of Al ₂ O ₃ .

With stirring, distilled water (pH = 6.6) is added portionwise to the mixture in such an amount that a mass is obtained that is close to plastic in properties, but with a small (within 2%) lack of moisture. The resulting mass is passed several times through a device for grinding materials, equipped with a rotating figured knife in contact with the fixed grid with through channels of round shape with a diameter of 10 mm After each passing of the wet mixture through the chopper, the plasticity of the mass increases without adding water or a binder. Three times the wet mass was machined with a grinder to achieve its required homogeneity and ductility. After this, it is necessary, if possible without delay in time, to use the finished plastic mass at a temperature of ≥20 ° C for the BFK molding procedure.

For the formation of BFK use a special extruder equipped with a screw with a constant pitch and an increased depth of the furrows. For him, special dies were made with holes with a diameter of 4 mm, which are located closer to the center to prevent the formation of plugs.

The resulting extrudates, having a diameter of about 4 mm, are dried for 48-72 hours in air, then broken to a minimum length of 5-10 mm and dried in an oven at a temperature of 120 ° C for 6 hours.

The universal BFK granules prepared in this way are examined for catalytic activity in the process of converting synthesis gas in a flow-type experimental setup with gas flow circulation after condensation of liquid products.

To carry out pilot studies, granules of universal BFK with a diameter of 4 mm and a length of up to 10 mm are loaded into one of the four experimental reactors in an amount of 0.004 m ³ .

The universal BFK calcination procedure is performed after loading synthesis gas with a fixed catalyst bed into the conversion reactor, initially in a stream of nitrogen at a temperature of 200-320 ° C, then in a stream of synthesis gas at a temperature of 320-400 ° C under circulating conditions with a circulation ratio of about 24 .

The experiment is carried out at a pressure of 4 MPa and a maximum temperature at the outlet of the reactor of 425 ° C while passing synthesis gas mixed with circulating gas through a BFK layer under adiabatic conditions.

A synthesis gas having a ratio of components: (H ₂ —CO ₂ ) / (CO + CO ₂ ) = 2.58 and CO / CO ₂ = 18.05 is fed to the experimental setup at a space velocity of 625 h ⁻¹ , where it is mixed with the circulation gas before entering the reactor with a circulation ratio of about 24. After contact with the universal BFK, the gas-vapor stream is cooled in air and then in water coolers. The cooled gas-liquid mixture is sent to a high-pressure separator, where liquid products are separated from the gas stream. Liquid products are separated into a gasoline fraction and methanol water, partially separating CO ₂ and C ₃ -C ₄ hydrocarbons dissolved in them. To prevent the accumulation of methane and light hydrocarbons, part of the gas stream after the separator is constantly removed from the circulation circuit in the form of purge gas, and the main gas stream is mixed with the original synthesis gas and fed to the hydrocarbon synthesis reactor.

In the experiment, the conversion of carbon monoxide was about 90%, and the conversion of H ₂ <80%, which affected the accumulation of hydrogen in the circulating gas. The obtained gasoline fraction of hydrocarbons before stabilization contained 88.5% wt. hydrocarbons With ₅₊ and 11.5% wt. hydrocarbons C ₃ -C ₄ . After stabilization of gasoline, aromatic hydrocarbons amounted to 10% wt. calculated on the liquid fraction of C ₅₊ hydrocarbons. The benzene content in liquid hydrocarbons did not exceed 0.3% wt., And the concentration of methanol in the aqueous phase of the liquid products was <0.1% wt. The performance of the universal BFK was 90 g of gasoline / l of catalyst / h. After stabilization of the product, the octane number of gasoline did not exceed 90 IM (units according to the research method).

In the synthesis gas conversion process, toluene is fed into an adiabatic reactor for conversion at a weight rate of 0.02 h ^-1 without changing the pressure and temperature in the reactor. The volumetric rate of the initial synthesis gas and the multiplicity of the circulation of the gas stream remain at the same level, respectively, 625 h ^-1 and 24.

During the supply of toluene to the reactor together with the initial synthesis gas, the CO conversion increased to 92%. The toluene conversion was 95%. In the obtained unstable gasoline fraction of hydrocarbons, the content of C ₅₊ hydrocarbons increased to 91% wt. and reduced the amount of dissolved hydrocarbons With ₃ -C ₄ up to 9% wt. After stabilization of gasoline, aromatic hydrocarbons amounted to 25% wt. calculated on the liquid fraction of C ₅₊ hydrocarbons. The benzene content in liquid hydrocarbons did not exceed 0.1% wt., And the concentration of methanol in the aqueous phase of the liquid products was <0.1% wt. The performance of the universal BFK reached 110 g of gasoline / l of catalyst / h. After stabilization of the product, the octane number of gasoline obtained by adding toluene to the synthesis gas increased to 92 IM. The content of aromatic hydrocarbons in the liquid fraction of C ₅₊ hydrocarbons increased from 10% to 25% by weight, mainly due to the products of toluene alkylation with synthesis gas - xylenes and pseudocumene.

Thus, due to the process of toluene alkylation in the synthesis gas conversion reactor at the same universal BFK, it is possible to significantly increase the content of aromatic hydrocarbons in the liquid C ₅₊ hydrocarbon fraction, increase the performance of universal BFK in gasoline, and also increase the octane number of gasoline to ≥ 92 IM without increasing pressure, process temperature and volumetric feed rate of the feed synthesis gas.

The addition of toluene to the synthesis gas at the inlet to the reactor (examples 4 and 5) allows, at minimal cost, without stopping the process and replacing BFK with the same process parameters, to obtain a better product with increased selectivity and productivity.

Example 6. Tablets of a reduced methanol synthesis catalyst with sodium oxide content <0.03% wt. and iron oxide <0.04% wt. crushed in a ball mill to a particle size <0.3 mm and the resulting powder is mixed in a ratio of 70/30 with a powder of high silica zeolite in the H-form of the type HZSM-5 (molar ratio SiO ₂ / Al ₂ O ₃ = 65, pH of the aqueous extract ~ 7) with a content of sodium oxide of 0.01% wt. The resulting dry mixture (bifunctional mixture) in an amount of 16 kg is thoroughly mixed in a paddle mixer with a working volume of 25 l for 1 hour. Then, a binder component of 70% moisture TCA with a content of sodium oxide of 0.02% by weight is added to the mixer. and pH ~ 7 in the amount of 3.4 kg in terms of Al ₂ O ₃ . The BFK components are again mixed for 1 h at a temperature of 20 ° C.

The finished mass of the composition in% wt. (on a “dry” basis): 57.8% metal oxide catalyst, 24.7% HZSM-5 and 17.5% binder in terms of Al ₂ O ₃ , are molded at a temperature of ≥ 20 ° C on a plunger press with a loading volume of 5 l under pressure from 4 to 10 MPa. The molding pressure is increased as the moisture content of the mass decreases.

The obtained extrudates of a universal BFK with a diameter of 4 mm are dried in air for at least 24 hours, then they are broken to a minimum length of 5-10 mm and dried in an oven at a temperature of 120 ° C for 6 hours. The maximum mechanical strength of the granules for crushing along the generatrix was 6 , 0 MPa, the minimum strength is not less than 3.0 MPa.

Example 7. Based on the achieved high indicators of the mechanical strength of the granules for crushing, obtained by the piston (plunger) extrusion method, the present invention proposes a method developed by the authors for the production of universal fine-spherical BFC.

The procedure for preparing the mass for molding is similar to the procedure described in example 6.

The finished mass of the composition in% wt. (on a “dry” basis): 57.8% metal oxide catalyst, 24.7% HZSM-5 and 17.5% binder in terms of Al ₂ O ₃ , are molded at a temperature of ≥ 20 ° C on a plunger press with a loading volume of 5 l under pressure from 4 to 10 MPa. The molding pressure is increased as the moisture content of the mass decreases.

The obtained extrudates of a universal BFK with a diameter of 4 mm are dried in air for ≥ 24 hours and dried in an oven at a temperature of 120 ° C for 4 hours. The maximum mechanical strength of the granules for crushing along the generatrix was 6.0 MPa, the minimum strength was not less than 3.0 MPa

The extrudates dried in an oven are broken in a special drum device with partitions to obtain BFK granules up to 20 mm long. The granules are calcined in an oven while slowly raising the temperature from room temperature (~ 20 ° C) to a temperature of 400 ° C.

BFK granules calcined at a temperature of 400 ° C for 4 hours are crushed to obtain fractions of various grain sizes of irregular shape: 0.05-0.25 mm, 0.25-0.5 mm, 0.5-1.0 mm and 1 , 0-2.0 mm.

The obtained fractions of 0.5-1.0 mm and 1.0-2.0 mm of irregularly shaped BFK grains are run in a drum device until spherical grains are formed. During the run-in from the grains of these fractions, when they are split, finer-grained fractions are obtained, which are also run in the drum. As a result, after a run-in in a drum device, a wide fraction of spherical-shaped grains from 0.1 to 2.0 mm is obtained. After the fractionation procedure, a working narrow fraction of universal fine-spherical BFK grains is selected for loading into the reactors.

To determine the average attrition rate of the obtained universal small-spherical BFK, a fraction of irregular-shaped grains of 0.4-1.0 mm was selected. The run-in procedure was performed and a wide fraction of spherical-shaped grains from 0.1 to 0.8 mm was obtained. The obtained fraction was loaded into the MP-8I device, which serves to determine the abrasion of micro- and small-spherical catalysts and sorbents. The maximum speed of the inner drum in the device is 5600 rpm. For the first 12.5 minutes of testing in the MP-8I device, the small-spherical BFK in the most severe conditions lost 5% wt. from the loaded amount, i.e. the attrition rate was 0.4% w / min. Further, the attrition rate decreased to 0.35% wt./min and stabilized at this level. As a comparison, the best abrasion catalyst is γ-Al ₂ O ₃ , individual samples of which showed a maximum attrition rate of 0.37% wt./min with a working norm for γ-Al ₂ O ₃ not more than 0.30% wt. / min

Thus, the prepared universal small-spherical BFK in terms of abrasion is quite suitable for use in the process of producing high-octane gasoline from synthesis gas or other combined processes for the synthesis gas synthesis in reactors with a fluidized (“boiling”) catalyst bed.

Example 8 (for comparison). Fine-spherical BFC for the conversion of synthesis gas to hydrocarbons is obtained from the pseudo-sol of aluminum hydroxide by peptization of the wet mass of aluminum hydroxide with acid, introducing into the pseudo-sol of the dry bifunctional mixture from Example 6 (reduced methanol synthesis catalyst / HZSM-5 = 70/30), homogenization of a metal oxide zeolite-containing pseudo-sol, hydrocarbon-ammonia molding to obtain granules with a size of 0.25-0.4 mm All operations for the preparation of a small-spherical BFK by the method of liquid molding were performed at the Leyna enterprise (GDR) in 1986.

A freshly prepared sample of fine-spherical BFC with a granule size of 0.25-0.4 mm in an amount of 150 cm ^{3 is} examined for catalytic activity in the conversion of synthesis gas in a flow-type laboratory apparatus with gas flow circulation after condensation of liquid products.

The procedure for calcining the fine-spherical BFK is carried out after loading synthesis syngas with a fluidized (“boiling”) catalyst bed initially in a stream of nitrogen at a temperature of 200-320 ° C, then in a stream of synthesis gas at a temperature of 320-400 ° C under circulating conditions with a multiplicity of circulation of about 20.

After the end of the calcination procedure, the temperature in the reactor was reduced to 100 ° C and the drain was separated from the separator. About 30 ml of a dark green liquid (pH = 12) with a strong smell of ammonia merged. A large amount of ammonia was found in the circulating gas. The aqueous extract from the prepared small-spherical BFC of yellow-green color had a strongly alkaline reaction and a strong smell of ammonia.

The fine-spherical BFK was discharged from the reactor, the calcination of the catalyst was continued in an oven in air with a slow rise in temperature to 380 ° C. After the calcination procedure, the dark green color of the fine-spherical BFK changed and turned gray in the initial dry bifunctional mixture from Example 6.

An oven-baked sample of fine-spherical BFK with a granule size of 0.25-0.4 mm in an amount of 100 cm ^{3 was} examined for catalytic activity in the conversion of synthesis gas in a flow-type laboratory apparatus with gas flow circulation after condensation of liquid products.

The experiments were carried out at a pressure of 5 MPa and an average temperature in the catalyst bed of 380 ° C while passing synthesis gas (H ₂ / CO = 2) in a mixture with circulating gas through a fluidized bed of fine-spherical BFC.

The synthesis gas is fed to the installation with a space velocity of 500 h ^-1 , where it is mixed with the circulating gas before entering the reactor. The vapor-gas stream, after contacting with the fine-spherical BFK, is cooled and liquid products are separated in the separator from the gas phase. Liquid products are separated into a gasoline fraction and methanol water, partially separating CO ₂ and C ₃ -C ₄ hydrocarbons dissolved in them. To prevent the accumulation of methane and light hydrocarbons, part of the gas stream after the separator is constantly removed from the circulation circuit in the form of purge gas, and the main gas stream is mixed with the original synthesis gas and fed to the hydrocarbon synthesis reactor.

Tests of the small-spherical BFK prepared by liquid molding and calcined in an oven in air at a temperature of 380 ° C showed the absence of liquid hydrocarbons during the conversion of CO and H ₂ . As a result of the synthesis gas conversion, an aqueous fraction and non-condensing gaseous hydrocarbons were obtained, which amounted to (wt%): 17.1% CH ₄ , ~ 0.8% C ₂ H ₆ , 22.3% C ₃ H ₈ , 31 4% ΣC ₄ , 20.2% iso-C ₅ , 8.2% iso-C ₆ . The concentration of methanol in the aqueous fraction was equal to 0.3% wt.

Example 9. Tests in a laboratory catalytic installation of fine-spherical BFC prepared in example 7 according to the method developed by the authors of the present invention.

A freshly prepared sample of small-spherical BFC with a granule size of 0.2-0.3 mm in an amount of 100 cm ^{3 is} examined for catalytic activity in the conversion of synthesis gas in a flow-type laboratory apparatus with gas flow circulation after condensation of liquid products.

The procedure for calcining the fine-spherical BFK is carried out after loading synthesis syngas with a fluidized (“boiling”) catalyst bed initially in a stream of nitrogen at a temperature of 200-320 ° C, then in a stream of synthesis gas at a temperature of 320-400 ° C under circulating conditions with a multiplicity of circulation of about 20.

The experiments were carried out at a pressure of 5 MPa and an average temperature in the catalyst bed of 380 ° C while passing synthesis gas (H ₂ / CO = 2) in a mixture with circulating gas through a fluidized bed of fine-spherical BFC.

The synthesis gas is fed to the installation with a space velocity of 500 h ^-1 where it is mixed with the circulation gas before entering the reactor. The vapor-gas stream, after contacting with the fine-spherical BFK, is cooled and liquid products are separated in the separator from the gas phase. Liquid products are separated into a gasoline fraction and methanol water, partially separating CO ₂ and C ₃ -C ₄ hydrocarbons dissolved in them. To prevent the accumulation of methane and light hydrocarbons, part of the gas stream after the separator is constantly removed from the circulation circuit in the form of purge gas, and the main gas stream is mixed with the original synthesis gas and fed to the hydrocarbon synthesis reactor.

In the experiments, the conversion of carbon monoxide was about 88%. As a result of the synthesis gas conversion, an aqueous fraction, a gasoline fraction (liquid hydrocarbons), and non-condensable gaseous hydrocarbons were obtained, which amounted to (% wt.): 14.6% CH ₄ , ~ 2.9% C ₂ H ₆ , 19.3 % C ₃ H ₈ , 37.2% iso-C ₄ , 20.9% iso-C ₅ , 5.1% iso-C ₆ . The obtained gasoline fraction of hydrocarbons before stabilization contained about 89% wt. hydrocarbons With ₅₊ and about 11% wt. hydrocarbons C ₃ -C ₄ . Aromatic hydrocarbons accounted for 32% wt. calculated on the liquid fraction of C ₅₊ hydrocarbons. The benzene content in liquid hydrocarbons did not exceed 0.3% wt., And the concentration of methanol in the aqueous phase of liquid products was <2% wt. The maximum performance of fine-spherical BFC at a pressure of 5 MPa, a temperature of 380 ° C and a volumetric feed rate of the feed synthesis gas of 500 h ^-1 was 70-75 g of gasoline / l of catalyst / h.

Example 10 (for comparison). The formation of a universal BFK with a binder content is lower than in the proposed method.

The procedure for preparing the mass for molding is similar to the procedure described in example 6. The resulting wet mixture of the three components of the composition in% wt. (on a “dry” basis): 64.7% metal oxide catalyst, 27.7% HZSM-5 and 7.6% binder in terms of Al ₂ O ₃ , with a temperature of 60 ° С, are formed on a ПШ-50 screw extruder through a die with a hole diameter of 5 mm. With decreasing temperature, the plasticity of the mixture deteriorated and a “dry” plug formed in front of the die. After replacing a die with a hole diameter of 5 mm with a die with a hole diameter of 8 mm, while maintaining the temperature of the mixture at 60 ° C, the molding process was carried out without interruption.

The obtained extrudates of universal BFK with a diameter of 8 mm are dried in air for 48-72 hours and dried in an oven at a temperature of 120 ° C for 4 hours.

The maximum mechanical strength of the prepared BFK granules for crushing along the generatrix was 2.0 MPa, the minimum strength was not less than 0.7 MPa.

Thus, the results obtained in example 10 show that with a low binder content (below 10% in terms of Al ₂ O ₃ ) and certain process conditions are observed (mixture temperature at 60 ° C, the diameter of the holes of the die is not less than 8 mm ) it is possible to carry out the formation of BFK on a screw extruder. However, in this case, the BFK granules are not sufficiently strong when crushed along the generatrix after drying for 4 hours at a temperature of 120 ° C.

Example 11. Take 36.3 kg of wet mass of the component composition (on a “dry” mass) as in example 9 (64.7% metal oxide catalyst, 27.7% HZSM-5 and 7.6% binder in terms of Al ₂ O ₃ ), add a binder component of TCA 75% humidity with a content of sodium oxide of 0.02% wt. and pH = 7 in an amount of 9.0 kg. The mixture is stirred for 1 h in a paddle mixer with a displacement of 50 l at a temperature of 50 ° C. The resulting plastic mass containing in mass percent (on “dry” mass): 60.0% metal oxide catalyst, 25.8% HZSM-5 and 14.2% of the binder component in terms of Al ₂ O ₃ , with a temperature of 50 ° C (pH ~ 7) is formed on a screw extruder ПШ-50 through a die with a hole diameter of 5 mm.

The extrudates of universal BFK are dried in air for 48-72 hours and dried in an oven at a temperature of 120 ° C for 6 hours. The maximum mechanical strength of the prepared BFK granules for crushing along the generatrix was 3.8 MPa, the minimum strength was at least 2, 7 MPa.

Example 12. The procedure for preparing a three-component mixture is performed as in example 6, based on another composition of the BFC, containing in mass percent (on a “dry” basis): 63.0% metal oxide catalyst, 27.0% zeolite type HZSM-5 and 10, 0% binder component in terms of Al ₂ O ₃ .

To mix the BFK components, a 10-liter mixer is used, at a temperature of 20 ° C the mixture is passed at least 2 times through a material grinding device, in which the cutting unit consists of a rotating figured knife and a fixed lattice with through channels, and the resulting plastic mass (pH of an aqueous extract ~ 7) in the amount of 9 kg is formed at a temperature of a heated mass of 60 ° C using a screw extruder ПШ-45 through a die with holes with a diameter of 5 mm. At this extremely low concentration of the binder component in the mixture (10.0% binder in terms of Al ₂ O ₃ ), a decrease in the temperature of the mixture and loss of moisture leads to the formation of dry plugs and the molding process stops.

The obtained extrudates of universal BFK are dried in air for 48-72 hours and dried in an oven at a temperature of 120 ° C for 4 hours. The maximum mechanical strength of the prepared BFK granules for crushing along the generatrix was 3.5 MPa, the minimum strength was not less than 2 5 MPa.

Example 13. Tablets of a reduced catalyst for the synthesis of methanol SMS-4 with a sodium oxide content of <0.03% wt. and iron oxide <0.04% wt. crushed in a ball mill to a particle size <0.3 mm The powder SMS-4, obtained in an amount of 8.4 kg, is mixed with 3.6 kg of powder of high silica zeolite in the H-form of the type HZSM-5 (molar ratio SiO ₂ / Al ₂ O ₃ = 75, pH of the aqueous extract ~ 7) s the content of sodium oxide of 0.02% wt. 3.0 kg of pseudoboehmite powder of 30% humidity (pH of the aqueous extract ~ 7) containing oxides of alkaline and alkaline earth elements is added to the mixture: sodium - 0.019% wt., Potassium - 0.022% wt. and calcium - 0.024% wt.

After 15 minutes of “dry” stirring of the listed BFK components, 2 L of distilled water (pH = 6.6) are added gradually over 30 minutes with constant stirring. Further, 200 ml of distilled water is added to the resulting mass every 10 minutes, thus bringing the total amount of added water to 3 liters. Stirring the wet mass (pH ~ 7) is completed approximately 4 hours after adding the first portion of water. As a result, at a temperature of 20 ° C, after passing the wet mixture at least 2 times through the device for grinding materials, a plastic homogeneous mass with optimal humidity is obtained.

For the formation of BFK use a special extruder equipped with a screw with a constant pitch and an increased depth of the furrows. Dies were made for it with holes with a diameter of 5 mm, located closer to the center to prevent the formation of plugs.

The extrudates of a universal BFK obtained at a temperature of 20 ° C are dried in air for 48-72 hours and dried in an oven at a temperature of 120 ° C for 4 hours. The maximum mechanical strength of the BFK granules for crushing along the generatrix was 3.4 MPa, the minimum strength - not less than 2.5 MPa.

Example 14. Tablets of a reduced catalyst for the synthesis of methanol SMS-4 with a sodium oxide content of <0.03% wt. and iron oxide <0.04% wt. crushed to a particle size <0.3 mm SMSC-4 powder is mixed in a 70/30 mass ratio with HZSM-5 type high silica zeolite powder (molar ratio SiO ₂ / Al ₂ O ₃ = 27, aqueous extract pH ~ 7) with a content of sodium oxide of 0.02% wt.

After 15 minutes of “dry” mixing of the BFK components (HZSM-5 / CMC-4 = 30/70), the resulting mixture was tabletted using a mold and a manual laboratory press. The prepared tablets are ground and sieved through stainless steel sieves.

The obtained fraction of universal BFK with an irregular grain size of 0.25-0.5 mm was investigated for catalytic activity in the conversion of synthesis gas in a flow-type laboratory apparatus with gas flow circulation after condensation of liquid products.

The experiments were carried out at a pressure of 8 MPa and an average temperature in the catalyst bed of 380 ° C while passing synthesis gas mixed with circulating gas through a BFC layer loaded into the reactor in an amount of 27 cm ³ .

The synthesis gas containing (in% vol.): 66.5% H ₂ , 33.0% CO, 0.4% CO ₂ and 0.1% N ₂ , is fed to the installation with a space velocity of 1130 h ^-1 where it is mixed with the circulation gas before entering the reactor with a circulation ratio of 21. The vapor-gas stream after contacting with the BFK is cooled and the liquid products are separated in the separator from the gas phase. Liquid products are separated into a gasoline fraction and methanol water, partially separating CO ₂ and C ₃ -C ₄ hydrocarbons dissolved in them. To prevent the accumulation of methane and light hydrocarbons, part of the gas stream after the separator is constantly removed from the circulation circuit in the form of purge gas, and the main gas stream is mixed with the original synthesis gas and fed to the hydrocarbon synthesis reactor.

As a result of the conversion of synthesis gas after 54 hours of run of pelletized BFK, the CO conversion was 82%, the selectivity for the formation of C ₅₊ hydrocarbons was 73% wt. the amount of hydrocarbons formed with an aromatic hydrocarbon content of 29% wt. in the C ₅₊ hydrocarbon fraction. The benzene content in liquid hydrocarbons was 0.2% wt. The concentration of methanol in the aqueous fraction of liquid products was equal to 1.5% wt.

Example 15. The procedure for preparing the molding mass is similar to the procedure described in Example 3. Instead of a powder of high silica zeolite in the H-form of the HZSM-5 type, crystalline silicoaluminophosphate powder with the SAPO-5 structure is used. The last portion (in the example 3-13 ml) of distilled water (pH = 6.6) is added to the paddle mixer very slowly until sufficient plasticity of the mass is obtained for extrusion in a syringe. After that, distilled water is no longer added. The mass is mixed for another 15-20 minutes at a temperature of 20 ° C and a wet mixture is passed at least 2 times through a device for grinding materials.

From the obtained plastic mass of the composition,% wt. (on a “dry” basis): 52.8% SMS-4 metal oxide catalyst, 28.4% SAPO-5 and 18.8% binder component in terms of Al ₂ O ₃ , at a temperature of 20 ° С, BFK extrudates are formed using syringe on a die with a hole diameter of 3 mm. The extrudates are dried in air for 50 hours and dried in an oven at a temperature of 120 ° C for 4 hours. For studies, a 0.25-0.5 mm catalyst fraction is prepared and loaded into a laboratory reactor in an amount of 10 cm ³ .

The universal BFK calcination procedure is performed after loading a catalyst fraction of 0.25-0.5 mm into a fixed-bed synthesis gas conversion reactor, initially in a stream of nitrogen at a temperature of 200-320 ° C, then in a stream of synthesis gas at a temperature of 320-400 ° C in circulating conditions with a multiplicity of circulation of about 15.

The experiments are carried out under flowing conditions at a pressure of 8 MPa and an average temperature in the catalyst layer of 380 ° C while passing synthesis gas with a molar ratio of H ₂ / CO = 2 through a BFK layer with a space velocity of 5500 h ^-1 .

As a result of the conversion of synthesis gas, the selectivity for the formation of C ₅₊ hydrocarbons was 39% wt. the amount of formed hydrocarbons with an aromatic hydrocarbon content of 44% wt. in the hydrocarbon fraction C ₅₊ . In the resulting aromatic hydrocarbons, about 74% wt. constitute polymethylbenzenes C ₁₀₊ and 26% wt. - methyl and other alkyl benzenes C ₆ -C ₉ . The benzene content in liquid hydrocarbons was about 1.0% wt. The concentration of methanol in the aqueous fraction of liquid products was equal to 19.8% wt.

Example 16. The procedure for preparing the molding mass is similar to the procedure described in Example 3. A finely ground mixture of crystalline silicoaluminophosphate with the SAPO-5 structure and high silica HZSM-5 type zeolite, taken in a weight ratio of 3/1, is used as the acid component of BFK .

The last portion (in example 3, it was 13 ml) of distilled water (pH = 6.6) was added to the paddle mixer very slowly until sufficient mass plasticity was obtained for extrusion in the syringe. After that, distilled water is no longer added. The mass is mixed for another 15-20 minutes at a temperature of 20 ° C and a wet mixture is passed at least 2 times through a device for grinding materials.

From the obtained plastic mass of the composition,% wt. (on a “dry” basis): 49.4% SMS-4 metal oxide catalyst, 21.2% SAPO-5, 10.6% HZSM-5 and 18.8% binder in terms of Al ₂ O ₃ , at a temperature At 20 ° C, BFK extrudates are formed using a syringe on a die with a hole diameter of 3 mm. The extrudates are dried in air for 48 hours and dried in an oven at a temperature of 120 ° C for 4 hours. For studies, a catalyst fraction of 0.25-0.5 mm is prepared and loaded into a laboratory reactor in an amount of 10 cm ³ .

The universal BFK calcination procedure is performed after loading a catalyst fraction of 0.25-0.5 mm into a fixed-bed synthesis gas conversion reactor, initially in a stream of nitrogen at a temperature of 200-320 ° C, then in a stream of synthesis gas at a temperature of 320-400 ° C in circulating conditions with a multiplicity of circulation of about 15.

The experiments are carried out under flowing conditions at a pressure of 8 MPa and an average temperature in the catalyst bed of 380 ° C while passing synthesis gas with a molar ratio of H ₂ / CO = 2 through a BFK layer with a space velocity of 6200 h ^-1 .

As a result of the conversion of synthesis gas, the selectivity for the formation of C ₅₊ hydrocarbons was 51% wt. the amount of hydrocarbons formed with an aromatic hydrocarbon content of 33% wt. in the C ₅₊ hydrocarbon fraction. In the resulting aromatic hydrocarbons, about 80% wt. constitute polymethylbenzenes With ₁₀₊ and 20% wt. - methyl and other alkyl benzenes C ₆ -C ₉ . The benzene content in liquid hydrocarbons was <0.5% wt. The concentration of methanol in the aqueous fraction of liquid products was equal to 5.4% wt.

Example 17. Procedure for the mass preparation of molding procedure similar to that described in Example 3. Instead vysokokremnezemistogo zeolite powder in H-type form using HZSM-5 crystalline aluminosilicate powder with a Beta structure in the H form (molar ratio SiO ₂ / Al ₂ O ₃ = 75). The last portion (in example 3, it was 13 ml) of distilled water (pH = 6.6) was added to the paddle mixer very slowly until sufficient mass plasticity was obtained for extrusion in the syringe. After that, distilled water is no longer added. The mass is mixed for another 15-20 minutes at a temperature of 20 ° C and a wet mixture is passed at least 2 times through a device for grinding materials.

From the obtained plastic mass of the composition,% wt. (on a “dry” basis): 56.8% SMS-4 metal oxide catalyst, 24.4% Beta and 18.8% binder component in terms of Al ₂ O ₃ , at a temperature of 20 ° С, BFK extrudates are formed using a syringe on die with a hole diameter of 3 mm. The extrudates are dried in air for 48 hours and dried in an oven at a temperature of 120 ° C for 4 hours.

The prepared extrudates of universal BFK are examined for catalytic activity in the conversion of synthesis gas in a flow-type laboratory apparatus with circulation of a gas stream after condensation of liquid products. For research, a catalyst fraction of 0.25-0.5 mm is prepared and loaded into a laboratory reactor in an amount of 33 cm ³ .

The universal BFK calcination procedure is performed after loading a catalyst fraction of 0.25-0.5 mm into a fixed-bed synthesis gas conversion reactor, initially in a stream of nitrogen at a temperature of 200-320 ° C, then in a stream of synthesis gas at a temperature of 320-400 ° C in circulating conditions with a multiplicity of circulation of about 25.

The experiments are carried out at a pressure of 8 MPa and an average temperature in the catalyst layer of 400 ° C while passing synthesis gas mixed with circulating gas through a BFK layer.

A synthesis gas containing (in% vol.): 63.7% H ₂ , 33.7% CO, 0.1% CO ₂ , 1.5% N ₂ and 1.0% CH ₄ , is fed to the plant with volumetric speed of 630 h ^-1 , where it is mixed with the circulating gas before entering the reactor with a circulation ratio of 20. The gas-vapor stream after contacting with the universal BFK is cooled and the liquid products are separated in the separator from the gas phase. Liquid products are separated into a gasoline fraction and methanol water, partially separating CO ₂ and C ₃ -C ₄ hydrocarbons dissolved in them. To prevent the accumulation of methane and light hydrocarbons, part of the gas stream after the separator is constantly removed from the circulation circuit in the form of purge gas, and the main gas stream is mixed with the original synthesis gas and fed to the hydrocarbon synthesis reactor.

As a result of the conversion of synthesis gas, a CO conversion of about 88% was achieved, the selectivity for the formation of C ₅₊ hydrocarbons was 78% wt. the amount of hydrocarbons formed with an aromatic hydrocarbon content of 29% wt. in the C ₅₊ hydrocarbon fraction. In the resulting aromatic hydrocarbons, about 50% wt. make up C ₁₀₊ polymethylbenzenes, mainly tetramethylbenzenes. The benzene content in liquid hydrocarbons did not exceed 0.5% wt. The concentration of methanol in the aqueous fraction of liquid products was equal to 4.2% wt.

Example 18 (for comparison). This example shows the use of universal BFK not in optimal conditions for the conversion of synthesis gas with a high hydrogen content. The initial synthesis gas composition (vol.%): 68.1% H ₂ , 26.7% CO, 0.4% CO ₂ , 1.8% CH ₄ and 3.0% N ₂ are fed to the factory pilot plant with a volumetric rate of 1000 h ^-1 per loaded BFK consisting of a high silica zeolite HZSM-5 (molar ratio SiO ₂ / Al ₂ O ₃ = 70) and a metal oxide component containing metal oxides in a mass ratio of ZnO / Cr ₂ O ₃ / W ₂ O ₅ = 67/32/1, into the reactor block for mixing with the gas circulating in the block. The pilot plant is designed for testing BFK conversion of synthesis gas to liquid hydrocarbons in the factory.

Universal BFK industrial granulation is prepared by tabletting on a laboratory tablet machine. The size of the cylindrical tablets BFK is 3 × 4 mm. The amount of prepared BFC is 0.012 m ³ , which is two loads into a shelf adiabatic reactor. Before loading onto the shelves of the adiabatic reactor, BFK is sieved from fine crumbs and purged from catalyst dust. The loading of the catalyst on the reactor shelves is carried out using a special loading device so that the tablets are distributed strictly evenly over the diameter and height of the reactor shelves.

The reactor unit of the pilot installation consists of a shelf adiabatic reactor with the introduction of cold gas flows between the shelves, a condenser refrigerator, high and low pressure separators, an intermediate collector of liquid products and a gas compressor for gas circulation. The twin type adiabatic reactor has a maximum volume of about 0.006 m ^{3 of} charged catalyst.

The process of producing liquid hydrocarbons from factory synthesis gas (functional f = 2.5) used for the methanol synthesis process is conducted under a pressure of 8 MPa at an average temperature in the BFK layer of 360 ° C. To prevent the accumulation of non-condensable products and nitrogen in the reactor block, part of the reaction gas is constantly withdrawn from the block after the high-pressure separator. Liquid products (gasoline fraction, water + methanol), gas discharged from the reactor block and gaseous hydrocarbons (tank gases) released during throttling are analyzed separately by gas chromatography.

As a result of the conversion of synthesis gas after 600 hours of pelletized BFK run, the CO conversion was 88%, and the H ₂ conversion was about 72%. The selectivity of the formation of C ₅₊ hydrocarbons was about 80% wt. the amount of hydrocarbons formed with an aromatic hydrocarbon content of 3% wt. in the C ₅₊ hydrocarbon fraction. Benzene was practically absent in liquid hydrocarbons. The concentration of methanol in the aqueous fraction of liquid products was <3% wt. The performance of the universal BFK reached 85 g of gasoline / l of catalyst / h. After stabilization of the product, the octane number of gasoline did not exceed 82 IM.

The low content of aromatic hydrocarbons (only 3% by weight in the C ₅₊ hydrocarbon fraction) is associated with a high functionality of the initial synthesis gas (f = 2.5), a significant accumulation of hydrogen in the circulating gas and a low average temperature in the adiabatic reactor of 360 ° С .

The presented examples 2-7, 9, 11-17 illustrate in detail the solution to the problem of the present invention with obtaining a technical result, which consists in developing a method for preparing a durable and active universal BFK for the process of selective conversion of synthesis gas to gasoline fractions (at least 75% wt. C ₅₊ hydrocarbons per amount of hydrocarbons) with a moderate aromatic hydrocarbon content (15-35% wt.), not exceeding the permissible values in gasolines of ecological classes Euro-4, Euro-5 and Euro-6, as well as the use of this uni versal BFC for the processes of alkylation of aromatic hydrocarbons with synthesis gas, methylation of liquid olefins with products of conversion of synthesis gas, oligomerization of gaseous olefins and aromatization of liquid n-paraffins in a synthesis gas medium.

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Claims (6)

1. A method of preparing a universal bifunctional catalyst for converting synthesis gas and hydrocarbons into gasoline fractions, comprising separately grinding the components of a metal oxide catalyst for methanol synthesis, namely zinc and chromium oxides or zinc, chromium and aluminum oxides with an atomic ratio of Zn / Cr of less than 4, and zeolite component with a molar ratio of SiO ₂ / Al ₂ O _{3 of} more than 12, having micropores with a size of more than 0.5 nm, mixing the milled components of the metal oxide catalyst for methanol synthesis and the zeolite component to half teaching a homogeneous mixture, adding alumina as a binder to the mixture, granulating the resulting mixture by extrusion, drying the manufactured extrudates in air, crushing the extrudates to form granules of the catalyst composition and calcining the latter, characterized in that they take the reduced metal oxide catalyst for the synthesis of methanol with oxides sodium and iron less than 0.04 wt.% each, which has a 100% degree of recovery and was not exposed to temperatures above 400 ° C in air , Reducing or inert atmosphere, the acid component and the content of sodium oxide is less than 0.04 wt.%, Selected from a number of zeolites with the structure of ZSM-5, ZSM-12, Beta, having a molar ratio SiO ₂ / Al ₂ O ₃ more than 25, or from a number of crystalline silicoaluminophosphates with the SAPO-5 structure, or a combination of SAPO-5 with a zeolite of the ZSM-5 type, grind them to a particle size of less than 0.3 mm, add an active alumina hydrogel or amorphous hydroxide as a binder component aluminum and, if necessary, chemically purified water with pH 6.5-7.5, while in the reduced metal oxide catalyst for methanol synthesis, in acidic and in binder components there should be no water-soluble metal cations and anions of inorganic and organic acids, and the pH of the components of the bifunctional catalyst should be in the range of 6.5 -7.5, after which the pasty mass obtained by mixing the particles of the reduced metal oxide catalyst for the synthesis of methanol, acid and binder components at a temperature of 20-60 ° C is passed at least twice a cutting device for grinding materials, in which the cutting unit consists of a rotating figure knife that interacts with a fixed grid with through axial channels, and then is subjected to screw or piston extrusion at a temperature of 20-60 ° C, and the obtained extrudates are dried in two stages: first at room temperature for at least 24 hours, and then at a temperature of 120 ° C for at least 4 hours, while the granules formed as a result of crushing the dried extrudates should have a cylindrical a mold with a diameter of 3-5 and a length of 8-12 mm, and the granules are calcined after they are loaded into the synthesis gas conversion reactor with a fixed catalyst bed: initially, at a temperature of 200-320 ° C in nitrogen, and then at a temperature of 320-400 ° C in a circulating synthesis gas medium, while the multiplicity of the synthesis gas circulation should be at least 10. 2. The method according to p. 1, characterized in that as the binder component is used active hydrogels of aluminum oxide - pseudoboehmite, or thermochemically activated aluminum hydroxide, or reprecipitated aluminum hydroxide with a content of sodium, potassium and calcium oxides of less than 0.03 wt.% Each based on the dry weight of the binder component. 3. The method according to p. 1, characterized in that the content of the binder component in the bifunctional catalyst, based on dry Al ₂ O ₃ , is from 10 to 20 wt.%. 4. The method according to p. 1, characterized in that the reduced metal oxide catalyst for the synthesis of methanol contains tungsten in an amount of not more than 1 wt.% As a promoting additive. 5. The method according to p. 1, characterized in that the zeolite with a structure of ZSM-5, which is part of a bifunctional catalyst, contains iron in an amount of from 0.1 to 1 wt.%, Which is introduced into the crystalline structure of the zeolite at the stage of hydrothermal synthesis. 6. The method according to p. 1, characterized in that the cylindrical granules after calcination are crushed, and then subjected to run-in in a drum device to form granules of a catalytic composition having a spherical shape with a diameter of 0.1-2.0 mm

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