RU2768115C1 - Catalyst and method for production thereof - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a catalyst and a method of producing a catalyst for producing gasolines during combined processing of hydrocarbon fractions, oxygenates and olefin-containing fractions. Catalyst contains zeolite ZSM-5 in amount of 50.0 to 85.0 wt.%, where: a. pore volume of the catalyst ranges from 0.15 to 0.26 cm³/g, b. average pore diameter of the catalyst ranges from 38 to 53 Å, c. ratio of weak and strong acid sites of the catalyst ranges from 2.2 to 3.5, wherein the catalyst contains, in terms of chemical composition, in terms of oxides: d. silicon dioxide in amount of 53.0 to 85.0 wt.%, e. aluminum oxide in amount of 10.9 to 43.0 wt.%, f. boron oxide in amount of 0.5 to 2.5 wt.%, g. zinc oxide in amount of 1.4 to 2.9 wt.%, h. oxides of rare-earth elements in amount of 0.9 to 2.0 wt.%. Method of producing catalyst includes: mixing HZSM-5 and peptized pseudoboehmite, adding boric acid, adding silica sol with pH 8–10 to obtain molding compound, molding, drying and calcination of the molding compound to obtain a catalyst composition, alkaline treatment, washing from sodium, drying and calcining the catalyst composition, impregnating the catalyst composition with solutions of zinc salts and rare-earth elements, drying and calcining.

EFFECT: interregeneration period of catalyst operation is not less than 480 hours, simultaneous increase in output of C₅₊ hydrocarbons and product RON.

10 cl, 5 tbl, 18 ex

Description

The invention relates to the field of oil refining and petrochemical industry. More specifically, the invention relates to a catalyst for the production of gasolines and a method for producing the catalyst. The proposed catalyst is particularly effective for the processes of joint processing of hydrocarbon fractions, oxygenates and olefin-containing fractions.

BACKGROUND OF THE INVENTION

Joint processing of hydrocarbon fractions, oxygenates and olefin-containing fractions makes it possible to produce a high-octane base of motor gasolines from low-cost raw materials. A number of zeolite catalysts are known for processing oxygenates, hydrocarbon fractions or mixtures thereof into gasoline components. However, such catalysts are quickly deactivated when little-demanded olefin-containing fractions, such as catalytic cracking gases, are added to the feedstock. This leads to a decrease in the inter-regeneration period of the catalyst, and reduces the economic attractiveness of joint processing. This problem necessitates the development of a zeolite catalyst adapted to work under conditions of co-processing (processing of mixtures of hydrocarbon fractions, oxygenates and olefin-containing fractions), and a method for preparing such a catalyst.

WO 2017155431 describes a process for the production of gasoline from mixtures of hydrocarbon fractions, gaseous olefin fractions and oxygenates. A variant of the invention is described in which a zeolite-containing catalyst is used, where a synthetic amorphous aluminosilicate or an inorganic oxide is used as a binder, which is a mixture of 30-70 wt. % aluminum oxide and 70-30 wt. % silicon oxide. Described is a catalyst for producing liquid hydrocarbons from dimethyl ether, including a crystalline aluminosilicate of the pentasil type: 63-69.8 wt. %, zinc oxide: 0.5-3.0 wt. %; oxides of rare earth elements: 0.1-5.0 wt. %, cobalt oxide: 0.05-2.5 wt. %, binder: the rest. The document does not consider the influence of the original components of the binder on the catalytic properties of the catalyst. The problem of replacing the alkaline treatment of the zeolite with the alkaline treatment of catalyst pellets, and the possible consequences of such a replacement, are not described. The effect of the acidic and textural properties of the catalyst on the inter-regeneration period of the catalyst operation is not considered. The problems arising from the introduction of boric acid into the combined binder of the zeolite catalyst, and ways to solve them, are not considered.

RU 2658832 describes a catalyst for the conversion of hydrocarbons, alcohols, ethers or mixtures of alcohols and ethers. The catalyst contains zeolite ZSM-5 or ZSM-11 with a molar ratio of SiO ₂ /Al ₂ O ₃ =20-150 mol/mol and a residual sodium oxide content of not more than 0.4 wt. %, zinc oxide and/or gallium oxide, lanthanum oxide, binder (gamma - Al ₂ O ₃ , and/or silicon dioxide, and/or synthetic aluminosilicate, and/or clay, and/or zirconium dioxide and others) and oxide strontium, and the content of strontium oxide in the composition of the catalyst is from 0.01 to 3.0 wt. %, the zeolite content is from 20.0 to 90.0 wt. %, the content of zinc oxide is from 0.1 to 6.0 wt. %, the content of gallium oxide is from 0.1 to 3.0 wt. %, the content of lanthanum oxide (La ₂ O ₃ ) is from 0.1 to 5.0 wt. %, the content of the binder component - the rest up to 100 wt. %. A variety of optional catalyst components are also provided. The document assumes the use of strontium compounds for the preparation of a catalyst, which complicates industrial production (taking into account acute toxicity, explosiveness, and fire hazard of such raw materials). No mention is made of the consequences of the use of a catalyst for the processes of co-processing of hydrocarbon fractions, oxygenates and olefin-containing fractions. Based on the description of the document, the composition of the binder does not affect the achieved result: the use of any of dozens of binder options (gamma - Al ₂ O ₃ and / or silicon dioxide, and / or synthetic aluminosilicate, and / or clay, and / or zirconium dioxide and others) lead to similar results. Alkaline processing is not considered. The effect of the acidic and textural properties of the catalyst on the inter-regeneration period of the catalyst operation is not considered. The problems arising from the introduction of boric acid into the combined binder of the zeolite catalyst, and ways to solve them, are not considered.

EA 201891760 describes a catalyst for the co-conversion of hydrocarbon fractions and oxygenates into high-octane fuel components or aromatic hydrocarbons. This catalyst is considered as the closest to the present invention and is taken as a prototype. Described is a catalyst containing zeolite HZSM-5 with a silicate module SiO ₂ /Al ₂ O ₃ =50-81.9, with a residual amount of sodium oxide of 0.04-0.15 wt. %, subjected to thermocouple treatment to the stage of preparation of the catalyst, in the amount of 65-69.8 wt. %, zinc oxide in the amount of 1.5-2 wt. %, oxides of rare earth elements in the amount of 1-2 wt. %, oxides and/or sulfides of Group VIII metals in the amount of 0.5-1 wt. %, binder - the rest up to 100%, while a mixture of aluminum oxide is used as a binder - 30.1-69.9 wt. %, and silicon oxide - 69.9-30.1 wt. %. The document proposes to carry out the thermosteam treatment of the zeolite, which complicates the industrial production of the catalyst (the need to use specialized equipment). No mention is made of the consequences of the use of a catalyst for the processes of co-processing of hydrocarbon fractions, oxygenates and olefin-containing fractions. The problem of replacing the alkaline treatment of the zeolite with the alkaline treatment of the catalyst pellets and the consequences of such a change have not been described. The effect of the acidic and textural properties of the catalyst on the inter-regeneration period of the catalyst operation is not considered. The problems arising from the introduction of boric acid into the combined binder of the zeolite catalyst, and ways to solve them, are not considered.

DISCLOSURE OF THE INVENTION

It was found that a catalyst for the production of gasoline, including zeolite ZSM-5, is especially effective for the co-processing of hydrocarbon fractions, oxygenates and olefin-containing fractions with the following combination of acidic and textural properties of the catalyst:

• the pore volume of the catalyst is from 0.15 to 0.26 cm ³ /g,

• the average pore diameter of the catalyst is from 38 to 53 Å,

• the ratio of weak and strong acid sites of the catalyst is from 2.2 to 3.5.

The present invention also provides a method for preparing a catalyst that achieves the specified combination of acidic and textural characteristics of the catalyst.

The main technical result is the achievement of an inter-regeneration period of catalyst operation of at least 480 hours under conditions of joint processing. Also achieved is a simultaneous increase in the yield of C ₅₊ hydrocarbons and the ROI of the C ₅₊ fraction of the hydrocarbon product.

The above technical results are achieved by the proposed catalyst for the production of gasoline, including zeolite ZSM-5 in an amount of from 50.0 to 85.0 wt. %, where:

a. the pore volume of the catalyst is from 0.15 to 0.26 cm ³ /g,

b. the average pore diameter of the catalyst is from 38 to 53 Å.

c. the ratio of weak and strong acid sites of the catalyst is from 2.2 to 3.5,

moreover, the catalyst includes, by chemical composition, in terms of oxides:

d. silicon dioxide in an amount from 53.0 to 85.0 wt. %,

e. aluminum oxide in an amount from 10.9 to 43.0 wt. %,

f. boron oxide in an amount of 0.5 to 2.5 wt. %,

g. zinc oxide in an amount of 1.4 to 2.9 wt. %,

h. oxides of rare earth elements in an amount of 0.9 to 2.0 wt. %.

It is possible to carry out the invention in which the catalyst is used for the co-processing of hydrocarbon fractions, oxygenates and olefin-containing fractions into gasolines, preferably the catalyst is used for a method for producing gasolines, in which three streams are used as feedstock, one of which includes a hydrocarbon fraction, the second stream includes oxygenate, the third stream includes an olefin-containing fraction, where the olefin-containing fraction includes one or more olefins selected from the group including: ethylene, propylene, normal butylenes, isobutylene, in a total amount of from 10.0 to 50.0 wt. %.

It is possible to carry out the invention, in which the rare earth elements include one or more elements selected from the group including: lanthanum, praseodymium, neodymium, cerium.

It is possible to execute the invention, in which the catalyst does not contain one or more elements selected from the group including: platinum metals, iron, cobalt, nickel.

It is possible to carry out the invention, in which the zeolite has a silica module SiO ₂ /Al ₂ O ₃ in the range from 50 to 90, preferably from 60 to 80.

The above technical results are also achieved through the proposed method for producing a catalyst, which includes the following stages:

a. adding HZSM-5 to peptized pseudoboehmite to obtain a mixture of zeolite and pseudoboehmite,

b. adding boric acid to a mixture of zeolite and pseudoboehmite,

c. adding silica sol with a pH of 8-10 to the mixture obtained in step (b) to obtain a molding composition,

d. molding, drying and calcining the molding mass to obtain a catalyst composition,

e. alkaline treatment of the catalyst composition obtained in step (d),

f. washing the catalyst composition obtained in step (e) from sodium, drying and calcining,

g. impregnation of the catalyst composition obtained in step (f) with solutions of zinc and rare earth salts, drying and calcination.

It is possible to carry out the invention, in which an aqueous solution of alkali with a pH of 10 to 14, preferably a pH of 12 to 14, is used for alkaline treatment.

It is possible to execute the invention, in which an aqueous solution of sodium hydroxide with a concentration of 0.01-0.5 M is used for alkaline treatment.

It is possible to execute the invention, in which the alkali treatment is carried out by heating up to 30-80°C.

It is possible to carry out the invention in which the impregnation of the catalyst composition is carried out using moisture capacity impregnation or impregnation in excess solution.

IMPLEMENTATION OF THE INVENTION

CATALYST

The textural properties of the catalyst samples (including the pore volume and pore size distribution) were determined by the low-temperature nitrogen adsorption method. The pore volume was determined from the desorption curve. Pore size distribution curves were calculated using the BJH method.

The acid properties of the catalyst samples (including the ratio of weak and strong acid sites) were determined by the method of thermally programmed ammonia desorption (TPD NH ₃ ). At the same time, the TPD profiles of NH ₃ for the catalysts according to the invention include two pronounced peaks:

• low-temperature peak of desorption of ammonia from weak acid centers and acid centers of medium strength, T _max(I) =170-190°C,

• high-temperature peak of desorption of ammonia from strong acid sites,

_Tmax(II) =365-390°C.

The ratio between weak and strong acid sites (µmol/g: µmol/g) is defined as the ratio of Low temperature peak, µmol/g to High temperature peak, µmol/g.

Catalyst pore volume

The developed catalyst has a relatively low pore volume (0.15 to 0.26 ^cm3 /g). Known sources usually recommend the use of catalysts with increased pore volume, in particular catalysts with a pore volume of more than 0.3 cm ³ /g, incl. more than 0.6 cm ³ /g. However, it was found that when trying to create a catalyst with a ratio ^of weak and strong acid sites from 2.2 to 3.5, an increase in the pore volume above 0.26 cm As a result, the interregeneration period of the catalyst operation is reduced. This is unexpected, since increasing the pore volume of the catalyst is generally recommended to increase the regeneration period. It was noted that both an increase in the pore volume of the catalyst above 0.26 cm ³ /g and a decrease in the pore volume of the catalyst below 0.15 cm ³ /g lead to a decrease in the interregeneration period of the catalyst from more than 450 hours to 200-350 hours.

Catalyst average pore diameter

It was found that when trying to create a catalyst with a pore volume from 0.15 cm ³ /g to 0.26 cm ³ /g, an increase in the average pore size above 53 Å leads to an undesirable increase in the production of C ₁₁₊ aromatics in coprocessing processes. At the same time, a decrease in the average pore diameter below 38 Å leads to an undesirable increase in the selectivity for the formation of methane and C ₂ -C ₄ olefins.

The influence of the combination ^of the catalyst pore volume from 0.15 to 0.26 cm3/g, the average pore size from 38 to 53 Å, and the ratio of weak and strong acid sites of the catalyst is from 2.2 to 3.5 on the regeneration period of the catalyst operation is probably associated with the introduction of low-demand olefin-containing fractions in the process of joint processing.

Such olefin-containing fractions include C ₂ -C ₄ olefins in an amount of from 10 to 50 wt. %. This content of olefins does not allow the use of these fractions in classical petrochemical processes without additional preparation and concentration. It has been found that the addition of C ₂ -C ₄ olefins to the coprocessing process can accelerate coking compared to olefins released from oxygenates during the conversion process. Previously known catalysts based on zeolites solved the problem of the presence of oxygenates in the feedstock (including the resistance of the catalyst to water vapor). However, the addition of dilute C ₂ -C ₄ olefins to the feed creates new coking problems and reduces the regeneration time for known catalysts.

For example, the use of a reference catalyst (composition: HZSM-5 zeolite with a silicate module SiO ₂ /Al ₂ O ₃ = 81.9:69.8 wt.%, zinc oxide 2 wt.%, REE oxides 1.5 wt.%, nickel oxide 0.5 wt. %, binder (a mixture of alumina 50 wt. % and silicon oxide 50 wt. %), the rest up to 100%), under the conditions of example 10, leads to a decrease in the regeneration period of the catalyst to 340 hours (compared to 480 hours for the catalyst of the invention according to example 10, see Table 5). When nickel is replaced by cobalt in the composition of the reference catalyst, similarly low values of the interregeneration period (311 hours) are obtained.

The ratio of weak and strong acid sites

It was found that the ratio of weak and strong acid sites makes it possible to control the selectivity of the catalyst to the formation of C ₅₊ hydrocarbons. At the same time, the maximum yield of C ₅₊ hydrocarbons in the processes of joint processing is observed at a ratio between weak and strong acid sites (µmol/g : µmol/g) of the catalyst in the range of 2.2–3.5.

The use of catalysts with a ratio between weak and strong acid sites of less than 2.2 reduces the yield of C ₅₊ hydrocarbons to less than 65 wt. % for supplied hydrocarbon feedstock. At the same time, the use of catalysts with a ratio between weak and strong acid sites in the range of 3.6–6.5 does not allow the RON of the product to exceed 90 units. while maintaining the product yield of more than 65 wt. %.

An increase in the selectivity of formation of hydrocarbons С ₅₊ with the recommended combination of pore volume and acidity may be associated with a decrease in the selectivity of formation of methane and olefins С ₂ -С ₄ . In particular, when using the proposed catalyst, the amount of methane in the gaseous reaction products is reduced to less than 1.0 wt. %, the amount of olefins C ₂ -C ₄ in the gaseous reaction products is reduced to trace amounts (less than 0.5 wt. %).

Catalyst Composition

The proposed catalyst includes, by chemical composition, in terms of oxides:

• silicon dioxide in an amount of 53.0 to 85.0 wt. %,

• aluminum oxide in the amount of 10.9 to 43.0 wt. %,

• boron oxide in an amount of 0.5 to 2.5 wt. %,

• zinc oxide in an amount of 1.4 to 2.9 wt. %,

• oxides of rare earth elements in an amount of 0.9 to 2.0 wt. %.

In this case, the catalyst includes, in terms of phase composition, ZSM-5 zeolite in an amount of from 50.0 to 85.0 wt. %, as well as a binder and promoters. The chemical composition of the catalyst, wt. % and the proportion of zeolite in the catalyst, wt. %, non-additive (do not add up to 100 wt. %), since the proportion of zeolite refers to the phase composition of the catalyst.

- Binder. The proposed catalyst includes a binder, including the chemical composition, in terms of oxides, a mixture of SiO ₂ and Al ₂ O ₃ (combined binder). However, the proportion and, in particular, the chemical composition of such a binder cannot, as a rule, be unambiguously determined in a zeolite catalyst sample by experimental methods. In this regard, the present invention limits the proportion and chemical composition of the binder through the proposed combination of the chemical composition of the catalyst and the proportion of zeolite in the catalyst, which can be determined in the finished sample of the catalyst by experimental methods.

In particular, in the following examples 1-7 according to the invention, the catalyst comprises from 50.0 to 85.0 wt. % zeolite ZSM-5, where the rest is up to 100 wt. % falls on the binder and promoters. The share and chemical composition of the binder in the finished samples of the catalyst is not determined experimentally. The estimated content of the binder in the catalysts for examples 1-7 is 10.9-46.0 wt. % by weight of the catalyst. The calculated chemical composition of the binder, in the catalysts according to examples 1-7, in terms of oxides of SiO ₂ and Al ₂ O ₃ is 7.9-51.8 wt. % silicon oxide and 48.2-92.1 wt. % aluminum oxide by weight of the binder.

- Promoters - compounds of rare earth elements, alkali metals, alkaline earth metals, metals of groups III - VIII A/B), preferably boron oxide, zinc oxide, lanthanum oxide, cerium oxide, praseodymium oxide, neodymium oxide.

It is possible to execute the invention, in which the catalyst does not contain one or more elements selected from the group including: platinum metals, iron, cobalt, nickel. Given the different sensitivity of analytical chemistry methods to the determination of metal content, the term "does not contain" means that the total content of iron, cobalt, nickel in the catalyst does not exceed 0.10 wt. %, preferably does not exceed 0.05 wt. %, most preferably does not exceed 0.01 wt. %.

The catalyst may include impurity amounts of sodium oxide, for example, from 0.01 to 0.15 wt. % sodium oxide.

ZSM-5 zeolites are generally characterized by modulus (molar ratio of SiO ₂ /Al ₂ O ₃ ). The proposed method of catalyst preparation allows the use of zeolites with a wide range of modules, in particular, it is possible to use a zeolite with a SiO ₂ /Al ₂ O ₃ module in the range of 30-120, preferably 50-90, most preferably 70-80.

The chemical composition of zeolite catalysts is usually given based on the catalyst calcined at a certain temperature. In particular, for the catalysts according to examples 1-9, the chemical composition of the catalyst, wt. %, in terms of oxides, is given for samples calcined at 550°C. This calcination temperature is not related to the calcination operations carried out in the catalyst preparation process, and refers to the calcination of the catalyst in order to determine its chemical composition by analytical chemistry methods, in particular to remove sorbed moisture.

It was found that the compliance of the catalyst with the specified requirements for the phase and chemical composition does not in itself guarantee that the catalyst has the proposed combination of texture and acid characteristics (the pore volume ^of the catalyst is 0.15–0.26 cm3/g, the average pore diameter of the catalyst is 38–53 Å, the ratio of weak and strong acid sites of the catalyst 2.2-3.5).

In particular, the comparison catalyst according to example 8 corresponds to the characteristics of the proposed catalyst in terms of chemical and phase composition (see Table 2). However, the reference catalyst of Example 8 achieves the combination of pore volume, average pore diameter, and weak/strong acid site ratio of the catalyst of the invention (see Table 2). In particular, the reference catalyst of Example 8 shows too low a pore volume (0.12 cm ³ /g) and a reduced ratio between weak and strong acid sites (1.2). As a result, the interregeneration period of the catalyst is sharply reduced to 240 hours, while it is not possible to achieve a product yield of more than 65 wt. % while maintaining the product ROI more than 90 units. (see Table 5, example 17, use of the catalyst according to comparative example 8).

Boron oxide

The proposed catalyst includes, by chemical composition, in terms of oxides, boron oxide in an amount of from 0.5 to 2.5 wt. %. Operation in this range allows one to simultaneously increase the yield of C ₅₊ hydrocarbons and the RON of the product (compared to a catalyst that did not use boric acid). In particular, an increase in the yield of the C ₅₊ fraction of the product from 56 wt. % up to 65 wt. % (see below example 10 according to the invention and example 18 using the catalyst of comparison 9, in the preparation of which boric acid was not used, Table 5). This increases the RON of the product from 91 to 92. As a result, the unusual effect of simultaneously increasing the yield and octane number of the liquid product is achieved. When using boron oxide in an amount of less than 0.5 wt. % or more than 2.5 wt. %, achieving the yield of the C ₅₊ fraction of the product is accompanied by an undesirable decrease in the RON of the product below 88.

However, it has been found that the modification of a zeolite catalyst with boron compounds can lead to a sharp drop in the stability of the catalyst under conditions of joint processing of hydrocarbon fractions, oxygenates, and olefin-containing fractions. In particular, Comparative Example 8 demonstrates that the use of a catalyst corresponding to the chemical composition

a. silicon dioxide in an amount from 53.0 to 85.0 wt. %,

b. aluminum oxide in an amount from 10.9 to 43.0 wt. %,

c. boron oxide in an amount of 0.5 to 2.5 wt. %,

d. zinc oxide in an amount of 1.4 to 2.9 wt. %,

e. oxides of rare earth elements in an amount of 0.9 to 2.0 wt. %.

can dramatically reduce the interregeneration period of the zeolite catalyst from more than 480 hours to 240 hours under co-processing conditions (see example 17 below, Table 5). The problem can be solved by using a combination of a pore volume of the catalyst from 0.15 to 0.26 cm ³ /g, an average pore size of 38 to 53 Å, and the ratio of weak and strong acid sites of the catalyst is from 2.2 to 3.5, which, in particular, shows a comparison examples 10 and 17 (see Tables 2 and 5).

METHOD FOR PRODUCING A CATALYST

To obtain a catalyst according to the proposed method, the following steps are carried out:

a. adding HZSM-5 to peptized pseudoboehmite to obtain a mixture of zeolite and pseudoboehmite,

b. adding boric acid to a mixture of zeolite and pseudoboehmite,

c. adding silica sol with a pH of 8-10 to the mixture obtained in step (b) to obtain a molding composition,

d. molding, drying and calcining the molding mass to obtain a catalyst composition,

e. alkaline treatment of the catalyst composition obtained in step (d),

f. washing the catalyst composition obtained in step (e) from sodium, drying and calcining,

g. impregnation of the catalyst composition obtained in step (f) with solutions of zinc and rare earth salts, drying and calcination.

Stage (a)

Peptized pseudoboehmite and HZSM-5 are mixed. Optionally, the mixture is evaporated with stirring to a pasty consistency. The result is a mixture of zeolite and pseudoboehmite. Wherein:

- HZSM-5 (zeolite ZSM-5 in H-form) can be obtained by already known methods, for example, by ion exchange of the sodium form of the ZSM-5 zeolite to obtain the ammonium form of the zeolite, and subsequent calcination of the ammonium form of the zeolite to obtain the ZSM-zeolite 5 in H-form. Optionally, the zeolite may be dried and/or calcined and/or milled before mixing. HZSM-5 may contain trace amounts of sodium.

The peptized pseudoboehmite can be obtained by known methods, for example by treating a powder or pellet of pseudoboehmite with an aqueous solution of an inorganic acid, preferably nitric acid. Pseudoboehmite (aluminum hydroxide with a pseudoboehmite structure) is commercially available.

- Optionally, peptized pseudoboehmite can be obtained from thermally activated aluminum hydroxide (TCA product). At the same time, the preparation of peptized pseudoboehmite may include the stages of washing from sodium, autoclaving, hydration, the procedure for which may differ depending on the configuration of the equipment of a particular production. This design allows to achieve an additional technical result: to increase the mechanical strength of the catalyst, and the losses of the catalyst during production, caused by the production of catalyst particles with a size of less than 1 mm, are reduced.

- Optionally, peptized pseudoboehmite can be obtained from thermally activated aluminum hydroxide, where the process for obtaining pseudoboehmite includes the following steps:

a. hydration of thermally activated aluminum hydroxide at a molar ratio of nitric acid/alumina 0.01 to 0.02;

b. washing from sodium suspension obtained in stage (a);

c. treatment of the suspension obtained in step (b) in an autoclave at a molar ratio of nitric acid/alumina from 0.10 to 0.20.

- Optionally, peptized pseudoboehmite can be obtained from thermally activated aluminum hydroxide, where the process for obtaining pseudoboehmite includes the following steps:

a. washing thermally activated aluminum hydroxide from sodium;

b. treatment of the suspension obtained in step (b) in an autoclave at a molar ratio of nitric acid/alumina from 0.01 to 0.02;

from. hydration of the suspension obtained in stage (b) at a molar ratio of nitric acid/alumina from 0.10 to 0.20.

Step (b)

Boric acid is added to the mixture of zeolite and pseudoboehmite obtained in step (a).

- Boric acid is used in the form of an aqueous solution of boric acid. An aqueous solution of boric acid can be prepared by already known methods, while such parameters as the mass of boric acid, the amount of water, the temperature for preparing the solution can be selected by the operator based on the characteristics of a particular production based on reference data.

- When determining the amount of boric acid added to a mixture of zeolite and pseudoboehmite, the content of boron oxide in the resulting catalyst, in terms of chemical composition, in terms of oxides (from 0.5 to 2.5 wt.%) is important.

The proposed catalyst contains a zeolite and a combined binder, where sources of alumina and silicon oxide are used in the preparation of the binder. Cases of using boric acid in the preparation of zeolite catalysts are known. However, it was found that the use of boric acid in the preparation of a zeolite catalyst with a combined binder leads to a sharp drop in the stability of the catalyst under conditions of joint processing of hydrocarbon fractions, oxygenates, and olefin-containing fractions. In particular, Comparative Example 8 below demonstrates that the addition of boric acid to a binder based on a mixture of SiO ₂ and Al ₂ O ₃ can dramatically reduce the turnaround time of a zeolite catalyst from over 480 hours to 240 hours under coprocessing conditions (see Tables 1 and 5).

This problem was solved by alkaline treatment of the catalyst composition. It was found that the simultaneous use of boric acid and alkaline treatment of the catalyst composition allows:

• to increase the inter-regeneration period of the catalyst (compared to the catalyst, where boric acid was used, but the catalyst composition was not subjected to alkaline treatment). In particular, the inter-regeneration period is increased from 240 hours (cf. example 8) to 480 hours (example 1);

• increase the yield of C ₅₊ hydrocarbons and the RON of the product (compared to a catalyst that did not use boric acid). In particular, the yield of C ₅₊ with 56 wt. % (compare example 9) up to 65 wt. % yield (example 1). The ROI of the product increases from 91 (comp. example 9) to 92 (example 1). This achieves the unusual effect of simultaneously increasing the yield and octane number of the liquid product. In known processes, an increase in the RON of the product is usually accompanied by a decrease in the yield of the liquid product, which was avoided under conditions of co-processing through the use of the proposed combination of features. Thus, the simultaneous use of boric acid and alkaline treatment of the catalyst composition makes it possible to achieve results that are not achieved with the individual use of each of the approaches.

In this case, the alkaline treatment step is important. Alkaline treatment of the original zeolite does not lead to the desired technical effects, in contrast to the alkaline treatment of the catalyst composition during the preparation of the catalyst.

Stage (s)

To the mixture of zeolite, pseudoboehmite and boric acid obtained in step (b) is added silica sol (colloidal silicon dioxide) with a pH in the range of 8 to 10. Optionally, the resulting mass is evaporated to formability. As a result, a molding mass is obtained. Wherein:

- The proposed method for producing a catalyst uses silica with a pH in the range from 8 to 10 units. The pH 8-10 of the original silica sol is one of the features that make it possible to achieve the optimal combination of the average pore size of the catalyst and its acidic properties in the method of obtaining the catalyst.

It was found that the use of silica sol with a pH of less than 8 leads to a sharp drop in the interregeneration period of operation of the resulting catalyst under conditions of joint processing to less than 250 hours. , show an interregeneration period of at least 480 hours. This result can be associated with an increase in the average pore size of the resulting catalyst when using silica sol with a pH of less than 8 units, which in turn changes the nature of coking. It was found that the use of silica sol with a pH of more than 10 leads to a decrease in the mechanical strength of the resulting catalyst.

- The proposed method for obtaining a catalyst involves a certain order of mixing the zeolite component and the initial components of the binder:

but. adding HZSM-5 to peptized pseudoboehmite to obtain a mixture of zeolite and pseudoboehmite,

b. adding boric acid to a mixture of zeolite and pseudoboehmite,

c. adding silica sol with a pH of 8-10 to the mixture obtained in step (b) to obtain a molding composition,

d. molding, drying and calcining the molding mass to obtain a catalyst composition.

It was found that the proposed order of mixing the components of the catalyst composition makes it possible to suppress the formation of a by-product aluminosilicate fraction of the binder. It was found that non-compliance with the recommended order of mixing components, for example, mixing zeolite, pseudoboehmite and silica sol in one stage, distorts the phase pattern of the final catalyst sample and changes the pore size distribution of the resulting catalyst.

Stage (d)

The molding mass obtained in step (c) is molded, dried and calcined. Optionally, the granules are dried before drying. The result is a catalyst composition. Wherein:

- Already known methods of shaping catalysts based on zeolites can be used, for example, extrusion molding, tableting.

- Temperature, temperature rise rate, duration of the withering (optional), drying and roasting operations may vary depending on the conditions of a particular production, and can be selected by already known methods in the course of routine experiments.

Stage (e)

The catalyst composition obtained in step (d) is subjected to an alkaline treatment. The result is a catalyst composition that has undergone alkaline treatment. Wherein:

- For alkali treatment, an alkali solution with a pH of 10 to 14 is used, preferably a pH of 12 to 14. Preferably, the alkali solution comprises an alkali or alkaline earth metal hydroxide, more preferably sodium hydroxide. Most preferably, an aqueous solution of sodium hydroxide with a concentration of 0.01 to 0.5 mol/l is used for alkaline treatment.

- Optionally, after treatment with an alkali solution, the catalyst composition is washed with water from alkali residues and dried. Optionally, it is possible to calcinate the catalyst composition after drying. Preferably, an excess of alkali solution is used for alkali treatment.

- Temperature, rate of temperature rise, duration of drying and calcining operations may vary depending on the conditions of a particular production, and can be selected by already known methods in the course of routine experiments.

The proposed method for producing a catalyst uses sources of SiO ₂ and Al ₂ O ₃ (silica sol and pseudoboehmite) for the preparation of a combined binder. It was found that alkaline treatment of a catalyst composition based on a zeolite and a combined binder makes it possible to increase the interregeneration period of catalyst operation:

• compared to no alkali treatment: from 230 to over 480 hours;

• compared to alkaline treatment of the original zeolite: from 390 to more than 480 hours.

Replacing the alkaline treatment of the original zeolite with alkaline treatment of the catalyst composition increases the regeneration period of the catalyst. This is surprising since known methods recommend alkaline treatment of the original zeolite prior to its mixing with the binder components. Replacing the alkaline treatment of the starting zeolite with the alkaline treatment of the catalyst composition is also advantageous from a commercial production point of view. Alkaline treatment of zeolite powder is associated with high technological losses of zeolite. Replacing alkali treatment of zeolite with alkali treatment of pellets simplifies catalyst production and reduces zeolite losses at the alkali treatment station.

Stage (f)

The catalyst composition obtained in step (e) is washed free of sodium, dried and calcined. Wherein:

- Washing from sodium can be carried out by ion exchange. Preferably, the catalyst composition is treated with an aqueous solution containing ammonium ions. Most preferably, the catalyst composition is treated with an aqueous solution of ammonium chloride or ammonium nitrate.

- Ion exchange methods are known in the field of zeolite catalysts. The amount of ammonium salt, water, the ratio of solid : liquid by weight, time and temperature of processing can be selected by known methods. Optionally, the ion exchange is carried out without stirring at room temperature. Optionally, it is possible to carry out repeated ion exchange and washing with water. Preferably, the final content of Na ₂ O in the catalyst composition does not exceed 0.15 wt. %.

- The temperature, the temperature rise rate, the duration of the drying and calcining operations may vary depending on the conditions of a particular production, and can be selected by known methods.

Stage (g)

The catalyst composition obtained in step (f) is impregnated with solutions of zinc and rare earth salts, dried and calcined. The result is a catalyst. Wherein:

- The impregnation can be carried out by known methods, for example by the method of impregnation according to the moisture capacity or by the method of impregnation in excess solution.

- Optionally, when impregnating by moisture capacity, the volume of the impregnating solution (V, ml) is calculated by the formula: V=B⋅m, where B is the moisture capacity of the carrier, ml/g, m is the mass of the carrier, g.

- Preferably, salts of inorganic acids are used as zinc salts, most preferably zinc nitrate.

- Preferably, salts of inorganic acids are used as salts of rare earth elements, most preferably nitrates of rare earth elements (REE). Preferably, the rare earth elements are selected from the group consisting of lanthanum, praseodymium, neodymium, cerium, and mixtures thereof.

- Optionally, an industrial REE concentrate can be used as a source of rare earth elements. Commercial REE concentrates usually contain mixtures of salts of rare earth elements, especially lanthanum and cerium. The use of commercial REE concentrates reduces the cost of industrial-scale production of catalysts.

- The temperature, the temperature rise rate, the duration of the drying and calcining operations may vary depending on the conditions of a particular production, and can be selected by known methods.

CATALYST APPLICATION

It is possible to use the proposed catalyst for the joint processing of hydrocarbon fractions, oxygenates and olefin-containing fractions.

Hydrocarbon fraction

Suitable hydrocarbon fractions are characterized by an end point of the boiling point of not more than 215°C. In particular, the end of the boil may be 200°C, 180°C, 160°C or 85°C. Preferably, the end point of the boil is at most 180°C. The end boiling point (End Boiling Point, °C) can be determined, for example, according to GOST 2177 or ASTM D 86.

The initial boiling point has little effect on the results achieved, in particular because hydrocarbon fractions, incl. oil fractions and semi-products of petrochemical industries may contain various amounts of dissolved gases C ₁ -C ₄ , depending on the internal requirements of industrial production. The initial boiling point of the hydrocarbon fraction may be, for example, 62°C, 85°C, 140°C. Preferably, the initial boiling point is not lower than 62°C.

The detailed hydrocarbon composition of the hydrocarbon fraction, for example, determined according to ASTM D 6729, has little effect on the ability to achieve technical results, incl. because a typical hydrocarbon fraction contains hundreds of individual chemicals. Table 3 lists special cases of the chemical composition of the hydrocarbon fractions used in examples 10-18. The hydrocarbon fraction may include mixtures of normal paraffins, isoparaffins, olefins, naphthenes and aromatics (PIONA). However, one or more chemical groups selected from a list including normal paraffins, isoparaffins, olefins, naphthenes, aromatic hydrocarbons may be absent from the hydrocarbon fraction.

Oxygenate

Suitable oxygenates are aliphatic alcohols or C ₁ -C ₄ ethers. In particular, the oxygenate may be selected from the group consisting of: methanol, ethanol, dimethyl ether, and mixtures thereof, incl. with water. Oxygen may contain impurities, such as aldehydes, carboxylic acids, esters, aromatic alcohols, unsaturated (unsaturated) alcohols.

Olefin-containing fraction

Suitable olefin-containing fractions include from 10.0 to 50.0 wt. % olefins C ₂ -C ₄ (ethylene, propylene, normal butylenes, isobutylene or mixtures thereof). The olefin-containing fraction may contain inert or weakly reactive components other than olefins, for example: methane, ethane, propane, butane, hydrogen, nitrogen. For example, the olefin-containing fraction may contain from 0.5 to 8 wt. % hydrogen, preferably from 2.3 to 8.0 wt. % hydrogen. The olefin-containing fraction may be, for example, thermal or catalytic cracking gases, incl. dry catalytic cracking gas (SGCC), coking off-gas, as well as their mixtures.

OCHI - octane number, determined by the research method. Preferably determined according to ASTM D2699 or GOST 8226.

Products

The proposed catalyst and method for producing a catalyst are particularly effective for the production of gasoline in the processes of joint processing of hydrocarbon fractions, oxygenates and olefin-containing fractions.

As a result of the joint processing of hydrocarbon fractions, oxygenates and olefin-containing fractions, a liquid hydrocarbon product (mainly C ₅₊ hydrocarbons), a gaseous hydrocarbon product (mainly C ₁ -C ₄ hydrocarbons) and an aqueous fraction (formed as a result of the presence of oxygenates in the feedstock) are formed. ). The liquid hydrocarbon product may contain dissolved gases C ₁ -C ₄ , the amount of which is determined based on the needs of a particular enterprise.

In this case, gasoline is characterized as a liquid hydrocarbon product of the process.

Under the gasoline in the present invention refers to motor gasoline or the main component for the production of motor gasoline by compounding and/or fractionation. The name of the liquid hydrocarbon product of the process may vary depending on the environmental requirements of the region or internal production standards. In particular, depending on the environmental requirements for motor gasoline in a particular region, the liquid hydrocarbon product of examples 10-18 may be called motor gasoline or the base (main component) for the production of motor gasoline.

Examples

Characteristics of the catalysts according to the invention and methods for their preparation are described in examples 1-7. Characteristics of the reference catalysts and methods for their preparation are described in examples 8-9. Examples 10-18 describe the results of using the samples of catalysts according to examples 1-9 in the conditions of co-processing of hydrocarbon fractions, oxygenates and olefin-containing fractions.

The catalyst of Comparative Example 8 differs from the catalysts of the invention in that no alkaline treatment of the catalyst composition is carried out during its manufacture. The catalyst according to comparative example 9 differs from the catalysts according to the invention in that boric acid is not used to prepare the catalyst composition.

Table 1 shows the raw materials and production parameters of the catalysts in the examples.

Table 2 shows the characteristics of the catalysts for examples 1-9.

Table 3 shows the characteristics of hydrocarbon fractions.

Table 4 shows the compositions of the olefin containing fractions.

Table 5 shows the conditions and main parameters of examples 10-18.

Oxygenates - as an oxygenate in examples 10-13 and 16-18 used technical methanol brand "A" GOST 2222-95. Example 15 used dimethyl ether (DME), 99%. Example 14 used 95% ethanol.

texture properties. For catalyst samples according to examples 1-9, the textural characteristics of the catalyst were determined on a Micromeritics Gemini VII 2390t instrument, before measurements, the samples were degassed at a temperature of 300°C for 4 hours.

acid properties. For the catalyst samples of Examples 1-9, the acidic properties of the samples were determined by NH ₃ TPD on a Micromeritics AutoChem HP2950 instrument. The test sample was preliminarily calcined at a temperature of 550°C for 4 hours in an air stream, then placed in a quartz reactor and kept in a nitrogen stream at 200°C for 1 hour with a purge rate of 50 ml⋅min ^-1 . Saturation was carried out in a stream of nitrogen-ammonia mixture (10.14 vol. % ammonia) at a temperature of 60°C for 30 min. Removal of physically adsorbed ammonia was carried out at 100°C in a stream of nitrogen for 30 min at a purge rate of 50 ml⋅min ^-1 . Then the sample was cooled down again and the temperature began to rise from 60°C to 750°C at a rate of 10°C⋅min ^-1 and the detector signal was recorded by thermal conductivity.

Examples 1-7 (according to the invention)

The preparation of catalysts according to examples 1-7 was carried out as follows (specific parameter values for each catalyst sample, see Table 1).

Obtaining peptized pseudoboehmite

Peptized pseudoboehmite for examples 1-5 was obtained from thermally activated aluminum hydroxide (TCA product). To do this, thermally activated aluminum hydroxide was ground, ground thermally activated aluminum hydroxide was sent to the reactor for sodium removal. The reactor was filled with 20 l of water and 12 ml of nitric acid with a concentration of 47 wt. %. Then, 2 kg of the milled TCA product was loaded into the reactor. The suspension was heated to 70°C and stirred for 2 hours. After stirring, the suspension was filtered on a vacuum filter, after which the washing operation was repeated until pH=7. The washed and filtered aluminum hydroxide in the form of a moistened powder was sent to be loaded into an autoclave. The washed aluminum hydroxide from the filtration stage was loaded into an autoclave with stirring (TXA:water ratio = 1:2 by weight, acid modulus 0.015). The autoclave was sealed, and the temperature was raised to 150°C with constant stirring. After heating, stirring of the suspension was continued at a constant temperature for 8 hours. Upon completion of the autoclaving process, the resulting pseudoboehmite suspension was transferred from the autoclave to a receiving vessel. Hydration was carried out by adding a solution of nitric acid with a concentration of 47 wt. % to a suspension of pseudoboehmite. The molar ratio of nitric acid/alumina (acid modulus) was 0.15. Hydration was carried out with stirring for 1 hour.

The peptized pseudoboehmite for Examples 6-7 was prepared from pseudoboehmite powder. The powder of pseudoboehmite was peptized under stirring with an aqueous solution of nitric acid with a concentration of 3 wt. % within 30 min. The molar ratio of nitric acid/alumina (acid modulus) was 0.05.

Catalyst production method

Peptized pseudoboehmite was placed into a Z-shaped mixer, HZSM-5 was added, and mixed. The mixture was evaporated with stirring to a pasty consistency.

Then, an aqueous solution of boric acid was added to the mixture of zeolite and pseudoboehmite (calculated amount of boric acid powder (GOST 9656, chemically pure, 99.9 wt %) according to Table 1, dissolution at a temperature of 80°C).

To the resulting mixture was added silica sol with a pH in the range from 8 to 10 (pH values, see Table 1). The resulting mass was evaporated to formability. As a result, a molding mass is obtained.

The resulting molding mass was molded on a granulator with a die size of 3.5–4.0 mm. The granules were dried for 12 h, dried in a convection oven, first at 80°С for 2 h, then at 120°С for 6 h. The granules were calcined in a muffle furnace at 550°С for 6 h , temperature rise 3°C/min. The result is a catalyst composition.

The obtained catalyst composition was subjected to alkali treatment. To do this, the granules of the catalyst composition were placed in a container and a sodium hydroxide solution was added (for the concentration of an aqueous solution of sodium hydroxide, temperature and duration of treatment, see Table 1). Then it was filtered and washed with distilled water to remove alkali residues. The resulting granules were dried in a convection oven, first at 80°C for 2 h, then at 120°C for 6 h. /min

The catalyst composition that underwent alkaline treatment was washed from sodium by the ion exchange method. To do this, the catalyst composition was loaded into the container and an ammonium chloride solution was added (to wash 500 g of the catalyst composition, a solution of 6 g of ammonium chloride per 2.4 l of water was prepared), observing the ratio solid : liquid = 1: 4 by weight. The mixture was left for 1 h without stirring at room temperature, the solution was decanted and, if necessary, repeated ion exchange and washing with water. The final content of Na ₂ O in the catalyst composition did not exceed 0.15 wt %. %. The washed catalyst composition was dried in a convection oven, first at 80°C for 2 h, then at 120°C for 6 h. Then it was calcined in a muffle furnace at 550°C for 6 h, temperature rise 3° C/min

The resulting catalyst composition was impregnated in terms of moisture capacity with solutions of zinc and rare earth elements (compositions of impregnating solutions are given in Table 1). To prepare an impregnating solution, the calculated amount of zinc nitrate was dissolved in water, REE nitrates were added in the form of a powder or in the form of an industrial concentrate of REE nitrates (for catalysts including praseodymium and neodymium) and brought to the required volume with distilled water. Impregnation was carried out once according to moisture capacity. The mixture of catalyst composition and impregnating solution was vigorously stirred for 1 hour.

Upon completion of the impregnation, the granules were dried for 30 min. The resulting impregnated granules were dried in a convection oven, first at 80°C for 2 hours, then at 120°C for 6 hours. The dried product was calcined in a muffle furnace at 550°C for 6 hours. °C/min.

The result is a catalyst.

Example 8 (comparative)

The catalyst according to example 8 was obtained analogously to examples 1-7, however, alkali treatment of the catalyst composition was not carried out.

Peptized pseudoboehmite for example 8 was obtained analogously to examples 1-5

Examples 9 (comparative)

The catalyst according to example 9 was obtained similarly to examples 1-7, however, an aqueous solution of boric acid was not added to the mixture of zeolite and pseudoboehmite.

Peptized pseudo-boehmite for example 9 was obtained analogously to examples 1-5.

Examples 10-18

Examples 10-18 show cases of obtaining gasolines. Depending on the environmental requirements of a particular country and the internal requirements of the enterprise, the resulting product can be considered as gasoline ready for commercial sale, or as the main component for the preparation of commercial gasoline by compounding and / or fractionation.

For examples 10-18, a catalytic plant was used, including a catalytic reactor, automatic gas flow regulators, gas pressure reducers, a pressure regulator "to itself", a gas meter, pumps for supplying liquid raw materials, a cooled separator trap in which liquid products are collected catalysis, a cryothermostat-circulator, and an automatic temperature controller. The reactor is equipped with two channels for thermocouples, axial and near-wall. The internal diameters of the channels are 3 mm. The axial channel is used to measure the temperature along the catalyst bed, the wall channel is used to install a temperature controller thermocouple. The temperature in the reactor is controlled by a temperature controller at the point where the thermocouple is installed in the near-wall channel. The thermocouple in the near-wall channel is installed at the level of the lower boundary of the catalyst layer.

A preliminarily weighed catalyst (catalyst particle size 1–1.5 mm) was placed in a reactor between quartz layers, purged with an inert gas, after which this reactor was checked for leaks. For this, nitrogen was supplied to the stand through the reactor. The duration of the purge was 10-15 minutes. With the help of a pressure regulator “up to oneself”, the working pressure was set and the reactor and the communications leading to it were checked for tightness. According to the results of the reactor tightness check, its heating was switched on. When the operating parameters of temperature and pressure were reached, liquid hydrocarbon feedstock (hydrocarbon fractions and oxygenates) was supplied to the reactor using dosing pumps. The supply of gaseous olefin-containing fractions was carried out using gas flow regulators. Liquid and gaseous products formed in the course of chemical reactions leave the reactor, are cooled in a refrigerator, pass through a pressure regulator and are collected in a cooled trap. The trap coil constantly circulates refrigerant. Circulation is carried out by a cryothermostat-circulator. Gaseous products from the trap are discharged through the gas meter to the candle. After the end of the experiment, the supply of feedstock was stopped, the pressure in the reactor was dropped to atmospheric pressure, and nitrogen was supplied to the reactor for 15-20 minutes.

The activity and selectivity of zeolite-based catalysts tend to decrease during operation due to various deactivation mechanisms. To maintain comparable activity and/or selectivity, the reaction temperature is gradually increased. The regeneration period in examples 10-18 was defined as the time period starting from the moment the raw materials were supplied to the reactor and ending when the temperature in the catalyst bed reached more than 550°C. During the reaction, the oxygenate in the aqueous phase of the product was monitored at least 3 times a day. In the case of the appearance of oxygenate in the reaction products in an amount corresponding to an oxygenate conversion of less than 98%, the temperature of the catalyst layer was increased. If the temperature in the catalyst bed exceeded 550°C, the experiment was stopped.

Claims (26)

1. Catalyst for the production of gasoline in the joint processing of hydrocarbon fractions, oxygenates and olefin-containing fractions, including zeolite ZSM-5 in an amount of from 50.0 to 85.0 wt. %, where: a. the pore volume of the catalyst is from 0.15 to 0.26 cm ³ /g, b. the average pore diameter of the catalyst is from 38 to 53 Å, c. the ratio of weak and strong acid sites of the catalyst is from 2.2 to 3.5, moreover, the catalyst includes by chemical composition in terms of oxides: d. silicon dioxide in an amount from 53.0 to 85.0 wt. %, e. aluminum oxide in an amount from 10.9 to 43.0 wt. %, f. boron oxide in an amount of 0.5 to 2.5 wt. %, g. zinc oxide in an amount of 1.4 up to 2.9 wt. %, h. oxides of rare earth elements in an amount of 0.9 to 2.0 wt. %. 2. The catalyst according to claim 1, in which the catalyst is used for the co-processing of hydrocarbon fractions, oxygenates and olefin-containing fractions into gasolines, preferably the catalyst is used for a gasoline production process in which three streams are used as feedstock, one of which includes a hydrocarbon fraction , the second stream includes an oxygenate, the third stream includes an olefin-containing fraction, where the olefin-containing fraction includes one or more olefins selected from the group including: ethylene, propylene, normal butylenes, isobutylene, in a total amount of from 10.0 to 50.0 wt. %. 3. The catalyst of claim. 1, in which the rare earth elements include one or more elements selected from the group including: lanthanum, praseodymium, neodymium, cerium. 4. The catalyst according to claim 1, in which the catalyst does not contain one or more elements selected from the group including: platinum metals, iron, cobalt, nickel. 5. The catalyst according to claim 1, wherein the zeolite has a silica module SiO ₂ /Al ₂ O ₃ in the range of 50 to 90, preferably 60 to 80. 6. The method of obtaining a catalyst according to any one of paragraphs. 1-5, including the following steps: a. adding HZSM-5 to peptized pseudoboehmite to obtain a mixture of zeolite and pseudoboehmite, b. adding boric acid to a mixture of zeolite and pseudoboehmite, c. adding silica sol with a pH of 8-10 to the mixture obtained in step (b) to obtain a molding composition, d. molding, drying and calcining the molding mass to obtain a catalyst composition, e. alkaline treatment of the catalyst composition obtained in step (d), f. washing the catalyst composition obtained in step (e) from sodium, drying and calcining, g. impregnation of the catalyst composition obtained in step (f) with solutions of zinc and rare earth salts, drying and calcination. 7. The method of claim 6, wherein the alkaline treatment uses an aqueous alkali solution with a pH of 10 to 14, preferably a pH of 12 to 14. 8. The method according to p. 6, in which an aqueous solution of sodium hydroxide with a concentration of 0.01-0.5 M is used for alkaline treatment. 9. The method according to p. 6, in which the alkaline treatment is carried out by heating to 30-80°C. 10. The method of claim. 6, in which impregnation of the catalyst composition using impregnation by moisture capacity or impregnation in excess solution.