RU2751336C1 - Catalyst, method for its preparation, and method for transalkylation of benzene with diethylbenzenes using it - Google Patents

Abstract

FIELD: chemistry.SUBSTANCE: invention relates to methods for producing a transalkylation catalyst, including zeolite and an inorganic binder, to a catalyst and a method for transalkylating aromatic hydrocarbons to form ethylbenzene in the presence of the resulting catalyst. A catalyst containing more than 65% of the volume of meso-and macropores with a diameter of 2-50 nm is prepared by mixing, weight percentage of the resulting catalyst: 80-90 zeolite Y in H+REE form with a particle size of no more than 2 microns, 10-20 binder, 1-3 plasticizer, pellet forming, drying and calcining. Next, the granules are activated with an acid solution with a concentration of 0.1-0.3 n at 70-90°C, for 1.0-1.5 hours, the granules are washed, dried and calcined.EFFECT: invention provides increased conversion of diethylbenzenes, the yield of ethylbenzene, and increased strength of the catalyst.6 cl, 1 tbl, 10 ex

Description

The invention relates to methods for producing a transalkylation catalyst comprising a zeolite and an inorganic binder, to a catalyst, and to a method for transalkylating aromatic hydrocarbons with the formation of ethylbenzene in the presence of the resulting catalyst. The invention can be used in the petrochemical industry.

Known "Alkylation catalyst and method for its preparation" (US Pat. US 5036033 from 30.07.1991). The catalyst is used in the processes of alkylation and transalkylation of aromatic hydrocarbons with olefins C ₂ -C ₄ and contains an ultrastable zeolite Y in an acidic H ⁺ -form with a SiO ₂ / Al ₂ O ₃ molar ratio less than or equal to 20. The catalyst contains from 70 to 95 wt. % zeolite and 5-30 wt.% binder - aluminum oxide. Sodium oxide content less than 0.6 wt%

A known method of producing ethylbenzene (US Pat. US 4169111 from 25.09.1979). As an active component of the catalyst, parastabilized zeolite Y is used in the acidic H ⁺ form with a molar ratio of SiO ₂ / Al ₂ O ₃ from 4 to 12. The catalyst contains 90 wt.% Zeolite and 10 wt.% Binder - alumina (however, more often total binder content 30 wt.%, and zeolite 70 wt.%). The preferred diameter of meso- and macropores in the catalyst granules is from 30 to 100 nm. Sodium oxide content less than 0.5 wt%

The known method of alkylation and transalkylation using zeolite catalysts (US Pat. US 5324877 from 28.06.1994). The patent describes a method for preparing a catalyst that contains 90 wt.% Of ultrastable zeolite Y in acidic H ⁺ -form and 10 wt.% Of a binder — alumina. The molar ratio SiO ₂ / Al ₂ O ₃ in the zeolite is from 6 to 12. The content of Na ₂ O in the catalyst is less than or equal to 0.6 wt.%

Known "Processes of liquid-phase alkylation and transalkylation" (US Pat. US 4459426 from 12.07.1982) of aromatic hydrocarbons with olefins C ₂ -C ₄ . The catalyst for these processes contains zeolite Y in an acidic H ⁺ -form and a binder - alumina at a weight ratio of 75/25 to 90/10. The preferred diameter of the meso- and macropores in the catalyst granules is from 30 to 100 nm. The content of Na ₂ O in the catalyst is less than or equal to 0.7 wt.%, In addition, the catalysts contain 0.5-5.0 wt.% Of Group II metal oxides.

As catalysts for liquid-phase alkylation or transalkylation of aromatic hydrocarbons, other catalysts are also used, the active components of which are zeolites of the beta or mordenite types.

The known method of liquid-phase alkylation or transalkylation on a catalyst containing a zeolite of the beta type (US Pat. US 5081323 from 14.01.1992). The catalyst contains 60-80 wt.% Zeolite with a molar ratio of SiO ₂ / Al ₂ O ₃ from 5 to 50 in the acidic H ⁺ -form and the binder is aluminum oxide.

Known "Catalyst composition for the alkylation of aromatic compounds, a method for their alkylation and transalkylation" (US Pat. RU 2147929 from 15.06.1995), "Catalyst composition and a method of alkylation and / or transalkylation of aromatic compounds" (US Pat. RU 2189859 from 11.12.1997). The catalysts contain 50-90 wt.% Zeolite beta in the acidic H ⁺ -form, and the rest is a binder (aluminum oxide). In this case, the extrazeolite (meso- and macro-) porosity of the granules - the pore volume with a radius of more than 10 nm is at least 35% of the total pore volume. The processes for the alkylation and transalkylation of aromatic compounds use the same catalyst. In US Pat. RU 2189859 shows a typical block diagram of the preparation of a transalkylation catalyst consisting of a zeolite and a binder.

Known "Catalyst for the processes of alkylation and transalkylation of aromatic hydrocarbons" (US Pat. US 4849570 from 11/03/1988). The catalyst contains from 75 to 90 wt.%) Mordenite zeolite in acidic H ⁺ -form and a binder (aluminum oxide) - the rest. The catalyst is produced in the form of spherical, extruded or granular granules. The examples describe a method for preparing a catalyst.

A known method for producing a catalyst for transalkylation and a method for transalkylating benzene with diethylbenzenes with its use (US Pat. RU 2478429 from 28.07.2011). A catalyst for the transalkylation of benzene with diethylbenzenes is obtained in the form of cylindrical granules of regular shape, containing 100 wt.% Of zeolite Y in acid H ⁺ -form, which with a degree of substitution of Na ⁺ ions by H ⁺ not less than 0.95 and more than 80% of the volume of transport pores the granules are pores with a diameter greater than 100 nm. The method for preparing the catalyst includes sequential treatment with aqueous solutions of ammonium salts with a concentration of 20-25 g / dm ³ (in terms of NH ₄ ⁺ ) at a ratio of the mass of granules: solution volume equal to (1: 6) - (1: 7) and temperatures of 80 -90 ° C for 1.0-1.5 hours, alternating three or four stages of said treatment with two or three intermediate calcinations, respectively, at temperatures of 540-600 ° C for 3-4 hours. Using the above catalyst, transalkylation is carried out benzene with diethylbenzenes at elevated temperature and pressure.

The closest in technical essence and the achieved result to the proposed invention is "Catalytic composition and method of transalkylation of aromatic hydrocarbons" (US Pat. RU 2351393 from 15.12.2003, class B01J 29/04; B01J 35/10; B01J 37/04; С07С 6 / 12; C10G 29/20), which was chosen as the prototype.

According to the prototype, the catalytic composition contains dealuminated zeolite Y in acidic H + -form with a molar ratio of SiO ₂ / Al ₂ O ₃ from 10 to 20 and a binder γ - aluminum oxide. The mass ratio of zeolite / binder is in the range from 1: 1 to 4: 1.

The catalytic composition is cylindrical granules of regular shape with a diameter of at least 1.8 mm. Granules have a well-developed structure of transport pores and at least 30% of the volume of meso- and macropores falls on pores with a diameter greater than 100 nm.

The strength of these granules is 1.7 kg / mm (crushing strength / granule length) or 0.8 kg / mm ² (crushing strength / granule cross-sectional area).

The method for preparing the catalytic composition in accordance with the prototype includes the following stages:

- preparation of a mixture consisting of zeolite Y in acidic H ⁺ -form and a binder precursor selected from boehmite or pseudoboehmite by mechanical mixing of the components in a high-speed mixer;

- slowly adding to this mixture (with constant stirring) a solution of acetic acid with a concentration of not more than 0.5 wt.% in such an amount that the final ratio of the mass of acid to the total mass of the mixture is from 0.25 to 0.50%;

- extrusion molding of the mixture;

- drying the obtained granules in a stream of air at a temperature not exceeding 30 ° C for at least 48 hours;

- a stepwise rise in temperature (22 h) to the final calcination temperature (550-600 ° C) and holding at this temperature for 8 h.

The method of transalkylation of aromatic hydrocarbons involves the interaction of benzene with diethylbenzenes in the presence of a catalyst composition containing not more than 80 wt.% Of zeolite Y in acidic H ⁺ -form with a molar ratio of SiO ₂ / Al ₂ O ₃ in the range from 11 to 17. The reaction is carried out in liquid or in the gas-liquid phase at a temperature of 150-300 ° C; pressure 20-50 atm; volumetric feed rate of the raw material 0.5-10 h ^-1 , molar ratio benzene: diethylbenzene, equal to (3-30): 1.

The known catalytic composition (prototype), a method for its production and a method for transalkylation of aromatic hydrocarbons with its use has the following disadvantages:

- a low content of zeolite Y in the acidic H + -form (no more than 80 wt.%) in the composition of the catalyst, which leads to insufficiently high activity of the catalyst in the reaction of transalkylation of benzene with diethylbenzenes, namely, low conversion rates of diethylbenzenes and the yield of the target product, ethylbenzene;

- the catalytic composition has an insufficiently developed secondary porous structure of granules, which complicates the delivery of reactants to the active centers of the catalyst and the removal of reaction products and, ultimately, reduces the activity of the compositions due to their premature deactivation;

- low mechanical strength of the catalytic composition, which leads to the formation of dust and crumbs at the stages of production, transportation, as well as during operation and regeneration of the catalyst.

The technical problem to be solved by the claimed invention is to simplify the method for producing a catalyst with high activity in the reactions of transalkylation of benzene with diethylbenzenes and high strength of the granules.

The purpose of the present invention is to improve the method of liquid-phase transalkylation of benzene with diethylbenzenes, namely, to increase the conversion of diethylbenzenes, the yield of ethylbenzene, to increase the strength of the catalyst and to eliminate the formation of crumbs and dust during the production, transportation, operation and regeneration of the catalyst.

This goal is achieved through the use in the method of transalkylation of a catalyst in the form of mechanically strong granules containing more than 65% of the volume of meso- and macropores with a diameter of 2-50 nm. The catalyst is obtained by mixing 80-90 wt% of zeolite Y powder in H ⁺ REE - form with a particle size of not more than 2 μm, 10-20 wt% of a binder, a plasticizer in an amount of 1-3 wt% for the resulting catalyst, extrusion molding granules, drying and calcining. Next, the granules are activated with an acid solution with a concentration of 0.1-0.3 n at a temperature of 70-90 ° C, for 1.0-1.5 hours, the granules are washed with demineralized water, dried and calcined.

It is most optimal to obtain a catalyst under the following conditions:

- drying the granules at a temperature of 120-150 ° C for 3-4 hours, calcining the granules at a temperature of 540-600 ° C for 6 hours;

- activation with an acid solution at the ratio of the mass of the granules (g): the volume of the solution (ml), equal to from 1: 6 to 1: 7;

- the use of powder of zeolite Y with a molar ratio of SiO ₂ / Al ₂ O ₃ from 5 to 11 and a REE content of 5-6 wt.%.

As a plasticizer, starch, carboxymethyl cellulose (CMC), methyl cellulose, polyesters (for example, polyethylene glycol) can be used.

As an acid, organic (for example, citric) and inorganic (for example, hydrochloric) acids can be used.

The resulting catalyst is used for the transalkylation of benzene with diethylbenzenes in the liquid phase at elevated temperatures and pressures.

The essence of the invention is illustrated by examples 2-5. Examples 6-10 are comparative.

Example 1 (prototype).

80 g (in terms of absolutely dry matter) zeolite Y CBV 712 (molar ratio SiO ₂ / Al ₂ O ₃ , REE content 5.5 wt.%) In powder form and 20 g (in terms of absolutely dry matter) pseudoboehmite Versal V-250 in powder form is loaded into a turbomixer (the number of revolutions of the mixer is 1000 rpm). Then add 58 cm ³ aqueous solution of glacial acetic acid 0.5 wt.% At a constant rate for 36 minutes at a speed of rotation of the mixer 400 rpm. The mixture is then further stirred at a stirrer speed of 400 rpm for 12 minutes. The resulting mass is subjected to extrusion. The extruded product in the form of regular cylinders with a diameter of 2.1 mm is placed in a drying oven and dried at a temperature of 25 ° C for 48 hours. Then the granules are calcined in a stepwise temperature regime. The temperature is raised from room temperature to 120 ° C within 360 min, held at this temperature for 120 min, from 120 to 350 ° C - for 360 min, held at this temperature for 240 min, from 350 to 550 ° C - for 240 min, kept at this temperature for 480 min. The finished catalyst is analyzed.

The determination of the mechanical crushing strength is carried out according to OST 38.01134-77. Catalysts and adsorbents. - 1978.

The porous structure of the granules is investigated by the method of mercury porosimetry on a mercury porosimeter "Porosimeter-2000" by measuring the curves of indentation of mercury. The penetration of mercury into pores with a diameter of 8 to 2000 nm is carried out at a pressure of 0.1 to 200 MPa. The properties of the catalyst are shown in Table 1.

Example 2.

Stir in a turbomixer at a stirrer rotation speed of 400 rpm, the following wetted components:

- 80 g (in terms of absolutely dry matter) zeolite Y in H ⁺ REE - form (molar ratio SiO ₂ / Al ₂ O ₃ = 7) in powder form with a particle size of 1 micron;

- 20 g (in terms of absolutely dry matter) pseudoboehmite Versal V-250 in powder form;

- 2 g (in terms of absolutely dry matter) starch (plasticizer).

The resulting mass is subjected to extrusion. The extruded product in the form of regular cylinders 2.1 mm in diameter is dried at a temperature of 120-150 ° C for 3-4 hours. Then the granules are calcined at a temperature of 540-600 ° C for 6 hours. concentration of 0.2 N at a temperature of 80 ° C, for 1.0 h and the ratio of the mass of granules (g): solution volume (ml), equal to (1: 6). Washing is carried out with demineralized water, drying at a temperature of 120-150 ° C for 4 hours and calcination at a temperature of 540-600 ° C for 6 hours.

The properties of the catalyst are shown in Table 1.

Example 3-5. The experiments were carried out in accordance with example 2.

Comparative examples 6-10 were performed similarly to example 2, with the following differences.

In example 6, the content of the plasticizer is higher than required.

In examples 7, 10, the content of the ratio of zeolite / binder is different from the required.

In example 8, the activation conditions with an acid solution differ from the required one.

In example 9, the fineness of the zeolite powder differs from the required one.

The catalytic properties of the known and synthesized catalysts (examples 1-10) are evaluated in isothermal mode in a flow-through unit. The reactor is charged with 30 cm ^{3 of the} catalyst, which is pre-crushed to obtain a uniform (along the length of the granules) fraction of 2.5-3 mm. The space under and above the catalyst bed is filled with broken quartz (packing) of 2.5-3 mm fraction. The height of the loaded catalyst bed and packing is 75-80 mm, the inner diameter of the reactor is 25 mm.

Before starting the tests, the system is sealed. The furnace is heated and the temperature in the reactor is raised to 150-160 ° C at a rate of no more than 20 deg / h. At this temperature, the catalyst is dried in a stream of nitrogen for 3-4 hours, then the temperature is raised to 220 ° C and the catalyst is additionally kept at this temperature for 1 hour. The reaction temperature is maintained automatically. The pressure in the reactor is set to 2.5 MPa and the feed is started.

A mixture of benzene according to GOST 9572-93 and diethylbenzenes according to TU 2414-135-05766575-2007 is used as raw material.

Test conditions for the obtained catalysts:

temperature, ° С 210 pressure, MPa 2.5 space velocity for raw materials, h ^-1 1.0 mass ratio benzene / diethylbenzenes 5/1 experiment duration, h 56

The composition of the raw material and the reaction products are analyzed by chromatography on a Kristallux-4000M device on a 60 m long capillary column treated with ZB WAX in a programmed temperature rise mode using a flame ionization detector. Components are identified by comparing their retention times with reference individual substances. Calculation of chromatograms is carried out by the "internal normalization" method.

The conversion of diethylbenzenes (DEB) is calculated by the formula, (X),%:

where C ₁ is the mass fraction of DEB in the raw material, wt%;

С ₂ - mass fraction of DEB in catalysis, wt%.

The ethylbenzene yield (wt%) is taken from these chromatograms. The catalytic properties of the catalysts obtained in examples 1-10 are shown in table 1.

As the comparative examples show, deviations from the claimed invention do not allow solving the technical problem.

Thus, the claimed technical result is achieved only in the totality of the features given in the claims.

Claims (6)

1. A method of obtaining a catalyst for the transalkylation of benzene with diethylbenzenes, including the preparation of cylindrical granules by mixing zeolite and a binder, extrusion molding of granules, drying and calcining the granules, characterized in that 10-20 wt.% Binder, 80-90 wt.% Zeolite powder are mixed Y in H ⁺ REE-form with a particle size of no more than 2 microns, plasticizer in an amount of 1-3 wt.% For the resulting catalyst, the formed granules are dried and calcined, the granules are activated with an acid solution with a concentration of 0.1-0.3 N at a temperature 70-90 ° C, for 1.0-1.5 hours, the granules are washed with demineralized water, dried and calcined. 2. The method according to claim 1, characterized in that the drying of the granules is carried out at a temperature of 120-150 ° C for 3-4 hours, the calcination of the granules is carried out at a temperature of 540-600 ° C for 6 hours. 3. A method according to claim 1, characterized in that upon activation with an acid solution, the ratio of the mass of the granules (g): the volume of the solution (ml) is from 1: 6 to 1: 7. 4. The method according to claim 1, characterized in that the powder of zeolite Y is used with a molar ratio of SiO ₂ / Al ₂ O ₃ from 5 to 11 and a REE content of 5-6 wt.%. 5. Catalyst for transalkylation of benzene with diethylbenzenes in the form of granules, characterized in that the catalyst is obtained according to PP. 1-4 and contains more than 65% of the volume of meso- and macropores with a diameter of 2-50 nm. 6. A method for the transalkylation of benzene with diethylbenzenes, comprising the interaction of benzene with diethylbenzenes in the liquid phase on a zeolite-containing catalyst at elevated temperature and pressure, characterized in that the catalyst according to claim 5 is used.