RU195954U1 - AUTOCLAV FOR PROCESSING ZEOLITE BY ION EXCHANGE - Google Patents

Abstract

The utility model relates to the field of preparation of zeolite catalysts and can be used in catalysis, in particular in the catalysis of isobutane alkylation by butylene. The autoclave for treating zeolite by ion exchange, made in the form of a cylindrical body, equipped with a sealed cap and a heating element, is made so that the body fixed in a stationary rack with the ability to adjust the angle of inclination of the case within 30-60 °. At the base of the strut, made in the form of a truncated trapezoid, there is an engine connected on one side to the rotational speed setter of the case, and on the other hand, with a rotational mechanism that ensures rotation of the case. Technical result: efficient mixing of zeolite granules without violating their integrity at different degrees of loading zeolite. 1 fig., 7 ave.

Description

The utility model relates to the field of preparation of zeolite catalysts and can be used in catalysis, in particular in catalysis of isobutane alkylation by butylene.

A known autoclave for treating zeolite by ion exchange, comprising a housing equipped with a stirrer, a device for rotating the stirrer, a device for heating the autoclave body, in which ion exchange of type Y zeolite with silicate module 5.2 in a solution of ammonium salt and heat treatment of the ammonium form is carried out. The obtained zeolite catalyst is used for cracking and hydrocracking (see, RF patent No. 2374178 C1, CL IPC 39/24, publ. 11/27/2009).

A disadvantage of the known autoclave is that mixing is possible using a mixer installed in it, and is suitable only for powder zeolites, while mixing granular or molded zeolites using the described autoclave leads to the destruction of zeolite granules.

Known autoclave for processing zeolite by ion exchange, including a housing, a furnace in which it is placed, a device for rotating the housing of the autoclave in the furnace. Treated zeolites are used as carbonylation catalysts of dimethyl ether or methanol with carbon monoxide in the presence of mordenite catalyst (see RF patent 2525916 C2, class IPC C07C 51/12, C07C 67/37, C07C 53/08, C07C 69/14, B01J 29/20, B01J 29/24, B01J 37/00, B01J 37/04, published on 08.20.2014).

A known autoclave for processing zeolite by ion exchange, including a housing, a device for rotating it, a device for heating it. The obtained zeolite catalyst is used for the alkylation of benzene with olefins (AS USSR 1370859 A1, class IPC B01J 37/02, B01J 29/08, publ. 20.10.1996).

A known autoclave for preparing a catalyst based on zeolite by ion exchange, including a housing, a device that ensures its rotation, a device that provides its heating, in which the ion exchange is carried out during its rotation at a temperature of 150-200C, a pressure of 8-40 atm for 1- 6 hours. The obtained zeolite catalyst is used for the alkylation of isobutane or benzene with C2-C4 olefins (USSR AS No. 936991, class IPC B01J 37/30, B01J 29/08, publ. 06.23.1982).

In all described known autoclaves, mixing is ensured by rotation of the housing, which eliminates the destruction of the granules.

A common disadvantage of the described devices is the fact that effectively mixing is carried out only in the upper part of the device, and the suspension in its lower part remains practically unmixed. In addition, the mixing efficiency depends on the degree of loading of the autoclave - the more loaded the autoclave, the less efficient is the mixing of the loaded zeolite suspension.

Closest to the proposed device is a stationary autoclave for producing an isobutane alkylation catalyst with zeolite-based olefins (see RF patent No. 2445164 C1, class IPC B01J 29/12, B01J 29/14, B01J 29/16, B01J 23/02, B01J 23/10, B01J 37/02, C07B 37/00, published March 20, 2012), including its treatment with aqueous solutions of calcium salts, rare earth element and ammonium at elevated temperature and pressure of saturated vapors, followed by the application of active metals by impregnation with aqueous solutions of salts active metals, then washing, drying, tableting, as used powdered faujasite type zeolite, and calcining. Treatment with aqueous solutions is carried out in a stationary autoclave without stirring while heating the autoclave 160-220 ° C.

A disadvantage of the known autoclave is the fact that it is stationary and works without mixing solutions of salts and zeolite, which leads to incomplete ion exchange due to the lack of effective mixing.

The objective of the utility model is the development of an autoclave that provides effective mixing of zeolite granules without violating their integrity with varying degrees of zeolite loading.

To solve this problem, an autoclave has been developed for processing zeolite by ion exchange, made in the form of a cylindrical body, equipped with a sealed cover and a heating element, in which the body is mounted in a stationary rack with the ability to adjust its angle of inclination within 30-60 degrees, at the base of the rack, made in the form of a truncated trapezoid, an engine is located, connected on one side to the rotational speed setter of the case, and on the other hand, with a rotational mechanism that ensures rotation of the case.

The technical result from the use of the proposed utility model is to effectively mix the zeolite granules without violating their integrity at different degrees of zeolite loading.

The autoclave is shown in FIG. 1 and consists of

1 - cylindrical body;

2 - a tight cover;

3 - heating element;

4 - stationary rack;

5 - engine;

6 - setpoint speed of the housing;

7 - rotational mechanism.

The proposed device operates as follows.

In a cylindrical body (1) with a sealed cover (2), zeolite is poured, which is poured with a prepared salt solution. The cylindrical body (1), equipped with a heating element (3), is mounted on a stationary stand (4), which allows you to adjust the angle of inclination of the autoclave. The angle of inclination of the autoclave is selected in the range from 30 to 60 degrees, depending on the amount of zeolite loaded for exchange. A motor (5) is installed on a stationary stand (4), which ensures the rotation of the autoclave with a predetermined number of revolutions on the rotational speed setter of the housing (6), through a rotational mechanism (7).

At the end of ion exchange, the cylindrical body (1) is cooled, after which the rotation of the body is stopped, the sealed cover (2) is removed and the mother liquor with the treated zeolite is removed. The zeolite is washed with demineralized water, dried and calcined after the last ion exchange.

The installation of the autoclave at an angle ensures efficient mixing of the granules without disturbing them, and the angle of inclination can be changed depending on the varying degree of loading of the zeolite.

The technical result that can be obtained is the effective mixing of zeolite granules without violating their integrity with varying degrees of zeolite loading.

The implementation of the invention is confirmed by the following examples.

Example 1

The zeolite-based catalyst is prepared in the proposed autoclave, located obliquely with a total charge of the initial zeolite and salt solution, not exceeding 90% of the volume of the cylindrical body of the autoclave.

The angle of inclination of the housing is set equal to 60 degrees.

As a zeolite, granular NaX type zeolite with a granule size of 2-4 mm is used. A sample of zeolite on a completely dry substance (in terms of a substance calcined at 400 ° C) is 30 g. A series of ion exchanges is carried out with a suspended sample.

The first ion exchange.

9.0 g of Ca (NO ₃ ) ₂ * 4H ₂ O salt are dissolved in 240 g of distilled water. Into the resulting solution, NaX zeolite is introduced, granulated without a binder, with a Na ₂ O content of up to 16.5% by mass, in an amount corresponding to the zeolite: solution mass ratio = 1: 8. The saline solution with zeolite is placed in an insert cup, which is installed in an autoclave and exchanged at a temperature of 155 ° C, with an autoclave inclination angle of 45 °, a rotation speed of 1 revolution per minute for 6 hours. The treated granules are filtered off, washed and dried.

The second ion exchange.

34.1 g of La (NO ₃ ) ₃ * 6H ₂ O salt are dissolved in 240 g of distilled water. The calcium nitrate treated CaNaX zeolite is added to the resulting solution in an amount corresponding to the weight ratio of zeolite: solution = 1: 8. The saline solution with zeolite is placed in an insert cup, which is installed in an autoclave and exchanged at a temperature of 155 ° C, with an autoclave inclination angle of 45 degrees, a rotation speed of 1 revolution per minute for 6 hours. The treated granules are filtered off, washed and dried.

Third ion exchange.

34.1 g of La (NO ₃ ) ₃ * 6H ₂ O salt and 6.3 g of NH ₄ NO ₃ salt are dissolved in 240 g of distilled water. Zeolite treated with calcium nitrate and lanthanum nitrate is introduced into the resulting solution in an amount corresponding to the mass ratio of zeolite: solution = 1: 8. A saline solution with zeolite is placed in an autoclave body and exchanged at a temperature of 155 ° C, with an autoclave inclination angle of 45 °, a rotation speed of 1 revolution per minute for 6 hours. The treated granules are filtered off, washed and dried.

The completeness of ion exchange is evaluated by elemental analysis of the treated zeolite, for example, by x-ray fluorescence analysis.

After triple ion exchange, the content of Na ₂ O is 0.7% by mass, CaO is 0.7% by mass, La ₂ O ₃ is 20.1% by mass.

No destruction of the granules is observed - the size of the granules discharged after the ion exchange of the zeolite is 2-4 mm, as in the original.

Example 2

A zeolite-based catalyst is prepared in the proposed autoclave, as described in Example 1, with a total charge of the initial zeolite and salt solution not exceeding 75% of the volume of the cylindrical body of the autoclave.

The angle of inclination of the housing is set equal to 45 degrees.

As a zeolite, granular NaX type zeolite is used (granule size 2-4 mm).

After triple ion exchange, the content of Na ₂ O is 0.7% by mass, CaO is 0.7% by mass, La ₂ O ₃ is 20.1% by mass.

Granule destruction is not observed: the granule size is 2-4 mm.

Example 3

A zeolite-based catalyst is prepared in the proposed autoclave, as described in Example 1, with a total charge of the initial zeolite and salt solution not exceeding 50% of the volume of the cylindrical body of the autoclave.

The angle of inclination of the housing is set equal to 30 degrees.

As a zeolite, granular NaX type zeolite is used (granule size 2-4 mm).

After triple ion exchange, the content of Na ₂ O is 0.7% by mass, CaO is 0.7% by mass, La ₂ O ₃ is 20.1% by mass.

No destruction of the granules is observed: the size of the zeolite granules after ion exchange, like the initial zeolite, is 2-4 mm.

According to the obtained data of examples 1-3, it can be noted that the degree of loading of the autoclave does not reduce the efficiency of ion exchange. This result is achieved by adjusting the angle of inclination of the autoclave body.

Example 4 (comparative)

The ion exchange is carried out under the same conditions as in example 1, but when using a stationary autoclave without rotation of the body.

A catalyst prepared by sequential ion exchange of granular NaX type zeolite in solutions of calcium nitrate, lanthanum and ammonium salts with a mass ratio of solution to zeolite of 8 to 1 in a stationary autoclave at a temperature of 155C without stirring.

The zeolite granules are not destroyed, and the granule size is 2-4 mm.

However, the ion exchange was carried out nonuniformly along the height of the loaded zeolite layer, which is due to the lack of mixing of the zeolite and salt solution.

Example 5 (comparative)

Ion exchange is carried out under the same conditions as in example 1, but using a stationary autoclave with a stirrer.

When conducting ion exchange on a granular zeolite-based catalyst in an autoclave equipped with a heating element and a stirrer that mixes the initial zeolite and a solution of salts of calcium, lanthanum and ammonium nitrates at a mass ratio of solution to zeolite of 8 to 1 in a stationary autoclave at a temperature of 155C, it is observed crushing of the granules of the catalyst, even when exchanging for 30 minutes, the granule size was 0.5-2 mm

During full ion exchange, the main part of the catalyst becomes dust, and for its further use in the alkylation process with a stationary catalyst layer, an additional pressing or molding process is necessary.

Example 6 (comparative by AS USSR 936991).

The sequential ion exchange of granular zeolite is carried out in an autoclave with rotation of the autoclave body without tilt in two stages: the first is the ion exchange of zeolite in an aqueous solution of calcium chloride at a concentration of 40 g / l at a temperature of 150 ° C for 6 hours, the second is the ion exchange of zeolite in water a solution of a mixture of rare earth nitrates (REE) and ammonium concentration of 15 g / l at a temperature of 180 ° C for 3 hours. At the end of ion exchange, the treated zeolite is washed, dried and calcined.

Zeolite granules are not destroyed.

The resulting zeolite contains Na ₂ O 0.6% wt., CaO - 2.7% wt., REE ₂ O ₃ - 12.8% of the mass.

Example 7 (comparative by AS USSR 936991).

The sequential ion exchange of granulated Faujasite-type zeolite is carried out in an autoclave with the autoclave body rotating without tilting in two stages: the first is the ion exchange of zeolite in an aqueous solution of calcium chloride at a concentration of 40 g / l at a temperature of 160 ° C for 4 hours, the second is the ion exchange of zeolite in an aqueous solution of a mixture of rare earth nitrates (REE) and ammonium at a concentration of 80 g / l at a temperature of 220 ° C for 1 h. At the end of ion exchange, the treated zeolite is washed, dried and calcined.

The obtained zeolite contains Na ₂ O 0.4% wt., CaO - 2.5% wt., REE ₂ O ₃ - 14.1% of the mass.

Zeolite granules are not destroyed.

However, an analysis of the data obtained in comparative examples 6 and 7 (a.s. of the USSR 936991) shows that the amount of rare earth oxides in the resulting catalysts for these examples does not exceed 15.0 wt.% (12.8 and 14.1% mass., respectively), which is associated with insufficiently effective mixing in examples 6 and 7 and, as a result, with incomplete ion exchange. While according to the proposed method receive a catalyst containing 20.1% of the mass. lanthanum oxide, which is associated with more efficient mixing and, as a result, with more efficient ion exchange.

Thus, the proposed autoclave allows you to organize effective mixing of zeolite granules and salt solution without violating the integrity of the granules. It is shown that the autoclave allows ion exchange with different charges, while the mixing efficiency remains unchanged.

Claims (1)

An autoclave for processing zeolite by ion exchange, made in the form of a cylindrical body, equipped with a sealed cover and a heating element, characterized in that the body is fixed in a stationary rack with the ability to adjust its angle of inclination within 30 - 60º, at the base of the rack, made in the form of a truncated trapezoid, the engine is located, connected on one side with the set speed of the housing, and on the other with a rotational mechanism that rotates the housing.

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