RU1799355C - Method of synthesis nitrogen-containing zeolite of pentasil type making - Google Patents

Abstract

Application: in zerlite and catalyst industries of the oil refining and petrochemical industries. Essence: the method includes preparing the reaction mixture by the interaction of sources (SI02, A1gO3) of silicon and aluminum oxides, alkali metal cations and organic nitrogen-containing compounds, homogenization, hydrothermal crystallization of the mixture, separation of the zeolite from the mother liquor, washing, drying. The mother liquor from the crystallization stage, containing an environmentally harmful organic nitrogen-containing component, is completely returned to the stage of preparation of the reaction mixture, and powdered amorphous silica is used as a source of silicon oxide. Amorphous silica powder contains 0.0001-1 wt.% Na20 and has a bulk density of 0.04-0.25 g / cm3. 2 tab. in C

Description

The invention relates to a method for producing zeolites and can be used in zeolite and catalyst industries of the refining and petrochemical industries.

The purpose of the invention is to improve the fractional composition of zeolite while maintaining its high degree of crystallinity and adsorption capacity, improving the environmental friendliness of the method and reducing the cost of zeolite.

The invention is as follows.

Powdered amorphous silica with a bulk density of 0.04-0.25 g / cm3 containing No. 200.0001-1 wt.% Mixed

with the mother liquor obtained from previous crystallization, solutions of sodium aluminate, alkali and the organic component are added to the resulting hydrogel. The reaction mixture is crystallized in autoclaves at a temperature of 150-175 ° C for 6-24 hours. After crystallization is completed, the zeolite is separated from the mother liquor, washed, dried and calcined at 50b-600 ° C for 10-16 hours. The resulting zeolite is characterized by phase composition (degree of crystallinity), adsorption capacity and fractional composition.

Phase composition of the obtained zeolite pentasil 95-100%, adsorption capacity

VI

u o

W

eaten eaten

with

for n-StZhE vapors - 0.17-0.18 cm3 / g, fraction fraction 8 microns - (90-98) wt.%, 4 microns - (74-90) wt.%, 2 microns - (34-75 ) wt.%.

The mother liquor, which is a mixture of silicon and sodium oxides, an organic nitrogen-containing component and water, is completely returned to the stage of preparation of the reaction mixture.

It is known from experience in filtering equipment at zeolite factories that as a result of a slip through the filter cloth, at least 5% of the resulting crystalline product enters the mother liquor, with the base having a crystal mass of at least 2 microns. When the mother liquor returns to the stage of preparation of the reaction mixture, this zeolite will act as seed crystals and help accelerate the zeolite formation reaction, as well as the formation of small crystals of uniform size.

The use of powdered amorphous silica as a source of silicon oxide allows the mother liquor to be completely returned to the stage of preparation of the reaction mixture and thereby eliminate production effluents containing an environmentally harmful nitrogen-containing component and reduce the cost of the product.

The use of liquid sources of silicon oxide, for example silica sol, leads to a change in the molar ratio of NaO / mol of Si02 in the reaction mixture from 24 to 34 during the first circulation of the mother liquor, from 34 to 44 during the second, etc. first, it will slow down and then terminate the zeolite formation reaction. In the case of using sodium silicate, in addition to the indicated, sodium salts also accumulate, because excess sodium hydroxide must be neutralized with strong acids.

The use of powdered amorphous silica with a bulk density of 0.04-0.25 g / cm is due to the fact that silica with a bulk density of less than 0.04 g / cm3 is not produced in industry, and when using silica with a bulk weight exceeding 0.25 g / cm, the rate of zeolite formation decreases and the adsorption capacity of the resulting zeolite decreases.

The content of sodium oxide, which is part of the powder of amorphous silica during the preparation of the reaction mixture, should not increase the content of No. 20 in the resulting zeolite (usually the zeolite contains 0.5-1.5 May.% NaaO), so that

the system did not accumulate due to the fact that the mother liquor completely returns to the synthesis process. The claimed technical solution differs from the prototype in that the mother liquor containing an environmentally harmful nitrogen-containing component is completely returned to the stage of preparation of the reaction mixture, and as a source

0 silicon oxide using amorphous silica with a bulk density of 0.04-0.25 g / cm3 and containing 0.0001-1.0 wt.% N320.

The economic effect of using the present invention consists in saving an organic compound, which is spent only on incorporation into the zeolite structure, and then reused.

0 PRI me R 1. 50 kg of aerosil (amorphous silica) grade A-300 (weighed 0.04 g / cm3) with a NaaO content of 0.0001 wt.% Mixed with 550 l of water, add to the resulting hydrogel 5.1 L aluminate solution

5 sodium (conc. By AlaOa - 297 g / l), 6.6 l of alkali solution (conc. By NaOH - 678 g / l) and 35 l of tr.butylamine. The reaction mixture was crystallized at 150 ° C. for 24 hours. The crystallized product was separated from

0 mother liquor, washed, dried and calcined at 540 ° C for 16 hours. Phase composition (degree of crystallinity) of the product pentasil 95%, adsorption capacity in pairs - 6.18 cm3 / g, content

5 fractions 8mk-80mass.%, 4mk-30mass.%, 2mk-10.5 wt.%.

The mother liquor containing 42 g / l tributylamine 6.5 g / l NaaO and 10 g / l SiOg are sent again to prepare react

0 tion mixture.

With me p2. 50 kg of aerosil grade A-300 (bulk density 0.04 t / cm3), NaaO - 0.0001 wt.% Are mixed with the mother liquor obtained in Example 1. 5.1 l of sodium aluminate is added to the hydrogel formed for 5 s. (conc. by ABOz - 297 g / l) and 6 l of tributylamine. The reaction mixture was crystallized at 150 ° C. for 12 hours. The crystallized product was separated from

0 mother liquor, washed, dried and calcined at 600 ° C for 10 hours. The phase composition of the obtained zeolite - pentasil - 100%, the adsorption capacity for n-CyHie pairs - 0.18 cm / g. Fraction content

5 8 microns - 96.7 wt.% 4 microns - 88.7 may. %, 2 microns -74.2 wt.%.

The mother liquor is used to prepare the reaction mixture.

PRI me R 3. 50 kg of aerosil grade A-175 (bulk density 0.12 g / cm) Ma-S 0.0001

wt% is mixed with the mother liquor obtained in Example 2. 5.1 L sodium aluminate solution (conc. 297 g / L) and Bl l tributylamine are added to the resulting hydrogel. The reaction mixture was crystallized at 175 ° C for 6 hours. The crystallized zeolite was separated from the mother liquor, washed, dried and calcined at 540 ° C for 16 hours. The phase composition of the obtained product — pentasil — 95% adsorption — on the capacity of n-SpNIB pairs of 0.18 cm3 / g. The content of the fraction 8 microns - 98 wt.%, 4 microns - 85 wt.%, 2 microns - 75.5 wt.%.

The mother liquor is returned to the step of preparing the reaction mixture.

PRI me R 4. 57 kg of white carbon black grade BS-120 (bulk density 0.25 g / cm3), the content of Na20 - 0.9 wt.% Is mixed with the mother liquor obtained in example 3. In the resulting suspension was added 5.1 liters of sodium aluminate (conc. by ABO3 - 297 g / l) and 6 l of tributylamine. The reaction mixture was crystallized at 160 ° C for 20 hours. The crystallized product was separated from the mother liquor, washed, dried and calcined at 550 ° C for 16 hours. The phase composition of the obtained product is 80% pentasil, the adsorption capacity in pairs is 0.16 cm3 / g. The content of the fraction is 8 microns-91.8 wt.%, 4 microns-74.9 wt.%, 2 microns - 34.1 mass%. The mother liquor is returned to the step of preparing the reaction mixture.

Example 5. 50 kg of aerosil grade A-175 (bulk density 0.12 g / cm3) MaaO - 0.0001 wt.%, Mixed with 550 l of water, 2.8 l of solution was added to the hydrogel obtained sodium aluminate (conc. according to A120z - 297 g / l), 6.6 l of alkali solution (conc., according to MaOH - 678 g / l) and 26.6 kg of tetrabutylammonium bromide. The reaction mixture is crystallized at 175 ° C for 18 hours. The crystallized product is separated from the mother liquor, washed, dried and calcined at 540 ° C for 16 hours. The phase composition of the obtained zeolite-pentasil is 100%, the adsorption capacity for STNT 0.18 cm3 / g. The content of the fraction 8 microns - 77 wt.%, 4 microns - 25.5 wt.%, 2; microns - 15 wt.%. The mother liquor containing 40 g / l tributylamine, 7.2 g / l NasO and 12.2% g / l SI02 is returned to the preparation stage of the reaction mixture.

PRI me R 6. 50 kg of aerosil grade A-175 (bulk density 0.12 g / cm3), MaaO - 0.0001 wt.% Is mixed with the mother liquor obtained in example 5. In the resulting hydrogel is added 2 8 L of a solution of sodium aluminate, 5.6 kg of tetrabugylammonium bromide. The reaction mixture is crystallized at 160 ° C for 20 hours. The crystallized product is separated from the mother liquor, washed, dried and calcined at 540 ° C for 16 hours. The phase composition of the obtained product is pentasil - 100%, adsorption capacity in pairs - 0 , 17 cm / g. The content of the fraction 8 microns is 98.2 wt.%, 4 microns is 89.3 wt.%, 2 microns is 72.5 wt.%. The mother liquor is returned to the step of preparing the reaction mixture.

Example 7. 50 kg of aerosil grade A-300 (bulk density 0.04 g / cm, NaaO - 0.0001 wt.% Is mixed with the mother liquor obtained in example 6. 5.1 l of aluminate solution is added to the hydrogel obtained sodium and 5.6 kg tetrasbutylammonium bromide.The reaction mixture is crystallized at 175 ° C for 6 hours, the crystallized product is separated from the mother liquor, washed, dried and calcined at 540 ° C for 16 hours. Phase composition pentasil 98%, adsorption capacity per param n - С7Ы1бО, 18с.m3 / g, content 8мк-98 wt.%, 4 microns - 90 wt.%, 2 microns - 70 wt.%. The mother liquor is used for preparation detecting the following reaction mixture.

Example 8. 51 kg of KSK silica gel chips (bulk density 0.45 g / cm3), N320 content of 1 wt% was suspended in the mother liquor obtained in Example 7. 4.8 l of sodium aluminate solution and 5 were added to the hydrogel obtained. 6 kg of tetrabutylammonium bromide. The reaction mixture is crystallized at 175 ° C for 24 hours. The crystallized zeolite is separated from the mother liquor, washed, dried and calcined at 540 ° C for 16 hours. The phase composition of the product is pentasil 55%, adsorption capacity 0.13 cm / g, fraction 8 mk-75 may.%, 4 mk-15 wt.%, 2 mk-4 wt.%.

Example p 9 (prototype). 5 L of a solution of sodium aluminate is mixed with 3.5 L of a solution of tributylamine. The resulting alkaline part is mixed with 0.35 l of aluminum sulfate solution with a concentration of (504) s - 220 g / l and 3.7 l of H2S04 s. concentration of 200 g / l. The resulting silica-alumina crystallizes at 150 ° C for 4 days. The crystallized product is separated from the mother liquor, washed, dried and calcined at 540 ° C for 16 hours. The phase composition of the product is pentasil 95% adsorption capacity for n-heptane pairs OL6 cm3 / g, fraction content 8 microns - 55%. 4 microns - 10%, 2 microns - 2%.

In the table. 1 shows a relative analysis of the quality of the zeolite obtained with the return of the mother liquor and the prototype.

The use of the mother liquor allows to improve the fractional composition of zeolite, while the content of fractions increases by 8 microns - by 39-43%, 4 microns by 64.5-80%, 2 microns - by 32-73.5%, and also reduce harmful emissions into the environment.

From the table. 1 it can be seen that the use of silica gel with a bulk density of more than 0.25 g / cm3, with a sodium oxide content of more than 1 wt.% (See Example 8) leads to a decrease in adsorption capacity by 20% and to a significant deterioration in the fractional composition.

In the table. 2 shows the costs of the organic component of the proposed method and the prototype.

From the data table. 2 shows that the economy of the organic component by the proposed method is 79-83%.

Claims (1)

SUMMARY OF THE INVENTION A method for producing a synthetic nitrogen-containing zeolite of the pentasil type, comprising mixing oxide sources silicon and aluminum, alkali metal cations and an organic nitrogen-containing compound, homogenization, hydrothermal crystallization of the mixture, separation of the zeolite from the mother liquor, washing and drying of the zeolite, in that, in order to improve the fractional composition of the zeolite while maintaining a high degree of crystallinity and adsorption capacity, to improve the environmental friendliness of the method and reduce the cost of zeolite, the mother liquor obtained by crystallization of the zeolite is returned to the mixing stage, and as a source of silicon oxide, powdered amorphous silica with a bulk density of 0.04-0.25 g / cm3 containing 0.0001-1.0 wt.% Na20 is used. The quality of the obtained zeolite Table 1 table 2