RU2629773C1 - Granular cracking catalyst manufacturing method - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method has been developed for preparation of granular catalyst, which comprises mixing zeolite powders Y (faujasite), natural aluminosilicates and binder, mixing, moulding, stabilisation and heat treatment. The method is characterized in that zeolites Y are used as a part of products for partial amorphisation of their mixtures with amorphous aluminosilicates, and the binder is a mixture of silicasole and aluminium oxochloride solutions in the ratio wt % (60-80):(20-40) by absolutely dry matter (a.d.m.). The starting mixtures of zeolite Y with amorphous aluminosilicates contain wt % 20-40 of zeolite Y with silicate module ≥5. The starting mixtures of zeolite Y with amorphous aluminosilicates are amorphizsd under thermocouple treatment conditions to residual zeolite content of wt % 5-15 with silicate module of 9-50. Silicazole is used with sodium oxide content of not more than wt % 0.7 andsilica content of 200-220 g/dm³. Aluminium oxochloride is used with composition of Al₂(OH)₅Cl with content of Al₂O₃ 48±4 wt % and water solution pH ≥3.5.

EFFECT: production of strong catalyst which produces gasoline with high octane number and reduced sulfur content, simplification of catalyst production process, and reduction of toxic gases emission when annealing the catalyst.

5 cl, 2 tbl, 1 dwg, 10 ex

Description

The present invention relates to oil refining, in particular catalytic cracking catalysts and methods for their preparation.

Granular cracking catalysts are known containing zeolites such as synthetic faujasite, beta and ZSM-5 dispersed in an inorganic oxide matrix consisting of synthetic aluminosilicates and clays.

It is known that the octane number of catalytic cracking gasoline increases with an increase in the silicate modulus of the faujasite (Y) zeolite, i.e. molar ratio of SiO ₂ / Al ₂ O ₃ .

(Yulius Scherzer, Designing FCC catalysts with high-silica Y zeolites, Applied Catalysis, 75, 1-32 (1991);

W-C Cheng, G. Kim, A.W. Peters, X. Zhao, K. Rajagopalan (Grace Davison), Environment Fluid Catalytic Cracking Technology, Catal. Rev. - Sci. Eng., 40 (1 @ 2), 39-79 (1998).

It is also known that the residual sulfur content in catalytic cracking gasoline depends on the specific activity of the amorphous matrix.

(US Pat. No. 5525210, 1996).

The effect of the properties of the amorphous aluminosilicate matrix in the composition of cracking catalysts on the yield and quality of the gasoline fraction, including the octane number and sulfur content, is known

(Hydrocarbon processing, February 1990, pp. 5-56).

The observed synergistic effect of the interaction of the matrix and zeolite is explained by the sequence of movement of the raw material molecules through the matrix and further to the zeolite crystals, which creates the conditions for a two-stage cracking process with a high conversion and a high yield of gasoline with an increased octane number and lower sulfur content.

In the synthesis of zeolite-containing cracking catalysts, synthetic and / or natural aluminosilicates, which are less active than zeolite, are used as an amorphous aluminosilicate matrix.

During the operation of cracking catalysts, including multiple cyclic high-temperature heating in an atmosphere of water vapor, the components of the matrix undergo changes, leading to a decrease in its activity and increased selectivity. At the same time, a deep degradation of the zeolite crystal lattice occurs with a decrease in the content of the crystallized phase, but with an increase in its silicate modulus, as well as with the formation of a part of the zeolite amorphized as a result of this process. Amorphization of the zeolite provides the forced movement of the raw material molecules to the remaining zeolite crystals through its amorphized part with larger pores. Product properties (gasoline yield, octane number, sulfur content) are the result of changes in the properties of the starting matrix and amorphization of the zeolite, including the content of the remaining zeolite and its silicate module, and the product of amorphization of the zeolite.

Known industrial granular cracking catalysts do not allow to obtain gasoline with an octane rating of MM / IM higher than 80/90 and residual sulfur content under operating conditions (temperature 450-475 ° C, specific feed rate 1.2-3.0 h ^-1 ) in gasoline below 5-10% of the content of sulfur compounds in the processed raw materials. See tab. 2 catalysts: No. 1 - BASF, No. 2 - Salavatnefteorgsintez, No. 3 - ISKhZK, Ishimbay, Bashkortostan.

The operational properties of the catalysts are determined by their composition and production method and are evaluated mainly by their bulk density, wear resistance and gasoline yield, its octane number and sulfur content.

Known methods for producing ball cracking catalyst based on zeolite Y (US Pat. RF No. 2221644, 2004, No. 2229933, 2004, No. 2221645, 2004, No. 2229498, 2003, No. 2233309, 2004, No. 2285562, 2006, No. 2287370, 2006, No. 2362796, 2009, No. 2405626, 2010; No. 2430955, 2011). These methods are based on mixing aqueous solutions of aluminum sulfate, sulfuric acid, sodium silicate, a suspension of zeolite Y powders in H-NH _4- REE or NH _4- REE forms with a silicate module of 4.6 ÷ 9.0, with the addition of kaolin clay and alumina with the formation of aluminosilicate zeolite-containing hydrosol, which further coagulates at 5-20 ° C and pH = 7.5-8.5 in a layer of mineral oil in a ball-shaped hydrogel. Then the hydrogel beads are treated with aqueous solutions of ammonium sulfate, aluminum sulfate, ammonium nitrate, REE nitrates, dried and calcined.

The disadvantage of these methods is the complex technology with the use of "wet" operations and a large volume of wastewater. The disadvantages of the catalyst in these methods also include low bulk density and abrasion resistance. Catalytic cracking gasoline has an octane rating of MM / MI no higher than 78/86 g and the sulfur content in gasoline is at the level of 50 ppm and higher.

A known method of producing granular cracking catalyst by mixing zeolite Y with module 6-10 with kaolin, thermally activated aluminum hydroxide and aluminum oxochloride, molding on a drum tabletting machine with a mixture moisture of 35-45%, followed by stages of tablet rolling on a horizontal plate pelletizer, low-temperature exposure the atmosphere of air (stabilization), drying and calcining the catalyst at a temperature of 550-650 ° C in a rotary calcining furnace (US Pat. RF №2517171, 2014). The method leads to a sharp increase in the resistance of granules to shock abrasion loads.

The disadvantages of the catalysts according to the described method is the low octane number of catalytic cracking gasoline (MM / IM not higher than 79/88) and an increased content of residual sulfur compounds (not less than 10% of the total sulfur content in the feed). The disadvantage of this method is the use of significant quantities of aluminum ixochloride at the stage of preparation of the charge, which leads to corrosion of the equipment at the stage of calcination and the release of gaseous HCL, which complicates the process and increases the cost of the process products.

The closest known solution to a similar problem in terms of technical nature and the achieved effect is a method for producing a granular cracking catalyst, comprising preparing a mixture by mixing the zeolite as a separate crystallized phase or as a mixture with amorphous aluminosilicate and / or clay, clay, a binder and an exhaustant in mass ratio (25-40) :( 40-50) :( 10-20) followed by molding by extrusion, stabilization, drying and calcination (US Pat. RF No. 2500472, 2013). As a binder, aluminum oxochloride is used. Calcined alumina and / or materials of natural origin are used as a depleting additive. The result is strong active catalysts. However, the octane number of gasoline produced is insufficient, and the content of residual sulfur compounds in gasoline is high. Another disadvantage of this method is the use of somewhat smaller than in the patent of the Russian Federation No. 2517171, but still significant quantities of aluminum oxochloride, which leads to environmental problems and corrosion of industrial equipment, and also increases the cost of processing.

The objective of the claimed technical solution is to create a method for producing a granular cracking catalyst, which allows to increase the octane number of gasoline and reduce the residual content of sulfur compounds in it, with a minimum decrease in the yield of the amount of light oil products, as well as reduce the amount of toxic gas emissions during calcination of the catalyst.

The problem is solved by the developed method for producing a granular catalyst, which includes mixing powders of zeolite Y (faujasite), natural aluminosilicates and a binder, mixing, molding, stabilization and heat treatment. The method is characterized in that they use zeolites Y as part of the products of partial amorphization of their mixtures with amorphous aluminosilicates, and the binder is a mixture of solutions of silica sol and aluminum oxochloride in the ratio (60-80): (20-40)% of the mass, based on absolutely dry substance (a .sv.).

The initial mixture of zeolite Y with amorphous aluminosilicates contain 20-40% of the mass. zeolite Y with silicate module ≥5.

The initial mixture of zeolite Y with amorphous aluminosilicates is subjected to amorphization under thermocouple treatment to a residual zeolite content of 5-15% of the mass. with silicate module 9-50.

Use silica sol with a sodium oxide content of not more than 0.7% by mass, and a silica content of 200-220 g / dm ³ .

Use aluminum oxochloride composition Al ₂ (OH) ₅ Cl with a content of Al ₂ O ₃ 48 ± 4% of the mass. and a pH of an aqueous solution of ≥3.5.

The ratio of powders of zeolite Y and / or its mixture with amorphous aluminosilicates, partially amorphized zeolite Y or its mixture with amorphous aluminosilicates, kaolin clay and an aqueous binder solution is, respectively, (0-28) :( 16-55) :( 35-40 ) :( 7.5-11.8)% of the mass. (for examples 2-10 table. 1).

Partially amorphized material is prepared by mixing the components and cyclic thermocouple treatment of the mixture. An analogue of a partially amorphized material is a spent partially or fully microspherical zeolite-containing cracking catalyst.

The technical result consists in obtaining a durable catalyst, which, under conditions close to the operating conditions of Thermofor-type plants, produces gasoline with an octane rating higher than 80/90 and a low sulfur content, simplifies the catalyst production technology, and also reduces the amount of toxic gas emissions during annealing.

The positive effect of the claimed technical solution is due to the introduction into the catalyst of two or more ReUSY zeolites in mixtures with amorphous aluminosilicate (the initial mixture and / or from amorphized material) to a total zeolite content of 8-12 wt%, one of which has a silicate module (9- 50), the introduction of a catalytically active product of the amorphization of zeolite, as well as the use of silicasol as part of a binder.

The use of partially amorphized zeolite-containing components with a residual ReUSY zeolite content of 5-15% by weight in the catalyst composition. with a silicate module 9-50 and a binder in the form of a mixture of silica sol - aluminum oxochloride upon receipt of a granular catalyst in the present method meet the criterion of "novelty."

The industrial applicability of the proposed method for the preparation of granular cracking catalyst is confirmed by the following examples:

Raw materials: powder materials

1. The initial mixture of 30% of the mass. zeolite ReHY with a module ≥5.0 with an amorphous aluminosilicate matrix, the analogue is the initial microspherical cracking catalyst (MS).

2. Partially amorphized material is the product of amorphization of the mixture according to claim 1, the residual zeolite content is 10-15%, the silicate module is 5-15. The analogue is a partially worked out microspherical cracking catalyst (MS-1).

3. Partially amorphized material is the product of amorphization of the mixture according to claim 1, the residual zeolite content is 5-10%, with a silicate module of 40-50. The analogue is the spent microspherical cracking catalyst (MS-2).

4. Alumina metallurgical GOO, RF, GOST 30558-98;

5. Kaolin enriched deposits of the Crane Log, RF, TU 5729-029-00284530-98, PPP = 12-14% of the mass;

6. Tripoli of the Zikeevsky quarry of refueling complex (bleaching earth (infusorian) of the Zikeevsky deposit), RF, TU 21-RF-239-02, “M-80”, RFP no more than 15.0% of the mass.

7. Silica sol Nanosil-20A (Szol), TU 2145-001-09020211-2013, aqueous solution; the content of silicon dioxide, g / DM ³ - 216; pH = 3.2; density at 20 ° C, g / cm ³ - 1.128; specific surface area, m ² / g - 229.68; average particle size, nm = 11.36

8. Aluminum oxochloride, RF (OXA), TU 2163-016-94262278-2010, grade 2: Mass fraction of the main substance in terms of Al ₂ O ₃ ,% - 48 ± 4;

Equipment:

1. Z-shaped mixer with a capacity of 1 dm ³ ;

2. Granulator FP-015 production of AO Dzerzhinsktekhnomash, RF;

3. Horizontal dishwasher;

4. Drying cabinet;

5. The muffle furnace;

6. Installation for testing ball cracking catalysts, OST 38.01176-7-79;

7. Installation for thermocouple stabilization of cracking catalysts, OST 38.01176-79;

8. Laboratory device for determining the octane number of catalytic cracking gasoline OKTAN-1M, Ukraine, Plus Radio, Kiev.

A set of indicators of the catalysts:

1. Bulk density, kg / dm ³ ;

2. The pore volume, cm ³ / g;

3. Resistance to shock abrasion (installation Rental);

4. Activity in the cracking process of vacuum gas oil.

Below are examples of the implementation of the proposed technical solution, with which it is illustrated, but not exhausted.

The mass ratio of the components, the conditions for the preparation of molding sand are given in table. 1 pp 2-10 (p. 1 - prototype).

Example 1, table. 1 (Prototype). Prepare a mixture of MS powder (without using cyclic thermocouple treatment of the mixture) containing 30% of the mass. zeolite, 20% of the mass, alumina GOO and 40% of the mass. kaolin, which is stirred in a kneading machine for 15 minutes The mixture is introduced 10% of the mass. OXA in the form of an aqueous solution and continue mixing for 25 minutes. The prepared mass is formed on a screw granulator equipped with a cutting device into granules 6 × 6 mm in size, and spread on baking sheets for stabilization at room temperature for 16-18 hours.

After stabilization, the granules are doused for 2 hours, moistening the layer with water spray, or further dried without rolling the granules.

The catalyst is dried in an oven at a temperature of 100-120 ° C for 5-6 hours and calcined in a muffle furnace 550-650 ° C for 5-6 hours.

Bulk density is determined in the finished catalyst, OST 38.01776-79, p. 4.2, kg / m ³ , pore volume (% wt.), Pellet strength by the rental method, TU 2177-10-40431454-2003, p. 5.3,% / 300 sec

The catalytic activity is determined during the cracking of vacuum gas oil At a temperature of 460 ° C, fixing the output of gas, gasoline, light gas oil, heavy gas oil, the total conversion of raw materials,% of the mass, the octane number of gasoline MM / IM and the sulfur content of gasoline. The catalytic activity of the sample is determined after its thermocouple stabilization at 750 ° C for 6 hours, 100% steam.

The quality indicators of the catalyst (prototype) are given in table. 1 p. 1 and in table. 2 p. 4.

Examples 2-10 (table. 1, claimed). Powdered components (MS, MS-1, MS-2, TZK and kaolin) are mixed in a kneading machine for 15 minutes. At the same time, a binder is prepared at the ratios indicated in the table. 1. OXA is prepared by dissolving OXA powder in water, then mix the OXA solution and Szol immediately before use. The composition of the mass by molding is given in table. one.

The binder solution is introduced into the powder mixture and the mass is continued to mix for 25 minutes, after which it is transferred to a granulator and 6 × 6 mm catalyst granules are formed. The granules are stabilized for 16-18 hours and dipped in a drum pelletizer for 2 hours with water spray, dried in an oven at 100-120 ° C for 5-6 hours and calcined in a muffle furnace at 550-650 ° C for 5-6 hours

The finished catalyst is tested according to the program of Example 1.

The operational characteristics of the catalysts in examples 2-10 are given in table. 2 pp. 5-15. In the same place, in table. 2, the data for the prototype (paragraph 4) and known serial industrial catalysts (paragraphs 1-3) are given.

From the table. 1, 2 it is seen that the use of MS-1 and MS-2 in the composition of the catalyst allows to obtain a strong active catalyst. The gasoline yield is slightly lower compared to the prototype, however, it has an increased octane number (from 80/90 units to 84/94) and a lower residual sulfur content (up to 13-19 ppm, i.e. less than 5% of the sulfur content in the cracking feed). At the same time, gasoline in the amount of light has an octane number, which allows it to be used as a commercial product.

From the table. 1, 2 it is seen that the valuable properties of the catalytic cracking gasoline obtained on the catalysts according to the claimed method, namely, an increase in the octane number by 2-5 points and a half reduction in its sulfur content, are achieved by introducing a smaller amount (or completely without using) of the initial zeolite Y and / or the initial microspherical catalyst MS, without the use of an expensive depleting additive (calcined finely divided alumina, etc.). It also allows you to simplify the technology and reduce the cost of the catalyst.

Evaluation of the effectiveness of the catalysts according to the proposed method in terms of the ratio of octanotons to 1% of the mass. zeolite in the composition of the catalyst (see Fig.) leads to an unambiguous conclusion on the feasibility of industrial application of the proposed method.

Claims (5)

1. A method of producing a granular cracking catalyst by mixing powders of zeolites Y, natural aluminosilicates and a binder, mixing, molding, stabilization and heat treatment, characterized in that they use zeolites Y as part of the products of partial amorphization of their mixtures with amorphous aluminosilicates, and the binder is a mixture of silica sol solutions and aluminum oxochloride in a ratio of (60-80) :( 20-40) wt.% on absolutely dry matter. 2. The method according to p. 1, characterized in that the initial mixture of zeolite Y with amorphous aluminosilicates contain from 20 to 40 wt.% Zeolite with a silicate module of ≥5. 3. The method according to p. 1 or 2, characterized in that the initial mixture of zeolite Y with amorphous aluminosilicates is subjected to amorphization under thermocouple treatment to a residual zeolite content of 5-15 wt.% With a silicate module of 9-50. 4. The method according to p. 1, characterized in that they use silica sol with a sodium oxide content of not more than 0.7 wt.% And a silica content of 200-220 g / dm ³ . 5. The method according to p. 1, characterized in that they use aluminum oxochloride of composition Al ₂ (OH) ₅ Cl with an Al ₂ O ₃ content _of 48 ± 4 wt.% And an aqueous solution pH of ≥3.5.

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