RU2473384C1 - Microspheric bizeolite catalyst for increasing octane number of petrol of vacuum gas oil cracking and method of its preparation - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: claimed invention relates to catalyst and method of preparing microspheric bizeolite catalyst of vacuum gasoil cracking. Described is catalyst, including ultrastable zeolite Y with matrix constant from 24.30 to 24.55 Å and content of rare earth elements 3.0-6.0 wt %, zeolite HZSM-5 with silica module from 25 to 40 and matrix, in which as components used are bentonite clay, aluminium hydroxide and amorphous alumosilicate. Catalyst contains in wt %:zeolite Y 15-25; zeolite HZSM-5 1-5; bentonite clay 15-30; aluminium hydroxide 15-30; amorphous alumosilicate 20-45. Also disclosed is method of preparation of said catalyst, including application of zeolite Y with matrix constant from 24.30 to 24.55 Å, carrying out ionic exchanges on ammonium cations and rare earth elements on zeolite Y until content of rare earth elements in zeolite is 3.0-6.0 wt %, ammonium 7.0-8.0%, zeolite ultrastabilisation in water vapour medium, after ultrastabilisation third ionic exchange on ammonium cations and further mixing of zeolite with matrix components are carried out.

EFFECT: simultaneous increase of petrol output and octane number of cracking petrol.

2 cl, 2 tbl, 8 ex

Description

The present invention relates to the refining industry, namely, the preparation of microspherical cracking catalysts for vacuum gas oil to increase the octane number of cracked gasoline.

A traditional vacuum gas oil cracking catalyst does not allow both a high yield of cracked gasoline and high octane numbers of cracked gasoline to be obtained.

A known catalyst and method for the preparation of cracking catalysts based on ultrastable zeolite type HY, amorphous aluminosilicate and kaolin [US Patent No. 4826793, 1989; No. 3957689, 1976; No. 3402996, 1968]. Ultra-stabilization of the ammonium form of the zeolite is carried out in a medium of 100% water vapor at temperatures from 538 to 816 ° C. to obtain a zeolite having a lattice module in the range from 7.0 to 12.0. The disadvantage of this method is to reduce the crystallinity of the zeolite when it is ultra-stabilized at high temperatures, low activity of the resulting catalyst and low octane numbers of cracked gasoline.

A known catalyst and method for its preparation using medium-pore (type ZSM-5) and broad-porous zeolites (type Y) for cracking a gasoline fraction or heavy crude oil [US Patent No. 7326332, 2008]. The disadvantage of this catalyst is the low yield of the gasoline fraction.

A known catalyst (US patent No. 4309280), in which ZSM-5 zeolite in hydrogen form was used as an additive to the cracking catalyst in an amount of 0.01-1.00 wt.% Of the total weight of the catalyst. The disadvantage of this invention are the low octane numbers of cracked gasoline.

A known catalyst (US patent No. 3758403) containing zeolite ZSM-5 and broad-porous zeolite (for example, zeolite X or zeolite Y) as active components, which manifested itself in a simultaneous increase in the octane number of gasoline and an increase in the yield of C ₃ -C ₄ olefins by 10 wt. .%. The disadvantage of this invention is the low yield of cracked gasoline.

A known catalyst (US patent No. 5380690) containing a mixture of zeolite from the ZSM-5 family and zeolite Y as active components, which influenced the simultaneous increase in the octane number of gasoline and the yield of C ₂ -C ₄ olefins, especially C ₃ -C ₄ olefins. The matrix of this catalyst was a mixture of halloysite and aluminum hydroxide pseudoboehmite modification. The disadvantage of this catalyst is the low yield of gasoline.

It is known the use of two types of zeolites - ultrastable zeolite Y and zeolite HZSM-5 in the catalyst and the method of its preparation (RF patent 2365409). The catalyst is designed for deep cracking of oil fractions in order to obtain a high yield of C ₂ -C ₄ olefins.

Closest to the proposed is a catalyst for cracking oil fractions and a method for its preparation (RF patent 2300420, prototype). The known catalyst contains ultrastable zeolite Y as an active component, and a mixture of bentonite clay, amorphous aluminosilicate and aluminum hydroxide as a matrix. The catalyst is prepared by conducting ion exchanges for cations of rare-earth elements and ammonium on NaY zeolite, ultra-stabilization of the zeolite in water vapor, mixing the zeolite with matrix components, followed by spray drying of the obtained composition from zeolite and matrix components, calcining and obtaining a catalyst. The disadvantage of this catalyst is the low octane number of cracked gasoline.

An object of the present invention is to provide a vacuum gas oil cracking catalyst providing a high yield of cracked gasoline and a high octane number of cracked gasoline.

This goal is achieved through the use of two types of zeolites in the catalyst - ultra-stable zeolite Y with a low lattice constant of the zeolite and a low content of rare earth elements, which reduces the rate of hydrogen redistribution and leads to an increase in the octane number of cracked gasoline, as well as HZSM-5 zeolite at low its content in the catalyst, which allows moderate cracking of normal cracked gasoline paraffins, which have low octane values. Thus, the yield of cracked gasoline is slightly reduced, but its octane number is increasing.

The proposed catalyst for cracking vacuum gas oil contains ultra-stable zeolite Y in cation-decationized form with a lattice constant of the zeolite from 24.30 to 24.55 Å, zeolite HZSM-5 with a silica module from 25 to 40, and bentonite clay is used as matrix components, amorphous aluminosilicate and aluminum hydroxide in the following components, wt.%: zeolite Y 10-25; zeolite HZSM-5 1-5; bentonite clay 15-30; aluminum hydroxide 15-30; amorphous aluminosilicate 20-45.

The proposed method for the preparation of a catalyst for cracking vacuum gas oil includes ion exchanges for cations of rare earth elements and ammonium on zeolite Y, ultrastabilization of zeolite in water vapor, mixing zeolite Y with a suspension of zeolite HZSM-5 and matrix components to obtain a composition, spray drying the resulting composition from zeolite and matrix components, followed by calcining and obtaining a catalyst, moreover, bentonite clay, amorphous aluminosilicate and . Idroksid aluminum with the following component, in weight%: zeolite Y 10-25; zeolite HZSM-5 1-5; bentonite clay 15-30; aluminum hydroxide 15-30; amorphous aluminosilicate 20-45. Before the stage of ultrastabilization of the zeolite, ion exchanges are carried out to a content of rare earth elements in the zeolite of 3.0-6.0 wt.%, Ammonium up to 7.0-8.0%. After the stage of ultrastabilization, a third ion exchange for ammonium cations is carried out.

Zeolite Y is a powder with a particle size of 0.2-0.8 microns. The lattice constant of the zeolite is from 24.30 to 24.55 Å. The lattice constant of type Y zeolite is determined by x-ray phase analysis. Zeolite is used in REE-N form, the content of rare earth elements is from 3.0 to 6.0 wt.% In terms of oxides of rare earth elements, the content of sodium oxide should be less than 1.5 wt.%

Zeolite HZSM-5 is a white crystalline powder with a particle size of less than 2 microns. The silica module of the zeolite is determined by chemical analysis. The content of sodium oxide should be less than 0.3 wt.%. Zeolite is used in the H-form.

The method of preparation of the catalyst is as follows. Bentonite clay is subjected to activation by ammonium nitrate according to the ion exchange method to reduce the content of sodium oxide. After activation, the residual content of sodium oxide in the clay is less than 0.2 wt.%. A suspension of the precipitated aluminum hydroxide is treated with concentrated nitric acid to peptize it. At this stage, part of the aluminum hydroxide is converted into basic nitric salts of aluminum, which ensures the strength of the resulting catalyst composition. Then mixed suspensions of activated bentonite clay and reprecipitated aluminum hydroxide in the required proportion. The main requirement for the implementation of this stage is the homogeneous mixing of the two suspensions.

The synthesized zeolite NaY is subjected to double ion exchange for cations of rare earth elements and ammonium so that the zeolite before the stage of ultrastabilization contains 3.0-6.0 wt.% Of rare earth elements (in terms of oxides) and 7.0-8.0 wt. % ammonium. The indicated content of rare-earth elements in the zeolite ensures the preservation of the crystallinity of the zeolite during its ultra-stabilization, and the content of ammonium cations before the ultra-stabilization stage and the temperature of the ultra-stabilization process provide zeolite with a given zeolite lattice constant. Ultrastabilization of the zeolite is carried out in water vapor at temperatures from 450 to 650 ° C for 1 to 5 hours. Upon completion of the ultrastabilization process, the zeolite is subjected to a third ion exchange for ammonium cations.

The use of ZSM-5 zeolite with a silica module of 25 to 40 makes it possible to have a low content of this zeolite in the catalyst, since with a low silica module, this type of zeolite is characterized by its high catalytic activity.

Suspensions of zeolite Y and zeolite HZSM-5 are added to the prepared composition bentonite clay - aluminum hydroxide - amorphous aluminosilicate. The mixture is filtered, molded into microspherical particles with a size of less than 0.25 mm. The resulting catalyst was dried and calcined.

Catalytic tests are carried out in a flow-through laboratory apparatus MAK-2M in accordance with ASTM D 3907-03 with a fixed catalyst bed. The reactor system was purged with nitrogen at a rate of 30 ml / min. The catalyst was loaded in an amount of 5 g. Hydrocarbon feed was dosed for 30 s. Activity in this case is estimated as the degree of conversion of raw materials in the given standard conditions. Before testing, the catalysts were treated with 100% water vapor at a temperature of 760 ° C for 5 hours.

The composition of the gaseous cracking products (C ₁ -C ₅₊ ), as well as the purge gas content (N ₂ ), were determined chromatographically. The Crystal 5000.1 chromatograph is equipped with an HP-PLOT Al ₂ O ₃ "S" capillary column (50 m × 0.537 mm × 15.00 μm, stationary phase HP-Al / S), a steel packed column (3 m × 3 mm, NaX adsorbent fraction 45/60), a flame ionization detector and a thermal conductivity detector.

Quantitative analysis of liquid products was carried out in accordance with ASTM D 2887 (simulated distillation method) on a GC-2010 chromatograph (Shimadzu) with an Rtx-2887 capillary column (10 m × 0.53 mm × 2.65 μm, the stationary phase was dimethyl polysiloxane) and flame ionization detector. All hydrocarbons that boil up to 216 ° C belonged to the gasoline fraction.

The content of coke deposits on the spent catalyst was determined by the weight loss of the sample aged at 150 ° C after sequential calcination at 500 (1 h) and 550 ° C (1 h).

The properties of the vacuum gas oil used for testing the catalysts are shown in table 1.

Table 1. Properties of Vacuum Gas Oil Raw material quality indicators Vacuum gas oil Density at 20 ° C, g / ml 0.899 Fractional composition according to ASTM D-2887 (° C): 288 n.k. 357 10% 434 fifty% 523 90% 546 95% 561 (98%) c.k. Sulfur content, wt.% 0.24 Conradson coking ability, wt.% 0.180 Group chemical composition, wt.%: paraffin-naphthenic content 46.0 fractions 52.0 aromatic content 2.0 resin content

The test results in accordance with the method ASTM D-3907 described catalysts are shown in table 2.

The following examples are provided to illustrate the invention.

Example 1 (prototype)

The following components are used in the preparation of the catalyst:

- a suspension of bentonite clay with a concentration of solid substance of 10.0 wt.%;

- a suspension of precipitated aluminum hydroxide pseudoboehmite modification with a concentration of 10.0 wt.% in terms of Al ₂ About ₃ ;

- a suspension of amorphous aluminosilicate with a solid concentration of 11 wt.%;

- a suspension of ultra-stable zeolite Y with a lattice constant of the zeolite of 24.65 Å and containing 15 wt.% solid. The content of rare earth elements before the stage of ultra-stabilization is 8.2 wt.%. The content of ammonium cations before the stage of ultrastabilization is 9 wt.%.

The suspensions are mixed in proportion so that the content of ultra-stable zeolite in the composition is 20 wt.%, Reprecipitated aluminum hydroxide is 18 wt.% In terms of Al ₂ O ₃ , amorphous aluminosilicate 40 wt.% And bentonite clay 22 wt.%

The resulting suspension is filtered, formed into microspherical particles with a size of less than 0.25 mm The catalyst is dried at a temperature of 100 ° C and calcined at 550 ° C.

The catalyst has a high gasoline yield, but the octane rating of cracked gasoline is low.

Example 2 (prototype)

The preparation of the catalyst is carried out as in example 1, the difference is that ultrastable zeolite Y has a lattice constant of zeolite 24.50 Å. The content of rare-earth elements before the stage of ultra-stabilization is 6.2 wt.% The content of ammonium cations before the stage of ultra-stabilization is 5.0 wt.%

The catalyst has a high gasoline yield, but the octane rating of cracked gasoline is low.

Example 3. It characterizes the preparation of the catalyst according to the proposed method.

The preparation of the catalyst is carried out as in example 1, the difference is that ultrastable zeolite Y has a lattice constant of zeolite 24.30 Å. The content of rare earth elements before the stage of ultrastabilization is 3.0 wt.%. The content of ammonium cations before the stage of ultrastabilization is 7 wt.%.

Additionally, zeolite HZSM-5 is introduced so that the catalyst has the following component composition (in wt.%):

- ultra stable zeolite Y-20

- zeolite HZSM-5 with a silica module equal to 25-1

- bentonite clay - 22

- amorphous aluminosilicate - 40

- reprecipitated aluminum hydroxide - 17.

The catalyst has a high yield of gasoline, the octane number of cracked gasoline rises.

Example 4. It characterizes the preparation of the catalyst according to the proposed method.

The preparation of the catalyst is carried out as in example 3, the difference is that ultrastable zeolite Y has a lattice constant of the zeolite of 24.55 Å. The content of rare earth elements before the stage of ultrastabilization is 6.0 wt.%. The content of ammonium cations before the stage of ultra-stabilization is 8.0 wt.%.

Additionally, zeolite HZSM-5 is introduced so that the catalyst has the following component composition (in wt.%):

- ultra stable zeolite Y-20

- zeolite HZSM-5 with a silica module equal to 25.9-2

- bentonite clay - 22

- amorphous aluminosilicate - 40

- reprecipitated aluminum hydroxide - 16.

The catalyst has a high yield of gasoline, the octane number of cracked gasoline rises.

Example 5. It characterizes the preparation of the catalyst according to the proposed method.

The preparation of the catalyst is carried out as in example 3, the difference is that the ultrastable zeolite Y has a lattice constant of the zeolite 24.40 Å. The content of rare earth elements before the stage of ultrastabilization is 5.0 wt.%. The content of ammonium cations before the stage of ultrastabilization is 7.5 wt.%.

Additionally, zeolite HZSM-5 is introduced so that the catalyst has the following component composition (in wt.%):

- ultra stable zeolite Y-17

- zeolite HZSM-5 with a silica module equal to 40-3

- bentonite clay - 20

- amorphous aluminosilicate - 30

- reprecipitated aluminum hydroxide - 30.

The catalyst has a high yield of gasoline, the octane number of cracked gasoline rises.

Example 6. It characterizes the preparation of the catalyst according to the proposed method.

The preparation of the catalyst is carried out as in example 3, the difference is that the ultrastable zeolite Y has a lattice constant of zeolite 24.30 Å. The content of rare earth elements before the stage of ultrastabilization is 3.0 wt.%. The content of ammonium cations before the stage of ultrastabilization is 8 wt.%.

Additionally, zeolite HZSM-5 is introduced so that the catalyst has the following component composition (in wt.%):

- ultra stable zeolite Y-25

- zeolite ZSM-5 with a silica module equal to 35.6-3

- bentonite clay - 15

- amorphous aluminosilicate - 42

- reprecipitated aluminum hydroxide - 15.

The catalyst has a high gasoline yield and a high octane number of cracked gasoline.

Example 7. It characterizes the preparation of the catalyst according to the proposed method.

The preparation of the catalyst is carried out as in example 3, the difference is that ultrastable zeolite Y has a lattice constant of zeolite 24.30 Å. The content of rare earth elements before the stage of ultrastabilization is 3.0 wt.%. The content of ammonium cations before the stage of ultra-stabilization is 8.0 wt.%.

Additionally, zeolite HZSM-5 is introduced so that the catalyst has the following component composition (in wt.%):

- ultrastable zeolite Y-15

- zeolite HZSM-5 with a silica module equal to 25.4-5

- bentonite clay - 15

- amorphous aluminosilicate - 45

- reprecipitated aluminum hydroxide - 20.

The catalyst has a low gasoline yield and a high octane number of cracked gasoline.

Example 8. It characterizes the preparation of the catalyst according to the proposed method.

The preparation of the catalyst is carried out as in example 3, the difference is that the ultrastable zeolite Y has a lattice constant of the zeolite of 24.45 Å. The content of rare earth elements before the stage of ultrastabilization is 3.0 wt.%. The content of ammonium cations before the stage of ultra-stabilization is 8.0 wt.%.

Additionally, zeolite HZSM-5 is introduced so that the catalyst has the following component composition (in wt.%):

- ultrastable zeolite Y-15

- zeolite HZSM-5 with a silica module equal to 35.6-5

- bentonite clay - 30

- amorphous aluminosilicate - 20

- reprecipitated aluminum hydroxide - 30.

The catalyst has a low gasoline yield and a high octane number of cracked gasoline.

Thus, as follows from the examples and table 2, samples containing only one zeolite, provide increased formation of gasoline, but the octane number of cracked gasoline is low. To achieve simultaneously high yields of gasoline and the octane number of cracked gasoline, it is necessary to introduce HZSM-5 zeolite into the catalyst when its content in the catalyst is from 1.0 to 5.0 wt.%.

table 2 Catalytic properties of catalyst samples At-
measures The content of zeolite type Y, wt.% The content of zeolite type ZSM-5, wt.% Lattice constant of zeolite type Y, Å Silica zeolite module type ZSM-5 The yield of gasoline, wt.% Octane number of gasoline, motor method one twenty 0 24.65 - 54,2 80.5 2 twenty 0 24.50 - 53.1 80.8 3 twenty one 24.30 25.0 52.9 81.1 four twenty 2 24.55 25.9 52.6 82.0 5 17 3 24.40 40,0 52.0 82.5 6 25 3 24.30 35.6 53,4 83.0 7 fifteen 5 24.30 25,4 51.8 83.1 8 fifteen 5 24.45 35.6 52.3 82.9

Claims (2)

1. A microspherical biceolite catalyst for increasing the octane number of vacuum gas oil cracking gasoline, including ultra-stable zeolite Y in cation-decation form and a matrix using bentonite clay, aluminum hydroxide and amorphous aluminosilicate as components, wherein the ultra-stable zeolite contains 3.0 -6.0 wt.% Rare earth elements and has a lattice constant from 24.30 to 24.55 Å, the catalyst additionally contains HZSM-5 zeolite with a silica module from 25 to 40, with the following content nents, wt.%:
zeolite Y 15-25 zeolite HZSM-5 1-5 bentonite clay 15-30 aluminum hydroxide 15-30 amorphous aluminosilicate 20-45 2. A method of preparing a microspherical biceolite catalyst to increase the octane number of vacuum gas oil cracking gasoline, including ion exchanges for ammonium cations and rare earth elements on zeolite Y, ultrastabilization of zeolite in water vapor, mixing zeolite with matrix components, using bentonite clay, aluminum hydroxide and amorphous aluminosilicate, obtaining a composition and spray drying, followed by calcination and obtaining a catalyst, characterized in that they use zeolite Y with a lattice constant of 24.30 to 24.55 Å, before the stage of ultra-stabilization, ion exchange is carried out until the content of rare-earth elements in the zeolite is 3.0-6.0 wt.%, ammonium 7.0-8.0%, after ultrastabilization carry out the third ion exchange for ammonium cations, at the stage of mixing the zeolite with matrix components, HZSM-5 zeolite with a silica module of 25 to 40 is additionally introduced, and the content of components is, wt.%:
zeolite Y 15-25 zeolite HZSM-5 1-5 bentonite clay 15-30 aluminum hydroxide 15-30 amorphous aluminosilicate 20-45