CN1098130A - A kind of cracking catalyst and preparation method thereof - Google Patents

Abstract

A catalytic cracking catalyst containing a composite aluminum-based binder is composed of 20-80m% clay, 5-40m% composite aluminum-based binder, 0-5m% oxides of elements selected from Sn, Ti, Mg, etc., 5-40m% selected from faujasite with a unit cell constant of 2.432-2.472nm, Composition of ZSM-5 zeolite, beta zeolite and their mixture. its preparation method It is to mix clay and deionized water for beating, add hydrochloric acid to acidify, add Pseudoboehmite, aluminum sol, zeolite molecular sieve beating, drying and washing Or roast that is the product. The catalyst in terms of activity, strength, gasoline yield There are improvements in other aspects, and at the same time, the coke in the reaction product is significantly reduced few.

Description

The invention relates to the technical field of cracking catalysts, in particular to a catalytic cracking catalyst containing a composite aluminum-based binder and a preparation method thereof.

With the continuous heaviness and inferiority of catalytic cracking raw materials, and the increasing demand for unleaded high-octane gasoline in the environmental protection system, the catalyst tends to develop into an ultra-stable Y molecular sieve cracking catalyst with a high molecular sieve content. At the same time, due to The increase in the weight of raw materials also puts forward new requirements for the ability of catalytic cracking catalysts to crack macromolecules. The substrate of the catalyst has a very important impact on the wear resistance, activity, and selectivity of the catalyst, especially the ability to crack macromolecules. U.S. Patent 4010116 proposes that the fluid catalytic cracking catalyst made of peptized pseudo-boehmite as a binder has good wear resistance and hydrothermal stability, while U.S. Patent 4325845 thinks that it is made of pseudo-boehmite Activated alumina is easy to promote coke production. Although peptized pseudo-boehmite has good bonding performance and certain activity, with the adoption of high silicon-aluminum ratio molecular sieves with small unit cell, less number of acid centers and low hydrogen transfer activity, the molecular sieve in the catalyst The added amount increases obviously, so the requirement for the bonding ability of the binder is higher, and the peptized pseudo-boehmite cannot fully meet this requirement. Using aluminum sol with better bonding performance as the binder of the cracking catalyst can improve the wear resistance of the catalyst (GB2109696, USP4542118), but the catalyst carrier prepared with aluminum sol as the binder has low cracking activity and the ability to crack macromolecules limited. In 1979, Filtrol Corporation mentioned in US Patent No. 4,206,085 the use of two kinds of pseudo-thin water alumina with different flow properties, one of which is used as a binder to improve the strength of the catalyst, and the other is used to adjust the activity of the catalyst. In 1982, Filtrol proposed in US Patent No. 4,325,847 that adding alumina to the cracking catalyst could improve the stability of zeolite. In this catalyst, in addition to pseudo-thin water alumina, anionized aluminum source gel was also introduced.

The object of the present invention is to provide a catalytic cracking catalyst containing a composite aluminum-based binder and a preparation method thereof. The composite aluminum-based binder combined with peptized pseudo-boehmite and aluminum sol can combine the characteristics of peptized pseudo-boehmite with certain cracking activity and good bonding performance with aluminum sol, and the reaction product produces less coke. Advantages in one, to improve catalyst wear resistance, activity and coke selectivity.

Said catalyzer of the present invention is made up of following components:

(1) 20-80m%, preferably 30-70m% clay;

(2) 5-40m%, preferably 10-30m% composite aluminum-based binder (based on Al ₂ O ₃ burning base);

(3) 0-5m% oxides selected from Sn, Ti, Mg, Zr, P, Mn, Cr;

(4) 5-40m%, preferably 10-40m%, selected from faujasite, ZSM-5 zeolite, beta zeolite and mixtures thereof having a unit cell constant of 2.432-2.472.

The content of each component of the catalyst mentioned in the present invention refers to the calcined base content of roasting at 800°C for 1 hour. The preparation method of the catalyst is to mix clay and deionized water for beating, add hydrochloric acid to acidify, and then add pseudoboehmite Stone, aluminum sol, zeolite molecular sieve beating, obtain the said catalyst of the present invention through steps such as drying, washing or roasting, and its preparation step comprises:

(1) According to the composition ratio of the catalyst in the present invention, clay and deionized water were mixed and beaten for 25-35 minutes, hydrochloric acid was added for acidification for 0.5-1 hour, and pseudo-boehmite was added for stirring and beating for 25-35 minutes, wherein the water The amount of hydrochloric acid added is based on maintaining a solid content of 20-55m%, and the amount of hydrochloric acid added accounts for 15-50m% of the base amount of pseudo-boehmite Al ₂ O ₃ ;

(2) Aging at 50-80°C for 0.5-2 hours;

(3) Add aluminum sol and stir for 10-20 minutes;

(4) Add the ground zeolite molecular sieve and continue beating for 25-35 minutes;

(5) dry forming;

(6) The product can be obtained after washing and drying, or can be obtained by roasting at 500-700°C for 1-3 hours.

Said composite aluminum-based binder of the present invention is the mixture of peptized pseudo-boehmite and aluminum sol, and its mixing weight ratio is 9: 1-1: 9, preferably 7: 3-3: 7 (with Al ₂ O ₃ burning base is the basis for calculation).

The faujasite with a unit cell constant of 2.432-2.472 nm in the present invention refers to REY, REHY, USY, REUSY and various Y zeolites with a high silicon-aluminum ratio.

The clay in the present invention refers to various clays that can be used as catalyst carriers such as kaolin, bentonite, rectorite, sepiolite and the like.

Compared with the prior art, the present invention has the following advantages:

1, the said catalytic cracking catalyst containing composite aluminum-based binder of the present invention, its wear resistance is better than the catalyst with a single peptized pseudo-boehmite as binder, as the wear index of the catalyst of the present invention is 2.0 -2.5% h ^-1 , the latter is 2.5-5.0% h ^-1 ; when cracking reaction is carried out, the coke selectivity of the former is better than that of the latter.

2. The activity of the catalyst of the present invention is better than that of a catalyst with a single aluminum sol as a binding agent. When cracking reaction is carried out, under the same situation of agent/oil ratio, the former is 2-5 times higher than the latter in the production rate of gasoline. percentage points, the heavy oil conversion capacity increased by 1-3 percentage points.

The following examples will further illustrate the present invention.

(1) Analytical testing method used in the present invention:

1. Na ₂ O content: determined by flame atomic absorption spectrometry.

2. Fe content: atomic absorption spectrometry.

3. RE ₂ O ₃ content: X-ray fluorescence spectrometry.

4. Determination of catalyst wear index: put a certain amount of catalyst into the wear index measuring device, blow and grind for 5 hours under constant air flow, except for the first hour, the fine powder less than 15 microns produced in the last four hours accounts for The weight percentage of the catalyst whose sample is larger than 15 microns is called the wear rate of the catalyst, also known as the wear index, and the unit is % h ¹ .

(2) Place of origin and specifications of raw materials used in the examples of the present invention:

1. Kaolin: Suzhou Jixuan 2#, produced by Suzhou Porcelain Clay Company.

2. Hydrochloric acid: chemically pure, Beijing No. 2 Chemical Reagent Factory.

Industrial pure, Beijing Organic Chemical Factory.

3. Pseudoboehmite: Shandong Aluminum Plant, wherein β trihydrate Al ₂ O ₃ <5m%.

4. Aluminum sol: Zhoucun Catalyst Factory, Al ₂ O ₃ content is 21.5-23.5m%, Al/Cl (m) is 1.15-1.25, Fe content is 0.025-0.07m%.

5. NH ₄ Y molecular sieve: Zhoucun Catalyst Factory, is a high silicon Y molecular sieve with a unit cell constant of 2.450nm.

6. REY molecular sieve: Zhoucun Catalyst Factory, unit cell constant 2.470nm, RE ₂ O ₃ 18.0m%, Na ₂ O 1.6m%.

7. ZSM-5 molecular sieve: produced by Zhoucun Catalyst Factory, SiO ₂ /Al ₂ O ₃ >50, Na ₂ O <0.1m%.

Example 1-2

Take 56.3 grams of kaolin, add 110 ml of deionized water, mix and beat for half an hour, add 2.5 ml of HCl to acidify and beat for half an hour, add pseudo-boehmite containing 13 grams of Al ₂ O ₃ and stir for half an hour, and age at 55±5°C for 2 hours hour, add aluminum sol containing 5.7 grams of Al ₂ O ₃ and stir for 15 minutes, add 25 grams of ground REUSY molecular sieves with unit cell constant of 2.450nm (this molecular sieve is made of high silicon NH ₄ Y molecular sieves through RECl ₃ exchange) obtained, its RE ₂ O ₃ 3.1m%, Na ₂ O 1.0m%), continue beating for half an hour, then transfer to a 15cm×30cm enamel plate, put it in an oven at 110°C for drying, and the dried sample is pulverized 1. Take 20-40 mesh particles and roast at 600°C for 1 hour to obtain sample 1. The composition ratio of the catalyst is shown in Table 1.

The preparation method of sample 2 is the same as that of example 1, and its composition ratio is shown in Table 1.

Comparative example 1

Take 56.3 grams of kaolin, add 170 ml of deionized water, mix and beat for half an hour, add 3 ml of hydrochloric acid to acidify for half an hour, add pseudo-boehmite containing 18.7 grams of Al ₂ O ₃ and continue stirring for half an hour, heat up to 55±5°C for aging After 2 hours, add 25 grams of ground molecular sieves identical to Example 1, and continue beating for half an hour. Other preparation steps are the same as in Example 1 to obtain Sample A-1. The composition ratio is shown in Table 1.

Example 3-5

According to the proportion of sample 3 in Table 1, take 52.5 grams of kaolin, add 100 milliliters of deionized water, mix and _beat for 0.5 hours, add 2 milliliters of hydrochloric acid to acidify for 0.5 hours, add pseudo-boehmite containing 5.3 grams of _Al2O3 and stir Half an hour, aged at 55±5°C for 2 hours, then added aluminum sol containing 12.2 grams of Al ₂ O ₃ and stirred for 15 minutes, then added 30 grams of the ground molecular sieve as in Example 1, and the other preparation steps were the same as in Example 1 to obtain the sample 3. The preparation steps of samples 4 and 5 are the same as in example 3, except that the proportions are different, and the composition proportions are shown in Table 1.

Comparative example 2

According to the proportioning of sample B in table 1, get 52.5 grams of kaolin, join while stirring in the aluminum sol containing 17.5 grams of Al ₂ O ₃ , stir and beating for 1 hour, then add the molecular sieve of the same example 1 and continue beating for 0.5 hour, other The preparation steps are the same as in Example 1 to obtain sample B.

Note: 1. *Total Al ₂ O ₃ m% is calculated based on Al ₂ O ₃ base, the same below.

2. ** Pseudoboehmite: aluminum sol is the weight ratio, the same below.

3. The content of each component of the catalyst in the table refers to the content of calcined radicals calcined at 800°C for 1 hour, the same below.

Example 6

Catalyst samples 1 and 2 of the present invention and sample A-1 of comparative example 1 were subjected to 800°C, 4 hours, 100% hydrothermal treatment, and evaluated on a MAT-II heavy oil micro-reactor device, and the raw oil was 227-478°C Victory Wax Oil, reaction temperature 482°C, agent/oil ratio=3.5 for samples 1 and 2, agent/oil ratio=3 for sample A-1 of comparative example 1, the results are shown in Table 2.

As can be seen from Table 2, the catalyst samples 1 and 2 containing the composite aluminum-based binder of the present invention are compared with the sample A-1 of the single peptized pseudo-boehmite as the binder, and the conversion rate is similar In the case of the former, the coke selectivity of the former is 3.09-3.15%, while that of the latter reaches 4.0%, indicating that the coke produced by the former is significantly less than that of the latter.

Example 7

Catalyst samples 4 and 5 of the present invention and sample B of comparative example 2 were treated at 800°C for 4 hours under 100% water vapor, and evaluated on a MAT-II heavy oil micro-reactor. The raw material oil and reaction temperature were the same as in Example 6. , agent/oil ratio=6, the results are shown in Table 3.

As can be seen from Table 3: the catalyst samples 4 and 5 containing the composite aluminum-based binder of the present invention are compared with the sample B of the binder with a single aluminum sol, under the same situation of agent/oil ratio, gasoline The yield of the former is increased by 2-5 percentage points compared with the latter, and the conversion capacity of heavy oil is increased by 1-3 percentage points.

Example 8-9

According to the ratio of sample 6 in Table 4, 8.8 kg of kaolin was added to 17 kg of deionized water, stirred and beaten for 1 hour, added with 0.7 _kg of industrial grade hydrochloric acid, stirred and acidified for 0.5 hours, and added with pseudo-thin water containing 2.6 kg of _Al2O3 The bauxite was beaten for 0.5 hours, heated to 60±5°C for 1 hour of aging, added aluminum sol containing 0.3 kg of Al ₂ O ₃ and beaten for 0.5 hours, then added 3.3 kg of ground REY molecular sieve, beaten intermittently for 0.5 hours, and spray-dried to shape , after washing and drying, sample 6 was obtained.

The preparation method of sample 7 is the same as that of sample 6, and its composition ratio is shown in Table 4.

Comparative example 3-4

According to the ratio of sample A-2 in Table 4, add 8.8 kg of kaolin to 27 kg of deionized water for beating for 1 hour, add 0.6 kg of industrial grade hydrochloric acid to stir and acidify _for half an hour, add pseudo thin water containing 2.9 kg of _Al2O3 Bauxite, continue beating for 0.5 hours, raise the temperature to 60±5°C, age for 1 hour, add 3.3 kg of the ground molecular sieve as in Example 8, continue beating for 0.5 hours, then spray dry and shape, wash and dry to obtain sample A -2, the preparation method of sample A-3 of comparative example 4 is the same as A-2, and its composition ratio is shown in Table 4.

As can be seen from Table 4, the wear index of the catalyst samples 6 and 7 containing the composite aluminum-based binder of the present invention is 2.0-2.2% hours ^-1 , with a single peptized pseudo-boehmite as the binder The wear indices of the samples A-2 and A-3 are 2.5-3.0% h ^-1 , indicating that the composite aluminum-based binder improves the strength of the catalyst.

Examples 10-11

According to the ratio of sample 8 in Table 5, add 7.9 kg of kaolin to 15 kg of deionized water for beating for 1 hour, add 0.35 kg of industrial grade hydrochloric acid, stir and acidify for 0.5 hour, add pseudo _- boehmite containing 1.3 kg of _Al2O3 Stone, continue beating for 0.5 hours, raise the temperature to 60°C, age for 1 hour, add aluminum sol containing 1.3 kg of Al ₂ O ₃ , continue beating for 0.5 hours, and then add 4.5 kg of ground molecular sieves (the molecular sieves are REY and ZSM-5 The mixture, whose mixing weight ratio is 6:1), was beaten for 0.5 hours, spray-dried to shape, washed and dried, and sample 8 was obtained. The preparation method of sample 9 is the same as that of sample 8, and its composition ratio is shown in Table 5.

Comparative example 5

According to the proportion of _sample A-4 in Table 5, add 7.9 kg of kaolin to 24 kg of deionized water, beat for 1 hour, add 0.6 kg of industrial grade hydrochloric acid for acidification for 0.5 hour, add pseudo thin water containing 2.6 kg of _Al2O3 Continue to beat the alumina stone for 0.5 hours, raise the temperature to 60°C, age for 1 hour, add 4.5 kg of the ground molecular sieve of the same example 10 and beat for 0.5 hours, spray dry and shape, wash and dry to obtain sample A-4.

As can be seen from Table 5: the wear index of the catalyst samples 8 and 9 containing composite aluminum-based binders of the present invention is 1.8-2.2% ^hours However, the abrasion index of the sample A-4 of the catalyst reached 4.0% h ^-1 , indicating that the catalyst of the present invention has better abrasion resistance than the catalyst using a single peptized pseudo-boehmite as a binder.

Claims (9)

1, a kind of catalytic cracking catalyst is characterized in that this catalyzer is that composite aluminum base binding agent by the clay of 20-80m%, 5-40m% is (with Al ₂O ₃Burn base for calculating benchmark), 0-5m% is selected from the oxide compound of Sn, Ti, Mg, Zr, P, Mn, Cr and 5-40m% and is selected from faujusite that lattice constant is 2.432-2.472nm, ZSM-5 zeolite, β zeolite and composition thereof and forms.

2,, it is characterized in that this catalyzer contains the clay of 30-70m% according to the said catalyzer of claim 1.

3,, it is characterized in that this catalyzer contains the composite aluminum base binding agent of 10-30m% according to the said catalyzer of claim 1.

4,, it is characterized in that this catalyzer contains 10-40m% and is selected from faujusite that lattice constant is 2.432-2.472nm, ZSM-5 zeolite, β zeolite and composition thereof according to the said catalyzer of claim 1.

5, according to claim 1 or 3 said catalyzer, it is characterized in that said composite aluminum base binding agent is the mixture of peptization pseudo-boehmite and aluminium colloidal sol, its mixed weight ratio is with Al ₂O ₃The base that burns is 9 for calculating benchmark: 1-1: 9.

6, according to the said catalyzer of claim 5, it is characterized in that said composite aluminum base binding agent is the mixture of peptization pseudo-boehmite and aluminium colloidal sol, its mixed weight ratio is with Al ₂O ₃The base that burns is 7 for calculating benchmark: 3-3: 7.

7,, it is characterized in that said lattice constant is the Y zeolite that the faujusite of 2.432-2.472nm is meant REY, REHY, USY, REUSY and various high silica alumina ratios according to claim 1 or 4 said catalyzer.

8, the said Preparation of catalysts method of claim 1 is characterized in that:

(1) according to the proportion of composing of the said catalyzer of claim 1, clay is mixed making beating 25-35 minute with deionized water, added hcl acidifying 0.5-1 hour, added the pseudo-boehmite stirring to pulp 25-35 minute, wherein the add-on of water is that 20-55m% is as the criterion to keep solid content, and the add-on of hydrochloric acid accounts for Al in the pseudo-boehmite ₂O ₃15～50m% of the base unit weight of burning;

(2) at 50-80 ℃ of aging 0.5-2 hour;

(3) adding aluminium colloidal sol stirred 10-20 minute;

(4) add ground zeolite molecular sieve, continue making beating 25-35 minute;

(5) drying and moulding;

(6) through washing, be drying to obtain product.

9, said according to Claim 8 preparation method is characterized in that (6) money was promptly to get product at 500-700 ℃ of roasting 1-3 hour.