CN114433173B - A kind of method for preparing low apparent bulk density FCC catalyst - Google Patents

Abstract

A method for preparing an FCC catalyst with low apparent bulk density, comprising: forming a first slurry comprising an alumina binder, an active component and water, and spray-drying the first slurry in a spray drying tower, wherein the The drying medium used in the above spray drying contains acid gas, and the concentration of the acid gas in the drying medium is not less than 0.3g/m ³ . The preparation method of the catalyst can reduce the apparent bulk density of the FCC catalyst and make the catalyst have better wear resistance.

Description

A kind of method for preparing low apparent bulk density FCC catalyst

technical field

The invention relates to a method for preparing an FCC catalyst with low apparent bulk density.

Background technique

Fluid Catalytic Cracking (FCC) is an important crude oil secondary processing technology, which uses a fluidized bed reactor and uses microspherical catalytic cracking catalysts or catalytic cracking additives. In order to ensure that the catalyst has good fluidization performance, it needs to have a certain apparent bulk density and also have good anti-wear performance.

At present, catalytic cracking catalysts and additives are mainly semi-synthetic catalysts. The preparation process of the catalyst includes mixing the binder, active components and optional clay in a certain proportion to form a slurry, followed by spray drying, optional roasting, washing, drying and other steps. Among them, commonly used binders include aluminum binders such as alumina sol and/or pseudo-boehmite, but the prepared catalyst often has the problem of relatively high apparent bulk density.

Increasing the pore volume of the catalyst can reduce the apparent bulk density of the catalyst.

CN1831090A reports that polymer particles of 5-1500nm are introduced during the preparation of the catalyst, and the polymer particles are removed after molding to form mesopores. But polymers are expensive, and their incineration poses environmental concerns.

In CN1388214A, by adding a certain amount of β-alumina trihydrate, the bulk specific gravity (apparent bulk density) and pore volume of the catalyst can be adjusted within a wide range.

CN1854258A provides a mesoporous silicon-aluminum material with a pore volume of 0.5-2.0ml/g and a pore diameter of 8-20nm added during the preparation of a catalytic cracking catalyst. However, when the macroporous material is introduced, the binder will be filled into the pores of the macroporous material, resulting in the loss of macropores, the binder entering the macropores will lose its bonding ability, and the wear resistance of the catalyst will be reduced.

In the existing catalytic cracking catalyst preparation methods, increasing the pore volume often leads to deterioration of the wear resistance of the catalyst.

Contents of the invention

The technical problem to be solved by the present invention is to provide a preparation method for reducing the apparent bulk density of the FCC catalyst.

The invention provides a method for preparing a catalyst that reduces the apparent bulk density of the catalyst, the method comprising:

Form the first slurry comprising alumina binder, active component and water, make the first slurry spray dry in the spray drying tower, wherein, the drying medium used in the spray drying contains acid gas, and the drying The concentration of acid gas in the medium is not lower than 0.3g/m ³ . The acid gas concentration in the drying medium is, for example, 0.3-3 g/m ³ , for example, 0.5-2 or 0.6-1.5 g/m ³ . The volume of the drying medium is calculated by the gas volume under standard conditions.

According to the catalyst preparation method of the present invention, the acid gas is a substance that exists in a gaseous state and dissolves in water to form an acid in the temperature range of spray drying (above the tower temperature and below the tower temperature), and the acid gas Gas such as one or more of HCl, SO ₃ , P ₂ O ₅ , NO ₂ , organic acid, preferably one or more of HCl, SO ₃ , P ₂ O ₅ , NO ₂ , more preferably HCl .

According to the catalyst preparation method of the present invention, the acid gas concentration in the drying medium in the spray drying tower is preferably 0.3-3 g/m ³ .

According to the catalyst preparation method of the present invention, the solid content of the first slurry is preferably 5-35% by weight.

According to the catalyst preparation method of the present invention, an acid is also added to the first slurry to acidify the binder, and the acid is an inorganic acid and/or an organic acid. Preferably, the amount of acid added is the same as that of Al ₂ The molar ratio of pseudo-boehmite in terms of _O3 is 0.05-0.2:1, for example, 0.08-0.16:1. The inorganic acid is, for example, one or more of hydrochloric acid, nitric acid, phosphoric acid and sulfuric acid, preferably hydrochloric acid. The organic acid is, for example, one or more of carboxylic acids with 1-10 carbon atoms in the molecule, preferably one or more of formic acid and acetic acid.

According to the catalyst preparation method of the present invention, based on the dry weight of the first slurry, the first slurry includes 20-60% by weight on a dry basis, such as 20-40% by weight or 25-35% by weight of clay, 10-70% by weight on a dry basis, such as 20-50 or 30-45% by weight of active components, 15-70% by weight, such as 20-50% by weight of alumina binder, the alumina bond The agent is pseudoboehmite and optionally alumina sol, for example alumina sol and pseudoboehmite.

According to the catalyst _preparation method of the present invention, based on the dry basis weight of the first slurry, in the first slurry, the amount of pseudo-boehmite added (or content) in terms of _Al2O3 is 10-50% by weight % such as 15-45% by weight or 20-40% by weight or 20-35% by weight.

According to the catalyst preparation method of the present invention, based on the dry basis weight of the first slurry, in the _first slurry, the _aluminum sol addition amount (or content) is 0-20% by weight, such as 3 -15% by weight.

According to the catalyst preparation method of the present invention, the active components may be commonly used active components of catalytic cracking catalysts, such as molecular sieves. The molecular sieve can be a zeolite molecular sieve or a non-zeolite molecular sieve, and the zeolite molecular sieve is, for example, one or more of Y-type zeolite, ZSM-5 zeolite, and beta zeolite, such as Y-type zeolite or Y-type zeolite and ZSM - A mixture of one or more of 5 zeolite and β zeolite. The Y-type zeolite is, for example, HY zeolite, NH ₄ Y zeolite, rare earth Y zeolite, ultrastable Y zeolite, rare earth ultrastable zeolite Y or a mixture of them.

According to the catalyst preparation method of the present invention, the first slurry may also contain clay, such as kaolin, sepiolite, rectorite, montmorillonite, rectorite, halloysite, silicon One or more of algal earth, saponite, rectorite, sepiolite, attapulgite, hydrotalcite, bentonite, preferably kaolin, sepiolite, rectorite, montmorillonite, retortite, One or more of halloysite, more preferably kaolin.

According to the catalyst preparation method of the present invention, the entering temperature of the spray drying (the temperature of the drying medium entering the spray drying tower) is 300-600°C.

According to the catalyst preparation method of the present invention, the outlet temperature of the spray drying (the temperature of the drying medium leaving the spray drying tower) is 100-220°C.

According to the catalyst preparation method of the present invention, in the spray drying, the inlet temperature of the spray drying tower is preferably 300-380°C, and the outlet temperature of the spray drying tower is preferably 100-150°C.

According to the catalyst preparation method of the present invention, the drying medium (or hot air) contacts the atomized first slurry in the spray drying tower to form a spray drying mixture, which is drawn out of the spray drying tower for separation to obtain catalyst microspheres And gas, said gas is called spray drying tail gas. Said separation can adopt the manner of sedimentation separation and/or cyclone separation, which is well known to those skilled in the art, and will not be repeated in the present invention.

According to the catalyst preparation method of the present invention, the drying medium may include one or more of air, flue gas (abbreviated as flue gas), nitrogen, inert gas, and roasting tail gas.

According to the catalyst preparation method of the present invention, the acid gas is contained in the drying medium, and the acid gas can be contained in the drying medium by adding substances capable of forming acid gas, for example, high-concentration hydrochloric acid and HCl gas can be added. , SO ₃ , NO ₂ , N ₂ O ₅ , organic acid that can be vaporized within the spray drying temperature range, and one or more of roasting tail gas. The acid gas is preferably HCl. In one embodiment, the drying medium contains roasting tail gas and other gases, such as one or more of flue gas, air, and nitrogen. The roasting tail gas can be acid-containing waste gas generated during roasting during the preparation process of catalytic cracking catalyst, flue gas desulfurization aid, flue gas desulphurization aid, etc. After the acid-containing waste gas is separated by a cyclone separator (referred to as cyclone), After separating the solid matter therein, the roasting tail gas is obtained, or the roasting tail gas is mixed with other gases such as flue gas to form a drying medium, wherein acid gas can also be further added so that the acid gas content in the drying medium is greater than 0.3g/m ³ preferably It is 0.3-3g/m ³ .

According to the catalyst preparation method of the present invention, after the roasting tail gas is cyclone separated, the solids carried therein are separated, mixed with the spray-dried drying medium, and then introduced into the spray-drying tower. The use of roasting to generate acid gas can reduce the amount of acid used, and the high-temperature gas generated by roasting can also be used to dry the catalyst and reduce the energy consumption of drying medium heating.

The catalyst preparation method according to the present invention may also include a roasting step. The calcining includes calcining the catalyst microspheres obtained by spray drying. Reference can be made to the roasting method in the production of existing catalytic cracking catalysts. In one embodiment, the calcination temperature of the calcination is preferably 450-800°C, preferably 500-700°C. Preferably, the firing time is 1-6 hours. Preferably, the calcination allows more than 90% of the acid in the catalyst to enter into the calcination atmosphere. The calcination atmosphere may be one or more of air, flue gas, inert gas and nitrogen. The roasting is carried out in a roasting furnace. The gas in the roasting atmosphere is led out of the roasting furnace to form roasting tail gas, and the temperature of the roasting tail gas is preferably 500-700°C.

The catalyst preparation method according to the present invention may also include a washing step, and the washing may refer to the washing method in the prior art, for example, it may be washed with an ammonium salt solution, and there is no special requirement in the present invention.

The spray drying tower, roaster, cyclone (abbreviation of cyclone separator) and tail gas treatment system of the present invention can adopt the spray drying, roaster, cyclone and tail gas in the preparation of existing catalytic cracking catalyst and auxiliary agent. Processing system, less equipment changes.

The present invention provides a spray drying system for the above method, including a spray drying tower, a drying medium supply system, a spray drying tail gas extraction system, and a slurry atomization system, wherein the drying medium supply system also includes an acid gas supply system . Among them, the spray drying tower is used to make the atomized product of the atomization system contact with the drying medium for drying; the drying medium system is used to provide hot drying medium to the spray drying tower; the spray drying tail gas extraction system is used to make the drying medium after spray drying Lead out of the spray drying tower; the slurry atomization system is used to make the liquid material to be dried form droplets and then enter the spray drying tower. The drying medium supply system includes an acid gas supply system for introducing acid gas into the drying medium.

The preparation method of the catalyst provided by the invention can provide the microspherical catalytic cracking catalyst with lower apparent bulk density by acidifying the slurry containing alumina binder in the spray drying process. Preferably, by controlling the solid content and acidification degree of the catalyst slurry before spray drying, controlling the spray drying temperature, and using acid gas to realize secondary acidification of the pseudo-boehmite on the outer layer of the spray droplets, the pseudo-thin pseudo-boehmite in the catalyst microspheres can be realized. Gradient acidification of diaspore, the colloidal particle size distribution from the surface layer to the inside of the microspheres in a gradient from small to large, can reduce the apparent bulk density of the catalyst while ensuring that the catalyst strength does not decrease. Preferably, prolonging the drying time of the mist in the spray drying tower can have a better secondary acidification effect.

The catalyst preparation method provided by the invention is used for the preparation of catalytic cracking catalysts, and the catalyst activity is not affected. The method provided by the invention has low cost and can be realized by adding an acid gas adding device to the existing catalyst production device. In the preferred method, the acid can be recovered by introducing the roasting tail gas into the spray-dried tower, and the consumption of the acid can be reduced, which is easy to realize. The catalyst preparation method provided by the invention can be used in the production of catalytic cracking catalysts and auxiliary agents. The catalyst preparation method provided by the present invention is particularly suitable for the preparation of catalytic cracking catalysts or auxiliary agents containing alumina binders, especially suitable for the preparation of catalysts containing pseudo-boehmite binders, without changing the catalyst In the case of the composition, the apparent bulk density of the catalyst is reduced, and the good wear resistance of the catalyst is maintained.

Description of drawings

Fig. 1 is a process flow diagram of the catalyst preparation method provided by the present invention. in,

1. Blower, 2. Roasting furnace, 3. Cyclone separator, 4. Blower, 5. Hot blast stove, 6. Spray drying tower, 7. Cyclone separator, 8. Induced fan, 9. Recycling fan, 10. Tail gas treatment system.

Detailed ways

According to the catalyst preparation method for reducing the apparent bulk density of the catalyst provided by the present invention, one embodiment includes mixing and beating clay, pseudoboehmite, active components, optional aluminum sol and inorganic acid to form a first slurry , the first slurry is spray-dried and molded, and calcined at a high temperature to obtain catalyst microspheres; wherein, the solid content of the first slurry is preferably 5-35% by weight, and the amount of inorganic acid added is the same as that of pseudo-boehmite calculated as Al ₂ O ₃ The molar ratio of the added amount (acid-aluminum ratio) is preferably 0.05:1-0.2:1; the concentration of inorganic acid in the airflow entering the spray drying tower is 0.3-3g/m ³ , the temperature of the spray drying tower entering the tower is 300-600°C, and the The temperature of the tower is 100-220°C. Preferably, the spray-dried catalyst is calcined, and the atmosphere temperature of the calcined furnace is 500-700°C. Preferably, the calcination enables more than 90% of the inorganic acid in the catalyst to be separated from the catalyst into the calcination tail gas. Preferably, the roasting tail gas is introduced into the cyclone separator, separated from the catalyst, mixed with the spray-drying tower drying medium, and then introduced into the spray-drying tower.

According to the catalyst preparation method for reducing the apparent bulk density of the catalyst described in the present invention, in one embodiment, the molecular sieve, clay, pseudoboehmite and inorganic acid are beaten in the following manner: the molecular sieve is mixed with water to form a slurry, and then added The clay and the pseudo-boehmite are uniformly mixed, and then the inorganic acid is added and mixed uniformly to obtain the first slurry.

According to the catalyst preparation method for reducing the apparent bulk density of the catalyst according to the present invention, in one embodiment, the molecular sieve, aluminum sol, clay, pseudoboehmite and inorganic acid are beaten in the following manner: the molecular sieve is mixed with water to form a slurry , then add alumina sol, clay and pseudo-boehmite and mix uniformly, then add inorganic acid and mix uniformly to obtain the first slurry.

The catalyst preparation method for reducing the apparent bulk density of catalysts described in the present invention can be used to prepare microsphere catalysts, for example, can be used to prepare microsphere-shaped catalytic cracking catalysts or catalytic cracking additives. In one embodiment, the catalyst or additives The average diameter is 60-80 microns, the volume of particles with a diameter of less than 149 microns accounts for more than 90% of the total particle volume, and the volume of particles with a diameter of less than 40 microns accounts for less than 40% of the total particle volume.

Below according to the technological process of accompanying drawing 1, the present invention is further described:

As shown in Figure 1, the natural gas and the air introduced by the blower 4 are burned in the hot blast stove 5 to form hot blast. The air provided by the blower 1 enters the roasting furnace 2, and the acid in the catalyst in the roasting furnace 2 is roasted out and then enters the roasting atmosphere, and the gas in the roasting atmosphere is led out of the roasting furnace to form an acid-containing tail gas, and the carried catalyst is separated by the cyclone separator 3 Finally, after mixing with the hot blast from the hot blast furnace 5, it enters the spray drying tower 6 and contacts the atomized first slurry for drying, and the dried hot blast carries the catalyst into the cyclone separator 7 to separate the catalyst therein, and the partially dried hot blast Reuse the outlet of the hot blast stove 5 by reusing the blower fan 9 . An acid gas delivery pipeline is added to the drying medium delivery pipeline between the hot blast stove 5 and the spray drying tower 6, for introducing the acid gas into the drying medium delivery pipeline. At the same time, the first slurry is atomized through the nozzle, enters the spray drying tower 6, and contacts with the drying medium entering the spray drying tower 6. The surface of the atomized initial droplet is wet, and the acid-containing mixed gas in the tower can gradually contact the surface of the droplet, and the pseudo-boehmite on the surface of the formed initial droplet is acidified twice to improve the pseudo-boehmite on the surface of the droplet. The degree of peptization can realize the gradient acidification of pseudo-boehmite in the catalyst microspheres, so that the particle size of the colloidal particles can be distributed from small to large gradients from the surface to the interior of the microspheres.

In the present invention, the water droplet pore volume, wear index, and apparent bulk density (bulk ratio) are respectively according to (NB/SH/T 0955-2017, NB/SH/T 0964-2017, NB/SH/T 0954-2017 standard method Determination. Light oil micro-reactive activity was evaluated on a small fixed-bed reactor according to NB/SH/T0952-2017.

Example 1

Add 300.4kg of water in the gelling kettle, and then add the SOY-8 molecular sieve (the product produced by Sinopec Catalyst Qilu Branch Company, which is a Y-type molecular sieve containing rare earths, with a concentration of 40% by weight) uniformly dispersed SOY-8 molecular sieve, RE ₂ O _The content is 8.0 % by weight, the same below) slurry 92.5Kg, then add aluminum sol (the product produced by Sinopec Catalyst Qilu Branch, with an alumina content of 21.5% by weight, the same below) 23.3Kg and stir for 10 minutes, then add kaolin 42.9Kg (product of Suzhou Kaolin Co., Ltd. , burning 23% by weight, the same below), beating for 90 minutes, adding pseudo-boehmite 41Kg (the product of Shanxi Branch of Aluminum Corporation of China, burning 39% by weight, the same below, referred to as bauxite), stirring for 30 Minutes, add concentration and be 3.75Kg of industrial hydrochloric acid 3.75Kg (acid-aluminum ratio of 36% by weight) acidify 90 minutes and form the first slurry, then use the pressure type spray drier to be 370 ℃ at the spray drying tower inlet temperature, the spray drying tower outlet temperature is 110 The catalyst microspheres are obtained by spray drying at ℃, wherein the drying medium of the spray drying tower is flue gas, the HCl concentration is 0.72g/m ³ , the induced air volume is 3000m ³ /h, and the spray flow rate is 14kg/min. The spray sample (i.e. the catalyst microspheres obtained by spray drying) was roasted, washed and dried to obtain the catalyst CAT-1, wherein the atmosphere temperature in the roasting furnace was 550°C, and the roasting time was 2h; the washing (the same below) was performed at a concentration of 1 The weight % ammonium sulfate solution was washed twice, and for each wash, the weight ratio of the ammonium sulfate solution to the catalyst was 10:1, the washing temperature was 60° C., and the washing time was 20 minutes, and then filtered.

The formulations of the examples and comparative examples in Table 1 are the weight percentages on a dry basis.

Example Molecular sieve Kaolin Aluminum stone Aluminum sol Solid content of the first slurry, wt% Acid-aluminum ratio Example 1 37 33 25 5 20 0.15 Example 2 37 33 25 5 35 0.15 Example 3 35 25 37 3 20 0.2 Example 4 42 25 twenty two 11 35 0.15 Comparative example 1 37 33 25 5 20 0.15 Comparative example 2 37 33 25 5 20 0.2 Comparative example 3 35 25 37 3 20 0.2 Comparative example 4 35 25 37 3 20 0.3

In Table 1, the acid-aluminum ratio is the molar ratio of the HCl added in the process of forming the first slurry to the pseudo-boehmite (referred to as bauxite) calculated as alumina.

Table 2 embodiment and comparative example preparation process condition

Table 3 embodiment and comparative example performance evaluation

Wear index%/h Pore volumeml/g Apparent bulk density g/ml light oil slightly reactive Example 1 1.2 0.40 0.72 68 Example 2 1.1 0.39 0.73 68 Example 3 1.2 0.42 0.71 69 Example 4 2 0.41 0.72 70 Comparative example 1 2.5 0.41 0.71 68 Comparative example 2 1.2 0.36 0.80 64 Comparative example 3 2.8 0.43 0.70 69 Comparative example 4 1.2 0.37 0.79 63

Example 2

The catalyst was prepared with reference to Example 1, the difference being the solid content of the first slurry and the concentration of HCl in the drying medium.

Example 3

The catalyst is prepared with reference to Example 1. The difference is that the catalyst formula of Example 3 is as shown in Table 1, and the concentration of HCl in the drying medium, the inlet temperature and the tower outlet temperature of spray drying are as shown in Table 2, and the rest of the preparation conditions are the same as in Example 1.

Example 4

The catalytic cracking catalyst was prepared with reference to the method of Example 1, and the formulation of the catalyst was shown in Table 1, wherein. The operating conditions are shown in Table 2, and the concentration of HCl in the drying medium, the inlet temperature and the outlet temperature of the spray drying are shown in Table 2.

Comparative example 1

Referring to the method of Example 1, the difference is that HCl is not introduced into the drying medium of spray drying, and the acid-aluminum ratio is the same as that of Example 1. It can be seen that the pore volume and apparent bulk density of the catalyst are close to those of Example 1, but its wear index is higher than that of Example 1, and its anti-wear performance is poor.

Comparative example 2

Referring to the method of Example 1, the difference is that no HCl is introduced into the drying medium during the spray drying process, and the degree of acidification of bauxite in the gel forming process (the process of forming the first slurry) is increased (ie, the acid-aluminum ratio is increased). As can be seen from Table 3, compared with Comparative Example 1, the catalyst apparent bulk density is high, and the wear index reduces, and embodiment 1 is equivalent, and pore volume declines, and catalyst activity is lower,

Comparative example 3

According to the method of Example 3, no secondary acidification technology is used, that is, no hydrogen chloride is introduced in the drying medium, the acid-aluminum ratio of the bauxite acidification in the gelling process is the same as that of Example 3, and the catalyst pore volume and apparent bulk density are the same as those of Example 3. close, but the wear resistance of the catalyst is poor.

Comparative example 4

Catalyst is prepared according to the method of embodiment 3, does not adopt secondary acidification (do not introduce HCl in the spray drying), improves the degree of acidification of bauxite in the process of gelling, that is, increases the acid-aluminum ratio, and its strength is better, but the apparent bulk density of catalyst ( Also known as stack ratio) is high, the pore volume is small, and the catalyst activity is low.

For Examples 1-4 and Comparative Examples 1-4, see Table 1 for the formula for preparing the catalyst, see Table 2 for the spray drying process conditions and calcination temperature, and see Table 3 for the properties of the obtained catalyst.

It can be seen from Tables 1-3 that the method of the present invention can reduce the apparent bulk density of the catalyst, increase the pore volume of the catalyst while maintaining good catalyst strength, and surprisingly also improve the catalyst activity.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details in the above-mentioned embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications are all Belong to the protection scope of the present invention.

The various specific technical features described in the above specific implementation manners may be combined in any suitable manner if there is no contradiction.

Any combination of various implementations of the present invention can also be made, as long as they do not violate the idea of the present invention, they should also be regarded as the disclosed content of the present invention.

Claims (14)

1. A method of preparing a low apparent bulk catalyst comprising:

forming a first slurry comprising an alumina binder, clay, molecular sieve and water, and spray-drying the first slurry in a spray-drying tower, wherein a drying medium used for the spray-drying contains an acid gas, and the concentration of the acid gas in the drying medium is not less than 0.3g/m ³ Wherein the volume of the drying medium is based on the gas volume under standard conditions; the alumina binder comprises pseudo-boehmite and optional alumina sol, wherein acid is added into the first slurry, the acid is inorganic acid and/or organic acid, and the addition amount of the acid is equal to that of the alumina sol ₂ O ₃ The molar ratio of the pseudo-boehmite is 0.05-0.2.

2. The method of claim 1, wherein the pseudoboehmite is present in the first slurry in an amount of Al based on the dry weight of the first slurry ₂ O ₃ 10-50 wt% of aluminum sol with Al content ₂ O ₃ 0-20 wt%.

3. The method according to claim 1 or 2, characterized in that: the first slurry comprises, based on a first slurry dry basis: 20-60 wt% clay on dry basis, 10-70 wt% molecular sieve on dry basis and Al ₂ O ₃ 15-70 wt% of an alumina binder.

4. The method of claim 1, wherein the first slurry has a solids content of 5 to 35 wt%.

5. The method of claim 1, wherein the acid is added to the first slurry in an amount equivalent to that of Al ₂ O ₃ The calculated molar ratio of the pseudo-boehmite is 0.08-0.16:1, a step of; the organic acid is one or more of carboxylic acids with 1-10 carbon atoms in the molecule.

6. The method according to claim 1, wherein the organic acid is one or more of formic acid and acetic acid; the inorganic acid is one or more of hydrochloric acid, nitric acid, phosphoric acid and sulfuric acid.

7. The method of claim 1, wherein the first slurry is prepared by: mixing a molecular sieve with water to form slurry, adding kaolin and pseudo-boehmite, uniformly mixing, and adding inorganic acid, and uniformly mixing to obtain first slurry; or mixing the molecular sieve with water to form slurry, adding the aluminum sol, the kaolin and the pseudo-boehmite, uniformly mixing, and adding the inorganic acid, and uniformly mixing to obtain first slurry.

8. The method according to claim 1, wherein the concentration of the acid gas in the drying medium is 0.3-3g/m ³ The method comprises the steps of carrying out a first treatment on the surface of the The acid gas is HCl or SO ₃ 、P ₂ O ₅ 、NO ₂ One or more of organic acids.

9. The method of claim 1, wherein the spray-dried feed tower temperature is 300-600 ℃; the outlet temperature of the spray drying is 100-220 ℃.

10. The method of claim 9, wherein the spray drying is performed at a spray drying tower inlet temperature of 300-380 ℃ and a spray drying tower outlet temperature of 100-150 ℃.

11. The method according to claim 1, wherein the spray-dried catalyst is further calcined, and the temperature of the atmosphere in the calcining furnace is controlled to be 500-700 ℃.

12. The method according to claim 1 or 11, wherein the drying medium comprises roasting tail gas, and the roasting tail gas is catalytic cracking catalyst or flue gas desulfurization auxiliary agent or gas obtained by separating solid substances from acid-containing waste gas generated during roasting of flue gas denitration auxiliary agent.

13. The method of claim 1, wherein the clay is one or more of kaolin, sepiolite, rectorite, montmorillonite, rectorite, halloysite; the molecular sieve is one or more of Y-type zeolite, ZSM-5 zeolite and beta zeolite.

14. The method of claim 13, wherein the Y-zeolite is HY, NH ₄ Y, rare earth Y, ultrastable Y and one or more of rare earth ultrastable Y.