Preparation method of catalytic cracking catalyst
By preparing a catalytic cracking catalyst support from bauxite and combining it with acid treatment and modified materials, the problems of insufficient catalyst pore volume and specific surface area were solved, resulting in better heavy oil conversion and coke control.
Patent Information
- Application Number
- CN202410847964.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-27
- Publication Date
- 2025-12-30
AI Technical Summary
Existing catalytic cracking catalysts have insufficient pore volume and specific surface area, making it difficult to meet the requirements of heavy oil conversion and coking control, especially in the process of heavy oil processing.
A catalyst support for catalytic cracking was prepared using bauxite. After acid treatment and the addition of ammonium borate as a modifier, the catalyst was combined with kaolin, boehmite, rare earth solution and USY molecular sieve, and then spray-dried and calcined to form a catalyst with high pore volume and specific surface area.
It significantly increased the pore volume and specific surface area of the catalyst, enhanced the heavy oil cracking capacity and coke selectivity, improved the conversion rate and reduced the coke yield.
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Figure CN121222471A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of catalyst preparation, and relates to a preparation method of a catalytic cracking catalyst. BACKGROUND
[0002] Catalytic cracking is still one of the main means for the secondary processing conversion of heavy oil in the petroleum chemical industry. With the reduction of global oil reserves and the development of processing technology, catalytic cracking has developed from processing only wax oil to processing more heavy oil such as residual oil. In China, the heavy oil catalytic cracking device generally blends 5% to 20% of residual oil, and some devices even process full residual oil.
[0003] The catalytic cracking catalyst plays a crucial role in the catalytic cracking reaction. The performance of the catalyst determines the conversion rate of the device and the selectivity of the product. The catalytic cracking catalyst is mainly composed of a matrix and active components and a binder. The matrix component not only serves as a carrier for the active components, but also affects the pre-cracking of heavy oil molecules and the diffusion of oil and gas molecules. Under the condition of increasingly poor and heavy feedstock oil, higher requirements are put forward for the pore distribution, specific surface area and acidity of the carrier material of the catalytic cracking catalyst, so that the catalyst has better heavy oil conversion capacity and reduces coke formation.
[0004] The traditional catalytic cracking catalyst carrier is mainly kaolin. The pore volume of kaolin is generally about 0.1 ml / g, and the specific surface area is generally only 10-30 m 2 / g. Another carrier material added in the catalyst is acidified small-pore pseudo-boehmite. The pore volume of pseudo-boehmite is above 0.3 ml / g, and the specific surface area is above 300 m 2 / g. However, the pore size distribution of pseudo-boehmite is relatively concentrated, and is concentrated at about 3.4 nm. In addition, the pore volume and specific surface area will decrease after acid treatment during the preparation of the catalyst. The pore volume of the traditional catalytic cracking catalyst is about 0.3-0.4 ml / g, and the specific surface area is about 220-280 m 2 / g. The specific surface area of the matrix is about 80-100 m 2 / g. In recent years, the supply of pseudo-boehmite in China is insufficient, the content of pseudo-boehmite in the catalytic cracking catalyst has slightly decreased, and the specific surface area of the matrix has a decreasing trend. The large-pore, large-specific-surface-area carrier material of the existing catalytic cracking catalyst is mainly modified kaolin. The modified kaolin generally needs to be calcined into metakaolin at above 700℃, and then acid treated to increase the pore volume and specific surface area. The pore volume of the modified kaolin is generally only about 0.15 ml / g, and the specific surface area is also only about 150 m 2 / g at most. SUMMARY
[0005] The application aims to provide a preparation method of a catalytic cracking catalyst.
[0006] The technical scheme adopted by the application is a preparation method of a catalytic cracking catalyst, and the specific steps are as follows:
[0007] Step 1: preparing a catalytic cracking catalyst carrier by using bauxite;
[0008] Step 2: adding kaolin, pseudo-boehmite and a rare earth solution into the catalytic cracking catalyst carrier obtained in step 1 in sequence to obtain a first mixed slurry, adjusting the pH value and temperature of the first mixed slurry, and performing aging to obtain a second mixed slurry;
[0009] Step 3: adding aluminum sol and USY molecular sieve into the second mixed slurry in sequence and stirring to obtain a third mixed slurry;
[0010] Step 4: spray drying and shaping the third mixed slurry to obtain a catalytic cracking catalyst crude product, and performing calcination, water washing and drying on the catalytic cracking catalyst crude product to obtain a catalytic cracking catalyst.
[0011] The application also has the following characteristics:
[0012] Step 1 is specifically as follows:
[0013] Step 1.1: grinding the bauxite to below 60 mesh to obtain bauxite powder, calcining the bauxite powder in a muffle furnace and cooling to room temperature to obtain activated bauxite powder;
[0014] Step 1.2: adding the activated bauxite powder into a solution containing hydrochloric acid and phosphoric acid, adding a modification substance, and stirring uniformly to obtain a slurry;
[0015] Step 1.3: heating and constant-temperature reacting the slurry in a sealed container to obtain a catalytic cracking catalyst carrier.
[0016] In step 1.1, the weight content of aluminum oxide in the bauxite is 55%-70%, the weight content of silicon oxide is 25%-40%, the weight content of sodium oxide is less than 0.8%, the weight content of potassium oxide is less than 0.8%, and the weight content of other impurities is less than 5%.
[0017] In step 1.1, the temperature for calcining the bauxite powder in the muffle furnace is 200-350 DEG C, and the calcination time is 10-30 min.
[0018] In step 1.2, the mass ratio of hydrochloric acid to activated bauxite powder is 0.35-0.45:1, the mass ratio of phosphoric acid to activated bauxite powder is 0.08-0.2:1, the modifying material is ammonium borate, the mass ratio of ammonium borate to activated bauxite powder is 0.08-0.15:1, the stirring time is 5 min-15 min, and the solid content of the slurry is 35%-50%.
[0019] In step 1.3, the sealed container is a stainless steel reactor with an acid and alkali resistant lining. The slurry heating rate is 5℃ / min-15℃ / min, the isothermal reaction temperature is 120℃-150℃, and the isothermal reaction time is 30min-120min.
[0020] The dry weight ratio of the catalytic cracking catalyst support to kaolin is 1:0.6-9, the dry weight ratio of the catalytic cracking catalyst support to boehmite is 1:0.2-3, the dry weight ratio of the catalytic cracking catalyst support to rare earth solution is 1:0.01-0.3, the dry weight ratio of the catalytic cracking catalyst support to alumina sol is 1:0.15-3, and the dry weight ratio of the catalytic cracking catalyst support to USY molecular sieve is 1:0.6-8.
[0021] In step 2, the solid content of the catalytic cracking catalyst support is 25%-40%, the pH of the first mixed slurry is adjusted to 2.5-4.0, the aging temperature is 30℃-65℃, and the aging time is 1h-2h.
[0022] In step 3, after adding aluminum sol and USY molecular sieve to the second mixed slurry in sequence, the stirring time is 0.5h-5h.
[0023] In step 4, the crude product of the catalytic cracking catalyst is calcined at a temperature of 450℃-500℃ for 0.5h-1h. During water washing, the mass ratio of water to crude product of the catalytic cracking catalyst is 5-8:1. The drying temperature is 60℃-150℃ and the drying time is 2h-4h.
[0024] The beneficial effects of this invention are:
[0025] (1) In the preparation method of the catalytic cracking catalyst of the present invention, bauxite is first used to prepare a support. The activation temperature is relatively low, and acid treatment significantly increases the pore volume and specific surface area of the support. The catalytic cracking catalyst prepared by the present invention has a pore volume higher than 0.55 ml / g and a support specific surface area higher than 350 m² / g. 2 / g, and has a stepped pore distribution structure in the range of 2 to 100 nm;
[0026] (2) The method for preparing the catalytic cracking catalyst of the present invention adds boric acid modified material when preparing the support. The prepared support is rich in Brønsted acid. The catalytic cracking catalyst prepared by the support has a stronger heavy oil cracking ability and better coke selectivity. Attached Figure Description
[0027] Figure 1 This is a comparison diagram of the pore distribution of the catalytic cracking catalyst support prepared in Example 1 with that of boehmite and kaolin.
[0028] Figure 2 The image shows an infrared acidity comparison between the catalytic cracking catalyst support prepared in Example 1 and boehmite. Detailed Implementation
[0029] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0030] The preparation method of the catalytic cracking catalyst of the present invention is carried out according to the following steps:
[0031] Step 1: Prepare a catalytic cracking catalyst support using bauxite;
[0032] Step 1.1: Grind bauxite to below 60 mesh to obtain bauxite powder. Roast the bauxite powder in a muffle furnace at a temperature of 200℃-350℃ for 10min-30min. Then cool it to room temperature to obtain activated bauxite powder.
[0033] The bauxite contains 55%-70% alumina by weight, 25%-40% silica by weight, less than 0.8% sodium oxide by weight, less than 0.8% potassium oxide by weight, and less than 5% other impurities by weight.
[0034] Step 1.2: Add the activated bauxite powder to a solution containing hydrochloric acid and phosphoric acid, wherein the mass ratio of hydrochloric acid to activated bauxite powder is 0.35-0.45:1, and the mass ratio of phosphoric acid to activated bauxite powder is 0.08-0.2:1. Then add the modified substance ammonium borate, wherein the mass ratio of ammonium borate to activated bauxite powder is 0.08-0.15:1. Stir for 5-15 minutes to obtain a slurry with a solid content of 35%-50%.
[0035] Step 1.3: The slurry is heated and kept at a constant temperature in a stainless steel reactor with an acid and alkali resistant lining. The heating rate is 5℃ / min-15℃ / min, the constant temperature reaction temperature is 120℃-150℃, and the constant temperature reaction time is 30min-120min, to obtain the catalytic cracking catalyst support.
[0036] Step 2: Kaolin, boehmite, and rare earth solution are added sequentially to the catalytic cracking catalyst support obtained in Step 1 to obtain the first mixed slurry. The solid content of the catalytic cracking catalyst support is 25%-40%. The pH value of the first mixed slurry is adjusted to 2.5-4.0, the temperature is adjusted to 30℃-65℃, and it is aged for 1-2 hours to obtain the second mixed slurry.
[0037] Step 3: Add aluminum sol and USY molecular sieve to the second mixed slurry in sequence, and stir for 0.5h-5h to obtain the third mixed slurry;
[0038] The dry weight ratio of the catalytic cracking catalyst support to kaolin is 1:0.6-9; the dry weight ratio of the catalytic cracking catalyst support to boehmite is 1:0.2-3; the dry weight ratio of the catalytic cracking catalyst support to rare earth solution is 1:0.01-0.3; the dry weight ratio of the catalytic cracking catalyst support to alumina sol is 1:0.15-3; and the dry weight ratio of the catalytic cracking catalyst support to USY molecular sieve is 1:0.6-8.
[0039] Step 4: Spray dry the third mixed slurry to obtain the crude product of catalytic cracking catalyst. Calcinate the crude product of catalytic cracking catalyst at a temperature of 450℃-500℃ for 0.5h-1h. Then wash with water and dry. During washing, the mass ratio of water to crude product of catalytic cracking catalyst is 5-8:1. Dry at a temperature of 60℃-150℃ for 2h-4h to obtain the final catalytic cracking catalyst.
[0040] The main components of bauxite used in this invention are silicon dioxide and aluminum oxide, with low content of other impurities. Compared with kaolin, bauxite has a lower roasting and activation temperature. Acid treatment significantly increases the specific surface area and pore volume of bauxite. The combined action of acid and boric acid as a modifier causes bauxite to form a large amount of Brønsted acid, which makes the catalytic cracking catalyst prepared by this invention have stronger heavy oil cracking ability and better coke selectivity.
[0041] Example 1
[0042] The preparation method of catalytic cracking catalyst is carried out according to the following steps:
[0043] Step 1: Prepare a catalytic cracking catalyst support using bauxite;
[0044] Step 1.1: Grind 500g of bauxite to below 60 mesh to obtain bauxite powder. Roast the bauxite powder in a muffle furnace and cool it to room temperature. The roasting temperature is 350℃ and the roasting time is 15min to obtain activated bauxite powder.
[0045] Step 1.2: In a lined stainless steel reactor, add activated bauxite powder, 510g of 37% concentrated hydrochloric acid, 118g of 85% concentrated phosphoric acid, and 50g of ammonium borate in sequence, and stir for 10 minutes to obtain a slurry.
[0046] Step 1.3: Seal the reactor and raise the temperature to 120°C at a heating rate of 5°C / min. React at this temperature for 60 min to obtain the catalytic cracking catalyst support.
[0047] Step 2: Kaolin, boehmite, and rare earth solution are added sequentially to the catalytic cracking catalyst support obtained in Step 1 to obtain the first mixed slurry, wherein the solid content of the catalytic cracking catalyst support is 35%. The pH value of the first mixed slurry is adjusted to 3.0, the temperature is adjusted to 65℃, and it is aged for 1 hour to obtain the second mixed slurry.
[0048] Step 3: Add aluminum sol and USY molecular sieve to the second mixed slurry in sequence and stir for 1 hour to obtain the third mixed slurry;
[0049] The dry basis mass ratio of the catalytic cracking catalyst support to kaolin, pseudoboehmite, rare earth solution, alumina sol, and USY molecular sieve is 5.5%:42.5%:10%:2%:5%:35%.
[0050] Step 4: Spray dry the third mixed slurry to obtain the crude product of catalytic cracking catalyst. Calcinate the crude product of catalytic cracking catalyst at 450℃ for 40 min. Then wash with water and dry. The mass ratio of water to crude product of catalytic cracking catalyst during washing is 8:1. Dry at 100℃ for 4 h to obtain the catalytic cracking catalyst.
[0051] Example 2
[0052] The preparation method of catalytic cracking catalyst is carried out according to the following steps:
[0053] Step 1: Prepare a catalytic cracking catalyst support using bauxite;
[0054] Step 1.1: Grind 500g of bauxite to below 60 mesh to obtain bauxite powder. Roast the bauxite powder in a muffle furnace and cool it to room temperature. The roasting temperature is 200℃ and the roasting time is 30min to obtain activated bauxite powder.
[0055] Step 1.2: In a lined stainless steel reactor, add activated bauxite powder, 470g of 37% concentrated hydrochloric acid, 47g of 85% concentrated phosphoric acid, and 40g of ammonium borate in sequence, stir for 5 minutes to obtain a slurry.
[0056] Step 1.3: Seal the reactor and raise the temperature to 130°C at a heating rate of 15°C / min. React at this temperature for 120 min to obtain the catalytic cracking catalyst support.
[0057] Step 2: Kaolin, boehmite, and rare earth solution are added sequentially to the catalytic cracking catalyst support obtained in Step 1 to obtain the first mixed slurry, wherein the solid content of the catalytic cracking catalyst support is 40%. The pH value of the first mixed slurry is adjusted to 2.5, the temperature is adjusted to 45℃, and it is aged for 1.5h to obtain the second mixed slurry.
[0058] Step 3: Add aluminum sol and USY molecular sieve to the second mixed slurry in sequence and stir for 3 hours to obtain the third mixed slurry;
[0059] The dry basis mass ratio of the catalytic cracking catalyst support to kaolin, pseudoboehmite, rare earth solution, alumina sol, and USY molecular sieve is 25%:30%:6.5%:1.5%:12%:25%.
[0060] Step 4: Spray dry the third mixed slurry to obtain the crude product of catalytic cracking catalyst. Calcinate the crude product of catalytic cracking catalyst at 500℃ for 30 minutes. Then wash with water and dry. The mass ratio of water to crude product of catalytic cracking catalyst during washing is 5:1. Dry at 150℃ for 2 hours to obtain the catalytic cracking catalyst.
[0061] Example 3
[0062] The preparation method of catalytic cracking catalyst is carried out according to the following steps:
[0063] Step 1: Prepare a catalytic cracking catalyst support using bauxite;
[0064] Step 1.1: Grind 500g of bauxite to below 60 mesh to obtain bauxite powder. Roast the bauxite powder in a muffle furnace and cool it to room temperature. The roasting temperature is 250℃ and the roasting time is 10min to obtain activated bauxite powder.
[0065] Step 1.2: In a lined stainless steel reactor, add activated bauxite powder, 608g of 37% concentrated hydrochloric acid, 106g of 85% concentrated phosphoric acid, and 75g of ammonium borate in sequence, and stir for 10 minutes to obtain a slurry.
[0066] Step 1.3: Seal the reactor and raise the temperature to 150°C at a heating rate of 10°C / min. React at this temperature for 30 min to obtain the catalytic cracking catalyst support.
[0067] Step 2: Kaolin, boehmite, and rare earth solution are added sequentially to the catalytic cracking catalyst support obtained in Step 1 to obtain the first mixed slurry, wherein the solid content of the catalytic cracking catalyst support is 32%. The pH value of the first mixed slurry is adjusted to 4.0, the temperature is adjusted to 35℃, and it is aged for 2 hours to obtain the second mixed slurry.
[0068] Step 3: Add aluminum sol and USY molecular sieve to the second mixed slurry in sequence and stir for 2 hours to obtain the third mixed slurry;
[0069] The dry-basis mass ratio of the catalyst support for catalytic cracking to kaolin, pseudoboehmite, rare earth solution, alumina sol, and USY molecular sieve is 28%:23.5%:10%:0.5%:8%:30%.
[0070] Step 4: Spray dry the third mixed slurry to obtain the crude product of catalytic cracking catalyst. Calcinate the crude product of catalytic cracking catalyst at a temperature of 460℃ for 1 hour. Then wash with water and dry. The mass ratio of water to crude product of catalytic cracking catalyst during washing is 6:1. Dry at a temperature of 80℃ for 4 hours to obtain the final catalytic cracking catalyst.
[0071] Example 4
[0072] The preparation method of catalytic cracking catalyst is carried out according to the following steps:
[0073] Step 1: Prepare a catalytic cracking catalyst support using bauxite;
[0074] Step 1.1: Grind 500g of bauxite to below 60 mesh to obtain bauxite powder. Roast the bauxite powder in a muffle furnace and cool it to room temperature. The roasting temperature is 200℃ and the roasting time is 30min to obtain activated bauxite powder.
[0075] Step 1.2: In a lined stainless steel reactor, add activated bauxite powder, 470g of 37% concentrated hydrochloric acid, 47g of 85% concentrated phosphoric acid, and 40g of ammonium borate in sequence, stir for 5 minutes to obtain a slurry.
[0076] Step 1.3: Seal the reactor and raise the temperature to 130°C at a heating rate of 15°C / min. React at this temperature for 120 min to obtain the catalytic cracking catalyst support.
[0077] Step 2: Kaolin, boehmite, and rare earth solution are added sequentially to the catalytic cracking catalyst support obtained in Step 1 to obtain the first mixed slurry, wherein the solid content of the catalytic cracking catalyst support is 25%. The pH value of the first mixed slurry is adjusted to 3.5, the temperature is adjusted to 55℃, and it is aged for 1.5h to obtain the second mixed slurry.
[0078] Step 3: Add aluminum sol and USY molecular sieve to the second mixed slurry in sequence and stir for 5 hours to obtain the third mixed slurry;
[0079] The dry basis mass ratio of the catalytic cracking catalyst support to kaolin, pseudoboehmite, rare earth solution, alumina sol, and USY molecular sieve is 10%:26.5%:15%:3%:5.5%:40%.
[0080] Step 4: Spray dry the third mixed slurry to obtain the crude product of catalytic cracking catalyst. Calcinate the crude product of catalytic cracking catalyst at a temperature of 480℃ for 30 minutes. Then wash with water and dry. The mass ratio of water to crude product of catalytic cracking catalyst during washing is 8:1. Dry at a temperature of 60℃ for 4 hours to obtain the catalytic cracking catalyst.
[0081] Example 5
[0082] The preparation method of catalytic cracking catalyst is carried out according to the following steps:
[0083] Step 1: Prepare a catalytic cracking catalyst support using bauxite;
[0084] Step 1.1: Grind 500g of bauxite to below 60 mesh to obtain bauxite powder. Roast the bauxite powder in a muffle furnace and cool it to room temperature. The roasting temperature is 350℃ and the roasting time is 15min to obtain activated bauxite powder.
[0085] Step 1.2: In a lined stainless steel reactor, add activated bauxite powder, 510g of 37% concentrated hydrochloric acid, 118g of 85% concentrated phosphoric acid, and 50g of ammonium borate in sequence, and stir for 10 minutes to obtain a slurry.
[0086] Step 1.3: Seal the reactor and raise the temperature to 120°C at a heating rate of 5°C / min. React at this temperature for 60 min to obtain the catalytic cracking catalyst support.
[0087] Step 2: Kaolin, boehmite, and rare earth solution are added sequentially to the catalytic cracking catalyst support obtained in Step 1 to obtain the first mixed slurry, wherein the solid content of the catalytic cracking catalyst support is 34%. The pH value of the first mixed slurry is adjusted to 2.5, the temperature is adjusted to 40℃, and it is aged for 1 hour to obtain the second mixed slurry.
[0088] Step 3: Add aluminum sol and USY molecular sieve to the second mixed slurry in sequence and stir for 0.5 h to obtain the third mixed slurry;
[0089] The dry basis mass ratio of the catalyst support for catalytic cracking to kaolin, pseudoboehmite, rare earth solution, alumina sol, and USY molecular sieve is 30%:22.2%:12%:0.8%:15%:20%.
[0090] Step 4: Spray dry the third mixed slurry to obtain the crude product of catalytic cracking catalyst. Calcinate the crude product of catalytic cracking catalyst at 500℃ for 40 min. Then wash with water and dry. The mass ratio of water to crude product of catalytic cracking catalyst during washing is 7:1. Dry at 120℃ for 3 h to obtain the catalytic cracking catalyst.
[0091] Comparative Example 1
[0092] Water, kaolin, boehmite, and rare earth solution were sequentially added to a stirred reactor. The pH was adjusted to 3.0, the temperature was controlled at 65℃, and the mixture was stirred for 1 hour. Aluminum sol and USY molecular sieve were then added to the reactor, and stirring was continued for another hour. The mixture was spray-dried and calcined at 450℃ for 40 minutes. After washing with 8 times the amount of water, the mixture was dried in an oven at 100℃ for 4 hours to obtain the catalyst sample. The dry basis mass ratio of kaolin to boehmite, rare earth solution, aluminum sol, and USY molecular sieve was 48%:10%:2%:5%:35%, and the final slurry solid content was 35%.
[0093] Comparative Example 2
[0094] Water, kaolin, boehmite, and rare earth solution were sequentially added to a stirred reactor. The pH was adjusted to 2.5, the temperature was controlled at 45℃, and the mixture was stirred for 1.5 hours. Aluminum sol and USY molecular sieve were then added to the reactor, and stirring continued for 3 hours. The mixture was spray-dried to form a catalyst sample, calcined at 500℃ for 30 minutes, washed with 5 times its volume of water, and dried in an oven at 150℃ for 2 hours to obtain the catalyst sample. The dry basis mass ratio of kaolin to boehmite, rare earth solution, aluminum sol, and USY molecular sieve was 55%:6.5%:1.5%:12%:25%, and the final slurry solid content was 40%.
[0095] Comparative Example 3
[0096] Water, kaolin, boehmite, and rare earth solution were sequentially added to a stirred reactor. The pH was adjusted to 4.0, the temperature was controlled at 35℃, and the mixture was stirred for 2 hours. Aluminum sol and USY molecular sieve were then added to the reactor, and stirring continued for another 2 hours. The mixture was spray-dried to form a catalyst, calcined at 460℃ for 60 minutes, washed with 6 times its volume of water, and dried in an oven at 80℃ for 4 hours to obtain the catalyst sample. The dry basis mass ratio of kaolin to boehmite, rare earth solution, aluminum sol, and USY molecular sieve was 51.5%:10%:0.5%:8%:30%, and the final slurry solid content was 32%.
[0097] Comparative Example 4
[0098] Water, kaolin, boehmite, and rare earth solution were sequentially added to a stirred reactor. The pH was adjusted to 3.5, the temperature was controlled at 55℃, and the mixture was stirred for 1.5 hours. Aluminum sol and USY molecular sieve were then added to the reactor, and stirring continued for 5 hours. The mixture was spray-dried to form a catalyst, calcined at 480℃ for 30 minutes, washed with 8 times its volume of water, and dried in a 60℃ oven for 4 hours to obtain the catalyst sample. The dry basis mass ratio of kaolin to boehmite, rare earth solution, aluminum sol, and USY molecular sieve was 36.5%:15%:3%:5.5%:40%, and the final slurry solid content was 25%.
[0099] Comparative Example 5
[0100] Water, kaolin, boehmite, and rare earth solution were sequentially added to a stirred reactor. The pH was adjusted to 2.5, the temperature was controlled at 40℃, and the mixture was stirred for 1 hour. Aluminum sol and USY molecular sieve were then added to the reactor, and stirring continued for 0.5 hours. The mixture was spray-dried and calcined at 500℃ for 40 minutes. After washing with 7 times the amount of water, the mixture was dried in an oven at 120℃ for 3 hours to obtain the catalyst sample. The dry basis mass ratio of kaolin to boehmite, rare earth solution, aluminum sol, and USY molecular sieve was 52.2%:12%:0.8%:15%:20%, and the final slurry solid content was 34%.
[0101] A comparison of the pore distribution of the catalytic cracking catalyst support prepared in Example 1 with that of supports prepared from boehmite and kaolin is shown below. Figure 1 As shown, the pore size distribution of boehmite is concentrated around 3.4 nm, while the pore size of the support prepared in Example 1 is more widely distributed in the range of 2–100 nm, which is more conducive to the diffusion of heavy oil molecules in the catalytic cracking reaction. A comparison of the infrared acidity of the catalytic cracking catalyst support prepared in Example 1 and the support material prepared from boehmite shows... Figure 2 As shown in the figure, acid analysis reveals that boehmite is mainly composed of L acid, while the support prepared in Example 1 produces a large amount of Brønsted acid, which is beneficial for reducing coke selectivity.
[0102] The analytical results of pore volume, specific surface area, and microreactor activity of the catalysts prepared in Examples 1-5 and Comparative Examples 1-5 are shown in Table 1:
[0103] Table 1. Analysis results of the prepared catalyst
[0104]
[0105]
[0106] As shown in Table 1, the catalyst prepared in this invention has significantly improved pore volume, specific surface area and microreactor activity compared with conventional catalysts.
[0107] Table 2 shows the product distribution results of the catalysts prepared in Examples 1-5 and Comparative Examples 1-5 in the ACE unit:
[0108] Table 2 Evaluation results of the prepared catalyst
[0109]
[0110] As shown in Table 2, the catalyst prepared in this invention has a significantly higher conversion rate and a significantly lower coke yield / conversion rate compared with conventional catalysts.
Claims
1. A method for preparing a catalytic cracking catalyst, characterized in that, The specific steps are as follows: Step 1: Prepare a catalytic cracking catalyst support using bauxite; Step 2: Kaolin, boehmite, and rare earth solution are added sequentially to the catalytic cracking catalyst support obtained in Step 1 to obtain the first mixed slurry. The pH and temperature of the first mixed slurry are adjusted and aged to obtain the second mixed slurry. Step 3: Add aluminum sol and USY molecular sieve to the second mixed slurry in sequence and stir to obtain the third mixed slurry; Step 4: Spray dry the third mixed slurry to obtain the crude product of catalytic cracking catalyst. Then, calcine, wash with water, and dry the crude product of catalytic cracking catalyst to obtain the catalytic cracking catalyst.
2. The method for preparing the catalytic cracking catalyst according to claim 1, characterized in that, Step 1 specifically involves: Step 1.1: Grind bauxite to below 60 mesh to obtain bauxite powder. Roast the bauxite powder in a muffle furnace and cool it to room temperature to obtain activated bauxite powder. Step 1.2: Add the activated bauxite powder to a solution containing hydrochloric acid and phosphoric acid, then add the modifier, stir evenly, and obtain a slurry; Step 1.3: Heat the slurry in a sealed container and react at a constant temperature to obtain a catalytic cracking catalyst support.
3. The method for preparing the catalytic cracking catalyst according to claim 2, characterized in that, In step 1.1, the bauxite contains 55%-70% alumina by weight, 25%-40% silicon dioxide by weight, less than 0.8% sodium oxide by weight, less than 0.8% potassium oxide by weight, and less than 5% by weight of other impurities.
4. The method for preparing the catalytic cracking catalyst according to claim 2, characterized in that, In step 1.1, the bauxite powder is roasted in a muffle furnace at a temperature of 200℃-350℃ for a time of 10min-30min.
5. The method for preparing the catalytic cracking catalyst according to claim 2, characterized in that, In step 1.2, the mass ratio of hydrochloric acid to activated bauxite powder is 0.35-0.45:1, the mass ratio of phosphoric acid to activated bauxite powder is 0.08-0.2:1, the modifying material is ammonium borate, the mass ratio of ammonium borate to activated bauxite powder is 0.08-0.15:1, the stirring time is 5 min-15 min, and the solid content of the slurry is 35%-50%.
6. The method for preparing the catalytic cracking catalyst according to claim 2, characterized in that, In step 1.3, the sealed container is a stainless steel reactor with an acid and alkali resistant lining. The slurry heating rate is 5℃ / min-15℃ / min, the isothermal reaction temperature is 120℃-150℃, and the isothermal reaction time is 30min-120min.
7. The method for preparing the catalytic cracking catalyst according to claim 1, characterized in that, The dry weight ratio of the catalytic cracking catalyst support to kaolin is 1:0.6-9, the dry weight ratio of the catalytic cracking catalyst support to boehmite is 1:0.2-3, the dry weight ratio of the catalytic cracking catalyst support to rare earth solution is 1:0.01-0.3, the dry weight ratio of the catalytic cracking catalyst support to alumina sol is 1:0.15-3, and the dry weight ratio of the catalytic cracking catalyst support to USY molecular sieve is 1:0.6-8.
8. The method for preparing the catalytic cracking catalyst according to claim 1, characterized in that, In step 2, the solid content of the catalytic cracking catalyst support is 25%-40%, the pH of the first mixed slurry is adjusted to 2.5-4.0, the aging temperature is 30℃-65℃, and the aging time is 1h-2h.
9. The method for preparing the catalytic cracking catalyst according to claim 1, characterized in that, In step 3, after adding aluminum sol and USY molecular sieve to the second mixed slurry in sequence, the stirring time is 0.5h-5h.
10. The method for preparing the catalytic cracking catalyst according to claim 1, characterized in that, In step 4, the crude catalytic cracking catalyst is calcined at a temperature of 450℃-500℃ for 0.5h-1h, the mass ratio of water to crude catalytic cracking catalyst during washing is 5-8:1, the drying temperature is 60℃-150℃, and the drying time is 2h-4h.