A catalytic cracking catalyst resistant to nickel and vanadium contamination and a method of preparation

Abstract

The application discloses a kind of nickel, vanadium pollution-resistant catalytic cracking catalyst and preparation method.The preparation method includes the following steps: first raw material is mixed with water, and is beaten, then is formed by spraying, calcination, washing, drying, and the catalytic cracking catalyst is obtained;The first raw material includes boron phosphorus aluminum rare earth composition, molecular sieve, clay and binder;The boron phosphorus aluminum rare earth composition is the mixture of AlPO4 and B, P, Al, rare earth, and is calcined during preparation;B element can effectively inhibit nickel pollution, rare earth element can effectively capture V element, AlPO4 can effectively inhibit the dealumination of molecular sieve, offset the toxic effect of B, V and the like on catalyst;And in the preparation process of boron phosphorus aluminum rare earth composition, mesoporous structure is formed by calcination, boron is fixed in pore channel, and it is not easy to migrate to the surface of molecular sieve during the preparation of catalyst, damage the skeleton structure of molecular sieve, so that the catalyst can maintain relatively high activity stability.

Description

Technical Field

[0001] This invention relates to the field of catalytic cracking catalysts, specifically to a catalytic cracking catalyst resistant to nickel and vanadium contamination and its preparation method. Background Technology

[0002] In recent years, with the increasing depletion of oil resources, many refineries have begun to process inferior and heavier feedstocks in their catalytic cracking units for economic reasons. These heavy feedstocks often contain metals such as nickel, vanadium, iron, sodium, and calcium. These metals often deposit on the catalytic cracking catalyst, causing irreparable damage to the catalyst and thus affecting the operation of the entire catalytic cracking process.

[0003] Among these metals, nickel, vanadium, and iron have the greatest impact on catalysts. Vanadium forms vanadate under high-temperature steam, which leads to dealumination of the molecular sieve in the catalyst and a decrease in catalyst activity. Nickel's toxicity manifests as a strong catalytic dehydrogenation effect, which reduces the selectivity of catalytic cracking reactions and increases the yield of hydrogen and catalytic coke (coke generated by catalytic cracking reactions at acidic centers). Simultaneously, the presence of nickel exacerbates the destructive effect of vanadium on the molecular sieve. The presence of iron mainly manifests as the formation of a eutectic with low-melting-point components, forming iron nodules on the catalyst surface and blocking the catalyst's pores.

[0004] To reduce the poisoning effect of these metals on catalysts, the most common method is to add passivating agents to catalytic cracking units. Passivating agents are mainly compounds of antimony, bismuth, tin, rare earth elements, boron, etc., dispersed in a solvent and added to the feedstock. In the reactor, these metal compounds can react with nickel and vanadium to form relatively stable compounds, reducing the poisoning effect of nickel and vanadium on the catalyst. However, antimony-based, bismuth-based, and tin-based nickel passivating agents are highly toxic and cause significant environmental pollution, thus limiting their application.

[0005] The preparation technology of catalytic cracking catalysts resistant to heavy metal pollution involves modifying the physicochemical properties of the catalyst matrix, such as specific surface area, pore volume, and chemical composition, through various modification methods. Since heavy metals initially deposit on the surface of the catalyst matrix during catalytic cracking, this technology effectively captures them, protecting the active components of the molecular sieve. Currently, different preparation technologies for catalytic cracking catalysts resistant to heavy metal pollution have been developed and have become a research hotspot in the field of catalytic cracking. Summary of the Invention

[0006] The purpose of this invention is to provide a catalytic cracking catalyst resistant to nickel and vanadium contamination and its preparation method.

[0007] This invention prepares a boron-phosphorus-aluminum rare earth composition, which is added as an additive to a catalytic cracking catalyst to prepare a catalytic cracking catalyst resistant to nickel and vanadium metal contamination. The composition is a mixture of AlPO4 and B, P, Al, and rare earth elements. The presence of B effectively inhibits nickel metal contamination; the presence of rare earth elements effectively traps V, fixing V in the composition and preventing its migration to the molecular sieve components, thus greatly reducing the destructive effect of V on the molecular sieve; AlPO4 effectively inhibits the dealumination of the molecular sieve, counteracting the poisoning effects of B and V on the catalyst.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] The first aspect of this invention provides a method for preparing a catalytic cracking catalyst resistant to nickel and vanadium contamination, comprising the following steps:

[0010] The first raw material is mixed with water, pulped, and then spray-molded, calcined, washed, and dried to obtain the catalytic cracking catalyst; the first raw material includes a boron-phosphorus-aluminum rare earth composition, molecular sieve, clay, and binder.

[0011] The boron-phosphorus-aluminum rare earth composition is a mixture of AlPO4 and B, P, Al, and rare earth elements, and is subjected to calcination treatment during the preparation process.

[0012] According to the preparation method of the present invention, preferably, the first raw material further includes boehmite.

[0013] According to the preparation method of the present invention, preferably, the boron-phosphorus-aluminum rare earth composition is prepared by reacting aluminum compounds, phosphoric acid, boron compounds, rare earth compounds and dispersants and calcining at 400-700°C;

[0014] The boron compound is added at a boron content of 2 wt% to 6 wt% in the total mass of the boron-phosphorus-aluminum rare earth composition, more preferably 2 wt% to 4 wt%.

[0015] The aluminum compound and phosphoric acid are added in an Al:P molar ratio of (0.5-2.0):1, more preferably (0.9-1.5):1;

[0016] The rare earth compound is added at a rare earth element content of 1.5 wt% to 25 wt% in the total mass of the boron-phosphorus-aluminum rare earth composition;

[0017] The dispersant is added at 3 wt% to 15 wt% of the total mass of the boron-phosphorus-aluminum rare earth composition.

[0018] According to the preparation method of the present invention, preferably, the boron-phosphorus-aluminum rare earth composition is prepared by method one or method two:

[0019] Method 1: Add aluminum compound to water, then add phosphoric acid dropwise; then add boron compound, rare earth compound and dispersant, and stir to obtain a sol containing boron, phosphorus, aluminum and rare earth.

[0020] The sol containing boron, phosphorus, aluminum and rare earth elements is dried and calcined at 400-700°C for 1-4 hours to obtain the boron-phosphorus-aluminum-rare earth composition.

[0021] Method 2: Aluminum compounds are mixed and dispersed in water, then phosphoric acid is added dropwise, followed by rare earth compounds and a dispersant to obtain a sol containing phosphorus, aluminum, and rare earth elements; the sol containing phosphorus, aluminum, and rare earth elements is dried to obtain an intermediate product.

[0022] The boron compound was dissolved in water, loaded into the intermediate product by impregnation, dried, and calcined at 400-700°C for 1-4 hours to obtain the boron-phosphorus-aluminum rare earth composition.

[0023] In the preparation process of the boron-phosphorus-aluminum rare earth composition, the present invention forms a mesoporous structure through calcination, and the boron is fixed in the pores of the composition. During the preparation of the catalyst, it is not easy to migrate to the surface of the molecular sieve and destroy the framework structure of the molecular sieve, so that the catalyst can maintain a relatively high activity and stability. The rare earth in the composition can effectively capture vanadium metal, fix vanadium in the phosphorus and aluminum structure, greatly reduce the probability of it contacting the molecular sieve, and thus achieve a good anti-vanadium effect.

[0024] In both methods one and two, the calcination temperature is preferably 400–700°C, and the calcination time is preferably 1–4 hours. Furthermore, the drying temperature is 80–120°C, and the drying time is 5–24 hours. In the preparation process of the boron-phosphorus-aluminum rare earth composition of the present invention, in both methods one and two, after the addition of phosphoric acid, the mixture can be aged under stirring for a period of time, for example, 1–5 hours. In method one, it is preferable to continue stirring for 0.5–3 hours after adding the boron compound.

[0025] In the preparation of the boron-phosphorus-aluminum rare earth composition, preferably, the aluminum compound is selected from one or more combinations of alumina, boehmite, aluminum nitrate, and aluminum chloride. More preferably, the aluminum compound is aluminum nitrate or boehmite.

[0026] In the preparation of the boron-phosphorus-aluminum rare earth composition, preferably, the concentration of phosphoric acid is 20wt% to 85wt%, more preferably 30wt% to 70wt%.

[0027] In the preparation of the boron-phosphorus-aluminum rare earth composition, preferably, the boron compound is a soluble boron compound selected from one or more combinations of boron phosphate, boric acid, boron anhydride, ammonium borate, and ammonium fluoroborate. More preferably, the boron compound is boric acid or boron anhydride.

[0028] In the preparation of the boron-phosphorus-aluminum rare earth composition, preferably, the rare earth compound is a compound of lanthanum or cerium, more preferably a lanthanum or cerium nitrate, chloride, oxide or carbonate, and even more preferably a cerium nitrate or carbonate.

[0029] In the preparation process of the boron-phosphorus-aluminum rare earth composition, preferably, the dispersant is one or a combination of two or more of citric acid, tartaric acid, C2-8 alcohols, polyethylene glycol, cellulose derivatives, polyacrylamide and its derivatives, and glucon.

[0030] More preferably, the cellulose derivative is sodium hydroxymethylcellulose, methyl hydroxyethyl cellulose, or hydroxypropyl methylcellulose.

[0031] More preferably, the C2-8 alcohol is ethanol, ethylene glycol, glycerol, isopropanol, n-propanol or 1,3-butanediol.

[0032] In the preparation process of the catalytic cracking catalyst, preferably, the specific preparation process of the catalytic cracking catalyst includes:

[0033] The second raw material is added to water and mixed evenly. After aging, a binder is added to form a catalyst matrix slurry. The second raw material is a part of the first raw material, including the boron-phosphorus-aluminum rare earth composition and clay, or the second raw material includes the boron-phosphorus-aluminum rare earth composition, clay and boehmite.

[0034] The molecular sieve is added to water and sheared before being added to the catalyst matrix slurry. The slurry is then spray-molded, calcined, washed, and dried to obtain the catalytic cracking catalyst.

[0035] More preferably, the aging temperature is 40–90°C, more preferably 75°C, and the aging time is 1–5 hours, more preferably 1 hour.

[0036] In the preparation process of the catalytic cracking catalyst, when the first raw material is mixed with water and slurryed, the solid content of the system is preferably 10wt% to 45wt%. The calcination temperature of the catalytic cracking catalyst is preferably 400 to 800°C, and the calcination time is preferably 0.5 to 3 hours. More preferably, calcination is carried out at 500°C for 1 hour. The drying temperature is preferably 80 to 150°C, and the drying time is preferably 5 to 24 hours. The washing process uses water washing.

[0037] In the preparation process of the catalytic cracking catalyst, preferably, the raw materials corresponding to each component in the obtained catalytic cracking catalyst, based on dry basis oxides, are as follows: the content of the molecular sieve is 36wt% to 50wt%, the content of the boron-phosphorus-aluminum rare earth composition is 5wt% to 25wt%, the content of the clay is 21wt% to 43wt%, the content of the pseudoboehmite is 0 to 13wt%, and the content of the binder is 8wt% to 15wt%.

[0038] In the preparation process of the catalytic cracking catalyst, preferably, the molecular sieve is selected from one or a combination of two or more of RDSY molecular sieve, REY molecular sieve, β molecular sieve, and ZSM-5 molecular sieve.

[0039] In the preparation of the catalytic cracking catalyst, preferably, the clay is selected from one or more combinations of kaolinite, montmorillonite, and attapulgite.

[0040] In the preparation process of the catalytic cracking catalyst, preferably, the binder is selected from one or more combinations of alumina sol, silica sol, or colloidal alumina or silica materials.

[0041] The second aspect of the present invention provides a catalytic cracking catalyst resistant to nickel and vanadium contamination, which is prepared by the preparation method provided in the first aspect above.

[0042] The molecular sieve content in the nickel- and vanadium-resistant catalytic cracking catalyst, based on dry-basis oxides, is 36 wt% to 50 wt% of the raw materials corresponding to each component.

[0043] According to the nickel- and vanadium-contaminated catalytic cracking catalyst of the present invention, preferably, the content of the boron-phosphorus-aluminum rare earth composition in the raw materials corresponding to each component of the nickel- and vanadium-contaminated catalytic cracking catalyst, based on dry basis oxides, is 5 wt% to 25 wt%.

[0044] According to the nickel- and vanadium-contaminated catalytic cracking catalyst of the present invention, preferably, the clay content of each component in the nickel- and vanadium-contaminated catalytic cracking catalyst, based on dry basis oxides, is 21 wt% to 43 wt%.

[0045] According to the nickel- and vanadium-contaminated catalytic cracking catalyst of the present invention, preferably, the content of the pseudoboehmite in the raw materials corresponding to each component of the nickel- and vanadium-contaminated catalytic cracking catalyst, based on dry basis oxides, is 0-13 wt%, preferably 5-13 wt%.

[0046] According to the nickel- and vanadium-contaminated catalytic cracking catalyst of the present invention, preferably, the content of the binder in the raw materials corresponding to each component of the nickel- and vanadium-contaminated catalytic cracking catalyst, based on dry basis oxides, is 8 wt% to 15 wt%.

[0047] This invention incorporates a boron-phosphorus-aluminum rare earth composition as an additive in catalyst preparation to obtain a catalytic cracking catalyst resistant to nickel and vanadium contamination. This composition is a mixture of AlPO4 and B, P, Al, and rare earth elements. The presence of boron effectively inhibits nickel metal contamination; the presence of rare earth elements effectively traps vanadium (V), fixing V within the composition and preventing its migration to the molecular sieve components, thus significantly reducing the destructive effect of V on the molecular sieve; the presence of AlPO4 effectively inhibits dealumination of the molecular sieve, counteracting the poisoning effects of B and V on the catalyst.

[0048] During the preparation of boron-phosphorus-aluminum rare earth composition, boron is fixed in the pores of the composition by calcination to form a mesoporous structure. During the preparation of the catalyst, boron does not easily migrate to the surface of the molecular sieve and destroy the framework structure of the molecular sieve, thus enabling the catalyst to maintain relatively high activity stability. Detailed Implementation

[0049] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0050] All numerical specifications in this invention (e.g., temperature, time, concentration, and weight, including ranges for each) are generally approximate values ​​that may be changed (+) or (-) in increments of 0.1 or 1.0. All numerical specifications are to be understood as being preceded by the term "about".

[0051] The raw materials and their properties used in the following examples are as follows:

[0052] Kaolin, silica sol (40 wt% solids), alumina sol (18 wt% solids), various molecular sieves, boehmite (dry basis, molecular weight 101.96 after deduction of loss on ignition), and hydrochloric acid (30 wt% concentration) are all industrial grade; nickel nitrate, boric acid, boric anhydride, aluminum nitrate, aluminum chloride, ammonium metavanadate, oxalic acid, cerium nitrate, cerium carbonate, lanthanum oxide, glycerol, ethylene glycol, isopropanol, n-propanol, 1,3-butanediol, methyl hydroxyethyl cellulose, hydroxypropyl methyl cellulose, and sodium hydroxymethyl cellulose are all analytical grade. Phosphoric acid 85 wt%.

[0053] Catalyst microreaction activity evaluation method: The microreaction activity evaluation device developed by Beijing Huier Sanji Green Chemical Technology Co., Ltd. was used for evaluation. The feedstock oil used was the 3 million tons / year catalyst feedstock of Lanzhou Petrochemical Company, and the properties of the feedstock oil are shown in Table 1. The catalyst was aged at 800℃ and 100% steam for 17 hours before evaluation.

[0054] Catalyst reaction performance evaluation methods:

[0055] Before evaluation, the catalyst was subjected to heavy metal contamination. The method for heavy metal contamination simulated the nickel and v content in industrial applications: an aqueous solution of nickel nitrate, ammonium metavanadate, and a solution of oxalic acid (10,000 ppm Ni and 5,000 ppm V based on the dry weight of the catalyst) were impregnated into the catalyst. After drying at 120°C, the catalyst was calcined at 550°C for 4 hours. The reaction performance was evaluated using an ACE unit. The feedstock used was the 3 million tons / year catalyst feedstock from Lanzhou Petrochemical Company, and its properties are shown in Table 1. Before evaluation, the catalyst was aged at 800°C with 100% steam for 8 hours.

[0056] Table 1 Properties of Crude Oil

[0057]

[0058]

[0059] Preparation of boron-phosphorus-aluminum rare earth composition:

[0060] Composition 1

[0061] 2129.96g of aluminum nitrate (Al: 10mol) was added to 3L of water under stirring until dissolved. 1152.94g of 85wt% phosphoric acid (P: 10mol) was added dropwise to the dissolved aluminum nitrate to form a homogeneous sol. Then, 186g of boric acid (B: 3mol), 386g of cerium nitrate, and 15.27g of glycerol were added, and stirring was continued for 0.5h. The sol was dried in an oven at 100℃ for 24h and calcined at 600℃ for 1h to obtain composition 1.

[0062] Composition 2

[0063] 1019.60 g of dry-based pseudoboehmite (Al: 10 mol) was dispersed in 3 L of water under stirring. The mixture was stirred continuously for 0.5 h. 700.00 g of 70 wt% phosphoric acid (P: 5 mol) was added dropwise under stirring to form a homogeneous sol. The mixture was stirred for another 1 h. Then, 222.78 g of boron anhydride (B: 6.4 mol), 102.2 g of cerium carbonate, 42.7 g of methyl hydroxyethyl cellulose, and 43.2 g of ethylene glycol were added. The mixture was stirred for another 1 h. The sol was dried in an oven at 80 °C for 20 h and calcined at 500 °C for 2 h to obtain composition 2.

[0064] Composition 3

[0065] 1333.40 g of aluminum chloride (Al: 10 mol) was dissolved in 1 L of water under stirring. 6533.33 g of 30 wt% phosphoric acid (P: 20 mol) was added dropwise under stirring to form a homogeneous sol. Stirring was continued for 2 h. Then, 742.07 g of ammonium borate trihydrate (B: 13 mol), 22.94 g of cerium oxide, 20.00 g of sodium carboxymethyl cellulose and 16.15 g of isopropanol were added, and stirring was continued for 1 h. The sol was dried in an oven at 120 °C for 6 h and calcined at 450 °C for 3 h to obtain composition 3.

[0066] Composition 4

[0067] 2129.96g of aluminum nitrate (Al: 10mol) was added to 2L of water under stirring until dissolved. 1633.33g of 40wt% phosphoric acid (P: 6.7mol) was added dropwise to the dissolved aluminum nitrate to form a homogeneous sol. Then, 281.05g of ammonium fluoroborate (B: 2.7mol), 511.71g of lanthanum chloride, 100g of n-propanol and 32.5g of hydroxypropyl methylcellulose were added, and stirring was continued for 0.5h. The sol was dried in an oven at 150℃ for 7h and calcined at 400℃ for 4h to obtain composition 4.

[0068] Composition 5

[0069] 1333.40g of aluminum chloride (Al: 10mol) was dissolved in 1L of water under stirring. 6533.33g of 30wt% phosphoric acid (P: 20mol) was added dropwise under stirring. The mixture was stirred and aged for 3 hours. 458.55g of lanthanum nitrate and 361.94g of 1,3-butanediol were added to form a sol. The sol was dried in an oven at 130℃ for 16 hours and then ground into powder.

[0070] Dissolve 354g of boric acid (B: 5.7mol) in 500mL of water, add it to the above powder and soak for 1h, dry at 120℃ for 5h, and calcine at 450℃ for 3h to obtain composition 5.

[0071] Comparative composition 1

[0072] 1019.60 g of dry-based pseudoboehmite (Al: 10 mol) was dispersed in 2.5 L of water under stirring. The mixture was stirred continuously for 0.5 h. 700.00 g of 70 wt% phosphoric acid (P: 10 mol) was added dropwise while stirring. The mixture was then stirred and aged for 1 h. After that, 222.78 g of boron anhydride (B: 6.4 mol) was added and stirred for 1 h. Then, 102.2 g of cerium carbonate, 45.7 g of methyl hydroxyethyl cellulose, and 42.0 g of ethylene glycol were added and stirred for 1 h. The sol was then dried in an oven at 110 °C for 10 h to obtain comparative composition 1.

[0073] Comparative composition 2

[0074] 1019.60g of dry-based pseudoboehmite was dispersed in 3L of water under stirring and stirred continuously for 0.5h. 700.00g of 70wt% phosphoric acid was added dropwise while stirring, and the mixture was aged for another 1h. Then 208.86g of boron anhydride was added and the mixture was stirred for another 1h. The sol was dried in an oven at 120℃ for 8h and calcined at 500℃ for 2h to obtain comparative composition 2.

[0075] Comparative composition 3

[0076] 1019.60g of dry-based pseudoboehmite was dispersed in 3L of water under stirring for 0.5h. Then, 151.89g of boron anhydride was added and stirred for 1h. 73.00g of cerium carbonate, 18.0g of methyl hydroxyethyl cellulose and 42.0g of ethylene glycol were added and stirred for another 1h. The sol was dried in an oven at 120℃ for 8h and calcined at 500℃ for 2h to obtain comparative composition 3.

[0077] Comparative composition 4

[0078] 1019.60g of dry-based pseudoboehmite was dispersed in 3L of water under stirring and stirred continuously for 0.5h. 700.00g of 70wt% phosphoric acid was added dropwise while stirring, and the mixture was aged for another 1h. Then, 87.45g of cerium carbonate, 29.75g of methyl hydroxyethyl cellulose and 42.0g of ethylene glycol were added, and the mixture was stirred for another 1h. The sol was dried in an oven at 120℃ for 8h and calcined at 500℃ for 2h to obtain comparative composition 4.

[0079] The composition and partial preparation conditions of the above-obtained compositions 1-5 and comparative compositions 1-4 are shown in Table 2.

[0080] Table 2 Composition and preparation conditions of compositions 1-5 and comparative compositions 1-4

[0081]

[0082] Example 1

[0083] This embodiment uses composition 1 to prepare catalytic cracking catalyst S1, including the following steps:

[0084] In a reactor equipped with a water bath heating system, 2.5L of water, 870g of kaolin, and 150g of boehmite were added. Then, 90g of hydrochloric acid was slowly added and mixed thoroughly. After stirring for 1 hour, the mixture was aged at 75℃ for 1 hour. Then, 1666g of aluminum sol and 600g of composition 1 were added and stirring was continued to form a catalyst matrix slurry. 2L of water and 1080g of RDSY molecular sieve were added to a slurry tank. After passing through a high-speed shearing machine for 20 minutes, the mixture was added to the catalyst matrix slurry. After slurrying for 1 hour, the mixture was spray-formed. The resulting microspheres were calcined at 500℃ for 1 hour, washed with water, and dried at 150℃ for 5 hours to obtain catalyst S1.

[0085] Example 2

[0086] This embodiment uses composition 2 to prepare catalytic cracking catalyst S2, including the following steps:

[0087] In a reactor equipped with a water bath heating system, 2L of water and 840g of attapulgite were added, mixed evenly, and stirred for 1 hour. After stirring, the mixture was aged at 75℃ for 1 hour. Then, 1833g of aluminum sol and 750g of composition 2 were added and stirring was continued to form a catalyst matrix slurry. 1.7L of water and 980g of RDSY + 100g of REY molecular sieve were added to a slurry tank. After passing through a high-speed shearing machine for 20 minutes, the mixture was added to the catalyst matrix slurry and slurried for 1 hour. After spray molding, the resulting microspheres were calcined at 500℃ for 1 hour, washed with water, and dried at 110℃ for 12 hours to obtain catalyst S2.

[0088] Example 3

[0089] This embodiment uses composition 3 to prepare catalytic cracking catalyst S3, including the following steps:

[0090] In a reactor equipped with a water bath heating system, 3.5L of water, 1140g of montmorillonite, and 390g of boehmite were added and mixed evenly. 190g of hydrochloric acid was added dropwise, and the mixture was stirred for 1 hour. After aging at 75℃ for 1 hour, 1333g of aluminum sol and 150g of composition 3 were added and the mixture was stirred to form a catalyst matrix slurry. 4L of water was added to a slurry tank, along with 980g of RDSY and 100g of REY molecular sieve. After passing through a high-speed shearing machine for 20 minutes, the mixture was added to the catalyst matrix slurry and slurried for 1 hour. After spray molding, the resulting microspheres were calcined at 500℃ for 1 hour, washed with water, and dried at 120℃ for 5 hours to obtain catalyst S3.

[0091] Example 4

[0092] This embodiment uses composition 4 to prepare catalytic cracking catalyst S4, including the following steps:

[0093] In a reactor equipped with a water bath heating system, 2.5L of water, 1140g of halloysite, and 180g of boehmite were added and mixed evenly. 90g of hydrochloric acid was added dropwise, and the mixture was stirred for 1 hour. After aging at 75℃ for 1 hour, 1333g of aluminum sol and 300g of composition 4 were added and stirring was continued to form a catalyst matrix slurry. 3.5L of water and 1080g of RDSY molecular sieve were added to a slurry tank. After passing through a high-speed shearing machine for 20 minutes, the mixture was added to the catalyst matrix slurry and slurried for 1 hour. After spray molding, the resulting microspheres were calcined at 500℃ for 1 hour, washed with water, and dried at 100℃ for 24 hours to obtain catalyst S4.

[0094] Example 5

[0095] This embodiment uses composition 5 to prepare catalytic cracking catalyst S5, including the following steps:

[0096] In a reactor equipped with a water bath heating system, 3.5L of water, 840g of kaolin, and 240g of boehmite were added and mixed evenly. 120g of hydrochloric acid was added dropwise, and the mixture was stirred for 1 hour. After aging at 75℃ for 1 hour, 1125g of silica sol and 450g of composition 5 were added and the mixture was stirred continuously to form a catalyst matrix slurry. 3.0L of water and 600g of β-molecular sieve were added to a slurry tank. After passing the mixture through a high-speed shearing machine for 20 minutes, the mixture was added to the catalyst matrix slurry and slurried for 1 hour. After spray molding, the resulting microspheres were calcined at 500℃ for 1 hour, washed with water, and dried at 80℃ for 24 hours to obtain catalyst S5.

[0097] Example 6

[0098] This embodiment uses composition 2 to prepare catalytic cracking catalyst S6, including the following steps:

[0099] In a reactor equipped with a water bath heating system, 4L of water, 1050g of kaolin, and 270g of boehmite were added and mixed evenly. 130g of hydrochloric acid was added dropwise, and the mixture was stirred for 1 hour. After aging at 75℃ for 1 hour, 900g of silica sol and 4240g of composition 2 were added and the mixture was stirred to form a catalyst matrix slurry. 4L of water and 900g of RDSY + 600g of ZSM-5 molecular sieve were added to a slurry tank. After passing the mixture through a high-speed shearing machine for 20 minutes, the mixture was added to the catalyst matrix slurry and slurried for 1 hour. After spray molding, the resulting microspheres were calcined at 500℃ for 1 hour, washed with water, and dried at 120℃ for 6 hours to obtain catalyst S6.

[0100] Comparative Example 1

[0101] This comparative example prepares catalytic cracking catalyst D1, which does not use a boron-phosphorus-aluminum rare earth composition, and includes the following steps:

[0102] In a reactor equipped with a water bath heating system, 2.5L of water, 1470g of kaolin, and 150g of boehmite were added. Then, 90g of hydrochloric acid was slowly added and mixed thoroughly. After stirring for 1 hour, the mixture was aged at 75℃ for 1 hour. Then, 1666g of aluminum sol was added to form a catalyst matrix slurry. 2L of water and 1080g of RDSY molecular sieve were added to a slurry tank. After passing the sieve through a high-speed shearing machine for 20 minutes, it was added to the catalyst matrix slurry. After slurrying for 1 hour, the mixture was spray-formed. The resulting microspheres were calcined at 500℃ for 1 hour, washed with water, and dried at 100℃ for 16 hours to obtain catalyst D1.

[0103] Comparative Example 2

[0104] This comparative example prepares catalytic cracking catalyst D2, wherein boric acid is used instead of the boron-phosphorus-aluminum rare earth composition, and includes the following steps:

[0105] In a reactor equipped with a water bath heating system, 2.5L of water, 1470g of kaolin, 150g of borosilicate, and 422g of boric acid were added, followed by the slow addition of 90g of hydrochloric acid. After stirring for 1 hour, the mixture was aged at 75℃ for 1 hour. Then, 1666g of aluminum sol was added to form a catalyst matrix slurry. 2L of water and 1080g of RDSY molecular sieve were added to a slurry tank. After passing the sieve through a high-speed shearing machine for 20 minutes, the slurry was added to the catalyst matrix slurry. After slurrying for 1 hour, the slurry was spray-formed. The resulting microspheres were calcined at 500℃ for 1 hour, washed with water, and dried at 110℃ for 10 hours to obtain catalyst D2.

[0106] Comparative Example 3

[0107] This comparative example prepares catalytic cracking catalyst D3, wherein rare earth compounds (1 wt% of rare earth content on a dry basis) and dispersants are used instead of the boron-phosphorus-aluminum rare earth composition, and includes the following steps:

[0108] In a reactor equipped with a water bath heating system, 2.5 L of water, 1394 g of kaolin, and 150 g of boehmite were added. Then, 90 g of hydrochloric acid was slowly added and mixed thoroughly. After stirring for 1 hour, the mixture was aged at 75 °C for 1 hour. Then, 1666 g of aluminum sol, 75.69 g of cerium nitrate, 45.7 g of methyl hydroxyethyl cellulose, and 46.0 g of ethylene glycol were added to form a catalyst matrix slurry. 2 L of water and 1080 g of RDSY molecular sieve were added to a slurry tank. After passing the slurry through a high-speed shearing machine for 20 minutes, the slurry was added to the catalyst matrix slurry. After slurrying for 1 hour, the slurry was spray-formed. The resulting microspheres were calcined at 500 °C for 1 hour, washed with water, and dried at 150 °C for 4 hours to obtain catalyst D3.

[0109] Comparative Example 4

[0110] This comparative example prepares catalytic cracking catalyst D4, wherein comparative composition 1 is used instead of the boron-phosphorus-aluminum rare earth composition, and includes the following steps:

[0111] In a reactor equipped with a water bath heating system, 3.5 L of water, 840 g of kaolin, and 240 g of pseudo-thin were added and mixed evenly. 120 g of hydrochloric acid was added dropwise, and the mixture was stirred for 1 hour. After aging at 75 °C for 1 hour, 1125 g of silica sol and 450 g of control composition 1 were added, and stirring was continued to form a catalyst matrix slurry. 3.0 L of water and 1080 g of RDSY molecular sieve were added to a slurry tank. After passing through a high-speed shearing machine for 20 minutes, the mixture was added to the catalyst matrix slurry and slurried for 1 hour. After spray molding, the resulting microspheres were calcined at 500 °C for 1 hour, washed with water, and dried at 130 °C for 12 hours to obtain catalyst D4.

[0112] Comparative Example 5

[0113] This comparative example prepares catalytic cracking catalyst D5, wherein comparative composition 2, rare earth compounds, and dispersants are used instead of the boron-phosphorus-aluminum rare earth composition, and includes the following steps:

[0114] In a reactor equipped with a water bath heating system, 2.5 L of water, 840 g of kaolin, and 150 g of boehmite were added. Then, 90 g of hydrochloric acid was slowly added and mixed thoroughly. After stirring for 1 hour, the mixture was aged at 75 °C for 1 hour. Then, 1666 g of aluminum sol, 600 g of comparative composition 2, 75.69 g of cerium nitrate, 45.7 g of methyl hydroxyethyl cellulose, and 46.0 g of ethylene glycol were added, and stirring was continued to form a catalyst matrix slurry. 2 L of water and 1080 g of RDSY molecular sieve were added to a slurry tank. After passing the sieve through a high-speed shearing machine for 20 minutes, it was added to the catalyst matrix slurry. After slurrying for 1 hour, the mixture was spray-formed. The resulting microspheres were calcined at 500 °C for 1 hour, washed with water, and dried at 120 °C for 12 hours to obtain catalyst D5.

[0115] Comparative Example 6

[0116] This comparative example prepares catalytic cracking catalyst D6, wherein comparative composition 3 is used instead of the boron-phosphorus-aluminum rare earth composition, and includes the following steps:

[0117] In a reactor equipped with a water bath heating system, 2.5L of water, 870g of kaolin, and 150g of pseudoboehmite were added. Then, 90g of hydrochloric acid was slowly added and mixed thoroughly. After stirring for 1 hour, the mixture was aged at 75℃ for 1 hour. Then, 1666g of aluminum sol and 600g of control composition 3 were added, and stirring was continued to form a catalyst matrix slurry. 2L of water and 1080g of RDSY molecular sieve were added to a slurry tank. After passing through a high-speed shearing machine for 20 minutes, the mixture was added to the catalyst matrix slurry. After slurrying for 1 hour, the mixture was spray-formed. The resulting microspheres were calcined at 500℃ for 1 hour, washed with water, and dried at 120℃ for 10 hours to obtain catalyst D6.

[0118] Comparative Example 7

[0119] This comparative example prepares catalytic cracking catalyst D7, wherein comparative composition 4 is used instead of the boron-phosphorus-aluminum rare earth composition, and includes the following steps:

[0120] In a reactor equipped with a water bath heating system, 2.5L of water, 870g of kaolin, and 150g of boehmite were added. Then, 90g of hydrochloric acid was slowly added and mixed thoroughly. After stirring for 1 hour, the mixture was aged at 75℃ for 1 hour. Then, 1666g of aluminum sol and 600g of control composition 4 were added, and stirring was continued to form a catalyst matrix slurry. 2L of water and 1080g of RDSY molecular sieve were added to a slurry tank. After passing through a high-speed shearing machine for 20 minutes, the mixture was added to the catalyst matrix slurry. After slurrying for 1 hour, the mixture was spray-formed. The resulting microspheres were calcined at 500℃ for 1 hour, washed with water, and dried at 100℃ for 24 hours to obtain catalyst D7.

[0121] Comparative Example 8

[0122] This comparative example prepares catalytic cracking catalyst D8, in which boric acid and phosphoric acid (both accounting for 3% of the catalyst dry basis) are used instead of the boron-phosphorus-aluminum rare earth composition, including the following steps:

[0123] In a reactor equipped with a water bath heating system, 2.5 L of water, 1380 g of kaolin, and 150 g of borosilicate were added. Then, 90 g of hydrochloric acid and 422 g of boric acid were slowly added and mixed thoroughly. After stirring for 1 hour, the mixture was aged at 75 °C for 1 hour. 75.69 g of cerium nitrate, 45.7 g of methyl hydroxyethyl cellulose, and 46.0 g of ethylene glycol were added and stirred for 1 hour. Then, 1666 g of aluminum sol and 35.8 g of 85 wt% phosphoric acid were added, and stirring was continued to form a catalyst matrix slurry. 2 L of water and 1080 g of RDSY molecular sieve were added to a slurry tank. After passing through a high-speed shearing machine for 20 minutes, the mixture was added to the catalyst matrix slurry and slurried for 1 hour. After spray molding, the resulting microspheres were calcined at 500 °C for 1 hour, washed with water, and dried at 100 °C for 24 hours to obtain catalyst D8.

[0124] The composition of the raw materials corresponding to each component of catalysts S1-S6 and D1-D8 is shown in Table 3 below, the activity data is shown in Table 4 below, and the ACE evaluation results of the contaminated samples (contaminated with 12000ppm nickel) are shown in Table 5.

[0125] As shown in Table 4, catalysts S1-S6 in the examples still exhibited relatively high activity after aging in water vapor at 800℃ for 17 hours. The activity of catalysts D2, D4, D6, and D8 decreased significantly, indicating that the method of adding boron (B) affects the structure of the molecular sieve. The presence of AlPO4 in the boron-phosphorus-aluminum composition of the present invention can effectively inhibit the dealumination of the molecular sieve, offsetting the poisoning effect of B on the catalyst. Simultaneously, during the preparation of the boron-phosphorus-aluminum rare earth composition, a mesoporous structure is formed through calcination, and boron is fixed in the pores of the composition. During catalyst preparation, it is difficult for boron to migrate to the surface of the molecular sieve and disrupt its framework structure, thus enabling catalysts S1-S6 to maintain relatively high activity stability after aging in water vapor at 800℃ for 17 hours. In D2, boric acid was used instead of the boron-phosphorus-aluminum rare earth composition; in D4, uncalcined comparative composition 1 was used instead of the boron-phosphorus-aluminum rare earth composition; in D6, phosphorus-free comparative composition 3 was used instead of the boron-phosphorus-aluminum rare earth composition; and in D8, boric acid and phosphoric acid were used instead of the boron-phosphorus-aluminum composition. All of these methods resulted in a significant decrease in activity.

[0126] As shown in Table 5, after being contaminated with 10,000 ppm nickel and 5,000 ppm vanadium, catalysts S1-S6 showed higher conversion rates and relatively lower H2 / CH4 ratios compared to the comparative catalysts D1 and D3, indicating that the addition of the composition in the examples helped resist nickel. Compared to catalyst D2, the catalyst samples in the examples showed relatively higher conversion rates and relatively lower H2 / CH4 ratios, indicating that the addition of boron in the composition as described in the examples had a better nickel resistance effect. Compared to catalyst D5, the conversion rates of the examples were higher, indicating that the addition of rare earth elements as described in the examples had a better vanadium resistance effect. Compared to catalyst D4, the conversion rates of the catalyst samples in the examples were relatively higher, indicating that the calcined composition had a better metal resistance effect. Compared to D6, D7, and D8, examples S1-S6 showed relatively higher conversion rates, indicating that the phosphorus-boron-aluminum rare earth composition, when added as described in the examples, simultaneously had both vanadium and nickel resistance effects.

[0127] Table 3. Composition of the raw materials corresponding to each component in the catalysts obtained in the examples and comparative examples (based on dry oxides).

[0128]

[0129] Table 4 Catalyst activity (MAT, 800℃×17h)

[0130]

[0131] Table 5. ACE evaluation results of each catalyst contamination sample.

[0132]

[0133] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for preparing a catalytic cracking catalyst resistant to nickel and vanadium contamination, wherein, The preparation method includes the following steps: The first raw material is mixed with water, pulped, and then spray-molded, calcined, washed, and dried to obtain the catalytic cracking catalyst; the first raw material includes a boron-phosphorus-aluminum rare earth composition, molecular sieve, clay, and binder. The boron-phosphorus-aluminum rare earth composition is a mixture of AlPO4 and B, P, Al, and rare earth elements. The boron-phosphorus-aluminum rare earth composition is prepared by reacting aluminum compounds, phosphoric acid, boron compounds, rare earth compounds, and dispersants and then calcining at 400~700℃. The boron compound is added at a boron content of 2 wt% to 6 wt% in the total mass of the boron-phosphorus-aluminum rare earth composition. The aluminum compound and phosphoric acid were added at an Al:P molar ratio of (0.5~2.0):1; The rare earth compound is added at a rare earth element content of 1.5wt% to 25wt% in the total mass of the boron-phosphorus-aluminum rare earth composition; The dispersant is added at 3wt% to 15wt% of the total mass of the boron-phosphorus-aluminum rare earth composition; The boron-phosphorus-aluminum rare earth composition is prepared by either method one or method two: Method 1: Add aluminum compound to water, then add phosphoric acid dropwise; then add boron compound, rare earth compound and dispersant, and stir to obtain a sol containing boron, phosphorus, aluminum and rare earth. The sol containing boron, phosphorus, aluminum and rare earth elements is dried and calcined at 400~700℃ for 1 h~4 h to obtain the boron-phosphorus-aluminum-rare earth composition. Method 2: Aluminum compounds are mixed and dispersed in water, then phosphoric acid is added dropwise, followed by rare earth compounds and a dispersant to obtain a sol containing phosphorus, aluminum, and rare earth elements; the sol containing phosphorus, aluminum, and rare earth elements is dried to obtain an intermediate product. The boron compound was dissolved in water, loaded into the intermediate product by impregnation, dried, and calcined at 400-700°C for 1-4 hours to obtain the boron-phosphorus-aluminum rare earth composition.

2. The preparation method according to claim 1, wherein, The first raw material also includes boehmite.

3. The preparation method according to claim 1, wherein, The aluminum compound is selected from one or more of alumina, boehmite, aluminum nitrate, and aluminum chloride.

4. The preparation method according to claim 1, wherein, The boron compound is selected from one or more of boron phosphate, boric acid, boron anhydride, ammonium borate, and ammonium fluoroborate.

5. The preparation method according to claim 1, wherein, The rare earth compound is a nitrate, chloride, oxide, or carbonate of lanthanum or cerium.

6. The preparation method according to claim 1, wherein, The dispersant is one or a combination of two or more of the following: citric acid, tartaric acid, C2-C8 alcohols, polyethylene glycol, cellulose derivatives, polyacrylamide and its derivatives, and glucon.

7. The preparation method according to claim 1, wherein, The specific preparation process of the catalytic cracking catalyst includes: The second raw material is added to water and mixed evenly. After aging, a binder is added to form a catalyst matrix slurry. The second raw material includes the boron-phosphorus-aluminum rare earth composition and clay. The molecular sieve is added to water and sheared before being added to the catalyst matrix slurry. The slurry is then spray-molded, calcined, washed, and dried to obtain the catalytic cracking catalyst.

8. The preparation method according to claim 2, wherein, The specific preparation process of the catalytic cracking catalyst includes: The second raw material is added to water and mixed evenly. After aging, a binder is added to form a catalyst matrix slurry. The second raw material includes the boron-phosphorus-aluminum rare earth composition, clay, and boehmite. The molecular sieve is added to water and sheared before being added to the catalyst matrix slurry. The slurry is then spray-molded, calcined, washed, and dried to obtain the catalytic cracking catalyst.

9. The preparation method according to claim 1, wherein, The calcination temperature of the catalytic cracking catalyst is 400~800℃, and the calcination time is 0.5~3 h.

10. The preparation method according to claim 2, wherein, The raw materials corresponding to each component in the obtained catalytic cracking catalyst, calculated on a dry basis as oxides, are as follows: the content of the molecular sieve is 36wt%~50wt%, the content of the boron-phosphorus-aluminum rare earth composition is 5wt%~25wt%, the content of the clay is 21wt%~43wt%, the content of the pseudoboehmite is greater than 0 and less than or equal to 13wt%, and the content of the binder is 8wt%~15wt%.

11. The preparation method according to claim 1, wherein, The molecular sieve is selected from one or more of RDSY molecular sieve, REY molecular sieve, β molecular sieve, and ZSM-5 molecular sieve.

12. The preparation method according to claim 1, wherein, The clay is selected from one or more of the following: kaolin, malachite, montmorillonite, and attapulgite.

13. The preparation method according to claim 1, wherein, The binder is selected from one or a combination of two of aluminum sol and silica sol.

14. The preparation method according to claim 1, wherein, The binder is selected from one or more of colloidal alumina or silica materials.

15. A catalytic cracking catalyst resistant to nickel and vanadium contamination prepared by the preparation method according to any one of claims 1-14.

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