Catalytic cracking catalyst against heavy metal nickel pollution and preparation method thereof

Abstract

The application discloses a kind of anti-heavy metal nickel pollution catalytic cracking catalyst and preparation method.The preparation method includes the following steps: first raw material is mixed with water, beating, then by spray forming, calcination, washing, drying, obtain the catalytic cracking catalyst;The first raw material includes boron phosphorus aluminum composition, molecular sieve, clay and binder.The boron phosphorus aluminum composition is AlPO4 and the mixture of B, P, Al, and is calcined during preparation process.B element can effectively inhibit the pollution of nickel metal, AlPO4 can effectively inhibit the dealumination of molecular sieve, offset the toxic effect of B on catalyst;And in the preparation process of boron phosphorus aluminum composition, mesoporous structure is formed by calcination, boron is fixed in the pore of composition, not easy to migrate to the surface of molecular sieve during the preparation process of catalyst, destroy the framework structure of molecular sieve, so that the catalyst can maintain relatively high activity stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalytic cracking catalysts, in particular to a catalytic cracking catalyst resistant to heavy metal nickel pollution and a preparation method thereof. BACKGROUND

[0002] Catalytic cracking (FCC) is an important means of petroleum processing. At present, with the increasing depletion of petroleum resources, the feedstock oil for catalytic cracking is becoming increasingly heavy and inferior, and the content of metals such as nickel and vanadium is increasing. Nickel in the feedstock oil mainly exists in the form of porphyrin nickel and other heterocyclic compounds. During the catalytic cracking process, the metal nickel will deposit on the surface of the catalyst. The toxicity of nickel is manifested in strong catalytic dehydrogenation, which makes the selectivity of catalytic cracking reaction worse and increases the yield of hydrogen and catalytic coke (catalytic coke generated on the acid center by catalytic cracking reaction).

[0003] At present, the technologies for resisting heavy metal nickel pollution in FCC mainly include: (1) application of nickel passivator; and (2) preparation of a catalytic cracking catalyst resistant to nickel pollution.

[0004] The nickel passivator is mainly a compound of antimony, bismuth, tin, rare earth, boron and the like dispersed in a solvent and added to the feedstock oil. In the reactor, these metal compounds can react with nickel to form relatively stable compounds, thereby reducing the dehydrogenation activity of nickel. However, the antimony-based, bismuth-based and tin-based nickel passivators have strong toxicity and cause great pollution to the environment, thereby limiting their application. The rare earth-based and boron-based nickel passivators have relatively low toxicity and can achieve the same nickel passivation effect as the first three, but they need suitable solvents and dispersants to dissolve and disperse these compounds, thereby increasing the production and transportation costs. Moreover, if it is a water-based passivator, it is easy to freeze, which affects the large-scale application of the passivator.

[0005] The preparation technology of the FCC catalyst resistant to heavy metal pollution is to adjust the specific surface, pore volume and chemical composition of the FCC catalyst matrix by different modification methods. Since the heavy metal is first deposited on the surface of the catalyst matrix during the FCC process, the heavy metal is captured on the surface of the matrix in time to protect the active component of the molecular sieve. At present, different preparation technologies of the FCC catalyst resistant to heavy metal pollution have been developed by people one after another, and have become a hot spot in the field of FCC. For example, the FCC catalyst is modified by alkaline earth metals, copper, zinc, cadmium and tungsten or compounds, thereby improving the resistance of the catalyst to heavy metal pollution. However, the effect of the metal-modified catalytic cracking catalyst on resisting heavy metal nickel pollution is not obvious, especially under the condition of high content of nickel, the nickel passivation effect is poorer. SUMMARY

[0006] The present application aims to provide a catalytic cracking catalyst resistant to heavy metal nickel pollution and a preparation method thereof.

[0007] The present application prepares a boron-phosphorus-aluminum composition, adds the composition as an additive component into a catalytic cracking catalyst, and prepares a catalytic cracking catalyst resistant to nickel metal pollution. The composition is a mixture of AlPO4 and B, P, and Al. The presence of B effectively inhibits nickel metal pollution, and AlPO4 effectively inhibits dealumination of the molecular sieve and offsets the poisoning effect of B on the catalyst.

[0008] To achieve the above object, the present application adopts the following technical solutions:

[0009] The first aspect of the present application provides a preparation method of a catalytic cracking catalyst resistant to heavy metal nickel pollution, comprising the following steps:

[0010] The first raw material is mixed with water, beaten, and then formed by spraying, calcined, washed, and dried to obtain the catalytic cracking catalyst.

[0011] The first raw material comprises a boron-phosphorus-aluminum composition, a molecular sieve, clay, and a binder.

[0012] The boron-phosphorus-aluminum composition is a mixture of AlPO4 and B, P, and Al, and is subjected to calcination treatment during preparation.

[0013] According to the preparation method of the present application, the first raw material can further comprise pseudo-boehmite.

[0014] According to the preparation method of the present application, preferably, the boron-phosphorus-aluminum composition is prepared by reacting an aluminum compound, phosphoric acid, and a boron compound and calcining at 400-700°C.

[0015] The boron compound is added in a content of 2wt%-6wt% of boron in the total mass of the boron-phosphorus-aluminum composition, more preferably 2wt%-4wt%.

[0016] The aluminum compound and the phosphoric acid are added in a molar ratio of Al:P of (0.5-2.0):1, more preferably (0.9-1.5):1.

[0017] According to the preparation method of the present application, preferably, the boron-phosphorus-aluminum composition is prepared by Method I or Method II.

[0018] Method I: The aluminum compound is added to water, and then phosphoric acid is added dropwise; the boron compound is added and stirred to obtain a sol containing boron, phosphorus, and aluminum.

[0019] The sol containing boron, phosphorus, and aluminum is dried and calcined at 400-700°C for 1h-4h to obtain the boron-phosphorus-aluminum composition.

[0020] Method II: The aluminum compound is added to water, and then phosphoric acid is added dropwise to obtain a sol containing phosphorus and aluminum; the sol containing phosphorus and aluminum is dried to obtain an intermediate product;

[0021] The boron compound is dissolved in water, loaded in the intermediate product by impregnation, dried, and calcined at 400-700°C for 1-4h to obtain the boron phosphorus aluminum composition.

[0022] In the preparation of the catalytic cracking catalyst, the solid content of the system is preferably 10wt%-45wt% when the first raw material is mixed with water and beaten. The calcination temperature of the catalytic cracking catalyst is preferably 400-800°C, and the time is preferably 0.5-3h. The drying temperature is preferably 100-150°C, and the time is preferably 8-24h. The washing is performed by water washing.

[0023] In the preparation of the boron phosphorus aluminum composition, a mesoporous structure can be formed after calcination, and the boron is fixed in the pores of the composition and is not easy to migrate to the surface of the molecular sieve in the preparation of the catalyst, thereby preventing the destruction of the framework structure of the molecular sieve and maintaining the relatively high activity stability of the catalyst. In the first method and the second method, the calcination temperature is preferably 400-700°C, and the time is preferably 1-4h. In addition, the drying temperature is 80-120°C, and the time is 5-24h.

[0024] In the preparation of the boron phosphorus aluminum composition, in the first method and the second method, the stirring state can be maintained for a period of time, for example 1-5h, after the dropwise addition of phosphoric acid is completed. In the first method, the stirring is preferably continued for 0.5-3h after the boron compound is added.

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

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

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

[0028] In the preparation of the catalytic cracking catalyst, preferably, the specific preparation process of the catalytic cracking catalyst includes:

[0029] The second raw material is added into water and mixed uniformly, and then the binder is added after aging to form a catalyst matrix slurry; the second raw material is part of the components in the first raw material, including the boron-phosphorus-aluminum composition and clay, or the second raw material includes the boron-phosphorus-aluminum composition, clay and pseudo-boehmite;

[0030] The molecular sieve is added into water and sheared, and then the catalyst matrix slurry is added to be beaten, and then the catalyst matrix slurry is formed by spray forming, calcination, washing and drying to obtain the catalytic cracking catalyst.

[0031] More preferably, the temperature of the aging is 40-90℃, and further preferably 75℃, and the aging time is 1-5h, and further preferably 1h.

[0032] In the preparation process of the catalytic cracking catalyst, preferably, the dry basis of the boron-phosphorus-aluminum composition accounts for 5wt%-25wt% of the mass of the catalytic cracking catalyst.

[0033] In the preparation process of the catalytic cracking catalyst, preferably, in the obtained catalytic cracking catalyst, the content of the molecular sieve is 20wt%-50wt% based on the dry basis of the corresponding raw material oxide, the content of the boron-phosphorus-aluminum composition is 5wt%-25wt%, the content of the clay is 19wt%-55wt%, the content of the pseudo-boehmite is 0-13wt%, and the content of the binder is 8wt%-15wt%.

[0034] In the preparation process of the catalytic cracking catalyst, preferably, the clay is selected from one or more combinations of kaolin, halloysite, montmorillonite and attapulgite.

[0035] In the preparation process of the catalytic cracking catalyst, preferably, the binder is selected from one or more combinations of aluminum sol, silicon sol or colloidal aluminum oxide or silicon oxide material.

[0036] The second aspect of the present application provides a catalytic cracking catalyst resistant to heavy metal nickel pollution, which is prepared by the preparation method provided in the first aspect.

[0037] In the catalytic cracking catalyst resistant to heavy metal nickel pollution, the content of the molecular sieve is 20wt%-50wt% based on the dry basis of the corresponding raw material oxide.

[0038] The anti-heavy metal nickel pollution catalytic cracking catalyst according to the present application, preferably, the content of the clay in the anti-heavy metal nickel pollution catalytic cracking catalyst is 19wt% to 55wt% in terms of dry base oxide corresponding to the raw material.

[0039] The anti-heavy metal nickel pollution catalytic cracking catalyst according to the present application, preferably, the content of the clay in the anti-heavy metal nickel pollution catalytic cracking catalyst is 19wt% to 55wt% in terms of dry base oxide corresponding to the raw material.

[0040] The anti-heavy metal nickel pollution catalytic cracking catalyst according to the present application, preferably, the content of the clay in the anti-heavy metal nickel pollution catalytic cracking catalyst is 19wt% to 55wt% in terms of dry base oxide corresponding to the raw material.

[0041] The anti-heavy metal nickel pollution catalytic cracking catalyst according to the present application, preferably, the content of the clay in the anti-heavy metal nickel pollution catalytic cracking catalyst is 19wt% to 55wt% in terms of dry base oxide corresponding to the raw material.

[0042] The anti-heavy metal nickel pollution catalytic cracking catalyst according to the present application, preferably, the content of the clay in the anti-heavy metal nickel pollution catalytic cracking catalyst is 19wt% to 55wt% in terms of dry base oxide corresponding to the raw material.

[0043] In the preparation process of the boron phosphorus aluminum composition, mesoporous structure is finally formed by calcination, and boron is fixed in the pore of the composition and is not easy to migrate to the surface of the molecular sieve in the preparation process of the catalyst, so as to damage the skeleton structure of the molecular sieve and make the catalyst maintain relatively high activity stability. DETAILED DESCRIPTION

[0044] In order to more clearly illustrate the present application, the present application will be further described below in combination with preferred embodiments. It should be understood by those skilled in the art that the specific description below is illustrative rather than limiting, and the protection scope of the present application should not be limited thereby.

[0045] All numerical designations (e.g., temperature, time, amount, and weight, etc., including each range thereof) in the present application generally are approximations. Unless otherwise indicated, the numerical designations are approximations. Although the terms "about" can be readily understood by those skilled in the art, it is to be understood that the terms "comprising" and "including" are to be construed as specifying the presence of stated features or components rather than precluding the presence or addition of further features or components.

[0046] The raw materials and properties used in the following examples are as follows:

[0047] Kaolin, silica sol (solid content 40wt%), aluminum sol (solid content 18wt%), various molecular sieves, pseudo-boehmite (dry basis excluding the part after ignition, its molecular weight is 101.96), and hydrochloric acid (30wt%) are all industrial grade; nickel nitrate, boric acid, boric anhydride, aluminum nitrate, aluminum chloride, ammonium metavanadate, oxalic acid, and phosphoric acid 85wt% are all analytically pure.

[0048] Catalyst micro-reaction activity evaluation method: The micro-reaction activity evaluation device developed by Beijing Hui Er San Ji Green Chemical Technology Co., Ltd. was used for evaluation. The raw oil used was 3 million tons / year catalyst material from Lanzhou Petrochemical Company. The properties of the raw oil are shown in Table 1. The catalyst was aged at 800°C for 17h with 100% steam before evaluation.

[0049] Catalyst reaction performance evaluation method (ACE):

[0050] The catalyst was contaminated with heavy metals before evaluation. The method of heavy metal contamination was simulated by the nickel content in industry: the aqueous solution of nickel nitrate (12000ppm Ni based on the dry catalyst) was impregnated into the catalyst, dried at 120°C, and calcined at 550°C for 4h. The reaction performance was evaluated using the ACE device. The raw oil used was 3 million tons / year catalyst material from Lanzhou Petrochemical Company. The properties of the raw oil are shown in Table 1. The catalyst was aged at 800°C for 10h with 100% steam before evaluation.

[0051] Table 1 Properties of raw oil

[0052]

[0053] Preparation of boron-phosphorus-aluminum composition:

[0054] Composition 1

[0055] 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, forming a transparent homogeneous sol. Then 85.68g of boric acid (B: 1.4mol) was added, and stirring was continued for 0.5h. The sol was dried in an oven at 80°C for 24h and calcined at 700°C for 1h to obtain composition 1.

[0056] Composition 2

[0057] 1019.60 g of dry pseudo-boehmite (Al: 20 mol) was dispersed in 3 L of water with stirring, stirring was continued for 0.5 h, 1400.00 g of 70 wt% phosphoric acid (P: 10 mol) was added dropwise under stirring, a homogeneous sol was formed, stirring was continued for 1 h, then 219.30 g of boric acid anhydride (B: 6.3 mol) was added, stirring was continued for 1 h, the sol was dried in an oven at 120 °C for 5 h, and calcined at 500 °C for 2 h to obtain composition 2.

[0058] Composition 3

[0059] 1333.40 g of aluminum chloride (Al: 10 mol) was dissolved in 1 L of water with stirring, 6533.33 g of 30 wt% phosphoric acid (P: 20 mol) was added dropwise under stirring, a homogeneous sol was formed, stirring was continued for 2 h, then 653.18 g of ammonium borate (B: 10.54 mol) was added, stirring was continued for 1 h, the sol was dried in an oven at 90 °C for 10 h, and calcined at 450 °C for 3 h to obtain composition 3.

[0060] Composition 4

[0061] 2129.96 g of aluminum nitrate (Al: 10 mol) was added to 2 L of water under stirring until dissolved, 1633.33 g of 40 wt% phosphoric acid (P: 6.7 mol) was added dropwise to the dissolved aluminum nitrate, a homogeneous sol was formed, then 281.05 g of ammonium fluoroborate (B: 2.7 mol) was added, stirring was continued for 0.5 h, the sol was dried in an oven at 110 °C for 15 h, and calcined at 400 °C for 4 h to obtain composition 4.

[0062] Composition 5

[0063] 1333.40 g of aluminum chloride (Al: 10 mol) was dissolved in 1 L of water with stirring, 6533.33 g of 30 wt% phosphoric acid (P: 20 mol) was added dropwise under stirring, a homogeneous sol was formed, stirring was continued for 2 h, the sol was dried in an oven at 120 °C for 10 h, and ground into powder.

[0064] 217.28 g of boric acid (B: 3.51 mol) was dissolved in 500 mL of water, added to the above powder and soaked for 1 h, dried at 120 °C for 5 h, and calcined at 450 °C for 3 h to obtain composition 5.

[0065] Comparative composition 1

[0066] 1019.60 g dry based pseudo-boehmite (Al: 20 mol) was dispersed in 3 L water with stirring, the stirring was continued for 0.5 h, 1960.00 g 50 wt% phosphoric acid (P: 10 mol) was added dropwise under stirring, the stirring was continued for 1 h for aging, then 274.11 g boric acid (B: 7.9 mol) was added, the stirring was continued for 1 h, the sol was dried in an oven at 100 °C for 12 h, to obtain comparative composition 1.

[0067] Comparative composition 2

[0068] 2129.96 g aluminum nitrate (Al: 10 mol) was added into 3 L water under stirring until dissolved, then 61.83 g boric acid (B: 1 mol) was added, the stirring was continued for 0.5 h, the mixture was dried in an oven at 80 °C for 24 h, and calcined at 700 °C for 1 h, to obtain comparative composition 2.

[0069] Comparative composition 3

[0070] 1019.60 g dry based pseudo-boehmite (Al: 20 mol) was dispersed in 3 L water with stirring, the stirring was continued for 0.5 h, 1400.00 g 70 wt% phosphoric acid (P: 10 mol) was added dropwise under stirring, to form a homogeneous sol, the stirring was continued for 1 h, the sol was dried in an oven at 120 °C for 5 h, and calcined at 500 °C for 2 h, to obtain comparative composition 3.

[0071] The compositions and corresponding partial preparation conditions of compositions 1-5 and comparative compositions 1-3 are shown in Table 2.

[0072] Table 2 Compositions and preparation conditions of compositions 1-5 and comparative compositions 1-3

[0073]

[0074] Example 1

[0075] This example uses composition 1 to prepare a catalytic cracking catalyst S1, including the following steps:

[0076] In a reaction kettle with water bath heating, 2.5 L water, 870 g kaolin, 150 g pseudo-boehmite, 600 g composition 1 were added, then 90 g hydrochloric acid was slowly added and mixed uniformly, after stirring for 1 hour, it was aged at 75 °C for 1 h, then 1666 g aluminum sol was added to form a catalyst matrix slurry; 2 L water was added to the beater, 1080 g RDSY molecular sieve was added, after passing through a high-speed shearing machine for 20 min, it was added to the catalyst matrix slurry, after beating for 1 h, it was formed by spray molding, the obtained microspheres were calcined at 500 °C for 1 hour, washed with water, and dried in an oven at 120 °C for 8 h, to obtain catalyst S1.

[0077] Example 2

[0078] This example uses composition 2 to prepare catalytic cracking catalyst S2, including the following steps:

[0079] In a reaction kettle with water bath heating, 2L water, 660g erolite, 450g composition 2 are mixed uniformly, after stirring for 1 hour, aging at 75℃ for 1h, then 2166g aluminum sol is added to form a catalyst matrix slurry; 1.7L water is added to the beater tank, 1260g RDSY+240g ZSM-5 molecular sieve is added, after passing through the high-speed shearing machine for 20min, it is added to the catalyst matrix slurry, after beating for 1h, it is formed by spray molding, the obtained microspheres are calcined at 400℃ for 3 hours, washed with water, and dried in an oven at 100℃ for 20h to obtain catalyst S2.

[0080] Example 3

[0081] This example uses composition 3 to prepare catalytic cracking catalyst S3, including the following steps:

[0082] In a reaction kettle with water bath heating, 3.5L water, 1140g montmorillonite, 150g composition 3, 390g pseudo-boehmite are mixed uniformly, 190g hydrochloric acid is added dropwise, after stirring for 1 hour, aging at 75℃ for 1h, then 1333g aluminum sol is added to form a catalyst matrix slurry; 4L water is added to the beater tank, 980g RDSY+100g REY molecular sieve is added, after passing through the high-speed shearing machine for 20min, it is added to the catalyst matrix slurry, after beating for 1h, it is formed by spray molding, the obtained microspheres are calcined at 800℃ for 0.5 hours, washed with water, and dried in an oven at 150℃ for 8h to obtain catalyst S3.

[0083] Example 4

[0084] This example uses composition 4 to prepare catalytic cracking catalyst S4, including the following steps:

[0085] In a reaction kettle with water bath heating, 2.5L water, 1620g attapulgite, 300g composition 4, 180g pseudo-boehmite are mixed uniformly, 90g hydrochloric acid is added dropwise, after stirring for 1 hour, aging at 75℃ for 1h, then 1333g aluminum sol is added to form a catalyst matrix slurry; 3.5L water is added to the beater tank, 600g beta molecular sieve is added, after passing through the high-speed shearing machine for 20min, it is added to the catalyst matrix slurry, after beating for 1h, it is formed by spray molding, the obtained microspheres are calcined at 500℃ for 1 hour, washed with water, and dried in an oven at 120℃ for 15h to obtain catalyst S4.

[0086] Example 5

[0087] This example uses composition 5 to prepare catalytic cracking catalyst S5, including the following steps:

[0088] In a reactor with water bath heating, 3.5 L of water, 840 g of kaolin, 450 g of composition 5, 240 g of pseudo-boehmite were mixed uniformly, 120 g of hydrochloric acid was added dropwise, stirred for 1 hour, then aged at 75°C for 1 h, then 1125 g of silica sol was added to form a catalyst matrix slurry; 3.0 L of water was added to the beater tank, 800 g of RDSY + 280 g of REY molecular sieve was added, after passing through the high-speed shearing machine for 20 min, it was added to the catalyst matrix slurry, and after beating for 1 h, it was formed by spraying. The obtained microspheres were calcined at 500°C for 1 hour, washed with water, and dried in an oven at 100°C for 24 h to obtain catalyst S5.

[0089] Example 6

[0090] This example uses composition 2 to prepare a catalytic cracking catalyst S6, including the following steps:

[0091] In a reactor with water bath heating, 4 L of water, 1050 g of kaolin, 4240 g of composition 2, 270 g of pseudo-boehmite were mixed uniformly, 130 g of hydrochloric acid was added dropwise, stirred for 1 hour, then aged at 75°C for 1 h, then 900 g of silica sol was added to form a catalyst matrix slurry; 4 L of water was added to the beater tank, 1080 g of RDSY molecular sieve was added, after passing through the high-speed shearing machine for 20 min, it was added to the catalyst matrix slurry, and after beating for 1 h, it was formed by spraying. The obtained microspheres were calcined at 500°C for 1 hour, washed with water, and dried in an oven at 120°C for 18 h to obtain catalyst S6.

[0092] Comparative Example 1

[0093] This comparative example prepares a catalytic cracking catalyst D1, wherein a boron phosphorus aluminum composition is not used, including the following steps:

[0094] In a reactor with water bath heating, 2.5 L of water, 1470 g of kaolin, 150 g of pseudo-boehmite were mixed uniformly, then 90 g of hydrochloric acid was slowly added, stirred for 1 hour, then aged at 75°C for 1 h, then 1666 g of aluminum sol was added to form a catalyst matrix slurry; 2 L of water was added to the beater tank, 1080 g of RDSY molecular sieve was added, after passing through the high-speed shearing machine for 20 min, it was added to the catalyst matrix slurry, and after beating for 1 h, it was formed by spraying. The obtained microspheres were calcined at 500°C for 1 hour, washed with water, and dried in an oven at 120°C for 8 h to obtain catalyst D1.

[0095] Comparative Example 2

[0096] This comparative example prepares a catalytic cracking catalyst D2, wherein boric acid is used instead of a boron phosphorus aluminum composition, including the following steps:

[0097] In a reactor with water bath heating, 2.5 L of water, 1470 g of kaolin, 150 g of pseudo-boehmite, 422 g of boric acid were mixed homogeneously, then 90 g of hydrochloric acid was slowly added, stirred for 1 hour, then aged at 75°C for 1 h, then 1666 g of aluminum sol was added to form a catalyst matrix slurry; 2 L of water was added to the beater tank, 1080 g of RDSY molecular sieve was added, and after 20 min of high-speed shearing, it was added to the catalyst matrix slurry, and after beating for 1 h, it was formed by spraying. The obtained microspheres were calcined at 500°C for 1 hour, washed with water, dried in an oven at 100°C for 24 h, and catalyst D2 was obtained.

[0098] Comparative Example 3

[0099] This comparative example prepared a catalytic cracking catalyst D3 using comparative composition 1, including the following steps:

[0100] In a reactor with water bath heating, 3.5 L of water, 840 g of kaolin, 450 g of comparative composition 1, 240 g of pseudo-boehmite were mixed homogeneously, 120 g of hydrochloric acid was added dropwise, stirred for 1 hour, then aged at 75°C for 1 h, then 1125 g of silica sol was added to form a catalyst matrix slurry; 3.0 L of water was added to the beater tank, 1080 g of RDSY molecular sieve was added, and after 20 min of high-speed shearing, it was added to the catalyst matrix slurry, and after beating for 1 h, it was formed by spraying. The obtained microspheres were calcined at 500°C for 1 hour, washed with water, dried in an oven at 150°C for 8 h, and catalyst D3 was obtained.

[0101] Comparative Example 4

[0102] This comparative example prepared a catalytic cracking catalyst D4, in which a sol containing boron, phosphorus, and aluminum was used instead of the boron-phosphorus-aluminum composition of the present application, including the following steps:

[0103] 773.37 g of aluminum chloride was dissolved in 500 L of water with stirring, 1421 g of 80 wt% phosphoric acid was added dropwise under stirring, 49 g of boric acid was added dropwise, a homogeneous sol was formed, and stirring was continued for 2 h to obtain sol A.

[0104] In a reactor with water bath heating, 2.0 L of water, 840 g of kaolin, 240 g of pseudo-boehmite were mixed homogeneously, 120 g of hydrochloric acid was added dropwise, and the above obtained sol A was added, stirred for 1 hour, then aged at 75°C for 1 h, then 1125 g of silica sol was added to form a catalyst matrix slurry; 3.0 L of water was added to the beater tank, 800 g of RDSY+280 g of REY molecular sieve was added, and after 20 min of high-speed shearing, it was added to the catalyst matrix slurry, and after beating for 1 h, it was formed by spraying. The obtained microspheres were calcined at 800°C for 0.5 hour, dried in an oven at 120°C for 20 h, and catalyst D4 was obtained.

[0105] Comparative Example 5

[0106] This comparative example prepared catalytic cracking catalyst D5 using comparative composition 2, including the following steps:

[0107] In a reactor with water bath heating, 3.5 L of water, 840 g of kaolin, 450 g of comparative composition 2, 240 g of pseudo-boehmite were mixed uniformly, 120 g of hydrochloric acid was added dropwise, stirred for 1 hour, then aged at 75°C for 1 h, then 1125 g of silica sol was added to form a catalyst matrix slurry; 3.0 L of water was added to the beater tank, 800 g of RDSY + 280 g of REY molecular sieve was added, after passing through the high-speed shearing machine for 20 min, the catalyst matrix slurry was added, and after beating for 1 h, the obtained microspheres were spray formed, and then the obtained microspheres were calcined at 500°C for 1 hour, washed with water, and dried in an oven at 120°C for 8 h to obtain catalyst D5.

[0108] Comparative Example 6

[0109] This comparative example prepared catalytic cracking catalyst D6 using comparative composition 3, including the following steps:

[0110] In a reactor with water bath heating, 3.5 L of water, 840 g of kaolin, 450 g of comparative composition 2, 240 g of pseudo-boehmite were mixed uniformly, 120 g of hydrochloric acid was added dropwise, stirred for 1 hour, then aged at 75°C for 1 h, then 1125 g of silica sol was added to form a catalyst matrix slurry; 3.0 L of water was added to the beater tank, 800 g of RDSY + 280 g of REY molecular sieve was added, after passing through the high-speed shearing machine for 20 min, the catalyst matrix slurry was added, and after beating for 1 h, the obtained microspheres were spray formed, and then the obtained microspheres were calcined at 500°C for 1 hour, washed with water, and dried in an oven at 120°C for 8 h to obtain catalyst D5.

[0111] Comparative Example 7

[0112] This comparative example prepared catalytic cracking catalyst D7, wherein boric acid, phosphoric acid (both 1 wt% of the catalyst dry basis) were used instead of boron phosphorus aluminum composition, including the following steps:

[0113] In a reactor with water bath heating, 2.5 L of water, 1470 g of kaolin, 150 g of pseudo-boehmite were mixed uniformly, then 90 g of hydrochloric acid, 422 g of boric acid were slowly added, stirred for 1 hour, then aged at 75°C for 1 h, then 1666 g of aluminum sol was added, 358 g of 85wt% phosphoric acid was added to form a catalyst matrix slurry; 2 L of water was added to the beater tank, 800 g of RDSY + 280 g of REY molecular sieve was added, after passing through the high-speed shearing machine for 20 min, the catalyst matrix slurry was added, and after beating for 1 h, the obtained microspheres were spray formed, and then the obtained microspheres were calcined at 500°C for 1 hour, washed with water, and dried in an oven at 100°C for 24 h to obtain catalyst D2.

[0114] The compositions of each component of the above catalysts S1-S6 and below D1-D7 are shown in Table 3, the activity data are shown in Table 4, and the ACE evaluation results of each catalyst pollution sample (polluted by 12000 ppm nickel) are shown in Table 5.

[0115] Table 3 Composition of each component of the catalysts obtained in the examples and comparative examples (dry basis, calculated as oxides)

[0116]

[0117] Table 4 Catalyst activity (MAT, 800℃x17h)

[0118] Catalyst No. S1 S2 S3 S4 S5 S6 D1 D2 D3 D4 D5 D6 D7 Catalyst activity 62 63 62 63 61 63 63 57 59 58 57 62 59

[0119] As can be seen from Table 4, the catalysts S1-S6 of the examples still have relatively high activity after water vapor aging at 800℃x17h, while the activity of the catalysts D2, D3 and D4 of the comparative examples decreases significantly, indicating that the addition method of boron (B) has an impact on the structure of the molecular sieve. The presence of AlPO4 in the boron-phosphorus-aluminum composition of the present application can effectively inhibit the dealumination of the molecular sieve, offset the poisoning effect of the addition of B on the catalyst, and at the same time, during the preparation of the boron-phosphorus-aluminum composition, a mesoporous structure is formed by calcination, and the boron is fixed in the pores of the composition and is not easy to migrate to the surface of the molecular sieve during the preparation of the catalyst, thereby destroying the framework structure of the molecular sieve, so that the catalysts S1-S6 can still maintain relatively high activity stability after water vapor aging at 800℃x17h. Catalyst D2 uses boric acid instead of the boron-phosphorus-aluminum composition, catalyst D3 uses the comparative composition 1 without calcination, catalyst D4 uses a sol containing boron, phosphorus and aluminum instead of the boron-phosphorus-aluminum composition of the present application, D5 uses a phosphorus-free composition 2, and D7 uses a form of directly adding phosphoric acid and boric acid, all of which show a significant decrease in activity. Catalyst D1 does not add the composition or other B substitutes, serving as a blank control. D6 uses a boron-free comparative composition 3.

[0120] Table 5 ACE evaluation results of each catalyst pollution sample

[0121]

[0122] From Table 5, it can be seen that, after the catalyst is contaminated by 12000 ppm nickel, the conversion rate of the catalyst sample of the example is relatively high, and the H2 / CH4 ratio is relatively low, relative to the catalysts D1, D6 of the comparative examples, which indicates that the addition of the boron phosphorus aluminum composition of the application can fix the nickel metal, thereby inhibiting the dehydrogenation effect generated by the nickel, so that the H2 / CH4 ratio is relatively low, and the catalyst has certain nickel resistance. Relative to the comparative examples D2, D3, D4, D5, D6, D7, the examples S1-S2 have relatively high conversion rates, which indicates that the addition of the boron phosphorus aluminum composition in the manner of the examples has the least negative impact on the catalyst.

[0123] Obviously, the above examples of the application are only examples for clearly illustrating the application, and are not limitations on the embodiments of the application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art, and it is impossible to enumerate all the embodiments here. Any obvious changes or variations derived from the technical solutions of the application still fall within the protection scope of the application.

Claims

1. A method for preparing a catalytic cracking catalyst resistant to heavy metal nickel contamination, wherein, The preparation method includes the following steps: The first raw material is mixed with water and pulped, then spray-molded, calcined, washed and dried to obtain the catalytic cracking catalyst. The first raw material includes a boron-phosphorus-aluminum composition, molecular sieves, clay, and binder; The boron-phosphorus-aluminum composition is a mixture of AlPO4 and B, P, and Al, and is prepared by reacting aluminum compounds, phosphoric acid, and boron compounds and calcining at 400-700°C. The boron compound is added at a boron content of 2 wt% to 6 wt% of the total mass of the boron-phosphorus-aluminum composition. The aluminum compound and phosphoric acid were added at an Al:P molar ratio of (0.5~2.0):1; The boron-phosphorus-aluminum 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 and stir to obtain a sol containing boron, phosphorus and aluminum; The sol containing boron, phosphorus, and aluminum is dried and calcined to obtain the boron-phosphorus-aluminum composition; Method 2: Add aluminum compound to water, then add phosphoric acid dropwise to obtain a sol containing phosphorus and aluminum; dry the sol containing phosphorus and aluminum 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 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 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 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.

6. 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 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.

7. 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.

8. 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, are as follows: the content of the molecular sieve is 20wt%~50wt%, the content of the boron-phosphorus-aluminum composition is 5wt%~25wt%, the content of the clay is 19wt%~55wt%, 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%.

9. 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.

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

11. 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.

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

13. A catalytic cracking catalyst resistant to heavy metal nickel contamination, prepared by the preparation method according to any one of claims 1-12.

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