Iron-pollution-resistant catalytic cracking catalyst and preparation method thereof

Abstract

The invention provides an iron-pollution-resistant catalytic cracking catalyst and a preparation method thereof, and the iron-pollution-resistant catalytic cracking catalyst comprises the following raw materials: a mesoporous and macroporous material, a zinc-aluminum composite material and a molecular sieve, wherein the mesopore and macropore material comprises kaolin and first zinc salt loaded in pores of the kaolin; the zinc-aluminum composite material is obtained by performing solid-phase ball milling on pseudo-boehmite and second zinc salt. The catalytic cracking catalyst provided by the invention has abundant mesopore and macropore structures and excellent iron resistance.

Description

Technical Field

[0001] This invention relates to the field of catalytic materials, and more particularly to an iron-resistant catalytic cracking catalyst and its preparation method. Background Technology

[0002] With the increasing weight and quality of crude oil worldwide, blending heavy oil and residue oil into catalytic cracking has become a means for refineries in various countries to improve economic efficiency. Compared with conventional FCC feedstocks (such as AGO and VGO), the heavy metal content in residue oil or heavy oil is significantly higher, which seriously contaminates FCC catalysts. Iron poisoning has occurred in the catalytic units of some refineries at home and abroad. Therefore, developing an iron capture technology based on a medium- or macroporous matrix material and an iron-resistant catalyst has become a common concern for technical personnel.

[0003] Patent CN1209442C discloses a catalytic cracking catalyst and its preparation method. The catalyst contains 5-60% macroporous and mesoporous alumina, 15-40% zeolite, 10-20% binder, and 10-65% clay. The preparation method of the catalytic cracking catalyst is to mix the zeolite with macroporous and mesoporous alumina, binder precursor, and clay evenly, and then obtain the catalyst through spraying, calcination, washing, and drying. The catalyst has enhanced heavy oil conversion capacity, but its resistance to metal contamination needs to be improved.

[0004] Patent CN101745417B discloses a catalytic cracking catalyst containing alumina with a stepped pore distribution, a binder, and a Y-type molecular sieve, with or without clay. The alumina with a stepped pore distribution consists of 10-90 wt% macroporous alumina and 10-90 wt% microporous alumina. This catalyst has high pore volume, good wear resistance, and maintains a stepped pore distribution after hydrothermal aging. When used in catalytic cracking, it exhibits strong heavy oil cracking capacity, high light oil yield, and good coke selectivity. However, the liquid yield of this catalyst is not high, and its resistance to heavy metal contamination is weak.

[0005] Patent CN106179458A discloses a catalytic cracking catalyst containing cracking active components, mesoporous active materials, clay, and a binder. The mesoporous active materials have a pseudo-boehmite structure. Through the combination of specific cracking active components, specific mesoporous active materials, clay, and binder, the mesoporous content in the catalyst is increased, which is beneficial for the diffusion and cracking of heavy oil macromolecules, but its anti-iron effect is limited. Summary of the Invention

[0006] This invention provides an iron-resistant catalytic cracking catalyst that, when used to catalyze iron-containing crude oil, can reduce the toxicity of iron, thereby increasing the yield of diesel and gasoline.

[0007] The present invention also provides a method for preparing the above-mentioned iron-resistant catalytic cracking catalyst, which can improve the pore structure of the catalyst and increase its iron resistance.

[0008] In a first aspect, the present invention provides an iron-resistant catalytic cracking catalyst, the raw materials of which include: mesoporous and macroporous materials, zinc-aluminum composite materials and molecular sieves; wherein, the mesoporous and macroporous materials include kaolin and a first zinc salt loaded in the pores of the kaolin; the zinc-aluminum composite material is obtained by solid-phase ball milling of boehmite and a second zinc salt.

[0009] Furthermore, the mass ratio of the zinc-aluminum composite material, the mesoporous material, and the molecular sieve is 40-150:40-180:120-185.

[0010] Furthermore, the mesopore volume of the mesopore material is 0.50-0.65 cm³. 3 / g.

[0011] Furthermore, in the zinc-aluminum composite material, the second zinc salt is calculated as zinc oxide, and the mass ratio of zinc oxide to boehmite is 0.2-0.8:1 based on dry weight.

[0012] And / or, the first zinc salt, calculated as zinc oxide, has a mass ratio of kaolin to zinc oxide of 1-10:1.

[0013] Furthermore, the molecules are screened from one or more of HY, REY, USY, REHY, REUSY, and HZSM-5.

[0014] Furthermore, the mesoporous material is prepared by a method comprising the following process:

[0015] Kaolin is calcined once to obtain dry kaolin. The dry kaolin is then mixed with an alkaline solution and subjected to alkali treatment to obtain pore-enlarged kaolin.

[0016] A mixture of kaolin, macroporous template agent, and first binder, which has undergone pore-expanding treatment, is subjected to a secondary calcination treatment. The first zinc salt is impregnated and adhered to at least a portion of the pores of the kaolin after the secondary calcination treatment to obtain the medium- and macroporous material.

[0017] Furthermore, the temperature of the first calcination treatment is 920-1000℃, and the time is 1-3 hours;

[0018] The secondary roasting process is carried out at a temperature of 400-600℃ for 1-3 hours.

[0019] Furthermore, the macroporous template agent is at least one of glucose, polystyrene microspheres, and polymethyl methacrylate microspheres.

[0020] Secondly, the present invention provides a method for preparing the above-mentioned iron-resistant catalytic cracking catalyst, comprising the following steps:

[0021] Molecular sieves are added to a mixed system comprising the aforementioned macroporous material, a second binder, and a zinc-aluminum composite material. The mixture is then subjected to a series of processes including mixing and pulping, spray drying, and calcination to obtain the catalytic cracking catalyst.

[0022] Furthermore, the temperature of the three calcination treatments is 350-650℃, and the time is 1-4 hours.

[0023] The catalytic cracking catalyst for iron contamination provided by this invention has zinc salt supported in the pores of kaolin. During the preparation of the catalytic cracking catalyst, the zinc salt, through calcination, forms zinc oxide particles that can form high-melting-point substances with iron, thereby achieving an iron-fixing effect. In addition, this invention also prepares a zinc-aluminum composite material by solid-phase ball milling. The addition of this material can synergistically form more high-melting-point substances with iron in the catalyst system with zinc oxide, thereby achieving a better iron-fixing effect, reducing the generation of low-temperature iron eutectic, and reducing the catalyst surface coverage caused by iron contamination from the source. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below. The specific embodiments listed below are merely descriptions of the principles and features of the present invention, and the examples are only for explaining the present invention and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In this application, the term "and / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone. A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0026] In this application, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0027] In this application, the term "micropores" refers to pores with a diameter < 2 nm; the term "mesopores" refers to pores with a diameter in the range of 2-50 nm; the term "macropores" refers to pores with a diameter > 50 nm; and the term "meso-macropore material" refers to a material that includes both mesopores and macropores.

[0028] In detail, in a first aspect, the present invention provides an iron-resistant catalytic cracking catalyst, the raw materials of which include: mesoporous and macroporous materials, zinc-aluminum composite materials and molecular sieves; wherein, the mesoporous and macroporous materials include kaolin and a first zinc salt loaded in the pores of the kaolin; the zinc-aluminum composite material is obtained by solid-phase ball milling of boehmite and a second zinc salt.

[0029] In this invention, zinc salts are loaded into the pores of kaolin. During the preparation of the catalytic cracking catalyst, the zinc oxide particles formed by calcination of the zinc salts can form high-melting-point substances with iron to achieve an iron-fixing effect. In addition, this invention also prepares a zinc-aluminum composite material by solid-phase ball milling. The addition of this material can synergistically form more high-melting-point substances with iron in the catalyst system with zinc oxide to achieve a better iron-fixing effect. The addition of the zinc-aluminum composite material can further increase the melting point of the catalyst-iron eutectic and reduce the generation of low-temperature iron eutectic, thereby reducing the catalyst surface coverage caused by iron contamination from the source.

[0030] For example, the ball milling speed for the solid-phase ball milling treatment is 500-1000 r / min. The ball milling speed affects the formation of the zinc-aluminum composite material to some extent. If the ball milling speed is below 500 r / min, the reaction between boehmite and zinc salt is insufficient; if the ball milling speed is above 1000 r / min, energy consumption is high, and other side reactions may occur. The invention does not specifically limit the ball milling equipment used; in one specific embodiment, Unionprocess Corporation Qingdao Lianrui Precision Machinery Co., Ltd. is used.

[0031] Furthermore, the solid-phase ball milling treatment time can be 20-60 minutes.

[0032] In one specific embodiment, the mass ratio of the zinc-aluminum composite material, the mesoporous material, and the molecular sieve is 40-150:40-180:120-185. This embodiment, by limiting the mass ratio of the zinc-aluminum composite material, the mesoporous material, and the molecular sieve, can further improve the crude oil conversion rate and the total yield of diesel and gasoline.

[0033] In one specific embodiment, the mesopore volume of the mesopore material is 0.50-0.65 cm³. 3 / g. In this process, zinc salt is loaded into the pores of kaolin, and alumina particles are formed by subsequent calcination. The alumina particles occupy the pore volume of the kaolin. If the proportion of mesoporous and macroporous pores in the material itself is not high, it may affect the normal diffusion of molecules. Therefore, in this embodiment, the mesoporous and macroporous pore volume of the material is kept within a certain range, which can reduce the impact of the alumina particles formed later on molecular diffusion.

[0034] In one specific embodiment, in the zinc-aluminum composite material, the second zinc salt is calculated as zinc oxide, and the mass ratio of zinc oxide to boehmite is 0.2-0.8:1 (dry basis). This ratio of zinc salt and boehmite can achieve a more superior iron-resistant effect.

[0035] And / or, the first zinc salt is calculated as zinc oxide, and the mass ratio of kaolin to zinc oxide is 1-10:1. The main purpose of adding the first zinc salt is to form a high-melting-point substance with iron, thereby achieving the purpose of iron fixation. A mass ratio of kaolin to the first zinc salt within the above range can achieve a good iron-fixing effect while taking cost into account.

[0036] In one specific embodiment, the molecule is screened from one or more of HY, REY, USY, REHY, REUSY, and HZSM-5.

[0037] In one specific embodiment, the mesoporous material is prepared by a method comprising the following processes:

[0038] Kaolin is calcined once to obtain dry kaolin. The dry kaolin is then mixed with an alkaline solution and subjected to alkali treatment to obtain pore-enlarged kaolin.

[0039] A mixture of kaolin, macroporous template agent, and first binder, which has undergone pore-expanding treatment, is subjected to a secondary calcination treatment. A first zinc salt is impregnated and adhered to at least a portion of the pores of the kaolin obtained after the secondary calcination treatment to obtain the medium- and macroporous material.

[0040] In the above preparation method, on the one hand, kaolin can be treated with calcined alkali to form more mesoporous and macroporous structures; the pore-expanding kaolin is then further improved with a macroporous template agent to increase the number of mesoporous and macroporous pores and reduce the blockage of the pores of the macroporous anti-iron material by the iron eutectic. Then, zinc salt is attached to the inner and outer surfaces of the mesoporous and macroporous material through liquid phase impregnation (mainly attached to the pores of the mesoporous and macroporous material). The resulting mesoporous and macroporous material can be calcined to form zinc oxide particles in the pores. Zinc oxide can form a high-melting-point substance with iron to achieve the iron-fixing effect.

[0041] The first zinc salt and the second zinc salt mentioned above may be the same or different. This invention does not impose any particular limitation. Those skilled in the art may use conventional inorganic zinc salts, such as, but not limited to, one or more mixtures selected from zinc chloride, zinc nitrate, and zinc sulfate.

[0042] The present invention does not specifically limit the temperature and time of the above-mentioned alkali treatment. Technicians can adjust them according to the actual situation. In order to save time and ensure the stability of the material pore structure, in a preferred embodiment, the temperature of the alkali treatment is 90-95°C and the treatment time is 1-3 hours.

[0043] It is understood that binders are an essential part of the molding process of medium and large pore materials, playing an important role in helping to mold medium and large pore materials and enhancing their strength. The first binder involved in this invention includes, but is not limited to, one or more of boehmite, silica, SB powder, diatomaceous earth, aluminum hydroxide, aluminum sol, silica-alumina, and alumina.

[0044] Furthermore, the first binder includes boehmite and aluminum sol, wherein the mass ratio of Al2O3 in the aluminum sol to the kaolin is 0.015-0.25:1.

[0045] In one specific embodiment, the dry basis of the kaolin reacts with the OH in the alkaline solution. - The mass ratio is 1-11:1. Among them, the amount of alkali used in alkali treatment affects the pore structure of kaolin. If the amount of alkali is too small, the degree of pore expansion may be insufficient. As the amount of alkali increases, the pore expansion effect improves. However, after reaching a certain level, the pore expansion of kaolin reaches its limit, and the amount of alkali no longer significantly affects the pore structure. The amount of alkali used within the range of the above-described embodiments of the present invention can achieve a better pore expansion effect.

[0046] In one specific embodiment, the temperature of the first calcination treatment is 920-1000℃, and the time is 1-3 hours;

[0047] The secondary roasting process is carried out at a temperature of 400-600℃ for 1-3 hours.

[0048] In one specific embodiment, the macroporous template agent is at least one of glucose, polystyrene microspheres, and polymethyl methacrylate microspheres.

[0049] Furthermore, the polystyrene microspheres or polymethyl methacrylate microspheres have a particle size of 50-100 nm.

[0050] Furthermore, the mass ratio of the macroporous template agent to the kaolin is 0.015-0.06:1. In this embodiment, the polymeric macroporous template agent can further improve the pore structure of the kaolin material, increase the proportion of mesopores in the macroporous material, and thus help to further reduce the blockage of the pores of the macroporous anti-ferrometallic material by the eutectic.

[0051] Secondly, the present invention provides a method for preparing the above-mentioned iron-resistant catalytic cracking catalyst, comprising the following steps:

[0052] Molecular sieves are added to a mixed system comprising the aforementioned macroporous material, a second binder, and a zinc-aluminum composite material. The mixture is then subjected to a series of processes including mixing and pulping, spray drying, and calcination to obtain the catalytic cracking catalyst.

[0053] The second binder and the first binder may be the same or different. The second binder includes, but is not limited to, one or more of the following: boehmite, silica, SB powder, diatomaceous earth, aluminum hydroxide, aluminum sol, silica-alumina, and alumina.

[0054] Furthermore, the temperature of the three calcination treatments is 350-650℃, and the time is 1-4 hours.

[0055] The present invention will be further described below with reference to specific embodiments:

[0056] The present invention is further illustrated below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are all commercially available from the conventional market. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention are within the scope of protection claimed by the present invention.

[0057] The pore volumes of mesopores and macropores were determined by mercury porosimetry (analytical methods can be found in "Modern Catalysis Research Methods", edited by Xin Qin et al., Science Press, 2009).

[0058] Raw material sources: Zinc chloride, zinc nitrate, and zinc sulfate are all analytical grade and produced by Sinopharm Group; kaolin, alkaline solution (NaOH content approximately 14wt%), boehmite, aluminum sol (Al2O3 content approximately 19.4%), polystyrene microspheres, and polymethyl methacrylate microspheres are produced by Lanzhou Petrochemical Company, with a weight average molecular weight in the range of 6000-20000 g / mol.

[0059] Example 1

[0060] This example provides a catalytic cracking catalyst resistant to iron contamination, the raw materials of which include: mesoporous and macroporous materials, zinc-aluminum composite materials and molecular sieves; wherein, the mesoporous and macroporous materials include kaolin and a first zinc salt loaded in the pores of the kaolin; the zinc-aluminum composite material is obtained by solid-phase ball milling of boehmite and a second zinc salt.

[0061] The preparation method of this iron-resistant catalytic cracking catalyst includes the following steps:

[0062] 1) Kaolin was calcined at 950℃ for 1.5 hours, and then 446g of the calcined dry kaolin was mixed with 999g of alkaline solution and treated at 92℃ for 2 hours. After filtration, washing and drying, pore-enlarged kaolin was obtained.

[0063] 2) Mix 265g of dry kaolin, 132g of dry boehmite, 9g of polystyrene microspheres (50nm particle size, 18000g / mol weight average molecular weight), 121g of aluminum sol and deionized water, and calcine at 450℃ for 1.5 hours to obtain medium- and macroporous material C-1.

[0064] 3) Mix 75g of dry boehmite and 42g of zinc chloride evenly, and then mechanically ball-mill for 22 minutes at a speed of 600r / min to obtain zinc-aluminum composite material;

[0065] 4) 171g of zinc chloride is impregnated onto the surface of the above-mentioned mesoporous material using the equal volume impregnation method, and dried at 90°C for 2 hours to obtain the mesoporous material;

[0066] 5) Mix 180g of the above-mentioned macroporous material, 85g of zinc-aluminum composite material, 204g of aluminum sol, 997g of deionized water and 182g of REUSY molecular sieve evenly, spray dry and calcine at 400℃ for 2 hours to obtain catalytic cracking catalyst F1.

[0067] Example 2

[0068] This example provides a catalytic cracking catalyst resistant to iron contamination, the raw materials of which include: mesoporous and macroporous materials, zinc-aluminum composite materials and molecular sieves; wherein, the mesoporous and macroporous materials include kaolin and a first zinc salt loaded in the pores of the kaolin; the zinc-aluminum composite material is obtained by solid-phase ball milling of boehmite and a second zinc salt.

[0069] The preparation method of this iron-resistant catalytic cracking catalyst includes the following steps:

[0070] 1) Kaolin was calcined at 1000℃ for 2 hours, and then the calcined kaolin dry basis 1210 and 4066g of alkaline solution were treated at 96℃ for 2.5 hours. After filtration, washing and drying, pore-enlarged kaolin was obtained.

[0071] 2) Mix 378g of dry kaolin treated with pore expansion, 19g of macroporous template agent polymethyl methacrylate microspheres (particle size 100nm, weight average molecular weight 9000g / mol), 336g of dry boehmite, 175g of aluminum sol and deionized water, and calcine at 550℃ for 2.3 hours to obtain medium and macroporous material C-2;

[0072] 3) Mix 92g of dry boehmite and 91g of zinc sulfate evenly, and then mechanically ball-mill for 21 minutes at a speed of 1000r / min to obtain zinc-aluminum composite material;

[0073] 4) Impregnate 333g of zinc sulfate onto the surface of the above-mentioned mesoporous material using the equal-volume impregnation method, and dry at 120℃ for 3 hours to obtain the mesoporous material;

[0074] 5) Mix 102g of the above-mentioned macroporous material with 115g of aluminum sol, 42g of zinc-aluminum composite material, 680g of deionized water, 58g of HY molecular sieve and 65g of REY molecular sieve, and pulverize evenly. Spray dry and calcine at 650℃ for 1 hour to obtain catalytic cracking catalyst F2.

[0075] Example 3

[0076] This example provides a catalytic cracking catalyst resistant to iron contamination, the raw materials of which include: mesoporous and macroporous materials, zinc-aluminum composite materials and molecular sieves; wherein, the mesoporous and macroporous materials include kaolin and a first zinc salt loaded in the pores of the kaolin; the zinc-aluminum composite material is obtained by solid-phase ball milling of boehmite and a second zinc salt.

[0077] The preparation method of this iron-resistant catalytic cracking catalyst includes the following steps:

[0078] 1) Kaolin was calcined at 980℃ for 3 hours, and then the calcined kaolin dry basis 386 and 648g of alkaline solution were treated at 94℃ for 3.5 hours. After filtration, washing and drying, pore-enlarged kaolin was obtained.

[0079] 2) Mix 332g of pore-expanding kaolin, 13g of macroporous template agent polystyrene microspheres (particle size 80nm, weight average molecular weight 20000g / mol), 23g of boehmite, 119g of alumina sol, and deionized water, and calcine at 500℃ for 1.2 hours to obtain medium- and macroporous material C-3.

[0080] 3) Mix 154g of boehmite dry basis, 30g of zinc chloride, and 36g of zinc sulfate evenly, and then mechanically ball-mill for 23 minutes at a speed of 800r / min to obtain zinc-aluminum composite material.

[0081] 4) Impregnate 15g of zinc chloride and 19g of zinc sulfate onto the surface of the above-mentioned mesoporous material using an equal-volume impregnation method, and dry at 130℃ for 2.5 hours to obtain the mesoporous material;

[0082] 5) Mix 130g of the above-mentioned macroporous material, 55g of zinc-aluminum composite material, 205g of aluminum sol, 990g of deionized water and 160g of REUSY molecular sieve evenly, spray dry, and calcine at 500℃ for 2.5 hours to obtain catalytic cracking catalyst F3.

[0083] Example 4

[0084] The preparation method of the catalytic cracking catalyst provided in this example is basically the same as that in Example 1, except that: in step 1), kaolin is calcined at 920°C for 3 hours to obtain macroporous material C-4 and catalytic cracking catalyst F4.

[0085] Example 5

[0086] The preparation method of the catalytic cracking catalyst provided in this example is basically the same as that in Example 1, except that the polystyrene microspheres have a particle size of 20 nm, resulting in macroporous material C-5 and catalytic cracking catalyst F5.

[0087] Example 6

[0088] The preparation method of the catalytic cracking catalyst provided in this example is basically the same as that in Example 1, except that in step 3), 16g of zinc chloride is impregnated on the surface of the above-mentioned mesoporous material by the equal volume impregnation method to obtain mesoporous material C-6 and catalytic cracking catalyst F6.

[0089] Example 7

[0090] The preparation method of the catalytic cracking catalyst provided in this example is basically the same as that in Example 1, except that the amount of polystyrene microspheres added is 108g, resulting in macroporous material C-7 and catalytic cracking catalyst F7.

[0091] Example 8

[0092] The preparation method of the catalytic cracking catalyst provided in this example is basically the same as that in Example 1, except that the polystyrene microspheres are replaced with glucose to obtain the mesoporous material C-8 and the catalytic cracking catalyst F8.

[0093] Comparative Example 1

[0094] This example provides a catalytic cracking catalyst and its preparation method, which includes the following steps:

[0095] 1) Kaolin was calcined at 950℃ for 1.5 hours, then 446g of dry calcined kaolin was mixed with 999g of alkaline solution and treated at 92℃ for 2 hours. After filtration, washing and drying, pore-enlarged kaolin was obtained.

[0096] 2) 265g of kaolin dry basis treated with pore expansion, 132g of pseudoboehmite dry basis, 9g of polystyrene microspheres (particle size 50nm, weight average molecular weight 18000g / mol), 121g of alumina sol and deionized water were mixed and pulped, and calcined at 450℃ for 1.5 hours to obtain mesoporous and macroporous material D-1.

[0097] 3) Mix 75g of dry boehmite and 42g of zinc chloride evenly, and then mechanically ball-mill for 22 minutes at a speed of 600r / min to obtain zinc-aluminum composite material;

[0098] 4) Mix 180g of the above-mentioned macroporous material D-1, 85g of zinc-aluminum composite material, 204g of aluminum sol, 997g of deionized water and 182g of REUSY molecular sieve evenly, spray dry, and calcine at 400℃ for 2 hours to obtain catalytic cracking catalyst S1.

[0099] Comparative Example 2

[0100] This example provides a method for preparing catalytic cracking catalyst S2, which is basically the same as in Example 2, except that: in step 1), 378g of dry kaolin, 19g of macroporous template agent polymethyl methacrylate microspheres (particle size 100nm, weight average molecular weight 9000g / mol), 336g of dry boehmite, 175g of aluminum sol and deionized water are mixed and slurried, and then calcined at 550℃ for 2.3 hours to obtain mesoporous and macroporous material D-2.

[0101] Comparative Example 3

[0102] This example provides a catalytic cracking catalyst and its preparation method, which includes the following steps:

[0103] 1) Kaolin was calcined at 980℃ for 3 hours, and then the calcined kaolin dry basis 386 and 648g of alkaline solution were treated at 94℃ for 3.5 hours. After filtration, washing and drying, pore-enlarged kaolin was obtained.

[0104] 2) Mix 332 kaolinite with enlarged pores, 23g of boehmite, 119g of alumina sol and deionized water, slurry, and calcine at 500℃ for 1.2 hours to obtain medium- and macroporous material D-3;

[0105] 3) Impregnate 15g of zinc chloride and 19g of zinc sulfate onto the surface of the above-mentioned mesoporous material using an equal-volume impregnation method, and dry at 130℃ for 2.5 hours to obtain the mesoporous material.

[0106] 4) Mix 154g of boehmite dry base, 30g of zinc chloride, and 36g of zinc sulfate evenly, and then mechanically ball-mill for 23 minutes at a speed of 800r / min to obtain zinc-aluminum composite material.

[0107] 5) Mix 130g of the above-mentioned macroporous material, 55g of zinc-aluminum composite material, 205g of aluminum sol, 990g of deionized water and 160g of REUSY molecular sieve evenly, spray dry, and calcine at 500℃ for 2.5 hours to obtain catalytic cracking catalyst S3.

[0108] Table 1 shows the pore volume characterization results of macroporous materials.

[0109]

[0110] As shown in Table 1, compared with Comparison 2-3, the intermediate product prepared in the example - the macroporous material has more macroporous pores, which is more conducive to reducing the blockage of the macroporous anti-iron material pores by the iron eutectic.

[0111] The iron resistance of the catalytic cracking catalyst was tested using the catalytic cracking reaction selectivity evaluation method, which was conducted in a small fixed fluidized bed (FFB) test unit (XGL-2, Luoyang). Before hydrothermal treatment, the catalyst was pre-contaminated with iron to a concentration of 8000 μg / g. The iron-contaminated catalyst was then hydrothermally treated at 800℃ and 100% steam for 4 hours. The hydrothermally treated catalyst was then subjected to reaction selectivity evaluation in a fixed-bed fluidized bed test unit. The feedstock was Lanzhou Petrochemical catalytic feedstock, with specific properties shown in Table 2. The reaction temperature was 500–535℃, and the space velocity was 12–15 h⁻¹. -1 With an oil-to-agent ratio of 5, F1-F8 and S1-S3 were evaluated on a fixed fluidized bed device, and the results are listed in Table 3.

[0112] Table 2 Raw Material Properties

[0113]

[0114]

[0115] Table 3 Evaluation results of catalyst-fixed fluidized bed devices

[0116]

[0117] Note: In the table " Gently gather ” Refers to the total yield of diesel + C5 gasoline.

[0118] As can be seen from the data in Table 3, compared with the comparative example, the catalytic cracking catalyst of the embodiment has better iron resistance through performance evaluation, and the overall performance is higher in terms of total yield of diesel and C5 gasoline.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A catalytic cracking catalyst resistant to iron contamination, characterized in that, Its raw materials include: mesoporous and macroporous materials, zinc-aluminum composite materials, and molecular sieves; wherein, the mesoporous and macroporous materials include kaolin and a first zinc salt loaded in the pores of the kaolin; the zinc-aluminum composite material is obtained by solid-phase ball milling of boehmite and a second zinc salt.

2. The iron-resistant catalytic cracking catalyst according to claim 1, characterized in that, The mass ratio of the zinc-aluminum composite material, the mesoporous material, and the molecular sieve is 40-150:40-180:120-185.

3. The iron-resistant catalytic cracking catalyst according to claim 1, characterized in that, The mesopore volume of the aforementioned mesopore material is 0.50-0.65 cm³. 3 / g.

4. The iron-resistant catalytic cracking catalyst according to claim 1, characterized in that, In the zinc-aluminum composite material, the second zinc salt is calculated as zinc oxide, and the mass ratio of zinc oxide to boehmite is 0.2-0.8:1 (based on dry weight). And / or, the first zinc salt, calculated as zinc oxide, has a mass ratio of kaolin to zinc oxide of 1-10:

1.

5. The iron-resistant catalytic cracking catalyst according to claim 1, characterized in that, The molecules are screened from one or more of HY, REY, USY, REHY, REUSY, and HZSM-5.

6. The iron-resistant catalytic cracking catalyst according to claim 1, characterized in that, The medium-to-large pore material is prepared by a method including the following process: Kaolin is calcined once to obtain dry kaolin. The dry kaolin is then mixed with an alkaline solution and subjected to alkali treatment to obtain pore-enlarged kaolin. A mixture of kaolin, macroporous template agent, and first binder, which has undergone pore-expanding treatment, is subjected to a secondary calcination treatment. The first zinc salt is impregnated and adhered to at least a portion of the pores of the kaolin after the secondary calcination treatment to obtain the medium- and macroporous material.

7. The iron-resistant catalytic cracking catalyst according to claim 6, characterized in that, The temperature of the first roasting treatment is 920-1000℃, and the time is 1-3 hours; The secondary roasting process is carried out at a temperature of 400-600℃ for 1-3 hours.

8. The iron-resistant catalytic cracking catalyst according to claim 6, characterized in that, The macroporous template agent is at least one of glucose, polystyrene microspheres, and polymethyl methacrylate microspheres.

9. A method for preparing an iron-contaminated catalytic cracking catalyst as described in any one of claims 1-8, characterized in that, Includes the following steps: Molecular sieves are added to a mixed system comprising the aforementioned macroporous material, a second binder, and a zinc-aluminum composite material. The mixture is then subjected to a series of processes including mixing and pulping, spray drying, and calcination to obtain the catalytic cracking catalyst.

10. The preparation method according to claim 9, characterized in that, The three calcination processes are carried out at a temperature of 350-650℃ for 1-4 hours.

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