Catalytic cracking catalyst, process for its preparation and use, and process for processing a gas oil

Abstract

The present application relates to the technical field of catalyst, in particular to a catalytic cracking catalyst, a preparation method and application thereof, and a method for processing wax oil. The catalytic cracking catalyst comprises modified molecular sieve, binder and matrix material; wherein the modified molecular sieve is prepared by modifying Y-type molecular sieve, and in the modified molecular sieve, SO4 2‑ content is ≤1wt%; wherein the Na2O content of the catalytic cracking catalyst is ≤0.2wt%. + The catalytic cracking catalyst provided by the present application has the characteristics of high activity, good stability, high crystallinity, strong wax oil conversion capacity, good gasoline selectivity and high total liquid yield; meanwhile, when the catalytic cracking catalyst is used for processing wax oil, the conversion rate of the wax oil can be effectively improved, and the total liquid yield is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to a catalytic cracking catalyst, its preparation method and application, and a method for processing wax oil. Background Technology

[0002] Catalytic cracking, as a primary means of converting heavy oil into lighter products, holds a significant position in my country, with a processing capacity exceeding 200 million tons. Catalysts, as its key core technology, allow for flexible adjustments to product structure, improved product quality, and the achievement of low carbon emissions and efficient heavy oil conversion. Research primarily focuses on improving heavy oil conversion, increasing the yield of high-value-added liquid products, and reducing catalyst consumption.

[0003] CN202010581809.3 discloses a silicon-aluminum material, its preparation, and a low-coke, high-activity heavy oil conversion catalytic cracking catalyst. The anhydrous gravimetric chemical expression of the silicon-aluminum material is: (0-1)Na₂O·(15-50)Al₂O₃·(85-50)SiO₂, with a most probable pore size of 10-100 nm and a specific surface area of ​​150-600 m². 2 The catalyst has a pore volume of 0.5-1.5 mL / g, with pores larger than 10 nm accounting for 70-98% of the total pore volume. This catalytic cracking catalyst exhibits good coke selectivity.

[0004] CN202011016356.6 discloses a catalytic cracking catalyst, its preparation method, and its application. The catalytic cracking catalyst contains a cracking active component, a high specific heat capacity matrix material, clay, and a binder; wherein the high specific heat capacity matrix material contains at least 5% by weight of manganese oxide, and its specific heat capacity is 1.3-2.0 J / (g·K). This catalytic cracking catalyst exhibits excellent resistance to metal contamination and good heavy oil conversion capability, and when used in heavy oil catalytic cracking, it achieves a high yield of light oil.

[0005] CN202210859937.9 discloses a heavy oil catalytic cracking catalyst, which, by weight, comprises: 10-40 parts zeolite molecular sieve, 5-30 parts binder, 1-10 parts mesoporous rare earth-magnesium-aluminum ternary composite oxide, and 20-80 parts clay. This catalytic cracking catalyst exhibits high heavy oil conversion capacity and resistance to heavy metal contamination.

[0006] CN200710121664.3 discloses a heavy oil catalytic cracking catalyst containing 10-50 wt% REY-type molecular sieve (dry basis), 10-40 wt% inorganic oxide binder (oxide basis), and 10-70 wt% clay (dry basis). This catalyst exhibits strong heavy oil cracking capability, high gasoline yield, and strong resistance to vanadium contamination.

[0007] Based on the aforementioned existing technologies, it is known that the high-efficiency heavy oil conversion performance of catalysts is significantly related to the molecular sieve, matrix properties and ratios, preparation techniques, and modifying elements. However, the decisive factor remains the Y-type molecular sieve. Due to its unique three-dimensional pore structure, suitable acidity, and good stability, the Y-type molecular sieve remains the main active component of FCC catalysts. Its performance determines the catalyst's activity, stability, heavy oil conversion performance, and product selectivity, making it a research hotspot for improving heavy oil catalyst performance. Catalytic cracking is a typical acid-catalyzed gas-solid heterogeneous reaction, following a carbocation mechanism. NaY molecular sieves themselves are not acidic and usually require exchange modification to remove Na ions and adjust their acidity and pore structure. Because acidic H... + Excessive acidity can easily damage the framework structure of Y-type molecular sieves, leading to a decrease in crystallinity and selectivity. REY-type molecular sieves, due to their strong acidity and acid density, are prone to coking and deactivation during catalytic cracking reactions. Therefore, the commonly used modification method involves exchanging ammonium salts and / or rare earth elements, followed by thermal or hydrothermal calcination to prepare modified REHY or REUSY molecular sieves with different acidities and pore structures. Currently, the preparation methods for REHY or REUSY molecular sieves are broadly divided into two categories: one is to first exchange a small amount of rare earth ions and / or ammonium ions into NaY molecular sieves, followed by calcination and then treatment with rare earth ions and / or ammonium ions or dealumination to produce REUSY molecular sieves; the other is to first prepare USY molecular sieves from NaY molecular sieves, and then exchange rare earth elements to prepare REUSY.

[0008] Ammonium chloride is prone to high-temperature decomposition and low-temperature crystallization, which can easily clog catalyst flues and bag filters, leading to continuous production disruptions. Ammonium nitrate is also unsuitable due to its explosive potential under high temperature, high pressure, presence of oxidizable substances (reducing agents), and electric sparks, and its high price makes it a key raw material for explosives. Ammonium sulfate is stable and inexpensive, and is often used for industrial molecular sieve exchange modification. However, it readily reacts with rare earth elements to form rare earth sulfate precipitates, which prevent rare earth ions from migrating into the molecular sieve cages and effectively stabilizing the molecular sieve framework. Furthermore, it can easily cause excessive sulfate levels, damaging the molecular sieve framework. Additionally, sulfate ions can be converted into sulfides during oil refining after being made into catalysts, corroding equipment.

[0009] In existing technologies, rare earth precipitation is commonly used to improve rare earth utilization and generate independent rare earth phases, thus enhancing the molecular sieve's resistance to V-fouling. Simultaneous exchange of rare earth and ammonium salts leads to low exchange efficiency due to competitive exchange. Ammonium salt exchange before rare earth exchange using ammonium chloride or ammonium nitrate results in high costs and equipment corrosion. Using low-cost, recyclable ammonium sulfate requires extensive water washing to remove sulfate ions and avoid sulfate precipitation, increasing water consumption. After hydrothermal calcination of rare earth-modified molecular sieves, some rare earth elements inevitably fail to locate in the sodalite cages, leading to subsequent ammonium sulfate exchange and rare earth sulfate precipitation, increasing sulfate content and reducing crystallinity. Pre-exchange can reduce sodium oxide and sulfate content in modified molecular sieves, but it suffers from long processes, high water consumption, and high costs. REY molecular sieves prepared without ammonium salts suffer from high coking rates.

[0010] CN200610087535.2 discloses a method for preparing REY molecular sieves. Although this method uses rare earth exchange, precipitation, filtration, and calcination to prepare a rare earth-modified Y-type molecular sieve with a one-exchange-one-calcination process, and then directly performs ammonium salt exchange to obtain REY molecular sieves, and although the precipitation process in the one-exchange process avoids the loss of rare earths, the rare earths inevitably exist on the outer surface of the molecular sieve or in the supercage space due to the one-exchange-one-calcination process. If ammonium sulfate is used as the exchange agent in the subsequent process, this part of the rare earths is easy to react with sulfate ions to form rare earth sulfate precipitates, resulting in high sulfate content, low crystallinity, and poor stability of the molecular sieve.

[0011] CN02130783.0 discloses a method for ammonium and rare earth ion exchange of molecular sieves. This method uses ammonium sulfate as the ammonium source. While reducing the corrosion of equipment by ammonium chloride vapor formed during the drying and calcination of molecular sieves, it also makes full use of the ammonium sulfate recovered in industry, thus forming a virtuous cycle in industrial production. However, the process is complex and has high water consumption.

[0012] In summary, existing rare earth modified molecular sieves suffer from problems such as high sulfate content, low crystallinity, equipment corrosion, long production process, and high cost. Furthermore, using these rare earth modified molecular sieves to process wax oil results in low catalytic cracking activity, low wax oil conversion rate, low total liquid yield, and equipment corrosion due to the conversion of sulfate to sulfides during the process. Summary of the Invention

[0013] The purpose of this invention is to overcome the above-mentioned technical problems and provide a catalytic cracking catalyst, its preparation method and application, and a method for processing wax oil. The catalytic cracking catalyst has high catalytic activity, stability and crystallinity. When used to process wax oil, it can effectively improve the conversion rate of wax oil and the yield of high value-added liquid products.

[0014] To achieve the above objectives, a first aspect of the present invention provides a catalytic cracking catalyst, the catalytic cracking catalyst comprising: a modified molecular sieve, a binder, and a matrix material; wherein the modified molecular sieve is obtained by modifying a Y-type molecular sieve, and the modified molecular sieve contains SO4 2- Content ≤1wt%;

[0015] In the catalytic cracking catalyst, Na, calculated as Na2O + Content ≤0.2wt%.

[0016] Preferably, in the catalytic cracking catalyst, on a dry basis, the content of the modified molecular sieve is 15-50 wt%, the content of the binder is 5-38 wt%, and the content of the matrix material is 35-80 wt%.

[0017] Preferably, the modification process includes:

[0018] a. The Y-type molecular sieve is subjected to rare earth ion exchange to obtain a rare earth ion slurry;

[0019] b. Add a first precipitant to cause some rare earth ions in the rare earth ion exchange slurry to undergo first precipitation, thereby obtaining a first precipitated slurry;

[0020] c. The first precipitated slurry is sequentially filtered, subjected to first ammonium sulfate exchange, first water washing, and first calcination to obtain a dry molecular sieve powder with one exchange and one calcination step.

[0021] d. Add a second precipitant to allow some rare earth ions in the dry powder of the first-exchange-first-calcination molecular sieve to undergo a second precipitation. Then, proceed with a second ammonium sulfate exchange, a second water wash, and optionally a second calcination to obtain the modified molecular sieve.

[0022] A second aspect of the present invention provides a method for preparing a catalytic cracking catalyst, the method comprising the following steps:

[0023] (1) The modified molecular sieve, binder, matrix material and water are mixed to obtain a slurry;

[0024] (2) The slurry is sequentially homogenized, shaped, and calcined a third time. The resulting catalyst precursor is then subjected to sodium reduction treatment to obtain Na2O. + Catalytic cracking catalyst with a content ≤0.2wt%;

[0025] The modified molecular sieve is prepared by modifying Y-type molecular sieve, and the modified molecular sieve contains SO4. 2- Content ≤1wt%.

[0026] The third aspect of the present invention provides an application of the catalytic cracking catalyst provided in the first aspect, or the catalytic cracking catalyst prepared by the preparation method provided in the second aspect, in heavy oil processing, preferably in wax oil processing.

[0027] A fourth aspect of the present invention provides a method for processing wax oil, the method comprising: catalytically cracking the wax oil in the presence of a catalyst to obtain catalytic cracking products; wherein the catalytic cracking products include: dry gas, liquefied petroleum gas, gasoline, diesel oil, heavy oil, and coke;

[0028] The catalyst is selected from the catalytic cracking catalyst provided in the first aspect, or the catalytic cracking catalyst prepared by the preparation method provided in the second aspect.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] (1) This invention defines the catalytic cracking catalyst as having a specific SO4 content. 2- The modified molecular sieve with high content, combined with the synergistic effect of binder and matrix material, especially the further regulation of the modification process of the modified molecular sieve, as well as the content range of modified molecular sieve, binder and matrix material, makes the catalytic cracking catalyst have the characteristics of high activity, good stability, high crystallinity, strong wax oil conversion ability, good gasoline selectivity and high total liquid yield.

[0031] (2) The modification process of the modified molecular sieve provided by the present invention involves adding a precipitant (i.e., the first precipitant and the second precipitant) to the Y-type molecular sieve after rare earth ion exchange and before ammonium sulfate exchange to generate a metal oxide precipitate precursor with the metal ions. This avoids the formation of precipitates of free rare earth ions and sulfate ions in the exchange system solution, on the surface of the molecular sieve or in the supercage during the subsequent ammonium sulfate exchange to reduce sodium. On the one hand, this achieves the purpose of reducing sulfate ions and improving the crystallinity and stability of the modified molecular sieve. On the other hand, it improves the utilization rate of rare earth ions.

[0032] (3) The preparation method of the catalytic cracking catalyst provided by the present invention is simple, simplifies the process flow, and is convenient for industrial production;

[0033] (4) Using the catalytic cracking catalyst provided by the present invention to process wax oil can effectively improve the conversion rate of wax oil and the total liquid yield; at the same time, it avoids the problem of high sulfate ions in the modified molecular sieve being converted into sulfides and thus corroding the equipment. Detailed Implementation

[0034] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0035] In this invention, unless otherwise specified, "first," "second," and "third" do not indicate a sequence or limit the specific materials or steps; they are merely used to distinguish that these are not the same material or step. For example, in "first water wash," "second water wash," and "third water wash," "first," "second," and "third" are only used to distinguish that these are not the same water wash; similarly, in "first ammonium sulfate exchange" and "second ammonium sulfate exchange," "first" and "second" are only used to indicate that these are not the same ammonium sulfate exchange.

[0036] The first aspect of this invention provides a catalytic cracking catalyst, the catalytic cracking catalyst comprising: a modified molecular sieve, a binder, and a matrix material; wherein the modified molecular sieve is obtained by modifying a Y-type molecular sieve, and the modified molecular sieve contains SO4 2- Content ≤1wt%;

[0037] In the catalytic cracking catalyst, Na, calculated as Na2O + Content ≤0.2wt%.

[0038] The inventors of this invention discovered that by using industrially inexpensive, harmless, and easily recyclable ammonium sulfate as an exchanger, and by adding precipitants such as ammonium oxalate, ammonium carbonate, and ammonia before ammonium sulfate exchange after rare earth ion exchange, the ammonium sulfate preferentially reacts with rare earth ions to form precipitate precursors of rare earth oxides. This avoids the formation of precipitates of free RE ions and sulfate ions in the exchange system solution, on the surface of the molecular sieve, or in the supercage during the subsequent ammonium sulfate exchange for sodium reduction, thereby reducing sulfate ions, improving the crystallinity and stability of the molecular sieve, and simultaneously increasing the utilization rate of rare earth elements. Since Y-type molecular sieves are the main active component of catalytic cracking catalysts, their performance determines the performance of the catalytic cracking catalyst. This invention, through technological innovation, reduces sulfate ions in Y-type molecular sieves, improving their crystallinity and stability. Therefore, when used as an active component of the catalyst, it also correspondingly improves the cracking activity and hydrothermal stability of the catalyst.

[0039] Meanwhile, by further regulating the content range of modified molecular sieves, binders and matrix materials in the catalytic cracking catalyst, the cracking activity and hydrothermal stability of the catalytic cracking catalyst were further improved, thereby increasing the conversion rate of wax oil and the total liquid yield.

[0040] In this invention, unless otherwise specified, SO4 2- Both the Na2O and Na2O content were determined using XRF fluorescence method.

[0041] In some embodiments of the present invention, preferably, the modified molecular sieve content in the catalytic cracking catalyst, on a dry basis, is 15-50 wt%, the binder content is 5-38 wt%, and the matrix material content is 35-80 wt%; more preferably, the modified molecular sieve content in the catalytic cracking catalyst, on a dry basis, is 25-45 wt%, the binder content is 8-35 wt%, and the matrix material content is 35-60 wt%. Using these preferred conditions is more conducive to improving the cracking activity and hydrothermal stability of the catalytic cracking catalyst.

[0042] In this invention, unless otherwise specified, the sum of the contents of the modified molecular sieve, binder and matrix material is ≤100wt%, preferably 100wt%.

[0043] In one specific embodiment of the present invention, the catalytic cracking catalyst is composed of a modified molecular sieve, a binder, and a matrix material; wherein, on a dry basis, the content of the modified molecular sieve in the catalytic cracking catalyst is 15-50 wt%, preferably 25-45 wt%; the content of the binder is 5-38 wt%, preferably 8-35 wt%; and the content of the matrix material is 35-80 wt%, preferably 35-60 wt%.

[0044] In this invention, the modification process for the modified molecular sieve has a wide range of options, as long as the SO4 content in the modified molecular sieve is within a certain range. 2- The content ≤1wt% is acceptable. Preferably, the modification process includes:

[0045] a. The Y-type molecular sieve is subjected to rare earth ion exchange to obtain a rare earth ion slurry;

[0046] b. Add a first precipitant to cause some rare earth ions in the rare earth ion exchange slurry to undergo first precipitation, thereby obtaining a first precipitated slurry;

[0047] c. The first precipitated slurry is sequentially filtered, subjected to first ammonium sulfate exchange, first water washing, and first calcination to obtain a dry molecular sieve powder with one exchange and one calcination step.

[0048] d. Add a second precipitant to allow some rare earth ions in the dry powder of the first-exchange-first-calcination molecular sieve to undergo a second precipitation, followed by a second ammonium sulfate exchange, a second water wash, and optionally a second calcination, to obtain the modified molecular sieve.

[0049] In this invention, the selection range for the Y-type molecular sieve is relatively wide. Preferably, the silica-alumina ratio of the Y-type molecular sieve is 2-100, for example, 2, 5, 10, 15, 20, 30, 40, 50, 80, 100, and any value within any range of two such values, preferably 2-50. The silica-alumina ratio is the molar ratio of silicon oxide to aluminum oxide, and the silica-alumina ratio parameter is measured using XRF or ICP.

[0050] In some embodiments of the present invention, preferably, the Y-type molecular sieve is selected from at least one of NaY molecular sieve, NaHY molecular sieve, NaUSY molecular sieve, NaREHY molecular sieve and NaREUSY molecular sieve, more preferably selected from NaY molecular sieve and / or NaHY molecular sieve, and more preferably NaY molecular sieve.

[0051] In some embodiments of the present invention, preferably, in step a, the conditions for rare earth ion exchange include: a temperature of 25-180℃, preferably 50-80℃; a pH of 2.8-6.5, preferably 3.5-4.5; and a time of 0.3-3.5h, preferably 0.5-1.5h.

[0052] In some embodiments of the present invention, preferably, the rare earth ion exchange process includes: mixing the Y-type molecular sieve with water, and then adding soluble rare earth salts to carry out the rare earth ion exchange.

[0053] In some embodiments of the present invention, preferably, the weight ratio of the Y-type molecular sieve to water is 1:1.5-30, for example, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:10, 1:20, 1:30, and any value within any two numerical ranges, preferably 1:2-5.

[0054] In some embodiments of the present invention, preferably, the content of the soluble rare earth salt, calculated as RE2O3, in the Y-type molecular sieve on a dry basis is 1-20 wt%, for example, 1 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%, 16 wt%, 20 wt%, and any value within any range of two such values, preferably 6-16 wt%. Using these preferred conditions is more conducive to eliminating the influence of sulfate on the performance of the modified molecular sieve and improving the crystallinity and catalytic cracking performance of the modified molecular sieve.

[0055] In this invention, during the rare earth ion exchange process, the rare earth ions in the soluble rare earth salt are completely attached to the surface and internal pores of the Y-type molecular sieve. Therefore, the weight ratio of the Y-type molecular sieve on a dry basis to the soluble rare earth salt on a RE2O3 basis is 100:1-20, preferably 100:6-16.

[0056] In this invention, unless otherwise specified, solubility means being easily soluble in water or being easily soluble in water with the help of additives.

[0057] In some embodiments of the present invention, preferably, the soluble rare earth salt is selected from chlorates and / or nitrates containing at least one rare earth element. The rare earth element includes, but is not limited to, lanthanum, cerium, yttrium, etc., and the soluble rare earth salt includes, but is not limited to, lanthanum chloride, lanthanum nitrate, cerium chloride, cerium nitrate, yttrium chloride, yttrium nitrate, etc.

[0058] In some embodiments of the present invention, preferably, in step b, the amount of the first precipitant satisfies the molar ratio of rare earth ions in the Y-type molecular sieve containing 1-4 wt% after the first precipitation; more preferably, the amount of the first precipitant satisfies the molar ratio of rare earth ions in the Y-type molecular sieve containing 1.5-2.5 wt% after the first precipitation. Using these preferred conditions is more conducive to reducing the sulfate content of the modified molecular sieve, thereby improving the crystallinity and catalytic performance of the modified molecular sieve.

[0059] In this invention, a wide range of types of the first precipitant can be selected, as long as the rare earth ions are used to generate rare earth oxide precipitate precursors. Preferably, the first precipitant is selected from at least one of ammonium oxalate, ammonium carbonate, ammonium bicarbonate, ammonia, urea, and ammonium acetate, and more preferably from at least one of ammonium oxalate, ammonium carbonate, ammonium bicarbonate, and ammonia.

[0060] In some embodiments of the present invention, preferably, the conditions for the first precipitation include: a temperature of 25-180°C, preferably 50-80°C; and a time of 0.1-5h, preferably 0.1-2h.

[0061] In this invention, the first ammonium sulfate exchange is intended to further exchange Na in the Y-type molecular sieve. + Preferably, in step c, the first ammonium sulfate exchange process includes: exchanging the filtered product with the first ammonium sulfate aqueous solution.

[0062] In some embodiments of the present invention, preferably, the weight ratio of the first ammonium sulfate aqueous solution and the Y-type molecular sieve, calculated as ammonium sulfate, is 5-50:100, for example, 5:100, 10:100, 15:100, 20:100, 25:100, 30:100, 40:100, 50:100, and any value within the range of any two values, preferably 10-25:100.

[0063] In some embodiments of the present invention, preferably, the concentration of ammonium sulfate in the first ammonium sulfate aqueous solution is 20-400 g / L, for example, 20 g / L, 50 g / L, 80 g / L, 120 g / L, 150 g / L, 200 g / L, 250 g / L, 300 g / L, 400 g / L, and any value within the range of any two values, preferably 120-250 g / L.

[0064] In some embodiments of the present invention, preferably, the conditions for the first ammonium sulfate exchange include: a temperature of 15-150°C, preferably 50-80°C; and a time of 0.1-5 h, preferably 0.5-2 h.

[0065] In some embodiments of the present invention, preferably, in the first water wash, the amount of water used is 1-8 times the weight of the Y-type molecular sieve, for example, 1, 2, 3, 4, 5, 8 times, and any value within the range of any two values, preferably 2-5 times.

[0066] In some embodiments of the present invention, preferably, the conditions for the first calcination include: a 100% steam atmosphere; a temperature of 400-700°C, preferably 500-650°C; and a time of 0.1-5 h, preferably 0.5-3 h.

[0067] In some embodiments of the present invention, preferably, the amount of the second precipitant satisfies the molar ratio of rare earth ions in the dry powder of the cross-linked and calcined molecular sieve, where the content is 0.5-3 wt%, after the second precipitation; more preferably, the amount of the second precipitant satisfies the molar ratio of rare earth ions in the dry powder of the cross-linked and calcined molecular sieve, where the content is 1-2 wt%, after the second precipitation. Using these preferred conditions is more conducive to reducing the sulfate content of the modified molecular sieve, thereby improving the crystallinity and catalytic cracking performance of the modified molecular sieve.

[0068] In some embodiments of the present invention, preferably, the second precipitant is selected from at least one of ammonium oxalate, ammonium carbonate, ammonium bicarbonate, ammonia, urea and ammonium acetate, and more preferably from at least one of ammonium oxalate, ammonium carbonate, ammonium bicarbonate and ammonia.

[0069] In some embodiments of the present invention, preferably, the conditions for the second precipitation include: a temperature of 15-40°C, preferably 20-30°C; and a time of 0.1-5h, preferably 0.1-2h.

[0070] In some embodiments of the present invention, preferably, in step d, the process of exchanging the second ammonium sulfate includes: exchanging the second precipitate product with the second ammonium sulfate aqueous solution.

[0071] In some embodiments of the present invention, preferably, the weight ratio of the second ammonium sulfate aqueous solution (calculated as ammonium sulfate) to the dry powder of the cyclohexane-baked molecular sieve is 5-50:100, for example, 5:100, 10:100, 15:100, 20:100, 25:100, 30:100, 40:100, 50:100, and any value within the range of any two values, preferably 10-25:100.

[0072] In some embodiments of the present invention, preferably, the concentration of ammonium sulfate in the second ammonium sulfate aqueous solution is 20-400 g / L, for example, 20 g / L, 50 g / L, 80 g / L, 120 g / L, 150 g / L, 200 g / L, 250 g / L, 300 g / L, 400 g / L, and any value within the range of any two values, preferably 120-250 g / L.

[0073] In some embodiments of the present invention, preferably, the conditions for the second ammonium sulfate exchange include: a temperature of 20-85°C, preferably 50-80°C; and a time of 0.1-5 h, preferably 0.1-2 h.

[0074] In some embodiments of the present invention, preferably, in the second water washing, the amount of water used is 1-8 times the weight of the dry powder of the one-cross-baked molecular sieve, for example, 1, 2, 3, 4, 5, 8 times, and any value in the range of any two values, preferably 2-5 times.

[0075] In some embodiments of the present invention, preferably, the conditions for the second calcination include: a 20-100% water vapor atmosphere; a temperature of 400-700°C, preferably 450-650°C; and a time of 0.1-10 h, preferably 0.5-5 h.

[0076] In some embodiments of the present invention, preferably, the dry powder of the cyclohexane-baked molecular sieve and water are mixed before the second precipitation; more preferably, the weight ratio of the dry powder of the cyclohexane-baked molecular sieve to water is 1:1.5-30, for example, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:10, 1:20, 1:30, and any value within the range of any two values, preferably 1:2-5.

[0077] In some embodiments of the present invention, preferably, the binder is selected from at least one of alumina sol, acidified boehmite, acidic silica sol, and phosphoalumina sol, and more preferably from at least one of alumina sol, acidified boehmite, and acidic silica sol.

[0078] In some embodiments of the present invention, preferably, the matrix material is selected from at least one of kaolin, halloysite, porous stone, diatomite, hydrous stone, macroporous alumina, boehmite, and macroporous aluminosilicate materials.

[0079] In this invention, the modified molecular sieve, in addition to having lower SO4 content, 2- In addition to its low sodium content, it also has low sodium content. + Content, high RE 3+ High content and high crystallinity. Preferably, in the modified molecular sieve, SO4 content is high. 2- Content ≤0.5wt%, preferably 0.01-0.45wt%; Na calculated as Na₂O + Content ≤1.2wt%, preferably ≤1wt%; RE calculated as RE2O3 3+ Content ≥5wt%, preferably 6-16wt%; C / CO ≥55, preferably 55-70.

[0080] In this invention, unless otherwise specified, the RE2O3 content is determined by XRF fluorescence method; the C / C ratio is determined by X-ray diffraction method.

[0081] In some embodiments of the present invention, preferably, the catalytic cracking catalyst contains Na, calculated as Na₂O. + The content is 0.05-0.2 wt%.

[0082] A second aspect of the present invention provides a method for preparing a catalytic cracking catalyst, the method comprising the following steps:

[0083] (1) The modified molecular sieve, binder, matrix material and water are mixed to obtain a slurry;

[0084] (2) The slurry is sequentially homogenized, shaped, and calcined a third time. The resulting catalyst precursor is then subjected to sodium reduction treatment to obtain Na2O. + Catalytic cracking catalyst with a content ≤0.2wt%;

[0085] The modified molecular sieve is prepared by modifying Y-type molecular sieve, and the modified molecular sieve contains SO4. 2- Content ≤1wt%.

[0086] In this invention, the mixing conditions in step (1) have a wide range of options, as long as the modified molecular sieve, binder, matrix material, and water are mixed evenly. Preferably, the mixing conditions include: a temperature of 15-70°C, more preferably 25-60°C; and a time of 0.1-5 h, most preferably 0.1-3 h.

[0087] In some embodiments of the present invention, preferably, in step (1), the weight ratio of the modified molecular sieve, binder, and matrix material is 15-50:5-38:35-80, more preferably 25-45:8-35:35-60. In the present invention, the types of the modified molecular sieve, binder, and matrix material are all as defined above, and will not be elaborated further.

[0088] In some embodiments of the present invention, preferably, the solid content of the slurry is 25-50 wt%, for example, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, and any value within a range of any two values, preferably 30-50 wt%.

[0089] In this invention, the homogenization refines the slurry particles to ensure uniform mixing. Preferably, the homogenization results in an average particle size of ≤4μm in the slurry, for example, 0.5μm, 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 4μm, and any value within the range of any two numbers, preferably 0.5-3μm.

[0090] In this invention, a wide range of molding types can be selected. Preferably, the molding process is selected from spray molding.

[0091] In some embodiments of the present invention, preferably, in step (2), the conditions for the third calcination include: a temperature of 400-550°C, preferably 450-500°C; and a time of 0.1-5h, preferably 0.1-2h.

[0092] In some embodiments of the present invention, preferably, the sodium reduction process includes: sequentially mixing a slurry containing a catalyst precursor and an ammonium salt, filtering, washing with a third water, and drying to obtain the catalytic cracking catalyst.

[0093] In this invention, the slurry containing the catalyst precursor refers to an aqueous solution containing the catalyst precursor. Preferably, the solid content of the slurry containing the catalyst precursor is 10-40 wt%, for example, 10 wt%, 20 wt%, 25 wt%, 30 wt%, 32 wt%, 35 wt%, 38 wt%, 40 wt%, and any value within any range of any two of these values, preferably 30-38 wt%.

[0094] In this invention, the ammonium salt includes, but is not limited to, ammonium chloride and / or ammonium nitrate, and is preferably ammonium chloride.

[0095] In some embodiments of the present invention, preferably, the weight ratio of the ammonium salt to the catalyst precursor-containing slurry, based on the catalyst precursor, is 1-10:100, for example, 1:100, 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 10:100, and any value within the range of any two values, preferably 3-8:100.

[0096] In some embodiments of the present invention, preferably, in the third water wash, the amount of water used is 1-8 times the weight of the catalytic cracking catalyst, for example, 1, 1.5, 2, 2.5, 3, 4, 5, 8 times, and any value within the range of any two values, preferably 1.5-3 times.

[0097] In this invention, the drying conditions during the sodium reduction process are limited to removing only the residual water from the third water washing product.

[0098] In some embodiments of the present invention, preferably, the modification process includes:

[0099] a. The Y-type molecular sieve is subjected to rare earth ion exchange to obtain a rare earth ion slurry;

[0100] b. Add a first precipitant to cause some rare earth ions in the rare earth ion exchange slurry to undergo first precipitation, thereby obtaining a first precipitated slurry;

[0101] c. The first precipitated slurry is sequentially filtered, subjected to first ammonium sulfate exchange, first water washing, and first calcination to obtain a dry molecular sieve powder with one exchange and one calcination step.

[0102] d. Add a second precipitant to allow some rare earth ions in the dry powder of the first-exchange-first-calcination molecular sieve to undergo a second precipitation, followed by a second ammonium sulfate exchange, a second water wash, and optionally a second calcination, to obtain the modified molecular sieve.

[0103] In this invention, the selection range for the Y-type molecular sieve is relatively wide. Preferably, the silica-alumina ratio of the Y-type molecular sieve is 2-100, for example, 2, 5, 10, 15, 20, 30, 40, 50, 80, 100, and any value within any range of two such values, preferably 2-50. The silica-alumina ratio is the molar ratio of silicon oxide to aluminum oxide, and the silica-alumina ratio parameter is measured using XRF or ICP.

[0104] In some embodiments of the present invention, preferably, the Y-type molecular sieve is selected from at least one of NaY molecular sieve, NaHY molecular sieve, NaUSY molecular sieve, NaREHY molecular sieve and NaREUSY molecular sieve, more preferably selected from NaY molecular sieve and / or NaHY molecular sieve, and more preferably NaY molecular sieve.

[0105] In some embodiments of the present invention, preferably, in step a, the conditions for rare earth ion exchange include: a temperature of 25-180℃, preferably 50-80℃; a pH of 2.8-6.5, preferably 3.5-4.5; and a time of 0.3-3.5h, preferably 0.5-1.5h.

[0106] In some embodiments of the present invention, preferably, the rare earth ion exchange process includes: mixing the Y-type molecular sieve with water, and then adding soluble rare earth salts to carry out the rare earth ion exchange.

[0107] In some embodiments of the present invention, preferably, the weight ratio of the Y-type molecular sieve to water is 1:1.5-30, for example, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:10, 1:20, 1:30, and any value within any two numerical ranges, preferably 1:2-5.

[0108] In some embodiments of the present invention, preferably, the content of the soluble rare earth salt, calculated as RE2O3, in the Y-type molecular sieve on a dry basis is 1-20 wt%, for example, 1 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%, 16 wt%, 20 wt%, and any value within any range of two such values, preferably 6-16 wt%. Using these preferred conditions is more conducive to eliminating the influence of sulfate on the performance of the modified molecular sieve and improving the crystallinity and catalytic cracking performance of the modified molecular sieve.

[0109] In this invention, during the rare earth ion exchange process, the rare earth ions in the soluble rare earth salt are completely attached to the surface and internal pores of the Y-type molecular sieve. Therefore, the weight ratio of the Y-type molecular sieve on a dry basis to the soluble rare earth salt on a RE2O3 basis is 100:1-20, preferably 100:6-16.

[0110] In this invention, unless otherwise specified, solubility means being easily soluble in water or being easily soluble in water with the help of additives.

[0111] In some embodiments of the present invention, preferably, the soluble rare earth salt is selected from chlorates and / or nitrates containing at least one rare earth element. The rare earth element includes, but is not limited to, lanthanum, cerium, yttrium, etc., and the soluble rare earth salt includes, but is not limited to, lanthanum chloride, lanthanum nitrate, cerium chloride, cerium nitrate, yttrium chloride, yttrium nitrate, etc.

[0112] In some embodiments of the present invention, preferably, in step b, the amount of the first precipitant satisfies the molar ratio of rare earth ions in the Y-type molecular sieve containing 1-4 wt% after the first precipitation; more preferably, the amount of the first precipitant satisfies the molar ratio of rare earth ions in the Y-type molecular sieve containing 1.5-2.5 wt% after the first precipitation. Using these preferred conditions is more conducive to reducing the sulfate content of the modified molecular sieve, thereby improving the crystallinity and catalytic performance of the modified molecular sieve.

[0113] In this invention, a wide range of types of the first precipitant can be selected, as long as the rare earth ions are used to generate rare earth oxide precipitate precursors. Preferably, the first precipitant is selected from at least one of ammonium oxalate, ammonium carbonate, ammonium bicarbonate, ammonia, urea, and ammonium acetate, and more preferably from at least one of ammonium oxalate, ammonium carbonate, ammonium bicarbonate, and ammonia.

[0114] In some embodiments of the present invention, preferably, the conditions for the first precipitation include: a temperature of 25-180°C, preferably 50-80°C; and a time of 0.1-5h, preferably 0.1-2h.

[0115] In this invention, the first ammonium sulfate exchange is intended to further exchange Na in the Y-type molecular sieve. + Preferably, in step c, the first ammonium sulfate exchange process includes: exchanging the filtered product with the first ammonium sulfate aqueous solution.

[0116] In some embodiments of the present invention, preferably, the weight ratio of the first ammonium sulfate aqueous solution and the Y-type molecular sieve, calculated as ammonium sulfate, is 5-50:100, for example, 5:100, 10:100, 15:100, 20:100, 25:100, 30:100, 40:100, 50:100, and any value within the range of any two values, preferably 10-25:100.

[0117] In some embodiments of the present invention, preferably, the concentration of ammonium sulfate in the first ammonium sulfate aqueous solution is 20-400 g / L, for example, 20 g / L, 50 g / L, 80 g / L, 120 g / L, 150 g / L, 200 g / L, 250 g / L, 300 g / L, 400 g / L, and any value within the range of any two values, preferably 120-250 g / L.

[0118] In some embodiments of the present invention, preferably, the conditions for the first ammonium sulfate exchange include: a temperature of 15-150°C, preferably 50-80°C; and a time of 0.1-5 h, preferably 0.5-2 h.

[0119] In some embodiments of the present invention, preferably, in the first water wash, the amount of water used is 1-8 times the weight of the Y-type molecular sieve, for example, 1, 2, 3, 4, 5, 8 times, and any value within the range of any two values, preferably 2-5 times.

[0120] In some embodiments of the present invention, preferably, the conditions for the first calcination include: a 100% steam atmosphere; a temperature of 400-700°C, preferably 500-650°C; and a time of 0.1-5 h, preferably 0.5-3 h.

[0121] In some embodiments of the present invention, preferably, the amount of the second precipitant satisfies the molar ratio of rare earth ions in the dry powder of the cross-linked and calcined molecular sieve, where the content is 0.5-3 wt%, after the second precipitation; more preferably, the amount of the second precipitant satisfies the molar ratio of rare earth ions in the dry powder of the cross-linked and calcined molecular sieve, where the content is 1-2 wt%, after the second precipitation. Using these preferred conditions is more conducive to reducing the sulfate content of the modified molecular sieve, thereby improving the crystallinity and catalytic cracking performance of the modified molecular sieve.

[0122] In some embodiments of the present invention, preferably, the second precipitant is selected from at least one of ammonium oxalate, ammonium carbonate, ammonium bicarbonate, ammonia, urea and ammonium acetate, and more preferably from at least one of ammonium oxalate, ammonium carbonate, ammonium bicarbonate and ammonia.

[0123] In some embodiments of the present invention, preferably, the conditions for the second precipitation include: a temperature of 15-40°C, preferably 20-30°C; and a time of 0.1-5h, preferably 0.1-2h.

[0124] In some embodiments of the present invention, preferably, in step d, the process of exchanging the second ammonium sulfate includes: exchanging the second precipitate product with the second ammonium sulfate aqueous solution.

[0125] In some embodiments of the present invention, preferably, the weight ratio of the second ammonium sulfate aqueous solution (calculated as ammonium sulfate) to the dry powder of the cyclohexane-baked molecular sieve is 5-50:100, for example, 5:100, 10:100, 15:100, 20:100, 25:100, 30:100, 40:100, 50:100, and any value within the range of any two values, preferably 10-25:100.

[0126] In some embodiments of the present invention, preferably, the concentration of ammonium sulfate in the second ammonium sulfate aqueous solution is 20-400 g / L, for example, 20 g / L, 50 g / L, 80 g / L, 120 g / L, 150 g / L, 200 g / L, 250 g / L, 300 g / L, 400 g / L, and any value within the range of any two values, preferably 120-250 g / L.

[0127] In some embodiments of the present invention, preferably, the conditions for the second ammonium sulfate exchange include: a temperature of 20-85°C, preferably 50-80°C; and a time of 0.1-5 h, preferably 0.1-2 h.

[0128] In some embodiments of the present invention, preferably, in the second water washing, the amount of water used is 1-8 times the weight of the dry powder of the one-cross-baked molecular sieve, for example, 1, 2, 3, 4, 5, 8 times, and any value in the range of any two values, preferably 2-5 times.

[0129] In some embodiments of the present invention, preferably, the conditions for the second calcination include: a 20-100% water vapor atmosphere; a temperature of 400-700°C, preferably 450-650°C; and a time of 0.1-10 h, preferably 0.5-5 h.

[0130] In some embodiments of the present invention, preferably, the dry powder of the cyclohexane-baked molecular sieve and water are mixed before the second precipitation; more preferably, the weight ratio of the dry powder of the cyclohexane-baked molecular sieve to water is 1:1.5-30, for example, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:10, 1:20, 1:30, and any value within the range of any two values, preferably 1:2-5.

[0131] The third aspect of the present invention provides an application of the catalytic cracking catalyst provided in the first aspect, or the catalytic cracking catalyst prepared by the preparation method provided in the second aspect, in heavy oil processing, preferably in wax oil processing.

[0132] A fourth aspect of the present invention provides a method for processing wax oil, the method comprising: catalytically cracking the wax oil in the presence of a catalyst to obtain catalytic cracking products; wherein the catalytic cracking products include: dry gas, liquefied petroleum gas, gasoline, diesel oil, heavy oil, and coke;

[0133] The catalyst is selected from the catalytic cracking catalyst provided in the first aspect, or the catalytic cracking catalyst prepared by the preparation method provided in the second aspect.

[0134] In some embodiments of the present invention, preferably, the weight ratio of the catalyst to the wax oil is 4-12:1, for example, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 12:1, and any value within any range of two such values, preferably 6-9:1. Using these preferred conditions is more conducive to improving the conversion rate of the wax oil and the total liquid yield. In the present invention, the total liquid yield refers to the sum of the yields of liquefied petroleum gas, gasoline, and diesel oil.

[0135] In this invention, the conditions for catalytic cracking are not limited. The conditions for catalytic cracking depend not only on the types and amounts of reactants (wax oil and catalyst) but also on different reaction devices (fixed fluidized bed reactor, riser reactor, etc.).

[0136] According to a particularly preferred embodiment of the present invention, a catalytic cracking catalyst comprises: a modified molecular sieve, a binder, and a matrix material; wherein the modified molecular sieve is obtained by modifying a Y-type molecular sieve, and the modified molecular sieve contains SO4 2- Content ≤0.5wt%;

[0137] In the catalytic cracking catalyst, Na, calculated as Na2O + Content ≤0.2wt%;

[0138] In the catalytic cracking catalyst, on a dry basis, the content of the modified molecular sieve is 25-45 wt%, the content of the binder is 8-35 wt%, and the content of the matrix material is 35-60 wt%. The modification process includes:

[0139] a. The Y-type molecular sieve is subjected to rare earth ion exchange to obtain a rare earth ion slurry;

[0140] b. Add a first precipitant to cause some rare earth ions in the rare earth ion exchange slurry to undergo first precipitation, thereby obtaining a first precipitated slurry;

[0141] c. The first precipitated slurry is sequentially filtered, subjected to first ammonium sulfate exchange, first water washing, and first calcination to obtain a dry molecular sieve powder with one exchange and one calcination step.

[0142] d. Add a second precipitant to allow some rare earth ions in the dry powder of the first-exchange-first-calcination molecular sieve to undergo a second precipitation, followed by a second ammonium sulfate exchange, a second water wash, and optionally a second calcination, to obtain the modified molecular sieve.

[0143] The present invention will be described in detail below through embodiments.

[0144] NaY molecular sieve (silicon-to-aluminum ratio of 5.1, crystallinity of 95%) was purchased from a commercially available product manufactured by Changting Catalyst Co., Ltd.

[0145] Boehmite (loss on ignition 36.7%), kaolin (loss on ignition 18.4%), halloysite (loss on ignition 23.2%), porous stone (loss on ignition 18.2%), diatomaceous earth (loss on ignition 23.6%), sepiolite (loss on ignition 25.3%), macroporous alumina (loss on ignition 16.8%), boehmite (loss on ignition 14.5%), macroporous aluminosilicate material (solid content 15.4%, pore volume 1.15 mL / g); alumina sol containing 22.6 wt% alumina; silica sol containing 30.5 wt% silica, all of which are industrially qualified products.

[0146] SO4 2- The contents of Na2O and RE2O3 were all determined by XRF fluorescence method;

[0147] Crystallinity (C / C0) was measured using X-ray diffraction.

[0148] The microreactor activity parameters were tested as follows: the samples were pretreated at 800℃ and 100% steam for different times; the reaction raw material was Dagang light diesel oil, the reaction temperature was 460℃, the reaction time was 70s, the catalyst loading was 5g, the catalyst-to-oil weight ratio was 3.2, and the total conversion rate was used as the microreactor activity.

[0149] The physical properties of the modified molecular sieves (Z1-Z7 and DZ1-DZ4) prepared in Examples 1-11 are listed in Table 1.

[0150] Preparation Example 1

[0151] a. Pulverize 1000g (dry weight) of NaY molecular sieve with 5L of deionized water, then add 0.537L (as La2O3) of a LaCl3 solution with a concentration of 298g / L. 3+ Rare earth ion exchange was carried out at 0.98 mol (temperature 80℃, time 0.5h) to obtain rare earth ion exchange slurry; wherein, the content of LaCl3, calculated as La2O3, in NaY molecular sieve on a dry basis was 16 wt%.

[0152] b. Adding (32g, 0.225mol) ammonium oxalate monohydrate can reduce the 2.4wt% La in the above metal ion exchange slurry. 3+ The first sedimentation was carried out (at a temperature of 80℃ for 0.5 hours) to obtain the first sedimentation slurry;

[0153] c. Filter the first precipitate slurry, dry it, add 0.833L of ammonium sulfate aqueous solution with a concentration of 180g / L, exchange it at 60℃ for 1h, dry it, rinse it with 3L of water, and then calcine it at 500℃ for 2h in a 100% water vapor atmosphere to obtain the dry powder of the 1-exchange-1-calcined molecular sieve.

[0154] d. After slurrying 1000g (dry weight) of the above-mentioned cyclohexane-calcined molecular sieve powder with 5L of deionized water, add (25.6g, 0.18mol) of ammonium oxalate monohydrate. This will allow the 2wt% La content in the above-mentioned cyclohexane-calcined molecular sieve powder to be reduced. 3+ After the second precipitation (temperature 25℃, time 0.5h), 0.6L of ammonium sulfate aqueous solution with a concentration of 250g / L was added, and the mixture was exchanged at 80℃ for 1.5h. After filtration, the mixture was dried, rinsed with 5L of water, and calcined at 450℃ for 2h in a 100% water vapor atmosphere to obtain modified molecular sieve Z1.

[0155] Preparation Example 2

[0156] a. Pulverize 1000g (dry weight) of NaY molecular sieve with 5L of deionized water, then add 0.358L of La(NO3)3 solution with a concentration of 280g / L (calculated as La2O3). 3+ Rare earth ion exchange was carried out at 0.615 mol (temperature 50℃, time 1.5h) to obtain rare earth ion exchange slurry; wherein, the content of La(NO3)3, calculated as La2O3, in NaY molecular sieve on a dry basis was 10 wt%.

[0157] b. Adding (25.6 g, 0.18 mol) ammonium oxalate monohydrate can reduce the 2 wt% La in the above metal ion exchange slurry. 3+ The first sedimentation was carried out (at a temperature of 50°C for 0.5 hours) to obtain the first sedimentation slurry;

[0158] c. Filter the first precipitate slurry, dry it, add 1.111L of ammonium sulfate aqueous solution with a concentration of 180g / L, exchange it at 80℃ for 1h, dry it, add 3L of water to rinse it, and then calcine it at 600℃ for 2h in a 100% water vapor atmosphere to obtain the dry powder of the 1-exchange-1-calcined molecular sieve.

[0159] d. After slurrying 1000g (dry weight) of the above-mentioned cyclohexane-calcined molecular sieve powder with 5L of deionized water, add (13g, 0.135mol) of ammonium carbonate to achieve a 1.5wt% La content in the above-mentioned cyclohexane-calcined molecular sieve powder. 3+After the second precipitation (temperature 25℃, time 0.5h), 1.666L of ammonium sulfate aqueous solution with a concentration of 120g / L was added, and the mixture was exchanged at 50℃ for 1h. After filtration, the mixture was dried, rinsed with 2L of water, and calcined at 500℃ for 2.5h in an 80% water vapor atmosphere to obtain modified molecular sieve Z2.

[0160] Preparation Example 3

[0161] a. Pulverize 1000g (dry weight) of NaY molecular sieve with 5L of deionized water, then add 0.407L of YCl3 solution with a concentration of 246g / L (calculated as Y2O3). 3+ Rare earth ion exchange was carried out at 0.513 mol (temperature 60℃, time 1h) to obtain rare earth ion exchange slurry; wherein, the content of YCl3, calculated as Y2O3, in NaY molecular sieve on a dry basis was 5.97 wt%.

[0162] b. Adding (32g, 0.225mol) ammonium oxalate monohydrate can reduce the concentration of Y in the above metal ion exchange slurry to 1.7wt%. 3+ The first sedimentation was carried out (at a temperature of 60℃ for 0.5 hours) to obtain the first sedimentation slurry;

[0163] c. Filter the first precipitate slurry, dry it, add 1.389L of ammonium sulfate aqueous solution with a concentration of 180g / L, exchange it at 60℃ for 1.5h, dry it, rinse it with 3L of water, and then calcine it at 650℃ for 2h in a 100% water vapor atmosphere to obtain the dry powder of the 1-exchange-1-calcined molecular sieve.

[0164] d. After slurrying 1000g (dry weight) of the above-mentioned cyclohexane-calcined molecular sieve powder with 5L of deionized water, add (22.6g, 0.16mol) of ammonium oxalate monohydrate to achieve a 1.2wt% Y content in the above-mentioned cyclohexane-calcined molecular sieve powder. 3+ After the second precipitation (temperature 25℃, time 0.5h), 1.389L of ammonium sulfate aqueous solution with a concentration of 180g / L was added, and the mixture was exchanged at 50℃ for 1h. After filtration, the mixture was dried, rinsed with 3L of water, and calcined at 650℃ for 2h in a 60% water vapor atmosphere to obtain modified molecular sieve Z3.

[0165] Preparation Example 4

[0166] a. Pulverize 1000g (dry weight) of NaY molecular sieve with 5L of deionized water, then add 0.43L of a mixed RECl3 solution with a concentration of 326g / L (calculated as RE2O3) (the weight ratio of Ce2O3 to La2O3 is 6:4; RECl3 is 4:4). 3+Metal ion exchange was performed using 0.9287 mol of the solution (at 60 °C for 1 h) to obtain a metal ion exchange slurry; wherein the content of RECl3, calculated as RE2O3, in the NaY molecular sieve on a dry basis was 14 wt%.

[0167] b. Adding (25.6 g, 0.18 mol) ammonium oxalate monohydrate, followed by 5 mL of 28% industrial ammonia, will allow the 2.4 wt% RE in the above metal ion exchange slurry to be released. 3+ The first sedimentation was carried out (at a temperature of 60℃ for 0.5 hours) to obtain the first sedimentation slurry;

[0168] c. Filter the first precipitate slurry, dry it, add 1.222L of ammonium sulfate aqueous solution with a concentration of 180g / L, exchange it at 100℃ for 0.5h, dry it, rinse it with 5L of water, and then calcine it at 600℃ for 2h in a 100% water vapor atmosphere to obtain the dry powder of the 1-exchange-1-calcined molecular sieve.

[0169] d. After slurrying 1000g (dry weight) of the above-mentioned cyclohexane-calcined molecular sieve powder with 5L of deionized water, add (18g, 0.187mol) of ammonium carbonate to achieve a RE content of 1.8wt% in the above-mentioned cyclohexane-calcined molecular sieve powder. 3+ After the second precipitation (temperature 25℃, time 0.5h), 1L of ammonium sulfate aqueous solution with a concentration of 120g / L was added, and the mixture was exchanged at 25℃ for 1h. After filtration, the mixture was dried, rinsed with 4L of water, and calcined at 550℃ for 2h in a 20% water vapor atmosphere to obtain modified molecular sieve Z4.

[0170] Preparation Example 5

[0171] Following the method of Preparation Example 1, except that in step a, 0.537 L (based on La2O3) of LaCl3 solution with a concentration of 298 g / L was replaced with 0.67 L (based on La2O3) of LaCl3 solution with a concentration of 298 g / L, so that the content of LaCl3 in the NaY molecular sieve on a dry basis was 20 wt%; the other conditions were the same, and modified molecular sieve Z5 was obtained.

[0172] Preparation Example 6

[0173] The method is the same as in Example 1, except that in step b, (32 g, 0.225 mol) ammonium oxalate monohydrate is replaced with (12.8 g, 0.09 mol) ammonium oxalate monohydrate, so that the above metal ion exchange slurry contains 1 wt% La 3+ The first precipitation was carried out (temperature 80℃, time 0.5h); under the same other conditions, modified molecular sieve Z6 was obtained.

[0174] Preparation Example 7

[0175] The method is the same as in Example 1, except that in step d, (25.6 g, 0.18 mol) ammonium oxalate monohydrate is replaced with (6.4 g, 0.045 mol) ammonium oxalate monohydrate, so that the above-mentioned cyclohexane-baked molecular sieve dry powder contains 0.5 wt% La 3+ A second precipitation was carried out (temperature 25℃, time 0.5h); under the same other conditions, modified molecular sieve Z7 was obtained.

[0176] Preparation Example 8

[0177] Modified molecular sieve DZ1 was prepared according to the method disclosed in CN200610087535.2, i.e.

[0178] Take 1000g (dry weight) of NaY molecular sieve, slurry it with 8L of deionized water, add 0.385L of RECl3 solution with a concentration of 312g / L (calculated as La2O3), then add 240g of aluminum sulfate, exchange at 90℃ for 1h, then add 75g of ammonium bicarbonate, stir at constant temperature for 0.25h, filter, rinse with 5L of water, and then calcine the filter cake at 600℃ in a 100% steam atmosphere for 2 hours to obtain the dry powder of the one-exchange-one-calcined molecular sieve.

[0179] Take 1000g of dry molecular sieve powder (dry basis weight), slurry it with 6L of deionized water, add 300g of ammonium sulfate, exchange at 75℃ for 1h, filter, rinse with 6L of water, and dry the filter cake to obtain modified molecular sieve DZ1.

[0180] Preparation Example 9

[0181] Following the method of Preparation Example 1, except that in step d, (32g, 0.225mol) ammonium oxalate monohydrate was not added, while the other conditions remained the same, and modified molecular sieve DZ2 was obtained.

[0182] Preparation Example 10

[0183] Following the method of Preparation Example 2, except that in step b, (25.6 g, 0.18 mol) ammonium oxalate monohydrate was not added, while the other conditions remained the same, and modified molecular sieve DZ3 was obtained.

[0184] Preparation Example 11

[0185] Following the method of Preparation Example 4, except that in step b, (25.6 g, 0.18 mol) ammonium oxalate monohydrate and 5 mL of 28% industrial ammonia were not added, and in step d, (18 g, 0.187 mol) ammonium carbonate was not added, with the other conditions remaining the same, the modified molecular sieve DZ4 was obtained.

[0186] Table 1

[0187]

[0188] As can be seen from the data in Table 1, compared with preparation examples 8-11, the modified molecular sieves prepared by the modification process provided by the present invention have higher rare earth utilization, lower sulfate content and higher crystallinity.

[0189] Compared to Preparation Example 5, Preparation Example 1 obtained a modified molecular sieve with lower sulfate content and higher crystallinity by controlling the content of soluble rare earth salts (based on RE2O3) in the Y-type molecular sieve (on a dry basis) within a preferred protection range.

[0190] Compared to Preparation Example 6, Preparation Example 1, by adjusting the amount of the first precipitant to ensure that the content of rare earth ions in the first precipitate is within the preferred protection range, yielded a modified molecular sieve with lower sulfate content and higher crystallinity.

[0191] Compared to Preparation Example 7, Preparation Example 1, by adjusting the amount of the second precipitant to ensure that the content of rare earth ions in the precipitate is within the preferred protection range, yielded a modified molecular sieve with lower sulfate content and higher crystallinity.

[0192] Test Example 1

[0193] The modified molecular sieves (Z1-Z7 and DZ1-DZ4) prepared in Examples 1-11 were subjected to hydrothermal stability tests.

[0194] The test conditions included: 100g (dry basis) of modified molecular sieves (Z1-Z7 and DZ1-DZ4) were compressed into tablets, pulverized into 20-40 mesh particles, aged for 10 hours in a fixed-bed hydrothermal treatment device under 100% water vapor and 800℃ conditions, and then the micro-activity index (MA) was measured on an automatic micro-reaction activity evaluator for catalytic cracking. The test results are listed in Table 2.

[0195] Table 2

[0196] Modified molecular sieves MA, wt% Preparation Example 1 Z1 72 Preparation Example 2 Z2 65 Preparation Example 3 Z3 73 Preparation Example 4 Z4 70 Preparation Example 5 Z5 71 Preparation Example 6 Z6 68 Preparation Example 7 Z7 66 Preparation Example 8 DZ1 60 Preparation Example 9 DZ2 61 Preparation Example 10 DZ3 58 Preparation Example 11 DZ4 61

[0197] As shown in Table 2, compared with Preparation Examples 8-11, the modified molecular sieves prepared in Preparation Examples 1-7 exhibit significantly higher microreactor activity (i.e., higher MA1 values) after aging at 100% water vapor and 800°C for 10 hours. Therefore, the modified molecular sieves prepared using the modification process provided by this invention have better hydrothermal stability and cracking activity.

[0198] Example 1

[0199] (1) The modified molecular sieve Z1, alumina sol, kaolin and water were mixed at 25°C for 1 hour to obtain a slurry with a solid content of 50 wt%; wherein the weight ratio of modified molecular sieve Z1, alumina sol and kaolin was 32:8:60.

[0200] (2) The above slurry was homogenized, spray-molded, and calcined at 450°C for 30 min in sequence. The resulting catalyst precursor was mixed with water to form a slurry containing the catalyst precursor with a solid content of 20 wt%. It was then mixed with ammonium chloride in sequence, filtered, washed with 5 times the amount of water, and dried at 100°C for 12 h to obtain catalytic cracking catalyst C1.

[0201] The weight ratio of ammonium chloride to the slurry containing catalyst precursors, calculated as catalyst precursors, is 5:100.

[0202] In the catalytic cracking catalyst C1, Na, calculated as Na2O, is present. + The content is 0.15 wt%; in the catalytic cracking catalyst C1 on a dry basis, the content of modified molecular sieve Z1 is 32 wt%, the content of binder is 8 wt%, and the content of matrix material is 60 wt%.

[0203] Example 2

[0204] (1) The modified molecular sieve Z2, acidified boehmite, alumina sol, kaolin and water were mixed at 25°C for 1 hour to obtain a slurry with a solid content of 32wt%; wherein the weight ratio of modified molecular sieve Z2, acidified boehmite, alumina sol and kaolin was 32:18:8:42.

[0205] (2) The above slurry was homogenized, spray-molded, and calcined at 470°C for 20 min in sequence. The resulting catalyst precursor was mixed with water to form a slurry containing the catalyst precursor with a solid content of 25 wt%. The slurry was then mixed with ammonium chloride in sequence, filtered, washed with 8 times the amount of water, and dried at 120°C for 8 h to obtain the catalytic cracking catalyst C2.

[0206] The weight ratio of ammonium chloride to the slurry containing catalyst precursors, calculated as catalyst precursors, is 5:100.

[0207] Among them, in the catalytic cracking catalyst C2, Na, calculated as Na2O + The content is 0.14 wt%; in the catalytic cracking catalyst C2 on a dry basis, the content of modified molecular sieve Z2 is 32 wt%, the content of binder is 26 wt%, and the content of matrix material is 42 wt%.

[0208] Example 3

[0209] (1) The modified molecular sieve Z3, acidified boehmite, alumina sol, macroporous aluminosilicate material, kaolin and water were mixed at 25°C for 1 hour to obtain a slurry with a solid content of 36 wt%; wherein the weight ratio of modified molecular sieve Z3, acidified boehmite, alumina sol, macroporous aluminosilicate material and kaolin was 25:15:5.5:4:50.5;

[0210] (2) The above slurry was homogenized, spray-molded, and calcined at 460°C for 35 min in sequence. The resulting catalyst precursor was mixed with water to form a slurry containing the catalyst precursor with a solid content of 20 wt%. The slurry was then mixed with ammonium chloride in sequence, filtered, washed with 5 times the amount of water, and dried at 110°C for 10 h to obtain the catalytic cracking catalyst C3.

[0211] The weight ratio of ammonium chloride to the slurry containing catalyst precursors, calculated as catalyst precursors, is 5:100.

[0212] Among them, in the catalytic cracking catalyst C3, Na, calculated as Na2O + The content is 0.07 wt%; in the catalytic cracking catalyst C3 on a dry basis, the content of modified molecular sieve Z3 is 25 wt%, the content of binder is 20.5 wt%, and the content of matrix material is 54.5 wt%.

[0213] Example 4

[0214] (1) The modified molecular sieve Z4, acidified boehmite, alumina sol, kaolin, halloysite and water were mixed at 25°C for 1 h to obtain a slurry with a solid content of 38 wt%; wherein the weight ratio of modified molecular sieve Z4, acidified boehmite, alumina sol, kaolin and halloysite was 33:25:10:20:12.

[0215] (2) The above slurry was homogenized, spray-molded, and calcined at 450°C for 30 min in sequence. The resulting catalyst precursor was mixed with water to form a slurry containing the catalyst precursor with a solid content of 20 wt%. The slurry was then mixed with ammonium chloride in sequence, filtered, washed with 6 times the amount of water, and dried at 110°C for 10 h to obtain the catalytic cracking catalyst C4.

[0216] The weight ratio of ammonium chloride to the slurry containing catalyst precursors, calculated as catalyst precursors, is 5:100.

[0217] Among them, in the catalytic cracking catalyst C4, Na, calculated as Na2O + The content is 0.11 wt%; in the catalytic cracking catalyst C4 on a dry basis, the content of modified molecular sieve Z4 is 33 wt%, the content of binder is 35 wt%, and the content of matrix material is 32 wt%.

[0218] Examples 5-7

[0219] The method of Example 1 is the same, except that in step (1), the modified molecular sieve Z1 is replaced with modified molecular sieves Z5-Z7 respectively, and the other conditions are the same, so as to obtain catalytic cracking catalysts C5-C7.

[0220] Among them, in the catalytic cracking catalyst C5, Na, calculated as Na2O +The content is 0.15 wt%; in the catalytic cracking catalyst C5 on a dry basis, the content of modified molecular sieve Z5 is 32 wt%, the content of binder is 8 wt%, and the content of matrix material is 60 wt%.

[0221] Among them, in the catalytic cracking catalyst C6, Na, calculated as Na2O + The content is 0.17 wt%; in the catalytic cracking catalyst C6 on a dry basis, the content of modified molecular sieve Z6 is 32 wt%, the content of binder is 8 wt%, and the content of matrix material is 60 wt%.

[0222] Among them, in the catalytic cracking catalyst C7, Na, calculated as Na2O + The content is 0.16 wt%; in the catalytic cracking catalyst C7 on a dry basis, the content of modified molecular sieve Z7 is 32 wt%, the content of binder is 8 wt%, and the content of matrix material is 60 wt%.

[0223] Example 8

[0224] The method of Example 1 is followed, except that in step (1), the weight ratio of modified molecular sieve Z1, alumina sol and kaolin is replaced with 50:14:36, while the other conditions are the same, to obtain catalytic cracking catalyst C8.

[0225] In the catalytic cracking catalyst C8, Na, calculated as Na2O, is present. + The content is 0.18 wt%; in the catalytic cracking catalyst C8 on a dry basis, the content of modified molecular sieve Z1 is 50 wt%, the content of binder is 14 wt%, and the content of matrix material is 36 wt%.

[0226] Example 9

[0227] The method of Example 1 is followed, except that in step (2), the weight ratio of ammonium chloride to slurry containing catalyst precursor, calculated as catalyst precursor, is replaced with 1:100, while the other conditions are the same, to obtain catalytic cracking catalyst C9.

[0228] Among them, in the catalytic cracking catalyst C9, Na, calculated as Na2O + The content is 0.2 wt%; in the catalytic cracking catalyst C9 on a dry basis, the content of modified molecular sieve Z1 is 32 wt%, the content of binder is 8 wt%, and the content of matrix material is 60 wt%.

[0229] Comparative Example 1

[0230] (1) The modified molecular sieve DZ1, acidified boehmite, alumina sol, kaolin and water were mixed at 25°C for 1 hour to obtain a slurry with a solid content of 35wt%; wherein the weight ratio of modified molecular sieve DZ1, acidified boehmite, alumina sol and kaolin was 34:10:8:48.

[0231] (2) The above slurry was homogenized, spray-molded, and calcined at 450°C for 30 min in sequence. The resulting catalyst precursor was mixed with water to form a slurry containing the catalyst precursor with a solid content of 20 wt%. It was then mixed with ammonium chloride in sequence, filtered, washed with 4 times the amount of water, and dried at 105°C for 10 h to obtain the catalytic cracking catalyst DC1.

[0232] The weight ratio of ammonium chloride to the slurry containing catalyst precursors, calculated as catalyst precursors, is 5:100.

[0233] In the catalytic cracking catalyst DC1, Na, calculated as Na2O, is present. + The content is 0.26 wt%; in the catalytic cracking catalyst DC1 on a dry basis, the content of modified molecular sieve DZ1 is 34 wt%, the content of binder is 18 wt%, and the content of matrix material is 48 wt%.

[0234] Comparative Example 2

[0235] (1) The modified molecular sieve DZ2, acidified boehmite, alumina sol, kaolin and water were mixed at 25°C for 1 hour to obtain a slurry with a solid content of 33wt%; wherein the weight ratio of modified molecular sieve DZ2, acidified boehmite, alumina sol and kaolin was 32:15:6:47.

[0236] (2) The above slurry was homogenized, spray-molded, and calcined at 470°C for 30 min in sequence. The resulting catalyst precursor was mixed with water to form a slurry containing the catalyst precursor with a solid content of 20 wt%. It was then mixed with ammonium chloride in sequence, filtered, washed with 4 times the amount of water, and dried at 120°C for 10 h to obtain the catalytic cracking catalyst DC2.

[0237] The weight ratio of ammonium chloride to the slurry containing catalyst precursors, calculated as catalyst precursors, is 5:100.

[0238] In the catalytic cracking catalyst DC2, Na, calculated as Na2O, is present. + The content is 0.23 wt%; in the catalytic cracking catalyst DC2 on a dry basis, the content of modified molecular sieve DZ2 is 32 wt%, the content of binder is 21 wt%, and the content of matrix material is 47 wt%.

[0239] Comparative Example 3

[0240] (1) The modified molecular sieve DZ3, acidified boehmite, alumina sol, kaolin and water were mixed at 25°C for 1 hour to obtain a slurry with a solid content of 38 wt%; wherein the weight ratio of modified molecular sieve DZ3, acidified boehmite, alumina sol and kaolin was 36:13:9:42.

[0241] (2) The above slurry was homogenized, spray-molded, and calcined at 430°C for 45 min in sequence. The catalyst precursor obtained was mixed with water to form a slurry containing the catalyst precursor with a solid content of 20 wt%. It was then mixed with ammonium chloride in sequence, filtered, washed with 6 times the amount of water, and dried at 100°C for 10 h to obtain catalytic cracking catalyst DC3.

[0242] The weight ratio of ammonium chloride to the slurry containing catalyst precursors, calculated as catalyst precursors, is 5:100.

[0243] Among them, in the catalytic cracking catalyst DC3, Na, calculated as Na2O + The content is 0.23 wt%; in the catalytic cracking catalyst DC3 on a dry basis, the content of modified molecular sieve DZ3 is 36 wt%, the content of binder is 22 wt%, and the content of matrix material is 42 wt%.

[0244] Comparative Example 4

[0245] Following the method of Example 1, except that the modified molecular sieve Z1 was replaced with the modified molecular sieve DZ4, while the other conditions remained the same, the catalytic cracking catalyst DC4 was obtained.

[0246] Among them, in the catalytic cracking catalyst DC4, Na, calculated as Na2O + The content is 0.22 wt%; in the catalytic cracking catalyst DC4 on a dry basis, the content of modified molecular sieve DZ4 is 34 wt%, the content of binder is 18 wt%, and the content of matrix material is 48 wt%.

[0247] Test Example 2

[0248] The catalytic cracking catalysts (C1-C9 and DC1-DC4) prepared in Examples 1-9 and Comparative Examples 1-4 were subjected to reaction performance tests. The test conditions included: adding the above-mentioned catalytic cracking catalysts (C1-C9 and DC1-DC4) and Dushanzi wax oil to the ACE heavy oil microreactor and carrying out catalytic cracking (temperature 500℃; catalyst-to-oil ratio 6.5) to obtain catalytic cracking products. The catalytic cracking products included dry gas, liquefied petroleum gas, gasoline, diesel, heavy oil and coke. The weight ratio of catalytic cracking catalyst to Dushanzi wax oil was 6.5:1. The test results are listed in Table 3.

[0249] Table 3

[0250]

[0251]

[0252] Continued from Table 3

[0253]

[0254] Note: 1- The conversion rate of Dushanzi wax oil; 2- The sum of the yields of liquefied petroleum gas, gasoline and diesel.

[0255] As shown in Table 3, compared to Comparative Examples 1-4, the catalytic cracking catalysts prepared in Examples 1-9 contain less Na, calculated as Na₂O. + The content is ≤0.2wt%. At the same time, when it is used to process wax oil, it has excellent wax oil conversion ability and cracking activity, that is, it has a high wax oil conversion rate, gasoline yield, liquefied gas yield and total liquid yield are significantly higher, while diesel and oil slurry yields are significantly lower.

[0256] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A catalytic cracking catalyst, characterized in that, The catalytic cracking catalyst comprises: a modified molecular sieve, a binder, and a matrix material; wherein the modified molecular sieve is prepared by modifying a Y-type molecular sieve, and the modified molecular sieve contains SO4. 2- Content ≤1wt%; In the catalytic cracking catalyst, Na, calculated as Na2O + Content ≤0.2wt%; The modification process includes: a) subjecting the Y-type molecular sieve to rare earth ion exchange to obtain a rare earth ion exchange slurry; b) adding a first precipitant to cause some rare earth ions in the rare earth ion exchange slurry to undergo a first precipitation to obtain a first precipitate slurry; c) subjecting the first precipitate slurry to filtration, first ammonium sulfate exchange, first water washing, and first calcination in sequence to obtain a one-exchange-one-calcination molecular sieve dry powder; d) adding a second precipitant to cause some rare earth ions in the one-exchange-one-calcination molecular sieve dry powder to undergo a second precipitation, followed by a second ammonium sulfate exchange, a second water washing, and a second calcination in sequence to obtain the modified molecular sieve. The first precipitant and the second precipitant are each independently selected from at least one of ammonium oxalate, ammonium carbonate, ammonium bicarbonate, ammonia, urea and ammonium acetate.

2. The catalytic cracking catalyst according to claim 1, wherein, In the catalytic cracking catalyst, on a dry basis, the content of the modified molecular sieve is 15-50 wt%, the content of the binder is 5-38 wt%, and the content of the matrix material is 35-80 wt%.

3. The catalytic cracking catalyst according to claim 2, wherein, In the catalytic cracking catalyst, on a dry basis, the content of the modified molecular sieve is 25-45 wt%, the content of the binder is 8-35 wt%, and the content of the matrix material is 35-60 wt%.

4. The catalytic cracking catalyst according to claim 1, wherein, The silicon-to-aluminum ratio of the Y-type molecular sieve is 2-100; And / or, the Y-type molecular sieve is selected from at least one of NaY molecular sieve, NaHY molecular sieve, NaUSY molecular sieve, NaREHY molecular sieve, and NaREUSY molecular sieve.

5. The catalytic cracking catalyst according to claim 4, wherein, The silicon-to-aluminum ratio of the Y-type molecular sieve is 2-50; And / or, the Y-type molecular sieve is selected from NaY molecular sieve and / or NaHY molecular sieve.

6. The catalytic cracking catalyst according to claim 1, wherein, In step a, the conditions for rare earth ion exchange include: temperature of 25-180℃; pH of 2.8-6.5; and time of 0.3-3.5h. And / or, the rare earth ion exchange process includes: mixing the Y-type molecular sieve with water, and then adding soluble rare earth salts to carry out the rare earth ion exchange; The weight ratio of the Y-type molecular sieve to water is 1:1.5-30. The soluble rare earth salt, calculated as RE2O3, comprises 1-20 wt% of the Y-type molecular sieve on a dry basis. The soluble rare earth salt is selected from chlorates and / or nitrates containing at least one rare earth element.

7. The catalytic cracking catalyst according to claim 6, wherein, In step a, the conditions for rare earth ion exchange include: a temperature of 50-80℃; a pH of 3.5-4.5; and a time of 0.5-1.5h. And / or, during the rare earth ion exchange process, The weight ratio of the Y-type molecular sieve to water is 1:2-5. The soluble rare earth salt, calculated as RE2O3, has a content of 6-16 wt% in the Y-type molecular sieve on a dry basis.

8. The catalytic cracking catalyst according to claim 1, wherein, In step b, the amount of the first precipitant satisfies the molar ratio of rare earth ions with a content of 1-4 wt% in the Y-type molecular sieve after the first precipitation. And / or, the first precipitant is selected from at least one of ammonium oxalate, ammonium carbonate, ammonium bicarbonate and ammonia water; And / or, the conditions for the first precipitation include: a temperature of 25-180°C; The time is 0.1-5 hours.

9. The catalytic cracking catalyst according to claim 8, wherein, In step b, the amount of the first precipitant satisfies the molar ratio of rare earth ions with a content of 1.5-2.5 wt% in the Y-type molecular sieve after the first precipitation. And / or, the conditions for the first precipitation include: a temperature of 50-80°C; The time is 0.1-2 hours.

10. The catalytic cracking catalyst according to claim 1, wherein, In step c, the process of exchanging the first ammonium sulfate includes: exchanging the filtered product with the first ammonium sulfate aqueous solution; The weight ratio of the first ammonium sulfate aqueous solution to the Y-type molecular sieve, calculated as ammonium sulfate, is 5-50:

100. Wherein, the concentration of ammonium sulfate in the first ammonium sulfate aqueous solution is 20-400 g / L; And / or, the conditions for the first ammonium sulfate exchange include: a temperature of 15-150°C; and a time of 0.1-5 h; And / or, in the first water wash, the amount of water used is 1-8 times the weight of the Y-type molecular sieve; And / or, the conditions for the first calcination include: a 100% steam atmosphere; a temperature of 400-700°C; and a time of 0.1-5 hours.

11. The catalytic cracking catalyst according to claim 10, wherein, In step c, the first ammonium sulfate exchange process, The weight ratio of the first ammonium sulfate aqueous solution to the Y-type molecular sieve, calculated as ammonium sulfate, is 10-25:

100. Wherein, the concentration of ammonium sulfate in the first ammonium sulfate aqueous solution is 120-250 g / L; And / or, the conditions for the first ammonium sulfate exchange include: a temperature of 50-80°C; and a time of 0.5-2 hours; And / or, in the first water wash, the amount of water used is 2-5 times the weight of the Y-type molecular sieve; And / or, the conditions for the first calcination include: a temperature of 500-650°C and a time of 0.5-3 hours.

12. The catalytic cracking catalyst according to claim 1, wherein, In step d, the amount of the second precipitant satisfies the molar ratio of rare earth ions with a content of 0.5-3wt% in the dry powder of the one-cross-baked molecular sieve after the second precipitation. And / or, the second precipitant is selected from at least one of ammonium oxalate, ammonium carbonate, ammonium bicarbonate and ammonia water; And / or, the conditions for the second precipitation include: a temperature of 15-40°C; and a time of 0.1-5 h; And / or, the second ammonium sulfate exchange process includes: exchanging the second precipitate product with the second ammonium sulfate aqueous solution; The weight ratio of the second ammonium sulfate aqueous solution (calculated as ammonium sulfate) to the dry powder of the cyclohexane-baked molecular sieve is 5-50:

100. The concentration of ammonium sulfate in the second ammonium sulfate aqueous solution is 20-400 g / L; And / or, the conditions for the second ammonium sulfate exchange include: a temperature of 20-85°C; and a time of 0.1-5 h; And / or, in the second water wash, the amount of water used is 1-8 times the weight of the dry powder of the one-cross-baked molecular sieve; And / or, the conditions for the second calcination include: a 20-100% water vapor atmosphere; a temperature of 400-700°C; and a time of 0.1-10 hours. And / or, prior to the second precipitation, the dry powder of the cross-laminated molecular sieve is mixed with water; The weight ratio of the dry powder of the one-cross-baked molecular sieve to water is 1:1.5-30.

13. The catalytic cracking catalyst according to claim 12, wherein, In step d, the amount of the second precipitant satisfies the molar ratio of rare earth ions with a content of 1-2 wt% in the dry powder of the one-cross-baked molecular sieve after the second precipitation. And / or, the conditions for the second precipitation include: a temperature of 20-30°C; and a time of 0.1-2 h; And / or, during the second ammonium sulfate exchange process, The weight ratio of the second ammonium sulfate aqueous solution (calculated as ammonium sulfate) to the dry powder of the cyclohexane-baked molecular sieve is 10-25:

100. The concentration of ammonium sulfate in the second ammonium sulfate aqueous solution is 120-250 g / L; And / or, the conditions for the second ammonium sulfate exchange include: a temperature of 50-80°C; and a time of 0.1-2 h; And / or, in the second water wash, the amount of water used is 2-5 times the weight of the dry powder of the one-cross-baked molecular sieve; And / or, the conditions for the second calcination include: a temperature of 450-650°C; and a time of 0.5-5 hours; And / or, prior to the second precipitation, the dry powder of the cross-laminated molecular sieve is mixed with water; The weight ratio of the dry powder of the one-cross-baked molecular sieve to water is 1:2-5.

14. The catalytic cracking catalyst according to claim 1, wherein, The binder is selected from at least one of alumina sol, acidified boehmite, acidic silica sol, and phosphoalumina sol; And / or, the matrix material is selected from at least one of kaolin, halloysite, diatomite, sepiolite, macroporous alumina, boehmite, and macroporous aluminosilicate materials.

15. The catalytic cracking catalyst according to any one of claims 1-14, wherein, In the modified molecular sieve, SO4 2- Content ≤0.5wt%; Na, calculated as Na₂O + Content ≤1.2wt%; RE calculated as RE₂O₃ 3+ Content ≥ 5wt%; Crystallinity C / C0 ≥ 55%; And / or, in the catalytic cracking catalyst, Na, calculated as Na₂O + The content is 0.05-0.2wt%.

16. The catalytic cracking catalyst according to claim 15, wherein, In the modified molecular sieve, SO4 2- The content is 0.01-0.45 wt%; Na, calculated as Na₂O + Content ≤1wt%; RE calculated as RE2O3 3+ The content is 6-16 wt%; the crystallinity C / C0 is 55-70%.

17. A method for preparing a catalytic cracking catalyst according to any one of claims 1-14, characterized in that, The preparation method includes the following steps: (1) The modified molecular sieve, binder, matrix material and water are mixed to obtain a slurry; (2) The slurry is homogenized, shaped, and calcined in sequence. The resulting catalyst precursor is subjected to sodium reduction treatment to obtain Na2O. + Catalytic cracking catalyst with a content ≤0.2wt%; The modified molecular sieve is prepared by modifying Y-type molecular sieve, and the modified molecular sieve contains SO4. 2- Content ≤1wt%.

18. The preparation method according to claim 17, wherein, In step (1), the weight ratio of the modified molecular sieve, binder and matrix material is 15-50: 5-38: 35-80; And / or, the solid content of the slurry is 25-50 wt%; And / or, in step (2), the conditions for the third calcination include: a temperature of 400-550℃; and a time of 0.1-5h; And / or, the sodium reduction process includes: sequentially mixing a slurry containing the catalyst precursor and an ammonium salt, filtering, washing with a third water, and drying to obtain the catalytic cracking catalyst; The solid content in the slurry containing the catalyst precursor is 10-40 wt%. The weight ratio of the ammonium salt to the catalyst precursor-containing slurry, based on the catalyst precursor, is 1-10:

100. In the third water wash, the amount of water used is 1-8 times the weight of the catalytic cracking catalyst.

19. The preparation method according to claim 18, wherein, In step (1), the weight ratio of the modified molecular sieve, binder and matrix material is 25-45:8-35:35-60; And / or, the solid content of the slurry is 30-50 wt%; And / or, in step (2), the conditions for the third calcination include: a temperature of 450-500℃; and a time of 0.1-2h; And / or, during the sodium reduction treatment, The solid content in the slurry containing the catalyst precursor is 30-38 wt%. The weight ratio of the ammonium salt to the catalyst precursor-containing slurry, based on the catalyst precursor, is 3-8:

100. In the third water wash, the amount of water used is 1.5-3 times the weight of the catalytic cracking catalyst.

20. A method for processing wax oil, characterized in that, The method includes: catalytically cracking wax oil in the presence of a catalyst to obtain catalytic cracking products; wherein the catalytic cracking products include: dry gas, liquefied petroleum gas, gasoline, diesel, heavy oil, and coke; The catalyst is selected from the catalytic cracking catalysts described in any one of claims 1-16.

21. The method according to claim 20, wherein, The weight ratio of the catalyst to the wax oil is 4-12:

1.

22. The method according to claim 21, wherein, The weight ratio of the catalyst to the wax oil is 6-9:1.

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