Catalytic cracking catalyst, and preparation method therefor and use thereof

Abstract

A catalytic cracking catalyst, and a preparation method therefor and the use thereof. The catalytic cracking catalyst comprises a catalytic cracking active component, wherein the catalytic cracking active component comprises: a rare-earth-modified molecular sieve, a phosphorus oxide and a magnesium oxide. The content of SO4 2- in the rare-earth-modified molecular sieve is less than or equal to 1 wt%, and the crystallinity of the rare-earth-modified molecular sieve is 50-80%; and the rare earth content in the rare-earth-modified molecular sieve is 5-20 wt% calculated by RE2O3. By means of using a rare-earth-modified molecular sieve having a low sulfate radical, high crystallinity, strong acidity and good stability and a phosphorus source and a magnesium source in cooperation, the catalytic cracking catalyst has the characteristics of good activity stability, a high heavy oil conversion rate and a high diesel oil yield, such that the catalyst is particularly suitable for heavy oil catalytic cracking, and during a heavy oil catalytic cracking process, same can exhibit a relatively high catalytic cracking activity, and have a relatively high diesel oil yield.

Description

Catalytic cracking catalyst and its preparation method and application

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Chinese patent application 202310812381.2 filed on July 4, 2023, the contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the field of catalyst preparation, and in particular to a catalytic cracking catalyst and a preparation method thereof, as well as application of the catalytic cracking catalyst in heavy oil catalytic cracking. Background Art

[0004] Catalytic cracking units remain one of the most important components of my country's refining and petrochemical industry, producing approximately 70% of gasoline, 40% of diesel, and 35% of propylene. Diesel's primary use is in diesel engines for vehicles and ships. Compared to gasoline engines, diesel engines offer higher thermal efficiency, greater power, lower fuel consumption, and greater economics, leading some small and even high-performance vehicles to switch to diesel.

[0005] From 2010 to 2020, my country's diesel production generally showed an upward trend followed by a downward trend. In 2017, diesel production increased by 16.417 million tons compared to 2011, reaching a peak of 183.180 million tons. However, diesel consumption in my country exhibits a certain seasonality. The peak season for diesel occurs in spring and autumn, particularly from September to November. This is the busy farming season, the end of coastal fishing moratoriums, and an increase in demand for diesel fuel in the fishing industry. The "plum rain" season ends in southern China, while rainy days decrease in northern China. Infrastructure construction, industrial and mining production, and logistics and transportation all enter a period of active production. During this period, indicators such as the logistics prosperity index and China's water and land transport freight turnover also reach relatively high levels throughout the year. Furthermore, the diesel-to-crude oil price gap is generally higher from September to November each year than in other months, a key indicator of the peak diesel consumption season. In recent years, gasoline sales have been significantly sluggish due to factors such as the pandemic and the Russia-Ukraine war, leading to a continued increase in diesel demand and a significant increase in the diesel-to-gasoline consumption ratio. At the same time, for countries with backward infrastructure such as Africa, the power facilities are very backward and rely entirely on diesel for power generation, and the demand for diesel is usually high.

[0006] In summary, although diesel supply generally exceeds demand, it still has a special market shortage phenomenon, and diesel shortages will occur in different regions and seasons. Therefore, on the basis of efficient conversion of heavy oil, how to increase the yield of catalytic cracking diesel remains an important research topic for oil refiners.

[0007] The fundamental design principle for catalytic cracking diesel catalysts is that they should possess an appropriate acid strength and acid density distribution, possessing strong heavy oil cracking ability to convert heavy oil into diesel while simultaneously inhibiting further cracking of the diesel fraction by strong acids. US4843052, US4940531, and US5248642 primarily utilize modified kaolin to increase catalytic cracking diesel yields. CN1217231 discloses a phosphorus-modified zeolite method for increasing diesel yields. CN1307087 and CN1069513 disclose techniques for increasing diesel yield by combining Y-type zeolite and type-selective zeolite as active catalyst components. CN1861754A discloses a method for increasing diesel yield by treating kaolin microspheres with alkali. CN1683474A discloses a method for increasing diesel yield by modifying in-situ crystallized kaolin microspheres with magnesium.

[0008] All existing patented technologies can improve diesel yield. The mainstream technology is still to regulate the acidity of molecular sieves through elements such as P and Mg to increase diesel yield. However, due to the insufficient activity stability of the active component RE-modified Y-type molecular sieve, the heavy oil conversion capacity of the catalyst is insufficient and the oil slurry increases during the process of regulating the acidity of the molecular sieve with elements such as P and Mg. Therefore, technological innovation is needed to improve the activity stability of the Y-type molecular sieve, thereby improving the activity, stability and heavy oil conversion capacity of the catalytic cracking catalyst and the diesel yield.

[0009] Summary of the Invention

[0010] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a catalytic cracking catalyst comprising a rare earth-modified molecular sieve with low sulfate content, high crystallinity and good stability. The catalyst can maintain a strong heavy oil conversion capacity while improving the diesel yield in the process of regulating the acidity strength of the molecular sieve by elements such as P and Mg. The catalyst is used in the catalytic cracking reaction of heavy oil and has the characteristics of good activity and stability, high heavy oil conversion rate and high diesel yield.

[0011] In order to achieve the above object, the first aspect of the present invention provides a catalytic cracking catalyst, wherein the catalytic cracking catalyst contains a catalytic cracking active component, wherein the catalytic cracking active component contains: a rare earth modified molecular sieve, phosphorus oxide and magnesium oxide; SO4 in the rare earth modified molecular sieve 2- The content is ≤1wt%, the crystallinity of the rare earth modified molecular sieve is 50-80%; the rare earth content in the rare earth modified molecular sieve is 5-20wt% calculated as RE2O3.

[0012] A second aspect of the present invention provides a method for preparing the catalytic cracking catalyst according to the first aspect, the method comprising:

[0013] Mixing and contacting the catalytic cracking active component with a macroporous material source and a clay source in a solution state to obtain a catalyst precursor, optionally forming the catalyst precursor, and then optionally drying and calcining the catalyst precursor;

[0014] Preferably, the preparation method comprises:

[0015] (1) mixing the rare earth modified molecular sieve, phosphorus source and water to form a slurry, then adding a macroporous material source, a binder source and a clay source, mixing and homogenizing, drying and calcining to obtain catalyst solid particles;

[0016] (2) The catalyst solid particles obtained in step (1), water, a magnesium source and optionally an ammonium source are mixed, filtered, washed with water and dried to obtain a catalytic cracking catalyst.

[0017] The third aspect of the present invention provides a use of the catalytic cracking catalyst described in the first aspect in the catalytic cracking of heavy oil.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The catalytic cracking catalyst provided by the present invention is characterized by good activity and stability, high heavy oil conversion rate, and high diesel yield by combining a rare earth modified molecular sieve with low sulfate radicals, high crystallinity, strong acidity, and good stability with phosphorus oxide and magnesium oxide;

[0020] (2) The rare earth modified molecular sieve provided by the present invention is preferably prepared by adding a precipitant (i.e., a first precipitant and a second precipitant) to the Na-type molecular sieve after rare earth ion exchange and before ammonium sulfate exchange to form a precipitate precursor of rare earth oxide with the rare earth ions, thereby avoiding the formation of precipitation with sulfate radicals by free rare earth ions in the exchange system solution, on the surface of the molecular sieve, or in the supercage during the subsequent sodium reduction process by ammonium sulfate exchange, thereby achieving the purpose of reducing sulfate radicals, thereby improving the crystallinity and stability of the molecular sieve while improving the utilization rate of rare earths, so that the molecular sieve has the characteristics of low sulfate radicals, high crystallinity, strong acidity, and good stability. In the subsequent process of regulating the acidity strength of the molecular sieve by elements such as P and Mg, the heavy oil conversion capacity can be maintained while improving the diesel yield;

[0021] (3) The preparation method of the catalytic cracking catalyst provided by the present invention has the characteristics of simple operation, simplified process flow, and easy implementation of industrial production. P and Mg are used to adjust the acidity of the catalyst, thereby controlling the ratio of different reactions in the cracking process, improving the heavy oil conversion capacity of the catalyst and the diesel yield;

[0022] (4) The catalytic cracking catalyst provided by the present invention is particularly suitable for catalytic cracking of heavy oil. During the catalytic cracking of heavy oil, it can not only exhibit high catalytic cracking activity but also obtain a high diesel yield. DETAILED DESCRIPTION

[0023] The endpoints of the ranges and any values ​​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 endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0024] The first aspect of the present invention provides a catalytic cracking catalyst, wherein the catalytic cracking catalyst contains a catalytic cracking active component, wherein the catalytic cracking active component contains: a rare earth modified molecular sieve, phosphorus oxide and magnesium oxide; SO4 in the rare earth modified molecular sieve 2- The content is ≤1wt%, the crystallinity of the rare earth modified molecular sieve is 50-80%; the rare earth content in the rare earth modified molecular sieve is 5-20wt% calculated as RE2O3.

[0025] In the present invention, the catalytic cracking catalyst provided by the present invention is characterized by good activity and stability, high heavy oil conversion rate and high diesel yield by combining a rare earth modified molecular sieve with low sulfate content, high crystallinity, strong acidity and good stability with phosphorus oxide and magnesium oxide.

[0026] In the present invention, unless otherwise specified, the crystallinity parameters are measured by X-ray diffraction.

[0027] According to a preferred embodiment of the present invention, SO4 2- The content is ≤0.5wt%, preferably 0.01-0.45wt%. The above embodiment can improve the crystallinity and stability of rare earth modified molecular sieves, and at the same time improve the utilization rate of rare earth, so that in the process of regulating the acidity strength of molecular sieves by elements such as P and Mg, it can maintain a strong heavy oil conversion capacity while improving the diesel yield, and has the characteristics of good activity stability, high heavy oil conversion rate and high diesel yield. In the present invention, unless otherwise specified, SO4 2- The content parameters were measured by XRF fluorescence method.

[0028] According to a preferred embodiment of the present invention, the sodium content in the rare earth modified molecular sieve is no more than 1.2 wt %, preferably 0.6-1.0 wt %, calculated as Na2O. Using the aforementioned embodiment, a catalytic cracking catalyst with good activity and stability, high heavy oil conversion rate, and high diesel yield can be obtained.

[0029] According to a preferred embodiment of the present invention, the rare earth content of the rare earth-modified molecular sieve, calculated as RE2O3, is 6-18 wt%. This embodiment improves the activity and stability of the rare earth-modified molecular sieve. By regulating the acidity of the molecular sieve with elements such as P and Mg, a catalytic cracking catalyst with excellent activity and stability, high heavy oil conversion, and high diesel yield can be obtained.

[0030] According to a preferred embodiment of the present invention, based on the total weight of the catalytic cracking catalyst, the phosphorus oxide is calculated as P2O5, and the magnesium oxide is calculated as MgO. The catalytic cracking catalyst comprises: 15-30% by weight of a rare earth-modified molecular sieve, 0.5-3% by weight of phosphorus oxide, and 0.2-1.5% by weight of magnesium oxide. By adjusting the content of each component within the aforementioned ranges, a catalytic cracking catalyst with excellent activity and stability, high heavy oil conversion, and high diesel yield can be obtained.

[0031] In the present invention, the rare earth-modified molecular sieve has a wide range of molecular sieve types, and all commonly used molecular sieves can be used in the present invention. According to a preferred embodiment of the present invention, the rare earth-modified molecular sieve is a rare earth-modified Y-type molecular sieve. Using the above embodiment, a catalytic cracking catalyst with good activity and stability, high heavy oil conversion rate, and high diesel yield can be obtained.

[0032] According to a preferred embodiment of the present invention, the catalytic cracking catalyst contains a macroporous material, clay, the catalytic cracking active component and optionally a binder.

[0033] According to a preferred embodiment of the present invention, the macroporous material is selected from macroporous alumina and / or macroporous silicon-alumina material, preferably macroporous silicon-alumina material. Preferably, the specific surface area of ​​the macroporous silicon-alumina material is 400-500m 2 / g, a pore volume of 1-1.5 ml / g, and an average pore diameter of 40-50 nm. The aforementioned embodiment facilitates the diffusion and precracking of heavy oil macromolecules, resulting in a catalytic cracking catalyst with improved activity and stability, higher heavy oil conversion, and higher diesel yield. In the present invention, the specific surface area, pore volume, and average pore diameter of the macroporous material are measured using a low-temperature nitrogen adsorption-desorption method. The instrument used is a TriStar 3020 physicochemical adsorption instrument from Micromeritics, Inc., USA, and the test standard is the corporate standard NB / SH / T0959.

[0034] According to a preferred embodiment of the present invention, the clay is selected from at least one of kaolin, halloysite, porphyrite, diatomite, and vesicle, preferably kaolin. This embodiment can provide thermal protection and active dilution for the rare earth-modified molecular sieve.

[0035] According to a preferred embodiment of the present invention, the binder is selected from at least one of silica, alumina, and phosphorus pentoxide, preferably alumina. In the present invention, the binder is obtained by calcining the binder source. Using this embodiment, a catalytic cracking catalyst with excellent wear resistance can be prepared, ensuring reduced wear during use.

[0036] According to a preferred embodiment of the present invention, the catalytic cracking catalyst comprises a rare earth modified molecular sieve, a macroporous material, a binder, clay, phosphorus oxide, and magnesium oxide. Based on the total weight of the catalytic cracking catalyst, the phosphorus oxide is calculated as P2O5 and the magnesium oxide is calculated as MgO. The catalytic cracking catalyst comprises: 15-30 wt% of the rare earth modified molecular sieve, 2-15 wt% of the macroporous material, 5-30 wt% of the binder, 40-75 wt% of the clay, 0.5-3 wt% of the phosphorus oxide, and 0.2-1.5 wt% of the magnesium oxide. By adopting the above embodiment, by regulating the content of each component within the above range, a catalytic cracking catalyst with good activity and stability, high heavy oil conversion rate, and high diesel yield can be obtained.

[0037] The rare earth modified molecular sieves having the aforementioned characteristics of the present invention can achieve the purpose of the present invention. There is no special requirement for their preparation methods. According to the present invention, a preparation method of a rare earth modified molecular sieve is provided.

[0038] According to a preferred embodiment of the present invention, the preparation method of the rare earth modified molecular sieve comprises the following steps:

[0039] (1) exchanging rare earth ions on a Na-type molecular sieve to obtain a rare earth ion exchange slurry;

[0040] (2) adding a first precipitant to cause a portion of the rare earth ions in the rare earth ion exchange slurry to undergo a first precipitation to obtain a first precipitation slurry;

[0041] (3) the first precipitated slurry is filtered, subjected to a first ammonium sulfate exchange, washed with water, and calcined in sequence to obtain a cross-linked and calcined molecular sieve dry powder;

[0042] (4) adding a second precipitant to cause a second precipitation of some rare earth ions in the cross-linked and roasted molecular sieve dry powder, and then sequentially performing a second ammonium sulfate exchange, a second water washing, and optionally a second roasting to obtain a rare earth modified molecular sieve.

[0043] In the present invention, the rare earth modified molecular sieve is the main active component of the catalytic cracking catalyst, and its performance determines the performance of the catalytic cracking catalyst. The rare earth modified molecular sieve provided by the present invention is prepared by adding a precipitant (i.e., a first precipitant and a second precipitant) to the Na-type molecular sieve after rare earth ion exchange and before ammonium sulfate exchange, to form a precipitate precursor of rare earth oxide with the rare earth ions. This prevents the formation of precipitation between the free rare earth ions in the exchange system solution, on the surface of the molecular sieve, or in the supercage and sulfate during the subsequent sodium reduction process by ammonium sulfate exchange, thereby achieving the purpose of reducing the sulfate content in the molecular sieve. This improves the crystallinity and stability of the molecular sieve while increasing the utilization rate of rare earths, resulting in the molecular sieve having the characteristics of low sulfate, high crystallinity, strong acidity, and good stability. When used as an active component of a catalytic cracking catalyst, the cracking activity and hydrothermal stability of the catalytic cracking catalyst are correspondingly improved. In the subsequent process of regulating the acidity strength of the molecular sieve by elements such as P and Mg, the heavy oil conversion capacity can be maintained while increasing the diesel yield.

[0044] In the present invention, unless otherwise specified, the terms "first" and "second" do not indicate a sequential order or limit the materials or steps. They are used only to distinguish between different steps or materials. For example, the terms "first" and "second" in "first ammonium sulfate exchange" and "second ammonium sulfate exchange" are used only to indicate that they are not the same ammonium sulfate exchange.

[0045] According to a preferred embodiment of the present invention, in step (1), the rare earth ion exchange process includes: mixing the Na-type molecular sieve with water and then adding a soluble rare earth source to perform the rare earth ion exchange.

[0046] According to a preferred embodiment of the present invention, in step (1), the weight ratio of the Na-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 in the range of any two numerical values, preferably 1:(2-5).

[0047] According to a preferred embodiment of the present invention, in step (1), the mass ratio of the soluble rare earth source calculated as RE2O3 to the amount of the Na-type molecular sieve calculated on a dry basis is 1-20:100, for example, 1:100, 4:100, 6:100, 10:100, 14:100, 16:100, 20:100, and any value in the range of any two values, preferably 6-16:100. The above embodiment is more conducive to reducing the sulfate content in the rare earth modified molecular sieve, thereby eliminating the effect of sulfate on the performance of the rare earth modified molecular sieve, and thus improving the crystallinity, stability and catalytic performance of the rare earth modified molecular sieve.

[0048] According to a preferred embodiment of the present invention, in step (1), the rare earth ion exchange conditions include: a temperature of 25-180°C, preferably 50-80°C; and / or a pH of 2.8-6.5, preferably 3.5-4.5; and / or a time of 0.3-3.5h, preferably 0.5-1.5h. The above embodiment can better exchange rare earth ions with Na-type molecular sieves, which is more conducive to reducing the sulfate content in the rare earth modified molecular sieve, thereby eliminating the effect of sulfate on the performance of the rare earth modified molecular sieve, and thus improving the crystallinity, stability and catalytic performance of the rare earth modified molecular sieve.

[0049] The present invention does not particularly limit the type of the Na-type molecular sieve, and the Na-type molecular sieve is well known to those skilled in the art. According to a preferred embodiment of the present invention, in step (1), the silicon-aluminum ratio of the Na-type molecular sieve is 2-100:1, preferably 2-50:1; more preferably, the Na-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, preferably NaY molecular sieve and / or NaHY molecular sieve.

[0050] In the present invention, during the rare earth ion exchange process, the rare earth ions in the soluble rare earth source are completely attached to the surface and internal pores of the Na-type molecular sieve. Therefore, the weight ratio of the Na-type molecular sieve and the soluble rare earth source in terms of RE2O3 on a dry basis is 100:(1-20), preferably 100:(6-16). In the present invention, unless otherwise specified, solubility refers to being readily soluble in water or being readily soluble in water under the action of an auxiliary agent. According to a preferred embodiment of the present invention, in step (1), the soluble rare earth source is selected from chlorates and / or nitrates containing rare earth elements, wherein the rare earth is selected from at least one of lanthanum, cerium and yttrium, preferably lanthanum and / or yttrium.

[0051] According to a preferred embodiment of the present invention, in step (2), the amount of the first precipitant is such that the molar ratio of the rare earth ions in the Na-type molecular sieve is 1-4wt% after the first precipitation; further preferably, the amount of the first precipitant is such that the molar ratio of the rare earth ions in the Na-type molecular sieve is 1.5-2.5wt% after the first precipitation. The above embodiment is more conducive to reducing the content of sulfate in the rare earth modified molecular sieve, thereby eliminating the effect of sulfate on the performance of the rare earth modified molecular sieve, and further improving the crystallinity, stability and catalytic performance of the rare earth modified molecular sieve.

[0052] According to a preferred embodiment of the present invention, in step (2), the conditions of the first precipitation include: a temperature of 25-180° C., preferably 50-80° C.; and / or a time of 0.1-5 hours, preferably 0.1-2 hours. The above embodiment can better promote the first precipitant and rare earth ions to form a precipitate precursor of rare earth oxides, thereby avoiding the formation of precipitation by free rare earth ions and sulfate in the exchange system solution, on the surface of the molecular sieve, or in the supercage during the subsequent ammonium sulfate exchange and sodium reduction process, thereby achieving the purpose of reducing the sulfate content in the molecular sieve, thereby improving the crystallinity and stability of the molecular sieve and the utilization rate of rare earth.

[0053] The present invention does not specifically limit the type of the first precipitant, as long as it can form rare earth oxides with the rare earth ions. According to a preferred embodiment of the present invention, in step (2), the first precipitant is selected from at least one of ammonium carbonate, ammonium bicarbonate, ammonium oxalate, ammonium acetate, ammonia water and urea, and is preferably selected from at least one of ammonium carbonate, ammonium bicarbonate, ammonium oxalate and ammonia water. By adopting the above embodiment, it is possible to preferentially form a precipitate precursor of rare earth oxides with rare earth ions, thereby avoiding the formation of precipitation by free rare earth ions and sulfate in the exchange system solution, on the surface of the molecular sieve or in the supercage during the subsequent ammonium sulfate exchange and sodium reduction process, thereby achieving the purpose of reducing the sulfate content in the molecular sieve, thereby improving the crystallinity and stability of the molecular sieve and the utilization rate of rare earth.

[0054] In the present invention, the purpose of the first ammonium sulfate exchange is to further exchange the Na in the Na type molecular sieve. + According to a preferred embodiment of the present invention, in step (3), the process of the first ammonium sulfate exchange comprises: exchanging the filtered product with the first ammonium sulfate aqueous solution.

[0055] According to a preferred embodiment of the present invention, in step (3), the weight ratio of the first aqueous ammonium sulfate solution to the Na-type molecular sieve in terms of 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 in the range of any two values, preferably 10-25:100. The above embodiment can better exchange the Na in the Na-type molecular sieve. + .

[0056] According to a preferred embodiment of the present invention, in step (3), the concentration of ammonium sulfate in the first aqueous ammonium sulfate solution is 20-400 g / L, for example, 20 g / L, 50 g / L, 80 g / L, 120 g / L, 160 g / L, 200 g / L, 250 g / L, 300 g / L, 400 g / L, and any value in the range of any two values, preferably 120-250 g / L. Using the above embodiment, Na in Na type molecular sieve can be better exchanged. + .

[0057] According to a preferred embodiment of the present invention, in step (3), the conditions for the first ammonium sulfate exchange include: a temperature of 15-150°C, preferably 50-80°C; and / or a time of 0.1-5h, preferably 0.5-2h. The above embodiment can better perform the first ammonium sulfate exchange and further exchange the Na in the Na molecular sieve. + .

[0058] According to a preferred embodiment of the present invention, in step (3), the amount of water used in the first water wash is 1-8 times the weight of the Na-type molecular sieve, for example, 1 times, 2 times, 3 times, 5 times, 7 times, 8 times, and any value in the range of any two values, preferably 2-5 times.

[0059] According to a preferred embodiment of the present invention, in step (3), the conditions of the first calcination include: 100% water vapor atmosphere; and / or temperature of 400-700°C, preferably 500-650°C; and / or time of 0.1-5h, preferably 0.5-3h.

[0060] According to a preferred embodiment of the present invention, in step (4), the amount of the second precipitant is such that the molar ratio of the rare earth ions in the cross-cured molecular sieve dry powder is 0.5-3wt% after the second precipitation; further preferably, the amount of the second precipitant is such that the molar ratio of the rare earth ions in the cross-cured molecular sieve dry powder is 1-2wt% after the second precipitation. The above embodiment can further reduce the sulfate content in the rare earth-modified molecular sieve, thereby better eliminating the effect of sulfate on the performance of the rare earth-modified molecular sieve, and further improving the crystallinity, stability, and catalytic performance of the rare earth-modified molecular sieve.

[0061] According to a preferred embodiment of the present invention, in step (4), the conditions for the second precipitation include: a temperature of 15-40° C., preferably 20-30° C.; and / or a time of 0.1-5 h, preferably 0.1-2 h. The above embodiment can better promote the second precipitant and rare earth ions to form a precipitate precursor of rare earth oxides, thereby avoiding the formation of precipitation by free rare earth ions and sulfate in the exchange system solution, on the surface of the molecular sieve, or in the supercage during the subsequent ammonium sulfate exchange and sodium reduction process, thereby achieving the purpose of reducing the sulfate content in the molecular sieve, thereby improving the crystallinity and stability of the molecular sieve and the utilization rate of rare earth.

[0062] According to a preferred embodiment of the present invention, in step (4), the second precipitant is selected from at least one of ammonium carbonate, ammonium bicarbonate, ammonium oxalate, ammonium acetate, ammonia water, and urea, and is preferably selected from at least one of ammonium carbonate, ammonium bicarbonate, ammonium oxalate, and ammonia water. The aforementioned embodiment can preferentially react with rare earth ions to form a precipitate precursor of a rare earth oxide, thereby avoiding the formation of precipitation by free rare earth ions and sulfate in the exchange system solution, on the surface of the molecular sieve, or in the supercage during the subsequent ammonium sulfate exchange and sodium reduction process, thereby achieving the purpose of reducing the sulfate content in the molecular sieve, thereby improving the crystallinity and stability of the molecular sieve and the utilization rate of the rare earth.

[0063] According to a preferred embodiment of the present invention, in step (4), the second ammonium sulfate exchange process includes: exchanging the second precipitated product with the second ammonium sulfate aqueous solution.

[0064] According to a preferred embodiment of the present invention, in step (4), the weight ratio of the second ammonium sulfate aqueous solution to the cross-calcined molecular sieve dry powder, 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 in the range consisting of any two values, preferably 10-25:100.

[0065] According to a preferred embodiment of the present invention, in step (4), the concentration of ammonium sulfate in the second aqueous ammonium sulfate 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 in the range consisting of any two values, preferably 120-250 g / L.

[0066] According to a preferred embodiment of the present invention, in step (4), the conditions for the second ammonium sulfate exchange include: a temperature of 20-85°C, preferably 50-80°C; and / or a time of 0.1-5h, preferably 0.1-2h. The above embodiment can better perform the second ammonium sulfate exchange and further exchange the Na in the Na molecular sieve. + .

[0067] According to a preferred embodiment of the present invention, in step (4), the amount of water used in the second water washing is 1-8 times the weight of the cross-linked and roasted molecular sieve dry powder, for example, 1 time, 2 times, 3 times, 4 times, 5 times, 8 times, and any value in the range of any two values, preferably 2-5 times.

[0068] According to a preferred embodiment of the present invention, in step (4), the conditions of the second calcination include: 20-100% water vapor atmosphere; and / or temperature of 400-700°C, preferably 450-650°C; and / or time of 0.1-10h, preferably 0.5-5h.

[0069] According to a preferred embodiment of the present invention, in step (4), before the second precipitation, the cross-calcined molecular sieve dry powder and water are mixed.

[0070] According to a preferred embodiment of the present invention, in step (4), the weight ratio of the cross-linked and roasted molecular sieve powder 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 in the range consisting of any two values, preferably 1: (2-5).

[0071] Any catalytic cracking catalyst having the aforementioned characteristics of the present invention can achieve the purpose of the present invention, and there is no special requirement for its preparation method.

[0072] The second aspect of the present invention provides a method for preparing the catalytic cracking catalyst described in the first aspect, the preparation method comprising: mixing and contacting the catalytic cracking active component with a macroporous material source and a clay source in a solution state to obtain a catalyst precursor, optionally shaping it, and then optionally drying and calcining it.

[0073] According to a preferred embodiment of the present invention, the preparation method comprises:

[0074] (1) mixing the rare earth modified molecular sieve, phosphorus source and water to form a slurry, then adding a macroporous material source, a binder source and a clay source, mixing and homogenizing, drying and calcining to obtain catalyst solid particles;

[0075] (2) The catalyst solid particles obtained in step (1), water, a magnesium source and optionally an ammonium source are mixed, filtered, washed with water and dried to obtain a catalytic cracking catalyst.

[0076] In the present invention, the preparation method of the catalytic cracking catalyst provided by the present invention has the characteristics of simple operation, simplified process flow, and easy implementation of industrial production. P and Mg are used to adjust the acidity of the catalyst, thereby controlling the ratio of different reactions in the cracking process, improving the catalyst's heavy oil conversion capacity and diesel yield.

[0077] According to a preferred embodiment of the present invention, in step (1), based on 100 parts by weight of the catalyst dry basis, the phosphorus source is calculated as P2O5, and 15-30 parts of a rare earth-modified molecular sieve, 0.5-3 parts of a phosphorus source, 2-15 parts of a macroporous material source, 5-30 parts of a binder source, and 40-75 parts of a clay source are mixed with water to form a slurry having a solid content of 25-50 wt%. By controlling the contents of the above components within this preferred range using the aforementioned embodiment, a catalytic cracking catalyst having good catalytic activity, high heavy oil conversion, and high diesel yield can be obtained.

[0078] According to a particularly preferred embodiment of the present invention, in step (1), based on 100 parts by weight of the catalyst on a dry basis, the phosphorus source is calculated as P2O5, and 18-27 parts of a rare earth-modified molecular sieve, 0.9-2 parts of a phosphorus source, 3-7 parts of a macroporous material source, 5.5-25 parts of a binder source, and 45-65 parts of a clay source are mixed with water to form a slurry having a solid content of 35-45 wt%. By adopting the above embodiment, the contents of the above components are controlled within a more preferred range, and a catalytic cracking catalyst having better catalytic activity, higher heavy oil conversion rate, and higher diesel yield can be obtained.

[0079] In the present invention, the steps and methods of step (1) of mixing, beating, drying and calcining the rare earth modified molecular sieve, phosphorus source, water, macroporous material source, binder source and clay source have no special requirements and can be carried out using conventional techniques, which will not be described in detail in the present invention.

[0080] The present invention has no special requirements on the various raw materials used, and the purpose of the present invention can be achieved as long as the preparation is carried out according to the above steps of the present invention.

[0081] The present invention has no particular limitation on the type of the phosphorus source, and the phosphorus source is a conventional choice in the art. According to a preferred embodiment of the present invention, in step (1), the phosphorus source is selected from at least one of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, and ammonium phosphate, preferably diammonium hydrogen phosphate.

[0082] According to a preferred embodiment of the present invention, in step (1), the macroporous material source is selected from macroporous alumina and / or macroporous silica-alumina material, preferably macroporous silica-alumina material.

[0083] The present invention does not particularly limit the type of the binder source, and the binder source can be any of various existing binders that can be used in catalytic cracking catalysts. According to a preferred embodiment of the present invention, in step (1), the binder source is selected from at least one of aluminum sol, acidified pseudo-boehmite, acidic silica sol, and phosphate aluminum sol, preferably aluminum sol and / or acidified pseudo-boehmite, more preferably aluminum sol and acidified pseudo-boehmite.

[0084] According to a preferred embodiment of the present invention, the clay source is selected from at least one of kaolin, halloysite, porphyrite, diatomite and vesicle, preferably kaolin.

[0085] The present invention has no special requirements for the drying and calcining steps and methods. Conventional techniques known to those skilled in the art can be employed and are not described in detail herein. Specifically, for example, the drying temperature is 100-150°C for a drying time of 8-15 hours, and the calcining temperature is 400-500°C for a calcining time of 20-50 minutes.

[0086] According to a preferred embodiment of the present invention, in step (2), the weight ratio of water to catalyst solid particles is 0.5-35:1, calculated on a dry basis of catalyst solid particles.

[0087] According to a preferred embodiment of the present invention, in step (2), the magnesium source is calculated as MgO, and the amount of the magnesium source added is 0.2-1.5 wt%, for example, 0.2 wt%, 0.4 wt%, 0.6 wt%, 0.8 wt%, 1.0 wt%, 1.2 wt%, 1.5 wt%, and any value within a range consisting of any two of these values, preferably 0.6-1.2 wt%. Using the aforementioned embodiment, the catalyst is modified by magnesium to have suitable acidity, thereby controlling the ratio of different reactions in the cracking process and improving the heavy oil conversion capacity and diesel yield of the catalytic cracking catalyst.

[0088] The present invention does not specifically limit the type of the magnesium source, and the magnesium source is a conventional choice in the art. According to a preferred embodiment of the present invention, in step (2), the magnesium source is selected from magnesium chloride and / or magnesium nitrate, preferably magnesium chloride. The above embodiment can better modify the catalyst and adjust it to have appropriate acidity, thereby controlling the ratio of different reactions in the cracking process and improving the heavy oil conversion capacity and diesel yield of the catalytic cracking catalyst.

[0089] The present invention has no particular limitation on the type of the ammonium source, and the ammonium source is a conventional choice in the art. According to a preferred embodiment of the present invention, in step (2), the ammonium source is selected from ammonium chloride and / or ammonium nitrate, preferably ammonium chloride.

[0090] According to a preferred embodiment of the present invention, in step (2), the water washing conditions include:

[0091] The temperature is 20-100°C, preferably 25-50°C; and / or the time is 0.1-0.3h, preferably 0.15-0.25h.

[0092] The third aspect of the present invention provides a use of the catalytic cracking catalyst described in the first aspect in the catalytic cracking of heavy oil.

[0093] In the present invention, the catalytic cracking catalyst provided by the present invention is particularly suitable for catalytic cracking of heavy oil. During the catalytic cracking of heavy oil, it can not only exhibit high catalytic cracking activity but also obtain a high diesel yield.

[0094] In the present invention, the catalyst composition is the composition calculated based on the input materials.

[0095] The present invention will be described in detail below through examples.

[0096] The raw materials used in the following examples and comparative examples are as follows:

[0097] NaY molecular sieve: Si / Al ratio 5.1, crystallinity 95%, produced by Changting Catalyst Co., Ltd.

[0098] Soluble rare earth sources: lanthanum chloride, lanthanum nitrate, and yttrium chloride, all industrial products, were collected from the catalyst plant of Lanzhou Petrochemical Company;

[0099] Ammonium sulfate, ammonium oxalate, ammonium carbonate, aqueous ammonia, ammonium chloride, ammonium dihydrogen phosphate, and magnesium chloride were all of analytical grade;

[0100] Pseudo-boehmite (ignition loss 36.7%), kaolin (ignition loss 18.4%), macroporous silica-alumina material (solid content 15.4%, pore volume 1.15ml / g, specific surface area 458m 2 / g, average pore size 43.5nm) solid; aluminum sol, containing 22.6% by weight of aluminum oxide; silica sol, containing 30.5% by weight of silicon oxide, all of which are industrial qualified products.

[0101] In the following examples and comparative examples:

[0102] Determination of SO4 in rare earth modified Y-type molecular sieve by XRF fluorescence method 2-content, Na2O content, RE2O3 content, and Na2O content, P2O5 content and MgO content in catalytic cracking catalyst;

[0103] The crystallinity (C / C0) and silicon-aluminum ratio of rare earth modified Y-type molecular sieve were determined by X-ray diffraction.

[0104] Micro-reaction activity test method: Samples were pre-treated at 800°C and 100% steam for different times. The reaction raw material was Dagang light diesel oil. The reaction temperature was 460°C, the reaction time was 70 seconds, the catalyst loading was 5g, and the catalyst-to-oil weight ratio was 3.2. The total conversion rate was used as the micro-reaction activity.

[0105] Evaluation of Catalytic Cracking Reaction Selectivity: Catalytic Cracking Reaction in ACE Heavy Oil Microreactor

[0106] Selectivity evaluation should be conducted: the catalyst was pre-treated at 800°C and 100% steam for 10 hours. The raw oil for the reaction was the raw oil from the 3 million tons heavy oil catalytic unit of Lanzhou Petrochemical, with a specific composition of 63.2% saturated hydrocarbons, 33.2% aromatic hydrocarbons, and 3.6% colloids; properties included: molecular weight 437g / mol, residual carbon 4.2%; heavy metals included Ca2.2ppm, V4.69ppm, Ni4.42ppm, and Fe4.28ppm; the reaction temperature was 510°C, and the catalyst-oil ratio was 5.

[0107] Example 1

[0108] (1) Preparation of rare earth modified molecular sieves

[0109] (a) 1000 g (dry basis) of NaY molecular sieve was slurried with 5 L of deionized water, and 0.537 L (calculated as La2O3) of 298 g / L LaCl3 solution (La 3+ 0.98 mol) was subjected to rare earth ion exchange (temperature of 80° C., time of 0.5 h) to obtain a rare earth ion exchange slurry; wherein the content of LaCl3 calculated as La2O3 in the NaY molecular sieve on a dry basis was 16 wt%;

[0110] (b) Add (32 g, 0.225 mol) of ammonium oxalate monohydrate to make 2.4 wt% of La in the rare earth ion exchange slurry. 3+ Perform a first precipitation (temperature of 80° C., time of 0.5 h) to obtain a first precipitation slurry;

[0111] (c) The first precipitate slurry was filtered and drained, and 0.833 L of 180 g / L ammonium sulfate aqueous solution was added, exchanged at 60° C. for 1 h, drained, rinsed with 3 L of water, and then calcined at 500° C. in a 100% water vapor atmosphere for 2 h to obtain a cross-linked and calcined molecular sieve dry powder;

[0112] (d) 1000 g (dry basis) of the cross-linked and roasted molecular sieve powder was slurried with 5 L of deionized water, and then 25.6 g, 0.18 mol, of ammonium oxalate monohydrate was added to the cross-linked and roasted molecular sieve powder to make 2 wt% of La 3+ After the second precipitation (temperature 25 ° C, time 0.5 h), 0.6 L of 250 g / L ammonium sulfate aqueous solution was added, exchanged at 80 ° C for 1.5 h, filtered, drained, rinsed with 5 L of water, and calcined at 450 ° C in a 100% water vapor atmosphere for 2 h to obtain rare earth modified Y-type molecular sieve Z1;

[0113] (2) Preparation of catalytic cracking catalyst

[0114] Based on 100 parts of the dry mass of the catalyst, 23 parts by weight of the rare earth modified Y-type molecular sieve Z1 and 1.1 parts by weight of ammonium dihydrogen phosphate (calculated as P2O5) were mixed with water and beaten for 30 minutes. Then, 57.9 parts by weight of kaolin, 6 parts by weight of macroporous silica-alumina material, 6 parts by weight of aluminum sol, and 6 parts by weight of acidified pseudo-boehmite were added and mixed at 25°C for 1 hour to obtain a slurry with a solid content of 48wt%.

[0115] Then, homogenization and spray molding were carried out in sequence, and the obtained microspheres were calcined at 450°C for 25 minutes to obtain a catalytic cracking catalyst precursor;

[0116] 200 g of the catalytic cracking catalyst precursor was mixed with water to form a slurry containing the catalyst precursor having a solid content of 20 wt%, based on the dry catalyst solid particles. Magnesium chloride was then added and mixed, wherein the weight ratio of magnesium chloride (calculated as MgO) to the slurry containing the catalyst precursor was 1:100. The mixture was then filtered and washed with 1 kg of water (5 times the mass of the catalyst precursor) at 25° C. for 0.2 h. The mixture was then dried at 100° C. for 12 h to obtain catalytic cracking catalyst C1.

[0117] Wherein, based on the total weight of the catalytic cracking catalyst, the Na2O in the catalytic cracking catalyst C1 is + The content is 0.14wt%, the phosphorus content calculated as P2O5 is 1.12wt%, and the magnesium content calculated as MgO is 0.92wt%.

[0118] Example 2

[0119] (1) Preparation of rare earth modified molecular sieves

[0120] (a) 1000 g (dry basis) of NaY molecular sieve was slurried with 5 L of deionized water, and 0.358 L of La(NO3)3 solution (La) with a concentration of 280 g / L (calculated as La2O3) was added. 3+0.615 mol) was subjected to rare earth ion exchange (temperature 50° C., time 1.5 h) to obtain a rare earth ion exchange slurry; wherein the content of La(NO3)3 calculated as La2O3 in the NaY molecular sieve on a dry basis was 10 wt%;

[0121] (b) Adding (25.6 g, 0.18 mol) of ammonium oxalate monohydrate can make 2 wt% of La in the above metal ion exchange slurry 3+ Perform a first precipitation (temperature of 50° C., time of 0.5 h) to obtain a first precipitation slurry;

[0122] (c) The first precipitate slurry was filtered and drained, and 1.111 L of 180 g / L ammonium sulfate aqueous solution was added, exchanged at 80° C. for 1 h, drained, rinsed with 3 L of water, and then calcined at 600° C. in a 100% water vapor atmosphere for 2 h to obtain a cross-linked and calcined molecular sieve dry powder;

[0123] (d) 1000 g (dry basis) of the cross-linked and roasted molecular sieve powder was slurried with 5 L of deionized water, and then 13 g, 0.135 mol, of ammonium carbonate was added to increase the La content of the cross-linked and roasted molecular sieve powder to 1.5 wt%. 3+ After the second precipitation (temperature 25 ° C, time 0.5 h), 1.666 L of 120 g / L ammonium sulfate aqueous solution was added, exchanged at 50 ° C for 1 h, filtered, drained, rinsed with 2 L of water, and calcined at 500 ° C in an 80% water vapor atmosphere for 2.5 h to obtain rare earth modified Y-type molecular sieve Z2;

[0124] (2) Preparation of catalytic cracking catalyst

[0125] Based on 100 parts of the dry mass of the catalyst, 27 parts by weight of the rare earth modified Y-type molecular sieve Z2, 1.8 parts by weight of ammonium dihydrogen phosphate (calculated as P2O5) and water were mixed and beaten for 30 minutes, and then 48.7 parts by weight of kaolin, 3 parts by weight of macroporous silica-alumina material, 4.5 parts by weight of aluminum sol, and 15 parts by weight of acidified pseudo-boehmite were added, and mixed at 25°C for 1 hour to obtain a slurry with a solid content of 39wt%, which was then homogenized and spray-formed in sequence. The resulting microspheres were calcined at 460°C for 30 minutes to obtain a catalytic cracking catalyst precursor;

[0126] 200 g of the catalytic cracking catalyst precursor was mixed with water to form a slurry containing the catalyst precursor having a solid content of 25 wt%, based on the dry catalyst solid particles. Magnesium chloride was then added and mixed, wherein the weight ratio of magnesium chloride (calculated as MgO) to the slurry containing the catalyst precursor was 0.65:100. The mixture was then filtered, washed with 1.6 kg of water (8 times the mass of the catalyst precursor) at 30° C. for 0.15 h, and dried at 120° C. for 8 h to obtain catalytic cracking catalyst C2.

[0127] Wherein, based on the total weight of the catalytic cracking catalyst, the Na2O in the catalytic cracking catalyst C2 is + The content is 0.17wt%, the phosphorus content calculated as P2O5 is 1.72wt%, and the magnesium content calculated as MgO is 0.63wt%.

[0128] Example 3

[0129] (1) Preparation of rare earth modified molecular sieves

[0130] (a) 1000 g (dry basis weight) of NaY molecular sieve was slurried with 5 L of deionized water, and 0.407 L of YCl3 solution (Y2O3) with a concentration of 246 g / L was added. 3+ 0.513 mol) was subjected to rare earth ion exchange (temperature 60° C., time 1 h) to obtain a rare earth ion exchange slurry; wherein the content of YCl3 calculated as Y2O3 in the NaY molecular sieve on a dry basis was 5.97 wt%;

[0131] (b) Adding (32 g, 0.225 mol) of ammonium oxalate monohydrate can make 1.7 wt% of Y in the above metal ion exchange slurry 3+ Perform a first precipitation (temperature of 60° C., time of 0.5 h) to obtain a first precipitation slurry;

[0132] (c) The first precipitate slurry was filtered and drained, and 1.389 L of an aqueous solution of ammonium sulfate with a concentration of 180 g / L was added, exchanged at 60° C. for 1.5 h, drained, rinsed with 3 L of water, and then calcined at 650° C. for 2 h in a 100% water vapor atmosphere to obtain a cross-linked and calcined molecular sieve dry powder;

[0133] (d) 1000 g (dry basis) of the cross-linked and roasted molecular sieve powder was slurried with 5 L of deionized water, and then 22.6 g, 0.16 mol, of ammonium oxalate monohydrate was added to increase the Y content of the cross-linked and roasted molecular sieve powder to 1.2 wt%. 3+After the second precipitation (temperature 25 ° C, time 0.5 h), 1.389 L of 180 g / L ammonium sulfate aqueous solution was added, exchanged at 50 ° C for 1 h, filtered, drained, rinsed with 3 L of water, and calcined at 650 ° C in a 60% water vapor atmosphere for 2 h to obtain rare earth modified Y-type molecular sieve Z3;

[0134] (2) Preparation of catalytic cracking catalyst

[0135] Based on 100 parts of the dry mass of the catalyst, 18 parts by weight of the rare earth modified Y-type molecular sieve Z3 and 0.9 parts by weight of ammonium dihydrogen phosphate (calculated as P2O5) were mixed with water and beaten for 30 minutes, and then 53.1 parts by weight of kaolin, 7 parts by weight of macroporous silica-alumina material, 3 parts by weight of aluminum sol, and 18 parts by weight of acidified pseudo-boehmite were added, and mixed at 25°C for 1 hour to obtain a slurry with a solid content of 36wt%, which was then homogenized and spray-formed in sequence. The resulting microspheres were calcined at 470 for 35 minutes to obtain a catalytic cracking catalyst precursor;

[0136] 200 g of the catalytic cracking catalyst precursor was mixed with water to form a slurry containing the catalyst precursor having a solid content of 20 wt%, based on the dry catalyst solid particles. Magnesium chloride was then added and mixed, wherein the weight ratio of magnesium chloride (calculated as MgO) to the slurry containing the catalyst precursor was 1.2:100. The mixture was then filtered and washed with 1 kg of water (5 times the mass of the catalyst precursor) at 35° C. for 0.25 h. The mixture was then dried at 110° C. for 10 h to obtain catalytic cracking catalyst C3.

[0137] Wherein, based on the total weight of the catalytic cracking catalyst, the Na2O in the catalytic cracking catalyst C3 is + The content is 0.10wt%, the phosphorus content calculated as P2O5 is 0.89wt%, and the magnesium content calculated as MgO is 1.13wt%.

[0138] Example 4

[0139] (1) Preparation of rare earth modified molecular sieves

[0140] (a) 1000 g (dry basis) of NaY molecular sieve was slurried with 5 L of deionized water, and 0.43 L (calculated as RE2O3) of a mixed RECl3 solution with a concentration of 326 g / L (the weight ratio of Ce2O3 to La2O3 was 6:4, RE 3+ 0.9287 mol) was subjected to rare earth ion exchange (temperature at 60° C., time for 1 hour) to obtain a rare earth ion exchange slurry; wherein the content of RECl3 calculated as RE2O3 in the NaY molecular sieve on a dry basis was 14 wt%;

[0141] (b) Add 25.6 g, 0.18 mol of ammonium oxalate monohydrate and 5 mL of 28% industrial ammonia water to make 2.4 wt% of RE in the rare earth ion exchange slurry. 3+ Perform a first precipitation (temperature of 60° C., time of 0.5 h) to obtain a first precipitation slurry;

[0142] (c) The first precipitate slurry was filtered and drained, and 1.222 L of an aqueous solution of ammonium sulfate with a concentration of 180 g / L was added, exchanged at 100° C. for 0.5 h, drained, rinsed with 5 L of water, and then calcined at 600° C. in a 100% water vapor atmosphere for 2 h to obtain a cross-linked and calcined molecular sieve dry powder;

[0143] (d) 1000 g (dry basis) of the cross-linked and roasted molecular sieve powder was slurried with 5 L of deionized water, and then 18 g, 0.187 mol, of ammonium carbonate was added to make 1.8 wt% of the RE in the cross-linked and roasted molecular sieve powder. 3+ After the second precipitation (temperature 25 ° C, time 0.5 h), 1 L of 120 g / L ammonium sulfate aqueous solution was added, exchanged at 25 ° C for 1 h, filtered, drained, rinsed with 4 L of water, and calcined at 550 ° C in a 20% water vapor atmosphere for 2 h to obtain rare earth modified Y-type molecular sieve Z4;

[0144] (2) Preparation of catalytic cracking catalyst

[0145] Based on 100 parts of the dry mass of the catalyst, 25 parts by weight of the rare earth modified Y-type molecular sieve Z4, 1.5 parts by weight of ammonium dihydrogen phosphate (calculated as P2O5) and water were mixed and beaten for 30 minutes, and then 50.5 parts by weight of kaolin, 5 parts by weight of macroporous silica-alumina material, 6 parts by weight of aluminum sol, and 12 parts by weight of acidified pseudo-boehmite were added, and mixed at 25°C for 1 hour to obtain a slurry with a solid content of 42wt%, which was then homogenized and spray-formed in sequence. The resulting microspheres were calcined at 450°C for 40 minutes to obtain a catalytic cracking catalyst precursor;

[0146] 200 g of the catalytic cracking catalyst precursor was mixed with water to form a slurry containing the catalyst precursor having a solid content of 20 wt%, based on the dry catalyst solid particles. Magnesium chloride was then added and mixed, wherein the weight ratio of magnesium chloride (calculated as MgO) to the slurry containing the catalyst precursor was 1.2:100. The mixture was then filtered, washed with 1.2 kg of water (the amount of water used for washing was 6 times the mass of the catalyst precursor) at 25° C. for 0.2 h, and dried at 110° C. for 10 h to obtain catalytic cracking catalyst C4.

[0147] Wherein, based on the total weight of the catalytic cracking catalyst, the Na2O in the catalytic cracking catalyst C4 is +The content is 0.18wt%, the phosphorus content calculated as P2O5 is 1.43wt%, and the magnesium content calculated as MgO is 0.85wt%.

[0148] Example 5

[0149] Prepared according to the method of Example 1, except that

[0150] In the process of preparing the rare earth modified molecular sieve, in step (a), 0.537 L (calculated as La2O3) of a LaCl3 solution with a concentration of 298 g / L is replaced by 0.67 L (calculated as La2O3) of a LaCl3 solution with a concentration of 298 g / L, so that the content of LaCl3 calculated as La2O3 in the NaY molecular sieve on a dry basis is 20 wt %, and the other conditions are the same to obtain a rare earth modified Y molecular sieve Z5;

[0151] In the process of preparing the catalytic cracking catalyst, the rare earth modified Y type molecular sieve Z1 is replaced by the rare earth modified Y type molecular sieve Z5, and the other conditions are the same to obtain the catalytic cracking catalyst C5;

[0152] Wherein, based on the total weight of the catalytic cracking catalyst, the Na2O in the catalytic cracking catalyst C5 is + The content is 0.13wt%, the phosphorus content calculated as P2O5 is 1.18wt%, and the magnesium content calculated as MgO is 0.94wt%.

[0153] Example 6

[0154] Prepared according to the method of Example 1, except that

[0155] In the process of preparing rare earth modified molecular sieve, in step (b), (32g, 0.225mol) ammonium oxalate monohydrate was replaced with (12.8g, 0.09mol) ammonium oxalate monohydrate, so that 1wt% of La in the rare earth ion exchange slurry was 3+ The first precipitation was carried out (temperature was 80° C., time was 0.5 h), and other conditions were the same to obtain rare earth modified Y-type molecular sieve Z6.

[0156] In the process of preparing the catalytic cracking catalyst, the rare earth modified Y type molecular sieve Z1 is replaced by the rare earth modified Y type molecular sieve Z6, and the other conditions are the same to obtain the catalytic cracking catalyst C6;

[0157] Wherein, based on the total weight of the catalytic cracking catalyst, the Na2O in the catalytic cracking catalyst C6 is + The content is 0.18wt%, the phosphorus content calculated as P2O5 is 1.10wt%, and the magnesium content calculated as MgO is 0.92wt%.

[0158] Example 7

[0159] Prepared according to the method of Example 1, except that

[0160] In the process of preparing rare earth modified molecular sieve, in step (d), (25.6g, 0.18mol) ammonium oxalate monohydrate was replaced with (6.4g, 0.045mol) ammonium oxalate monohydrate, so that 0.5wt% of La in the above cross-baked molecular sieve dry powder was 3+ A second precipitation was performed (temperature 25°C, time 0.5h), with other conditions being the same, to obtain rare earth modified Y-type molecular sieve Z7;

[0161] In the process of preparing the catalytic cracking catalyst, the rare earth modified Y type molecular sieve Z1 is replaced by the rare earth modified Y type molecular sieve Z7, and the other conditions are the same to obtain the catalytic cracking catalyst C7;

[0162] Wherein, based on the total weight of the catalytic cracking catalyst, the Na2O in the catalytic cracking catalyst C7 is + The content is 0.19wt%, the phosphorus content calculated as P2O5 is 1.17wt%, and the magnesium content calculated as MgO is 0.97wt%.

[0163] Comparative Example 1

[0164] (1) Preparation of rare earth modified molecular sieves

[0165] Prepared according to the method disclosed in CN200610087535.2, specifically comprising:

[0166] Take 1000g (dry basis weight) of NaY molecular sieve, slurry it with 8L of deionized water, add 0.385L (calculated as La2O3) of 312g / L RECl3 solution, then add 240g of aluminum sulfate, exchange it 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 100% water vapor atmosphere for 2h to obtain a cross-calcined molecular sieve dry powder;

[0167] Take 1000 g (dry basis) of the cross-baked molecular sieve powder, slurry it with 6 L of deionized water, add 300 g of ammonium sulfate, exchange it at 75 ° C for 1 hour, filter it, rinse it with 6 L of water, and dry the filter cake to obtain rare earth modified Y-type molecular sieve DZ1;

[0168] (2) Preparation of catalytic cracking catalyst

[0169] Based on 100 parts of the dry mass of the catalyst, 30 parts by weight of the rare earth modified Y-type molecular sieve DZ1, 0.9 parts by weight of ammonium dihydrogen phosphate (calculated as P2O5) and water were mixed and beaten for 30 minutes, and then 52.1 parts by weight of kaolin, 7 parts by weight of aluminum sol, and 10 parts by weight of acidified pseudo-boehmite were added, and mixed at 25°C for 1 hour to obtain a slurry with a solid content of 37wt%, which was then homogenized and spray-formed in sequence. The resulting microspheres were calcined at 440°C for 30 minutes to obtain a catalytic cracking catalyst precursor;

[0170] 200 g of the catalytic cracking catalyst precursor was mixed with water to form a slurry containing the catalyst precursor having a solid content of 20 wt %, based on the dry weight of the catalyst solid particles. Ammonium chloride was then added and mixed, wherein the weight ratio of ammonium chloride to the slurry containing the catalyst precursor was 4:100. The mixture was then filtered, washed with 0.8 kg of water (4 times the mass of the catalyst precursor) at 25° C. for 0.2 h, and dried at 105° C. for 10 h to obtain catalytic cracking catalyst DC1.

[0171] Wherein, based on the total weight of the catalytic cracking catalyst, the Na2O in the catalytic cracking catalyst DC1 is + The content is 0.25wt%, and the phosphorus content calculated as P2O5 is 0.78wt%.

[0172] Comparative Example 2

[0173] (1) Preparation of rare earth modified molecular sieves

[0174] A rare earth modified Y molecular sieve was prepared according to the method of Example 1, except that in step (b), no (32 g, 0.225 mol) ammonium oxalate monohydrate was added. Other conditions were the same to obtain a rare earth modified Y molecular sieve DZ2.

[0175] (2) Preparation of catalytic cracking catalyst

[0176] Based on 100 parts of the dry mass of the catalyst, 28 parts by weight of the rare earth modified Y-type molecular sieve DZ2, 1.5 parts by weight of ammonium dihydrogen phosphate (calculated as P2O5) and water were mixed and beaten for 30 minutes, and then 50.5 parts by weight of kaolin, 5 parts by weight of aluminum sol, and 15 parts by weight of acidified pseudo-boehmite were added, and mixed at 25°C for 1 hour to obtain a slurry with a solid content of 35wt%, which was then homogenized and spray-formed in sequence. The resulting microspheres were calcined at 470°C for 35 minutes to obtain a catalytic cracking catalyst precursor;

[0177] 200 g of the catalytic cracking catalyst precursor was mixed with water to form a slurry containing the catalyst precursor having a solid content of 20 wt%, based on the dry catalyst solid particles. Ammonium chloride was then added and mixed, wherein the weight ratio of ammonium chloride to the slurry containing the catalyst precursor was 3:100. The mixture was then filtered, washed with 0.8 kg of water (4 times the mass of the catalyst precursor) at 25° C. for 0.2 h, and dried at 120° C. for 10 h to obtain catalytic cracking catalyst DC2.

[0178] Wherein, based on the total weight of the catalytic cracking catalyst, the Na2O in the catalytic cracking catalyst DC2 is + The content is 0.22wt%, and the phosphorus content calculated as P2O5 is 1.42wt%.

[0179] Comparative Example 3

[0180] (1) Preparation of rare earth modified molecular sieves

[0181] A rare earth modified Y-type molecular sieve was prepared according to the method of Example 2, except that in step (d), no (25.6 g, 0.18 mol) ammonium oxalate monohydrate was added. Other conditions were the same to obtain a rare earth modified Y-type molecular sieve DZ3;

[0182] (2) Preparation of catalytic cracking catalyst

[0183] Based on 100 parts of the dry mass of the catalyst, 32 parts by weight of the rare earth modified Y-type molecular sieve DZ3, 1.5 parts by weight of ammonium dihydrogen phosphate (calculated as P2O5) and water were mixed and beaten for 30 minutes, and then 45.5 parts by weight of kaolin, 8 parts by weight of aluminum sol, and 13 parts by weight of acidified pseudo-boehmite were added, and mixed at 25°C for 1 hour to obtain a slurry with a solid content of 35wt%, which was then homogenized and spray-formed in sequence. The resulting microspheres were calcined at 430°C for 35 minutes to obtain a catalytic cracking catalyst precursor;

[0184] 200 g of the catalytic cracking catalyst precursor was mixed with water to form a slurry containing the catalyst precursor having a solid content of 20 wt%, based on the dry catalyst solid particles. Ammonium chloride was then added and mixed, wherein the weight ratio of ammonium chloride to the slurry containing the catalyst precursor was 5:100. The mixture was then filtered, washed with 1.2 kg of water (the amount of water used for washing was 6 times the mass of the catalyst precursor) at 25° C. for 0.2 h, and dried at 100° C. for 10 h to obtain catalytic cracking catalyst DC2.

[0185] Wherein, based on the total weight of the catalytic cracking catalyst, the catalytic cracking catalyst

[0186] In DC3, Na2O +The content is 0.20wt%, and the phosphorus content calculated as P2O5 is 1.32wt%.

[0187] Comparative Example 4

[0188] (1) Preparation of rare earth modified molecular sieves

[0189] Prepared according to the method of Example 4, except that in step (b), (25.6 g, 0.18 mol) of ammonium oxalate monohydrate and 5 mL of 28% industrial ammonia water were not added, and in step (d), (18 g, 0.187 mol) of ammonium carbonate was not added. Other conditions were the same to obtain rare earth modified Y-type molecular sieve DZ4;

[0190] (2) Preparation of catalytic cracking catalyst

[0191] Catalytic cracking catalyst DC4 was prepared according to the method of Example 1, except that rare earth modified Y type molecular sieve Z1 was replaced by rare earth modified Y type molecular sieve DZ4, and other conditions were the same;

[0192] Wherein, based on the total weight of the catalytic cracking catalyst, the Na2O in the catalytic cracking catalyst DC4 is + The content is 0.21wt%, the phosphorus content calculated as P2O5 is 1.09wt%, and the magnesium content calculated as MgO is 0.91wt%.

[0193] The physical properties of the rare earth modified molecular sieves (Z1-Z7 and DZ1-DZ4) prepared in Examples 1-7 of the present invention and Comparative Examples 1-4 are listed in Table 1.

[0194] Table 1

[0195] Test Example 1

[0196] The rare earth modified molecular sieves (Z1-Z7 and DZ1-DZ4) prepared in Examples 1-7 and Comparative Examples 1-4 were subjected to a hydrothermal stability test. The test conditions included: 100 g (dry basis) of the rare earth modified molecular sieves (Z1-Z7 and DZ1-DZ4) were respectively tableted and then crushed into 20-40 mesh particles. After aging for 10 h at 800° C. in a fixed bed hydrothermal treatment device with 100% water vapor, the micro-activity index (MA) was measured on a catalytic cracking automatic micro-reaction activity assessor. The test results are listed in Table 2.

[0197] Table 2

[0198] Test Example 2

[0199] The catalytic cracking catalysts (C1-C7 and DC1-DC4) prepared in Examples 1-7 and Comparative Examples 1-4 were tested for reactivity. The test conditions included adding the catalytic cracking catalysts (C1-C7 and DC1-DC4) and feedstock from a 3 million ton heavy oil catalytic unit of Lanzhou Petrochemical to an ACE heavy oil microreactor and conducting catalytic cracking (temperature of 510°C, weight ratio of catalytic cracking catalyst to feedstock from the 3 million ton heavy oil catalytic unit of Lanzhou Petrochemical of 5:1) to obtain catalytic cracking products. The catalytic cracking products included dry gas, liquefied petroleum gas, gasoline, diesel, heavy oil, and coke. The test results are listed in Table 3.

[0200] Table 3

[0201] Note: 1- conversion rate of feedstock oil in Lanzhou Petrochemical's 3 million tons heavy oil catalytic unit; 2- refers to the sum of the yields of liquefied gas, gasoline and diesel.

[0202] The catalytic cracking catalyst provided by the present invention is characterized by good activity and stability, high heavy oil conversion rate, and high diesel yield by combining a rare earth modified molecular sieve with low sulfate content, high crystallinity, strong acidity, and good stability with a phosphorus source and a magnesium source. The catalyst is particularly suitable for catalytic cracking of heavy oil. During the catalytic cracking of heavy oil, it can not only exhibit high catalytic cracking activity but also achieve a high diesel yield.

[0203] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A catalytic cracking catalyst, characterized in that: The catalytic cracking catalyst contains catalytic cracking active components, wherein the catalytic cracking active components contain: rare earth modified molecular sieve, phosphorus oxide and magnesium oxide; SO4 in the rare earth modified molecular sieve 2- The content is ≤1wt%, the crystallinity of the rare earth modified molecular sieve is 50-80%; the rare earth content in the rare earth modified molecular sieve is 5-20wt% calculated as RE2O3.

2. The catalyst according to claim 1, wherein The rare earth modified molecular sieve SO4 2- Content ≤ 0.5wt%; and / or The sodium content in the rare earth modified molecular sieve is not more than 1.2 wt % in terms of Na2O; and / or The rare earth content of the rare earth modified molecular sieve is 6-18 wt % calculated as RE2O3; and / or Based on the total weight of the catalytic cracking catalyst, the phosphorus oxide is calculated as P2O5, and the magnesium oxide is calculated as MgO. The catalytic cracking catalyst contains: 15-30 weight percent of rare earth modified molecular sieve, 0.5-3 weight percent of phosphorus oxide, and 0.2-1.5 weight percent of magnesium oxide.

3. The catalyst according to claim 2, wherein The rare earth modified molecular sieve SO4 2- The content is 0.01-0.45wt%; and / or The sodium content in the rare earth modified molecular sieve is 0.6-1.0 wt % calculated as Na2O.

4. The catalyst according to claim 1, wherein The rare earth modified molecular sieve is a rare earth modified Y type molecular sieve; The catalytic cracking catalyst contains a macroporous material, clay, the catalytic cracking active component and optionally a binder.

5. The catalyst according to claim 4, wherein The macroporous material is selected from macroporous alumina and / or macroporous silicon-alumina material; and / or The clay is selected from at least one of kaolin, halloysite, porphyrite, diatomaceous earth and vesicle; and / or The binder is selected from at least one of silicon dioxide, aluminum oxide and phosphorus pentoxide.

6. The catalyst according to claim 5, wherein The macroporous material is selected from macroporous silicon-aluminum materials; and / or The clay is selected from kaolin; and / or The binder is selected from alumina.

7. The catalyst according to claim 1, wherein The catalytic cracking catalyst contains rare earth modified molecular sieve, macroporous material, binder, clay, phosphorus oxide and magnesium oxide. Based on the total weight of the catalytic cracking catalyst, the phosphorus oxide is calculated as P2O5 and the magnesium oxide is calculated as MgO. The catalytic cracking catalyst contains: 15-30 weight percent of rare earth modified molecular sieve, 2-15 weight percent of macroporous material, 5-30 weight percent of binder, 40-75 weight percent of clay, 0.5-3 weight percent of phosphorus oxide and 0.2-1.5 weight percent of magnesium oxide.

8. The catalyst according to claim 1, wherein The preparation method of the rare earth modified molecular sieve comprises the following steps: (1) exchanging rare earth ions on a Na-type molecular sieve to obtain a rare earth ion exchange slurry; (2) adding a first precipitant to cause a portion of the rare earth ions in the rare earth ion exchange slurry to undergo a first precipitation to obtain a first precipitation slurry; (3) the first precipitation slurry is filtered, subjected to a first ammonium sulfate exchange, subjected to a first water wash, and subjected to a first roasting in sequence to obtain a cross-exchanged and roasted molecular sieve dry powder; (4) adding a second precipitant to cause a second precipitation of some rare earth ions in the cross-calcined molecular sieve dry powder, and then sequentially performing a second ammonium sulfate exchange, a second water washing, and optionally a second calcination to obtain a rare earth modified molecular sieve.

9. The catalyst according to claim 8, wherein In step (1), The rare earth ion exchange process includes: mixing the Na type molecular sieve with water and then adding a soluble rare earth source to perform the rare earth ion exchange.

10. The catalyst according to claim 9, wherein The weight ratio of the Na-type molecular sieve to water is 1:(1.5-30); and / or The mass ratio of the soluble rare earth source calculated as RE2O3 to the amount of the Na-type molecular sieve calculated as dry basis is 1-20:100; and / or The rare earth ion exchange conditions include: Temperature of 25-180°C; and / or pH 2.8-6.5; and / or Time is 0.3-3.5h; and / or The silicon-aluminum ratio of the Na-type molecular sieve is 2-100:1; and / or The soluble rare earth source is selected from chlorates and / or nitrates containing rare earth elements, wherein the rare earth is selected from at least one of lanthanum, cerium and yttrium.

11. The catalyst according to claim 10, wherein The weight ratio of the Na-type molecular sieve to water is 1:(2-5); and / or The mass ratio of the soluble rare earth source calculated as RE2O3 to the amount of the Na-type molecular sieve calculated as dry basis is 6-16:100; and / or The rare earth ion exchange conditions include: The temperature is 50-80°C; and / or pH 3.5-4.5; and / or Time is 0.5-1.5h; and / or The silicon-aluminum ratio of the Na-type molecular sieve is 2-50:1; and / or The Na-type molecular sieve is at least one selected from NaY molecular sieve, NaHY molecular sieve, NaUSY molecular sieve, NaREHY molecular sieve and NaREUSY molecular sieve; and / or The rare earth is selected from lanthanum and / or yttrium.

12. The catalyst according to claim 11, wherein The Na-type molecular sieve is selected from NaY molecular sieve and / or NaHY molecular sieve.

13. The catalyst according to claim 8, wherein In step (2), The amount of the first precipitant is such that the molar ratio of the rare earth ions in the Na-type molecular sieve with a content of 1-4 wt% after the first precipitation is satisfied; and / or The first precipitant is selected from at least one of ammonium carbonate, ammonium bicarbonate, ammonium oxalate, ammonium acetate, ammonia water and urea.

14. The catalyst according to claim 13, wherein The amount of the first precipitant is such that the molar ratio of the rare earth ions in the Na-type molecular sieve is 1.5-2.5wt% after the first precipitation; and / or The conditions of the first precipitation include: Temperature is 25-180℃; and / or The time is 0.1-5h.

15. The catalyst according to claim 14, wherein The conditions of the first precipitation include: The temperature is 50-80°C; and / or Time is 0.1-2h; and / or The first precipitant is selected from at least one of ammonium carbonate, ammonium bicarbonate, ammonium oxalate and ammonia water.

16. The catalyst according to claim 8, wherein In step (3), The first ammonium sulfate exchange process comprises: exchanging the filtered product with the first ammonium sulfate aqueous solution; and / or The amount of water used in the first water washing is 1-8 times the weight of the Na-type molecular sieve; and / or The first calcination conditions include: 100% water vapor atmosphere; and / or A temperature of 400-700°C; and / or The time is 0.1-5h.

17. The catalyst according to claim 16, wherein The weight ratio of the first aqueous ammonium sulfate solution to the Na-type molecular sieve is 5-50:100, calculated as ammonium sulfate; and / or The concentration of ammonium sulfate in the first aqueous ammonium sulfate solution is 20-400 g / L; and / or The conditions of the first ammonium sulfate exchange include: Temperature of 15-150°C; and / or Time is 0.1-5h; and / or The amount of water used in the first water washing is 2-5 times the weight of the Na-type molecular sieve; and / or The first calcination conditions include: 100% water vapor atmosphere; and / or A temperature of 500-650°C; and / or The time is 0.5-3h.

18. The catalyst according to claim 17, wherein The weight ratio of the first aqueous ammonium sulfate solution to the Na-type molecular sieve is 10-25:100, calculated as ammonium sulfate; and / or The concentration of ammonium sulfate in the first aqueous ammonium sulfate solution is 120-250 g / L; and / or The conditions of the first ammonium sulfate exchange include: The temperature is 50-80°C; and / or The time is 0.5-2h.

19. The catalyst according to claim 8, wherein In step (4), The amount of the second precipitant is such that the molar ratio of the rare earth ions in the cross-baked molecular sieve dry powder to 0.5-3 wt% is satisfied by the second precipitate; and / or The second ammonium sulfate exchange process comprises: exchanging the second precipitated product with the second ammonium sulfate aqueous solution; and / or The amount of water used in the second water washing is 1-8 times the weight of the cross-baked molecular sieve dry powder; and / or The second calcination conditions include: 20-100% water vapor atmosphere; and / or A temperature of 400-700°C; and / or Time is 0.1-10h; and / or Before the second precipitation, the cross-calcined molecular sieve dry powder and water are mixed.

20. The catalyst according to claim 19, wherein The amount of the second precipitant is sufficient to meet the molar ratio of 1-2wt% of rare earth ions in the cross-calcined molecular sieve dry powder after the second precipitation; and / or The second precipitant is selected from at least one of ammonium carbonate, ammonium bicarbonate, ammonium oxalate, ammonium acetate, ammonia water and urea; and / or The conditions of the second precipitation include: Temperature of 15-40°C; and / or Time is 0.1-5h; and / or The weight ratio of the second aqueous ammonium sulfate solution to the cross-calcined molecular sieve dry powder is 5-50:100, calculated as ammonium sulfate; and / or The concentration of ammonium sulfate in the second aqueous ammonium sulfate solution is 20-400 g / L; and / or The conditions of the second ammonium sulfate exchange include: Temperature of 20-85°C; and / or Time is 0.1-5h; and / or The amount of water used in the second water washing is 2-5 times the weight of the cross-baked molecular sieve dry powder; and / or The second calcination conditions include: 20-100% water vapor atmosphere; and / or Temperature of 450-650°C; and / or Time is 0.5-5h; and / or The weight ratio of the cross-baked molecular sieve dry powder to water is 1:(1.5-30).

21. The catalyst according to claim 20, wherein The second precipitant is selected from at least one of ammonium carbonate, ammonium bicarbonate, ammonium oxalate and ammonia water; and / or The conditions of the second precipitation include: Temperature of 20-30°C; and / or Time is 0.1-2h; and / or The weight ratio of the second aqueous ammonium sulfate solution to the cross-calcined molecular sieve powder is 10-25:100, calculated as ammonium sulfate; and / or The concentration of ammonium sulfate in the second aqueous ammonium sulfate solution is 120-250 g / L; and / or The conditions of the second ammonium sulfate exchange include: The temperature is 50-80°C; and / or Time is 0.1-2h; and / or The weight ratio of the cross-baked molecular sieve dry powder to water is 1:(2-5).

22. A method for preparing a catalytic cracking catalyst according to any one of claims 1 to 21, characterized in that: The preparation method comprises: The catalytic cracking active component is mixed and contacted with a macroporous material source and a clay source in a solution state to obtain a catalyst precursor, which is optionally shaped, and then optionally dried and calcined.

23. The preparation method according to claim 22, wherein: The preparation method comprises: (1) mixing the rare earth modified molecular sieve, phosphorus source and water to make a slurry, then adding a macroporous material source, a binder source and a clay source to mix and homogenize, dry and calcine to obtain catalyst solid particles; (2) The catalyst solid particles obtained in step (1), water, a magnesium source and optionally an ammonium source are mixed, filtered, washed with water and dried to obtain a catalytic cracking catalyst.

24. The preparation method according to claim 23, wherein: In step (1), Based on 100 parts of dry catalyst mass and phosphorus source as P2O5, 15-30 parts of rare earth modified molecular sieve, 0.5-3 parts of phosphorus source, 2-15 parts of macroporous material source, 5-30 parts of binder source, 40-75 parts of clay source and water are mixed to prepare a slurry with a solid content of 25-50wt%.

25. The preparation method according to claim 24, wherein: Based on 100 parts of the dry basis weight of the catalyst and the phosphorus source as P2O5, 18-27 parts of a rare earth modified molecular sieve, 0.9-2 parts of a phosphorus source, 3-7 parts of a macroporous material source, 5.5-25 parts of a binder source, 45-65 parts of a clay source and water are mixed to prepare a slurry with a solid content of 35-45wt%; and / or The conditions for the calcination include: The temperature is 400-500℃; and / or The time is 20-50 minutes.

26. The preparation method according to claim 25, wherein: The phosphorus source is selected from at least one of diammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate; and / or The macroporous material source is selected from macroporous alumina and / or macroporous silica-alumina materials; and / or The binder source is selected from at least one of aluminum sol, acidified pseudo-boehmite, acidic silica sol and phosphate aluminum sol; and / or The clay source is selected from at least one of kaolin, halloysite, porphyrite, diatomite and vesicle; and / or The conditions for the calcination include: The temperature is 450-480°C; and / or The time is 25-40 minutes.

27. The preparation method according to claim 26, wherein: The phosphorus source is diammonium phosphate; and / or The macroporous material source is selected from macroporous silicon-aluminum materials; and / or The binder source is selected from alumina sol and / or acidified pseudo-boehmite; and / or The clay source is selected from kaolin.

28. The preparation method according to any one of claims 23 to 27, wherein: In step (2), Calculated on a dry basis of catalyst solid particles, magnesium source is calculated as MgO, The weight ratio of water to catalyst solid particles is 0.5-35:1; and / or The amount of magnesium source added is 0.6-1.2wt%; and / or The conditions of the water washing include: Temperature is 20-100℃; and / or The time is 0.1-0.3h.

29. The preparation method according to claim 28, wherein The amount of the magnesium source added is 0.6-1.2wt%; and / or The magnesium source is selected from magnesium chloride and / or magnesium nitrate; and / or The ammonium source is selected from ammonium chloride and / or ammonium nitrate; and / or The conditions of the water washing include: Temperature is 25-50℃; and / or The time is 0.15-0.25h.

30. Use of the catalytic cracking catalyst according to any one of claims 1 to 21 in catalytic cracking of heavy oil.

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