Catalytic cracking catalyst, process for its preparation and use

Abstract

The application provides a catalytic cracking catalyst and a preparation method and application thereof. The raw material of the catalytic cracking catalyst comprises 0.5-20% of modified ZSM-5 molecular sieve, 15-50% of Y-type molecular sieve, 10-55% of clay, 5-30% of an aluminum source, 3-15% of a binder and 0.2-5% of a modified metal element, with the weight of the raw material being 100%. The weight of the modified ZSM-5 molecular sieve, the Y-type molecular sieve, the clay and the pseudo-boehmite is calculated on a dry basis, and the weight of the binder and the modified metal element is calculated as an oxide. The modified ZSM-5 molecular sieve is obtained by modifying a raw ZSM-5 molecular sieve with a first modifier, and the first modifier comprises a titanium source and a phosphorus source. The application further provides a preparation method of the catalytic cracking catalyst and application of the catalytic cracking catalyst in a catalytic cracking process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil refining catalysts, in particular to a catalytic cracking catalyst and a preparation method and application thereof. BACKGROUND

[0002] In the production process of polyolefin industry, the widely used catalyst is mainly Ziegler-Natta catalyst, which is a titanium-based catalyst. For the preparation of titanium-based polyolefin catalyst, for example, CN 102336851 A discloses a propylene polymerization catalyst, which comprises magnesium, titanium, halogen and a mixture of internal electron donor compounds, such as diisobutyl phthalate, diethyl phthalate or di-n-butyl phthalate, and succinate; Chinese patent CN 107434832 B discloses a propylene polymerization catalyst, which mainly consists of alcohol magnesium compound, titanium compound and phosphonate electron donor compound. The common method for preparing titanium-based catalyst at present is: firstly, preparing halogenated magnesium alcohol compound, for example, by co-heating and dissolving halogenated magnesium and alcohol, then high-pressure spraying or high-speed stirring, and solidifying into microspherical particles in a cooling medium, the specific steps are described in CN 1110281 A; then, reacting the halogenated magnesium alcohol compound particles with halogen-containing compounds such as titanium tetrachloride to prepare a magnesium-supported catalyst, during which various promoters can be added for modification. In the above catalyst preparation process, a large amount of titanium tetrachloride is needed, and the excess ratio is large, and the obtained solid catalyst components need to be washed with hydrocarbon solvents (such as hexane) to remove the un-loaded titanium tetrachloride. Therefore, in the production process of polyolefin catalyst, after the separation and precipitation of the catalyst solid, a large amount of catalyst mother liquor containing at least one of titanium tetrachloride, unreacted hydrocarbons, unreacted halogenated alkoxy titanium, and unreacted esters will be produced. A large amount of waste liquid containing titanium tetrachloride is produced in the preparation process of titanium-based polypropylene catalyst, in which the content of titanium tetrachloride is about 80%-95% (by weight), the content of alkoxy titanium complex is about 2%-5%, and the rest is carbon hydride containing hexane and esters, in which hexane accounts for most of the carbon hydride. If the above waste liquid containing titanium tetrachloride is discharged into the environment, it will inevitably cause environmental pollution and resource waste. At present, there is a lack of simple and effective method for recycling and treating waste liquid containing titanium tetrachloride to reduce environmental pollution. Moreover, the thermal stability of the existing ZSM-5 molecular sieve is not high, even after modification by known methods, the thermal stability of the ZSM-5 molecular sieve is still not ideal, which is not conducive to the use of the molecular sieve, especially the application of the molecular sieve as a cracking catalyst.

[0003] Moreover, for the preparation of titanium-containing catalyst, CN 107866211 A discloses a TiO2sol and a catalytic cracking catalyst and their preparation methods, the titanium chloride molar ratio of the TiO2sol is (0.2-0.6):1; and the corrosion rate of the TiO2sol is ≤1 g / m2 The provided TiO2 sol has the characteristics of high viscosity, low corrosion rate and high pH value, which is beneficial to increase the specific surface area of the catalytic cracking catalyst, improve the sphericity of the catalytic cracking catalyst, enhance the activity of the catalytic cracking catalyst, improve the product distribution of the catalytic cracking reaction, and mainly beneficial to the generation of target product gasoline. CN105618107A discloses a preparation method of a catalytic cracking catalyst, which comprises the steps of preparing titanium and / or zirconium modified Y molecular sieve, preparing catalyst slurry and spray drying, and the catalyst has high heavy oil conversion capacity and gasoline yield. However, the above-mentioned catalytic cracking catalyst still needs to further overcome the technical problems of high heavy oil yield, high coke formation and low total liquid yield in the heavy oil cracking process.

[0004] In the prior art, the treatment problem of the waste liquid containing titanium tetrachloride generated in the preparation process of the titanium-based polypropylene catalyst is not involved, and the modified ZSM-5 molecular sieve and the corresponding catalytic cracking catalyst also do not involve reducing the coke formation tendency and reducing the heavy oil yield. Therefore, although there is the recent catalyst technology, it is still necessary to provide a new technology for preparing a catalytic cracking catalyst which has a simple and feasible preparation process and excellent performance. SUMMARY

[0005] In order to solve the above problems, the purpose of the present application is to provide a catalytic cracking catalyst and a preparation method and application thereof. The catalytic cracking catalyst can promote heavy oil conversion, reduce heavy oil yield, produce more ethylene / propylene and other low-carbon olefins while reducing the coke formation tendency, improving the yield of ethylene / propylene and other low-carbon olefins, and has excellent reaction selectivity and use performance.

[0006] In order to achieve the above purpose, the present application provides a catalytic cracking catalyst, the raw materials of which, based on 100% by weight of the catalytic cracking catalyst, include: 0.5%-20% modified ZSM-5 molecular sieve, 15%-50% Y-type molecular sieve, 10%-55% clay, 5%-30% aluminum source, 3%-15% binder, and 0.2%-5% modified metal element; wherein the weight of the modified ZSM-5 molecular sieve, Y-type molecular sieve, clay and aluminum source is calculated on a dry basis, and the weight of the binder and modified metal element is calculated as an oxide; the preparation method of the modified ZSM-5 molecular sieve comprises: mixing the raw material ZSM-5 and the titanium source of the first modifier to form a mixed solution, performing first calcination, or using an impregnation solution containing a titanium source to fully impregnate the raw material ZSM-5 molecular sieve, drying and performing first calcination; mixing the product of the first calcination with a phosphorus source and performing second calcination to obtain the modified ZSM-5 molecular sieve; and the first modifier includes a titanium source and a phosphorus source.

[0007] In the modified ZSM-5 molecular sieve, the titanium source and the phosphorus source in the first modifier can jointly modify the ZSM-5 molecular sieve, and cooperatively improve the acid distribution and the hydrothermal stability in the ZSM-5 molecular sieve, thereby promoting the conversion of heavy oil in a catalytic process involving a catalytic cracking catalyst and reducing the amount of coke.

[0008] In the modified ZSM-5 molecular sieve, the modified ZSM-5 molecular sieve contains 0.2%-25% titanium and 0.2%-6% phosphorus, based on 100% of the weight of the modified ZSM-5 molecular sieve; and the weight of the titanium and the phosphorus is calculated based on the oxides (titanium dioxide and diphosphorus pentoxide), respectively.

[0009] In the modified ZSM-5 molecular sieve, the weight content of the titanium from the first modifier in the modified ZSM-5 molecular sieve is 0.2%-25%, further can be 0.5%-15%, and more further can be 0.5%-6%, based on the oxide of titanium. Specifically, the weight content of the titanium in the modified ZSM-5 molecular sieve can be 0.2%, 0.5%, 1%, 5%, 10%, 15%, 20%, 25%, and the like, and a range with any two of the above specific values as the end points.

[0010] In the modified ZSM-5 molecular sieve, the weight content of the phosphorus in the modified ZSM-5 molecular sieve is 0.2%-6%, further can be 0.5%-6%, based on the oxide of phosphorus. Specifically, the weight content of the phosphorus in the modified ZSM-5 molecular sieve can be 0.2%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, and the like, and a range with any two of the above specific values as the end points.

[0011] In the modified ZSM-5 molecular sieve, in the first modifier, the phosphorus source includes one or a combination of two or more of phosphoric acid, a phosphoric acid salt, phosphorous acid, a phosphorous acid salt, pyrophosphoric acid, a pyrophosphoric acid salt, polyphosphoric acid, a polyphosphoric acid salt, metaphosphoric acid, a metaphosphoric acid salt. Further, the phosphorus source includes one or a combination of two or more of phosphoric acid, ammonium phosphate, dihydrogen ammonium phosphate, dihydrogen ammonium phosphate, magnesium phosphate, aluminum phosphate, phosphorous acid, ammonium phosphite, sodium pyrophosphate, sodium tripolyphosphate, and sodium hexametaphosphate.

[0012] In the modified ZSM-5 molecular sieve, the ZSM-5 molecular sieve can further include a modified metal element, and accordingly, the first modifier can further include a modified metal source; the modified metal element can modify the ZSM-5 molecular sieve to improve the hydrothermal stability, the acidity, and the catalytic reaction performance of the ZSM-5 molecular sieve.

[0013] In some embodiments, the modified metal element from the first modifier can be present in the modified ZSM-5 molecular sieve in an amount of 0-5% by weight, such as greater than 0% and less than or equal to 5%, further such as 0.5-5%, 0-3%, 0.7-3%, etc., based on the oxide of the modified metal element. Specifically, the modified metal element from the first modifier can be present in the modified ZSM-5 molecular sieve in an amount of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc., and ranges defined by any two of the above specific values as endpoints.

[0014] In some embodiments, the modified ZSM-5 molecular sieve can include 0.2-25% of titanium, 0.2-6% of phosphorus, and 0-5% of the modified metal element, based on 100% by weight of the modified ZSM-5 molecular sieve, wherein the titanium, phosphorus, and modified metal element are in the form of oxides.

[0015] In the above method for preparing a ZSM-5 molecular sieve, when the first modifier includes a modified metal source, the modified metal source is typically mixed with the titanium source and the raw ZSM-5 molecular sieve, or can be mixed with the titanium source to form an impregnation solution for impregnating the raw ZSM-5 molecular sieve, thereby avoiding precipitation between the phosphorus source and the metal.

[0016] In the above method for preparing a ZSM-5 molecular sieve, the raw ZSM-5 molecular sieve can have a silica-to-alumina ratio of 15-450. In some embodiments, the raw ZSM-5 molecular sieve can be a ZSM-5 molecular sieve with a high silica-to-alumina ratio. Specifically, the raw ZSM-5 molecular sieve can have a silica-to-alumina ratio of 20-450, 30-450, etc.

[0017] In the above method for preparing a ZSM-5 molecular sieve, the raw ZSM-5 molecular sieve can include a micro-mesoporous ZSM-5 molecular sieve, i.e., a ZSM-5 molecular sieve containing micropores and mesopores. In some embodiments, the mesoporous ZSM-5 molecular sieve can have a mesopore volume of not less than 0.10 mL / g, such as 0.10-0.70 mL / g, 0.10-0.30 mL / g, 0.30-0.70 mL / g.

[0018] In the above method for preparing a ZSM-5 molecular sieve, the raw ZSM-5 molecular sieve can be added in the form of a slurry, which can be formed by dispersing the raw ZSM-5 molecular sieve in water.

[0019] In the above method for preparing ZSM-5 molecular sieve, the pH value of the mixed solution and / or the impregnation solution can be controlled to be 0.5-8, for example, 0.5-3. By controlling the pH value range of the mixed solution and / or the impregnation solution, the present application is advantageous in controlling the distribution of titanium in the ZSM-5 molecular sieve.

[0020] According to a specific embodiment of the present application, the above method for preparing ZSM-5 molecular sieve can further comprise the operation of adjusting the pH value of the titanium source in the first modifier to be 0.5-8, for example, 0.5-3, and then mixing with the raw ZSM-5 molecular sieve. Further, when the first modifier comprises a modified metal source, the method can also comprise the operation of adjusting the pH value of the modified metal source to be 0.5-8, and then mixing with the raw ZSM-5 molecular sieve. By pre-adjusting the pH value of the titanium source and the modified metal source, the de-alumination of the molecular sieve caused by too high acidity of the system when the titanium source and the modified metal source are mixed with the ZSM-5 molecular sieve can be avoided. Moreover, by controlling the pH value range, the distribution of the modified elements such as titanium in the modified ZSM-5 molecular sieve can be regulated. In some specific embodiments, the pH value can be 0.5, 1, 1.5, 1.8, 2, 3, 4, 5, 6, 7, 8, and the like, and the range with any two of the above specific values as the end points.

[0021] In some specific embodiments, the pH value of the mixed solution, the impregnation solution, the titanium source, and the modified metal source can be adjusted by a pH adjusting agent, which comprises a basic substance. The basic substance can comprise one or a combination of two or more of ammonia, ammonium carbonate, ammonium bicarbonate, water glass, magnesium oxide, magnesium hydroxide, and magnesium carbonate.

[0022] According to a specific embodiment of the present application, the above method for preparing ZSM-5 molecular sieve can comprise adjusting the pH value of the titanium source and the modified metal source of the first modifier to be 0.5-8, filtering, and then mixing the obtained filter cake with the raw ZSM-5 molecular sieve.

[0023] In the above method, the mixed solution and / or the impregnation solution can further comprise a dispersant. The dispersant can promote the sufficient dispersion of the metal elements in the modified metal source and titanium, and is advantageous in improving the hydrothermal stability of the modified ZSM-5 molecular sieve.

[0024] In some embodiments, the dispersant can have a mass of 0-20%, such as 0.2-20%, 0-10%, further controllable to 0.3-6% of the mass of the raw ZSM-5 molecular sieve. In some embodiments, the dispersant can have a weight ratio of 0.1%, 0.3%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20% or any range between any two of the above values.

[0025] In some embodiments, the dispersant can include one or a combination of 1,3,5-trimethylbenzene, 1,3,5-triisopropylbenzene, methyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, and polyethylene glycol.

[0026] In the preparation of the modified ZSM-5 molecular sieve, the dispersant can be added at one time or in several times. Specifically, when the dispersant is added at one time, the dispersant can be added to the mixed solution and / or the impregnation solution, that is, the dispersant is added together with the titanium source, the modified metal source, and the raw ZSM-5 molecular sieve, which helps to improve the dispersity of titanium and modified metal elements; alternatively, the dispersant can be added together with the phosphorus source, which can improve the dispersity of phosphorus. When the dispersant is added in several times, part of the dispersant can be added to the mixed solution containing the titanium source, the modified metal source, and the raw ZSM-5 molecular sieve or the impregnation solution containing the titanium source and the modified metal source, and the remaining dispersant can be added together with the phosphorus source, so as to improve the dispersity of titanium, phosphorus, and modified metal elements in the molecular sieve.

[0027] The preparation process of the modified ZSM-5 molecular sieve described above does not have special restrictions on the mixing conditions of the titanium source and the raw ZSM-5 molecular sieve, and the mixing conditions of the product of the first calcination and the phosphorus source, as long as the components are fully mixed. In some embodiments, the mixing temperature of the titanium source and the raw ZSM-5 molecular sieve can be 4-150°C, and the mixing time can be 10 min-2 h. The mixing temperature of the product of the first calcination and the phosphorus source can be 4-150°C, and the mixing time can be 10 min-2 h.

[0028] In the preparation process of the modified ZSM-5 molecular sieve, the temperature of the first calcination is 450°C-650°C, and the time of the first calcination is 1 h-4 h. Specifically, the temperature of the first calcination can be 450°C, 500°C, 550°C, 600°C, 650°C or any range between any two of the above values. The time of the first calcination can be 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h or any range between any two of the above values.

[0029] In the preparation of the modified ZSM-5 molecular sieve, the temperature of the second calcination is 450°C-650°C, and the time of the second calcination is 1h-4h. Specifically, the temperature of the second calcination can be 450°C, 500°C, 550°C, 600°C, 650°C, and the like, and ranges having any two of the above specific values as endpoints. The time of the second calcination is 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, and the like, and ranges having any two of the above specific values as endpoints.

[0030] In the catalytic cracking catalyst described above, the aluminum source includes one or a combination of two or more of pseudoboehmite, amorphous alumina, boehmite, aluminum nitrate, aluminum chloride. In some specific embodiments, the aluminum source can be pseudoboehmite.

[0031] In the catalytic cracking catalyst described above, the clay includes one or a combination of two or more of kaolin, montmorillonite, diatomite, halloysite (also known as metakaolin), sepiolite, bentonite. Further, the clay includes one or a combination of two or more of kaolin, diatomite, halloysite, sepiolite.

[0032] In the catalytic cracking catalyst described above, the Y molecular sieve includes one or a combination of two or more of HY, NH4Y, hydrothermally stabilized Y molecular sieve, silicon tetrachloride vapor phase stabilized Y molecular sieve, rare earth-containing Y-type molecular sieve, phosphorus-modified stabilized Y molecular sieve. Further, the rare earth-containing Y-type molecular sieve includes rare earth-modified stabilized Y molecular sieve and / or phosphorus and rare earth-modified stabilized Y-type molecular sieve.

[0033] In the catalytic cracking catalyst described above, the binder includes one or a combination of two or more of aluminum sol, silicon sol, silica-alumina sol, phosphorus-alumina sol.

[0034] According to specific embodiments of the present application, the raw material of the catalytic cracking catalyst can further include a second modifier, the second modifier including a modified metal source, 0.2%-5% of the modified metal elements contained in the raw material of the catalytic cracking catalyst coming from the second modifier, i.e., 0.2-0.5% being the total amount of the modified metal elements provided by the first modifier and the second modifier.

[0035] In some specific embodiments, in the first modifier and / or the second modifier, the modified metal elements in the modified metal source include one or a combination of two or more of iron, zinc, magnesium, calcium, zirconium, rare earth elements. The rare earth elements can further include one or a combination of two or more of lanthanum, cerium, yttrium elements. The modified metal elements contained in the first modifier and the second modifier can be the same or different.

[0036] In some embodiments, the modifying metal element in the first modifier can include zirconium and / or iron.

[0037] In some embodiments, the modifying metal element in the second modifier can include one or a combination of two or more of rare earth elements, yttrium, magnesium, and cerium.

[0038] According to embodiments of the present application, the modifying metal source includes a metal salt and / or a metal oxide of the modifying metal element. The metal salt can include one or a combination of two or more of chloride, nitrate, carbonate, sulfate, oxalate, acetate. The modifying metal source used in the first modifier and the second modifier can be the same or different.

[0039] According to embodiments of the present application, the second modifier can further include a titanium source. The amount of titanium from the second modifier in the feedstock of the catalytic cracking catalyst, in terms of titanium oxide, can be 0-10%, for example, 0.2-10%. In some embodiments, the amount of titanium from the second modifier in the feedstock of the catalytic cracking catalyst can be 0.2%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, and the like, as well as ranges having any two of the foregoing as endpoints.

[0040] According to embodiments of the present application, the amount of the titanium source in the second modifier, in terms of titanium oxide, can be 0-9.9% of the weight of the feedstock of the catalytic cracking catalyst, for example, greater than 0 and less than 9.9%. In some embodiments, the amount of the titanium source in the second modifier in the feedstock of the catalytic cracking catalyst can be 0.9%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 9.9%, and the like, as well as ranges having any two of the foregoing as endpoints.

[0041] In the above-mentioned first modifier and second modifier, the titanium source refers to a substance containing titanium element, which can specifically include titanium tetrachloride. Further, the titanium source includes a combination of titanium tetrachloride and hexane; in some embodiments, the weight ratio of the titanium tetrachloride and hexane can be (4-34):1, for example, 4:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 34:1, and the like, as well as ranges having any two of the foregoing as endpoints.

[0042] According to embodiments of the present application, the titanium source in the first modifier and / or the second modifier includes a waste liquid containing titanium tetrachloride, which contains titanium tetrachloride and further can contain hydrocarbons such as n-hexane.

[0043] The titanium tetrachloride-containing waste liquid can be specifically a titanium tetrachloride-containing waste liquid obtained in a production process of a titanium-based polyolefin (such as polypropylene) catalyst. The titanium tetrachloride-containing waste liquid contains 80%-95% of titanium tetrachloride, 2%-5% of a titanium alkoxy complex, and the rest is hydrocarbons, based on 100% of the total weight of the titanium tetrachloride-containing waste liquid. The hydrocarbons are liquid at room temperature and mainly contain hexane and esters.

[0044] In the titanium tetrachloride-containing waste liquid, the titanium tetrachloride can be used to modify ZSM-5 molecular sieves; the hexane can promote the uniform distribution of titanium in the ZSM-5 molecular sieves, increase the pore volume of the modified ZSM-5 molecular sieves, and thus improve the diffusion effect of molecules in the modified ZSM-5 molecular sieves and the selectivity of the modified ZSM-5 molecular sieves in catalytic reactions. Moreover, the hydrocarbons such as hexane in the titanium tetrachloride-containing solution can form micropores and mesopores after calcination, which is conducive to improving the pore structure of the catalyst and increasing the catalytic activity.

[0045] In some specific embodiments, the titanium tetrachloride-containing waste liquid can be generated in a preparation process of a titanium-based polypropylene catalyst. The above preparation method can solve the problem of waste liquid treatment, save treatment costs, and avoid environmental pollution by using a large amount of titanium tetrachloride-containing waste liquid generated in the preparation process of the titanium-based polypropylene catalyst as a raw material.

[0046] The titanium source used by the first modifier and the second modifier can be the same or different.

[0047] In the above catalytic cracking catalyst, the raw material of the catalytic cracking catalyst further includes an inorganic oxide carrier, and the inorganic oxide carrier includes one or a combination of two or more of white carbon black, an alumina material containing B acid centers, and a silica-alumina material containing B acid centers. The above alumina material containing B acid centers and the above silica-alumina material containing B acid centers have high pore volume, large specific surface area, bimodal pore distribution, high thermal stability, and high acid content, and contain B acid centers.

[0048] In the above catalytic cracking catalyst, the weight of the inorganic oxide carrier material in terms of oxides accounts for 0-30%, and further can account for 2%-15% of the weight of the raw material of the catalytic cracking catalyst. In some specific embodiments, the weight of the inorganic oxide carrier material in terms of oxides accounts for 1%, 2%, 5%, 10%, 15%, 20%, 25%, 30%, or the like, and a range with any two of the above specific values as endpoints.

[0049] In the catalytic cracking catalyst described above, the raw material of the catalytic cracking catalyst includes 0.5-20% of the modified ZSM-5 molecular sieve on a dry basis, further includes 1-18% of the modified ZSM-5 molecular sieve on a dry basis, based on 100% of the weight of the catalytic cracking catalyst. In some specific embodiments, the modified ZSM-5 molecular sieve on a dry basis accounts for 0.5%, 1%, 5%, 10%, 15%, 18%, 20%, etc. specific values and ranges with any two of the above specific values as endpoints in the weight of the raw material of the catalytic cracking catalyst. In the catalytic cracking catalyst described above, the raw material of the catalytic cracking catalyst includes 15-50% of the Y molecular sieve on a dry basis, further includes 20-45% of the Y molecular sieve on a dry basis, based on 100% of the weight of the catalytic cracking catalyst. In some specific embodiments, the Y molecular sieve on a dry basis accounts for 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc. specific values and ranges with any two of the above specific values as endpoints in the weight of the raw material of the catalytic cracking catalyst.

[0050] In the catalytic cracking catalyst described above, the raw material of the catalytic cracking catalyst includes 10-55% of the clay on a dry basis, based on 100% of the weight of the catalytic cracking catalyst. In some specific embodiments, the clay on a dry basis accounts for 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, etc. specific values and ranges with any two of the above specific values as endpoints in the weight of the raw material of the catalytic cracking catalyst.

[0051] In the catalytic cracking catalyst described above, the raw material of the catalytic cracking catalyst includes 5-30% of the aluminum source on a dry basis, includes 5-25% of the aluminum source on a dry basis, based on 100% of the weight of the catalytic cracking catalyst. In some specific embodiments, the aluminum source on a dry basis accounts for 5%, 10%, 15%, 20%, 25%, 30%, etc. specific values and ranges with any two of the above specific values as endpoints in the weight of the raw material of the catalytic cracking catalyst.

[0052] In the catalytic cracking catalyst described above, the raw material of the catalytic cracking catalyst includes 3-15% of the binder on an oxide basis, based on 100% of the weight of the catalytic cracking catalyst. In some specific embodiments, the binder on an oxide basis accounts for 3%, 5%, 10%, 15%, etc. specific values and ranges with any two of the above specific values as endpoints in the weight of the raw material of the catalytic cracking catalyst.

[0053] In the catalytic cracking catalyst described above, the raw material of the catalytic cracking catalyst includes 10% or less of titanium from the second modifier in terms of oxide, further includes 0.2-10%, 0.5-8% of titanium from the second modifier in terms of oxide, based on 100% by weight of the catalytic cracking catalyst. In some embodiments, the titanium from the second modifier can be present in the catalytic cracking catalyst in an amount of 0.2%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc. in terms of oxide, and ranges defined by any two of the above values as endpoints.

[0054] In the catalytic cracking catalyst described above, the raw material of the catalytic cracking catalyst includes 0.2-5% of modified metal elements in terms of oxide, including 0.5-3% of modified metal elements in terms of oxide, based on 100% by weight of the catalytic cracking catalyst. In some embodiments, the modified metal elements from the second modifier can be present in the catalytic cracking catalyst in an amount of 0.2%, 0.5%, 1%, 2%, 3%, 4%, 5%, etc. in terms of oxide, and ranges defined by any two of the above values as endpoints.

[0055] According to embodiments of the present application, the raw material of the catalytic cracking catalyst described above can have the following composition: 0.5-20% of modified ZSM-5 molecular sieve on a dry basis, 15-50% of Y-type molecular sieve on a dry basis, 10-55% of clay on a dry basis, 5-30% of aluminum source (such as pseudo-boehmite) on a dry basis, 3-15% of binder in terms of oxide, 0.2-5% of modified metal elements (from the second modifier) in terms of oxide, 2-15% of inorganic oxide carrier material in terms of oxide, and 0.2-10% of titanium (from the second modifier) in terms of oxide, based on 100% by weight of the raw material of the catalytic cracking catalyst.

[0056] According to embodiments of the present application, the raw material of the catalytic cracking catalyst described above can have the following composition: 1-18% of modified ZSM-5 molecular sieve on a dry basis, 20-45% of Y-type molecular sieve on a dry basis, 10-55% of clay on a dry basis, 5-25% of aluminum source (such as pseudo-boehmite) on a dry basis, 3-15% of binder in terms of oxide, 2-15% of inorganic oxide carrier material in terms of oxide, 0.5-8% of titanium in terms of oxide, and 0.5-3% of modified metal elements in terms of oxide, based on 100% by weight of the raw material of the catalytic cracking catalyst.

[0057] According to a specific embodiment of the present application, the catalytic cracking catalyst contains titanium which can exist in the form of ions inside and on the surface of the modified ZSM-5 molecular sieve, or in the form of oxides as a carrier in the catalyst.

[0058] The present application also provides a preparation method of the catalytic cracking catalyst, which comprises:

[0059] The modified ZSM-5 molecular sieve, Y molecular sieve, clay, aluminum source, binder and second modifier are mixed to form a raw material slurry, and the raw material slurry is spray-dried and calcined to obtain the catalytic cracking catalyst; wherein the second modifier comprises a modified metal source.

[0060] In the preparation process of the catalytic cracking catalyst, the content of the modified elements (titanium, modified metal elements, etc.) in the catalytic cracking catalyst can be further increased by introducing the second modifier.

[0061] According to a specific embodiment of the present application, the pH value of the titanium source in the second modifier can be 0.5-8. In the preparation process of the catalytic cracking catalyst, the pH value of the titanium source can be adjusted to 0.5-8 first, and then the titanium source is mixed with the modified ZSM-5 molecular sieve. When the second modifier comprises a modified metal source with high acidity (such as iron source, etc.), the pH value of the modified metal source can also be adjusted to 0.5-8 first, and then the modified metal source is mixed with the modified ZSM-5 molecular sieve.

[0062] In some specific embodiments, the pH value of the titanium source and the modified metal source in the second modifier is adjusted by using alkaline substances. The alkaline substances can include one or a combination of two or more of ammonia, ammonium carbonate, ammonium bicarbonate, water glass, magnesium oxide, magnesium hydroxide, and magnesium carbonate.

[0063] According to a specific embodiment of the present application, the preparation method can first adjust the pH value of the titanium source and the modified metal source in the second modifier to 0.5-8, and then filter, so that the obtained filter cake is added to the raw material slurry as the second modifier.

[0064] According to a specific embodiment of the present application, by adjusting the pH value of the second modifier in advance, the dealumination of the modified ZSM-5 molecular sieve caused by the excessively high acidity of the system when the modified ZSM-5 molecular sieve is mixed with the second modifier can be avoided. Moreover, by controlling the pH value range, the distribution of the modified elements such as titanium in the ZSM-5 molecular sieve can be controlled.

[0065] In the preparation method of the catalytic cracking catalyst, the modified ZSM-5 molecular sieve can be added in the form of a slurry, and the volume median particle size (D(v, 0.5)) of the slurry of the modified ZSM-5 molecular sieve can be less than or equal to 4 μm (i.e., 50% of the particles by volume can have a particle size less than or equal to 4 μm). In some embodiments, the modified ZSM-5 molecular sieve can be subjected to sand milling treatment in advance.

[0066] In the preparation method of the catalytic cracking catalyst, the volume median particle size D(v, 0.5) of the raw material slurry (formed by the modified ZSM-5 molecular sieve, Y-type molecular sieve, clay, aluminum source, second modifier, etc.) can be less than or equal to 4 μm. The raw material slurry can be subjected to sand milling treatment before spray drying.

[0067] By sand milling treatment of the ZSM-5 molecular sieve and the raw material slurry and control of the particle size, the molecular sieve can be uniformly dispersed with other raw materials of the catalyst, the wear resistance of the catalytic cracking catalyst obtained therefrom can be improved, and the reaction performance of the catalytic cracking catalyst can be improved.

[0068] According to the embodiments of the present application, the preparation method further comprises subjecting at least one of the binder, the clay, the second modifier, and at least part of the modified metal source to acid treatment with the aluminum source. The acid treatment can acidize and disperse the aluminum source such as pseudo-boehmite, solubilize the aluminum source such as pseudo-boehmite, and have a certain binder effect, thereby improving the wear resistance of the catalytic cracking catalyst.

[0069] According to the embodiments of the present application, the acid used in the acid treatment can include inorganic acid. The inorganic acid can include one or a combination of two or more of hydrochloric acid, sulfuric acid, and nitric acid.

[0070] According to the embodiments of the present application, the temperature of the acid treatment can be 40-90 °C, and the time of the acid treatment can be 0.5-3 h.

[0071] In the preparation method of the catalytic cracking catalyst, the raw material slurry further comprises a pore structure improver, and the pore structure improver can improve the pore structure, specific surface area, and other structural properties of the catalyst.

[0072] In some embodiments, the pore structure improver includes one or a combination of two or more of 1,3,5-trimethylbenzene, 1,3,5-triisopropylbenzene, methyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, and polyethylene glycol.

[0073] In the process for preparing the catalytic cracking catalyst, the weight of the pore structure modifier is 0.1%-10% of the weight of the raw material of the catalytic cracking catalyst, further can be 0.3%-6%, more further can be 0.3%-5%. In some specific embodiments, the weight of the pore structure modifier can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10% and the like specific values and the range with any two of the above specific values as the end point of the catalytic cracking catalyst raw material.

[0074] In the process for preparing the catalytic cracking catalyst, the calcination solidification condition is that the temperature is 350-600℃, further can be 500-570℃; the time of the calcination solidification is 0.1-1h, further can be 1-2h.

[0075] In the process for preparing the catalytic cracking catalyst, in the spray drying process, the temperature of the hearth is 350-550℃, for example 450-550℃, the spray tail gas temperature is 150-300℃, for example 200-300℃. In some specific embodiments, the process of the spray drying can be carried out in the spray tower. The present application controls the sieve distribution of the spray forming catalyst microspheres by controlling the spray forming conditions such as the spray pressure, the nozzle size and the like.

[0076] The present application also provides the application of the above-mentioned catalytic cracking catalyst in the catalytic cracking process. The above-mentioned catalytic cracking catalyst is used in the catalytic cracking process, can promote the conversion of heavy oil, reduce the heavy oil yield, reduce the coking tendency, and at the same time, the low carbon olefin yield is high. In some specific embodiments, the reaction temperature of the catalytic cracking process can be 480-530℃, and the agent oil ratio can be 5-8.

[0077] The beneficial effects of the present application include:

[0078] 1、The catalytic cracking catalyst prepared by the method of the present application using the modified ZSM-5 molecular sieve can promote the conversion of heavy oil in the catalytic cracking process, reduce the heavy oil yield, increase the yield of ethylene / propylene and other low carbon olefins, reduce the coking tendency, improve the yield of low carbon olefins, and has excellent reaction selectivity and use performance.

[0079] 2、The catalytic cracking catalyst provided by the application has simple and feasible preparation process, and the titanium content can be adjusted in a large range. Meanwhile, the performance of the titanium-containing catalytic cracking catalyst is improved: the catalytic cracking catalyst is used in heavy oil catalytic cracking process, can promote the conversion of heavy oil, improve the total liquid yield, reduce the coke formation, and has high low-carbon olefin yield. Further, the preparation raw material of the catalytic cracking catalyst can contain titanium tetrachloride-containing waste liquid, which not only solves the treatment problem of the waste liquid and avoids the pollution of the environment, but also reduces the high treatment cost of the waste liquid. BRIEF DESCRIPTION OF DRAWINGS

[0080] Figure 1 The BJH pore distribution curve of the support material APM-7 and the industrial pseudo-boehmite. DETAILED DESCRIPTION

[0081] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the application, the technical solutions of the application are described in detail as follows, but it cannot be understood as the limitation of the implementable range of the application.

[0082] In the application, the dry basis refers to the state of the material after being calcined at 800℃ for 1h.

[0083] The raw materials used in the examples and comparative examples of the application and their specifications are as follows:

[0084] (1) Titanium tetrachloride-containing waste liquid (hereinafter referred to as: titanium tetrachloride-containing waste liquid) generated in the preparation process of the titanium-based polypropylene catalyst: the waste liquid contains 90% of titanium (calculated as TiCl4), 2-5% of alkoxy titanium complex, and the balance of carbon hydride in the total weight of the waste liquid; the carbon hydride mainly contains hexane and the balance of ester. The waste liquid is provided by Lanzhou Chemical Research Center of Petrochemical Research Institute of China Petroleum.

[0085] Kaolin (ignition loss 29 wt%), halloysite (ignition loss 16.6 wt%), pseudo-boehmite (ignition loss 36 wt%), aluminum sol (containing alumina 21.6 wt%), silica sol (silica concentration 30 wt%), ordinary ZSM-5 molecular sieve (silicon-aluminum ratio 31, mesopore volume 0.04 mL / g), USY molecular sieve (Na2O content 1.2 wt%, not containing rare earth, reduction 4 wt%), GUSY-1 molecular sieve (silicon tetrachloride gas phase ultra-stable molecular sieve, Na2O content 1.3 wt%, RE2O3 content 2.7 wt%, relative crystallinity 55%, cell constant 24.46Å, reduction 4 wt%), REHY molecular sieve (Na2O content 1.5 wt%, RE2O3 content 8.2 wt%, reduction 5 wt%), and rare earth chloride solution (content 289.3 g / L as RE2O3): all are industrial products, and are obtained from the catalyst factory of Lanzhou Petrochemical Company.

[0086] (2) Micro-mesoporous ZSM-5 molecular sieve: Si / Al ratio 30, mesoporous volume 0.29 mL / g, purchased from Dalian;

[0087] (3) Diatomite (loss on ignition 2.6 wt%): industrial product, purchased from Inner Mongolia;

[0088] (4) Titanium tetrachloride, magnesium oxide, magnesium chloride, phosphoric acid (concentration 85%), ammonium dihydrogen phosphate, diammonium hydrogen phosphate, cerium oxide, yttrium nitrate, yttrium chloride, yttrium oxide, iron nitrate (Fe(NO3)3·9H2O), zirconium oxide, zirconium sulfate, 1,3,5-trimethylbenzene, polyethylene glycol, carboxymethyl cellulose: all are chemical reagents; n-hexane: analytical reagent.

[0089] (5) Hydrochloric acid: concentration 36%, chemical reagent; nitric acid: concentration 65-68%, chemical reagent; ammonia water: concentration 18%, chemical reagent.

[0090] (6) The carrier material APM-7 used in the following examples and comparative examples is an active silicon-aluminum material produced by the Catalyst Factory of PetroChina Lanzhou Petrochemical Company. The carrier material APM-7 has B acid centers. The carrier material is a multi-level porous silicon-aluminum material rich in B acid characteristics prepared by using cheap silicon and aluminum sources as raw materials, adjusting the pH value of the system with hydrochloric acid and ammonia water, and through steps such as gelation and temperature aging, in accordance with the preparation method of the B acid-rich multi-level porous material APM-7 described in “Application of B acid-rich multi-level porous material in catalytic cracking catalyst” (Fine Petrochemical Industry, 2019, 36(3): 24-27.), the entire contents of the above document are incorporated herein by reference as part of the specification.

[0091] Figure 1 The BJH pore distribution curves of the carrier material APM-7 and the comparative material (industrial pseudo-boehmite, also known as industrial alumina). Figure 1 It can be seen that APM-7 has two pore channel distributions of mesopores and macropores, and there is a relatively wide pore size distribution between 10-100 nm, while the industrial pseudo-boehmite material only has a single pore distribution between 2-4 nm, and the pore size is 3.4 nm. Table 1 gives the infrared acidity characterization data of the carrier material APM-7 and the industrial pseudo-boehmite (comparative material).

[0092] Table 1

[0093]

[0094] As can be seen from Table 1, the total amount of L acid and B acid of APM-7 is 91.50 μmol / g and 197.36 μmol / g, respectively, and the B / L acid ratio is as high as 2.2. The comparative material only contains L acid centers, and the total amount of L acid is 213.61 μmol / g, which is lower than that of APM-7.

[0095] In the following examples and comparative examples, the content of titanium, phosphorus, modified metal and the like in the modified ZSM-5 molecular sieve is determined by X-ray fluorescence analysis. The crystallinity of ZSM-5 is the relative crystallinity, which is determined by XRD method. The specific surface area retention rate is the ratio of the specific surface area of the modified molecular sieve before aging to the specific surface area after aging multiplied by 100%. The pore volume of the molecular sieve is determined by N2 isothermal adsorption-desorption using a Micromeritics ASAP3000 type automatic physical adsorption instrument.

[0096] In the following examples and comparative examples, the furnace temperature of spray drying is 450℃, and the spray tail gas temperature is 200℃.

[0097] Example 1

[0098] The present example provides a catalytic cracking catalyst, and a preparation method thereof, which comprises:

[0099] 1. Preparation of modified ZSM-5 molecular sieve:

[0100] (1) 1.402 kg of microporous ZSM-5 molecular sieve (dry basis) was added to 4 L of deionized water, stirred uniformly, and then 139 g of waste liquid containing titanium tetrachloride was added, stirred for 0.5 h, to form a slurry containing the molecular sieve, dried at 120℃, and calcined at 500℃ for 1 h; wherein the pH value of the slurry containing the molecular sieve was 1.01;

[0101] (2) The calcined molecular sieve of step (1) was mixed with 4 L of deionized water, 73 g of phosphoric acid was added, stirred uniformly, dried at 120℃, and calcined at 500℃ for 1 h to obtain a titanium-phosphorus modified microporous ZSM-5 molecular sieve Z-1.

[0102] 2. Preparation of catalytic cracking catalyst:

[0103] 1.098 kg of kaolin (dry basis), 0.833 kg of aluminum sol, 72.6 mL of rare earth chloride solution, and 1.52 kg of deionized water were added to a beater tank for beating, then 0.6 kg of pseudo-boehmite (dry basis) was added, stirred for 0.5 h, 91 mL of hydrochloric acid was added, stirred for 2 h, and then acidified at 70℃ for 1.5 h to obtain an intermediate system;

[0104] The 0.84 kg of USY molecular sieve (dry basis), 0.18 kg of titanium-phosphorus modified micro-mesoporous ZSM-5 molecular sieve Z-1 (dry basis), 203 g of yttrium nitrate, 106.7 g of magnesium chloride and 1.52 kg of deionized water are mixed and slurried for 1.5 h, then added to the intermediate system of the first slurry tank, and then 30 g of carboxymethyl cellulose is added and slurried for 2 h. The obtained raw material slurry is subjected to sand milling treatment to make the average particle size D(v, 0.5) of the raw material slurry less than 4 μm, and then spray dried to obtain catalyst microspheres.

[0105] The catalyst microspheres obtained by spray drying are calcined, washed to reduce sodium, and dried to obtain the catalytic cracking catalyst CAT-1 of the present example.

[0106] According to the amount of the raw materials added, the titanium-phosphorus modified ZSM-5 molecular sieve Z-1 contains 3.5% titanium (calculated as oxide) and 3.0% phosphorus (calculated as oxide), and the balance is ZSM-5 molecular sieve.

[0107] The raw material composition of the catalytic cracking catalyst CAT-1 is: 36.6 wt% (dry basis) of kaolin, 20 wt% (dry basis) of pseudo-boehmite, 6 wt% of alumina from aluminum sol, 28 wt% (dry basis) of USY molecular sieve, 6 wt% (dry basis) of titanium-phosphorus modified micro-mesoporous ZSM-5 molecular sieve Z-1, 2 wt% of yttrium oxide from yttrium nitrate, 0.7 wt% of magnesium oxide from magnesium chloride, and 0.7 wt% of rare earth oxide from rare earth chloride solution. The catalyst gelation solid content is 38%. The catalyst gelation solid content is the solid content in the raw material slurry, that is, the ratio of the mass of the obtained solid after spray drying to the mass of the raw material slurry before spray drying.

[0108] Example 2

[0109] The present example provides a catalytic cracking catalyst, and a preparation method thereof.

[0110] 1. Preparation of modified ZSM-5 molecular sieve:

[0111] (1) 1.388 kg of micro-mesoporous ZSM-5 molecular sieve (dry basis) and 15 g of polyethylene glycol are added to 3.5 L of deionized water, stirred uniformly, then 20 g of titanium tetrachloride-containing waste liquid and 103 g of zirconium sulfate are added, stirred for 1.5 h to form a molecular sieve-containing slurry, dried at 100°C, and calcined at 550°C for 1.5 h; wherein the pH value of the molecular sieve-containing slurry is 1.52;

[0112] (2) The calcined molecular sieve of step (1) is mixed with 15 g of polyethylene glycol and 3.5 L of deionized water, 97 g of phosphoric acid is added, stirred uniformly, dried at 100°C, and calcined at 550°C for 1.5 h to obtain titanium-zirconium-phosphorus modified micro-mesoporous ZSM-5 molecular sieve Z-2. 2. Preparation of a catalytic cracking catalyst:

[0113] 1.08 kg of kaolin (dry basis), 0.972 kg of aluminum sol and 1.7 kg of deionized water were added into a beater tank for beating, then 0.54 kg of pseudo-boehmite (dry basis), 155.5 mL of rare earth chloride solution were added, stirred for 1.5 h, 91 mL of hydrochloric acid was added, stirred for 0.5 h, and then acidified at 50 °C for 1 h; an intermediate system was obtained.

[0114] After 0.9 kg of GUSY-1 molecular sieve (dry basis), 60 g of micro-mesoporous ZSM-5 molecular sieve Z-2 (dry basis), 45 g of yttrium chloride (calculated as yttrium oxide) and 1.6 kg of deionized water were mixed and beaten for 0.5 h, they were added into the intermediate system in the beater tank of the first step, then 120 g (dry basis) of carrier material APM-7 and 15 g of polyethylene glycol were added, beaten for 1 h, and the obtained raw material slurry was subjected to sand milling treatment to make the average particle size D(v, 0.5) of the raw material slurry less than 4 μm, and then spray dried to obtain catalyst microspheres.

[0115] The catalyst microspheres obtained by spray drying were calcined, washed to reduce sodium, and dried to obtain the catalytic cracking catalyst CAT-2 of the example.

[0116] According to the amount of raw material added, the ZSM-5 molecular sieve Z-2 modified by titanium, zirconium and phosphorus contained 0.5% titanium (calculated as oxide), 3.0% zirconium (calculated as oxide) and 4.0% phosphorus (calculated as oxide), and the balance was ZSM-5 molecular sieve.

[0117] The raw material composition of the catalytic cracking catalyst CAT-2 was as follows: kaolin 36 wt% (dry basis), pseudo-boehmite 18 wt% (dry basis), aluminum oxide from aluminum sol 7 wt%, GUSY-1 molecular sieve 30 wt% (dry basis), micro-mesoporous ZSM-5 molecular sieve Z-2 2 wt% (dry basis), yttrium oxide from yttrium chloride 1.5 wt%, rare earth oxide from rare earth chloride solution 1.5 wt%, and inorganic oxide carrier material APM-7 (dry basis) 4 wt%, and the catalyst gelation solid content was 36%.

[0118] Example 3

[0119] The example provides a catalytic cracking catalyst, and a preparation method thereof.

[0120] 1. Preparation of modified ZSM-5 molecular sieve:

[0121] (1) Under stirring, 792 g of waste liquid containing titanium tetrachloride, 113.6 g of ferric nitrate, and 110 g of carboxymethyl cellulose were added into 3.6 L of deionized water, stirred for 10 min, and then the pH value was adjusted to 6.51 by using ammonia water. Then, 1.102 kg of ordinary ZSM-5 molecular sieve (dry basis) was added and stirred for 1 h to form a slurry containing the molecular sieve. The slurry was dried at 100 ℃ and calcined at 520 ℃ for 1 h. The pH value of the slurry was 5.66.

[0122] (2) The calcined molecular sieve of step (1), 110 g of carboxymethyl cellulose, and 3.6 L of deionized water were mixed, and 139 g of diammonium hydrogen phosphate was added and stirred uniformly. The mixture was dried at 100 ℃ and calcined at 520 ℃ for 1 h to obtain the titanium-iron-phosphorus modified ZSM-5 molecular sieve Z-3.

[0123] 2. Preparation of a catalytic cracking catalyst:

[0124] 0.45 kg of the titanium-iron-phosphorus modified ZSM-5 molecular sieve Z-3 (dry basis) was added into 1.2 L of deionized water and stirred. The slurry of the molecular sieve Z-3 was subjected to sand milling treatment to have an average particle size D(v, 0.5) of less than 4 μm.

[0125] 0.906 kg of kaolin (dry basis), 1.944 kg of aluminum sol, 15 g of cerium oxide, and 0.97 kg of deionized water were added into a beater tank and beaten. Then, 0.24 kg of pseudo-boehmite (dry basis) was added and stirred for 1 h. Then, 20 mL of nitric acid was added and stirred for 1 h. The mixture was acidified at 50 ℃ for 1.2 h to obtain an intermediate system.

[0126] 0.72 kg of GUSY-1 molecular sieve (dry basis), 0.18 kg of REHY molecular sieve (dry basis), 0.45 kg (dry basis) of the titanium-iron-phosphorus modified ZSM-5 molecular sieve Z-3 slurry having an average particle size D(v, 0.5) of less than 4 μm, 54 g of yttrium oxide, 15 g of magnesium oxide, and 1.11 kg of deionized water were mixed and beaten for 0.5 h. The mixture was added into the beater tank of the first step. Then, 150 g of carboxymethyl cellulose was added and beaten for 1.8 h. The obtained raw material slurry was subjected to sand milling treatment to have an average particle size D(v, 0.5) of less than 4 μm. The raw material slurry was spray dried to obtain catalyst microspheres.

[0127] The catalyst microspheres obtained by spray drying were calcined, washed to reduce sodium, and dried to obtain the catalytic cracking catalyst CAT-3 of the present example.

[0128] According to the calculation of the amount of the raw materials, the titanium-iron-phosphorus modified ZSM-5 molecular sieve Z-3 contained 20.0% of titanium (calculated as an oxide), 1.5% of iron (calculated as an oxide), and 5.0% of phosphorus (calculated as an oxide), and the balance was ZSM-5 molecular sieve.

[0129] The raw material composition of the catalytic cracking catalyst CAT-3 is: 30.2 wt% (dry basis) of kaolin, 8 wt% (dry basis) of pseudo-boehmite, 14 wt% of alumina from aluminum sol, 24 wt% (dry basis) of GUSY-1 molecular sieve, 6 wt% (dry basis) of REHY molecular sieve, 15 wt% (dry basis) of ZSM-5 molecular sieve Z-3, 1.8 wt% of yttrium oxide, 0.5 wt% of cerium oxide, 0.5 wt% of magnesium oxide, and the catalyst gel content is 36%.

[0130] Example 4

[0131] The present embodiment provides a catalytic cracking catalyst, and a preparation method thereof, which comprises the following steps:

[0132] 1. Preparation of modified ZSM-5 molecular sieve:

[0133] (1) 170.6 g of Fe(NO3)3·9H2O and 107 g of titanium tetrachloride-containing waste liquid were weighed and dissolved in a suitable volume of distilled water to prepare a mixed iron nitrate / titanium tetrachloride impregnation solution, and the pH value of the mixed iron nitrate / titanium tetrachloride impregnation solution was 0.56; the mixed impregnation solution was slowly poured into 1.381 kg of ordinary ZSM-5 molecular sieve (dry basis), and constant stirring was carried out to achieve equal volume impregnation; after standing for 12 h, it was placed in a 120℃ oven for drying for 6 h; and then it was calcined in a 540℃ muffle furnace for 4 h to obtain a modified Fe-Ti / ZSM-5 molecular sieve;

[0134] (2) The modified Fe-Ti / ZSM-5 molecular sieve of step (1) was mixed with 3.6 L of deionized water, 73 g of ammonium dihydrogen phosphate was added, and stirring was carried out until uniform, and then it was dried at 120℃ and calcined at 520℃ for 1 h to obtain a titanium-iron-phosphorus modified ZSM-5 molecular sieve Z-4.

[0135] 2. Preparation of catalytic cracking catalyst:

[0136] 1.125 kg of kaolin (dry basis), 0.18 kg of diatomite (dry basis), 0.36 kg of pseudo-boehmite (dry basis), 45 g of zirconium oxide, 207.4 mL of rare earth chloride solution, and 2.24 L of deionized water were added to a beater tank for beating, and stirring was carried out for 1 h, then 48.4 mL of hydrochloric acid was added, and stirring was carried out for 0.5 h, and then it was acidified at 55℃ for 2 h.

[0137] The 0.66 kg of GUSY-1 molecular sieve (dry basis), 0.3 kg of REHY molecular sieve (dry basis), 90 g of titanium-iron-phosphorus modified ZSM-5 molecular sieve Z-4 (dry basis) and 1.67 kg of deionized water were mixed and beaten for 0.5 h, then added into the first beating tank, 180 g of aluminum sol and 9 g of 1,3,5-trimethylbenzene were added, and beaten for 1.5 h. The obtained raw material slurry was subjected to sand milling treatment to make the average particle size D(v, 0.5) of the raw material slurry less than 4 μm, and then spray dried to obtain catalyst microspheres.

[0138] The catalyst microspheres obtained by spray drying were calcined, washed to reduce sodium, and dried to obtain the catalytic cracking catalyst CAT-4 of the example.

[0139] According to the amount of the raw material added, the titanium-iron-phosphorus modified ZSM-5 molecular sieve Z-4 contained 2.7% titanium (calculated as oxide), 2.25% iron (calculated as oxide) and 3.0% phosphorus (calculated as oxide), and the balance was ZSM-5 molecular sieve.

[0140] The raw material composition of the catalytic cracking catalyst CAT-4 was as follows: 37.5 wt% (dry basis) of kaolin, 6 wt% (dry basis) of diatomite, 12 wt% (dry basis) of pseudo-boehmite, 6 wt% of alumina from aluminum sol, 1.5 wt% of zirconia, 22 wt% (dry basis) of GUSY-1 molecular sieve, 10 wt% (dry basis) of REHY molecular sieve, 3 wt% (dry basis) of modified ZSM-5 molecular sieve Z-4, 2 wt% of rare earth oxide from rare earth chloride solution, and the catalyst gelation solid content was 35%.

[0141] Example 5

[0142] The example provides a catalytic cracking catalyst, and the preparation method is as follows:

[0143] 30 g of magnesium oxide was added into 1.8 L of deionized water, stirred, 475 g of waste liquid containing titanium tetrachloride was added, and the pH value was adjusted to 7 with ammonia water, and then filtered to obtain a titanium-magnesium-containing filter cake A.

[0144] 0.45 kg of kaolin (dry basis), 0.18 kg of halloysite (dry basis), 0.417 kg of aluminum sol and 2.54 kg of deionized water were added into a beating tank and beaten, then 0.75 kg of pseudo-boehmite (dry basis) was added, stirred for 1 h, 101 mL of hydrochloric acid was added, stirred for 0.5 h, and then acidified at 55°C for 2 h.

[0145] A mixture of 1.05 kg of GUSY-1 molecular sieve (dry basis), 30 g of the phosphorus-titanium modified micro-mesoporous ZSM-5 molecular sieve Z-1 prepared in Example 1 (dry basis), 60 g of yttrium oxide and 1.81 kg of deionized water was mixed and beaten for 0.5 h, and then added into the first beating tank. Then, 600 g of silica sol, 210 g of the above-mentioned filter cake A containing titanium and magnesium (dry basis) and 9 g of 1,3,5-trimethylbenzene were added, and the mixture was beaten for 1.5 h. The obtained raw material slurry was subjected to sand milling treatment to make the average particle size D(v, 0.5) of the raw material slurry less than 4 μm, and then spray dried to obtain catalyst microspheres.

[0146] The catalyst microspheres obtained by spray drying were calcined, washed to reduce sodium, and dried to obtain the catalytic cracking catalyst CAT-5 of the example.

[0147] According to the amount of the raw materials added, the titanium-phosphorus modified ZSM-5 molecular sieve Z-1 contained 3.5% titanium (calculated as an oxide) and 3.0% phosphorus (calculated as an oxide).

[0148] The raw material composition of the catalytic cracking catalyst CAT-5 was as follows: 15 wt% of kaolin (dry basis), 6 wt% of halloysite (dry basis), 25 wt% of pseudoboehmite (dry basis), 3 wt% of alumina from an aluminum sol, 35 wt% of GUSY-1 molecular sieve (dry basis), 1 wt% of the titanium-phosphorus modified micro-mesoporous ZSM-5 molecular sieve Z-1 (dry basis), 2 wt% of yttrium oxide, 6 wt% of silicon oxide from a silica sol, 6 wt% of titanium from the filter cake A (calculated as an oxide), and 1 wt% of magnesium from the filter cake A (calculated as an oxide). The catalyst gelation solid content was 32%.

[0149] Example 6

[0150] The example provides a catalytic cracking catalyst, and a preparation method thereof.

[0151] 1. Preparation of modified ZSM-5 molecular sieve:

[0152] (1) 1.402 kg of micro-mesoporous ZSM-5 molecular sieve (dry basis) was added into 4 L of deionized water, and stirred uniformly. Then, 125 g of titanium tetrachloride was added, and stirred for 0.5 h to form a slurry containing the molecular sieve (as a mixed solution). The slurry was dried at 120°C, and calcined at 500°C for 1 h. The pH value of the slurry containing the molecular sieve was 1.03.

[0153] (2) The calcined product of step (1) was mixed with 4 L of deionized water, and 73 g of phosphoric acid was added, and stirred uniformly. The mixture was dried at 120°C, and calcined at 500°C for 1 h to obtain a titanium-phosphorus modified micro-mesoporous ZSM-5 molecular sieve, which was denoted as Z-5.

[0154] The composition of the titanium-phosphorus modified micro-mesoporous ZSM-5 molecular sieve Z-5, calculated according to the amount of raw materials added, is: titanium (calculated as oxide) 3.5%, phosphorus (calculated as oxide) 3.0%, and the balance being ZSM-5 molecular sieve.

[0155] 2. Preparation of catalytic cracking catalyst CAT-6: the same as step 2 of Example 1, except that the modified ZSM-5 molecular sieve Z-1 therein is replaced by the modified ZSM-5 molecular sieve Z-5.

[0156] The raw material composition of the catalytic cracking catalyst CAT-6 is: kaolin 36.6 wt% (dry basis), pseudo-boehmite 20 wt% (dry basis), alumina from aluminum sol 6 wt%, USY molecular sieve 28 wt% (dry basis), titanium-phosphorus modified micro-mesoporous ZSM-5 molecular sieve Z-5 6 wt% (dry basis), yttrium oxide from yttrium nitrate 2 wt%, magnesium oxide from magnesium chloride 0.7 wt%, and rare earth oxide from rare earth chloride solution 0.7 wt%, and the catalyst gelation solid content is 38%. The catalyst gelation solid content is the solid content in the raw material slurry, that is, the ratio of the mass of the solid obtained after spray drying to the mass of the raw material slurry before spray drying.

[0157] Example 7

[0158] The present example provides a catalytic cracking catalyst, and a preparation method thereof, which comprises:

[0159] 1. Preparation of modified ZSM-5 molecular sieve:

[0160] (1) Under stirring, 712 g of titanium tetrachloride, 113.6 g of ferric nitrate, 21 g of n-hexane, and 110 g of carboxymethyl cellulose were added to 3.6 L of deionized water, stirred for 10 min, the pH value was adjusted to 6.51 with ammonia water, and then 1.102 kg of ordinary ZSM-5 molecular sieve (dry basis) was added, stirred for 1 h, a slurry containing the molecular sieve was formed, dried at 100°C, and calcined at 520°C for 1 h; wherein the pH value of the slurry containing the molecular sieve was 5.70;

[0161] (2) The calcined product of step (1), 110 g of carboxymethyl cellulose, and 3.6 L of deionized water were mixed, 139 g of diammonium hydrogen phosphate was then added, stirred uniformly, dried at 100°C, and calcined at 520°C for 1 h to obtain a titanium-iron-phosphorus modified ZSM-5 molecular sieve, which is denoted as Z-6.

[0162] 2. Preparation of catalytic cracking catalyst:

[0163] 0.45 kg of titanium-iron-phosphorus modified ZSM-5 molecular sieve Z-6 (dry basis) was added to 1.2 L of deionized water, stirred, and subjected to sand milling treatment to make the average particle size D(v, 0.5) of the molecular sieve Z-6 slurry less than 4 μm.

[0164] A slurry tank was charged with 0.906 kg of kaolin (dry basis), 1.944 kg of aluminum sol, 15 g of cerium oxide and 0.97 kg of deionized water, and then 0.24 kg of pseudo-boehmite (dry basis) was added, stirred for 1 h, and then 20 mL of nitric acid was added, stirred for 1 h, and then aged at 50°C for 1.2 h to obtain an intermediate system.

[0165] A slurry tank was charged with 0.72 kg of GUSY-1 molecular sieve (dry basis), 0.18 kg of REHY molecular sieve (dry basis), 0.45 kg (dry basis) of titanium-iron-phosphorus modified ZSM-5 molecular sieve Z-6 with an average particle size D(v, 0.5) of less than 4 μm, 54 g of yttrium oxide, 15 g of magnesium oxide, and 1.11 kg of deionized water, and then the slurry was mixed and slurried for 0.5 h, and then added to the first slurry tank, and then 150 g of carboxymethyl cellulose was added, and then slurried for 1.8 h, and then the obtained slurry was subjected to sand milling treatment to make the average particle size D(v, 0.5) of the slurry less than 4 μm, and then spray dried to obtain catalyst microspheres.

[0166] The catalyst microspheres obtained by spray drying were calcined, washed to reduce sodium, and dried to obtain the catalytic cracking catalyst CAT-7 of the present comparative example.

[0167] According to the amount of raw material added, the titanium-iron-phosphorus modified ZSM-5 molecular sieve Z-6 contained 20.0% titanium (as oxide), 1.5% iron (as oxide), and 5.0% phosphorus (as oxide).

[0168] The composition of the catalytic cracking catalyst CAT-7 was as follows: kaolin 30.2 wt% (dry basis), pseudo-boehmite 8 wt% (dry basis), aluminum oxide from aluminum sol 14 wt%, GUSY-1 molecular sieve 24 wt% (dry basis), REHY molecular sieve 6 wt% (dry basis), ZSM-5 molecular sieve Z-6 15 wt% (dry basis), yttrium oxide 1.8 wt%, cerium oxide 0.5 wt%, magnesium oxide 0.5 wt%, and the catalyst gel content was 36%.

[0169] Comparative Example 1

[0170] The present comparative example provides a catalytic cracking catalyst, and a preparation method thereof, which comprises:

[0171] 1. Preparation of modified ZSM-5 molecular sieve:

[0172] (1) 1.455 kg of micro-mesoporous ZSM-5 molecular sieve (dry basis) was added to 4 L of deionized water, stirred for 0.5 h to form a molecular sieve-containing slurry, dried at 120°C, and calcined at 500°C for 1 h; wherein the pH value of the molecular sieve-containing slurry was 2.51.

[0173] (2) The molecular sieve after step (1) is mixed with 4 L of deionized water, 73 g of phosphoric acid is added, stirred uniformly, dried at 120°C, and calcined at 500°C for 1 h to obtain the phosphorus-modified micro-mesoporous ZSM-5 molecular sieve DZ-1.

[0174] 2. Preparation of a catalytic cracking catalyst:

[0175] 1.098 kg of kaolin (dry basis), 0.833 kg of aluminum sol, 72.6 mL of rare earth chloride solution, and 1.52 kg of deionized water are added to a beater tank for beating, then 0.6 kg of pseudo-boehmite (dry basis) is added, stirred for 0.5 h, 91 mL of hydrochloric acid is added, stirred for 2 h, and then acidified at 70°C for 1.5 h.

[0176] 0.84 kg of USY molecular sieve (dry basis), 0.18 kg of phosphorus-modified micro-mesoporous ZSM-5 molecular sieve DZ-1 (dry basis), 203 g of yttrium nitrate, 106.7 g of magnesium chloride, and 1.52 kg of deionized water are mixed and beaten in the beater tank for 1.5 h, beaten for 2 h, homogenized, and spray dried to obtain catalyst microspheres.

[0177] The catalyst microspheres obtained by spray drying are calcined, washed to reduce sodium, and dried to obtain the catalytic cracking catalyst DCAT-1 of the present comparative example.

[0178] According to the amount of raw materials added, the phosphorus-modified ZSM-5 molecular sieve DZ-1 contains 3.0% phosphorus (calculated as an oxide), and the balance is ZSM-5 molecular sieve.

[0179] The raw material composition of the catalytic cracking catalyst DCAT-1 is: kaolin 36.6 wt% (dry basis), pseudo-boehmite 20 wt% (dry basis), aluminum oxide from aluminum sol 6 wt%, USY molecular sieve 28 wt% (dry basis), phosphorus-modified micro-mesoporous ZSM-5 molecular sieve DZ-1 6 wt% (dry basis), yttrium oxide from yttrium nitrate 2 wt%, magnesium oxide from magnesium chloride 0.7 wt%, and rare earth oxide from rare earth chloride solution 0.7 wt%, and the catalyst gel content is 38%.

[0180] Comparative Example 2

[0181] The present comparative example provides a modified ZSM-5 molecular sieve, which is prepared by the following method:

[0182] (1) 1.455 kg of ordinary ZSM-5 molecular sieve (dry basis) is added to 4 L of deionized water, stirred for 0.5 h to form a slurry containing the molecular sieve, dried at 120°C, and calcined at 500°C for 1 h; wherein the pH value of the slurry containing the molecular sieve is 2.53;

[0183] (2) The ZSM-5 molecular sieve after calcination in step (1) is mixed with 4 L of deionized water, 73 g of phosphoric acid is added, stirred uniformly, dried at 120°C, and calcined at 500°C for 1 h to obtain the phosphorus-modified ZSM-5 molecular sieve DZ-2.

[0184] The present comparative example provides a catalytic cracking catalyst, which is prepared according to the following method:

[0185] In a beater tank, 1.098 kg of kaolin (dry basis), 0.833 kg of aluminum sol, 72.6 mL of rare earth chloride solution, and 1.52 kg of deionized water are beaten, then 0.6 kg of pseudo-boehmite (dry basis) is added, stirred for 0.5 h, 91 mL of hydrochloric acid is added, stirred for 2 h, and then acidified at 70°C for 1.5 h to obtain an intermediate system.

[0186] The 0.84 kg of USY molecular sieve (dry basis), 0.18 kg of phosphorus-modified ZSM-5 molecular sieve DZ-2 (dry basis), 203 g of yttrium nitrate, 106.7 g of magnesium chloride, and 1.52 kg of deionized water are mixed and beaten for 1.5 h, then added to the intermediate system in the beater tank of the first step, beaten for 2 h, homogenized, and spray dried to obtain catalyst microspheres.

[0187] The catalyst microspheres obtained by spray drying are calcined, washed to reduce sodium, and dried to obtain the catalytic cracking catalyst DCAT-2 of the present comparative example.

[0188] According to the amount of raw materials added, the phosphorus-modified ZSM-5 molecular sieve DZ-2 contains 3.0% phosphorus (calculated as an oxide), and the balance is ZSM-5 molecular sieve.

[0189] The raw material composition of the catalytic cracking catalyst DCAT-2 is: kaolin 36.6 wt% (dry basis), pseudo-boehmite 20 wt% (dry basis), aluminum oxide from aluminum sol 6 wt%, USY molecular sieve 28 wt% (dry basis), modified ZSM-5 molecular sieve DZ-2 6 wt% (dry basis), yttrium oxide from yttrium nitrate 2 wt%, magnesium oxide from magnesium chloride 0.7 wt%, rare earth oxide from rare earth chloride solution 0.7 wt%, and catalyst gel content 38%.

[0190] Comparative Example 3

[0191] The present comparative example provides a catalytic cracking catalyst, which is prepared according to the following method:

[0192] The intermediate system was obtained by adding 1.2 kg of kaolin (dry basis), 0.972 kg of aluminum sol and 1.7 kg of deionized water into a beater tank for beating, then adding 0.54 kg of pseudo-boehmite (dry basis), 155.5 mL of rare earth chloride solution, stirring for 1.5 h, adding 91 mL of hydrochloric acid, stirring for 0.5 h, and acidifying at 50 °C for 1 h.

[0193] The intermediate system in the beater tank of the first step was added with 0.9 kg of GUSY-1 molecular sieve (dry basis), 60 g of common ZSM-5 molecular sieve (dry basis), 45 g of yttrium chloride (calculated as yttrium oxide), and 1.6 kg of deionized water, and then beating was carried out for 1 h, homogenization was carried out, and spray drying was carried out to obtain catalyst microspheres.

[0194] The catalyst microspheres obtained by spray drying were calcined, washed to reduce sodium, and dried to obtain the catalytic cracking catalyst DCAT-3 of the present comparative example.

[0195] The raw material composition of the catalytic cracking catalyst DCAT-3 was as follows: kaolin 40 wt% (dry basis), pseudo-boehmite 18 wt% (dry basis), aluminum oxide from aluminum sol 7 wt%, GUSY-1 molecular sieve 30 wt% (dry basis), common ZSM-5 molecular sieve 2 wt% (dry basis), yttrium oxide from yttrium chloride 1.5 wt%, and rare earth oxide from rare earth chloride solution 1.5 wt%, and the catalyst gelation solid content was 36%.

[0196] Comparative Example 4

[0197] The present comparative example provides a catalytic cracking catalyst, and the preparation method thereof is as follows:

[0198] The intermediate system was obtained by adding 1.2 kg of kaolin (dry basis), 0.972 kg of aluminum sol and 1.7 kg of deionized water into a beater tank for beating, then adding 0.54 kg of pseudo-boehmite (dry basis), 155.5 mL of rare earth chloride solution, stirring for 1.5 h, adding 91 mL of hydrochloric acid, stirring for 0.5 h, and acidifying at 50 °C for 1 h.

[0199] The intermediate system was obtained by adding 1.2 kg of kaolin (dry basis), 0.972 kg of aluminum sol and 1.7 kg of deionized water into a beater tank for beating, then adding 0.54 kg of pseudo-boehmite (dry basis), 155.5 mL of rare earth chloride solution, stirring for 1.5 h, adding 91 mL of hydrochloric acid, stirring for 0.5 h, and acidifying at 50 °C for 1 h.

[0200] The catalyst microspheres obtained by spray drying were calcined, washed to reduce sodium, and dried to obtain the catalytic cracking catalyst DCAT-3 of the present comparative example.

[0201] The raw material composition of the catalytic cracking catalyst DCAT-4 is: 30.2 wt% (dry basis) of kaolin, 8 wt% (dry basis) of pseudo-boehmite, 14 wt% of alumina from aluminum sol, 24 wt% (dry basis) of GUSY-1 molecular sieve, 6 wt% (dry basis) of REHY molecular sieve, 15 wt% (dry basis) of common ZSM-5 molecular sieve, 1.8 wt% of yttrium oxide, 0.5 wt% of cerium oxide, and 0.5 wt% of magnesium oxide, and the catalyst gel content is 36%.

[0202] Comparative Example 5

[0203] The present comparative example provides a catalytic cracking catalyst, and the preparation method thereof comprises the following steps:

[0204] 1. Preparation of modified ZSM-5 molecular sieve:

[0205] (1) 170.6 g of Fe(NO3)3·9H2O and 96 g of titanium tetrachloride were weighed and dissolved in a proper amount of distilled water to prepare a mixed impregnation solution of iron nitrate / titanium tetrachloride, which was slowly poured into 1.426 kg of common ZSM-5 molecular sieve (dry basis) while stirring to achieve equal-volume impregnation; after standing for 12 h, it was placed in a 120°C oven for drying for 6 h; and then it was calcined in a 540°C muffle furnace for 4 h to obtain the modified ZSM-5 molecular sieve DZ-3;

[0206] 2. Preparation of catalytic cracking catalyst:

[0207] 1.17 kg of kaolin (dry basis), 0.18 kg of diatomite (dry basis), 0.36 kg of pseudo-boehmite (dry basis), 207.4 mL of rare earth chloride solution, and 2.24 L of deionized water were added to a beater tank for beating, stirred for 1 h, 48.4 mL of hydrochloric acid was then added, stirred for 0.5 h, and then acidified at 55°C for 2 h to obtain an intermediate system.

[0208] 0.66 kg of GUSY-1 molecular sieve (dry basis), 0.3 kg of REHY molecular sieve (dry basis), 90 g of modified ZSM-5 molecular sieve DZ-3 (dry basis), and 1.67 kg of deionized water were mixed and beaten for 0.5 h, then added to the intermediate system in the beater tank of the first step, and then 180 g of aluminum sol was added, beaten for 1.5 h, homogenized, and spray dried to obtain catalyst microspheres.

[0209] The catalyst microspheres obtained by spray drying were calcined, washed to reduce sodium, and dried to obtain the catalytic cracking catalyst DCAT-5 of the present comparative example.

[0210] According to the raw material addition amount, the titanium-iron modified ZSM-5 molecular sieve contains 2.7% titanium (calculated as oxide) and 2.25% iron (calculated as oxide), and the balance is ZSM-5 molecular sieve.

[0211] The raw material composition of the catalytic cracking catalyst DCAT-5 is: kaolin 39 wt% (dry basis), diatomite 6 wt% (dry basis), pseudo-boehmite 12 wt% (dry basis), alumina from aluminum sol 6 wt%, GUSY-1 molecular sieve 22 wt% (dry basis), REHY molecular sieve 10 wt% (dry basis), modified ZSM-5 molecular sieve DZ-3 (dry basis) 3 wt%, rare earth oxide from rare earth chloride solution 2 wt%, and the catalyst gelation solid content is 35%.

[0212] Comparative Example 6

[0213] The present comparative example provides a catalytic cracking catalyst, and the preparation method thereof comprises the following steps:

[0214] 0.66 kg of kaolin (dry basis), 0.18 kg of halloysite (dry basis), 0.417 kg of aluminum sol and 2.94 kg of deionized water are added into a beater for beating, then 0.75 kg of pseudo-boehmite (dry basis) is added, stirred for 1 h, 101 mL of hydrochloric acid is added, stirred for 0.5 h, and then acidified at 55 °C for 2 h to obtain an intermediate system.

[0215] 1.05 kg of GUSY-1 molecular sieve (dry basis), 30 g of ordinary ZSM-5 molecular sieve (dry basis), 60 g of yttrium oxide and 1.81 kg of deionized water are mixed and beaten for 0.5 h, then added into the intermediate system of the first beater, 600 g of silica sol is added, beaten for 1.5 h, homogenized, and spray dried to obtain catalyst microspheres.

[0216] The catalyst microspheres obtained by spray drying are calcined, washed to reduce sodium, and dried to obtain the catalytic cracking catalyst DCAT-6 of the present comparative example.

[0217] The raw material composition of the catalytic cracking catalyst DCAT-6 is: kaolin 22 wt% (dry basis), halloysite 6 wt% (dry basis), pseudo-boehmite 25 wt% (dry basis), alumina from aluminum sol 3 wt%, GUSY-1 molecular sieve 35 wt% (dry basis), ordinary ZSM-5 molecular sieve (dry basis) 1 wt%, yttrium oxide 2 wt%, silicon oxide from silica sol 6 wt%, and the catalyst gelation solid content is 32%.

[0218] Comparative Example 7

[0219] The present comparative example provides a catalytic cracking catalyst, and the preparation method thereof comprises the following steps:

[0220] 1. Preparation of modified ZSM-5 molecular sieve:

[0221] (1) 1.402 kg of micro-intermediate pore ZSM-5 molecular sieve (dry basis) was added into 4 L of deionized water, stirred uniformly, then 73 g of phosphoric acid was added, stirred uniformly, dried at 120°C, and calcined at 500°C for 1 h;

[0222] (2) The calcined product of step (1) was mixed with 4 L of deionized water, 139 g of waste liquid containing titanium tetrachloride was added, stirred for 0.5 h to form a slurry containing molecular sieve, stirred uniformly, dried at 120°C, and calcined at 500°C for 1 h to obtain a phosphorus-titanium modified micro-intermediate pore ZSM-5 molecular sieve, which was denoted as DZ-4.

[0223] The phosphorus-titanium modified micro-intermediate pore ZSM-5 molecular sieve had a composition of 3.5% titanium (calculated as an oxide), 3.0% phosphorus (calculated as an oxide), and the balance being ZSM-5 molecular sieve.

[0224] 2. Preparation of catalytic cracking catalyst DCAT-7: the same as step 2 of Example 1, except that the modified molecular sieve Z-1 therein was replaced by modified molecular sieve DZ-4.

[0225] The titanium-phosphorus modified ZSM-5 molecular sieve DZ-4 contained 3.5% titanium (calculated as an oxide) and 3.0% phosphorus (calculated as an oxide), and the balance was ZSM-5 molecular sieve.

[0226] The raw material composition of the catalytic cracking catalyst DCAT-7 was: 36.6 wt% (dry basis) of kaolin, 20 wt% (dry basis) of pseudo-boehmite, 6 wt% of alumina from aluminum sol, 28 wt% (dry basis) of USY molecular sieve, 6 wt% (dry basis) of titanium-phosphorus modified micro-intermediate pore ZSM-5 molecular sieve DZ-4, 2 wt% of yttrium oxide from yttrium nitrate, 0.7 wt% of magnesium oxide from magnesium chloride, and 0.7 wt% of rare earth oxide from rare earth chloride solution, and the catalyst had a gel content of 38%.

[0227] The median particle size of the catalysts obtained in the above examples and comparative examples was 65-78 μm.

[0228] Test Example 1

[0229] (1) The test results of the hydrothermal stability of the modified ZSM-5 molecular sieves prepared in the above examples and comparative examples were provided.

[0230] The modified ZSM-5 molecular sieves prepared in Examples 1 to 4 and 6 to 7, and the modified ZSM-5 molecular sieves prepared in Comparative Examples 1, 2, 5 and 7 were respectively used as the sample to be tested, and the specific surface area of the sample to be tested was measured; then the specific surface area of each sample to be tested was measured after aging at 800°C under 100% steam for 17 h, and the specific surface area retention rate was calculated. The results are shown in Table 2.

[0231] Table 2 Test results of specific surface area retention rate of ZSM-5 molecular sieves of each example and comparative example

[0232]

[0233] The results of Table 2 show that, after aging at 800℃ for 17 hours under 100% steam, the ZSM-5 molecular sieve prepared by the method of the present application has a higher specific surface area retention rate than the comparative ZSM-5 molecular sieves DZ-1, DZ-2, DZ-3 and DZ-4 prepared in the comparative examples.

[0234] The difference between Example 1 and Comparative Example 1 is only whether titanium source is added. The specific surface area retention rate of the titanium-phosphorus modified ZSM-5 molecular sieve of Example 1 is 11.7% higher than that of the phosphorus modified ZSM-5 molecular sieve of Comparative Example 1.

[0235] The modification elements used in Example 4 and Comparative Example 5 are different. It can be seen from the comparison that the specific surface area retention rate of the titanium-iron-phosphorus modified ZSM-5 molecular sieve of Example 4 is 10.4% higher than that of the titanium-iron modified ZSM-5 molecular sieve of Comparative Example 5.

[0236] The difference between Comparative Example 7 and each example (especially Example 6) is the modification sequence of the phosphorus source and the titanium source. As can be seen from Table 2, compared with first modifying ZSM-5 molecular sieve with phosphorus and then modifying ZSM-5 molecular sieve with titanium, the reaction sequence of first modifying ZSM-5 molecular sieve with titanium and then modifying ZSM-5 molecular sieve with phosphorus used in the present application can significantly improve the specific surface area retention rate of the molecular sieve, and the improvement can reach more than 8 percentage points. The above results show that, by controlling the reaction sequence, the hydrothermal stability of ZSM-5 molecular sieve can be effectively improved.

[0237] The types of titanium sources used in Example 1 and Example 6 are different. As can be seen from Table 2, modifying the molecular sieve with pure titanium tetrachloride or waste liquid containing titanium tetrachloride as the titanium source can improve the specific surface area retention rate of the molecular sieve to a certain extent; among them, compared with pure titanium tetrachloride, the waste liquid containing titanium tetrachloride as the titanium source has a more obvious effect of improving the hydrothermal stability.

[0238] The above results show that, by using titanium and phosphorus as modification elements and controlling the reaction sequence, the preparation method of the present application can significantly improve the hydrothermal stability of the titanium-phosphorus modified ZSM-5 molecular sieve obtained thereby; on this basis, using iron, zirconium, zinc, magnesium, calcium, zirconium, lanthanum, cerium, yttrium as the second metal for modification can further improve the performance of ZSM-5 molecular sieve.

[0239] (2) The test example also provides the analysis results of the elemental composition of the modified ZSM-5 molecular sieves in the above examples and comparative examples. The contents of various elements in the samples of the above examples and comparative examples are tested by X-ray fluorescence analysis method, the weight contents of titanium, phosphorus, iron and zirconium are calculated based on oxides, and the weight content of chlorine is calculated based on Cl element, and the test results are summarized in Table 3.

[0240] Table 3 Analysis results of elemental contents of modified ZSM-5 molecular sieves in examples 1-4, examples 6-7 and comparative examples 1-2, comparative example 5, comparative example 7

[0241]

[0242] The main difference between comparative example 7 and each example (especially example 1) is that the ZSM-5 molecular sieve is first modified with phosphorus and then modified with titanium in comparative example 7, while the ZSM-5 molecular sieve is first modified with titanium and then modified with phosphorus in the examples. The results show that the Cl content in the modified ZSM-5 molecular sieves of each example is close to 0, while the Cl content in the modified ZSM-5 molecular sieve of comparative example 7 is more than 7%, indicating that the modified ZSM-5 molecular sieve prepared by the examples of the present application contains less impurities, and further indicating that the reaction sequence of the present application can effectively reduce the impurity content in the modified ZSM-5 molecular sieve and improve the quality of the molecular sieve. In the process of catalytic cracking reaction, if the chlorine content on the molecular sieve and catalyst is too high, it is easy to cause corrosion and salt deposition of the catalytic cracking device, which is not conducive to the long-term stable operation of the device.

[0243] The appearance color of the modified ZSM-5 molecular sieves (first titanium modification, then phosphorus modification) of each example is white, while the appearance color of the modified ZSM-5 molecular sieve (first phosphorus modification, then titanium modification) of comparative example 7 is gray. The results show that the template in the modified ZSM-5 molecular sieve of comparative example 7 is not easy to remove, and the template can block the molecular sieve channels, which has an adverse effect on the catalytic process; while the template in the modified ZSM-5 molecular sieve prepared by the present application is easy to remove by calcination process, thereby avoiding the situation that the template blocks the molecular sieve channels, which is beneficial to improve the selectivity of the molecular sieve in the catalytic reaction. The results of the pore volume determination also show that the pore volume of the modified ZSM-5 molecular sieve prepared by comparative example 7 is 0.25 mL / g, and the pore volume of the modified ZSM-5 molecular sieve prepared by example 1 is 0.31 mL / g, indicating that the modified ZSM-5 molecular sieve prepared by the present application has a relatively unobstructed pore structure.

[0244] The crystallinity of the modified ZSM-5 molecular sieves of Example 1, Example 2, Example 6, Comparative Example 1 and Comparative Example 7 was analyzed, and the results of the crystallinity of each molecular sieve were as follows: the crystallinity of the molecular sieve of Example 1 was 65%, the crystallinity of the molecular sieve of Example 2 was 66%, the crystallinity of the molecular sieve of Example 6 was 65%, the crystallinity of the molecular sieve of Comparative Example 1 was 60%, and the crystallinity of the molecular sieve of Comparative Example 7 was 63%. The main difference between Comparative Example 1 and Examples 1 and 2 was that Comparative Example 1 only used phosphorus-modified ZSM-5 molecular sieves and did not use titanium modification. During the modification of the molecular sieves, high-temperature calcination treatment was performed, which caused dealumination and structural damage to the molecular sieves during the calcination process, resulting in a decrease in the crystallinity of the molecular sieves measured by XRD. Therefore, the crystallinity of the molecular sieves in the modified product can reflect the stability of the molecular sieves. Compared with the modified ZSM-5 molecular sieves prepared in Comparative Example 1, the crystallinity of the ZSM-5 molecular sieves in the modified ZSM-5 molecular sieves of Examples 1, 2 and 6 increased by more than 5 percentage points, indicating that the titanium-phosphorus synergistic modification made the modified ZSM-5 molecular sieves prepared in the present application more stable than the modified ZSM-5 molecular sieves of Comparative Example 1. Compared with the modified ZSM-5 molecular sieves of Comparative Example 7, the crystallinity of the ZSM-5 molecular sieves in the modified ZSM-5 molecular sieves of Example 1 increased by 2 percentage points, while the crystallinity of the ZSM-5 molecular sieves in the modified ZSM-5 molecular sieves of Comparative Example 7 was lower, at 63%, which also indicates that the modified ZSM-5 molecular sieves prepared in the present application are more stable than the modified ZSM-5 molecular sieves of Comparative Example 7. The above results show that the stability of the ZSM-5 molecular sieves can be effectively improved by titanium-phosphorus synergistic modification (further modification with modification metals such as zirconium) and control of the modification sequence.

[0245] Test Example 2

[0246] This example was used to evaluate the performance of the catalytic cracking catalysts of Examples 1-3 and Comparative Examples 1-4.

[0247] The catalytic cracking catalysts CAT-1, CAT-2 and CAT-3 prepared in Examples 1, 2 and 3 and the comparative catalytic cracking catalysts DCAT-1, DCAT-2, DCAT-3 and DCAT-4 prepared in Comparative Examples 1, 2, 3 and 4 were used as the samples to be tested. The samples to be tested were aged at 800°C and 100% steam for 17 hours, and then the catalytic cracking reaction performance of each sample was evaluated on a heavy oil micro-reaction evaluation device (ACE) using the feedstock oil processed in a 3 million ton / year catalytic cracking device of Lanzhou Petrochemical Company.

[0248] The results of the reaction selectivity evaluation of the catalytic cracking catalysts of Examples 1-3 and Comparative Examples 1-4 are shown in Table 4.

[0249] In Table 4, total liquid yield = liquefied gas yield + gasoline yield + diesel yield; coke factor = (100 - conversion rate) x coke yield / conversion rate.

[0250] Table 4

[0251]

[0252] The results in Table 4 show that, compared with the comparative catalytic cracking catalyst DCAT-2, the reaction conversion rate of the catalyst CAT-1 prepared in Example 1 is increased by 1.61 percent points, the total liquid yield (liquefied gas + gasoline + diesel) is increased by 1.75 percent points, the coke yield is reduced by 0.43 percent points, the coke factor is reduced, and the low-carbon olefin (ethylene + propylene + butene) yield is increased by 2.80 percent points; compared with the comparative catalyst DCAT-4, the reaction conversion rate of the catalyst CAT-3 prepared in Example 3 is increased by 2.24 percent points, the total liquid yield (liquefied gas + gasoline + diesel) is increased by 1.97 percent points, the coke yield is reduced by 0.75 percent points, the coke factor is reduced, the low-carbon olefin (ethylene + propylene + butene) yield is increased by 5.77 percent points, and the catalytic cracking catalysts of Example 1 and Example 3 show excellent heavy oil conversion, reduced coking, and prolific low-carbon olefin production.

[0253] The above results show that, compared with the comparative catalytic cracking catalysts DCAT-1, DCAT-2, DCAT-3, and DCAT-4 prepared in Comparative Examples 1, 2, 3, and 4, the reaction conversion rate of the catalytic cracking catalysts CAT-1, CAT-2, and CAT-3 of the present application is increased, the heavy oil yield is reduced, the coke factor is reduced, and the low-carbon olefin (ethylene + propylene + butene) yield and selectivity are increased. This shows that, when the catalytic cracking catalyst provided by the present application is used, the efficient conversion of heavy oil is promoted, the coking tendency is reduced, low-carbon olefins are prolific, and the selectivity of the catalytic cracking reaction is improved.

[0254] Test Example 3

[0255] This test example is used to evaluate the performance of the catalytic cracking catalysts of Example 4-5 and Comparative Examples 5-6.

[0256] The catalytic cracking catalysts CAT-4 and CAT-5 prepared in Examples 4 and 5 and the comparative catalytic cracking catalysts DCAT-5 and DCAT-6 prepared in Comparative Examples 5 and 6 are used as the samples to be tested, and the samples to be tested are respectively subjected to aging treatment at 800℃ and 100% steam for 17h, and then the catalytic cracking reaction performance evaluation is carried out on a heavy oil micro-reaction evaluation device (ACE) using the feedstock oil processed in a 3 million tons / year catalytic cracking device of Lanzhou Petrochemical Company as the raw material oil.

[0257] The results of the reaction selectivity evaluation of the catalytic cracking catalysts of Examples 4-5 and Comparative Examples 5-6 are shown in Table 5. In the table, total liquid yield = LPG yield + gasoline yield + diesel yield; coke factor = (100 - conversion rate) x coke yield / conversion rate.

[0258] Table 5

[0259]

[0260] The results in Table 5 show that, compared with the comparative catalytic cracking catalyst DCAT-5, the catalytic cracking catalyst CAT-4 prepared in Example 4 has an increased reaction conversion rate by 1.55%, an increased total liquid yield (LPG + gasoline + diesel) by 1.50%, a decreased coke yield by 0.20%, a decreased coke factor, an increased low-carbon olefin (ethylene + propylene + butene) yield by 2.26%, showing excellent heavy oil conversion, reduced coking and prolific production of low-carbon olefins.

[0261] The above results show that, compared with the comparative catalytic cracking catalysts DCAT-5 and DCAT-6 prepared in Comparative Examples 5 and 6, the catalytic cracking catalysts CAT-4 and CAT-5 of the present application have an increased reaction conversion rate, a decreased heavy oil yield, a decreased coke factor, an increased low-carbon olefin (ethylene + propylene + butene) yield and selectivity. This shows that, compared with the prior art catalysts with or without titanium, the use of the catalysts provided by the present application promotes efficient conversion of heavy oil, reduces the heavy oil yield, reduces the coking tendency, produces more low-carbon olefins and improves the selectivity of the catalytic cracking reaction.

[0262] Test Example 4

[0263] This test example is used to evaluate the performance of the catalytic cracking catalysts of Examples 3, 6-7.

[0264] The catalytic cracking catalysts CAT-3, CAT-6 and CAT-7 prepared in Examples 3, 6 and 7 are used as the samples to be tested, and the samples to be tested are respectively subjected to aging treatment at 800°C and 100% steam for 17h, and then the catalytic cracking reaction performance is evaluated on a heavy oil micro-reaction evaluation device (ACE) using the feedstock oil processed in a 3 million tons / year catalytic cracking device of Lanzhou Petrochemical Company as the feedstock oil.

[0265] The results of the reaction selectivity evaluation of the catalytic cracking catalysts of Examples 3, 6-7 are shown in Table 6. In the table, total liquid yield = LPG yield + gasoline yield + diesel yield; coke factor = (100 - conversion rate) x coke yield / conversion rate.

[0266] Table 6

[0267]

[0268] The results in Table 6 show that the catalytic cracking catalysts prepared in Examples 3, 6 and 7 all have high conversion rate and total liquid yield. Further, compared with the catalytic cracking catalyst CAT-7, the catalyst CAT-3 prepared in Example 3 has a conversion rate increased by 0.58 percent points, a total liquid yield (liquefied gas + gasoline + diesel) increased by 0.56 percent points, a coke yield decreased by 0.16 percent points, a coke factor decreased, and a low-carbon olefin (ethylene + propylene + butene) yield increased by 1.93 percent points; compared with the catalytic cracking catalyst CAT-6, the catalyst CAT-1 prepared in Example 1 shows the same performance characteristics. Compared with the catalysts prepared in Comparative Examples 1-6, the catalysts CAT-3, CAT-6 and CAT-7 have reduced heavy oil, coke and coke factor, indicating that the catalysts prepared by using pure titanium tetrachloride, a combination of titanium tetrachloride and n-hexane, and waste liquid containing titanium tetrachloride can improve the catalytic reaction selectivity of the catalysts.

Claims

1. A catalytic cracking catalyst, wherein, Based on the weight of the raw materials for the catalytic cracking catalyst as 100%, the raw materials for the catalytic cracking catalyst include: 0.5%-20% modified ZSM-5 molecular sieve, 15%-50% Y-type molecular sieve, 10%-55% clay, 5%-30% aluminum source, 3%-15% binder, and 0.2%-5% modified metal element from the second modifier; wherein, the weight of the modified ZSM-5 molecular sieve, Y-type molecular sieve, clay, and aluminum source is on a dry basis, and the weight of the binder and modified metal element is on an oxide basis; The method for preparing the modified ZSM-5 molecular sieve includes: mixing raw material ZSM-5 with a titanium source of a first modifier to form a mixture, and performing a first calcination; mixing the product of the first calcination with a phosphorus source, and performing a second calcination to obtain the modified ZSM-5 molecular sieve; the first modifier includes a titanium source and a phosphorus source.

2. The catalytic cracking catalyst according to claim 1, wherein, The method for preparing the modified ZSM-5 molecular sieve includes: fully impregnating the raw material ZSM-5 molecular sieve with an impregnation solution containing a titanium source and a first modifier, drying it, and performing a first calcination; mixing the product of the first calcination with a phosphorus source and performing a second calcination to obtain the modified ZSM-5 molecular sieve; the first modifier includes a titanium source and a phosphorus source.

3. The catalytic cracking catalyst according to claim 1 or 2, wherein, Based on the weight of 100% of the modified ZSM-5 molecular sieve, the modified ZSM-5 molecular sieve includes 0.2%-25% titanium and 0.2%-6% phosphorus; wherein the weight of the titanium and phosphorus is calculated as oxides.

4. The catalytic cracking catalyst according to claim 3, wherein, The weight content of titanium from the first modifier in the modified ZSM-5 molecular sieve, based on titanium oxide, is 0.5%-15%. And / or, based on phosphorus oxides, the weight content of phosphorus from the first modifier in the modified ZSM-5 molecular sieve is 0.5%-6%.

5. The catalytic cracking catalyst according to claim 3, wherein, The ZSM-5 molecular sieve further includes modified metal elements, and the first modifier further includes a modified metal source; the modified metal elements include one or more combinations of iron, zinc, magnesium, calcium, zirconium, and rare earth elements; Based on the oxides of the modified metal elements, the mass percentage of the modified metal elements from the first modifier in the modified ZSM-5 molecular sieve is 0-5% and not 0.

6. The catalytic cracking catalyst according to claim 1 or 2, wherein, The temperature of the first roasting is 450-650℃, and the roasting time is 1-4h; The second roasting temperature is 450-650℃, and the second roasting time is 1-4h.

7. The catalytic cracking catalyst according to claim 1, wherein, The pH value of the mixture is 0.5-8.

8. The catalytic cracking catalyst according to claim 7, wherein, The pH value of the mixture is 0.5-3.

9. The catalytic cracking catalyst according to claim 2, wherein, The pH value of the impregnation solution is 0.5-8.

10. The catalytic cracking catalyst according to claim 9, wherein, The pH value of the impregnation solution is 0.5-3.

11. The catalytic cracking catalyst according to claim 1, wherein, The aluminum source includes one or more of the following: boehmite, amorphous alumina, boehmite, aluminum nitrate, and aluminum chloride.

12. The catalytic cracking catalyst according to claim 1, wherein, The clay includes one or more of the following: kaolin, montmorillonite, diatomite, and sepiolite.

13. The catalytic cracking catalyst according to claim 1, wherein, The clay includes one or more of halloysite and bentonite.

14. The catalytic cracking catalyst according to claim 1, wherein, The modified metal element includes one or more of the following: iron, zinc, magnesium, calcium, zirconium, and rare earth elements.

15. The catalytic cracking catalyst according to claim 1, wherein, The second modifier also includes a titanium source, wherein the titanium from the second modifier, calculated as titanium oxide, has a weight content of 0-10% and not 0% in the feedstock of the catalytic cracking catalyst.

16. The catalytic cracking catalyst according to any one of claims 1, 2, or 15, wherein, The titanium source in the first modifier and the second modifier includes titanium tetrachloride.

17. The catalytic cracking catalyst according to claim 16, wherein, The titanium source in the first and second modifiers includes titanium tetrachloride and hexane in a weight ratio of (4-34):

1.

18. The catalytic cracking catalyst according to claim 16, wherein, The titanium source in the first modifier and the second modifier includes waste liquid containing titanium tetrachloride; based on the total weight of the waste liquid containing titanium tetrachloride as 100%, the waste liquid containing titanium tetrachloride includes: 80%-95% titanium tetrachloride, 2%-5% alkoxy titanium complex, and the balance is hydrocarbons, including hexane.

19. The catalytic cracking catalyst according to claim 1, wherein, The raw materials for the catalytic cracking catalyst also include an inorganic oxide support, which includes one or more of the following: silica, alumina containing Brønsted acid centers, and aluminosilicate containing Brønsted acid centers.

20. The catalytic cracking catalyst according to claim 19, wherein, The inorganic oxide support, by weight based on oxides, is 0-30% of the feedstock weight of the catalytic cracking catalyst and is not zero.

21. The catalytic cracking catalyst according to claim 1, wherein, The raw material for the catalytic cracking catalyst, based on 100% by weight, includes 1%-18% of modified ZSM-5 molecular sieve on a dry basis. And / or, based on 100% by weight of the catalytic cracking catalyst, the feedstock of the catalytic cracking catalyst includes 20%-45% Y-type molecular sieve on a dry basis.

22. A method for preparing the catalytic cracking catalyst according to any one of claims 1-21, the method comprising: Modified ZSM-5 molecular sieve, Y-type molecular sieve, clay, aluminum source, binder and second modifier are mixed and pulped to form raw material slurry; The raw material slurry is spray-dried and calcined to obtain the catalytic cracking catalyst; The second modifier includes a modified metal source.

23. The preparation method according to claim 22, wherein, The preparation method further includes an acidification process involving at least a portion of the binder, clay, and second modifier from the modified metal source with an aluminum source.

24. The preparation method according to claim 23, wherein, The acidification treatment temperature is 40-90℃, and the acidification treatment time is 0.5-3h.

25. The preparation method according to claim 22, wherein, The raw material slurry also includes a pore structure improver, which includes one or more of 1,3,5-trimethylbenzene, 1,3,5-triisopropylbenzene, methylcellulose, carboxymethylcellulose, polyvinyl alcohol, and polyethylene glycol.

26. The preparation method according to claim 25, wherein, The weight of the pore structure improver is 0.1%-10% of the weight of the feedstock of the catalytic cracking catalyst.

27. The use of the catalytic cracking catalyst according to any one of claims 1-21 in the catalytic cracking process.

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