A catalytic cracking catalyst for producing propylene in large amount and its preparation method and application

Abstract

The application provides a propylene-rich catalytic cracking catalyst and a preparation method and application thereof, wherein the preparation method comprises the following steps: first, using ammonium sulfate as an exchanger, and adding a precipitant before the ammonium sulfate is exchanged, the precipitant preferentially generates a precipitated precursor of rare earth oxide with rare earth ions, so that a rare earth modified Y type molecular sieve with low sulfate content, high crystallinity and good stability is prepared; water, the rare earth modified Y type molecular sieve, ZSM-5 molecular sieve, clay and a binder are fully mixed, and then homogenization, spray drying and third calcination are performed to prepare a Na-containing catalyst; water and the Na-containing catalyst particles are mixed and beaten to pulp, and then a phosphorus-containing substance is added to modify the Na-containing catalyst, and then the modified Na-containing catalyst is filtered, washed with water and dried to prepare a finished catalyst. The finished catalyst uses the rare earth modified Y type molecular sieve with the above characteristics as an active component, so that the finished catalyst has the advantages of high propylene yield, strong heavy oil conversion capacity and high liquid yield.

Description

TECHNICAL FIELD

[0001] The present application relates to a catalytic cracking catalyst for producing propylene and a preparation method and application thereof, and belongs to the technical field of refining. BACKGROUND

[0002] The catalytic cracking device is still one of the most important devices in the refining process, and about 70% of gasoline and 35% of propylene come from the catalytic cracking device. However, with the overcapacity of fuel oil, the relative shortage of chemical raw materials and the accelerated pace of gasoline quality upgrading, new and severe challenges are posed to catalytic cracking. At the same time, the demand for chemical raw materials such as propylene and other low-carbon olefins is strong, and the gap between the market demand for propylene and the production capacity of traditional sources of propylene is becoming larger and larger, and is in a state of expansion.

[0003] In summary, how to improve the propylene yield on the basis of efficient conversion of heavy oil is a new task and challenge for catalytic cracking in the current refining transformation and upgrading, and has become an important research topic for petroleum refiners. The key material for catalytic cracking to produce more propylene is ZSM-5 molecular sieve, but ZSM-5 molecular sieve has small pore size and is limited by diffusion, so heavy oil macromolecules cannot enter its pore channel for cracking, and it only has strong cracking activity for small molecules in the gasoline fraction to increase propylene production. Catalytic cracking is a typical gas-solid heterogeneous reaction, which is a parallel sequential reaction, and its reaction is limited by diffusion. Therefore, to increase propylene production, on the one hand, heavy oil macromolecules are converted into gasoline intermediate fraction molecules by large-pore Y-type molecular sieve and the like, and on the other hand, gasoline molecules are cracked and converted into propylene by medium-pore ZSM-5 molecular sieve.

[0004] For this purpose, part of the existing technology mainly uses P-modified ZSM-5 to improve its hydrothermal stability and activity stability, so as to achieve the purpose of increasing propylene yield; part of the existing technology uses the method of combining USY and ZSM-5 to achieve relay cracking to increase propylene production; part of the existing technology uses Y zeolite, ZSM-5 zeolite and beta zeolite to combine to produce more propylene; and part of the existing technology uses methods such as adding medium-large pore matrix material, ZSM-5 protective coating to increase propylene production.

[0005] Although the prior art as shown above can improve the propylene yield, and more and more attention is paid to the gradient cracking of materials with different pore sizes, but since the existing Y-type molecular sieve is mostly USY molecular sieve, the cracking activity is insufficient, so as to not provide more gasoline intermediate fraction molecules for ZSM-5 cracking to be rich in propylene. Therefore, it is necessary to make technical innovation to improve the cracking activity and stability of Y-type molecular sieve. Y-type molecular sieve is still the main active component of FCC catalyst due to its unique three-dimensional pore structure, suitable acidity and good stability, and its performance determines the activity, stability, heavy oil conversion performance and product selectivity of the catalyst, and has become one of the research hotspots to improve the performance of heavy oil catalyst. Catalytic cracking is a typical acid-catalyzed gas-solid heterogeneous reaction, which follows the mechanism of carbenium ion, and NaY molecular sieve itself does not have acidity, and usually needs to be exchanged and modified to remove its Na ion, and adjust its acidity and pore structure. Since the acid H + The acidity is too strong, which is easy to damage the framework structure of Y-type molecular sieve, causing the decrease of crystallinity and selectivity, and the REY-type molecular sieve is easy to coke and deactivate in the process of catalytic cracking reaction due to its strong acidity and acid density, therefore, the commonly used modification method is to exchange with ammonium salt or / and rare earth, and to prepare modified REHY or REUSY-type molecular sieve with different acidity and pore structure by heat or hydrothermal calcination. At present, the preparation method of REHY or REUSY-type molecular sieve is roughly divided into two types: one is to exchange a small amount of rare earth ions and / or ammonium ions with NaY molecular sieve, and to prepare REUSY molecular sieve by calcination and rare earth ion and / or ammonium ion or dealuminization treatment; the other is to prepare REUSY by exchanging rare earth after preparing USY from NaY molecular sieve.

[0006] Ammonium chloride is easy to decompose at high temperature, and crystallize at low temperature, so it is easy to block the catalyst flue and bag dust collector, resulting in continuous production; and ammonium nitrate can explode under high temperature, high pressure, and the presence of oxidizable substances (reducing agent) and electric spark, and is a key raw material for making explosives, and is high in price, therefore, it is not used; ammonium sulfate is stable in nature and low in price, and is commonly used for industrial molecular sieve exchange modification, but it is easy to form rare earth sulfate precipitate with rare earth, on the one hand, leading to the migration of rare earth ions into the cage of molecular sieve, and on the other hand, causing the excessive standard of sulfate, damaging the framework structure of molecular sieve, and the sulfate will be converted into sulfide in the refining process after being made into catalyst, corroding the equipment.

[0007] In the prior art, the method of precipitating rare earth is often used to improve the utilization rate of rare earth and generate independent phase of rare earth to improve the anti-V pollution performance of the molecular sieve; the exchange of rare earth and ammonium salt is performed simultaneously, which leads to low exchange efficiency due to the existence of competitive exchange; the exchange of ammonium salt is performed before the exchange of rare earth, and the use of ammonium chloride and ammonium nitrate will cause high cost, equipment corrosion and other problems, while the use of low-cost recyclable ammonium sulfate needs a large amount of water washing to remove sulfate to increase water consumption. The pre-exchange can reduce the sodium oxide and sulfate of the modified molecular sieve, but it has the problems of long process, high water consumption and high cost. The REY molecular sieve prepared without ammonium salt has the problem of high coke.

[0008] In summary, the prior art inevitably causes the problems of high sulfate, low crystallinity, equipment corrosion, long production process and high cost. Therefore, it is urgent to develop a new method for preparing a low-sulfate rare earth ion molecular sieve to improve the activity, stability and heavy oil conversion capacity of the catalytic cracking catalyst and avoid the conversion of sulfate to sulfide in the application process to cause the corrosion of equipment. SUMMARY

[0009] In order to solve the above-mentioned defects and deficiencies, one object of the present application is to provide a catalytic cracking catalyst for producing more propylene.

[0010] Another object of the present application is also to provide a preparation method of the above-mentioned catalytic cracking catalyst for producing more propylene.

[0011] Still another object of the present application is also to provide the application of the above-mentioned catalytic cracking catalyst for producing more propylene in the catalytic cracking of heavy oil to produce propylene.

[0012] In order to achieve the above objects, in one aspect, the present application provides a preparation method of a catalytic cracking catalyst for producing more propylene, wherein the preparation method comprises:

[0013] (1) preparation of a low-sulfate rare earth modified Y-type molecular sieve:

[0014] Step one: performing rare earth ion exchange on a Na-type molecular sieve to obtain a rare earth ion slurry / rare earth ion exchange slurry;

[0015] Step two: adding a first precipitant to make the rare earth ions in the rare earth ion exchange slurry be first precipitated to obtain a first precipitation slurry;

[0016] Step three: the first precipitation slurry is sequentially subjected to filtration, first ammonium sulfate exchange, first water washing and first calcination to obtain a one-exchange-one-calcination molecular sieve dry powder;

[0017] Step four: the one-inter one-calcined molecular sieve dry powder is slurried with water, a second precipitant is added to precipitate the rare earth ions in the one-inter one-calcined molecular sieve dry powder, and then a second ammonium sulfate exchange, a second water washing, and a second calcination are sequentially performed to obtain a low-sulfate rare earth modified Y-type molecular sieve;

[0018] (2) Catalyst shaping:

[0019] The water, the low-sulfate rare earth modified Y-type molecular sieve, the ZSM-5 molecular sieve, the clay, and the binder are fully mixed, and then homogenized, spray-dried, and thirdly calcined to obtain a Na-containing catalyst;

[0020] (3) Phosphorus-containing substance sodium reduction modification:

[0021] The water and the Na-containing catalyst particles are mixed and slurried, and then a phosphorus-containing substance is added to modify the Na-containing catalyst, and then the modified Na-containing catalyst is filtered, washed with water, and dried to obtain a high-yield propylene catalytic cracking catalyst.

[0022] As a specific embodiment of the preparation method described above, in step one, the rare earth ion exchange conditions include a temperature of 25-180°C, preferably 50-80°C; a pH of 2.8-6.5, preferably 3.5-4.5; and a time of 0.3-3.5h, preferably 0.5-1.5h.

[0023] As a specific embodiment of the preparation method described above, the rare earth ion exchange process includes mixing the Na-type molecular sieve and water, and then adding a soluble rare earth salt to perform the rare earth ion exchange.

[0024] As a specific embodiment of the preparation method described above, the weight ratio of the Na-type molecular sieve to water is 1:1.5-30, for example, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:10, 1:20, 1:30, and any value within the range defined by any two values, and preferably 1:2-5.

[0025] As a specific embodiment of the preparation method described above, the content of the soluble rare earth salt in terms of oxide in the Na-type molecular sieve in terms of dry basis is 1-20wt%, for example, 1wt%, 4wt%, 6wt%, 8wt%, 10wt%, 12wt%, 14wt%, 16wt%, 20wt%, and any value within the range defined by any two values, and preferably 6-16wt%. The use of the preferred conditions is more conducive to reducing the sulfate content in the low-sulfate rare earth modified Y-type molecular sieve, thereby eliminating the influence of sulfate on the performance of the low-sulfate rare earth modified Y-type molecular sieve and improving the crystallinity and catalytic performance of the low-sulfate rare earth modified Y-type molecular sieve.

[0026] In the present application, the rare earth ions in the soluble rare earth salt are completely attached to the surface and internal channels of the Na-type molecular sieve during the rare earth ion exchange process. Therefore, the weight ratio of the Na-type molecular sieve on a dry basis to the soluble rare earth salt on an oxide basis is 100:1-20, preferably 100:6-16.

[0027] In the present application, the solubility means easy to dissolve in water or easy to dissolve in water with the aid of an auxiliary agent, unless otherwise specified.

[0028] As a specific embodiment of the above preparation method of the present application, the soluble rare earth salt is selected from one or a combination of several of soluble nitrates, chlorides and the like of lanthanum, cerium, yttrium and other rare earth metals.

[0029] As a specific embodiment of the above preparation method of the present application, the Na-type molecular sieve has a silicon-aluminum ratio of 2-100, preferably 2-50.

[0030] As a specific embodiment of the above preparation method of the present application, the Na-type molecular sieve is selected from at least one of NaY molecular sieve, NaHY molecular sieve, NaUSY molecular sieve, NaREHY molecular sieve, NaREUSY molecular sieve, Naβ molecular sieve, NaHβ molecular sieve, NaREHβ molecular sieve, NaX molecular sieve, NaREX molecular sieve and NaHX molecular sieve, and preferably selected from NaY molecular sieve and / or NaHY molecular sieve.

[0031] As a specific embodiment of the above preparation method of the present application, in step two, the amount of the first precipitant is determined according to the amount of the rare earth ions added, and the molar ratio in the precipitation reaction is sufficient, for example, the amount of the first precipitant is sufficient for the molar ratio of the rare earth ions with a content of 1-4 wt% in the Na-type molecular sieve to be precipitated, and preferably for the molar ratio of the rare earth ions with a content of 1.5-2.5 wt% in the Na-type molecular sieve to be precipitated. The use of the preferred conditions is more conducive to reducing the sulfate content of the low-sulfate rare earth modified Y-type molecular sieve, and further improving the crystallinity and catalytic performance of the low-sulfate rare earth modified Y-type molecular sieve.

[0032] As a specific embodiment of the above preparation method of the present application, the first precipitant is a precipitant that can precipitate rare earth oxides, for example, at least one selected from ammonium oxalate, ammonium carbonate, ammonium bicarbonate, ammonia, urea and ammonium acetate, and preferably at least one selected from ammonium oxalate, ammonium carbonate, ammonium bicarbonate and ammonia.

[0033] As an embodiment of the above preparation method of the present application, the conditions of the first precipitation include: temperature of 25-180°C, preferably 50-80°C; time of 0.1-5h, preferably 0.1-2h.

[0034] As an embodiment of the above preparation method of the present application, in step three, the first ammonium sulfate exchange process includes: exchanging the filtered product with the first ammonium sulfate aqueous solution.

[0035] As an embodiment of the above preparation method of the present application, the weight ratio of the first ammonium sulfate aqueous solution to the Na-type molecular sieve, in terms of ammonium sulfate, is 5-50:100, for example, 5:100, 10:100, 15:100, 20:100, 25:100, 30:100, 40:100, 50:100, and any value in the range between any two of the values, preferably 10-25:100.

[0036] As an embodiment of the above preparation method of the present application, the concentration of ammonium sulfate in the first ammonium sulfate aqueous solution is 20-400g / L, for example, 20g / L, 50g / L, 80g / L, 120g / L, 150g / L, 200g / L, 250g / L, 300g / L, 400g / L, and any value in the range between any two of the values, preferably 120-250g / L.

[0037] As an embodiment of the above preparation method of the present application, the conditions of the first ammonium sulfate exchange include: temperature of 15-150°C, preferably 50-80°C; time of 0.1-5h, preferably 0.5-2h.

[0038] As an embodiment of the above preparation method of the present application, the first ammonium sulfate exchange is tank exchange, belt exchange, or both tank exchange and belt exchange; preferably tank exchange.

[0039] As an embodiment of the above preparation method of the present application, in step three, the amount of water used in the first water washing is 1-8 times the weight of the Na-type molecular sieve, for example, 1 times, 2 times, 3 times, 4 times, 5 times, 8 times, and any value in the range between any two of the values, preferably 2-5 times.

[0040] As an embodiment of the above preparation method of the present application, the conditions of the first calcination include: 100% steam atmosphere; temperature of 400-700°C, preferably 500-650°C; time of 0.1-5h, preferably 0.5-3h.

[0041] As a specific embodiment of the above preparation method of the present application, in step four, the amount of the second precipitant is determined according to the amount of the rare earth ions added, and the molar ratio in the precipitation reaction is met, for example, the amount of the second precipitant meets the molar ratio of the second precipitation of the rare earth ions in the amount of 0.5-3wt% in the dry powder of the first-interchange-first-calcination molecular sieve, preferably meets the molar ratio of the second precipitation of the rare earth ions in the amount of 1-2wt% in the dry powder of the first-interchange-first-calcination molecular sieve. Using the preferred conditions, it is more conducive to reduce the sulfate content of the low-sulfate rare earth modified Y-type molecular sieve, and further improve the crystallinity and catalytic performance of the low-sulfate rare earth modified Y-type molecular sieve.

[0042] As a specific embodiment of the above preparation method of the present application, the second precipitant is a precipitant that can precipitate rare earth oxides, for example, it can be selected from at least one of ammonium oxalate, ammonium carbonate, ammonium bicarbonate, ammonia, urea, and ammonium acetate, and preferably at least one of ammonium oxalate, ammonium carbonate, ammonium bicarbonate, and ammonia.

[0043] As a specific embodiment of the above preparation method of the present application, the conditions of the second precipitation include: the temperature is 15-40℃, preferably 20-30℃; the time is 0.1-5h, preferably 0.1-2h.

[0044] As a specific embodiment of the above preparation method of the present application, the weight ratio of the dry powder of the first-interchange-first-calcination molecular sieve to water is 1:1.5-30, for example, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:10, 1:20, 1:30, and any value in the range composed of any two numerical values, preferably 1:2-5.

[0045] As a specific embodiment of the above preparation method of the present application, in step four, the process of the second ammonium sulfate exchange includes: exchanging the second precipitation product and the second ammonium sulfate aqueous solution.

[0046] As a specific embodiment of the above preparation method of the present application, the weight ratio of the second ammonium sulfate aqueous solution to the dry powder of the first-interchange-first-calcination molecular sieve, calculated based on ammonium sulfate, is 5-50:100, for example, 5:100, 10:100, 15:100, 20:100, 25:100, 30:100, 40:100, 50:100, and any value in the range composed of any two numerical values, preferably 10-25:100.

[0047] As a specific embodiment of the above preparation method of the present application, the concentration of ammonium sulfate in the second ammonium sulfate aqueous solution is 20-400 g / L, for example, 20 g / L, 50 g / L, 80 g / L, 120 g / L, 150 g / L, 200 g / L, 250 g / L, 300 g / L, 400 g / L, preferably 120-250 g / L.

[0048] As a specific embodiment of the above preparation method of the present application, the second ammonium sulfate exchange is carried out at a temperature of 20-85°C, preferably 50-80°C, for a time of 0.1-5 h, preferably 0.1-2 h.

[0049] As a specific embodiment of the above preparation method of the present application, the second ammonium sulfate exchange is carried out in a tank, on a belt, or simultaneously in a tank and on a belt; preferably in a tank.

[0050] As a specific embodiment of the above preparation method of the present application, the amount of water used in the second washing is 1-8 times the weight of the first ion-exchanged and calcined molecular sieve dry powder, for example, 1 times, 2 times, 3 times, 4 times, 5 times, 8 times, and any value within the range defined by any two of the values, preferably 2-5 times.

[0051] As a specific embodiment of the above preparation method of the present application, the second calcination is carried out in a 100% steam atmosphere at a temperature of 400-700°C, preferably 550-680°C, for a time of 0.1-10 h, preferably 0.5-5 h.

[0052] As a specific embodiment of the above preparation method of the present application, the low-sulfate rare earth modified Y-type molecular sieve has a SO4 2- content of ≤1.0 wt%, more preferably ≤0.5 wt%, and further preferably 0.01-0.45 wt%.

[0053] As a specific embodiment of the above preparation method of the present application, the catalyst shaping in step (2) comprises:

[0054] The Na-containing catalyst is prepared by mixing water, 28-42 parts of the low-sulfate rare earth modified Y-type molecular sieve, 2-15 parts of ZSM-5 molecular sieve, 30-65 parts of clay, and 6.5-30 parts of a binder to a total of 100 parts of the dry mass of the Na-containing catalyst, uniformly mixing, forming a slurry with a solid content of 25-50 wt%, homogenizing, spray forming, and third calcination.

[0055] Preferably, 28-38 parts of the low-sulfate rare earth modified Y-type molecular sieve, 3-8 parts of the ZSM-5 molecular sieve, 35-50 parts of the clay, and 7-27 parts of the binder are uniformly mixed with 100 parts of the catalyst dry base mass, to form a slurry with a solid content of 35-45 wt%, which is then homogenized, spray-formed, and thirdly calcined to obtain the Na-containing catalyst.

[0056] As a specific embodiment of the above preparation method of the present application, the ZSM-5 molecular sieve comprises at least one of HZSM-5, phosphorus-modified ZSM-5, etc.

[0057] As a specific embodiment of the above preparation method of the present application, the clay comprises at least one of kaolin, halloysite, porous stone, diatomite, water bubble stone, etc.

[0058] As a specific embodiment of the above preparation method of the present application, the binder comprises at least one of aluminum sol, acidified pseudo-boehmite, acidic silicon sol, phosphorus-aluminum sol, etc.

[0059] As a specific embodiment of the above preparation method of the present application, the third calcination conditions comprise: air atmosphere; temperature of 420-480℃; and time of 20-50 min.

[0060] As a specific embodiment of the above preparation method of the present application, in step (3), 1-3 wt% of the phosphorus-containing substance calculated as P2O5 is added to the Na-containing catalyst dry base total weight of 100% to modify the Na-containing catalyst.

[0061] Preferably, 1.3-2.5 wt% of the phosphorus-containing substance calculated as P2O5 is added to the Na-containing catalyst dry base total weight of 100% to modify the Na-containing catalyst.

[0062] As a specific embodiment of the above preparation method of the present application, the weight ratio of water to Na-containing catalyst particles is 0.5-35:1.

[0063] As a specific embodiment of the above preparation method of the present application, the water washing temperature is 20-100℃, and the time is 0.1-0.3 h.

[0064] As a specific embodiment of the above preparation method of the present application, the phosphorus-containing substance comprises at least one of phosphoric acid, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, etc.

[0065] On the other hand, the present application also provides a propylene-rich catalytic cracking catalyst, wherein the propylene-rich catalytic cracking catalyst is prepared by the above preparation method of the propylene-rich catalytic cracking catalyst.

[0066] As a specific embodiment of the above-mentioned propylene-rich catalytic cracking catalyst of the present application, it comprises 28-42 wt% of low-sulfate rare earth modified Y-type molecular sieve, 2-15 wt% of ZSM-5 molecular sieve, 6.5-30 wt% of binder, 30-65 wt% of clay and 1-3 wt% of phosphorus-containing compound calculated as P2O5, based on the total weight of the propylene-rich catalytic cracking catalyst being 100%.

[0067] In another aspect, the present application also provides the use of the above-mentioned propylene-rich catalytic cracking catalyst in the catalytic cracking of heavy oil to produce propylene.

[0068] Compared with the prior art, the present application has the following beneficial technical effects:

[0069] The propylene-rich catalytic cracking catalyst provided by the present application contains low-sulfate rare earth modified Y-type molecular sieve. In the preparation of the low-sulfate rare earth modified Y-type molecular sieve, industrial cheap and harmless ammonium sulfate is used as the exchange agent, and a precipitant such as ammonium oxalate, ammonium carbonate or ammonia water is added before the ammonium sulfate exchange after the rare earth ion exchange. The added precipitant preferentially generates a precipitated precursor of rare earth oxide with the rare earth ions, avoiding the generation of a precipitate from the free RE ions and sulfate in the exchange system solution, on the surface of the molecular sieve or in the supercage during the subsequent ammonium sulfate exchange to reduce sodium, thereby achieving the purpose of reducing the sulfate content, improving the crystallinity and stability of the molecular sieve, and also improving the utilization rate of rare earth.

[0070] Since Y-type molecular sieve is the main active component of catalytic cracking catalyst, its performance determines the performance of the catalytic cracking catalyst. The present application reduces the sulfate content of Y-type molecular sieve, improves its crystallinity and stability by the above-mentioned preparation method, so that when the low-sulfate rare earth modified Y-type molecular sieve is used as the active component of the catalytic cracking catalyst, more acidic centers can be provided, and the cracking activity and hydrothermal stability of the catalyst are also improved accordingly, so that under the catalytic cracking conditions, heavy oil macromolecules can be converted into a large amount of gasoline intermediate fraction molecules, more cracking raw materials are provided for ZSM-5, and the propylene yield is significantly improved.

[0071] In summary, the low-sulfate rare earth modified Y-type molecular sieve prepared by the present application has the advantages of low sulfate content, high crystallinity and good stability, and when it is used as the active component of the catalytic cracking catalyst, the propylene-rich catalytic cracking catalyst has the characteristics of high propylene yield, strong heavy oil conversion capacity and high liquid yield. DETAILED DESCRIPTION

[0072] It has to be understood that the terms "comprising", "including", "containing", "characterized by" and any other variation thereof, are intended to cover a non-exclusive inclusion, such that processes, methods, articles, or apparatuses that comprise, include, contain or are characterized by a list of steps or elements can comprise, include, contain or be characterized by only those steps or elements or other steps or elements not expressly listed or inherent to such processes, methods, articles, or apparatuses.

[0073] The ranges disclosed herein are given in their broadest form. They can be narrower, i.e. one or more lower limits and one or more upper limits. A given range is defined by selecting a lower limit and an upper limit. The selected lower limit and upper limit define the boundaries of a particular range. All ranges defined in this way are combinable, i.e. any lower limit can be combined with any upper limit to form a range. For example, where ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that ranges of 60-110 and 80-120 are also contemplated. Furthermore, if a minimum range value of 1 and 2 is listed and a maximum range value of 3, 4 and 5 is listed, then the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.

[0074] In the present application, unless otherwise stated, the numerical range "a-b" represents a shorthand for the full set of real combinations of a to b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed in the present application, "0-5" is just a shorthand for these numerical combinations.

[0075] In the present application, unless otherwise stated, all embodiments mentioned in the present application and preferred embodiments can be combined with each other to form new technical solutions.

[0076] In the present application, unless otherwise stated, all technical features mentioned in the present application and preferred features can be combined with each other to form new technical solutions.

[0077] In the present application, unless otherwise stated, all steps mentioned in the present application can be performed in sequence or randomly, but preferably in sequence. For example, the method comprises steps (a) and (b), which means that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, the method further comprises step (c), which means that step (c) can be added to the method in any order, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0078] In the present application, "first", "second", and "third" and the like do not indicate the order of precedence, nor do they limit the respective materials or steps, but are merely used to distinguish that this is not the same step or material. For example, "first" and "second" in "first ammonium sulfate exchange" and "second ammonium sulfate exchange" are merely used to indicate that this is not the same ammonium sulfate exchange.

[0079] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application is further described in detail below in combination with the accompanying tables and examples. The examples described below are part of the examples of the present application, but not all of the examples, and are merely used to illustrate the present application, and should not be regarded as limiting the scope of the present application. Based on the examples in the present application, all other examples obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present application. If the specific conditions are not indicated in the examples, the conventional conditions or the conditions recommended by the manufacturers are used. If the manufacturers of the reagents or instruments are not indicated, they are all conventional products that can be obtained by market purchase.

[0080] (I) The analysis and evaluation methods used in the examples are as follows:

[0081] 1. Cell constant (a0): X-ray diffraction method.

[0082] 2. Crystallinity (C / C0): X-ray diffraction method.

[0083] 3. Si / Al ratio: X-ray diffraction method.

[0084] 4. Na2O content: XRF fluorescence method.

[0085] 5. RE2O3 content: XRF fluorescence method.

[0086] 6. P2O5 content: XRF fluorescence method.

[0087] 7. Sulfate content: XRF fluorescence method.

[0088] 8. Micro-activity: The sample is pretreated at 800°C under 100% steam for different times. The reaction raw material is Dagang light diesel oil, the reaction temperature is 460°C, the reaction time is 70 seconds, the catalyst loading is 5.0 grams, the weight ratio of catalyst to oil is 3.2, and the total conversion rate is used as the micro-activity.

[0089] 9. ACE heavy oil micro-reactor: the reaction temperature is 530°C, the catalyst to oil ratio is 5, and the raw oil is Lanzhou Petrochemical 3 million heavy oil catalytic unit raw oil.

[0090] (II) The specifications of the raw materials used in the examples are as follows:

[0091] 1. NaY molecular sieve: NaY (Si / Al ratio 5.1, crystallinity 95%), produced by Changting Catalyst Co., Ltd.

[0092] 2. Rare earth precursor: chlorinated rare earth, nitric acid rare earth, both are industrial products, from Catalyst Factory of Lanzhou Petrochemical Company.

[0093] 3. Ammonium sulfate, ammonium oxalate, ammonium carbonate, ammonium bicarbonate, ammonia, urea, ammonium acetate, ammonium chloride, ammonium nitrate, ammonium phosphate, diammonium hydrogen phosphate, monobasic ammonium phosphate, etc. are all of analytical purity.

[0094] 4. Pseudo-boehmite (ignition loss 36.7%), kaolin (ignition loss 18.4%), halloysite (ignition loss 23.2%), porous stone (ignition loss 18.2%), diatomite (ignition loss 23.6%), water bubble stone (ignition loss 25.3%), macroporous alumina (ignition loss 16.8%), boehmite (ignition loss 14.5%), P-modified ZSM-5 (ignition loss 5.6%), macroporous silica-alumina material (solid content 15.4%, pore volume 1.15 mL / g) solids; aluminum sol, containing 22.6wt% alumina; silica sol, containing 30.5wt% silicon oxide, all are industrial qualified products.

[0095] Preparation Example 1

[0096] The present preparation example provides a low-sulfate rare earth modified Y-type molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0097] a. 1000g (dry basis) of NaY molecular sieve is slurried with 5L of deionized water, then 0.537L (calculated as La2O3) of LaCl3 solution with a concentration of 298g / L is added (La2O3 content is 0.98mol) to perform rare earth ion exchange (temperature is 80℃, pH is 3.6, time is 0.5h), to obtain a rare earth ion exchange slurry; wherein the content of LaCl3 (calculated as La2O3) in the NaY molecular sieve (dry basis) is 16wt%; 3+

[0098] b. (32g, 0.225mol) of ammonium oxalate monohydrate is added to the above rare earth ion exchange slurry, so that 2.4wt% of La3+ in the rare earth ion exchange slurry is precipitated (temperature is 80℃, time is 0.5h), to obtain a first precipitation slurry; 3+

[0099] c. The above first precipitation slurry is filtered and dried, 0.833L of ammonium sulfate aqueous solution with a concentration of 180g / L is added, exchanged at 60℃ for 1h, dried, washed with 3L of water, then calcined at 550℃ for 2h in a 100% water vapor atmosphere, to obtain a first-interaction-first-calcination molecular sieve dry powder;

[0100] ​​d. 1000 g (dry basis) of the one-exchange one-calcined molecular sieve dry powder was slurried with 5 L of deionized water, and then (25.6 g, 0.18 mol) of ammonium oxalate monohydrate was added to make 2 wt% of La 3+ After the second precipitation (at 25 °C for 0.5 h), 0.6 L of a 250 g / L ammonium sulfate aqueous solution was added, and ion exchange was performed at 80 °C for 1.5 h. After filtration, the product was dried, washed with 5 L of water, and then calcined at 650 °C for 2 h in a 100% water vapor atmosphere to obtain a low-sulfate rare earth modified Y-type molecular sieve, which was denoted as Z1.

[0101] Preparation Example 2

[0102] The present preparation example provides a low-sulfate rare earth modified Y-type molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0103] a. 1000 g (dry basis) of NaY molecular sieve was slurried with 5 L of deionized water, and then 0.358 L of a La(NO3)3 solution (calculated as La2O3) with a concentration of 280 g / L was added to perform rare earth ion exchange (at 50 °C, pH 4.0, for 1.5 h), to obtain a rare earth ion exchange slurry; wherein the content of La(NO3)3 (calculated as La2O3) in the NaY molecular sieve (dry basis) was 10 wt%; 3+ The rare earth ion exchange slurry was obtained by rare earth ion exchange (at 50 °C, pH 4.0, for 1.5 h) with 0.615 mol of La(NO3)3 (calculated as La2O3); wherein the content of La(NO3)3 (calculated as La2O3) in the NaY molecular sieve (dry basis) was 10 wt%;

[0104] b. (25.6 g, 0.18 mol) of ammonium oxalate monohydrate was added to make 2 wt% of La 3+ The first precipitation slurry was obtained by first precipitation (at 50 °C for 0.5 h);

[0105] c. The first precipitation slurry was filtered, dried, and then 1.111 L of a 180 g / L ammonium sulfate aqueous solution was added to perform ion exchange at 80 °C for 1 h. After drying, the product was washed with 3 L of water, and then calcined at 600 °C for 2 h in a 100% water vapor atmosphere to obtain a one-exchange one-calcined molecular sieve dry powder;

[0106] d. 1000 g (dry basis) of the one-exchange one-calcined molecular sieve dry powder was slurried with 5 L of deionized water, and then (13 g, 0.135 mol) of ammonium carbonate was added to make 1.5 wt% of La 3+ The low-sulfate rare earth modified Y-type molecular sieve was obtained by second precipitation (at 25 °C for 0.5 h), followed by the addition of 1.666 L of a 120 g / L ammonium sulfate aqueous solution, ion exchange at 50 °C for 1 h, filtration, drying, washing with 2 L of water, and calcination at 650 °C for 2.5 h in a 100% water vapor atmosphere.

[0107] Preparation Example 3

[0108] The present preparation example provides a low-sulfate rare earth modified Y-type molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0109] a. After 1000 g (dry base weight) of NaY molecular sieve is slurried with 5 L of deionized water, 0.407 L of YCl3 solution (Y2O3 basis) with a concentration of 246 g / L is added to perform rare earth ion exchange (temperature is 60°C, pH is 4.2, and time is 1 h) to obtain a rare earth ion exchange slurry; the content of YCl3 (Y2O3 basis) in the NaY molecular sieve (dry basis) is 5.97 wt.%; and the content of RECl3 (RE2O3 basis) in the NaY molecular sieve (dry basis) is 5.97 wt.%. 3+

[0110] b. After (32 g, 0.225 mol) of ammonium oxalate monohydrate is added, 1.7 wt.% of Y 3+ of the rare earth ion exchange slurry is precipitated (temperature is 60°C, and time is 0.5 h) to obtain a first precipitation slurry;

[0111] c. The first precipitation slurry is filtered, drained, 1.389 L of an ammonium sulfate aqueous solution with a concentration of 180 g / L is added, and exchanged at 60°C for 1.5 h, drained, washed with 3 L of water, and then calcined at 680°C for 1.5 h in a 100% water vapor atmosphere to obtain a first exchange and calcination molecular sieve dry powder;

[0112] d. After 1000 g (dry base weight) of the first exchange and calcination molecular sieve dry powder is slurried with 5 L of deionized water, (22.6 g, 0.16 mol) of ammonium oxalate monohydrate is added, and 1.2 wt.% of Y 3+ of the first exchange and calcination molecular sieve dry powder is precipitated (temperature is 25°C, and time is 0.5 h), 1.389 L of an ammonium sulfate aqueous solution with a concentration of 180 g / L is added, and exchanged at 50°C for 1 h, filtered, drained, washed with 3 L of water, and then calcined at 650°C for 2 h in a 100% water vapor atmosphere to obtain a low-sulfate rare earth modified Y-type molecular sieve, which is denoted as Z3.

[0113] Preparation Example 4

[0114] The present preparation example provides a low-sulfate rare earth modified Y-type molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0115] a. After 1000 g (dry base weight) of NaY molecular sieve is slurried with 5 L of deionized water, 0.43 L of a mixed RECl3 solution (Ce2O3 and La2O3 weight ratio is 6:4, RE 3+ ​The rare earth ion exchange (temperature 60°C, pH 3.8, time 1 h) was carried out on the slurry of 0.9287 mol of the NaY molecular sieve to obtain a rare earth ion exchange slurry; wherein the content of RECl3 in terms of RE2O3 in the NaY molecular sieve in terms of dry basis was 14 wt%;

[0116] b. Adding (25.6 g, 0.18 mol) of ammonium oxalate monohydrate and 5 mL of 28% industrial ammonia water to make 2.4 wt% of RE 3+ The first precipitation (temperature 60°C, time 0.5 h) was carried out to obtain a first precipitation slurry;

[0117] c. Filtering and drying the first precipitation slurry, adding 1.222 L of 180 g / L ammonium sulfate aqueous solution, and exchanging at 100°C for 0.5 h, drying, adding 5 L of water for leaching, and then calcining at 580°C for 2 h in a 100% water vapor atmosphere to obtain a one-interaction-one-calcination molecular sieve dry powder;

[0118] d. Slushing the above 1000 g (dry weight) of one-interaction-one-calcination molecular sieve dry powder with 5 L of deionized water, and then adding (18 g, 0.187 mol) of ammonium carbonate to make 1.8 wt% of RE 3+ After the second precipitation (temperature 25°C, time 0.5 h), adding 1 L of 120 g / L ammonium sulfate aqueous solution, exchanging at 25°C for 1 h, filtering, drying, adding 4 L of water for leaching, and calcining at 680°C for 2 h in a 100% water vapor atmosphere to obtain a low-sulfate rare earth modified Y-type molecular sieve, which is denoted as modified molecular sieve Z4.

[0119] Preparation Example 5

[0120] The present preparation example provides a low-sulfate rare earth modified Y-type molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0121] According to the method of Preparation Example 1, except that in step b, (32 g, 0.225 mol) of ammonium oxalate monohydrate is replaced by (12.8 g, 0.09 mol) of ammonium oxalate monohydrate to make 1 wt% of La 3+ The first precipitation (temperature 80°C, time 0.5 h) was carried out; the rest of the conditions were the same to obtain a low-sulfate rare earth modified Y-type molecular sieve, which is denoted as Z5.

[0122] Preparation Example 6

[0123] The present preparation example provides a low-sulfate rare earth modified Y-type molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0124] According to the method of Preparation Example 1, except that in step d, (25.6 g, 0.18 mol) of ammonium oxalate monohydrate is replaced by (6.4 g, 0.045 mol) of ammonium oxalate monohydrate, and 0.5 wt% of La in the above one-exchange-one-calcination molecular sieve dry powder 3+ A second precipitation (at 25°C for 0.5 h) is performed; the rest of the conditions are the same, to obtain a low-sulfate rare earth modified Y-type molecular sieve, denoted as Z6.

[0125] Comparative Preparation Example 7

[0126] This comparative preparation example provides a rare earth modified Y-type molecular sieve, which is prepared according to the method disclosed in CN200610087535.2, and the preparation method comprises the following specific steps:

[0127] Take 1000 g (dry basis) of NaY molecular sieve, pulp with 8 L of deionized water, then add 0.385 L of LaCl3 solution with a concentration of 312 g / L (calculated as La2O3), and then add 240 g of aluminum sulfate, exchange at 90°C for 1 h, then add 75 g of ammonium bicarbonate, constant temperature stirring for 0.25 h, then filter, 5 L of water is used for washing, and then the filter cake is calcined at 600°C in a 100% steam atmosphere for 2 hours to obtain one-exchange-one-calcination molecular sieve dry powder;

[0128] Take 1000 g (dry basis) of the one-exchange-one-calcination molecular sieve dry powder, pulp with 6 L of deionized water, then add 300 g of ammonium sulfate, exchange at 75°C for 1 h, filter, 6 L of water is used for washing, and then the filter cake is dried to obtain a rare earth modified molecular sieve, denoted as DZ1.

[0129] Comparative Preparation Example 8

[0130] This comparative preparation example provides a rare earth modified Y-type molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0131] According to the method of Preparation Example 1, except that in step d, (32 g, 0.225 mol) of ammonium oxalate monohydrate is not added, and the rest of the conditions are the same, to obtain a rare earth modified molecular sieve, denoted as DZ2.

[0132] Comparative Preparation Example 9

[0133] This comparative preparation example provides a rare earth modified Y-type molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0134] According to the method of Preparation Example 2, except that in step b, (25.6 g, 0.18 mol) of ammonium oxalate monohydrate is not added, and the rest of the conditions are the same, to obtain a rare earth modified molecular sieve, denoted as DZ3.

[0135] Comparative Preparation Example 10

[0136] The present comparative preparation example provides a rare earth modified Y-type molecular sieve which is prepared by a preparation method comprising the following specific steps:

[0137] According to the method of Preparation Example 4, except that in step b, (25.6 g, 0.18 mol) of ammonium oxalate monohydrate and 5 mL of 28% industrial ammonia water are not added, and in step d, (18 g, 0.187 mol) of ammonium carbonate is not added, and the remaining conditions are the same, a rare earth modified molecular sieve is obtained, which is denoted as DZ4.

[0138] The physical property parameters of the rare earth modified Y-type molecular sieves (Z1-Z6 and DZ1-DZ4) prepared in Preparation Examples 1-6 and Comparative Preparation Examples 7-10 are all listed in Table 1.

[0139] Table 1

[0140]

[0141]

[0142] From the data in Table 1, it can be seen that the rare earth modified Y-type molecular sieve prepared by the modification process provided by the present application has a higher rare earth utilization rate, a lower sulfate content and a higher crystallinity compared with Comparative Preparation Examples 7-10.

[0143] Compared with Preparation Example 5, the scheme of Preparation Example 1 by adjusting the amount of the first precipitant so that the content of the first precipitated rare earth ions is within the preferred protection range, the modified Y-type molecular sieve obtained has a lower sulfate content and a slightly higher crystallinity.

[0144] Compared with Preparation Example 6, the scheme of Preparation Example 1 by adjusting the amount of the second precipitant so that the content of the second precipitated rare earth ions is within the preferred protection range, the modified Y-type molecular sieve obtained also has a lower sulfate content and a slightly higher crystallinity.

[0145] Test Example 1

[0146] This test example respectively tests the hydrothermal stability of the rare earth modified Y-type molecular sieves (Z1-Z6 and DZ1-DZ4) prepared in Preparation Examples 1-6 and Comparative Preparation Examples 7-10, including: 100 g (dry basis) of the rare earth modified Y-type molecular sieves (Z1-Z6 and DZ1-DZ4) are respectively pressed into tablets, crushed into 20-40 mesh particles, and after aging for 10 h under the conditions of 100% water vapor and 800°C on a fixed bed hydrothermal treatment device, the microactivity index (MA) is measured on a catalytic cracking automatic micro-reaction activity evaluation instrument, the reaction raw material is Dagang light diesel oil, the reaction temperature is 460°C, the reaction time is 70 seconds, the catalyst loading is 5.0 grams, the weight ratio of catalyst to oil is 3.2, and the total conversion rate is used as the micro-reaction activity, and the test results are all listed in Table 2.

[0147] Table 2

[0148]

[0149]

[0150] From the data in Table 2, it can be seen that, compared with Comparative Preparation Examples 7-10, the rare earth modified Y-type molecular sieves prepared in Preparation Examples 1-6 have obviously higher micro- reaction activities (i.e., have higher MA1 values) after being aged at 100% steam and 800°C for 10 h. Therefore, the rare earth modified Y-type molecular sieves prepared by the modification process provided in the present application have better hydrothermal stability and cracking activity.

[0151] Example 1

[0152] The present example provides a propylene-rich catalytic cracking catalyst which is prepared by a preparation method comprising the following specific steps:

[0153] 1) The above low-sulfate rare earth modified Y-type molecular sieve Z1, P-modified ZSM-5, aluminum sol, acidified pseudo-boehmite, kaolin and water are mixed at 25°C for 1 h to obtain a slurry with a solid content of 45 wt%; wherein the weight ratio of the low-sulfate rare earth modified Y-type molecular sieve Z1, P-modified ZSM-5, aluminum sol, acidified pseudo-boehmite, kaolin is 32:5:8.5:12:42.5;

[0154] 2) The above slurry is sequentially subjected to homogenization, spray forming, and calcination at 450°C in air for 30 min to obtain a Na-containing catalyst;

[0155] 3) The Na-containing catalyst and water are mixed to form a slurry with a solid content of 20 wt% of the catalyst precursor (Na-containing catalyst), and then mixed with diammonium hydrogen phosphate for sodium reduction modification, and then sequentially subjected to filtration, 5-fold water washing (water washing temperature is 85°C, and time is 0.2 h), and 100°C drying for 12 h to obtain a propylene-rich catalytic cracking catalyst, which is denoted as C1;

[0156] The weight ratio of the diammonium hydrogen phosphate (P2O5 basis) and the slurry of the catalyst precursor, i.e., the Na-containing catalyst, is 1.3:100, i.e., the weight ratio of the diammonium hydrogen phosphate (P2O5 basis) and the dry basis Na-containing catalyst is 1.3:100.

[0157] The Na content in C1 is 0.12 wt% (calculated as Na2O), and the P2O5 content is 1.26 wt%. + The Na content in C1 is 0.12 wt% (calculated as Na2O), and the P2O5 content is 1.26 wt%.

[0158] Example 2

[0159] The embodiment provides a propylene-rich catalytic cracking catalyst which is prepared by a preparation method comprising the following specific steps:

[0160] 1) mixing the low-sulfate rare earth modified Y-type molecular sieve Z2, P modified ZSM-5, aluminum sol, acidified pseudo-boehmite, kaolin and water at 25 DEG C for 1h to obtain a slurry with a solid content of 45wt%; wherein the weight ratio of the low-sulfate rare earth modified Y-type molecular sieve Z2, P modified ZSM-5, aluminum sol, acidified pseudo-boehmite and kaolin is 38:5:10:10:37;

[0161] 2) sequentially performing homogenization, spray forming, and 470 DEG C calcination in an air atmosphere for 20min on the slurry to obtain a Na-containing catalyst;

[0162] 3) mixing the Na-containing catalyst and water to form a slurry with a solid content of 25wt% of the catalyst precursor (Na-containing catalyst), mixing with diammonium hydrogen phosphate to perform sodium reduction modification, and then sequentially performing filtration, 8 times of water washing (water washing temperature is 70 DEG C, and time is 0.25h), and 120 DEG C drying for 8h to obtain the propylene-rich catalytic cracking catalyst, which is recorded as C2.

[0163] The weight ratio of the diammonium hydrogen phosphate (P2O5) and the slurry of the catalyst precursor, namely the Na-containing catalyst, is 2.1:100, that is, the weight ratio of the diammonium hydrogen phosphate (P2O5) and the dry base Na-containing catalyst is 2.1:100.

[0164] The Na content of C2 is 0.09wt% in terms of Na2O, and the P2O5 content is 2.08wt%. + The Na content of C2 is 0.09wt% in terms of Na2O, and the P2O5 content is 2.08wt%.

[0165] Embodiment 3

[0166] The embodiment provides a propylene-rich catalytic cracking catalyst which is prepared by a preparation method comprising the following specific steps:

[0167] 1) mixing the low-sulfate rare earth modified Y-type molecular sieve Z2, P modified ZSM-5, aluminum sol, acidified pseudo-boehmite, kaolin and water at 25 DEG C for 1h to obtain a slurry with a solid content of 45wt%; wherein the weight ratio of the low-sulfate rare earth modified Y-type molecular sieve Z2, P modified ZSM-5, aluminum sol, acidified pseudo-boehmite and kaolin is 38:5:10:10:37;

[0168] 2) sequentially performing homogenization, spray forming, and 470 DEG C calcination in an air atmosphere for 20min on the slurry to obtain a Na-containing catalyst;

[0169] 3) mixing the Na-containing catalyst and water to form a slurry containing the catalyst precursor with a solid content of 20wt%, and then mixing with diammonium hydrogen phosphate to perform sodium reduction modification, and then sequentially filtering, 5 times of water washing (water washing temperature is 95℃, and time is 0.3h), and drying at 110℃ for 10h to obtain a propylene-rich catalytic cracking catalyst, denoted as C3.

[0170] The weight ratio of the diammonium hydrogen phosphate (P2O5) to the slurry containing the catalyst precursor calculated based on the catalyst precursor is 2.5:100, that is, the weight ratio of the diammonium hydrogen phosphate (P2O5) to the Na-containing catalyst dry basis is 2.5:100.

[0171] The Na content in C3 is 0.06wt% calculated based on Na2O. + The P2O5 content is 2.39wt%.

[0172] Example 4

[0173] The present example provides a propylene-rich catalytic cracking catalyst, which is prepared by a preparation method comprising the following specific steps:

[0174] 1) mixing the above low-sulfate rare earth modified Y-type molecular sieve Z4, P-modified ZSM-5, aluminum sol, acidified pseudo-boehmite, kaolin and water at 25℃ for 1h to obtain a slurry with a solid content of 45wt%; wherein the weight ratio of Z4, P-modified ZSM-5, aluminum sol, acidified pseudo-boehmite, kaolin is 33:5:7:20:35;

[0175] 2) sequentially performing homogenization, spray forming and 450 air atmosphere roasting for 30min on the above slurry to obtain a Na-containing catalyst, that is, a catalyst precursor;

[0176] 3) mixing the Na-containing catalyst and water to form a slurry containing the catalyst precursor with a solid content of 20wt%, and then mixing with diammonium hydrogen phosphate to perform sodium reduction modification, and then sequentially filtering, 5 times of water washing (water washing temperature is 95℃, and time is 0.3h), and drying at 110℃ for 10h to obtain a propylene-rich catalytic cracking catalyst, denoted as C3.

[0177] The weight ratio of the diammonium hydrogen phosphate (P2O5) to the slurry containing the catalyst precursor calculated based on the catalyst precursor is 2.5:100, that is, the weight ratio of the diammonium hydrogen phosphate (P2O5) to the Na-containing catalyst dry basis is 2.5:100.

[0178] The Na content in C3 is 0.06wt% calculated based on Na2O. + The P2O5 content is 2.39wt%.

[0179] Example 5

[0180] The embodiment provides a propylene-catalytic-cracking catalyst with high yield, which is prepared by a preparation method comprising the following specific steps:

[0181] According to the method in Embodiment 1, except that Z1 is replaced by Z5 in step 1), the remaining conditions are the same, and a propylene-catalytic-cracking catalyst with high yield is obtained, which is recorded as C5.

[0182] The Na content in C5 is 0.14wt%, and the P2O5 content is 1.28wt%. + The Na content in C5 is 0.14wt%, and the P2O5 content is 1.28wt%.

[0183] Embodiment 6

[0184] The embodiment provides a propylene-catalytic-cracking catalyst with high yield, which is prepared by a preparation method comprising the following specific steps:

[0185] According to the method in Embodiment 1, except that Z1 is replaced by Z6 in step 1), the remaining conditions are the same, and a propylene-catalytic-cracking catalyst with high yield is obtained, which is recorded as C6.

[0186] The Na content in C6 is 0.13wt%, and the P2O5 content is 1.29wt%. + The Na content in C6 is 0.13wt%, and the P2O5 content is 1.29wt%.

[0187] Comparative Example 1

[0188] The comparative example provides a propylene-catalytic-cracking catalyst, which is prepared by a preparation method comprising the following specific steps:

[0189] 1) The rare earth modified molecular sieve DZ1, the P modified ZSM-5, the aluminum sol, the acidified pseudo-boehmite, the kaolin and the water are mixed at 25 DEG C for 1h to obtain a slurry with a solid content of 45wt%; wherein the weight ratio of the rare earth modified molecular sieve DZ1, the P modified ZSM-5, the aluminum sol, the acidified pseudo-boehmite and the kaolin is 34:5:9:10:42;

[0190] 2) The slurry is sequentially subjected to homogenization, spray forming and calcination at 450 DEG C for 30min to obtain a Na-containing catalyst, namely a catalyst precursor;

[0191] 3) The Na-containing catalyst and the water are mixed to form a slurry with a solid content of 20wt% containing the catalyst precursor, and then the slurry is mixed with diammonium hydrogen phosphate to perform sodium reduction modification, and then is sequentially subjected to filtration, 4 times of water washing (the water washing temperature is 50 DEG C, and the time is 0.25h), and 105 DEG C drying for 10h to obtain a propylene-catalytic-cracking catalyst, which is recorded as DC1;

[0192] The weight ratio of diammonium hydrogen phosphate (calculated as P2O5) to the slurry containing catalyst precursor calculated as catalyst precursor is 1.8:100, i.e. the weight ratio of diammonium hydrogen phosphate (calculated as P2O5) to Na-containing catalyst dry basis is 1.8:100.

[0193] Na in DC1 + The content of Na is 0.21wt%, and the content of P2O5 is 1.75wt%.

[0194] Comparative Example 2

[0195] The present comparative example provides a propylene catalytic cracking catalyst, which is prepared by a preparation method comprising the following specific steps:

[0196] 1) The rare earth modified molecular sieve DZ2, P modified ZSM-5, aluminum sol, acidified pseudo-boehmite, kaolin and water are mixed at 25℃ for 1h to obtain a slurry with a solid content of 45wt%; wherein the weight ratio of rare earth modified molecular sieve DZ2, P modified ZSM-5, aluminum sol, acidified pseudo-boehmite, kaolin is 30:5:7.5:15:42.5;

[0197] 2) The above slurry is sequentially subjected to homogenization, spray forming, and calcination at 470℃ for 30min to obtain a Na-containing catalyst, i.e. a catalyst precursor;

[0198] 3) The Na-containing catalyst and water are mixed to form a slurry containing catalyst precursor with a solid content of 20wt%, and then mixed with diammonium hydrogen phosphate for sodium reduction modification, and then sequentially subjected to filtration, 4 times water washing (water washing temperature is 60℃, time is 0.2h), and 120℃ drying for 10h to obtain a propylene catalytic cracking catalyst, which is recorded as DC2;

[0199] The weight ratio of diammonium hydrogen phosphate (calculated as P2O5) to the slurry containing catalyst precursor calculated as catalyst precursor is 1.55:100, i.e. the weight ratio of diammonium hydrogen phosphate (calculated as P2O5) to Na-containing catalyst dry basis is 1.55:100.

[0200] Na in DC2 + The content of Na is 0.22wt%, and the content of P2O5 is 1.45wt%.

[0201] Comparative Example 3

[0202] The present comparative example provides a propylene catalytic cracking catalyst, which is prepared by a preparation method comprising the following specific steps:

[0203] 1) The rare earth modified molecular sieve DZ3, P modified ZSM-5, aluminum sol, acidified pseudo-boehmite, kaolin and water are mixed at 25℃ for 1h to obtain a slurry with a solid content of 45wt%; wherein the weight ratio of the rare earth modified molecular sieve DZ3, P modified ZSM-5, aluminum sol, acidified pseudo-boehmite, kaolin is 36:5:9:13:37;

[0204] 2) The above slurry is subjected to homogenization, spray forming and calcination at 430℃ for 45min in sequence to obtain a Na-containing catalyst, i.e. a catalyst precursor;

[0205] 3) The Na-containing catalyst is mixed with water to form a slurry containing the catalyst precursor with a solid content of 20wt%, and then mixed with diammonium hydrogen phosphate for sodium reduction modification, and then subjected to filtration and 6 times water washing (water washing temperature is 40℃, and the time is 0.3h) in sequence, and then dried at 100℃ for 10h to obtain a propylene catalytic cracking catalyst, which is denoted as DC3.

[0206] The weight ratio of the diammonium hydrogen phosphate (P2O5) and the slurry containing the catalyst precursor based on the catalyst precursor is 2.1:100, i.e. the weight ratio of the diammonium hydrogen phosphate (P2O5) and the Na-containing catalyst dry basis is 2.1:100.

[0207] The Na content in DC3 is 0.23wt% based on Na2O, and the P2O5 content is 1.98wt%. + The Na content in DC3 is 0.23wt% based on Na2O, and the P2O5 content is 1.98wt%.

[0208] Comparative Example 4

[0209] The comparative example provides a propylene catalytic cracking catalyst, which is prepared by a preparation method comprising the following specific steps:

[0210] According to the method of Example 1, except that Z1 is replaced by DZ4, and the other conditions are the same, a propylene catalytic cracking catalyst is obtained, which is denoted as DC4.

[0211] The Na content in DC4 is 0.18wt% based on Na2O, and the P2O5 content is 1.27wt%. + The Na content in DC4 is 0.18wt% based on Na2O, and the P2O5 content is 1.27wt%.

[0212] Test Example 2

[0213] The catalytic cracking catalysts (C1-C6 and DC1-DC4) prepared in Examples 1-6 and Comparative Examples 1-4 are respectively subjected to reaction performance tests, including:

[0214] The catalytic cracking catalysts (C1-C6 and DC1-DC4) and the Lanzhou Petrochemical 3 million heavy oil catalytic unit feed oil were respectively added into the ACE heavy oil micro-reactor, and catalytic cracking reaction was carried out (the temperature was 530 DEG C, the catalyst / oil ratio was 5, that is, the weight ratio of the catalytic cracking catalyst and the Lanzhou Petrochemical 3 million heavy oil catalytic unit feed oil was 5:1), and the catalytic cracking product was obtained after the reaction was completed.

[0215] The catalytic cracking product includes dry gas, liquefied gas, gasoline, diesel, heavy oil and coke, and the test results are listed in Table 3.

[0216] Table 3

[0217]

[0218]

[0219] Note: 1-the conversion rate of the Lanzhou Petrochemical 3 million heavy oil catalytic unit feed oil; 2-refers to the sum of the yield of liquefied gas, gasoline and diesel.

[0220] From the data in Table 3, compared with the comparative examples 1-4, the catalytic cracking catalysts prepared in the examples 1-6 of the present application have excellent heavy oil cracking activity, propylene yield performance and high value-added product selectivity, that is, have high heavy oil conversion rate, propylene yield and total liquid yield.

[0221] The above is only a specific embodiment of the present application, and cannot limit the scope of the application. Therefore, the replacement of equivalent components or equivalent changes and modifications made within the scope of the present application should still be within the scope of the present patent. In addition, the technical features in the present application can be freely combined with each other, and the technical features can be freely combined with each other.

Claims

1. A process for the preparation of a propylene-rich catalytic cracking catalyst, characterized in that, The preparation method comprises: (1) preparation of low-sulfate rare earth modified Y-type molecular sieve: Step one: rare earth ion exchange of Na-type molecular sieve to obtain rare earth ion exchange slurry; Step two: addition of first precipitant to cause first precipitation of rare earth ions in the rare earth ion exchange slurry to obtain first precipitation slurry; Step three: the first precipitation slurry is sequentially subjected to filtration, first ammonium sulfate exchange, first water washing, and first calcination to obtain one-exchange-one-calcination molecular sieve dry powder; wherein the first calcination conditions comprise 100% water vapor atmosphere, temperature of 400-700℃, and time of 0.1-5h; Step four: slurry preparation of the one-exchange-one-calcination molecular sieve dry powder with water, addition of second precipitant to cause second precipitation of rare earth ions in the one-exchange-one-calcination molecular sieve dry powder, and then sequential second ammonium sulfate exchange, second water washing, and second calcination to obtain low-sulfate rare earth modified Y-type molecular sieve; wherein the second calcination conditions comprise 100% water vapor atmosphere, temperature of 400-700℃, and time of 0.1-10h; (2) catalyst shaping: mixing of water, low-sulfate rare earth modified Y-type molecular sieve, ZSM-5 molecular sieve, clay, and binder to obtain a mixture, and then homogenization, spray drying, and third calcination to obtain Na-containing catalyst; (3) sodium reduction modification with phosphorus-containing substance: mixing of water with Na-containing catalyst particles, slurry preparation, addition of phosphorus-containing substance for sodium reduction modification of the Na-containing catalyst, filtration, water washing, and drying to obtain propylene-rich catalytic cracking catalyst.

2. The production method according to claim 1, characterized by, In step one, the rare earth ion exchange conditions comprise temperature of 25-180℃, pH of 2.8-6.5, and time of 0.3-3.5h. The rare earth ion exchange process comprises mixing of the Na-type molecular sieve with water, and then addition of soluble rare earth salt for the rare earth ion exchange.

3. The preparation method according to claim 2, characterized in that, The rare earth ion exchange conditions comprise temperature of 50-80℃, pH of 3.5-4.5, and time of 0.5-1.5h.

4. The production method according to claim 2 or 3, characterized by, In step one, the weight ratio of the Na-type molecular sieve to water is 1:1.5-30.

5. The preparation method according to claim 4, characterized in that, In step one, the weight ratio of the Na-type molecular sieve to water is 1:2-5.

6. The production method according to claim 2 or 3, characterized by, The content of the soluble rare earth salt in terms of oxide in the Na-type molecular sieve in terms of dry basis is 1-20wt%.

7. The preparation method according to claim 6, characterized in that, The content of the soluble rare earth salt in terms of oxide in the Na-type molecular sieve in terms of dry basis is 6-16wt%.

8. The production method according to claim 2 or 3, characterized by, The soluble rare earth salt is selected from one or a combination of several of soluble nitrate and chloride of lanthanum, cerium, and yttrium.

9. The preparation method according to claim 2, characterized in that, The Si / Al ratio of the Na-type molecular sieve is 2-100.

10. The method of claim 9, wherein, The Si / Al ratio of the Na-type molecular sieve is 2-50.

11. The method of any one of claims 2, 9-10, wherein, The Na-type molecular sieve is selected from at least one of NaY molecular sieve, NaHY molecular sieve, NaUSY molecular sieve, NaREHY molecular sieve, NaREUSY molecular sieve, Naβ molecular sieve, NaHβ molecular sieve, NaREHβ molecular sieve, NaX molecular sieve, NaREX molecular sieve, and NaHX molecular sieve.

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

13. The method of claim 1, wherein, The amount of the first precipitant in step two is sufficient for the first precipitation of 1-4 wt% of rare earth ions in the Na-type molecular sieve.

14. The method of claim 13, wherein, The amount of the first precipitant is sufficient for the first precipitation of 1.5-2.5 wt% of rare earth ions in the Na-type molecular sieve.

15. The method of any one of claims 1, 13-14, wherein, The first precipitant is at least one selected from the group consisting of ammonium oxalate, ammonium carbonate, ammonium bicarbonate, ammonia, urea and ammonium acetate.

16. The method of claim 15, wherein, The first precipitant is at least one selected from the group consisting of ammonium oxalate, ammonium carbonate, ammonium bicarbonate and ammonia.

17. The method of making according to any one of claims 1, 13-14, wherein, The first precipitation is carried out at a temperature of 25-180 ℃ for 0.1-5 h.

18. The method of claim 17, wherein, The first precipitation is carried out at a temperature of 50-80 ℃ for 0.1-2 h.

19. The method of claim 1, wherein, In step three, the first ammonium sulfate exchange process comprises exchanging the filtered product with a first ammonium sulfate aqueous solution.

20. The method of claim 19, wherein, The weight ratio of the first ammonium sulfate aqueous solution to the Na-type molecular sieve is 5-50:100 in terms of ammonium sulfate.

21. The method of claim 20, wherein, The weight ratio of the first ammonium sulfate aqueous solution to the Na-type molecular sieve is 10-25:100 in terms of ammonium sulfate.

22. The method of any one of claims 19-21, wherein, The concentration of ammonium sulfate in the first ammonium sulfate aqueous solution is 20-400 g / L.

23. The method of claim 22, wherein, The concentration of ammonium sulfate in the first ammonium sulfate aqueous solution is 120-250 g / L.

24. The method of any one of claims 1, 19-21, and 23, wherein, The first ammonium sulfate exchange is carried out at a temperature of 15-150 ℃ for 0.1-5 h.

25. The method of claim 24, wherein, The first ammonium sulfate exchange is carried out at a temperature of 50-80 ℃ for 0.5-2 h.

26. The method of any one of claims 1, 19-21, and 23, wherein, The first ammonium sulfate exchange is tank exchange or belt exchange, or tank exchange and belt exchange are carried out simultaneously.

27. The method of claim 26, wherein, The first ammonium sulfate exchange is tank exchange.

28. The method of making of claim 1 or 19, wherein, In step three, the amount of water used in the first water washing is 1-8 times the weight of the Na-type molecular sieve.

29. The method of claim 28, wherein the method further comprises, The amount of water used in the first water washing is 2-5 times the weight of the Na-type molecular sieve.

30. The method of making according to claim 1 or 19, wherein, In step three, the first calcination is carried out in a 100% water vapor atmosphere at a temperature of 500-650 ℃ for 0.5-3 h.

31. The method of claim 1, wherein, In step four, the amount of the second precipitant is sufficient for the second precipitation of 0.5-3 wt% of rare earth ions in the one-interaction-one-calcination molecular sieve dry powder.

32. The method of claim 31, wherein, In step four, the amount of the second precipitant is sufficient for the second precipitation of 1-2 wt% of rare earth ions in the one-interaction-one-calcination molecular sieve dry powder.

33. The method of any one of claims 1, 31-32, wherein, The second precipitant is at least one selected from the group consisting of ammonium oxalate, ammonium carbonate, ammonium bicarbonate, ammonia, urea and ammonium acetate.

34. The method of claim 33, wherein the method is performed in a single step. The second precipitant is at least one selected from the group consisting of ammonium oxalate, ammonium carbonate, ammonium bicarbonate and ammonia.

35. The method of claim 1, 31-32, wherein, The second precipitation is carried out at a temperature of 15-40 ℃ for 0.1-5 h.

36. The preparation method according to claim 35, characterized in that, The second precipitation is carried out at a temperature of 20-30 ℃ for 0.1-2 h.

37. The method of claim 1, wherein the method is performed in a single step. In step four, the second ammonium sulfate exchange process comprises exchanging the second precipitation product with a second ammonium sulfate aqueous solution.

38. The method of claim 37, wherein the method further comprises, The weight ratio of the second ammonium sulfate aqueous solution to the one-interaction-one-calcination molecular sieve dry powder is 5-50:100 in terms of ammonium sulfate.

39. The method of claim 38, wherein, The weight ratio of the second ammonium sulfate aqueous solution and the dry powder of the first ion-exchange and calcined molecular sieve is 10-25:100, based on ammonium sulfate.

40. The method of any one of claims 37-39, wherein, The concentration of ammonium sulfate in the second ammonium sulfate aqueous solution is 20-400 g / L.

41. The method of claim 40, wherein, The concentration of ammonium sulfate in the second ammonium sulfate aqueous solution is 120-250 g / L.

42. The method of making according to any one of claims 1, 37-39, wherein, The second ammonium sulfate exchange is performed at a temperature of 20-85℃ for 0.1-5 h.

43. The method of claim 42, wherein the method is performed in a single step. The second ammonium sulfate exchange is performed at a temperature of 50-80℃ for 0.1-2 h.

44. The method of claim 1, 37-39, wherein, The second ammonium sulfate exchange is performed by tank exchange or belt exchange, or by tank exchange and belt exchange simultaneously.

45. The method of claim 44, wherein the method is carried out at a temperature of about 20°C to about 30°C. The second ammonium sulfate exchange is performed by tank exchange.

46. The method of claim 1, wherein, The amount of water used in the second water washing is 1-8 times the weight of the dry powder of the first ion-exchange and calcined molecular sieve.

47. The method of claim 46, wherein the method is carried out at a temperature of about 20°C to about 30°C. The amount of water used in the second water washing is 2-5 times the weight of the dry powder of the first ion-exchange and calcined molecular sieve.

48. The method of claim 1, wherein, The second calcination is performed in a 100% steam atmosphere at a temperature of 550-680℃ for 0.5-5 h.

49. The method of claim 1, wherein, The low-sulfate rare earth modified Y-type molecular sieve has SO4 2- a content of ≤1.0 wt%.

50. The method of claim 49, wherein, The low-sulfate rare earth modified Y-type molecular sieve has SO4 2- a content of ≤0.5 wt%.

51. The method of claim 50, wherein, The low-sulfate rare earth modified Y-type molecular sieve has a SO4 2- content of 0.01-0.45 wt%.

52. The method of claim 1, wherein, Step (2) includes catalyst shaping. The Na-containing catalyst is prepared by mixing water, 28-42 parts of low-sulfate rare earth modified Y-type molecular sieve, 2-15 parts of ZSM-5 molecular sieve, 30-65 parts of clay, and 6.5-30 parts of binder, based on 100 parts of the dry mass of the Na-containing catalyst, to form a slurry with a solid content of 25-50 wt%, followed by homogenization, spray shaping, and third calcination.

53. The method of claim 52, wherein, The Na-containing catalyst is prepared by mixing water, 28-38 parts of low-sulfate rare earth modified Y-type molecular sieve, 3-8 parts of ZSM-5 molecular sieve, 35-50 parts of clay, and 7-27 parts of binder, based on 100 parts of the dry mass of the Na-containing catalyst, to form a slurry with a solid content of 35-45 wt%, followed by homogenization, spray shaping, and third calcination.

54. The method of any one of claims 1, 52-53, wherein, The ZSM-5 molecular sieve includes at least one of HZSM-5 and phosphorus-modified ZSM-5.

55. The method of claim 1, 52-53, wherein, The clay includes at least one of kaolin, halloysite, porous stone, diatomite, and water bubble stone.

56. The method of claim 1, 52-53, wherein, The binder includes at least one of aluminum sol, acidified pseudo-boehmite, acidic silicon sol, and phosphorus-aluminum sol.

57. The method of claim 1, 52-53, wherein, The third calcination is performed in an air atmosphere at a temperature of 420-480℃ for 20-50 min.

58. The method of claim 1, wherein, In step (3), 1-3 wt% of the phosphorus-containing substance, based on P2O5, is added to the total dry mass of the Na-containing catalyst to modify the Na-containing catalyst.

59. The method of claim 58, wherein, In step (3), 1.3-2.5 wt% of the phosphorus-containing substance, based on P2O5, is added to the total dry mass of the Na-containing catalyst to modify the Na-containing catalyst.

60. The method of any one of claims 1, 58-59, wherein, In step (3), the water washing is performed at a temperature of 20-100℃ for 0.1-0.3 h.

61. The method of manufacturing according to claim 1 or 58, wherein, The phosphorus-containing substance includes at least one of phosphoric acid, ammonium phosphate, diammonium hydrogen phosphate, and ammonium dihydrogen phosphate.

62. A propylene maximizing catalytic cracking catalyst characterized by, The propylene-rich catalytic cracking catalyst is prepared by the method of any one of claims 1-61.

63. The propylene maximizing catalytic cracking catalyst according to claim 62, wherein, comprises 28-42 wt% of a low-sulfate rare earth modified Y-type molecular sieve, 2-15 wt% of a ZSM-5 molecular sieve, 6.5-30 wt% of a binder, 30-65 wt% of a clay, and 1-3 wt% of a phosphorus-containing compound calculated as P2O5, based on the total weight of the multi-propylene-producing catalytic cracking catalyst being 100%.

64. Use of the multi-propylene-producing catalytic cracking catalyst of claim 62 or 63 in the production of propylene from heavy oil catalytic cracking.

Images