Rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction and preparation method thereof

Abstract

The invention discloses a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction and a preparation method thereof, belonging to the technical field of catalysts. An organic acid and an external silicon source are introduced into a secondary ammonium exchange system, wherein the introduced organic acid can effectively remove non-framework aluminum species generated on the surface of the Y-type molecular sieve during a primary roasting process, and can catalyze the external silicon source to hydrolyze on the surface of the Y-type molecular sieve to generate active silicon oxide species; before the secondary roasting, the Y-type molecular sieve is impregnated with a framework dealuminizing agent, and during the secondary roasting process, the solid acidic oxide contained in the framework dealuminizing agent can react with the framework aluminum species of the Y-type molecular sieve, remove part of the framework aluminum species of the Y-type molecular sieve and generate corresponding framework cavities, and the active silicon oxide on the surface of the Y-type molecular sieve can be timely filled into the framework cavities through solid phase migration, thereby significantly improving the framework silicon-to-aluminum ratio of the Y-type molecular sieve, and the Y-type molecular sieve with good catalytic cracking reaction performance can be obtained without introducing rare earth elements.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and in particular relates to a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction and a preparation method thereof. Background Art

[0002] Catalytic cracking (FCC) is the most important means of lightening heavy oil in the oil refining industry, and is also the secondary processing process of crude oil with the largest amount of catalyst usage. With the increase in the heaviness and inferiority of crude oil and the market demand for light oil products, refineries have put forward higher requirements on the quality of catalytic cracking catalysts in order to improve the ability of catalytic cracking deep processing of heavy crude oil. Y-type molecular sieve has suitable acidity, extremely high specific surface area and good thermal stability. It is the main active component of industrial FCC catalyst. The cracking activity and selectivity of molecular sieve directly affect the product distribution and economic benefits of catalytic cracking unit.

[0003] Y-type molecular sieve is the main active component of FCC catalyst at present, and it plays a decisive role in the reaction performance of FCC catalyst. Since FCC catalyst has to undergo repeated high-temperature hydrothermal regeneration process in FCC reaction device, the Y-type molecular sieve contained in FCC catalyst is required to have excellent hydrothermal stability, so as to avoid the rapid deactivation of FCC catalyst in the device. At present, water vapor super stabilization is the most commonly used method in industry to improve the hydrothermal stability of Y-type molecular sieve. The so-called water vapor super stabilization is to calcine the Y-type molecular sieve under water vapor conditions at high temperature (usually 600 o C), remove some of the framework aluminum species in the Y-type molecular sieve structure, increase the framework silicon-aluminum ratio of the Y-type molecular sieve and shrink the molecular sieve unit cell, thereby improving the hydrothermal stability of the Y-type molecular sieve and obtaining an ultra-stable Y-type molecular sieve (USY). In order to further improve the hydrothermal stability of the USY molecular sieve, it is usually necessary to introduce a certain amount of rare earth elements (Re) during the water vapor ultra-stabilization process of the Y-type molecular sieve, thereby obtaining a rare earth-modified ultra-stable Y-type molecular sieve (REUSY molecular sieve).

[0004] However, the current price of rare earth raw materials is relatively high, and the use of rare earth modification will inevitably significantly increase the current production cost of molecular sieves; on the other hand, the use of rare earth elements for modification will also increase the coke yield of molecular sieves. The above problems have become bottlenecks that restrict the current molecular sieve and FCC catalyst manufacturers from reducing costs and increasing efficiency, which makes the development of rare earth-free, high cracking performance ultra-stable Y-type molecular sieves an urgent problem to be solved. The technology of rare earth-free modified element molecular sieves is currently only reported by Grace Davison in the United States (US3293192A). Based on its unique non-rare earth element modification activity and stability improvement technology, the company's researchers have developed a new type of rare earth-free or low rare earth content high silicon ratio selective molecular sieve (Z-21 and Z-22), and on this basis, a series of rare earth-free or low rare earth FCC catalysts have been developed. However, compared with conventional rare earth modified ultra-stable Y-type molecular sieves, the use of high silicon-aluminum ratio selective molecular sieves has the following problems: (1) The production cost of selective molecular sieves is relatively high, especially the selective molecular sieves with high silicon-aluminum ratios. This means that although they do not contain rare earth modified elements, they have no obvious cost advantage over conventional rare earth modified ultra-stable Y-type molecular sieves. (2) The surface acid density of high silicon-aluminum ratio selective molecular sieves is low, and the cracking activity is usually not high. This means that the FCC catalyst developed based on them can only process light crude oil with better properties, and cannot be used for heavy oil catalytic cracking reactions. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction and a preparation method thereof. Compared with the rare earth modified Y-type molecular sieve, the rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction provided by the present invention has the characteristics of strong heavy oil conversion ability and high light oil yield; and the preparation process is simple, the cost is low, and it is convenient for large-scale industrial production.

[0006] To achieve the above object, the present invention provides a method for preparing a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction, comprising the following steps:

[0007] The NaY molecular sieve, ammonium salt and water are mixed, slurried, stirred continuously at a temperature of 60-95° C. for 1-4 hours, filtered, washed and dried, and then subjected to hydrothermal ultra-stabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain a pretreated NaY molecular sieve;

[0008] The pretreated NaY molecular sieve, ammonium salt, silicon source, organic acid and water are mixed, slurried, stirred and reacted at 60-95° C. for 1-4 hours, and then filtered and washed to obtain a molecular sieve filter cake;

[0009] The molecular sieve filter cake is mixed with a skeleton dealuminizing agent, slurried, dried, and then subjected to hydrothermal ultra-stabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain the rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction.

[0010] The ammonium salt is selected from one of ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium hydrogen sulfate, ammonium phosphate, ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, ammonium oxalate, ammonium citrate and ammonium acetate.

[0011] When pretreating NaY molecular sieve, the mass ratio of NaY molecular sieve, ammonium salt and water is 1: (0.1~0.3): (4~8).

[0012] The silicon source is selected from one of sodium silicate, potassium silicate, methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and butyl orthosilicate.

[0013] The organic acid is selected from one of formic acid, acetic acid, oxalic acid, citric acid, gallic acid, ascorbic acid and tartaric acid.

[0014] When preparing the molecular sieve filter cake, the mass ratio of the pretreated NaY molecular sieve, ammonium salt, silicon source, organic acid and water is 1: (0.1-0.3): (0.005-0.05): (0.01-0.05): (4-8), and the mass of the silicon source is calculated according to the mass of SiO2 in the silicon source.

[0015] The mass ratio of the molecular sieve filter cake to the skeleton dealuminizing agent is 1: (0.0001-0.0005), and the mass of the skeleton dealuminizing agent is calculated according to the mass of the oxides contained therein.

[0016] Preferably, the mass ratio of the molecular sieve filter cake to the skeleton dealuminizing agent is 1:(0.0001-0.0003), and the mass of the skeleton dealuminizing agent is calculated based on the mass of the oxides contained therein.

[0017] The skeleton dealuminizing agent is selected from one of vanadic acid, ammonium metavanadate and vanadium pentoxide, preferably vanadium pentoxide.

[0018] The present invention also provides a rare earth-free Y-type molecular sieve prepared according to the above method and used in heavy oil catalytic cracking reaction.

[0019] The rare earth-free Y-type molecular sieve prepared by the method of the present invention is a rare earth-free, high cracking reaction performance and ultra-stable Y-type molecular sieve, which can be used for heavy oil catalytic cracking reaction.

[0020] Compared with the prior art, the present invention has the following advantages and technical effects:

[0021] The FCC reaction system is a high temperature, water vapor atmosphere, where the reaction temperature is usually higher than 500°C, the FCC catalyst regeneration temperature is as high as 700°C, and there are a large number of water vapor molecules in the reaction system. In such a high temperature, water vapor atmosphere, the high temperature water vapor molecules will cause serious structural damage to the Y-type molecular sieve contained in the FCC catalyst, thereby seriously affecting the catalytic cracking reaction performance of the Y-type molecular sieve. Therefore, this requires that the Y-type molecular sieve contained in the FCC catalyst must have excellent hydrothermal stability. In view of the above problems, the present invention prepares a rare earth-free ultra-stable Y-type molecular sieve for heavy oil catalytic cracking reaction based on "two cross-coupling and two roasting", introduces an organic acid and an external silicon source into the secondary ammonium exchange system, and the introduced organic acid can effectively remove the non-framework aluminum species generated on the surface of the Y-type molecular sieve during the first roasting process, and can catalyze (acid catalysis) the hydrolysis of the external silicon source on the surface of the Y-type molecular sieve to generate active silicon oxide species; at the same time, before the second roasting (hydrothermal ultra-stabilization), the Y-type molecular sieve is impregnated with a framework dealuminant, so that in the subsequent second roasting process, the solid acidic oxide contained in the framework dealuminant can react with the framework aluminum species of the Y-type molecular sieve, thereby removing part of the framework aluminum species of the Y-type molecular sieve and generating corresponding framework cavities, and the active silicon oxide present on the surface of the Y-type molecular sieve can be timely filled into the above-mentioned framework cavities through solid phase migration, thereby significantly improving the framework silicon-to-aluminum ratio of the Y-type molecular sieve. Therefore, based on the above-mentioned mechanism of action, the method of the present invention can obtain an ultra-stable Y-type molecular sieve with a high framework silicon-aluminum ratio, which will greatly improve the hydrothermal stability of the current ultra-stable Y-type molecular sieve, and then improve its catalytic cracking reaction performance. A Y-type molecular sieve with good catalytic cracking reaction performance can be prepared without introducing rare earth elements.

[0022] Compared with conventional rare earth modified ultra-stable Y-type molecular sieves, the rare earth-free ultra-stable Y-type molecular sieve for heavy oil catalytic cracking reaction prepared by the present invention has the characteristics of strong heavy oil conversion ability, high light oil yield, and good resistance to heavy metal pollution. In addition, the preparation process is simple, the cost is low, and it is convenient for large-scale industrial production. DETAILED DESCRIPTION

[0023] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0024] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0025] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0026] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0027] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0028] Heavy oil is the extracted oil obtained by solvent extraction of tar, visbreaking distillate oil, vacuum residue oil in the petroleum refining industry, or atmospheric heavy oil and vacuum residue oil that have been hydrogenated, or even heavy oil components such as atmospheric heavy oil and vacuum residue oil themselves.

[0029] "Hydrothermal ultra-stabilization treatment" is a method to enhance the stability of molecular sieves through high temperature and water vapor treatment. This method is usually used to prepare ultra-stable Y-type molecular sieves, and its thermal stability and catalytic performance are improved through modification steps such as ion exchange, hydrothermal roasting, chemical aluminum extraction and silicon supplementation.

[0030] In the embodiments of the present invention, the raw materials and specifications, the skeleton silicon-aluminum ratio and the crystallinity analysis method and the catalyst cracking reaction performance evaluation method are as follows:

[0031] (1) Raw materials and specifications

[0032] NaY molecular sieve, aluminum sol (Al2O3 content 19.40 wt%), kaolin and mixed rare earth solution (Re2O3 content: 301.25 g / L, La / Ce molar ratio = 2), qualified industrial products.

[0033] Ammonium chloride, citric acid, potassium silicate, gallic acid, vanadic acid, ammonium metavanadate, ammonium phosphate, ascorbic acid, ammonium oxalate, ammonium citrate, tartaric acid, ammonium monohydrogen phosphate, propyl orthosilicate, formic acid, ethyl orthosilicate, and vanadium pentoxide, analytically pure reagents, were purchased from Sinopharm Group.

[0034] (2) Analysis of framework silicon-aluminum ratio and crystallinity

[0035] The crystallinity and framework silicon-aluminum ratio parameters of the molecular sieve were analyzed on a D / max-2200 PC X-ray diffractometer produced by Rigaku Corporation of Japan.

[0036] (3) Catalyst cracking reaction performance evaluation

[0037] The cracking activity of the ultrastable molecular sieve samples was evaluated on a CSA-B catalytic cracking evaluation unit at a reaction temperature of 460°C. The molecular sieve pellet samples were pre-treated at 800°C and 100% steam for 6 hours.

[0038] The heavy oil catalytic cracking reaction performance of the catalyst samples was evaluated on an ACE (Advanced cracking evaluation, R + MultiMode, origin: the United States) device. The reaction temperature of the device was 530°C, the catalyst / feedstock mass ratio was 5, the catalyst was pre-treated at 800°C and 100% steam for 17 hours, and the properties of the feedstock are shown in Table 1.

[0039] Table 1 Raw oil properties

[0040]

[0041] It should be pointed out that the matters not described in detail in the present invention are all conventional operating means in the field and are not the focus of the present invention. For example, specific methods such as filtering, washing, drying, and beating are all completed by conventional methods.

[0042] The technical solution of the present invention is further illustrated by the following embodiments.

[0043] Example 1

[0044] This embodiment provides a method for preparing a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction:

[0045] (1) 300 g of NaY molecular sieve (dry basis), 30 g of ammonium chloride, and 1200 g of deionized water were mixed and slurried, stirred continuously at 95° C. for 1 hour, filtered, washed, and dried, and then subjected to hydrothermal ultrastabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain a pretreated NaY molecular sieve;

[0046] (2) 200 g of pretreated NaY molecular sieve, 20 g of ammonium chloride, 6.94 g of ethyl orthosilicate, 2 g of citric acid and 800 g of deionized water were mixed and slurried, and stirred at 65° C. for 4 hours, and then filtered and washed to obtain a molecular sieve filter cake;

[0047] (3) 200 g of molecular sieve filter cake and 0.02 g of vanadium pentoxide were fully mixed and slurried, dried, and then subjected to hydrothermal ultra-stabilization treatment at 600°C and 100% water vapor for 2 hours to obtain rare earth-free Y-type molecular sieve C1 for heavy oil catalytic cracking reaction.

[0048] Example 2

[0049] This embodiment provides a method for preparing a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction:

[0050] (1) 300 g of NaY molecular sieve (dry basis), 60 g of ammonium chloride, and 1800 g of deionized water were mixed and slurried, stirred at 75° C. for 2 hours, filtered, washed, and dried, and then subjected to hydrothermal ultrastabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain a pretreated NaY molecular sieve;

[0051] (2) 200 g of pretreated NaY molecular sieve, 40 g of ammonium chloride, 20.8 g of ethyl orthosilicate, 6 g of citric acid and 1200 g of deionized water were mixed and slurried, and stirred at 80° C. for 2 hours, and then filtered and washed to obtain a molecular sieve filter cake;

[0052] (3) 200 g of molecular sieve filter cake was fully mixed with 0.06 g of vanadium pentoxide, slurried, dried, and subjected to hydrothermal ultra-stabilization treatment at 600°C and 100% water vapor for 2 hours to obtain rare earth-free Y-type molecular sieve C2 for heavy oil catalytic cracking reaction.

[0053] Example 3

[0054] This embodiment provides a method for preparing a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction:

[0055] (1) 300 g of NaY molecular sieve (dry basis), 90 g of ammonium chloride, and 2400 g of deionized water were mixed and slurried, stirred continuously at 65° C. for 4 hours, filtered, washed, and dried, and then subjected to hydrothermal ultrastabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain a pretreated NaY molecular sieve;

[0056] (2) 200 g of pretreated NaY molecular sieve, 60 g of ammonium chloride, 34.7 g of ethyl orthosilicate, 10 g of citric acid and 1600 g of deionized water were mixed and slurried, and stirred at 95° C. for 1 hour, and then filtered and washed to obtain a molecular sieve filter cake;

[0057] (3) 200 g of molecular sieve filter cake and 0.1 g of vanadium pentoxide were fully mixed and slurried, dried, and then subjected to hydrothermal ultra-stabilization treatment at 600°C and 100% water vapor for 2 hours to obtain rare earth-free Y-type molecular sieve C3 for heavy oil catalytic cracking reaction.

[0058] Example 4

[0059] This embodiment provides a method for preparing a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction:

[0060] (1) 300 g of NaY molecular sieve (dry basis), 60 g of ammonium sulfate, and 1600 g of deionized water were mixed and slurried, stirred continuously at 75° C. for 2 hours, filtered, washed, and dried, and then subjected to hydrothermal ultrastabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain a pretreated NaY molecular sieve;

[0061] (2) 200 g of pretreated NaY molecular sieve, 40 g of ammonium sulfate, 5 g of potassium silicate, 6 g of gallic acid and 1200 g of deionized water were mixed and slurried, and stirred at 75°C for 2 hours, and then filtered and washed to obtain a molecular sieve filter cake;

[0062] (3) 200 g of molecular sieve filter cake was fully mixed with 0.06 g of vanadic acid, slurried, dried, and subjected to hydrothermal ultra-stabilization treatment at 600°C and 100% water vapor for 2 hours to obtain rare earth-free Y-type molecular sieve C4 for heavy oil catalytic cracking reaction.

[0063] Example 5

[0064] This embodiment provides a method for preparing a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction:

[0065] The preparation method is the same as that of Example 2, except that vanadic acid is replaced with ammonium metavanadate of equal mass, and the obtained rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction is denoted as C5.

[0066] Example 6

[0067] This embodiment provides a method for preparing a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction:

[0068] (1) 300 g of NaY molecular sieve (dry basis), 60 g of ammonium phosphate and 1600 g of deionized water were mixed and slurried, stirred at 80° C. for 2 hours, filtered, washed and dried, and then subjected to hydrothermal ultra-stabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain a pretreated NaY molecular sieve;

[0069] (2) 200 g of pretreated NaY molecular sieve, 40 g of ammonium phosphate, 5 g of butyl orthosilicate, 6 g of ascorbic acid and 1200 g of deionized water were mixed and slurried, and stirred at 80° C. for 2 hours, and then filtered and washed to obtain a molecular sieve filter cake;

[0070] (3) 200 g of molecular sieve filter cake and 0.06 g of vanadium pentoxide were fully mixed and slurried, dried, and then subjected to hydrothermal ultra-stabilization treatment at 600°C and 100% water vapor for 2 hours to obtain rare earth-free Y-type molecular sieve C6 for heavy oil catalytic cracking reaction.

[0071] Example 7

[0072] This embodiment provides a method for preparing a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction:

[0073] (1) 300 g of NaY molecular sieve (dry basis), 60 g of ammonium oxalate and 1600 g of deionized water were mixed and slurried, stirred at 80° C. for 2 hours, filtered, washed and dried, and then subjected to hydrothermal ultra-stabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain a pretreated NaY molecular sieve;

[0074] (2) 200 g of pretreated NaY molecular sieve, 40 g of ammonium oxalate, 5 g of sodium silicate, 6 g of ascorbic acid and 1200 g of deionized water were mixed and slurried, and stirred at 80° C. for 2 hours, and then filtered and washed to obtain a molecular sieve filter cake;

[0075] (3) 200 g of molecular sieve filter cake and 0.06 g of vanadium pentoxide were fully mixed and slurried, dried, and then subjected to hydrothermal ultra-stabilization treatment at 600°C and 100% water vapor for 2 hours to obtain rare earth-free Y-type molecular sieve C7 for heavy oil catalytic cracking reaction.

[0076] Example 8

[0077] This embodiment provides a method for preparing a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction:

[0078] (1) 300 g of NaY molecular sieve (dry basis), 60 g of ammonium citrate and 1600 g of deionized water were mixed and slurried, stirred at 80° C. for 2 hours, filtered, washed and dried, and then subjected to hydrothermal ultra-stabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain a pretreated NaY molecular sieve;

[0079] (2) 200 g of pretreated NaY molecular sieve, 40 g of ammonium citrate, 5 g of ethyl orthosilicate, 6 g of tartaric acid and 1200 g of deionized water were mixed and slurried, and stirred at 80° C. for 2 hours, and then filtered and washed to obtain a molecular sieve filter cake;

[0080] (3) 200 g of molecular sieve filter cake and 0.06 g of vanadium pentoxide were fully mixed and slurried, dried, and then subjected to hydrothermal ultra-stabilization treatment at 600°C and 100% water vapor for 2 hours to obtain rare earth-free Y-type molecular sieve C8 for heavy oil catalytic cracking reaction.

[0081] Example 9

[0082] This embodiment provides a method for preparing a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction:

[0083] (1) 300 g of NaY molecular sieve (dry basis), 60 g of ammonium monohydrogen phosphate, and 1600 g of deionized water were mixed and slurried, stirred at 80° C. for 2 hours, filtered, washed, and dried, and then subjected to hydrothermal ultrastabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain a pretreated NaY molecular sieve;

[0084] (2) 200 g of pretreated NaY molecular sieve, 40 g of ammonium monohydrogen phosphate, 5 g of propyl orthosilicate, 6 g of formic acid and 1200 g of deionized water were mixed and slurried, and stirred at 80° C. for 2 hours, and then filtered and washed to obtain a molecular sieve filter cake;

[0085] (3) 200 g of molecular sieve filter cake and 0.04 g of vanadium pentoxide were fully mixed and slurried, dried, and then subjected to hydrothermal ultra-stabilization treatment at 600°C and 100% water vapor for 2 hours to obtain rare earth-free Y-type molecular sieve C9 for heavy oil catalytic cracking reaction.

[0086] Preparation of the rare earth-free ultra-stable Y-type molecular sieve FCC catalyst for heavy oil catalytic cracking reaction of the present invention:

[0087] According to the solid dry basis mass ratio of molecular sieve:aluminum sol:kaolin =35:12:53, 105 grams of rare earth-free Y-type molecular sieve C2 for heavy oil catalytic cracking reaction, 185.5 grams of aluminum sol, 159 grams of kaolin and 550.5 grams of deionized water were mixed, slurried, spray-dried and formed, and then calcined and solidified (450°C, 0.5 hour), washed and dried to obtain FCC catalyst C1.

[0088] Comparative Example 1

[0089] Preparation of conventional rare earth modified ultra-stable Y-type molecular sieve:

[0090] (1) 300 g of NaY molecular sieve (dry basis), 30 g of ammonium chloride, and 1200 g of deionized water were mixed and slurried, stirred continuously at 95° C. for 1 hour, filtered, washed, and dried, and then subjected to hydrothermal ultrastabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain a pretreated NaY molecular sieve;

[0091] (2) 200 g of pretreated NaY molecular sieve, 20 g of ammonium chloride and 800 g of deionized water were mixed and slurried, and the mixture was stirred and reacted at 65° C. for 4 hours, and then filtered and washed to obtain a molecular sieve filter cake;

[0092] (3) 200 g of molecular sieve filter cake was fully mixed and slurried with 6.64 ml of mixed rare earth solution, and after drying, hydrothermal ultra-stabilization treatment was performed at 600°C and 100% water vapor for 2 hours to obtain conventional rare earth modified ultra-stable Y-type molecular sieve D1.

[0093] Comparative Example 2

[0094] Preparation of conventional rare earth modified ultra-stable Y-type molecular sieve:

[0095] (1) 300 g of NaY molecular sieve (dry basis), 60 g of ammonium chloride, and 1800 g of deionized water were mixed and slurried, stirred at 75° C. for 2 hours, filtered, washed, and dried, and then subjected to hydrothermal ultrastabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain a pretreated NaY molecular sieve;

[0096] (2) 200 g of pretreated NaY molecular sieve, 40 g of ammonium chloride and 1200 g of deionized water were mixed and slurried, and stirred and reacted at 80° C. for 2 hours, and then filtered and washed to obtain a molecular sieve filter cake;

[0097] (3) 200 g of molecular sieve filter cake was fully mixed and slurried with 9.96 ml of mixed rare earth solution, and after drying, hydrothermal ultra-stabilization treatment was performed at 600°C and 100% water vapor for 2 hours to obtain conventional rare earth modified ultra-stable Y-type molecular sieve D2.

[0098] Comparative Example 3

[0099] Preparation of conventional rare earth modified ultra-stable Y-type molecular sieve:

[0100] (1) 300 g of NaY molecular sieve (dry basis), 90 g of ammonium chloride, and 2400 g of deionized water were mixed and slurried, stirred continuously at 65° C. for 4 hours, filtered, washed, and dried, and then subjected to hydrothermal ultrastabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain a pretreated NaY molecular sieve;

[0101] (2) 200 g of pretreated NaY molecular sieve, 60 g of ammonium chloride and 1600 g of deionized water were mixed and slurried, and the mixture was stirred and reacted at 95° C. for 1 hour, and then filtered and washed to obtain a molecular sieve filter cake;

[0102] (3) 200 g of molecular sieve filter cake was fully mixed and slurried with 13.27 ml of mixed rare earth solution, and after drying, hydrothermal ultra-stabilization treatment was performed at 600°C and 100% water vapor for 2 hours to obtain conventional rare earth modified ultra-stable Y-type molecular sieve D3.

[0103] Preparation of ultra-stable Y-type molecular sieve FCC catalyst modified with conventional rare earth:

[0104] According to the solid dry basis mass ratio of molecular sieve:aluminum sol:kaolin =35:12:53, 105 grams of conventional rare earth modified ultra-stable Y-type molecular sieve D2, 185.5 grams of aluminum sol, 159 grams of kaolin and 550.5 grams of deionized water were mixed, slurried, spray-dried and formed, and then calcined and cured (450°C, 0.5 hour), washed and dried to obtain FCC catalyst D1.

[0105] The physical and chemical properties and cracking activities of the Y-type molecular sieves prepared in the above examples and comparative examples are shown in Table 2.

[0106] Table 2 Physical and chemical properties and cracking activity of different ultra-stable Y-type molecular sieves

[0107]

[0108] It can be seen from Table 2 that compared with conventional rare earth modified ultra-stable Y-type molecular sieve samples, the rare earth-free ultra-stable Y-type molecular sieve prepared by the method of the present invention for heavy oil catalytic cracking reaction has a significantly higher framework silicon-aluminum ratio and crystallinity, which makes its cracking activity significantly higher than that of conventional rare earth modified ultra-stable Y-type molecular sieve.

[0109] The heavy oil catalytic cracking reaction performance of the prepared FCC catalyst samples is shown in Table 3.

[0110] Table 3 FCC catalyst heavy oil catalytic cracking reaction performance

[0111]

[0112] It can be seen from Table 3 that under the condition of the same molecular sieve content, compared with the catalyst prepared by using the conventional rare earth modified ultra-stable Y-type molecular sieve, the rare earth-free ultra-stable Y-type molecular sieve catalyst for heavy oil catalytic cracking reaction prepared by the method of the present invention not only shows a stronger heavy oil conversion ability, but also the liquid product (total liquid yield) and gasoline yield are significantly higher than the former. It can be said that it has excellent heavy oil catalytic cracking reaction performance.

[0113] In order to investigate the ability of the catalyst to resist heavy metal pollution, FCC catalyst C1 and FCC catalyst D1 were impregnated in 4000 ppm V, 7000 ppm Ni, and 8000 ppm Fe, respectively, by equal volume impregnation method. The FCC catalyst contaminated with V, Ni and Fe was treated at 800 °C and 100% steam for 17 hours. The heavy oil catalytic cracking reaction performance is shown in Table 4.

[0114] Table 4 Heavy oil catalytic cracking performance of heavy metal contaminated FCC catalyst

[0115]

[0116] It can be seen from Table 4 that, compared with the conventional rare earth modified ultra-stable Y-type molecular sieve FCC catalyst D1, the rare earth-free ultra-stable Y-type molecular sieve FCC catalyst C1 for heavy oil catalytic cracking reaction prepared by the method of the present invention shows significantly stronger heavy oil conversion ability, higher light oil yield (total liquid yield), and has more excellent resistance to heavy metal pollution.

[0117] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing a rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction, characterized in that: The following steps are involved: The NaY molecular sieve, ammonium salt and water are mixed, slurried, continuously stirred at a temperature of 60-95° C. for 1-4 hours, filtered, washed and dried, and then subjected to hydrothermal ultra-stabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain a pretreated NaY molecular sieve. When the NaY molecular sieve is pretreated, the mass ratio of the NaY molecular sieve, the ammonium salt and the water is 1:(0.1-0.3):(4-8); The pretreated NaY molecular sieve, ammonium salt, silicon source, organic acid and water are mixed, slurried, stirred and reacted at 60-95° C. for 1-4 hours, and then filtered and washed to obtain a molecular sieve filter cake; The molecular sieve filter cake is mixed with a skeleton dealuminant, slurried, dried, and then subjected to hydrothermal ultra-stabilization treatment at 600° C. and 100% water vapor for 2 hours to obtain the rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction; When preparing the molecular sieve filter cake, the mass ratio of the pretreated NaY molecular sieve, the ammonium salt, the silicon source, the organic acid and the water is 1: (0.1-0.3): (0.005-0.05): (0.01-0.05): (4-8), and the mass of the silicon source is calculated according to the mass of SiO2 in the silicon source; The mass ratio of the molecular sieve filter cake to the skeleton dealuminizing agent is 1: (0.0001-0.0005), and the mass of the skeleton dealuminizing agent is calculated according to the mass of the oxides contained therein; The skeleton dealuminizing agent is selected from one of vanadic acid, ammonium metavanadate and vanadium pentoxide.

2. The method for preparing the rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction according to claim 1, characterized in that: The ammonium salt is selected from one of ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium hydrogen sulfate, ammonium phosphate, ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, ammonium oxalate, ammonium citrate and ammonium acetate.

3. The method for preparing the rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction according to claim 1, characterized in that: The silicon source is selected from one of sodium silicate, potassium silicate, methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and butyl orthosilicate.

4. The method for preparing the rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction according to claim 1, characterized in that: The organic acid is selected from one of formic acid, acetic acid, oxalic acid, citric acid, gallic acid, ascorbic acid and tartaric acid.

5. The method for preparing rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction according to claim 1, characterized in that: The mass ratio of the molecular sieve filter cake to the skeleton dealuminizing agent is 1: (0.0001-0.0003), and the mass of the skeleton dealuminizing agent is calculated according to the mass of the oxides contained therein.

6. A rare earth-free Y-type molecular sieve for heavy oil catalytic cracking reaction, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 5.

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