Gas-phase ultra-stable mesoporous Y molecular sieve, preparation method thereof and crude oil catalytic cracking catalyst containing gas-phase ultra-stable mesoporous Y molecular sieve

Abstract

The invention provides a gas-phase ultra-stable mesoporous Y molecular sieve, a preparation method thereof and a crude oil catalytic cracking catalyst containing the gas-phase ultra-stable mesoporous Y molecular sieve. The preparation method comprises the following steps: preparing a NaY molecular sieve, and adding a pore-enlarging agent in the process of preparing the NaY molecular sieve to prepare the NaY molecular sieve with the pore-enlarging agent wrapped in the crystal grains in advance; the NaY molecular sieve and SiCl4 are subjected to a gas-phase ultra-stable reaction, a product of the gas-phase ultra-stable reaction is roasted to remove the pore-enlarging agent, and a gas-phase ultra-stable mesoporous Y molecular sieve is obtained; the pore-enlarging agent is a water-soluble cationic polymer; the raw material for preparing the NaY molecular sieve is calculated by SiO2, and the weight ratio of the pore-enlarging agent to the raw material for preparing the NaY molecular sieve is greater than or equal to 0.3. On the basis, a mesoporous structure is efficiently introduced into the gas-phase ultra-stable Y molecular sieve.

Description

Technical Field

[0001] This invention belongs to the field of oil refining catalysts, specifically relating to a gas-phase ultrastable mesoporous Y molecular sieve, its preparation method, and a crude oil catalytic cracking catalyst containing the same. Background Technology

[0002] Ultra-stable Y-type molecular sieves (USY) exhibit good hydrothermal stability and a high ratio of cracking / hydrogen transfer reactions. In actual plant operation, they are characterized by strong acidity, low coke yield, and good activity stability, making them the most widely used active component in catalytic cracking / pyrolysis catalysts.

[0003] Currently, there are two main methods for industrial production of ultrastable Y-type molecular sieves: the hydrothermal ultrastable method and the gas-phase ultrastable method. The advantages and disadvantages of the two production methods are shown in Table 1.

[0004] Table 1

[0005]

[0006] As can be seen from Table 1, gas-phase ultrastable Y-type molecular sieves have many advantages. However, due to the reaction mechanism of gas-phase ultrastable sieves, the dealumination and silicon replenishment processes are relatively balanced, resulting in very few mesopores in the gas-phase ultrastable Y-type molecular sieve products, which have the disadvantage of being non-mesopores.

[0007] Several reports have been published regarding gas-phase ultrastable Y molecular sieves. For example, patent CN114835135A discloses a titanium-containing gas-phase ultrastable mesoporous Y zeolite, its preparation method, and its applications. The preparation method includes the following steps: Step 1, a gas-solid reaction is carried out between microporous NaY zeolite and titanium tetrachloride gas at a temperature of 350–550°C for 10–240 minutes; and Step 2, the NaY zeolite obtained in Step 1 is washed with deionized water, filtered, and dried to obtain titanium-containing gas-phase ultrastable mesoporous Y zeolite. The Y zeolite prepared by this invention has a relatively rich mesoporous structure, suitable acidity, and a controllable titanium-silicon ratio. The catalytic cracking catalyst prepared from the obtained Y zeolite has a good ability to increase the conversion of heavy oil and improve the yield of light oil. For example, patent CN1382525A discloses a method for preparing rare-earth high-silica Y-type zeolite. This method includes drying the rare-earth-containing Y-type zeolite to reduce its water content to below 10 wt%, then introducing silicon tetrachloride gas carried by dry air at a weight ratio of silicon tetrachloride to Y-zeolite of 0.1–0.9:1. The reaction is carried out at a temperature of 150–600°C for 10 minutes to 6 hours. After the reaction, the mixture is purged with dry air for 5 minutes to 2 hours. This gas-phase aluminum extraction and silicon replenishment method overcomes the disadvantages of chemical dealumination and hydrothermal dealumination methods, which result in dealumination voids in the molecular sieve and low retention of molecular sieve crystals.

[0008] However, the existing technologies mentioned above focus on the preparation methods and equipment processes of ultrastable Y-type molecular sieves, and still do not address how to introduce mesopores into gas-phase ultrastable Y-type molecular sieves. Crude oil catalytic cracking is an important direction for the transformation and development of refining and chemical industries. Crude oil has a wide range of fractions, diverse structures, and large differences in molecular bond energies, presenting technical challenges in single-reactor scenarios, such as the difficulty in cracking small-molecule hydrocarbons and the tendency for large-molecule hydrocarbons to coke. This necessitates catalytic active centers with strong acidity, weak hydrogen transfer, and good diffusion performance for large molecules. Mesoporous gas-phase ultrastable Y-type molecular sieves possess these characteristics, making them an ideal active component for crude oil catalytic cracking. Therefore, how to efficiently introduce mesopores into conventional gas-phase ultrastable Y-type molecular sieves to improve the accessibility and diffusion efficiency of active centers is of great significance for developing catalytic materials suitable for crude oil catalytic cracking. Summary of the Invention

[0009] To address the aforementioned technical problems, the present invention aims to provide a gas-phase ultrastable mesoporous Y molecular sieve, its preparation method, and a crude oil catalytic cracking catalyst containing the same. This preparation method can efficiently introduce mesoporous structures into the gas-phase ultrastable Y molecular sieve.

[0010] To achieve the above objectives, the present invention provides a method for preparing a gas-phase ultrastable mesoporous Y molecular sieve, comprising: preparing a NaY molecular sieve; adding a pore-expanding agent during the preparation of the NaY molecular sieve to obtain a NaY molecular sieve in which the pore-expanding agent is pre-coated inside the crystal grains; subjecting the NaY molecular sieve to a gas-phase ultrastable reaction with SiCl4, and calcining the product of the gas-phase ultrastable reaction to remove the pore-expanding agent, thereby obtaining a gas-phase ultrastable mesoporous Y molecular sieve; wherein the pore-expanding agent is a water-soluble cationic polymer; the raw material for preparing the NaY molecular sieve is SiO2, and the weight ratio of the pore-expanding agent to the raw material for preparing the NaY molecular sieve is greater than or equal to 0.3.

[0011] Water-soluble cationic polymers possess abundant cationic charges and are added as pore expanders during the conventional preparation of NaY molecular sieves. The cationic charges can generate strong electrostatic forces with oligomeric silicate species, thus they can be easily encapsulated within the crystals during the crystallization process of NaY molecular sieves. After such NaY molecular sieves undergo a gas-phase ultrastable reaction with SiCl4, the pore expander can be removed by calcination, thereby forming mesoporous channels with a template-like structure in the molecular sieve. This achieves the beneficial effect of efficiently introducing mesoporous structures into gas-phase ultrastable Y molecular sieves and further shrinking the unit cell.

[0012] Furthermore, the pore-expanding agent is polyquaternium-6 and / or polyquaternium-7. Both polyquaternium-6 and polyquaternium-7 have abundant cationic charges that can generate strong electrostatic forces with oligomeric silicate species. Therefore, they are easily encapsulated inside the grains during the crystallization process of zeolite molecular sieves, and form mesoporous channels with template-like structures through the calcination process.

[0013] Furthermore, in the process of preparing NaY molecular sieves, the raw material for preparing NaY molecular sieves is SiO2, and the weight ratio of the pore-expanding agent to the raw material for preparing NaY molecular sieves is 0.3 to 3:1.

[0014] Further, the weight ratio of SiCl4 to NaY molecular sieve is 0.1 to 0.5:1. Preferably, the weight ratio of SiCl4 to NaY molecular sieve is 0.2 to 0.4:1.

[0015] Furthermore, the calcination temperature is 540–590°C, and the processing time is 4–12 hours. In some optional embodiments, the calcination equipment can be a muffle furnace or a converter.

[0016] Furthermore, the water content of the NaY molecular sieve is less than 1.5 wt%, which avoids the violent reaction between free water and SiCl4, causing it to fail. In an optional embodiment, the conventionally prepared NaY molecular sieve can be dried with dry hot air to reduce its water content to less than 1.5 wt% before being contacted with SiCl4 for the gas-phase ultrastable reaction.

[0017] Furthermore, the reaction temperature of the gas-phase ultrastable reaction is 350–500°C, and the reaction time is 0.1–2 h. Preferably, the reaction temperature of the gas-phase ultrastable reaction is 370–450°C; the reaction time is 0.2–1 h; and the reactor is a tube furnace.

[0018] Furthermore, the water content of the product of the gas-phase ultrastable reaction is less than 5 wt%. In an optional embodiment, after the gas-phase ultrastable reaction, the above-mentioned method for preparing the gas-phase ultrastable mesoporous Y molecular sieve further includes the steps of washing (using deionized water at 85-100°C), filtering, and drying the product of the gas-phase ultrastable reaction in sequence, so that the water content of the product of the gas-phase ultrastable reaction is <5 wt%. At the same time, this can also remove reaction byproduct impurities such as NaCl and AlCl3 from the product of the gas-phase ultrastable reaction, so that the sodium oxide content of the gas-phase ultrastable mesoporous Y molecular sieve is <1.8 wt%, achieving the purpose of not affecting the acidity of the molecular sieve.

[0019] Furthermore, the gas-phase ultrastable mesoporous Y molecular sieve has a mesopore volume >0.15 cm³. 3 / g, mesoporous pore volume accounts for more than 30% of the total pore volume of gas-phase ultrastable mesoporous Y molecular sieve, relative crystallinity >85%, cell constant < Sodium oxide content <1.8 wt%.

[0020] In a preferred embodiment, the raw materials for preparing NaY molecular sieves include a silicon source, an alkaline solution, a directing agent, and an aluminum source. NaY molecular sieves are prepared through the following steps: mixing the silicon source and the pore-expanding agent to form a mixed system; adding the alkaline solution, the directing agent, and the aluminum source to the mixed system to form a gel system; crystallizing the gel system at a temperature of 70–120°C for 8–48 hours to form a crystallized system; and sequentially filtering, washing, and drying the crystallized system to obtain NaY molecular sieves. The molar composition of the gel system is (2–5) Na₂O: (0.7–1.3) Al₂O₃: (6–12) SiO₂: (100–250) H₂O: (0.05–0.5) directing agent.

[0021] The silicon source, alkali solution, directing agent, and aluminum source used in the above-mentioned preparation process of NaY molecular sieves are all conventional raw materials used in the preparation of NaY molecular sieves in this field, and are not specifically limited. Preferably, the alkali solution is a sodium hydroxide solution, the molar composition of the directing agent is (12-18)Na2O:(0.7-1.5)Al2O3:(14-20)SiO2:(260-360)H2O, the aluminum source is one of aluminum sulfate, aluminum nitrate, and aluminum chloride, and the silicon source is water glass or silica sol.

[0022] Furthermore, NaY molecular sieves lack mesoporous structures, have a relative crystallinity >95%, and a unit cell constant. Sodium oxide content is 13-15 wt%.

[0023] The present invention also provides a gas-phase ultrastable mesoporous Y molecular sieve, which is prepared by the aforementioned method for preparing gas-phase ultrastable mesoporous Y molecular sieve.

[0024] Furthermore, the gas-phase ultrastable mesoporous Y molecular sieve has a mesopore volume >0.15 cm³. 3 / g, mesoporous pore volume accounts for more than 30% of the total pore volume of gas-phase ultrastable mesoporous Y molecular sieve, relative crystallinity >85%, cell constant < Sodium oxide content <1.8wt%. The basic characteristic of ultra-stable Y-type molecular sieves is cell shrinkage. The relationship between the cell constant and the silicon-to-aluminum ratio of Y-type molecular sieves is that the lower the cell constant, the higher the silicon-to-aluminum ratio. The silicon-to-aluminum ratio directly affects its acid properties; the higher the silicon-to-aluminum ratio, the higher the acid strength and the lower the acid density.

[0025] The present invention also provides a crude oil catalytic cracking catalyst, the active component of which includes the aforementioned gas-phase ultrastable mesoporous Y molecular sieve.

[0026] The fundamental characteristic of wide-range crude oil is the significant difference in hydrocarbon structure. Small-molecule hydrocarbons exhibit high activation energies and are difficult to crack, requiring molecular sieves with high acid strength. Large-molecule hydrocarbons readily undergo hydrogen transfer reactions, forming coke, necessitating molecular sieves with low acid density and mesoporous structures to facilitate rapid diffusion. Gas-phase ultrastable Y-type molecular sieves provide stronger acid centers than conventional Y-type molecular sieves, better promoting the conversion of small-molecule hydrocarbons. Their lower acid density inhibits hydrogen transfer reactions and reduces large-molecule coking. Furthermore, the introduction of mesopores into the gas-phase ultrastable Y-type molecular sieve significantly improves the diffusion of large-molecule hydrocarbons in the feedstock, further promoting feedstock conversion and preventing reaction coking. This makes it suitable as an active component in crude oil catalytic cracking catalysts, significantly improving feedstock conversion rate and target product selectivity, thereby enhancing the economic efficiency of catalytic cracking units. Attached Figure Description

[0027] Figure 1 The TEM image of the gas-phase ultrastable mesoporous Y molecular sieve obtained in Example 1 of the present invention is shown. Detailed Implementation

[0028] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0029] (I) Main raw material sources:

[0030] Water glass: an industrial product with a SiO2 content of 250g / L, produced by Lanzhou Petrochemical.

[0031] Silica sol: Industrial product, SiO2 content 30% by weight, commercially available.

[0032] Aluminum sulfate: Industrial grade, Al2O3 content 90g / L, produced by Lanzhou Petrochemical.

[0033] Aluminum nitrate: analytical grade, purity 99%, commercially available.

[0034] Aluminum chloride: analytical grade, purity 97%, commercially available.

[0035] Sodium hydroxide: analytical grade, purity 96%, commercially available.

[0036] Polyquaternium-6: Aqueous solution, 40% by weight, commercially available.

[0037] Polyquaternium-7: Aqueous solution, 10% by weight, commercially available.

[0038] Silicon tetrachloride: reagent grade, purity 99.99%, commercially available.

[0039] (II) Analytical methods for the molecular sieve performance in the examples and comparative examples:

[0040] The crystallinity of molecular sieves was tested using X-ray powder diffraction, with the standard method being Q / SYLS0596-2002. Approximately 0.3g of the sample to be analyzed was thoroughly ground in an agate mortar for 10 minutes, dried in a 120℃ oven for 2 hours, and then lightly pressed into a flat, uniformly thick sheet for testing. The relative crystallinity was calculated as follows: the ratio of the sum of the peak areas of the eight characteristic peaks corresponding to the (331), (511, 333), (440), (533), (642), (822, 660), (555, 751), and (664) crystal planes to the sum of the corresponding peak areas of the standard sample, multiplied by the crystallinity of the standard sample.

[0041] The cell constant of molecular sieves was determined using X-ray powder diffraction, according to the standard SH / T0339-92. Appropriate amounts of sample and silicon powder were accurately weighed at a weight ratio of 20:1. The mixture was ground in a mortar until homogeneous (at least 10 min), then dried at 120℃ for 2 h. Afterward, it was placed in a humidifier (containing a supersaturated CaCl2 aqueous solution) to absorb moisture for at least 16 h. The sample was then lightly pressed into a flat sheet for measurement, and the cell constant was calculated using the following formula:

[0042]

[0043] Where α is the unit cell constant; λ is the Cu-Kα1 wavelength. (h 2 +k 2 +l 2 ) represents the sum of squares of the Miller indices; θ(correction) represents the position of the sample diffraction peak after correction using the reference value of the diffraction angle of silicon powder (2θ value 28.443).

[0044] The elemental content of molecular sieves was determined using X-ray fluorescence spectrometry, with the method standard Q / SYLS1050-2014. A suitable amount of dried sample was ground in a mortar until it adhered to the mortar wall, then placed into a special mold and pressed firmly to obtain a smooth circular disc, which was then directly tested on the spectrometer.

[0045] The pore volume of the molecular sieve was measured using a Micromeritics ASAP2460 physical adsorption analyzer (manufactured in the USA). The specific method was as follows: approximately 0.2 g of sample was weighed and placed into a sample tube, then pretreated (dehydrated and degassed) at 220°C under vacuum for at least 8 hours. After pretreatment, N2 was added to the sample tube for 15–30 seconds, and then the sample tube was accurately weighed. Finally, the sample tube was placed in the instrument's measuring chamber, and sufficient liquid nitrogen was added to the Dewar flask before the test began. The BET method was used to calculate the sample's specific surface area, and the t-plot method was used to calculate the micropore volume. The difference between the total pore volume and the micropore volume was taken as the mesopore volume.

[0046] (III) Evaluation methods used in the application examples:

[0047] The catalyst performance was evaluated using an Advanced Catalytic Cracking Evaluation Unit (ACE) developed by KTI Technologies, Inc. Prior to evaluation, the catalyst underwent hydrothermal aging treatment under the following conditions: 800℃, 100% steam, for 17 hours. Other reaction conditions were: feedstock Daqing crude oil, catalyst loading 9g, reaction temperature 650℃, regeneration temperature 730℃, and catalyst-to-oil ratio 7.5. The composition of the generated gas, liquid, and coke was analyzed online.

[0048] Example 1

[0049] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0050] 1 L of water glass was used as the silicon source (SiO2 content 250 g / L), and 250 g of polyquaternium-6 was added and stirred until homogeneous. A directing agent was prepared by mixing water glass, aluminum sulfate, and sodium hydroxide solution, with a molar composition of 15.5 Na2O:0.9 Al2O3:16.5 SiO2:310 H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum sulfate were added sequentially to the treated water glass, and stirred to form a gel. The gel had a molar composition of 2.5 Na2O:1.1 Al2O3:9.0 SiO2:220 H2O:0.3 directing agent. The gel was crystallized at 100℃ for 24 h, and after filtration, washing, and drying, the pre-prepared pore-expanding agent NaY molecular sieve was obtained. The obtained NaY molecular sieve had no mesopores, a relative crystallinity of 96%, and a cell constant of [missing value]. Sodium oxide content: 14 wt%.

[0051] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air to a moisture content of 1.0 wt%, and then contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.4:1, the reaction temperature was 430℃, and the reaction time was 0.5 h.

[0052] The molecular sieve after the above reaction was washed, filtered and dried with 90℃ deionized water to make the water content of the molecular sieve 4wt%.

[0053] The dried molecular sieve was then calcined in a muffle furnace at a high temperature of 560℃ for 6 hours to obtain the product, resulting in a mesoporous, ultrastable Y-type molecular sieve (TEM image shown). Figure 1 As shown in the figure, its mesopore volume is 0.19 cm³. 3 / g, mesoporous pore volume accounts for 35% of the total pore volume of the molecular sieve, relative crystallinity is 87%, cell constant is 24.45, and sodium oxide content is 1.6wt%.

[0054] Example 2

[0055] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0056] 1 L of water glass (SiO2 content 250 g / L) was used as the silicon source, and 125 g of polyquaternium-6 was added and stirred until homogeneous. A directing agent was prepared by mixing water glass, aluminum nitrate, and sodium hydroxide solution, with a molar composition of 15.5 Na2O:0.9 Al2O3:16.5 SiO2:310 H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum nitrate were added sequentially to the treated water glass, and stirred to form a gel. The gel had a molar composition of 3.0 Na2O:0.9 Al2O3:8.5 SiO2:200 H2O:0.05 directing agent. The gel was crystallized at 110 °C for 16 h, and after filtration, washing, and drying, the pre-prepared pore-expanding agent NaY molecular sieve was obtained. The obtained NaY molecular sieve was free of mesopores, had a relative crystallinity of 97%, and a cell constant of [missing value]. Sodium oxide content: 13.5 wt%.

[0057] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air to a moisture content of 1.2 wt%, and then contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.3:1, the reaction temperature was 400℃, and the reaction time was 1 h.

[0058] The molecular sieve after the above reaction was washed, filtered, and dried with 95°C deionized water to make the water content of the molecular sieve 3.5wt%.

[0059] The dried molecular sieve was then calcined in a muffle furnace at a high temperature of 580℃ for 4 hours to obtain a mesoporous, ultrastable Y-type molecular sieve with a mesopore volume of 0.16 cm³. 3 / g, mesoporous pore volume accounts for 32% of the total pore volume of the molecular sieve, relative crystallinity is 88%, cell constant is 24.47, and sodium oxide content is 1.7wt%.

[0060] Example 3

[0061] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0062] 1 L of water glass was used as the silicon source (SiO2 content 250 g / L), and 75 g of polyquaternium-7 was added and stirred until homogeneous. A directing agent was prepared by mixing water glass, aluminum chloride, and sodium hydroxide solution, with a molar composition of 15.5 Na2O:0.9 Al2O3:16.5 SiO2:310 H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum chloride were added sequentially to the treated water glass, and stirred to form a gel. The gel had a molar composition of 3.5 Na2O:1.2 Al2O3:7 SiO2:240 H2O:0.2 directing agent. The gel was crystallized at 105 °C for 30 h, and after filtration, washing, and drying, the pre-prepared pore-expanding agent NaY molecular sieve was obtained. The obtained NaY molecular sieve had no mesopores, a relative crystallinity of 97%, and a cell constant of [missing value]. Sodium oxide content: 14.3 wt%.

[0063] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air to a moisture content of 0.9 wt%, and then contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.2:1, the reaction temperature was 380℃, and the reaction time was 1.5 h.

[0064] The molecular sieve after the above reaction was washed, filtered, and dried with deionized water at 85°C to make the water content of the molecular sieve 4.5wt%.

[0065] The dried molecular sieve was then calcined in a muffle furnace at a high temperature of 550℃ for 8 hours to obtain a mesoporous, ultrastable Y-type molecular sieve with a mesopore volume of 0.16 cm³. 3 / g, mesoporous pore volume accounts for 32% of the total pore volume of the molecular sieve, relative crystallinity is 86%, cell constant is 24.44, and sodium oxide content is 1.5wt%.

[0066] Example 4

[0067] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0068] Take 1 kg of silica sol as the silicon source (SiO2 content 30%), add 600 g of polyquaternium-7, and stir well for later use. Prepare a directing agent by mixing silica sol, aluminum sulfate, and sodium hydroxide solution, with a molar composition of 14Na2O:1.2Al2O3:18SiO2:300H2O, and stir well for later use. Add an alkaline solution, directing agent, and aluminum sulfate sequentially to the treated silica sol, stirring to form a gel. The gel has a molar composition of 4Na2O:1.2Al2O3:8SiO2:230H2O:0.1 directing agent. Crystallize the gel at 120℃ for 36 h, and obtain the pre-prepared pore-expanding agent NaY molecular sieve after filtration, washing, and drying. The obtained NaY molecular sieve has no mesopores, a relative crystallinity of 96%, and a cell constant of [missing value]. Sodium oxide content: 14.6 wt%.

[0069] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air to a moisture content of 0.8 wt%, and then contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.1:1, the reaction temperature was 370℃, and the reaction time was 2 h.

[0070] The molecular sieve after the above reaction was washed, filtered, and dried with 100°C deionized water to make the water content of the molecular sieve 3.5wt%.

[0071] The dried molecular sieve was then calcined in a muffle furnace at a high temperature of 570℃ for 10 hours to obtain a mesoporous, ultrastable Y-type molecular sieve with a mesopore volume of 0.21 cm³. 3 / g, mesoporous pore volume accounts for 33% of the total pore volume of the molecular sieve, relative crystallinity is 87%, cell constant is 24.46, and sodium oxide content is 1.7wt%.

[0072] Example 5

[0073] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0074] 1 kg of silica sol (SiO2 content 30%) was used as the silicon source, and 600 g of polyquaternium-6 and 300 g of polyquaternium-7 were added. A directing agent was prepared by mixing silica sol, aluminum nitrate, and sodium hydroxide solution, with a molar composition of 14Na2O:1.2Al2O3:18SiO2:300H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum nitrate were added sequentially to the treated silica sol, and stirred to form a gel. The gel had a molar composition of 4.5Na2O:0.8Al2O3:8.5SiO2:240H2O:0.4 directing agent. The gel was crystallized at 115℃ for 40 h, and after filtration, washing, and drying, NaY molecular sieve with pre-placed pore-expanding agent was obtained. The obtained NaY molecular sieve had no mesopores, a relative crystallinity of 98%, and a cell constant of [missing value]. Sodium oxide content: 13.8 wt%.

[0075] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air to a moisture content of 0.7 wt%, and then contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.25:1, the reaction temperature was 420℃, and the reaction time was 0.2 h.

[0076] The molecular sieve after the above reaction was washed, filtered and dried with 90℃ deionized water to make the water content of the molecular sieve 3wt%.

[0077] The dried molecular sieve was then subjected to high-temperature calcination in a converter at 560℃ for 12 hours to obtain a mesoporous, ultrastable Y-type molecular sieve with a mesopore volume of 0.23 cm³. 3 / g, mesoporous pore volume accounts for 31% of the total pore volume of the molecular sieve, relative crystallinity is 88%, cell constant is 24.43, and sodium oxide content is 1.4wt%.

[0078] Example 6

[0079] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0080] 1 kg of silica sol (SiO2 content 30%) was used as the silicon source, and 100 g of polyquaternium-6 and 200 g of polyquaternium-7 were added. A directing agent was prepared by mixing silica sol, aluminum chloride, and sodium hydroxide solution, with a molar composition of 14Na2O:1.2Al2O3:18SiO2:300H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum chloride were added sequentially to the treated silica sol, and stirred to form a gel. The gel had a molar composition of 3.5Na2O:0.9Al2O3:10SiO2:220H2O:0.25 directing agent. The gel was crystallized at 110℃ for 48 h, and after filtration, washing, and drying, NaY molecular sieve with pre-placed pore-expanding agent was obtained. The obtained NaY molecular sieve had no mesopores, a relative crystallinity of 98%, and a cell constant of [missing value]. Sodium oxide content: 13.6 wt%.

[0081] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air to a moisture content of 1.3 wt%, and then contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.35:1, the reaction temperature was 440℃, and the reaction time was 0.6 h.

[0082] The molecular sieve after the above reaction was washed, filtered, and dried with 95℃ deionized water to make the water content of the molecular sieve 4.8wt%.

[0083] The dried molecular sieve was then subjected to high-temperature calcination in a converter at 590℃ for 5 hours to obtain a mesoporous, ultrastable Y-type molecular sieve with a mesopore volume of 0.20 cm³. 3 / g, mesoporous pore volume accounts for 35% of the total pore volume of the molecular sieve, relative crystallinity is 87%, cell constant is 24.42, and sodium oxide content is 1.6wt%.

[0084] Example 7

[0085] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0086] 1 kJ of silica sol (SiO2 content 30%) was used as the silicon source, and 700 g of polyquaternium-7 was added and stirred evenly for later use. A directing agent was prepared by mixing silica sol, aluminum sulfate, and sodium hydroxide solution, with a molar composition of 14Na2O:1.2Al2O3:18SiO2:300H2O, and stirred evenly for later use. An alkaline solution, the directing agent, and aluminum sulfate were added sequentially to the treated silica sol, and stirred to form a gel. The gel had a molar composition of 4Na2O:1.2Al2O3:8SiO2:230H2O:0.1 directing agent. The gel was crystallized at 120℃ for 36 h, and after filtration, washing, and drying, the pre-prepared pore-expanding agent NaY molecular sieve was obtained. The obtained NaY molecular sieve had no mesopores, a relative crystallinity of 96%, and a cell constant of [missing value]. Sodium oxide content: 14.6 wt%.

[0087] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air to a moisture content of 0.8 wt%, and then contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.1:1, the reaction temperature was 370℃, and the reaction time was 2 h.

[0088] The molecular sieve after the above reaction was washed, filtered, and dried with 100°C deionized water to make the water content of the molecular sieve 3.5wt%.

[0089] The dried molecular sieve was then calcined in a muffle furnace at a high temperature of 570℃ for 10 hours to obtain the product. The resulting molecular sieve product had a mesopore volume of 0.19 cm³. 3 / g, mesoporous pore volume accounts for 29% of the total pore volume of the molecular sieve, relative crystallinity is 62%, cell constant is 24.49, and sodium oxide content is 1.6wt%.

[0090] Compared to Example 4, in Example 7, the ratio of pore-expanding agent to silicon dioxide weight was higher than 3:1 during the preparation of NaY, while other conditions remained the same, resulting in a decrease in the relative crystallinity of the obtained molecular sieve product.

[0091] Example 8

[0092] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0093] 1 L of water glass was used as the silicon source (SiO2 content 250 g / L), and 250 g of polyquaternium-6 was added and stirred until homogeneous. A directing agent was prepared by mixing water glass, aluminum sulfate, and sodium hydroxide solution, with a molar composition of 15.5 Na2O:0.9 Al2O3:16.5 SiO2:310 H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum sulfate were added sequentially to the treated water glass, and stirred to form a gel. The gel had a molar composition of 2.5 Na2O:1.1 Al2O3:9.0 SiO2:220 H2O:0.3 directing agent. The gel was crystallized at 100℃ for 24 h, and after filtration, washing, and drying, the pre-prepared pore-expanding agent NaY molecular sieve was obtained. The obtained NaY molecular sieve had no mesopores, a relative crystallinity of 96%, and a cell constant of [missing value]. Sodium oxide content: 14 wt%.

[0094] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air, and the water content was measured to be 2.5 wt%. Then, it was contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.4:1, the reaction temperature was 430℃, and the reaction time was 0.5 h.

[0095] The molecular sieve after the above reaction was washed, filtered and dried with 90℃ deionized water to make the water content of the molecular sieve 4wt%.

[0096] The dried molecular sieve was then calcined in a muffle furnace at a high temperature of 560℃ for 6 hours to obtain the product. The resulting molecular sieve product had a mesopore volume of 0.17 cm³. 3 / g, mesoporous pore volume accounts for 28% of the total pore volume of the molecular sieve, relative crystallinity is 87%, cell constant is 24.60, and sodium oxide content is 4.6wt%.

[0097] Compared to Example 1, Example 8 uses NaY molecular sieve with pre-placed pore-expanding agent as raw material. During the gas-phase ultrastable reaction with SiCl4, the water content of NaY molecular sieve is >1.5wt%. Under the same conditions, the cell parameters of the obtained product are increased, the cell shrinkage is insufficient, and the sodium oxide content is increased.

[0098] Example 9

[0099] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0100] 1 L of water glass was used as the silicon source (SiO2 content 250 g / L), and 250 g of polyquaternium-6 was added and stirred until homogeneous. A directing agent was prepared by mixing water glass, aluminum sulfate, and sodium hydroxide solution, with a molar composition of 15.5 Na2O:0.9 Al2O3:16.5 SiO2:310 H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum sulfate were added sequentially to the treated water glass, and stirred to form a gel. The gel had a molar composition of 2.5 Na2O:1.1 Al2O3:9.0 SiO2:220 H2O:0.3 directing agent. The gel was crystallized at 100℃ for 24 h, and after filtration, washing, and drying, the pre-prepared pore-expanding agent NaY molecular sieve was obtained. The obtained NaY molecular sieve had no mesopores, a relative crystallinity of 96%, and a cell constant of [missing value]. Sodium oxide content: 14 wt%.

[0101] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air, and the water content was measured to be 1.0 wt%. Then, it was contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.05:1, the reaction temperature was 430℃, and the reaction time was 0.5 h.

[0102] The molecular sieve after the above reaction was washed, filtered and dried with 90℃ deionized water to make the water content of the molecular sieve 4wt%.

[0103] The dried molecular sieve was then calcined in a muffle furnace at a high temperature of 560℃ for 6 hours to obtain the product. The resulting molecular sieve product had a mesopore volume of 0.17 cm³. 3 / g, mesoporous pore volume accounts for 28% of the total pore volume of the molecular sieve, relative crystallinity is 87%, cell constant is 24.58, and sodium oxide content is 3.8wt%.

[0104] Compared to Example 1, Example 9 uses NaY molecular sieve with pre-placed pore-expanding agent as raw material. During the gas-phase ultrastable reaction with SiCl4, the weight ratio of SiCl4 to NaY molecular sieve is less than 0.1:1. Under the same conditions, the cell parameters of the obtained product are increased, the cell shrinkage is insufficient, and the sodium oxide content is increased.

[0105] Example 10

[0106] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0107] 1 L of water glass was used as the silicon source (SiO2 content 250 g / L), and 250 g of polyquaternium-6 was added and stirred until homogeneous. A directing agent was prepared by mixing water glass, aluminum sulfate, and sodium hydroxide solution, with a molar composition of 15.5 Na2O:0.9 Al2O3:16.5 SiO2:310 H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum sulfate were added sequentially to the treated water glass, and stirred to form a gel. The gel had a molar composition of 2.5 Na2O:1.1 Al2O3:9.0 SiO2:220 H2O:0.3 directing agent. The gel was crystallized at 100℃ for 24 h, and after filtration, washing, and drying, the pre-prepared pore-expanding agent NaY molecular sieve was obtained. The obtained NaY molecular sieve had no mesopores, a relative crystallinity of 96%, and a cell constant of [missing value]. Sodium oxide content: 14 wt%.

[0108] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air, and the water content was measured to be 1.0 wt%. Then, it was contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.4:1, the reaction temperature was 340℃, and the reaction time was 0.5 h.

[0109] The molecular sieve after the above reaction was washed, filtered and dried with 90℃ deionized water to make the water content of the molecular sieve 4wt%.

[0110] The dried molecular sieve was then calcined in a muffle furnace at a high temperature of 560℃ for 6 hours to obtain the product. The resulting molecular sieve product had a mesopore volume of 0.16 cm³. 3 / g, mesoporous pore volume accounts for 26% of the total pore volume of the molecular sieve, relative crystallinity is 87%, cell constant is 24.62, and sodium oxide content is 5.8wt%.

[0111] Compared to Example 1, Example 10 uses NaY molecular sieve with pre-placed pore-expanding agent as raw material. During the gas-phase ultrastable reaction with SiCl4, the reaction temperature is below 350°C, and other conditions are the same. The resulting product has increased cell parameters, insufficient cell shrinkage, and increased sodium oxide content.

[0112] Example 11

[0113] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0114] 1 L of water glass was used as the silicon source (SiO2 content 250 g / L), and 250 g of polyquaternium-6 was added and stirred until homogeneous. A directing agent was prepared by mixing water glass, aluminum sulfate, and sodium hydroxide solution, with a molar composition of 15.5 Na2O:0.9 Al2O3:16.5 SiO2:310 H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum sulfate were added sequentially to the treated water glass, and stirred to form a gel. The gel had a molar composition of 2.5 Na2O:1.1 Al2O3:9.0 SiO2:220 H2O:0.3 directing agent. The gel was crystallized at 100℃ for 24 h, and after filtration, washing, and drying, the pre-prepared pore-expanding agent NaY molecular sieve was obtained. The obtained NaY molecular sieve had no mesopores, a relative crystallinity of 96%, and a cell constant of [missing value]. Sodium oxide content: 14 wt%.

[0115] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air, and the water content was measured to be 1.0 wt%. Then, it was contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.4:1, the reaction temperature was 430℃, and the reaction time was 3h.

[0116] The molecular sieve after the above reaction was washed, filtered and dried with 90℃ deionized water to make the water content of the molecular sieve 4wt%.

[0117] The dried molecular sieve was then calcined in a muffle furnace at a high temperature of 560℃ for 6 hours to obtain the product. The resulting molecular sieve product had a mesopore volume of 0.14 cm³. 3 / g, mesoporous pore volume accounts for 23% of the total pore volume of the molecular sieve, relative crystallinity is 69%, cell constant is 24.47, and sodium oxide content is 1.6wt%.

[0118] Compared to Example 1, Example 11 uses NaY molecular sieve with pre-placed pore-expanding agent as raw material. During the gas-phase ultrastable reaction with SiCl4, the reaction time exceeds 2 hours. Under the same conditions, the relative crystallinity of the obtained product is reduced.

[0119] Example 12

[0120] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0121] 1 L of water glass was used as the silicon source (SiO2 content 250 g / L), and 75 g of polyquaternium-7 was added and stirred until homogeneous. A directing agent was prepared by mixing water glass, aluminum chloride, and sodium hydroxide solution, with a molar composition of 15.5 Na2O:0.9 Al2O3:16.5 SiO2:310 H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum chloride were added sequentially to the treated water glass, and stirred to form a gel. The gel had a molar composition of 3.5 Na2O:1.2 Al2O3:7 SiO2:240 H2O:0.2 directing agent. The gel was crystallized at 105 °C for 30 h, and after filtration, washing, and drying, the pre-prepared pore-expanding agent NaY molecular sieve was obtained. The obtained NaY molecular sieve had no mesopores, a relative crystallinity of 97%, and a cell constant of [missing value]. Sodium oxide content: 14.3 wt%.

[0122] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air to a moisture content of 0.9 wt%, and then contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.2:1, the reaction temperature was 380℃, and the reaction time was 1.5 h.

[0123] The molecular sieve after the above reaction was washed, filtered and dried with deionized water at 85℃ to make the water content of the molecular sieve 6wt%.

[0124] The dried molecular sieve was then calcined in a muffle furnace at a high temperature of 550℃ for 8 hours to obtain the product. The resulting molecular sieve product had a mesopore volume of 0.17 cm³. 3 / g, mesoporous pore volume accounts for 33% of the total pore volume of the molecular sieve, relative crystallinity is 67%, cell constant is 24.43, and sodium oxide content is 1.5wt%.

[0125] Compared to Example 3, Example 12 used NaY molecular sieve with pre-placed pore-expanding agent as raw material. After gas-phase ultrastable reaction with SiCl4, the water content was greater than 5 wt% during the washing, filtration and drying process of the molecular sieve. Under the same conditions, the relative crystallinity of the obtained product was reduced.

[0126] Example 13

[0127] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0128] 1 kg of silica sol (SiO2 content 30%) was used as the silicon source, and 100 g of polyquaternium-6 and 200 g of polyquaternium-7 were added. A directing agent was prepared by mixing silica sol, aluminum chloride, and sodium hydroxide solution, with a molar composition of 14Na2O:1.2Al2O3:18SiO2:300H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum chloride were added sequentially to the treated silica sol, and stirred to form a gel. The gel had a molar composition of 3.5Na2O:0.9Al2O3:10SiO2:220H2O:0.25 directing agent. The gel was crystallized at 110℃ for 48 h, and after filtration, washing, and drying, NaY molecular sieve with pre-placed pore-expanding agent was obtained. The obtained NaY molecular sieve had no mesopores, a relative crystallinity of 98%, and a cell constant of [missing value]. Sodium oxide content: 13.6 wt%.

[0129] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air to a moisture content of 1.3 wt%, and then contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.35:1, the reaction temperature was 440℃, and the reaction time was 0.6 h.

[0130] The molecular sieve after the above reaction was washed, filtered, and dried with 95℃ deionized water to make the water content of the molecular sieve 4.8wt%.

[0131] The dried molecular sieve was then subjected to high-temperature calcination in a rotary kiln at 520℃ for 5 hours to obtain a mesoporous, ultrastable Y-type molecular sieve with a mesopore volume of 0.13 cm³. 3 / g, mesoporous pore volume accounts for 26% of the total pore volume of the molecular sieve, relative crystallinity is 87%, cell constant is 24.47, and sodium oxide content is 1.7wt%.

[0132] Compared to Example 6, Example 13 uses NaY molecular sieve with pre-placed pore-expanding agent as raw material and carries out a gas-phase ultrastable reaction with SiCl4. After the molecular sieve is washed, filtered, and dried, the calcination temperature is lower than 540°C, and other conditions are the same. The resulting product has a reduced mesopore size.

[0133] Example 14

[0134] This embodiment provides a method for preparing gas-phase ultrastable mesoporous Y molecular sieves, including:

[0135] 1 kg of silica sol (SiO2 content 30%) was used as the silicon source, and 100 g of polyquaternium-6 and 200 g of polyquaternium-7 were added. A directing agent was prepared by mixing silica sol, aluminum chloride, and sodium hydroxide solution, with a molar composition of 14Na2O:1.2Al2O3:18SiO2:300H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum chloride were added sequentially to the treated silica sol, and stirred to form a gel. The gel had a molar composition of 3.5Na2O:0.9Al2O3:10SiO2:220H2O:0.25 directing agent. The gel was crystallized at 110℃ for 48 h, and after filtration, washing, and drying, NaY molecular sieve with pre-placed pore-expanding agent was obtained. The obtained NaY molecular sieve had no mesopores, a relative crystallinity of 98%, and a cell constant of [missing value]. Sodium oxide content: 13.6 wt%.

[0136] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air to a moisture content of 1.3 wt%, and then contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.35:1, the reaction temperature was 440℃, and the reaction time was 0.6 h.

[0137] The molecular sieve after the above reaction was washed, filtered, and dried with 95℃ deionized water to make the water content of the molecular sieve 4.8wt%.

[0138] The dried molecular sieve was then subjected to high-temperature calcination in a converter at 600℃ for 2.5 hours to obtain a mesoporous, ultrastable Y-type molecular sieve with a mesopore volume of 0.12 cm³. 3 / g, mesoporous pore volume accounts for 24% of the total pore volume of the molecular sieve, relative crystallinity is 87%, cell constant is 24.46, and sodium oxide content is 1.6wt%.

[0139] Compared to Example 6, Example 14 uses NaY molecular sieve with pre-placed pore-expanding agent as raw material and carries out a gas-phase ultrastable reaction with SiCl4. After the molecular sieve is washed, filtered, and dried, the calcination temperature is higher than 590°C. Other conditions are the same, and the resulting product has fewer mesopores.

[0140] Comparative Example 1

[0141] This comparative example provides a method for preparing gas-phase ultrastable Y molecular sieves, including:

[0142] 1 L of water glass was used as the silicon source (SiO2 content 250 g / L) for later use. A directing agent was prepared by mixing water glass, aluminum sulfate, and sodium hydroxide solution, with a molar composition of 15.5 Na2O:0.9 Al2O3:16.5 SiO2:310 H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum sulfate were added sequentially to the treated water glass, and the mixture was stirred to form a gel. The gel had a molar composition of 2.5 Na2O:1.1 Al2O3:9.0 SiO2:220 H2O:0.3 directing agent. The gel was crystallized at 100℃ for 24 h, and after filtration, washing, and drying, NaY molecular sieves were obtained. The obtained NaY molecular sieves were free of mesopores, had a relative crystallinity of 96%, and a cell constant of [missing value]. Sodium oxide content: 14 wt%.

[0143] Using the above-mentioned NaY molecular sieve as raw material, it was first dried with hot dry air to make the water content 1.0 wt%, and then it was contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.4:1, the reaction temperature was 430℃, and the reaction time was 0.5 h.

[0144] The molecular sieve after the above reaction was washed, filtered and dried with 90℃ deionized water to make the water content of the molecular sieve 4wt%.

[0145] The dried molecular sieve was then calcined in a muffle furnace at a high temperature of 560℃ for 6 hours to obtain the product. The resulting molecular sieve product had a mesopore volume of 0.02 cm³. 3 / g, mesoporous pore volume accounts for 4% of the total pore volume of the molecular sieve, relative crystallinity is 88%, cell constant is 24.44, and sodium oxide content is 1.6wt%.

[0146] Compared to Example 1, Comparative Example 1 did not add a pore-expanding agent during the preparation of NaY, and all other conditions were the same. The resulting product had very few mesopores and could not obtain a mesoporous ultrastable Y molecular sieve.

[0147] Comparative Example 2

[0148] This comparative example provides a method for preparing gas-phase ultrastable Y molecular sieves, including:

[0149] 1 L of water glass was used as the silicon source (SiO2 content 250 g / L), and 50 g of polyquaternium-6 was added and stirred until homogeneous. A directing agent was prepared by mixing water glass, aluminum nitrate, and sodium hydroxide solution, with a molar composition of 15.5 Na2O:0.9 Al2O3:16.5 SiO2:310 H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum nitrate were added sequentially to the treated water glass, and stirred to form a gel. The gel had a molar composition of 3.0 Na2O:0.9 Al2O3:8.5 SiO2:200 H2O:0.05 directing agent. The gel was crystallized at 110 °C for 16 h, and after filtration, washing, and drying, the pre-prepared pore-expanding agent NaY molecular sieve was obtained. The obtained NaY molecular sieve was free of mesopores, had a relative crystallinity of 97%, and a cell constant of [missing value]. Sodium oxide content: 13.5 wt%.

[0150] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air to a moisture content of 1.2 wt%, and then contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.3:1, the reaction temperature was 400℃, and the reaction time was 1 h.

[0151] The molecular sieve after the above reaction was washed, filtered, and dried with 95°C deionized water to make the water content of the molecular sieve 3.5wt%.

[0152] The dried molecular sieve was then calcined in a muffle furnace at a high temperature of 580℃ for 4 hours to obtain the product. The resulting molecular sieve product had a mesopore volume of 0.06 cm³. 3 / g, mesoporous pore volume accounts for 11% of the total pore volume of the molecular sieve, relative crystallinity is 89%, cell constant is 24.45, and sodium oxide content is 1.8wt%.

[0153] Compared to Example 2, in the preparation of NaY, the ratio of the amount of pore expander added to the weight of silicon oxide in Comparative Example 2 was less than 0.3:1, while other conditions were the same, and the resulting molecular sieve product had very few mesopores.

[0154] Comparative Example 3

[0155] This comparative example provides a method for preparing gas-phase ultrastable Y molecular sieves, including:

[0156] 1 kg of silica sol (SiO2 content 30%) was used as the silicon source, and 600 g of polyquaternium-6 and 300 g of polyquaternium-7 were added. A directing agent was prepared by mixing silica sol, aluminum nitrate, and sodium hydroxide solution, with a molar composition of 14Na2O:1.2Al2O3:18SiO2:300H2O, and stirred until homogeneous. An alkaline solution, the directing agent, and aluminum nitrate were added sequentially to the treated silica sol, and stirred to form a gel. The gel had a molar composition of 4.5Na2O:0.8Al2O3:8.5SiO2:240H2O:0.4 directing agent. The gel was crystallized at 115℃ for 40 h, and after filtration, washing, and drying, NaY molecular sieve with pre-placed pore-expanding agent was obtained. The obtained NaY molecular sieve had no mesopores, a relative crystallinity of 98%, and a cell constant of [missing value]. Sodium oxide content: 13.8 wt%.

[0157] Using the aforementioned pre-prepared pore-expanding agent NaY molecular sieve as raw material, it was first dried with hot dry air to a moisture content of 0.7 wt%, and then contacted with SiCl4 to carry out a gas-phase ultrastable reaction. The weight ratio of SiCl4 to NaY molecular sieve was 0.25:1, the reaction temperature was 420℃, and the reaction time was 0.2 h.

[0158] The molecular sieve after the above reaction was washed, filtered, and dried with deionized water at 90℃, so that the water content of the molecular sieve was 3wt%, to obtain the molecular sieve product with a mesopore volume of 0.04 cm³. 3 / g, mesoporous pore volume accounts for 5% of the total pore volume of the molecular sieve, relative crystallinity is 86%, cell constant is 24.51, and sodium oxide content is 1.7wt%.

[0159] Compared to Example 5, Comparative Example 3 used NaY molecular sieve with pre-added pore-expanding agent as raw material and carried out a gas-phase ultrastable reaction with SiCl4. After the molecular sieve was washed, filtered and dried, no calcination process was carried out. Under the same conditions, the obtained molecular sieve product had very few mesopores.

[0160] Application Examples

[0161] 100g of the mesoporous gas-phase ultrastable Y-type molecular sieve from Example 1, 300g of HZSM-5 molecular sieve, 450g of kaolin, 750g of alumina sol (Al2O3 weight content 20%), and 4kg of deionized water were mixed and pulped, and spray-dried to obtain a crude oil direct catalytic cracking catalyst for producing low-carbon olefins, denoted as CAT1. After hydrothermal aging at 800℃ for 17h, the ACE evaluation results showed that the crude oil conversion rate was 91wt%, and the single-pass yield of trienes (ethylene + propylene + butene) was 47wt%.

[0162] Application of comparative examples

[0163] 100g of the gas-phase ultrastable Y-type molecular sieve, 300g of HZSM-5 molecular sieve, 450g of kaolin, 750g of alumina sol (Al2O3 weight content 20%) from Comparative Example 1 were mixed with 4kg of deionized water and pulped. The mixture was then spray-dried to obtain a catalyst for the direct catalytic cracking of crude oil to produce low-carbon olefins, denoted as D-CAT1. After hydrothermal aging at 800℃ for 17h, the ACE evaluation results showed that the crude oil conversion rate was 82wt% and the single-pass yield of trienes (ethylene + propylene + butene) was 39wt%.

Claims

1. A method for preparing a gas-phase ultrastable mesoporous Y molecular sieve, wherein, include: To prepare NaY molecular sieves, a pore-expanding agent is added during the preparation process to obtain NaY molecular sieves in which the pore-expanding agent is pre-coated inside the crystal grains. The NaY molecular sieve is subjected to a gas-phase ultrastable reaction with SiCl4, and the product of the gas-phase ultrastable reaction is calcined to remove the pore-expanding agent, thereby obtaining the gas-phase ultrastable mesoporous Y molecular sieve. The pore-expanding agent is a water-soluble cationic polymer; the raw material for preparing NaY molecular sieves is SiO2, and the weight ratio of the pore-expanding agent to the raw material for preparing NaY molecular sieves is greater than or equal to 0.

3.

2. The method for preparing gas-phase ultrastable mesoporous Y molecular sieve according to claim 1, wherein, The pore-expanding agent is polyquaternium-6 and / or polyquaternium-7.

3. The method for preparing gas-phase ultrastable mesoporous Y molecular sieve according to claim 1 or 2, wherein, The raw materials for preparing NaY molecular sieves are calculated based on SiO2, and the weight ratio of the pore-expanding agent to the raw materials for preparing NaY molecular sieves is 0.3 to 3:

1.

4. The method for preparing gas-phase ultrastable mesoporous Y molecular sieve according to claim 1 or 2, wherein, The weight ratio of SiCl4 to NaY molecular sieve is 0.1 to 0.5:

1.

5. The method for preparing gas-phase ultrastable mesoporous Y molecular sieve according to claim 1 or 2, wherein, The roasting process is carried out at a temperature of 540–590°C for 4–12 hours.

6. The method for preparing gas-phase ultrastable mesoporous Y molecular sieve according to claim 1, wherein, The water content of the NaY molecular sieve is <1.5wt%.

7. The method for preparing gas-phase ultrastable mesoporous Y molecular sieve according to claim 1, wherein, The water content of the product of the gas-phase ultrastable reaction is <5 wt%.

8. The method for preparing gas-phase ultrastable mesoporous Y molecular sieve according to claim 1, wherein, The reaction temperature of the gas-phase ultrastable reaction is 350–500℃, and the reaction time is 0.1–2 h.

9. The method for preparing gas-phase ultrastable mesoporous Y molecular sieve according to claim 1, wherein, The raw materials for preparing NaY molecular sieves include a silicon source, an alkaline solution, a directing agent, and an aluminum source; the process for preparing NaY molecular sieves includes the following steps: The silicon source and the pore-expanding agent are mixed to form a mixed system; An alkaline solution, a directing agent, and an aluminum source are added to the mixture to form a gel system; The gel system is crystallized at a temperature of 70–120°C for 8–48 hours to form a crystallized system. The crystallization system is sequentially filtered, washed, and dried to obtain the NaY molecular sieve. The molar composition of the gel system is (2-5)Na2O:(0.7-1.3)Al2O3:(6-12)SiO2:(100-250)H2O:(0.05-0.5)directing agent.

10. The method for preparing gas-phase ultrastable mesoporous Y molecular sieve according to claim 9, wherein, The NaY molecular sieve has no mesopores, a relative crystallinity >95%, and a unit cell constant. Sodium oxide content is 13-15 wt%.

11. A gas-phase ultrastable mesoporous Y molecular sieve, wherein, It is prepared by the method for preparing gas-phase ultrastable mesoporous Y molecular sieve according to any one of claims 1 to 10.

12. The gas-phase ultrastable mesoporous Y molecular sieve according to claim 11, wherein, Mesopore volume > 0.15 cm³ 3 / g, the mesoporous pore volume accounts for more than 30% of the total pore volume of the gas-phase ultrastable mesoporous Y molecular sieve, the relative crystallinity is >85%, and the unit cell constant is Sodium oxide content <1.8 wt%.

13. A crude oil catalytic cracking catalyst, wherein, The active component of the crude oil catalytic cracking catalyst includes the gas-phase ultrastable mesoporous Y molecular sieve as described in claim 11 or 12.

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