A low-carbon olefin additive for promoting heavy oil conversion, its preparation method, catalyst, and method for catalytic conversion of hydrocarbon oil.

Abstract

This disclosure relates to a low-carbon olefin additive for promoting heavy oil conversion, its preparation method, catalyst, and method for catalytic conversion of hydrocarbon oils. Based on the dry weight of the additive, the additive contains 25-75 wt% molecular sieve, 0.5-8 wt% metal components (based on metal oxides), 3-40 wt% phosphorus-aluminum binder (based on oxides), 1-25 wt% other inorganic binders (based on oxides), and 0-30 wt% clay. The additive provided by this disclosure can effectively increase the propylene and butene content in catalytic cracking liquefied petroleum gas (LPG), improve the olefin content in LPG, reduce the sum of diesel and slurry oil yields, and increase the sum of gasoline and LPG yields.

Description

Technical Field

[0001] This application relates to a low-carbon olefin additive for promoting heavy oil conversion, its preparation method, catalyst, and method for catalytic conversion of hydrocarbon oil. Background Technology

[0002] For most catalytic cracking units, adding catalysts is an effective technical approach to increase the production of low-carbon olefins, and the acidity of the catalyst and the shape-selective effect of the pores determine the yield of low-carbon olefins in the product.

[0003] Prior art discloses a five-membered ring high-silica zeolite catalyst for light olefins in a fluidized bed catalytic cracking unit. The catalyst comprises (a) a five-membered ring high-silica zeolite, (b) 8-24 wt% phosphorus, calculated as P2O5 based on the five-membered ring high-silica zeolite particles, and 1-10 wt% iron oxide, calculated as Fe2O3, located outside the five-membered ring high-silica zeolite framework. The catalyst is fluidizable and has an average particle size of about 20-200 micrometers. The catalyst composition can increase the yield of light olefins such as propylene in fluidized bed catalytic cracking (FCC), but increases propylene yield while decreasing gasoline yield. A cracking catalyst for increasing propylene concentration is disclosed in the prior art. This catalyst, on a dry basis, consists of 10-65 wt% modified ZSM-5 molecular sieve, 0-60 wt% clay, 15-60 wt% inorganic oxide binder, 0.5-15 wt% metal additives selected from one or more Group VIIIB metals, and 2-25 wt% phosphorus additives. The modified ZSM-5 molecular sieve is modified with phosphorus and a metal selected from Fe, Co, or Ni. Its anhydrous chemical expression, on an oxide basis, is (0-0.3)Na₂O·(0.5-5)Al₂O₃·(1.3-10)P₂O₅·(0.7-15)M x O y (70-97)SiO2, where x represents the number of atoms of M, and y represents a number required to satisfy the oxidation state of M. The metal and phosphorus additives mentioned are both based on oxides. This cracking catalyst, when applied to the catalytic cracking process of petroleum hydrocarbons, significantly increases the yield of liquefied petroleum gas (LPG) and the octane number of gasoline, while also significantly increasing the propylene concentration in LPG. However, the gasoline yield decreases markedly, while the diesel and slurry yields do not decrease.

[0004] β-zeolite has three intersecting 12-membered ring channels. The 12-membered ring pores of the one-dimensional channel parallel to the (001) crystal plane have a diameter of 0.57–0.75 nm, while the 12-membered ring pores of the two-dimensional channel parallel to the (100) crystal plane have a diameter of 0.56–0.65 nm. Due to its unique pore structure, high acidity, and good hydrothermal stability, β-zeolite has broad prospects for industrial application and has been successfully applied in petrochemical fields such as isomerization, catalytic cracking, and alkylation of aromatics. Existing technology discloses a β-zeolite containing phosphorus and transition metals, a cracking aid for increasing the concentration of low-carbon olefins in catalytic cracking, and its preparation method. This aid, when applied to catalytic cracking, can increase the concentration of ethylene in catalytic cracking dry gas and the concentration of propylene and isobutylene in liquefied petroleum gas. However, the main problems with the use of β-zeolite are that its structure is easily damaged during the removal of its template agent, and its selectivity for propylene as a catalyst when used alone as an active component is poor. Summary of the Invention

[0005] The purpose of this disclosure is to provide a low-carbon olefin additive for promoting heavy oil conversion, its preparation method, catalyst, and method for catalytic conversion of hydrocarbon oil. The additive disclosed herein can effectively increase the content of propylene and butene in liquefied petroleum gas (LPG), increase the olefin content in LPG, and at the same time promote diesel conversion and reduce gasoline loss.

[0006] To achieve the above objectives, the first aspect of this disclosure provides a low-carbon olefin additive for promoting heavy oil conversion, the additive containing 25-75% by weight of molecular sieve, 0.5-8% by weight of metal component based on metal oxide, 3-40% by weight of phosphorus aluminum binder based on oxide, 1-25% by weight of other inorganic binder based on oxide and 0-30% by weight of clay.

[0007] The molecular sieve contains MFI structured molecular sieve and BEA structured molecular sieve, the molecular sieve contains a first phosphorus component, the phosphorus aluminum binder contains a second phosphorus component, and the total content of the first phosphorus component and the second phosphorus component in the additive, calculated as P2O5, is 10-35% by weight; the pore volume of the additive, as determined by the BJH method, is greater than 0.12 mL / g.

[0008] Based on the total weight of the phosphorus aluminum binder, the phosphorus aluminum binder contains 3-15% by weight Al2O3, 15-40% by weight P2O5, and 0.1-10% by weight stabilizer; the P / Al weight ratio of the phosphorus aluminum binder is 1.6-6, the pH value is 0.5-2.5, and the QPO is [not specified]. 2 / QP0 0 The range is 1-5, where QP0 2 Indicates by 31P-NMR spectroscopy analysis of the phosphorus aluminum binder yielded a resonance signal peak area with a chemical shift of 12 ± 2 ppm, QP0. 0 The area of ​​the resonance signal peak with a chemical shift of 0±2ppm is indicated, and the average particle size of the phosphorus aluminum binder is 10-30nm.

[0009] Optionally, the aluminum phosphorus binder contains 3-12% by weight of Al₂O₃, 15-32% by weight of P₂O₅, and 0.5-5% by weight of stabilizer; the P / Al weight ratio of the aluminum phosphorus binder is 1.7-5.8, the pH value is 0.5-2.5, and the QPO is [not specified]. 2 / QP0 0 The solid content of the aluminum phosphate binder is 1.5-5% by weight.

[0010] Optionally, based on the dry weight of the additive, the content of the molecular sieve is 30-65% by weight, the content of the metal component is 1-5% by weight, the content of the phosphorus aluminum binder (calculated as oxide) is 8-32% by weight, the content of the other inorganic binders (calculated as oxide) is 2-20% by weight, and the content of the clay is 1-25% by weight.

[0011] Optionally, the other inorganic binder is selected from one or more of boehmite, alumina, aluminum sol, silica-alumina sol, and silica sol;

[0012] The clay is selected from one or more of kaolin, sepiolite, attapulgite, rettoite, montmorillonite, and diatomite.

[0013] The MFI molecular sieve and the BEA-structured molecular sieve are each independently selected from one or more of hydrogen-type molecular sieves, phosphorus-containing molecular sieves, and phosphorus- and transition metal-containing molecular sieves.

[0014] Preferably, the MFI structured molecular sieve is a hierarchical ZSM-5 molecular sieve, wherein the silica-alumina ratio of the hierarchical ZSM-5 molecular sieve is 20-70, the pore volume of pores with a diameter of 2-50 nm accounts for 40-70% of the total pore volume, the pore volume of pores with a diameter of 2-20 nm accounts for more than 85% of the total mesopore volume, the pore volume measured by the BJH method is greater than 0.25 mL / g, and the micropore volume is greater than 0.1 cc / g;

[0015] Preferably, the BEA-structured molecular sieve is a β-molecular sieve, and the microporous specific surface area of ​​the β-molecular sieve is 450-500 m². 2 / gram, the mesopore volume of the β molecular sieve accounts for 35-60% of the total pore volume; the strong acid content of the molecular sieve accounts for 25-55% of the total acid content, and the ratio of β acid content to L acid content is 35-75;

[0016] The weight ratio of the BEA structure molecular sieve to the MFI structure molecular sieve in the molecular sieve is (0.01-100):1;

[0017] The metal in the metal component is selected from at least one of Group VIII metals, preferably one or more of Fe, Co, and Ni. The MFI structured molecular sieve and / or BEA structured molecular sieve may contain modified metals, which are not included in the metal component but are considered part of the molecular sieve component. Preferably, the total content of the modified metal and the metal component in the molecular sieve is 0.5-8% by weight.

[0018] A second aspect of this disclosure provides a method for preparing the low-carbon olefin auxiliaries provided in the first aspect of this disclosure, the method comprising:

[0019] S1. Mix the molecular sieve, the other inorganic binder, the clay, the metal source and water to form a slurry, and control the pH value of the slurry to be greater than 2.5 to obtain the first slurry.

[0020] S2. After mixing the first slurry with the phosphorus aluminum binder, spray drying and calcination are carried out to obtain the additive.

[0021] Optionally, the phosphorus aluminum binder is prepared by a method comprising the following steps:

[0022] (1) Under stirring conditions at 50-95℃, aluminum source, water and stabilizer are mixed to obtain an alumina precursor solution with a solid content of 5-40% by weight.

[0023] (2) The alumina precursor solution is mixed with phosphate at a temperature of 25-70℃ and under stirring conditions to obtain the phosphate-aluminum binder.

[0024] Optionally, the aluminum source is selected from one or more of aluminum nitrate, aluminum sulfate, and aluminum chloride;

[0025] The phosphate is diamine hydrogen phosphate and / or ammonium dihydrogen phosphate;

[0026] The stabilizer is selected from one or more of acetic acid, glycolic acid, oxalic acid, malonic acid, malic acid, tartaric acid, succinic acid, adipic acid, maleic acid, itaconic acid and citric acid, preferably acetic acid or citric acid.

[0027] The metal source is one or more of iron salts, cobalt salts, and nickel salts, preferably FeCl3·6H2O. A third aspect of this disclosure provides a catalyst comprising an auxiliary agent and an optional main catalyst, wherein the auxiliary agent is the one provided in the first aspect of this disclosure.

[0028] The fourth aspect of this disclosure provides a method for the catalytic conversion of hydrocarbon oil, the method comprising: contacting the hydrocarbon oil with an additive provided in the first aspect of this disclosure or a catalyst provided in the third aspect of this disclosure to react.

[0029] Optionally, the reaction conditions include: a temperature of 300-700°C and a weight hourly space velocity of 4-120 h⁻¹. -1 The weight ratio of the agent to oil is 1-20.

[0030] Through the above technical solution, the additive disclosed herein contains a specific phosphorus-aluminum binder. This phosphorus-aluminum binder has fewer free phosphate groups and more polymerized phosphate groups, resulting in good binding performance and a long service life. This phosphorus-aluminum binder has a synergistic effect with the molecular sieve, enabling the additive disclosed herein to effectively increase the propylene and butene content in liquefied petroleum gas (LPG), increase the olefin content in LPG, promote diesel cracking, and reduce gasoline loss, thereby reducing the combined yield of diesel and slurry oil and increasing the combined yield of gasoline and LPG.

[0031] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0032] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0033] Figure 1 These are the NMR spectra of the aluminum phosphorus binder prepared in Example 1 of this disclosure and the NMR spectra of the aluminum phosphorus binder prepared in Comparative Example 1. Detailed Implementation

[0034] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0035] The first aspect of this disclosure provides a low-carbon olefin additive for promoting heavy oil conversion, wherein, based on the dry weight of the additive, the additive contains 25-75% by weight of molecular sieve, 1-8% by weight of metal component (calculated as metal oxide), 3-40% by weight of phosphorus aluminum binder (calculated as oxide), 1-25% by weight of other inorganic binder (calculated as oxide) and 0-30% by weight of clay.

[0036] The molecular sieve contains MFI structured molecular sieve and BEA structured molecular sieve, the molecular sieve contains a first phosphorus component, the phosphorus aluminum binder contains a second phosphorus component, and the total content of the first phosphorus component and the second phosphorus component in the additive, calculated as P2O5, is 10-35% by weight; the pore volume of the additive, as determined by the BJH method, is greater than 0.12 mL / g.

[0037] Based on the total weight of the phosphorus aluminum binder, the phosphorus aluminum binder contains 3-15% by weight Al2O3, 15-40% by weight P2O5, and 0.1-10% by weight stabilizer; the P / Al weight ratio of the phosphorus aluminum binder is 1.6-6, the pH value is 0.5-2.5, and the QPO is [not specified]. 2 / QP0 0 The range is 1-5, where QP0 2 Indicates by 31 P-NMR spectroscopy analysis of the phosphorus aluminum binder yielded a resonance signal peak area with a chemical shift of 12 ± 2 ppm, QP0. 0 The area of ​​the resonance signal peak with a chemical shift of 0±2ppm is indicated, and the average particle size of the phosphorus aluminum binder is 10-30nm.

[0038] The additive disclosed herein contains a specific phosphorus-aluminum binder with fewer free phosphate groups and more polymerized phosphate groups, resulting in good binding performance and a long service life. It also reduces interaction with aluminum in the molecular sieve, thus improving the activity and hydrothermal stability of the molecular sieve. This phosphorus-aluminum binder has a synergistic effect with the molecular sieve, effectively increasing the propylene and butene content in gasoline, enhancing the olefin content in LPG, promoting heavy oil conversion, reducing diesel and slurry oil yields, and increasing gasoline and LPG yields.

[0039] In this disclosure, the pore volume and total pore volume determined by the BJH method refer to the pore volume measured by the nitrogen adsorption capacity method; for specific methods, please refer to the pore volume and pore size distribution determined by the nitrogen adsorption capacity method in RIPP151-90.

[0040] According to this disclosure, the average particle size of the aluminum phosphorus binder is obtained by transmission electron microscopy (TEM). Specifically, the aluminum phosphorus binder is analyzed by TEM, 100 aluminum phosphorus binder particles are randomly selected from the TEM image, and their largest diameter is measured as their particle size. The average particle size of the 100 aluminum phosphorus binder particles is calculated.

[0041] In a preferred embodiment of this disclosure, the aluminum phosphorus binder contains 3-12% by weight of Al₂O₃, 15-32% by weight of P₂O₅, and 0.1-5% by weight of stabilizer; the P / Al weight ratio of the aluminum phosphorus binder is 1.7-5.8, the pH value is 0.5-2.5, and the QPO is [not specified]. 2 / QP0 0 It is 1.5-5.

[0042] In one specific embodiment of this disclosure, the solid content of the aluminum phosphate binder is 15-50% by weight, preferably 20-45% by weight.

[0043] In one specific embodiment of this disclosure, based on the dry weight of the additive, the content of the molecular sieve is 30-65% by weight, the content of the metal component is 1-5% by weight, the content of the phosphorus-aluminum binder (calculated as oxide) is 8-32% by weight, the content of the other inorganic binders (calculated as oxide) is 2-20% by weight, and the content of the clay is 1-25% by weight; more preferably, the content of the molecular sieve is 40-60% by weight, the content of the metal component is 0.5-5% by weight, the content of the phosphorus-aluminum binder (calculated as oxide) is 20-30% by weight, the content of the other inorganic binders (calculated as oxide) is 10-18% by weight, and the content of the clay is 5-10% by weight. The additive having the above composition has superior catalytic performance, can further improve the yield of low-carbon olefins, promote the conversion of heavy oil, and reduce coke and slurry.

[0044] In one specific embodiment of this disclosure, the total content of the first phosphorus component and the second phosphorus component, calculated as P2O5, in the additive is 15-25% by weight; the pore volume of the additive, as determined by the BJH method, is 0.12-0.14 mL / g.

[0045] According to this disclosure, other inorganic binders can be those conventionally used by those skilled in the art in the preparation of catalysts. In one specific embodiment of this disclosure, the other inorganic binder is one or more selected from boehmite, alumina, aluminum sol, silica-alumina sol, and silica sol.

[0046] According to this disclosure, the clay can be any material conventionally used by those skilled in the art in the preparation of catalysts. In one specific embodiment of this disclosure, the clay is selected from one or more of kaolin, sepiolite, attapulgite, rettoiter, montmorillonite, and diatomaceous earth.

[0047] According to this disclosure, the MFI structured molecular sieve and the BEA structured molecular sieve are each independently selected from one or more of hydrogen-form molecular sieves, phosphorus-containing molecular sieves, and phosphorus- and transition metal-containing molecular sieves. In one embodiment, at least one of the MFI structured molecular sieve and the BEA structured molecular sieve contains phosphorus; preferably, the MFI structured molecular sieve and the BEA structured molecular sieve are each independently phosphorus- and transition metal-containing molecular sieves, that is, the MFI molecular sieve may simultaneously contain phosphorus and transition metals, and the BEA structured molecular sieve may simultaneously contain phosphorus and transition metals.

[0048] In a preferred embodiment, the MFI structured molecular sieve is a hierarchical ZSM-5 molecular sieve, wherein the silica-alumina ratio of the hierarchical ZSM-5 molecular sieve is 20-70, the pore volume measured by the BJH method is greater than 0.25 mL / g, the pore volume of pores with a diameter of 2-50 nm accounts for 40-70% of the total pore volume, the pore volume of pores with a diameter of 2-20 nm accounts for more than 85% of the total mesopore volume, and the micropore volume is greater than 0.1 cc / g.

[0049] In a preferred embodiment, the BEA-structured molecular sieve is a β-molecular sieve, and the microporous specific surface area of ​​the β-molecular sieve is 450-500 m². 2 / gram, the mesopore volume of the β molecular sieve accounts for 35-60% of the total pore volume; the strong acid content of the molecular sieve accounts for 25-55% of the total acid content, and the ratio of Brønsted acid content to Lewis acid content is 35-75.

[0050] According to this disclosure, the pore volume, total pore volume, and micropore volume determined by the BJH method are the pore volumes measured according to the RIPP 151-90 method (see Petrochemical Analysis Methods, Determination of Pore Volume and Pore Size Distribution of Catalysts by Nitrogen Adsorption Capacitance Method, edited by Yang Cuiding et al., Petrochemical Analysis Methods (RIPP Experimental Methods), Science Press, 1990).

[0051] In one specific embodiment of this disclosure, the weight ratio of the BEA-structured molecular sieve to the MFI-structured molecular sieve is (0.01-100):1, preferably (0.1-30):1, and more preferably (0.25-6):1. When the molecular sieve adopts the above-mentioned ratio of BEA-structured and MFI-structured molecular sieves, the additive's effect on the content of propylene and butene in liquefied petroleum gas (LPG) can be further improved, the olefin content in LPG can be increased, diesel cracking can be promoted, and gasoline loss can be reduced, thereby reducing the sum of the yields of diesel and slurry oil and increasing the sum of the yields of gasoline and LPG.

[0052] According to this disclosure, the metal in the metal component is selected from at least one of Group VIII metals, preferably one or more of Fe, Co and Ni.

[0053] The second aspect of this disclosure provides a method for preparing the additive provided in the first aspect of this disclosure, the method comprising: S1, mixing the molecular sieve, the other inorganic binder, the clay, the metal source and water to form a slurry, controlling the pH value of the slurry to be greater than 2.5, to obtain a first slurry; S2, mixing the first slurry with the phosphorus aluminum binder, and then spray drying and calcining to obtain the additive.

[0054] The method disclosed herein can prepare an additive with superior catalytic performance. This additive can effectively increase the content of propylene and butene in catalytic cracking liquefied petroleum gas, improve the olefin content in LPG, reduce the yield of diesel and slurry oil, and increase the sum of the yields of gasoline and LPG.

[0055] In one specific embodiment of this disclosure, in step S1, the molecular sieve, the clay and water are first mixed and pulped, and then the other inorganic binder is added to the resulting mixture for further mixing and pulping to obtain the first slurry, which is beneficial to further improve the activity and strength of the additives.

[0056] According to this disclosure, spray drying is a technique well known to those skilled in the art, and specific methods will not be described in detail here. In one specific embodiment, the inlet temperature of the spray dryer can be 300-700°C, and the outlet temperature can be 80-200°C.

[0057] In one specific embodiment of this disclosure, the calcination temperature is 400-700℃, preferably 450-600℃, and the calcination time is 0.5-100 hours, preferably 0.5-10 hours.

[0058] In one specific embodiment of this disclosure, the aluminum phosphate binder is prepared by a method comprising the following steps: (1) mixing an aluminum source, water, and a stabilizer at 50-95°C with stirring to obtain an alumina precursor solution with a solid content of 5-40% by weight; (2) reacting the alumina precursor solution with phosphate at 25-70°C with stirring to obtain the aluminum phosphate binder. In one embodiment, the reaction time in step (2) can vary within a wide range, as long as the alumina precursor solution and phosphate react to form a transparent colloid, for example, 10-60 minutes.

[0059] The method disclosed herein uses a phosphorus-aluminum binder prepared from low-cost aluminum salts and phosphates. This phosphorus-aluminum binder has few free phosphate groups and many polymerized phosphate groups, resulting in good bonding performance. Furthermore, it contains a stabilizer that can effectively extend the service life of the phosphorus-aluminum binder.

[0060] In one specific embodiment of this disclosure, the aluminum source is selected from one or more of aluminum nitrate, aluminum sulfate, and aluminum chloride; the phosphate is diamine hydrogen phosphate and / or ammonium dihydrogen phosphate; the stabilizer is selected from one or more of acetic acid, glycolic acid, oxalic acid, malonic acid, malic acid, tartaric acid, succinic acid, adipic acid, maleic acid, itaconic acid, and citric acid, preferably acetic acid or citric acid; the metal source contains a soluble metal salt of Group VIII metals, such as one or more of iron salts, cobalt salts, and nickel salts, preferably FeCl3·6H2O.

[0061] A third aspect of this disclosure provides a catalyst comprising an auxiliary agent and an optional main catalyst, wherein the auxiliary agent is the one provided in the first aspect of this disclosure.

[0062] According to this disclosure, the main catalyst can be selected according to actual needs and can be a catalytic cracking catalyst and / or catalytic pyrolysis catalyst well known to those skilled in the art.

[0063] The fourth aspect of this disclosure provides a method for the catalytic conversion of hydrocarbon oil, the method comprising: contacting the hydrocarbon oil with an additive provided in the first aspect of this disclosure or a catalyst provided in the third aspect of this disclosure to react.

[0064] In one specific embodiment of this disclosure, the reaction conditions include: a temperature of 300-700°C, preferably 400-600°C, more preferably 400-550°C, and a weight hourly space velocity of 4-120 h⁻¹. -1 Preferably 4-80 hours -1 More preferably 8-16 hours -1 The additive-to-oil weight ratio is 1-20, preferably 2-10, and more preferably 4-8. The additives provided in this disclosure can be used in various existing catalytic cracking reactors, such as fixed-bed reactors, fluidized-bed reactors, riser reactors, and multi-reaction-zone reactors.

[0065] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.

[0066] When evaluating the performance of the additives disclosed herein in catalytic cracking reactions, an ACE apparatus is used for evaluation.

[0067] For details of the RIPP standard method described in this disclosure, please refer to "Analytical Methods in Petrochemical Industry", edited by Yang Cuiding et al., 1990 edition.

[0068] Nitrogen adsorption method (RIPP151-90) was used to determine the pore volume.

[0069] The properties of some of the raw materials used in the examples and comparative examples are as follows:

[0070] Boehmite is an industrial product manufactured by Shandong Aluminum Company, with a solid content of 60% by weight.

[0071] The aluminum sol is an industrial product produced by Sinopec Catalyst Qilu Branch, with an Al2O3 content of 21.5% by weight.

[0072] Kaolin is a special kaolin for additives produced by Suzhou Kaolin Company, with a solid content of 78% by weight.

[0073] FeCl3·6H2O: Chemically pure, 99% purity, Xilong Scientific Co., Ltd.

[0074] Hydrochloric acid: chemically pure, concentration 36-38% by weight, produced by Beijing Chemical Plant.

[0075] MPZ molecular sieve: an industrial product produced by Sinopec Catalysts Qilu Branch, with a P2O5 content of 7.25% by weight, a Fe2O3 content of 1.95% by weight, and a crystallinity of 72%.

[0076] Phosphorus-containing β-molecular sieve: H-β molecular sieve was impregnated with a 0.2 mol / L ammonium dihydrogen phosphate solution by stirring for two hours, dried at 120℃ for 10 hours, and calcined at 500℃ for 3 hours to obtain phosphorus-modified β-molecular sieve P-β, in which the P2O5 content was 6.23% by mass and the crystallinity was 78%.

[0077] SLA is a catalytic cracking catalyst produced by Sinopec Catalyst Qilu Branch.

[0078] The average particle size of the phosphorus aluminum binder in this disclosure was determined by transmission electron microscopy.

[0079] Preparation Examples 1-4 are examples of the preparation of the phosphorus aluminum binder disclosed herein.

[0080] Preparation Example 1

[0081] (1) Mix 0.56 kg of anhydrous aluminum sulfate with 0.25 kg of decationized water and 0.05 kg of oxalic acid, stir, and heat to 70 °C and slurry for 30 minutes to obtain an alumina precursor solution with a solid content of 39% by weight.

[0082] (2) 0.56 kg of ammonium dihydrogen phosphate was added to the alumina precursor solution prepared in step (1) while maintaining a temperature of 45°C and stirring. The mixture was then reacted at 45°C for 45 minutes until it became a transparent colloid, yielding aluminum-phosphorus binder P-1. The material ratios are shown in Table 1, and the NMR spectrum of the aluminum-phosphorus binder is shown in [Table 1]. Figure 1 .

[0083] Preparation Examples 2-4

[0084] The phosphorus aluminum binder was prepared using the same method as in Preparation Example 1, except that the raw materials used and their amounts were different. The specific material ratios are shown in Table 1.

[0085] Preparation of Comparative Example 1

[0086] The phosphorus aluminum inorganic binder was prepared according to the method provided in patent ZL201110180891.X. The specific method is as follows:

[0087] At room temperature (25℃), 0.98 kg of pseudoboehmite (containing 0.6 kg of Al2O3), 0.2 kg of tartar (0.16 kg dry basis), and 0.44 kg of decationized water were mixed and slurried for 30 minutes. While stirring, 2.01 kg of concentrated phosphoric acid (85% by mass) was added to the slurry at a rate of 0.03 kg phosphoric acid / min / kg alumina source. The temperature was raised to 70℃, and the reaction was carried out at this temperature for 45 minutes to obtain the phosphorus-aluminum inorganic binder DPAL-1. The NMR spectrum is shown below. Figure 1 .

[0088] Depend on Figure 1 It can be seen that, in the 31P NMR spectrum of the aluminum phosphorus binder, the area of ​​the resonance signal peak with a chemical shift of 12±2 ppm is defined as QP0. 2 The peak area of ​​the resonance signal with a chemical shift of 0 ± 2 ppm is defined as QP0. 0 Under the same phosphorus-aluminum ratio, the QP0 of the phosphorus-aluminum binder prepared in Example 1 was... 2 / QP0 0 Compared with the QP0 of the phosphorus aluminum inorganic binder prepared in Comparative Example 1 2 / QP0 0 A higher value indicates a higher degree of polymerization.

[0089] Table 1

[0090]

[0091]

[0092] Examples 1-6 are preparation examples of the additives disclosed herein.

[0093] Example 1

[0094] S1. Take P-β molecular sieve and MPZ molecular sieve, add decationized water and slurry for 10 min, then slurry for 120 min to obtain molecular sieve slurry; add kaolin, alumina sol, FeCl3·6H2O and pseudoboehmite to decationized water and slurry for 20 min, add molecular sieve slurry while stirring, add hydrochloric acid to adjust the pH of the slurry to 3.0, and then continue slurrying for 45 min to obtain the first slurry;

[0095] S2. Add the phosphorus aluminum binder P-1 to the first slurry prepared in step S1, stir for 5 minutes, spray dry the slurry, and calcine the microspheres at 500℃ for 2 hours to obtain the additive CAT-1. The ratio is shown in Table 2.

[0096] Examples 2-6

[0097] The additives were prepared using the same method as in Example 1, except that the raw materials and their amounts were different. The specific proportions are shown in Table 2.

[0098] Comparative Example 1

[0099] MPZ molecular sieve, kaolin, FeCl3·6H2O and pseudoboehmite were added, along with decationized water and aluminum sol, and the mixture was stirred for 120 minutes. Hydrochloric acid was added to adjust the pH of the slurry to 3.0, and stirring was continued for 45 minutes. Then, phosphorus aluminum inorganic binder (DPAL-1) was added, and the mixture was stirred for 5 minutes. The resulting slurry was spray-dried to obtain microspheres. The microspheres were calcined at 500℃ for 1 hour to obtain the additive DCAT-1. The proportions are shown in Table 2.

[0100] Comparative Example 2

[0101] The additive DCAT-2 was prepared using the same method as in Example 1, except that the aluminum phosphorus inorganic binder DPAL-1 was used instead of the aluminum phosphorus binder P-1. The material ratio and parameters of the additive are shown in Table 2.

[0102] Comparative Example 3

[0103] The auxiliary agent DCAT-3 was prepared using the same method as in Example 1, except that, as shown in Table 2, an equal amount of MPZ molecular sieve was used instead of P-β molecular sieve in step S1.

[0104] Table 2

[0105]

[0106] Test case

[0107] The following examples use a fixed fluidized bed reactor to illustrate the cracking reaction effect of the cracking catalyst provided in this disclosure.

[0108] The catalytic cracking catalyst SLA, along with 30g of CAT-1~6 and DCAT-1~3, were aged for 17 hours at 800℃ under a 100% steam atmosphere. Different amounts of the aged catalyst were mixed with SLA (main properties shown in Table 3), and the catalyst mixtures were loaded into a reactor of a small fixed fluidized bed reactor to catalytically crack the feedstock oil shown in Table 4. Table 5 shows the reaction conditions and results.

[0109] Table 3. Main properties of SLA catalyst for catalytic cracking

[0110]

[0111] Table 4 Evaluation of the properties of the feedstock oil

[0112]

[0113]

[0114] Table 5 Evaluation Results

[0115]

[0116]

[0117]

[0118] As shown in Table 5, compared with the reference catalyst, the additives provided in this disclosure can effectively increase the content of propylene and butene in catalytic cracking liquefied petroleum gas, increase the olefin content in LPG, reduce the sum of the yields of diesel and slurry oil, and increase the sum of the yields of gasoline and LPG.

[0119] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0120] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0121] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A low-carbon olefin additive for promoting heavy oil conversion, wherein, based on the dry weight of the additive, the additive contains 25-75% by weight of molecular sieve, 0.5-8% by weight of metal component (calculated as metal oxide), 3-40% by weight of phosphorus aluminum binder (calculated as oxide), 1-25% by weight of other inorganic binder (calculated as oxide), and 0-30% by weight of clay; in, The molecular sieve contains MFI structure molecular sieve and BEA structure molecular sieve, the molecular sieve contains a first phosphorus component, the phosphorus aluminum binder contains a second phosphorus component, the total content of the first phosphorus component and the second phosphorus component in the additive, calculated as P2O5, is 10-35% by weight; the pore volume of the additive, as determined by the BJH method, is greater than 0.12 mL / g. Based on the total weight of the phosphorus aluminum binder, the phosphorus aluminum binder contains 3-15% by weight of Al2O3, 15-40% by weight of P2O5, and 0.1-10% by weight of stabilizer; the P / Al weight ratio of the phosphorus aluminum binder is 1.6-6, the pH value is 0.5-2.5, and the QPO is [not specified]. 2 / QP0 0 The range is 1-5, where QP0 2 Indicates by 31 P-NMR spectroscopy analysis of the phosphorus aluminum binder yielded a resonance signal peak area with a chemical shift of 12 ± 2 ppm, QP0. 0 The area of ​​the resonance signal peak with a chemical shift of 0±2ppm is indicated, and the average particle size of the phosphorus aluminum binder is 10-30nm; the stabilizer is selected from one or more of acetic acid, glycolic acid, oxalic acid, malonic acid, malic acid, tartaric acid, succinic acid, adipic acid, maleic acid, itaconic acid and citric acid.

2. The adjuvant according to claim 1, wherein, The phosphorus-aluminum binder contains 3-12 wt% Al₂O₃, 15-32 wt% P₂O₅, and 0.5-5 wt% stabilizer; the P / Al weight ratio of the phosphorus-aluminum binder is 1.7-5.8, the pH value is 0.5-2.5, and the QPO is [not specified]. 2 / QP0 0 The solid content of the aluminum phosphate binder is 15-50% by weight.

3. The adjuvant according to claim 1, wherein, Based on the dry weight of the additives, the content of the molecular sieve is 30-65% by weight, the content of the metal component is 1-5% by weight, the content of the phosphorus aluminum binder (calculated as oxides) is 8-32% by weight, the content of the other inorganic binders (calculated as oxides) is 2-20% by weight, and the content of the clay is 1-25% by weight.

4. The adjuvant according to claim 1, wherein, The other inorganic binders are selected from one or more of boehmite, alumina, aluminum sol, silica-alumina sol, and silica sol. The clay is selected from one or more of kaolin, sepiolite, attapulgite, rettoite, montmorillonite, and diatomite. The molecular sieve is an MFI structure molecular sieve and a BEA structure molecular sieve; the MFI molecular sieve and the BEA molecular sieve are each independently selected from one or more of hydrogen-type molecular sieves, phosphorus-containing molecular sieves and transition metal-containing molecular sieves; The metal in the metal component is selected from at least one of Group VIII metals.

5. The adjuvant according to claim 4, wherein, The MFI structured molecular sieve is a hierarchical porous ZSM-5 molecular sieve. The silica-alumina ratio of the hierarchical porous ZSM-5 molecular sieve is 20-70. The pore volume of pores with a diameter of 2-50 nm accounts for 40-70% of the total pore volume. The pore volume of pores with a diameter of 2-20 nm accounts for more than 85% of the total mesopore volume. The pore volume measured by the BJH method is greater than 0.25 mL / g, and the micropore volume is greater than 0.1 cc / g.

6. The adjuvant according to claim 4, wherein, The BEA-structured molecular sieve is a β-molecular sieve, and the microporous specific surface area of ​​the β-molecular sieve is 450-500 m². 2 / gram, the mesopore volume of the β molecular sieve accounts for 35-60% of the total pore volume; the strong acid content of the molecular sieve accounts for 25-55% of the total acid content, and the ratio of Brønsted acid content to Lewis acid content is 35-75.

7. The adjuvant according to claim 4, wherein, The weight ratio of the BEA structure molecular sieve to the MFI structure molecular sieve in the molecular sieve is (0.01-100):

1.

8. The adjuvant according to claim 4, wherein, The metal component is one or more of Fe, Co and Ni.

9. A method for preparing the low-carbon olefin auxiliary agent according to any one of claims 1-8, the method comprising: S1. Mix the molecular sieve, the other inorganic binder, the clay, the metal source and water to form a slurry, and control the pH value of the slurry to be greater than 2.5 to obtain the first slurry. S2. After mixing the first slurry with the phosphorus aluminum binder, spray drying and calcination are carried out to obtain the additive.

10. The method according to claim 9, wherein, The phosphorus aluminum binder is prepared by a method comprising the following steps: (1) Under stirring conditions at 50-95℃, aluminum source, water and stabilizer are mixed to obtain an alumina precursor solution with a solid content of 5-40% by weight; (2) Under the conditions of temperature and stirring at 25-70℃, the alumina precursor solution is mixed and reacted with phosphate to obtain the phosphorus aluminum binder.

11. The method according to claim 10, wherein, The aluminum source is selected from one or more of aluminum nitrate, aluminum sulfate, and aluminum chloride; The phosphate is diamine hydrogen phosphate and / or ammonium dihydrogen phosphate; The stabilizer is selected from acetic acid or citric acid; The metal source is one or more of iron salts, cobalt salts, and nickel salts.

12. The method according to claim 11, wherein, The metal source is FeCl3·6H2O.

13. A catalyst comprising an auxiliary agent and an optional main catalyst, wherein the auxiliary agent is the auxiliary agent according to any one of claims 1-8.

14. A method for catalytic conversion of hydrocarbon oil, the method comprising: The hydrocarbon oil is reacted with the additives described in any one of claims 1-8 or the catalyst described in claim 13.

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