Protective agent support component for catalytic oil slurry hydrogenation, support and method for preparing the same

Abstract

The application discloses a kind of for catalytic cracking oil slurry hydrogenation protective agent carrier component, carrier and its preparation method.The carrier component is alumina dry gel, the property after calcination includes: the most probable pore size is 40-100nm, the pore volume of (the most probable pore size-30) nm to (the most probable pore size+30) nm channel accounts for more than 75% of total pore volume.The preparation method of the alumina dry gel includes the following steps: a) first aluminum source, second aluminum source and third aluminum source are mixed with water to obtain slurry, then the slurry is grinded;B) the slurry obtained in step a) is added to clean water and stirred;C) modifier, pH regulator and optional dispersant are added to the material obtained in step b), to obtain mixed slurry, then the mixed slurry is hydrothermally treated;D) the material obtained in step c) is dried to obtain the carrier component, i.e., alumina dry gel.The hydrogenation protective agent carrier has suitable pore size, suitable macropore pore volume ratio, which can eliminate the diffusion resistance of macromolecules on the catalyst surface during catalytic cracking oil slurry hydrogenation process, and is beneficial to the progress of hydrogenation reaction.

Description

Technical Field

[0001] This invention belongs to the field of hydrogenation technology, and specifically relates to a protective agent carrier component, carrier, and preparation method for catalytic slurry hydrogenation. Background Technology

[0002] With the continuous deterioration and increasing heaviness of petroleum resources, the market demand for diversified and lightweight petrochemical products is growing. Processing low-quality, heavy crude oil has become a significant challenge for refineries worldwide. Catalytic cracking technology is one of the three main processes for deep processing of heavy oil and a key technology for lightweighting feedstocks, exhibiting strong adaptability to various feedstocks. Currently, some catalytic cracking units can directly process atmospheric residue or blend with some vacuum residue, leading to problems such as a deterioration in the distribution of catalytic cracking products. To increase unit throughput, reduce energy consumption, and increase lightweight products, external slurry loading is a good solution, but this generates a large amount of catalytic cracking slurry as a byproduct. As a low-value-added product of the catalytic cracking process, catalytic cracking slurry is characterized by high density, high carbon residue, high viscosity, and high aromatic content, and contains residual catalyst particles and coke, making its processing and utilization difficult. Therefore, how to process and utilize catalytic cracking slurry has become a critical issue that refineries urgently need to address.

[0003] Catalytic cracking slurry oil, rich in aromatics, is an ideal raw material for the preparation of high-end carbon-based materials such as needle coke. Needle coke is characterized by high crystallinity, high strength, high graphitization, low thermal expansion, and low ablation, and is mainly used in ultra-high power graphite electrodes and lithium-ion battery anode materials. As a raw material for needle coke production, catalytic cracking slurry oil typically requires low sulfur, low nitrogen, low ash content, and high aromatic content, especially high levels of tricyclic and tetracyclic aromatics. However, catalytic cracking slurry oil has high density, high carbon residue, high viscosity, high aromatic content, and contains residual catalyst particles and coke, making it difficult to utilize. Currently, high-quality low-sulfur slurry oil resources are very scarce, while inferior slurry oil has a high sulfur content (1.0 wt%–2.0 wt%). Needle coke products have strict requirements for sulfur content (≤0.5 wt%), and processing with conventional residue hydrotreating catalysts results in excessive aromatic loss. Currently, there is limited research on hydrogenation catalysts specifically for catalytic cracking slurry oil. Therefore, developing a catalyst suitable for hydrogenation of catalytic cracking slurry oil is of great significance.

[0004] CN103013567A discloses a method for producing needle coke feedstock from catalytic cracking slurry. This method includes a protected zone and a hydrotreating reaction zone. The protected zone is filled with an adsorbent capable of adsorbing catalytic cracking catalyst powder. The hydrotreating reaction zone is filled sequentially with a hydroprotective agent, a hydrodemetallizing agent, and a hydrodesulfurizing agent according to the flow direction of the reaction stream. The catalytic cracking slurry first enters the protected zone, adsorbing most of the catalytic cracking catalyst powder, and then mixes with hydrogen into a heater. After heating, it enters the hydrotreating reaction zone for hydrotreating. The hydroprotective agent is Raschig ring-shaped and is a conventional residue hydroprotective agent. However, for catalytic cracking slurry feedstock, the pore volume of the hydroprotective agent in the above method is relatively small. During the hydrotreating reaction, continuous coke deposition easily causes pore blockage, covering of active sites, and rapid catalyst activity decay, ultimately leading to unit shutdown.

[0005] Because the feedstock for catalytic cracking slurry oil differs from that of conventional residue oil, existing conventional residue oil hydrotreating catalysts still present the aforementioned problems when used with catalytic cracking slurry oil feedstock. Therefore, there is an urgent need to develop suitable catalysts and supports for catalytic cracking slurry oil hydrotreating. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a protective agent carrier component, carrier, and preparation method for catalytic cracking slurry hydrotreating. This hydrotreating protective agent carrier has a suitable pore size and a suitable proportion of large-pore volume, which can eliminate the diffusion resistance of macromolecules adsorbing and reacting on the catalyst surface during catalytic cracking slurry hydrotreating, thus facilitating the hydrotreating reaction.

[0007] The hydrotreating protectant for catalytic cracking slurry hydrotreating is placed in the upper layer of the catalytic cracking slurry hydrotreating reactor, receiving the separated and deconsolidated catalytic cracking slurry. The deconsolidated catalytic cracking slurry has a high content of gums and asphaltenes (4.0%–15.0%). Asphaltenes molecules are mainly composed of 5 to 7 lamellar fused aromatic rings with a size of 12–16 angstroms (1.2–1.6 nm), and these molecules are prone to aggregation. The inventors discovered that developing a hydrotreating protectant with suitable large pore size and distribution can eliminate the diffusion resistance of large asphaltenes during adsorption and reaction on the catalyst surface, thus facilitating the hydrotreating reaction. Simultaneously, the slurry contains a large amount of coking material; the hydrotreating protectant, with its large pore size, can not only accommodate more coke deposits but also ensure that many active sites remain uncovered by coke even after prolonged operation. This plays a crucial role in protecting the performance of the downstream catalyst from the influence of coke and other impurities, thereby guaranteeing the long-term operation of the unit.

[0008] The first aspect of the present invention provides a hydrotreating protectant carrier component for hydrotreating catalytic cracking slurry, wherein the carrier component is alumina dry gel, and the properties after calcination include: a most probable pore size of 40-100 nm, preferably 50-70 nm, and pores from (most probable pore size - 30) nm to (most probable pore size + 30) nm occupying more than 75% of the total pore volume, preferably 75%-90%.

[0009] In this invention, the pore distribution of the alumina dry adhesive after calcination has a single peak from (most probable pore diameter - 30) nm to (most probable pore diameter + 30) nm, with a peak width of at least 60 nm.

[0010] In this invention, the alumina dry adhesive, after calcination, has the following properties: a pore volume of 0.95–1.35 cm³. 3 / g, preferably 1.05~1.30cm 3 / g.

[0011] In this invention, the alumina dry adhesive, after calcination, has the following properties: a specific surface area of ​​140–220 m². 2 / g, preferably 150-200m 2 / g.

[0012] In this invention, the calcination conditions for the alumina dry adhesive are as follows: calcination temperature is 500-800℃, calcination time is 3-12 hours, and the calcination atmosphere is air.

[0013] The second aspect of the present invention provides a hydroprotectant support for hydrotreating catalytic cracking slurry, wherein the support is an alumina-based support with a most probable pore size of 40-100 nm, preferably 50-70 nm, and the pore volume occupied by channels from (most probable pore size - 30) nm to (most probable pore size + 30) nm accounts for more than 75% of the total pore volume, preferably 75%-90%.

[0014] In this invention, the pore volume of the carrier is 1.00–1.40 cm³. 3 / g, preferably 1.10~1.30cm 3 / g.

[0015] In this invention, the specific surface area of ​​the carrier is 120–180 m². 2 / g, preferably 130-170m 2 / g.

[0016] In this invention, the carrier is preferably shaped like a four-leaf impeller or a four-leaf clover.

[0017] A third aspect of this invention provides a method for preparing the above-mentioned carrier component, namely alumina dry adhesive, comprising the following steps:

[0018] a) The first aluminum source, the second aluminum source and the third aluminum source are mixed with water to obtain a slurry, and then the slurry is ground.

[0019] b) Add purified water to the slurry obtained in step a) and stir;

[0020] c) Add modifier, pH adjuster and optional dispersant to the material obtained in step b) to obtain a mixed slurry, and then perform hydrothermal treatment on the mixed slurry;

[0021] d) The material obtained in step c) is dried to obtain the carrier component, namely alumina dry adhesive.

[0022] In the method of the present invention, in step a), the first aluminum source is aluminum oxide trihydrate.

[0023] In the method of this invention, in step a), the second aluminum source is alumina dry adhesive with a water content of less than 35% by mass fraction. The alumina dry adhesive can be a product of dehydration of alumina hydrate; it can be completely dehydrated alumina or partially dehydrated alumina, such as monohydrated alumina.

[0024] In the method of this invention, in step a), the third aluminum source is an aluminum-containing salt compound, which can be an acidic aluminum salt, a basic aluminate, and / or aluminate. The third aluminum source can be selected from at least one of aluminum nitrate, aluminum chloride, aluminum sulfate, sodium aluminate, etc.

[0025] In the method of the present invention, in step a), the mass ratio of the first aluminum source, the second aluminum source and the third aluminum source is 30-66:33-60:1-10.

[0026] In the method of the present invention, in step a), the amount of water added is 100% to 150% of the total mass of the first aluminum source, the second aluminum source and the third aluminum source.

[0027] In the method of the present invention, in step a), the slurry is ground until the particle size in the slurry is 4 to 20 μm, calculated as the median particle size D50.

[0028] In the method of the present invention, in step b), the slurry obtained in step a) is mixed with purified water (preferably deionized water) so that the total mass of the first aluminum source, the second aluminum source and the third aluminum source in the slurry is 10% to 20%.

[0029] In the method of the present invention, in step c), the pH adjuster can be an alkaline substance (such as at least one of sodium hydroxide, ammonia, sodium bicarbonate, ammonium carbonate, etc.) or an acidic substance (such as at least one of acetic acid, citric acid, nitric acid, etc.). The added pH adjuster is adjusted according to the properties of the slurry to control the pH of the mixed slurry to be 8.5 to 12.0.

[0030] In the method of this invention, in step c), the dispersant is selected from at least one of hydrophilic dispersants. The dispersant can be a nonionic surfactant with an HLB value (Hydrophile-Lipophile Balance Number) of 10 to 20. The amount of dispersant added is less than 10% of the mass of the material obtained in step b), preferably 0.01% to 10%. The nonionic surfactant dispersant is preferably at least one of Tween-80, lauryl alcohol polyoxyethylene ether, and methyl glucose polyoxyethylene ether. The modifier is preferably at least one of sodium hexametaphosphate, sodium tripolyphosphate, disodium ethylenediaminetetraacetate, sodium gluconate, and sodium tartrate. The amount of the modifier added is 0.01% to 6% of the mass of the material obtained in step b), for example, but not limited to: 0.1%, 0.2%, 0.5%, 0.6%, 0.8%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, etc.

[0031] In the method of the present invention, in step c), the hydrothermal treatment conditions are as follows: temperature is 220-280℃, and time is 5-12 hours.

[0032] In the method of this invention, in step d), before drying, the material obtained in step c) can be subjected to steps such as filtration and washing. Conventional filtration and washing methods are sufficient. The drying conditions are as follows: drying temperature is 100–180℃, and drying time is 4–10 hours.

[0033] A fourth aspect of the present invention provides a method for preparing the above-mentioned catalyst support, comprising the following steps:

[0034] The above-mentioned alumina dry adhesive is mixed with a binder, shaped, dried, and calcined to obtain the carrier.

[0035] In the method of this invention, the binder is selected from at least one of inorganic acid, organic acid, cellulose, and resin, wherein the inorganic acid can be nitric acid, and the organic acid is selected from at least one of acetic acid, citric acid, and tartaric acid. The cellulose is at least one of hydroxypropyl cellulose or methylcellulose, and the resin is at least one of phenolic resin or ethylene-vinyl acetate resin. The amount of binder added is 0.1% to 10% of the mass of the alumina dry adhesive.

[0036] In the method of this invention, molding aids, such as extrusion aids, may be added depending on the molding process. The extrusion aid is selected from guar gum powder; the amount of extrusion aid added is 0.5% to 6.0% of the mass of the alumina dry adhesive.

[0037] In this invention, no pore-forming material, such as a pore expander, is required. The pore-forming material refers to the material added during the carrier preparation process. During the molding process, the pore expander molecules are encapsulated by alumina powder particles. After high-temperature calcination, the pore expander molecules are oxidized or undergo other chemical reactions to generate gas and escape, leaving the previously occupied space, thus forming a material with large pores, such as carbon black or starch.

[0038] In the method of the present invention, the formed shape can be a four-leaf wheel or a four-leaf clover shape.

[0039] In the method of this invention, the drying conditions after molding are as follows: drying temperature is 100–180℃, and drying time is 4–12 hours; the calcination conditions after molding are as follows: calcination temperature is 500–800℃, and calcination time is 3–12 hours. The calcination atmosphere can be an oxygen-containing gas, such as air.

[0040] In this invention, the carrier is loaded with a small amount of hydrogenation active metal to prepare a hydrogenation protective agent, which is particularly suitable for filling the upper layer of the catalytic cracking slurry hydrogenation unit. It is mainly used as a hydrogenation protective agent to protect the downstream main hydrogenation catalyst and provide a guarantee for the long-term operation of the catalytic cracking slurry hydrogenation unit.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. In existing technologies, catalytic cracking slurry and residue oil are similar, both containing gums and asphaltenes. However, catalytic cracking slurry and residue oil have different properties. Catalytic cracking slurry has a lower metal content, and catalyst deactivation is mainly due to coke deposition. The operating cycles of catalytic cracking slurry hydrotreating units and residue oil hydrotreating units differ; catalytic cracking slurry hydrotreating units generally operate for two years, while residue oil hydrotreating units operate for about one year. Under different feedstocks and operating modes, catalytic cracking slurry hydrotreating units require hydrotreating protectants with as many large pores as possible to accommodate more coke deposits, protecting downstream catalysts and ensuring long-term unit operation. This invention provides a hydrotreating protectant carrier suitable for catalytic cracking slurry hydrotreating. The carrier has a large pore size; mercury porosimetry shows that the probable pore size of the carrier is 40–100 nm, and the pore size distribution is relatively concentrated, with the pore volume in the range of (probable pore size - 30) nm to (probable pore size + 30) nm accounting for more than 75% of the total pore volume of the carrier. The hydrogenation protective agent carrier of this invention has a suitable large pore size and a suitable pore volume ratio, which can eliminate the diffusion resistance of macromolecules adsorbing and reacting on the catalyst surface during the hydrogenation of catalytic cracking slurry. At the same time, it can accommodate more carbon deposits, which is beneficial to the long-term operation of the hydrogenation unit.

[0043] 2. In the preparation of the hydrogenation protective agent carrier of the present invention, three different aluminum sources are used, the pH value is controlled, a modifier is added, and then hydrothermal treatment is carried out. During the hydrothermal treatment, different aluminum sources form different precursor particles, which then undergo a rehydration reaction. The resulting alumina dry gel does not require the addition of additional pore-forming materials such as pore expanders. It can be obtained by calcining at a relatively low temperature (below 800℃) to produce the hydrogenation protective agent carrier of the present invention with a suitable large pore size and a suitable large pore volume ratio.

[0044] Detailed Implementation Methods

[0045] The technical solution and effects of the present invention will be further illustrated below through embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0046] Unless otherwise specified, the experimental methods used in the following examples are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following examples were purchased from conventional biochemical reagent stores.

[0047] The pore volume and pore size of the alumina support components, alumina supports and catalysts prepared in this invention (including the embodiments), as well as the alumina support components, alumina supports and catalysts prepared in Comparative Examples 1 and 4, and conventional residue hydroprotective agent supports and catalysts, were all measured by mercury porosimetry using a MicroActive AutoPore V 9600 instrument.

[0048] In this invention, the pore volume and pore size of the alumina support components, alumina support and catalyst involved in Comparative Examples 2, 3 and 5 were obtained by low-temperature liquid nitrogen adsorption method using an ASAP2420 pore structure analyzer from Micron Technology, Inc.

[0049] The specific surface areas of the alumina support components, alumina support and catalyst prepared in this invention (including the examples) and the alumina support components, alumina support and catalyst prepared in the comparative examples were obtained by low-temperature liquid nitrogen adsorption method using an ASAP2420 pore structure analyzer from Micron Technology, USA.

[0050] Example 1

[0051] Take 100g of alumina trihydrate, 100g of alumina monohydrate, and 15g of sodium aluminate, add 300g of purified water, and grind using a ball mill at 500rpm for 1 hour. The particle size (D50) of the slurry is 6.05μm. Add another 1000g of purified water to the ground slurry and stir. Then add 2g of acetic acid, 5g of sodium hexametaphosphate, and 10g of Tween-80, bringing the pH of the slurry to 8.93. Transfer the stirred slurry to an autoclave for hydrothermal treatment at 260℃ for 8 hours. Filter and wash the material obtained after hydrothermal treatment, and dry it at 120℃ for 5 hours to obtain alumina dry gel GA.

[0052] Take 100g of the prepared alumina dry adhesive, add 1g of guar gum powder, 2g of methylcellulose, 0.5g of acetic acid, and 130g of purified water, knead and shape into a four-leaf wheel-shaped carrier. After shaping, dry at 120℃ for 4 hours and calcine at 700℃ for 4 hours to obtain hydrogenated protective agent carrier A.

[0053] Example 2

[0054] Compared to Example 1, the difference lies in the preparation process of the alumina dry adhesive: 100g of alumina trihydrate, 85g of alumina monohydrate, and 15g of sodium aluminate were added to 300g of purified water and ground using a ball mill. This yielded alumina dry adhesive GB and hydrogenated protective agent carrier B.

[0055] Example 3

[0056] Compared to Example 1, the difference lies in the preparation process of the alumina dry adhesive. 100g of alumina trihydrate, 100g of alumina monohydrate, and 10g of aluminum sulfate were added to 300g of purified water and ground using a ball mill. Then, 1000g of purified water was added to the ground slurry, stirred, followed by the addition of 8g of sodium hydroxide, 5g of sodium hexametaphosphate, and 10g of Tween-80. The pH of the slurry was 9.14. Alumina dry adhesive GC and hydrogenation protective agent carrier C were thus obtained.

[0057] Example 4

[0058] Compared to Example 1, the difference lies in the preparation process of the alumina dry adhesive: 900 grams of purified water are added to the ground slurry and stirred, followed by 2 grams of acetic acid and 9 grams of sodium hexametaphosphate. This yields alumina dry adhesive GD and a hydrogenation protective agent carrier D.

[0059] Example 5

[0060] Compared to Example 1, the difference lies in that the slurry after stirring during the preparation of the alumina dry adhesive is transferred to an autoclave for hydrothermal treatment at a temperature of 270°C for 7 hours. This yields alumina dry adhesive GE and a hydrogenated protective agent carrier E.

[0061] Example 6

[0062] Compared to Example 1, the difference lies in that the prepared alumina dry adhesive is kneaded and molded, then dried at 120°C for 4 hours and calcined at 750°C for 4 hours. This yields alumina dry adhesive GF and a hydrogenation protective agent carrier F.

[0063] Comparative Example 1

[0064] Compared to Example 1, the difference lies in the use of commercially available macroporous pseudo-thin-water alumina (DGA) for kneading and molding with alumina dry adhesive. After molding, the alumina was dried at 120°C for 4 hours and then calcined at 900°C for 4 hours to obtain a comparative hydrogenation protective agent carrier DA.

[0065] Comparative Example 2

[0066] Compared to Example 1, the difference lies in that 100 grams of alumina trihydrate was added to 1000 grams of purified water and transferred to an autoclave for hydrothermal treatment at 260°C for 8 hours. The material obtained after hydrothermal treatment was filtered, washed, and dried at 120°C for 5 hours to obtain alumina dry gel. Comparative alumina dry gel DGB and comparative hydrogenated protective agent carrier DB were prepared.

[0067] Comparative Example 3

[0068] Compared to Example 1, the difference lies in taking 100 grams of alumina trihydrate and 100 grams of alumina monohydrate, adding 300 grams of purified water, and grinding them using a ball mill. This yielded comparative alumina dry gel DGC and comparative hydrogenated protective agent carrier DC.

[0069] Comparative Example 4

[0070] Compared to Example 1, the difference is that 1000g of purified water was added to the ground slurry and stirred, followed by 2g of acetic acid and 10g of Tween-80. This yielded comparative alumina dry adhesive DGD and comparative hydrogenated protective agent carrier DD.

[0071] Comparative Example 5

[0072] Compared to Example 1, the difference lies in the addition of 1000g of purified water to the ground slurry, followed by stirring, and then the addition of 6g of nitric acid and 10g of Tween-80, resulting in a slurry pH of 1.93. This yielded comparative alumina dry gel DGE and comparative hydrogenated protective agent carrier DE.

[0073] Tables 1-4 list the carrier components and properties prepared in the above examples and comparative examples. The properties of the carrier components were measured after calcination at 600°C for 6 hours in an air atmosphere. In the pore distribution, there is a single peak from (most probable pore size - 30) nm to (most probable pore size + 30) nm, with a peak width of at least 60 nm.

[0074] Table 1 Properties of the catalyst support components obtained in each embodiment

[0075]

[0076] Table 2 Properties of catalyst support components obtained from each comparative example

[0077]

[0078]

[0079] Table 3 Pore properties of catalyst supports obtained in each example

[0080]

[0081] Table 4. Pore properties of catalyst supports obtained from each comparative example.

[0082]

[0083] Catalyst evaluation

[0084] The same amounts of active metals molybdenum and nickel were impregnated onto the supports prepared in Examples 1-6 and Comparative Examples 1-5, resulting in catalysts with a molybdenum oxide mass content of 4.5% and a nickel oxide mass content of 1%, respectively, yielding hydrotreating protectants CA, CB, CC, CD, CE, CF and DC-A, DC-B, DC-C, DC-D, DC-E. The prepared catalysts and a conventional residue hydrotreating protectant (brand name FZC-12A, four-bladed) were taken in equal volumes and loaded into the upper layer of the hydrotreating protectant position in the catalytic cracking slurry hydrotreating reactor. The other catalysts were the same (i.e., the catalysts loaded from top to bottom in a volume ratio of 2:2:6 were hydrotreating protectant, hydrodemetallization catalyst (brand name FZC-28), and hydrodesulfurization catalyst (brand name FZC-33B)). The catalyst sulfidation employs a wet sulfidation process, using dimethyl disulfide (DMDS) as the sulfiding agent. The sulfiding oil is straight-run diesel, with the sulfiding agent accounting for 1.5% of the diesel's mass. The sulfidation process involves constant temperature sulfidation at 230℃ for 8 hours, followed by constant temperature sulfidation at 320℃ for 8 hours. The feedstock is a full-fraction slurry oil with a sulfur content of 0.96 wt% and a density (20℃) of 1.096 g / cm³. 3 The (tri- and tetra-cyclic) aromatic hydrocarbon content was 57.2%. Process conditions: reaction pressure 6.0 MPa, reaction temperature 350℃, hydrogen-to-oil volume ratio 1000, liquid hourly space velocity 0.8 h⁻¹. -1 The results of hydrotreated catalytic cracking slurry obtained after 200 hours of operation are listed in Tables 5 and 6, and the results of hydrotreated catalytic cracking slurry obtained after 1500 hours of operation are listed in Tables 7 and 8.

[0085] Table 5 Evaluation results of catalysts in each example

[0086] Carrier number A B C D E F <![CDATA[Density of hydrogenation product (20℃), g / cm 3 > 1.052 1.050 1.053 1.052 1.055 1.054 Desulfurization rate, % 57.5 57.8 57.3 57.6 57.0 57.2 (Tricyclic + Tetracyclic) Aromatic Retention Rate, % 91.2 90.7 91.5 91.3 91.7 91.6

[0087] Table 6 Evaluation results of each comparative catalyst

[0088] Carrier number DA DB DC DD DE - <![CDATA[Density of hydrogenation product (20°C), g / cm 3 > 1.062 1.060 1.057 1.059 1.067 1.062 Desulfurization rate, % 54.9 55.2 55.8 55.4 52.5 54.8 (Tricyclic + Tetracyclic) Aromatic Retention Rate, % 92.4 92.2 91.7 92.0 93.3 92.5

[0089] Table 7 Evaluation results of catalysts in each example

[0090] Carrier number A B C D E F <![CDATA[Density of hydrogenation product (20°C), g / cm 3 > 1.055 1.053 1.056 1.055 1.058 1.057 Desulfurization rate, % 54.2 54.5 54.0 54.3 53.8 54.0 (Tricyclic + Tetracyclic) Aromatic Retention Rate, % 91.4 90.9 91.6 91.5 91.8 91.7

[0091] Table 8 Evaluation results of each comparative catalyst

[0092] Carrier number DA DB DC DD DE conventional <![CDATA[Density of hydrogenation product (20°C), g / cm 3 > 1.066 1.070 1.068 1.064 1.077 1.066 Desulfurization rate, % 48.8 46.9 48.4 49.2 42.7 49.1 (Tricyclic + Tetracyclic) Aromatic Retention Rate, % 92.9 93.3 93.1 92.5 94.4 92.8

[0093] In Table 5-8, the aromatic hydrocarbon retention rate is the percentage of the mass content of tricyclic and tetracyclic aromatic hydrocarbons in the hydrogenation product relative to the mass content of tricyclic and tetracyclic aromatic hydrocarbons in the feedstock. Tricyclic and tetracyclic aromatic hydrocarbons are ideal feedstock aromatic hydrocarbons for preparing high-end carbon-based materials such as needle coke; therefore, the aromatic hydrocarbon retention rate is the ideal aromatic hydrocarbon retention rate.

[0094] As can be seen from Tables 5-8, compared with the contrast agent and conventional hydrogenation protectant, the hydrogenation protectant prepared using the carrier of this invention, combined with the original catalyst gradation, results in a slower decay of catalyst activity, better desulfurization activity stability, and a greater retention rate for tricyclic and tetracyclic aromatic hydrocarbons.

[0095] The specific embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A hydroprotectant support for catalytic cracking slurry hydrotreating, wherein the support is an alumina-based support with a most probable pore size of 40-100 nm, and the pore volume occupied by channels from (most probable pore size - 30) nm to (most probable pore size + 30) nm accounts for more than 75% of the total pore volume; the properties of the support are as follows: pore volume of 1.00-1.40 cm³. 3 / g, specific surface area is 130~180m² 2 / g; The method for preparing the carrier includes the following steps: a) The first aluminum source, the second aluminum source and the third aluminum source are mixed with water to obtain a slurry, and then the slurry is ground. b) Add purified water to the slurry obtained in step a) and stir; c) Add modifier, pH adjuster and optional dispersant to the material obtained in step b) to obtain a mixed slurry, and then subject the mixed slurry to hydrothermal treatment; d) The material obtained in step c) is dried to obtain a carrier component; the carrier component is mixed with a binder, shaped, dried, and calcined to obtain the carrier; In step a), the first aluminum source is alumina trihydrate; the second aluminum source is alumina dry gel with a water content of less than 35% by mass fraction; and the third aluminum source is an aluminum-containing salt compound. In step c), the modifier is selected from at least one of sodium hexametaphosphate, sodium tripolyphosphate, disodium ethylenediaminetetraacetate, sodium gluconate, and sodium tartrate.

2. The carrier according to claim 1, characterized in that, The most probable pore size of the carrier is 50~70nm, and the pore volume occupied by the channels from (most probable pore size - 30)nm to (most probable pore size + 30)nm accounts for 75%~90% of the total pore volume.

3. The carrier according to claim 1, characterized in that, The pore volume of the carrier is 1.10~1.30 cm³. 3 / g; and / or, with a specific surface area of ​​130~170m² 2 / g.

4. The carrier according to claim 1, characterized in that, The carrier is in the shape of a four-leaf wheel or a four-leaf clover.

5. A method for preparing the carrier according to any one of claims 1-4, comprising the following steps: a) The first aluminum source, the second aluminum source and the third aluminum source are mixed with water to obtain a slurry, and then the slurry is ground. b) Add purified water to the slurry obtained in step a) and stir; c) Add modifier, pH adjuster and optional dispersant to the material obtained in step b) to obtain a mixed slurry, and then subject the mixed slurry to hydrothermal treatment; d) The material obtained in step c) is dried to obtain a carrier component; the carrier component is mixed with a binder, shaped, dried, and calcined to obtain the carrier; In step a), the first aluminum source is alumina trihydrate; the second aluminum source is alumina dry gel with a water content of less than 35% by mass fraction; and the third aluminum source is an aluminum-containing salt compound. In step c), the modifier is selected from at least one of sodium hexametaphosphate, sodium tripolyphosphate, disodium ethylenediaminetetraacetate, sodium gluconate, and sodium tartrate.

6. The preparation method according to claim 5, characterized in that, In step a), the second aluminum source is aluminum oxide monohydrate; the third aluminum source is at least one of aluminum nitrate, aluminum chloride, aluminum sulfate, and sodium aluminate.

7. The preparation method according to claim 5, characterized in that, In step a), the mass ratio of the first aluminum source, the second aluminum source, and the third aluminum source is 30~66:33~60:1~10.

8. The preparation method according to claim 5, characterized in that, In step a), the amount of water added is 100% to 150% of the total mass of the first aluminum source, the second aluminum source, and the third aluminum source.

9. The preparation method according to claim 5, characterized in that, In step a), the slurry is ground until the particle size in the slurry is 4~20µm, calculated as the median particle size D50.

10. The preparation method according to claim 5, characterized in that, In step b), the slurry obtained in step a) is mixed with purified water so that the total mass of the first aluminum source, the second aluminum source and the third aluminum source in the slurry is 10% to 20%.

11. The preparation method according to claim 5, characterized in that, In step c), the pH value of the mixed slurry is controlled to be 8.5~12.

0.

12. The preparation method according to claim 5, characterized in that, The amount of the dispersant added is less than 10% of the mass of the material obtained in step b), and / or the amount of the modifier added is 0.01% to 6% of the mass of the material obtained in step b).

13. The preparation method according to claim 12, characterized in that, The amount of dispersant added is 0.01% to 10% of the mass of the material obtained in step b).

14. The preparation method according to claim 5 or 11, characterized in that, In step c), the dispersant is a nonionic surfactant with an HLB value of 10-20.

15. The preparation method according to claim 14, characterized in that, In step c), the dispersant is at least one of Tween-80, lauryl alcohol polyoxyethylene ether, and methyl glucose polyoxyethylene ether.

16. The preparation method according to claim 5, characterized in that, In step c), the hydrothermal treatment conditions are as follows: temperature is 220~280℃, and time is 5~12 hours.

17. The preparation method according to claim 5, characterized in that, In step d), the drying conditions are as follows: the drying temperature is 100~180℃ and the drying time is 4~10 hours.

18. The preparation method according to claim 5, characterized in that, The binder is selected from at least one of inorganic acids, organic acids, cellulose, and resins; and / or, the amount of binder added is 0.1% to 10% of the mass of the carrier component.

19. The preparation method according to claim 18, characterized in that, The inorganic acid is nitric acid, the organic acid is selected from at least one of acetic acid, citric acid, and tartaric acid, the cellulose is at least one of hydroxypropyl cellulose or methylcellulose, and the resin is at least one of phenolic resin or ethylene-vinyl acetate resin.

20. The preparation method according to claim 5, characterized in that, The drying conditions after molding are as follows: drying temperature is 100~180℃, drying time is 4~12 hours; the calcination conditions after molding are as follows: calcination temperature is 500~800℃, calcination time is 3~12 hours.

21. The use of the support according to any one of claims 1-4 in a catalytic cracking slurry hydrotreating catalyst, characterized in that, The catalyst is a hydrogenation protectant.

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