Catalytic slurry oil hydrogenation protective agent and preparation method thereof

Abstract

The invention discloses a catalytic cracking oil slurry hydrogenation protective agent and a preparation method thereof. The hydrogenation protective agent comprises a carrier and hydrogenation active metal, an alumina carrier is adopted, the hydrogenation active metal comprises molybdenum oxide and cobalt oxide, and the alumina carrier has the following properties: the most probable pore diameter is 40-100 nm, preferably 50-70 nm, and the pore volume occupied by pore channels from (most probable pore diameter-30) nm to (most probable pore diameter + 30) nm accounts for more than 75% of the total pore volume. According to the hydrogenation protective agent, the alumina carrier with proper pore diameter and proper large-pore-diameter pore volume ratio is adopted, so that the diffusion resistance of macromolecules on the surface of a catalyst during adsorption and reaction in the catalytic cracking oil slurry hydrogenation process can be eliminated, and the hydrogenation reaction is facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogenation, and in particular relates to a catalytic oil slurry hydrogenation protective agent and a preparation method thereof. Background Art

[0002] As oil resources continue to degrade and become heavier, market demand for diversified and lighter petrochemical products is increasing. Processing low-quality, heavy crude oil has become a critical issue 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. It is also highly adaptable to feedstocks. Currently, some FCC units can directly process atmospheric residue or blend it with vacuum residue, leading to problems such as a poor distribution of FCC products. To increase unit throughput, reduce energy consumption, and increase the production of lighter products, slurry oil disposal is a promising solution. This, in turn, generates a large amount of FCC slurry oil as a byproduct. As a low-value-added product of the FCC process, FCC slurry oil exhibits high density, high carbon residue, high viscosity, and a high aromatic content. It also contains residual catalyst particles and coke, making it challenging to process and utilize. Therefore, how to process and utilize FCC slurry oil has become a critical issue that refineries urgently need to address.

[0003] Catalytic cracking oil, rich in aromatics, is an ideal raw material for producing high-end carbon-based materials such as needle coke. Needle coke boasts high crystallinity, high strength, high graphitization, low thermal expansion, and low ablation, making it primarily used in ultra-high-power graphite electrodes and lithium-ion battery anode materials. As a raw material for needle coke production, catalytic cracking oil is typically required to have low sulfur, low nitrogen, and low ash content, and high aromatic content, particularly high levels of tri- and tetra-ring aromatics. FCC 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 oil resources are extremely scarce, while lower-quality oils have high sulfur contents (1.0 wt% to 2.0 wt%). Needle coke products have strict sulfur content requirements (≤ 0.5 wt%), and processing with conventional residue oil hydrotreating catalysts results in excessive aromatic losses. At present, there are few studies on hydrogenation catalysts dedicated to catalytic cracking slurry oil. Therefore, it is of great significance to develop a catalyst suitable for hydrogenation of catalytic cracking slurry oil.

[0004] CN103013567A discloses a method for producing needle coke raw materials from catalytic cracking slurry. The method sets a protection zone and a hydrogenation reaction zone, wherein the protection zone is filled with an adsorbent that can adsorb catalytic cracking catalyst powder, and the hydrogenation reaction zone is filled with a hydrogenation protective agent, a hydrogenation demetallization agent and a hydrogenation desulfurization agent in sequence according to the flow direction of the reactant flow; the catalytic cracking slurry first enters the protection zone, adsorbs most of the catalytic cracking catalyst powder, and then is mixed with hydrogen and enters the heating furnace, and after heating, enters the hydrogenation reaction zone for hydrogenation treatment reaction. Among them, the hydrogenation protective agent is a Raschig ring, which is a conventional residual oil hydrogenation protective agent. However, for catalytic cracking slurry raw materials, the pore volume of the hydrogenation protective agent in the above method is relatively small. The continuous deposition of carbon deposits during the hydrogenation reaction process can easily cause pore blockage, active site coverage, and rapid catalyst activity decay, which ultimately leads to device shutdown.

[0005] Since catalytic cracking slurry oil feedstock is different from conventional residual oil feedstock, conventional residual oil hydrogenation series catalysts in the prior art still have the above-mentioned problems for catalytic cracking slurry oil feedstock. Therefore, it is urgent to develop catalysts suitable for catalytic cracking slurry oil hydrogenation. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention provides a catalytic cracking oil slurry hydrogenation protective agent and its preparation method. The hydrogenation protective agent has an appropriate pore size and a suitable large-pore volume ratio, which can eliminate the adsorption and diffusion resistance of macromolecules on the catalyst surface during the catalytic cracking oil slurry hydrogenation process, thereby facilitating the hydrogenation reaction.

[0007] The hydrogenation protectant used for hydrogenation of catalytic cracking slurry is installed in the upper layer of the catalytic cracking slurry hydrogenation reactor, receiving the catalytic cracking slurry after separation and desolidification. The desolidified catalytic cracking slurry contains a high content of colloids and asphaltenes (4.0% to 15.0%). Asphaltene molecules are mainly composed of 5 to 7 flaky, fused aromatic rings with a size of 12 to 16 angstroms (1.2 to 1.6 nm), and asphaltene molecules are prone to agglomeration. The inventors discovered that developing a hydrogenation protectant with a suitable large pore size and large pore size distribution can eliminate the diffusion resistance of asphaltene macromolecules during adsorption and reaction on the catalyst surface, thereby facilitating the hydrogenation reaction. Furthermore, given the high concentration of coking substances in the slurry, the hydrogenation protectant's large pore size not only accommodates more carbon deposits, but also leaves more active sites uncovered by carbon deposits even after extended operation. This plays a key role in protecting the performance of downstream catalysts from the effects of impurities such as carbon deposits, thereby ensuring the long-term operation of the device.

[0008] A first aspect of the present invention provides a catalytic cracking oil slurry hydrogenation protective agent, comprising a carrier and a hydrogenation active metal, wherein an alumina carrier is used, the hydrogenation active metal comprises molybdenum oxide and cobalt oxide, and the properties of the alumina carrier are as follows: the most probable pore diameter is 40 to 100 nm, preferably 50 to 70 nm, and the pore volume occupied by pores from (most probable pore diameter - 30) nm to (most probable pore diameter + 30) nm accounts for more than 75% of the total pore volume, preferably 75% to 90%.

[0009] In the present invention, in the alumina carrier, the range from (most probable pore diameter - 30) nm to (most probable pore diameter + 30) nm is a single peak, and the peak width is at least 60 nm.

[0010] In the present invention, based on the mass of the hydrogenation protective agent, the mass content of MoO3 is 2.0% to 7.0%, and the mass content of CoO is 0.3% to 1.7%.

[0011] In the present invention, based on the mass of the hydrogenation protective agent, the mass content of the alumina carrier is 91.3% to 97.7%.

[0012] In the present invention, the pore volume of the alumina carrier is 1.00 to 1.40 cm 3 / g, preferably 1.10 to 1.30 cm 3 / g.

[0013] In the present invention, the specific surface area of ​​the alumina carrier is 120 to 180 m 2 / g, preferably 130 to 170 m 2 / g.

[0014] In the present invention, the shape of the catalyst is preferably a four-leaf wheel or a four-leaf clover.

[0015] The third aspect of the present invention provides a method for preparing the above-mentioned hydrogenation protective agent, comprising the following steps:

[0016] a) mixing a first aluminum source, a second aluminum source, and a third aluminum source with water to obtain a slurry, and then grinding the slurry;

[0017] b) adding clean water to the slurry obtained in step a) and stirring;

[0018] c) adding a modifier, a pH regulator, and an optional dispersant to the material obtained in step b) to obtain a mixed slurry, and then subjecting the mixed slurry to a hydrothermal treatment;

[0019] d) drying the material obtained in step c) to obtain alumina dry glue;

[0020] e) mixing the alumina dry glue obtained in step d) with a binder, shaping, drying, and calcining to obtain a carrier;

[0021] f) impregnating the carrier obtained in step e) with an impregnation solution containing molybdenum and cobalt, and drying and calcining to obtain the hydrogenation protective agent.

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

[0023] In the method of the present invention, in step a), the second aluminum source is alumina gel having a water content of 35% by mass or less. The alumina gel can be a dehydrated alumina hydrate, and can be completely dehydrated alumina or partially dehydrated alumina, such as monohydrated alumina.

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

[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 size of the particles in the slurry is 4 to 20 μm, measured by the median particle size D50.

[0028] In the method of the present invention, in step b), the slurry obtained in step a) is added with clean water (preferably deionized water) and stirred so that the total mass content 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 regulator can be an alkaline substance (such as at least one of sodium hydroxide, ammonia water, 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 regulator is adjusted according to the properties of the slurry, and the pH value of the mixed slurry in step c) is controlled to be 8.5 to 12.0.

[0030] In the method of the present invention, in step c), the dispersant is selected from at least one hydrophilic dispersant. The dispersant can be a nonionic surfactant having an HLB value (Hydrophile-Lipophile Balance Number) of 10 to 20. The amount of the 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 ethylenediaminetetraacetic acid, sodium gluconate, sodium tartrate, etc. 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 conditions of the hydrothermal treatment are as follows: temperature is 220-280° C., and time is 5-12 hours.

[0032] In the method of the present invention, in step d), the material obtained in step c) may be filtered and washed before drying. Conventional filtering and washing methods may be employed. The drying conditions are as follows: a drying temperature of 100 to 180° C. and a drying time of 4 to 10 hours.

[0033] In the method of the present invention, in step e), the binder is selected from at least one of an inorganic acid, an organic acid, cellulose, and a resin. The inorganic acid may be nitric acid, and the organic acid may be selected from at least one of acetic acid, citric acid, and tartaric acid. The cellulose may be at least one of hydroxypropyl cellulose and methyl cellulose, and the resin may be at least one of phenolic resin and ethylene-vinyl acetate resin. The amount of the binder added is 0.1% to 10% of the mass of the dry alumina gel.

[0034] In the method of the present invention, in step e), a molding aid, such as an extrusion aid, may be added depending on the molding conditions. The extrusion aid is selected from sesbania powder and the amount of the extrusion aid added is 0.5% to 6.0% of the mass of the alumina dry glue obtained in step d).

[0035] In the method of the present invention, step e) does not require the addition of pore-forming raw materials, such as pore-enlarging agents. These raw materials, such as carbon black and starch, are added during the carrier preparation process. During the molding process, the pore-enlarging agent molecules are encapsulated by the alumina powder particles. After high-temperature calcination, the pore-enlarging agent molecules are oxidized or undergo other chemical reactions to generate gases that escape, leaving behind the spaces previously occupied, thereby forming large pores.

[0036] In the method of the present invention, in step e), the formed shape can be a four-leaf wheel or a four-leaf clover shape.

[0037] In the method of the present invention, in step e), the drying conditions after forming are as follows: a drying temperature of 100-180°C and a drying time of 4-12 hours; and the calcination conditions after forming are as follows: a calcination temperature of 500-800°C and a calcination time of 3-12 hours. The calcination atmosphere can be an oxygen-containing gas, such as air.

[0038] In the method of the present invention, in step f), the impregnation solution containing molybdenum and cobalt has a cobalt content of 0.2 to 1.6 g / 100 mL (calculated as cobalt oxide), and a molybdenum content of 1.6 to 6.3 g / 100 mL (calculated as molybdenum oxide). The molybdenum source may be at least one of ammonium molybdate and molybdenum trioxide. The cobalt source may be at least one of cobalt nitrate and basic cobalt carbonate.

[0039] In the method of the present invention, in step f), the impregnation is preferably carried out by saturation impregnation.

[0040] In the method of the present invention, in step f), the drying conditions after impregnation are as follows: a drying temperature of 100-180°C for a drying time of 4-12 hours; and the calcination conditions are as follows: a calcination temperature of 450-600°C for a calcination time of 3-6 hours. The calcination atmosphere is an oxygen-containing atmosphere, such as air.

[0041] The hydrogenation protective agent of the present invention is suitable for catalytic cracking slurry oil hydrogenation treatment, and is particularly suitable for being loaded in the upper layer of a catalytic cracking slurry oil hydrogenation unit. It is mainly used as a hydrogenation protective agent to protect the downstream main hydrogenation catalyst and provide guarantee for the long-term operation of the catalytic cracking slurry oil hydrogenation unit.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. In the prior art, catalytic cracking slurry and residual oil are similar in that both contain colloids and asphaltenes. However, catalytic cracking slurry and residual oil have different properties. The metal content in catalytic cracking slurry is relatively low, and the main cause of catalyst deactivation is the deposition of carbon deposits. The operating cycles of catalytic cracking slurry hydrogenation units and residual oil hydrogenation units are different. Catalytic cracking slurry hydrogenation units generally operate for two years, while residual oil hydrogenation units operate for about one year. Under different raw materials and different operating modes, a hydrogenation protective agent with as many large pores as possible can accommodate more carbon deposits, protect downstream catalysts, extend the service life of the catalyst, and ensure long-term operation of the unit. The present invention provides a hydrogenation protective agent suitable for catalytic cracking slurry hydrogenation, wherein the pore size of the carrier used is relatively large. According to the mercury intrusion test, the carrier has a pore size of 40 to 100 nm, and the pore size distribution is relatively concentrated, with the pore volume in the range of (pore size - 30) nm to (pore size + 30) nm accounting for more than 75% of the total pore volume of the carrier. The hydrogenation protectant carrier of the present invention has a suitable large pore size and a suitable large pore volume ratio, which can eliminate the diffusion resistance of macromolecules during adsorption and reaction on the catalyst surface during the hydrogenation of catalytic cracking oil slurry, and can accommodate more carbon deposits, which is beneficial to the long-term operation of the hydrogenation device.

[0044] 2. In the process of preparing 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 a hydrothermal treatment is performed. During the hydrothermal treatment process, different aluminum sources form different precursor particles, and then a rehydration reaction occurs. The alumina dry glue obtained after drying does not require additional pore-forming materials such as pore expanders. It is calcined at a relatively low temperature (below 800°C) to obtain the hydrogenation protective agent carrier of the present invention with suitable large pores and suitable large pore volume ratio.

[0045] 3. The present invention uses molybdenum and cobalt as active metals to prepare the hydrogenation protective agent. The prepared hydrogenation protective agent not only has high desulfurization selectivity, but also can retain the three-ring and four-ring aromatic hydrocarbons in the catalytic cracking oil slurry to a great extent, providing an ideal raw material for the preparation of high-end carbon-based materials such as needle coke.

[0046] Specific implementation method

[0047] The following examples further illustrate the technical solutions and effects of the present invention. The examples are implemented based on the technical solutions of the present invention, and provide detailed implementation methods and specific operating processes, but the scope of protection of the present invention is not limited to the following examples.

[0048] The experimental methods in the following examples, unless otherwise specified, are all conventional methods in the art. The experimental materials used in the following examples, unless otherwise specified, were purchased from conventional biochemical reagent stores.

[0049] The pore volumes and pore diameters of the alumina supports and catalysts of the present invention (including the examples), as well as those prepared in Comparative Examples 1, 2, and 4, and conventional residue oil hydrogenation protectant supports and catalysts, were measured using mercury intrusion porosimetry using a MicroActive AutoPore V 9600 instrument.

[0050] In the present invention, the pore volume and pore diameter of the alumina supports prepared in Comparative Examples 3 and 5 were tested using a low-temperature liquid nitrogen adsorption method using an ASAP2420 pore structure analyzer produced by Micromeritics, Inc., USA.

[0051] The specific surface areas of the alumina support components, alumina supports and catalysts in the present invention (including the examples) and the alumina support components, alumina supports and catalysts prepared in the comparative examples were measured using a low-temperature liquid nitrogen adsorption method using a Micromeritics ASAP2420 pore structure analyzer.

[0052] Example 1

[0053] Take 100 grams of alumina trihydrate, 100 grams of alumina monohydrate and 15 grams of sodium aluminate, add 300 grams of clean water, use a ball mill to grind, 500 rpm, grind for 1 hour, the particle D50 in the slurry is 6.05 μm. Add 1000 grams of clean water to the ground slurry and stir, then add 2 grams of acetic acid, 5 grams of sodium hexametaphosphate, and 10 grams of Tween-80, and the slurry pH value is 8.93. The stirred slurry is transferred to an autoclave for hydrothermal treatment at a hydrothermal temperature of 260°C and a hydrothermal time of 8 hours. The material obtained after hydrothermal treatment is filtered, washed, and dried at 120°C for 5 hours to obtain alumina dry glue.

[0054] 100 g of the prepared alumina gel was added to 1 g of sesbania powder, 2 g of methylcellulose, 0.5 g of acetic acid, and 130 g of purified water. The mixture was kneaded and formed into a four-impeller-shaped carrier. After forming, the carrier was dried at 120°C for 4 hours and calcined at 700°C for 4 hours. This produced hydrogenation protective agent carrier A.

[0055] An impregnation solution containing molybdenum and cobalt was prepared, wherein the molybdenum source was ammonium molybdate and the cobalt source was cobalt nitrate. The molybdenum content in the impregnation solution, calculated as molybdenum oxide, was 3.16 g / 100 mL, and the cobalt content, calculated as cobalt oxide, was 0.74 g / 100 mL. A hydrogenation protective agent carrier A was impregnated with the molybdenum and cobalt-containing impregnation solution using a saturated impregnation method. After impregnation, the carrier was dried at 120°C for 4 hours and calcined at 500°C for 4 hours to produce the catalytic cracking oil slurry hydrogenation protective agent A of the present invention.

[0056] Example 2

[0057] Compared with Example 1, the difference is that during the preparation of the alumina dry gel, 100 grams of aluminum oxide trihydrate, 85 grams of aluminum oxide monohydrate, and 15 grams of sodium metaaluminate were taken, 300 grams of purified water were added, and the mixture was ground using a ball mill to obtain the hydrogenation protective agent carrier B and the catalytic cracking oil slurry hydrogenation protective agent B of the present invention.

[0058] Example 3

[0059] Compared with Example 1, the difference is that in the preparation process of the alumina dry gel, 100 grams of aluminum oxide trihydrate, 100 grams of aluminum oxide monohydrate, and 10 grams of aluminum sulfate were taken, added to 300 grams of clean water, and ground using a ball mill; 1000 grams of clean water was added to the ground slurry and stirred, and then 8 grams of sodium hydroxide, 5 grams of sodium hexametaphosphate, and 10 grams of Tween-80 were added, and the slurry pH value was 9.14. The hydrogenation protective agent carrier C and catalytic cracking oil slurry hydrogenation protective agent C of the present invention were obtained.

[0060] Example 4

[0061] Compared with Example 1, the difference is that during the preparation of the alumina dry gel, 900 g of clean water is added to the ground slurry and stirred, and then 2 g of acetic acid and 9 g of sodium hexametaphosphate are added to obtain the hydrogenation protective agent carrier D and the catalytic cracking oil slurry hydrogenation protective agent D of the present invention.

[0062] Example 5

[0063] Compared with Example 1, the difference is that during the preparation of the alumina dry gel, the stirred slurry is transferred into an autoclave for hydrothermal treatment at a temperature of 270° C. and a hydrothermal time of 7 hours. Thus, the hydrogenation protective agent carrier E and the catalytic cracking oil slurry hydrogenation protective agent E of the present invention are obtained.

[0064] Example 6

[0065] Compared with Example 1, the difference is that the prepared alumina dry glue is kneaded and formed, dried at 120°C for 4 hours, and calcined at 750°C for 4 hours. The hydrogenation protective agent carrier F and catalytic cracking oil slurry hydrogenation protective agent F of the present invention are obtained.

[0066] Comparative Example 1

[0067] The same as Example 1, except that when alumina dry glue was used for kneading and molding, commercially available macroporous pseudo-boehmite was used. After molding, the mixture was dried at 120°C for 4 hours and calcined at 900°C for 4 hours to obtain the carrier DA.

[0068] An active metal solution was prepared with a molybdenum oxide content of 4.37 g / 100 mL and a cobalt oxide content of 1.02 g / 100 mL. The support was impregnated using a conventional saturated impregnation method. After impregnation, the solution was dried at 120°C for 4 hours and calcined at 500°C for 4 hours to produce a comparative hydrogenation protectant DA.

[0069] Comparative Example 2

[0070] Similar to Example 1, except that the active metal solution was prepared with a molybdenum oxide content of 3.16 g / 100 mL and a nickel oxide content of 0.74 g / 100 mL. Conventional saturated impregnation was used, followed by drying at 120°C for 4 hours and calcination at 500°C for 4 hours to produce comparative hydrogenation protectant DB.

[0071] Comparative Example 3

[0072] Compared with Example 1, the difference is that 100 g of trihydrated alumina and 100 g of monohydrated alumina are taken, 300 g of clean water are added, and the mixture is ground using a ball mill to obtain a carrier DC, and the active metal is impregnated. The content of molybdenum oxide in the solution is 4.63 g / 100 mL, and the content of cobalt oxide is 1.08 g / 100 mL, to obtain a comparative hydrogenation protective agent DC.

[0073] Comparative Example 4

[0074] Compared with Example 1, the difference is that 1000 g of clean water is added to the ground slurry and stirred, and then 2 g of acetic acid and 10 g of Tween-80 are added to obtain a carrier DD, and the active metal is impregnated. The content of molybdenum oxide in the solution is 4.14 g / 100 mL, and the content of cobalt oxide is 0.96 g / 100 mL, thereby preparing a comparative hydrogenation protective agent DD.

[0075] Comparative Example 5

[0076] Compared with Example 1, the difference is that 1000 g of clean water is added to the ground slurry and stirred, and then 6 g of nitric acid and 10 g of Tween-80 are added. The pH value of the slurry is 1.93 to obtain a carrier DE, and the active metal is impregnated. The content of molybdenum oxide in the solution is 7.87 g / 100 mL, and the content of cobalt oxide is 1.83 g / 100 mL, to prepare a comparative hydrogenation protective agent DE.

[0077] Tables 1, 2 and 3 list the properties of the supports and catalysts prepared in the above examples and comparative examples, wherein the pore distribution is single-peaked from (most probable pore diameter -30) nm to (most probable pore diameter +30) nm, with a peak width of at least 60 nm.

[0078] Table 1 Pore properties of the catalyst supports obtained in each example

[0079]

[0080] Table 2 Pore properties of the catalyst supports obtained in each comparative example

[0081] Carrier number DA DC DD DE FZC-12A vector <![CDATA[Pore volume, cm 3 / g]]> 0.83 0.61 0.76 0.43 0.85 <![CDATA[Specific surface area, m 2 / g]]> 149 221 187 240 123 Most probable pore diameter, nm 12.5 9 12.5 4.5 17.5 Pore ​​diameter distribution range, nm 5～17.5 4～17.5 7～25 - 7～25 The percentage of concentrated pore size to total pore volume, % 86 78 82 - 86

[0082] Table 3 Catalyst compositions and properties of various examples and comparative examples

[0083] Catalyst No. <![CDATA[MoO3,%]]> CoO, % <![CDATA[Pore volume, cm 3 / g]]> <![CDATA[Specific surface area, m 2 / g]]> A 3.74 0.87 1.17 149 B 3.74 0.87 1.12 155 C 3.76 0.89 1.18 147 D 3.75 0.87 1.15 152 E 3.74 0.87 1.24 138 F 3.74 0.88 1.20 143 DA 3.74 0.87 0.78 130 DB 3.75 0.87(NiO) 1.16 148 DC 3.74 0.87 0.59 210 DD 3.73 0.87 0.71 176 DE 3.74 0.86 030 227 FZC-12A 3.80 0.91(NiO) 0.73 113

[0084] Catalyst evaluation

[0085] The catalysts prepared in Examples 1-6 and Comparative Examples 1-5 and conventional residual oil hydrogenation protective agent (brand FZC-102) were taken in the same volume and respectively installed in the upper hydrogenation protective agent position of the catalytic cracking slurry hydrogenation 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 hydrogenation protective agent, hydrodemetallization catalyst (brand FZC-28), and hydrodesulfurization catalyst (brand FZC-33B)). The catalyst was vulcanized by wet vulcanization. The vulcanizing agent used was dimethyl disulfide (DMDS). The vulcanized oil was straight-run diesel. The vulcanizing agent accounted for 1.5% of the mass of the straight-run diesel. During the vulcanization process, the vulcanization was carried out at a constant temperature of 230°C for 8 hours and at a constant temperature of 320°C for 8 hours. The raw material was full-fraction slurry oil with a sulfur content of 0.96wt% and a density (20°C) of 1.096g / cm 3 The mass content of (three + four ring) aromatics is 57.2%. Process conditions: reaction pressure 6.0 MPa, reaction temperature 350 ° C, hydrogen to oil volume ratio 1000, liquid hourly space velocity 0.8h -1 The results of the hydrotreated catalytic cracking slurry obtained after 200 hours of operation are listed in Tables 4 and 5, and the results of the hydrotreated catalytic cracking slurry obtained after 1500 hours of operation are listed in Tables 6 and 7.

[0086] Table 4 Evaluation results of catalysts in various examples

[0087] Catalyst No. A B C D E F <![CDATA[Hydrogenation product density (20 °C), g / cm 3 > 1.050 1.048 1.051 1.049 1.053 1.052 Desulfurization rate, % 58.5 58.9 58.4 58.7 58.1 58.3 (Three-ring + four-ring) aromatic hydrocarbon retention rate, % 94.3 94.0 94.5 94.2 94.8 94.6

[0088] Table 5 Evaluation results of catalysts of various comparative examples

[0089] Catalyst No. DA DB DC DD DE FZC-12A <![CDATA[Hydrogenation product density (20 °C), g / cm 3 > 1.056 1.052 1.051 1.054 1.065 1.062 Desulfurization rate, % 55.5 57.5 57.6 57.4 53.1 54.8 (Three-ring + four-ring) aromatic hydrocarbon retention rate, % 92.2 91.2 91.1 91.4 93.2 92.5

[0090] Table 6 Evaluation results of catalysts in various examples

[0091] Catalyst No. A B C D E F <![CDATA[Hydrogenation product density (20 °C), g / cm 3 > 1.053 1.051 1.054 1.052 1.056 1.055 Desulfurization rate, % 56.0 56.4 55.9 56.2 55.6 55.8 (Three-ring + four-ring) aromatic hydrocarbon retention rate, % 94.5 94.2 94.7 94.4 95.0 94.8

[0092] Table 7 Evaluation results of catalysts of various comparative examples

[0093]

[0094] In Tables 4-7, the aromatics retention rate is the percentage of three- and four-ring aromatics in the hydrogenation product relative to the three- and four-ring aromatics in the feedstock. Three- and four-ring aromatics are ideal feedstock aromatics for producing high-end carbon-based materials such as needle coke, and the aromatics retention rate is the ideal aromatics retention rate.

[0095] It can be seen from Tables 4-7 that, compared with the comparison agent and the conventional hydrogenation protective agent, the hydrogenation protective agent prepared using the carrier of the present invention in combination with the original catalyst gradation makes the activity decay of the catalyst system slower, the catalyst system has better desulfurization activity selectivity and stability, and has a greater degree of retention rate for tricyclic and tetracyclic aromatic hydrocarbons.

[0096] The above describes in detail the specific embodiments of the present invention, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as the contents disclosed by the present invention and fall within the scope of protection of the present invention.

Claims

1. A catalytic cracking oil slurry hydrogenation protective agent, comprising a carrier and a hydrogenation active metal, wherein: An alumina carrier is used, and the hydrogenation active metals include molybdenum oxide and cobalt oxide. The properties of the alumina carrier are as follows: the most probable pore diameter is 40 to 100 nm, preferably 50 to 70 nm, and the pore volume occupied by pores from (most probable pore diameter - 30) nm to (most probable pore diameter + 30) nm accounts for more than 75% of the total pore volume, preferably 75% to 90%.

2. The hydrogenation protective agent according to claim 1, characterized in that Based on the mass of the hydrogenation protective agent, the mass content of MoO3 is 2.0% to 7.0%, and the mass content of CoO is 0.3% to 1.7%.

3. The hydrogenation protective agent according to claim 1, characterized in that The properties of the carrier are as follows: pore volume of 1.00 to 1.40 cm 3 / g, preferably 1.10 to 1.30 cm 3 / g; and / or, a specific surface area of ​​120 to 180 m 2 / g, preferably 130 to 170 m 2 / g.

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

5. The method for preparing the hydrogenation protective agent according to any one of claims 1 to 4, comprising the steps of: a) mixing a first aluminum source, a second aluminum source, and a third aluminum source with water to obtain a slurry, and then grinding the slurry; b) adding clean water to the slurry obtained in step a) and stirring; c) adding a modifier, a pH regulator, and an optional dispersant to the material obtained in step b) to obtain a mixed slurry, and then subjecting the mixed slurry to a hydrothermal treatment; d) drying the material obtained in step c) to obtain alumina dry glue; e) mixing the alumina dry glue obtained in step d) with a binder, shaping, drying, and calcining to obtain a carrier; f) impregnating the carrier obtained in step e) with an impregnation solution containing molybdenum and cobalt, and drying and calcining to obtain the hydrogenation protective agent.

6. The preparation method according to claim 5, characterized in that In step a), the first aluminum source is alumina trihydrate; the second aluminum source is alumina dry gel, whose water content is less than 35% by mass, preferably alumina monohydrate; the third aluminum source is an aluminum-containing salt compound, preferably selected from at least one of aluminum nitrate, aluminum chloride, aluminum sulfate, and sodium metaaluminate.

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 size of the particles in the slurry is 4 to 20 μm, measured by median particle size D50.

10. The preparation method according to claim 5, characterized in that In step b), clean water is added to the slurry obtained in step a) and stirred, so that the total mass content 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 In step c), the dispersant is a nonionic surfactant with an HLB value of 10 to 20, preferably at least one of Tween-80, lauryl alcohol polyoxyethylene ether, and methyl glucose polyoxyethylene ether; and / or the modifier is at least one of sodium hexametaphosphate, sodium tripolyphosphate, disodium ethylenediaminetetraacetic acid, sodium gluconate, and sodium tartrate.

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

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

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

16. The preparation method according to claim 5, characterized in that The drying conditions after molding are as follows: the drying temperature is 100-180° C. and the drying time is 4-12 hours; the calcination conditions after molding are as follows: the calcination temperature is 500-800° C. and the calcination time is 3-12 hours; and / or, in step f), the impregnation adopts a saturated impregnation method; preferably, in step f), the drying conditions after impregnation are as follows: the drying temperature is 100-180° C. and the drying time is 4-12 hours; the calcination conditions are as follows: the calcination temperature is 450-600° C. and the calcination time is 3-6 hours.

17. Use of the hydrogenation protective agent according to any one of claims 1 to 4 in the hydrotreatment of catalytic cracking slurry oil.

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