A catalyst for preparing light aromatic hydrocarbons from low-value raw materials and its preparation and application

Abstract

The present invention relates to a catalyst for preparing light aromatic hydrocarbons from low-value raw materials, and its preparation and application. The catalyst comprises zeolite, metal oxide, binder and optional metal function regulating component; wherein the zeolite comprises beta zeolite with a B / L value of 1 to 10 and ZSM-5 zeolite with a B / L value of 1 to 15. The catalyst is suitable for catalytic hydrocracking of diesel, and has the characteristics of strong stability, high single-pass conversion rate, high yield of light aromatic hydrocarbons and olefin cracking materials, etc.

Description

Technical Field

[0001] The invention belongs to the catalyst technology in the field of refining and hydrogenation, and specifically relates to a catalyst for preparing light aromatics from low-value raw materials and the preparation and application thereof. Background Art

[0002] Light aromatics, such as benzene, toluene and xylene, as basic raw materials for organic chemicals, play a vital role in the modern petrochemical industry. With the rapid growth of my country's economy and the rapid development of the polyester, synthetic rubber, fiber and resin industries, the demand for light aromatics is growing. At present, there are two main methods for producing light aromatics: (1) catalytic reforming of naphtha and (2) naphtha cracking as by-product aromatics. As a basic raw material for organic chemicals, traditional production methods can no longer meet the current market demand. Finding alternative production raw materials and exploring new technical paths for the production of light aromatics have extremely important practical significance and market prospects.

[0003] Catalytic diesel (LCO) is a type of oil product rich in polycyclic aromatic components, with a total aromatic content of 70% to 90%. The annual production of catalytic diesel exceeds 40 million tons. From the perspective of resource utilization, catalytic diesel has low added value due to the large amount of inferior polycyclic aromatics it contains. Considering catalytic cracking diesel as a raw material for directly producing high-value-added light aromatics has very promising prospects for corporate transformation and profitability. In 2007, UOP developed and designed the LCO-X process for the production of xylene and benzene by LCO hydroconversion-selective alkylation. Among them, the yields of xylene and benzene are 32% and 12%, respectively. In 2010, NOVA Chemicals developed the ARO (aromatic ring-opening) technology, which has the highest BTEX yield of about 18% at a reaction temperature of 380°C. In 2013, Sinopec Fushun Petrochemical Research Institute developed a new FD2G technology for efficient hydrogenation conversion of light aromatics from catalytic cracking diesel rich in aromatics. However, studies have shown that this technology has a low overall BTX yield and cannot bring significant economic benefits to refineries. Therefore, the selective conversion of LCO into light aromatics can not only increase the added value of diesel, but also meet my country's growing demand for aromatics. However, research on this technology is still in its early stages. There have been related reports that there are generally problems such as low conversion rate of heavy aromatics, nitrogen resistance and poor selectivity. The key lies in the preparation of high-performance catalysts.

[0004] Molecular sieve catalysts are a type of catalyst that uses molecular sieve as the catalytic active component or one of the main active components. Due to its high hydrothermal stability, good selectivity and acidity, molecular sieve catalysts have shown excellent catalytic performance in reactions such as hydroisomerization, hydrocracking, aromatic alkylation, and toluene disproportionation. In particular, metal-loaded molecular sieve catalysts with dual-functional catalysis contain both metal and acid functions, and they play a very important role in hydrocracking. The production of light aromatics using catalytic diesel as raw material includes a variety of reactions, and the catalyst must have both hydrogenation and cracking functions. Perfectly matching the two functions of the catalyst will make the catalyst show a balance between high activity, high selectivity, high stability, and low carbon deposition rate, which is a major challenge. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the catalyst for converting low-value catalytic diesel into high-value-added light aromatics has poor stability, low conversion rate and low yield. The catalyst provided by the present invention is suitable for use in the hydrocracking reaction of feedstock oil rich in condensed ring aromatics or long-chain alkyl monocyclic aromatics, and has the characteristics of strong stability, high single-pass conversion rate, high yield of light aromatics and olefin cracking materials, etc.

[0006] One of the purposes of the present invention is to provide a catalyst for preparing light aromatic hydrocarbons from low-value raw materials, comprising: zeolite, metal oxide, and binder; wherein the zeolite comprises beta zeolite with a B / L value (ratio of B acid to L acid) of 1 to 10 and ZSM-5 zeolite with a B / L value of 1 to 15.

[0007] Preferably, the silicon-aluminum ratio of the beta zeolite is 10 to 200, preferably 15 to 100;

[0008] The silicon-aluminum ratio of the ZSM-5 zeolite is 25 to 100, preferably 25 to 50;

[0009] The metal oxide is selected from at least one of oxides of molybdenum, platinum, gallium and tungsten;

[0010] The binder is selected from at least one of aluminum oxide and silicon oxide;

[0011] In the catalyst, based on 100 parts by weight of the total amount of the zeolite, the metal oxide is 1 to 10 parts, preferably 1 to 5 parts; the binder is 20 to 80 parts, preferably 30 to 60 parts;

[0012] In terms of mass percentage, the beta zeolite accounts for ≥50% of the total weight of the zeolite, preferably 70%≤beta zeolite accounts for <100% of the total weight of the zeolite; wherein the beta zeolite plays a dominant role in ring-opening cracking, and the ZSM-5 zeolite can achieve the dealkylation of the side chain alkanes of the monocyclic aromatic hydrocarbons;

[0013] Based on 100 parts by weight of the total amount of the zeolite, 0 to 10 parts of a metal function regulating component, preferably 0.5 to 5 parts of a metal function regulating component, are added to the catalyst. The metal function regulating component is selected from at least one of Group VIII metal oxides and Group IIB metal oxides, preferably at least one of nickel oxide, cobalt oxide, and zinc oxide.

[0014] The second object of the present invention is a method for preparing the above-mentioned catalyst for preparing light aromatic hydrocarbons, comprising loading the metal oxide on a component including the zeolite and a binder, to obtain the catalyst for preparing light aromatic hydrocarbons. Preferably, the preparation method specifically comprises the following steps:

[0015] Step 1) fully mixing the components including the β zeolite, ZSM-5 zeolite and a binder, extruding, drying and calcining to obtain a catalyst carrier;

[0016] Step 2) preparing an aqueous solution of a soluble metal compound;

[0017] Step 3) The catalyst carrier obtained in step 1) is immersed in the aqueous solution of the metal compound obtained in step 2), and the catalyst is obtained after drying and calcining.

[0018] Specifically,

[0019] In the step 1), the drying temperature is 90-150°C, preferably 100-120°C; the calcination temperature is 550-600°C, preferably 550-580°C; the calcination time is 2-5h, preferably 3-4h;

[0020] In the step 2), the soluble metal compound is selected from at least one of soluble metal compounds of molybdenum, platinum, gallium, and tungsten, and optionally at least one of soluble metal compounds of Group VIII metals and Group IIB metals; preferably selected from at least one of ammonium molybdate, ammonium tungstate, chloroplatinic acid, and gallium nitrate, and optionally at least one of nickel nitrate, nickel sulfate, nickel halide, nickel oxalate, nickel acetate, cobalt nitrate, cobalt chloride, cobalt oxalate, zinc nitrate, zinc chloride, zinc oxalate, and zinc acetate; the concentration of the aqueous solution of the soluble metal compound is 1 to 20%, preferably 5 to 15%;

[0021] In the step 3), the impregnation can be completed at room temperature for 2 to 6 hours, preferably 4 to 6 hours; the drying temperature is 90 to 150°C, preferably 100 to 120°C; the calcination temperature is 550 to 600°C, preferably 550 to 580°C; the calcination time is 2 to 5 hours, preferably 3 to 4 hours;

[0022] In the above preparation method, the drying and calcining can adopt the drying equipment, calcining equipment and common process conditions commonly used in the art; the impregnation treatment can adopt the common impregnation process, preferably equal volume impregnation.

[0023] The third object of the present invention is to provide an application of the above-mentioned catalyst for preparing light aromatics or the catalyst for preparing light aromatics prepared by the above-mentioned preparation method for the hydrocracking reaction of low-value raw materials. The application comprises the following steps: the low-value raw materials are subjected to hydrorefining treatment, and then hydrocracking is performed under the action of the catalyst for preparing light aromatics to obtain light aromatics.

[0024] Wherein, the low-value raw material is selected from at least one of catalytic diesel, DCC heavy gasoline, and heavy aromatics bottom feed;

[0025] After the low-value raw materials are treated with hydrogenation, the nitrogen content is ≤20ppm and the aromatics retention rate is ≥90%;

[0026] The reaction conditions of the hydrocracking include: reaction temperature of 300-450°C, hydrogen partial pressure of 2.0-15.0 MPa, weight space velocity of 0.2-10.0 h -1 , the volume ratio of hydrogen to hydrocarbon is 500 to 4000; preferably, the reaction temperature is 350 to 380°C, the hydrogen partial pressure is 6 to 10 MPa, and the weight space velocity is 0.2 to 2 h -1 , the volume ratio of hydrogen to hydrocarbon is 2000-4000;

[0027] The single-pass conversion rate of the hydrocracking reaction is ≥75%, BTX (benzene-toluene-xylene mixture), C9A and C 10 A yield ≥35%, selectivity ≥40%.

[0028] The basic nitrides in the feedstock oil participate in the catalyst coking process, especially the L acid center. After the basic nitrides are adsorbed on the L acid center on the catalyst surface, there is little chance to desorb before generating coke. As a result, the L acid center is easy to interact with the basic nitride to generate coke to block the pores and cause the catalyst to deactivate quickly. In addition, the basic nitrides are easy to combine with the protons provided by the B acid center of the catalyst, so that the number of B acid centers is reduced, affecting the activity of the catalyst. Therefore, to reduce the rapid deactivation of the catalyst during the operation of the catalyst but at the same time to ensure the activity of the catalyst, the catalyst must have a lower L acid center and a sufficient concentration of B acid centers. In the catalyst of the present invention, a composite zeolite with a specific B / L value is used, especially a β zeolite with a B / L value of 1 to 10 and a ZSM-5 type zeolite with a B / L value between 1 and 15, and a reasonable component ratio is used, so that the catalyst provided by the present invention not only has a strong cracking ability, is not easy to produce carbon deposition, but also exhibits a relatively excellent nitrogen resistance, which is very important for the long-term stable operation of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The three refined raw materials of catalyst C-1 of the present invention are BTX+C9A and C 10 A yield is the yield of aromatics. DETAILED DESCRIPTION

[0030] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0031] The test instruments and test conditions used in the examples are as follows:

[0032] The liquid products were analyzed by Agilent 7890A gas chromatograph, hydrogen flame ionization detector, HP-1 60m*0.25mm*0.25μm capillary column, detector temperature 250°C, injection port temperature 250°C, and the analysis data were quantified by area normalization method, wherein the liquid products were directly introduced into the chromatograph through a high-pressure liquid injection valve.

[0033] The gas phase products were analyzed by Agilent 7890A gas chromatograph with a hydrogen flame ionization detector. The chromatographic column used was an HP-Al / S type 50m*0.53mm*15μm capillary column, and the tail gas composition was quantified by the external standard method.

[0034] The content of liquid and gas phase products was measured by chromatography and the single-pass heavy aromatics (C 11 and above components) conversion rate and products (BTX, C9A and C 10 A) Selectivity. The single-pass conversion rate is calculated by the formula (C 11 And above component content - C in the product 11 and above components) / C in raw materials 11 and above components*100%; the formula for calculating product selectivity is the yield of target product (BTX, C9A and C 10 A) / simple conversion rate*100%, wherein the xylene refers to a mixture of o-xylene, p-xylene and m-xylene.

[0035] The evaluation was carried out using a micro-reactor fixed bed apparatus. The catalyst was loaded into a fixed bed reactor and the parameters were set. The reactor was run continuously for 300 hours and the liquid and gas product contents were tested by gas chromatography every 48 hours. If the calculated conversion rate, yield and selectivity were stable, the catalyst had good stability.

[0036] The hydrorefining catalyst and raw materials involved in the specific implementation of the present invention are:

[0037] 1. The hydrofining catalyst involved in the embodiment of the present invention is the commercially available catalyst HT-1, which has a composition of 5.73wt% NiO-35.15wt% MoO3-4.66% P2O5-54.46% Al2O3. Hydrofining catalysts with similar composition and performance indicators can meet the requirements of this technical solution.

[0038] 2. To illustrate the effect of the present invention, three representative catalytic diesels are provided. After the catalytic diesels are subjected to a common hydrorefining process, refined raw oil 1, refined raw oil 2 and refined raw oil 3 are obtained. The compositions are shown in Table 1.

[0039] Table 1. Composition of stock oils 1 to 3 and refined stock oils 1 to 3

[0040]

[0041] [Example 1]

[0042] The hydrogen-type β zeolite of the present invention (silicon-aluminum ratio SAR=62.7, purchased from Sinopec Catalyst Co., Ltd.), wherein the B / L value is 2.90, wherein the β zeolite content accounts for 90% of the total zeolite proportion; the hydrogen-type ZSM-5 zeolite (silicon-aluminum ratio SAR=29.8, purchased from Sinopec Catalyst Co., Ltd.), wherein the B / L value is 13.06.

[0043] The above-mentioned hydrogen-type β zeolite, hydrogen-type ZSM-5 zeolite and pseudo-boehmite are fully mixed, kneaded, extruded, dried at 120°C and then calcined in a muffle furnace at 550°C for 2 hours to obtain the desired catalyst carrier.

[0044] 50 ml of bimetallic aqueous solution was prepared with 6.4 g of nickel nitrate and 7.8 g of ammonium molybdate, and the catalyst carrier was impregnated by an equal volume impregnation method for 4 hours at room temperature. After drying at 90°C, the catalyst was calcined in an air atmosphere muffle furnace at 550°C for 2 hours to obtain catalyst C-1.

[0045] The evaluation was conducted using a micro-reacted fixed bed device. Catalyst C-1 was loaded into a fixed bed reactor. Refined crude oil 1, hydrogen partial pressure 7.5 MPa, hydrogen-to-oil ratio 2000 were used. C-1 hydrocracking catalyst weight space velocity (WHSV) 1.0 h -1 , reaction temperature 370℃.

[0046] A high-pressure separator was set at the outlet of the hydrocracking reactor. After the device was stably operated for 48 hours, the product composition was analyzed by gas chromatography and the heavy aromatics (C 11 and C 11+ Aromatic hydrocarbons) conversion rate, BTX, C9A, C10 The yield and selectivity of A are shown in Table 2.

[0047] [Example 2]

[0048] The method of Example 1 is followed, except that refined crude oil 2 is used as the reaction raw material.

[0049] [Example 3]

[0050] The method of Example 1 is followed, except that refined crude oil 3 is used as the reaction raw material.

[0051] [Example 4]

[0052] The method of Example 1 was followed, except that hydrogen-type β zeolite (silicon-aluminum ratio SAR=67.5, purchased from Sinopec Catalyst Co., Ltd.) was used, and its B / L value was 3.97. Others were the same as in Example 1.

[0053] [Example 5]

[0054] The method of Example 1 was followed, except that hydrogen-type β zeolite (silicon-aluminum ratio SAR=70, purchased from Sinopec Catalyst Co., Ltd.) was used, and its B / L value was 1.68. Other procedures were the same as in Example 1.

[0055] [Example 6]

[0056] The method of Example 1 is followed, except that the impregnation solution is 3.93 g zinc nitrate and 7.8 g ammonium molybdate prepared in 50 ml of bimetallic aqueous solution, and the rest is the same as Example 1.

[0057] [Example 7]

[0058] The method of Example 1 is followed, except that the impregnation solution is 50 ml of bimetallic aqueous solution prepared with 3.44 g of ammonium metatungstate and 6.4 g of nickel nitrate, and the rest is the same as Example 1.

[0059] [Example 8]

[0060] The method of Example 1 is followed, except that the hydrogen-to-oil volume ratio is 4000, and the rest is the same as Example 1.

[0061] [Example 9]

[0062] The method of Example 1 is followed, except that the hydrogen partial pressure is 8.0 MPa, and the rest is the same as Example 1.

[0063] [Example 10]

[0064] The method of Example 1 was followed, except that the hydrocracking reaction temperature was 380° C., and the rest was the same as Example 1.

[0065] [Example 11]

[0066] The method of Example 1 was followed, except that after the device was stably operated for 300 hours, the product composition was analyzed by gas chromatography and the conversion rate was calculated. 10 A yield and selectivity, the others are the same as in Example 1.

[0067] [Example 12]

[0068] The method of Example 1 was followed, except that the hydrocracking weight space velocity was 2.0 h -1 , reaction temperature 375°C, and other procedures are the same as in Example 1.

[0069] [Example 13]

[0070] The method of Example 1 was followed, except that the hydrocracking weight hourly velocity was 1.5 h -1 , the hydrogen partial pressure is 7.0 MPa, and the rest is the same as in Example 1.

[0071] [Example 14]

[0072] The method of Example 1 was followed, except that the content of β zeolite accounted for 75% of the total zeolite, and the hydrogen-type ZSM-5 zeolite (silicon-aluminum ratio SAR=25.12, purchased from Sinopec Catalyst Co., Ltd.) had a B / L value of 5.33. Others were the same as in Example 1.

[0073] [Example 15]

[0074] The method of Example 1 was followed, except that the content of β zeolite accounted for 85% of the total zeolite, and the hydrogen-type ZSM-5 zeolite (silicon-aluminum ratio SAR=37.88, purchased from Sinopec Catalyst Co., Ltd.) had a B / L value of 6.04. Others were the same as in Example 1.

[0075] [Comparative Example 1]

[0076] The method of Example 1 was followed, except that hydrogen-type β zeolite (silicon-aluminum ratio SAR=62.7, purchased from Sinopec Catalyst Co., Ltd.) was used, wherein the content of β zeolite accounted for 30% of the total zeolite content, and the rest was the same as in Example 1.

[0077] [Comparative Example 2]

[0078] The method of Example 1 was followed, except that hydrogen-type β zeolite (silicon-aluminum ratio SAR=59.88, purchased from Sinopec Catalyst Co., Ltd.) was used, and its B / L value was 0.92. Other aspects were the same as in Example 1.

[0079] [Comparative Example 3]

[0080] The method of Example 1 was followed, except that hydrogen-type β zeolite (silicon-aluminum ratio SAR=62.7, purchased from Sinopec Catalyst Co., Ltd.) was used, and the β zeolite content accounted for 100% of the total zeolite content. Other aspects were the same as in Example 1.

[0081] [Comparative Example 4]

[0082] The method of Example 1 was followed, except that hydrogen-type ZSM-5 zeolite (silicon-aluminum ratio SAR=29.8, purchased from Sinopec Catalyst Co., Ltd.) was used, and the content of ZSM-5 zeolite accounted for 100% of the total zeolite content. Other aspects were the same as in Example 1.

[0083] [Comparative Example 5]

[0084] The method of Example 11 was followed, except that hydrogen-type β zeolite (silicon-aluminum ratio SAR=59.88, purchased from Sinopec Catalyst Co., Ltd.) was used, and its B / L value was 0.92. Other procedures were the same as those of Example 11.

[0085] [Comparative Example 6]

[0086] The method of Example 11 was followed, except that hydrogen-type β zeolite (silicon-aluminum ratio SAR=34.15, purchased from Sinopec Catalyst Co., Ltd.) was used, and its B / L value was 10.78. Other procedures were the same as in Example 1.

[0087] Table 2. Hydrocracking reaction results of catalysts obtained from Examples 1 to 13 and Comparative Examples 1 to 5

[0088]

[0089] As can be seen from Table 2, the embodiments using the specific method of the present invention have higher heavy aromatics (C 11 and C 11+ Aromatics) conversion and higher BTX, C9A, C 10 By comparing Example 1 with Comparative Examples 1-4, it can be seen that when the β molecular sieve accounts for more than 70% of the total amount of zeolite, it is more conducive to the reaction to produce BTX, C9A, C 10 A, its yield is increased by at least 4%-20%.

[0090] Among them, by comparing Example 1 with Examples 4-5 and Examples 8-10, it can be seen that the preferred scheme of selecting the conversion reaction conditions of the present invention can further improve the conversion rate of BTX, C9A, C 10 By comparing Example 11 with Comparative Example 5, it can be seen that the preferred B / L value of the present invention is used to select the conversion catalyst. In the long-term stable evaluation, the conversion rate is higher, and BTX, C9A, C 10The yield and selectivity of A are higher, which shows that the catalyst provided by the present invention not only has a strong cracking ability, is not easy to produce carbon deposition, has excellent nitrogen resistance, and can operate stably for a long period of time.

[0091] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A catalyst for preparing light aromatic hydrocarbons, comprising: Zeolite, metal oxide and binder; wherein the zeolite comprises beta zeolite with a B / L value of 1 to 10 and ZSM-5 zeolite with a B / L value of 1 to 15, the silicon-aluminum ratio of the beta zeolite is 10 to 200, and the silicon-aluminum ratio of the ZSM-5 zeolite is 25 to 100; in terms of mass percentage, the beta zeolite accounts for ≥50% of the total weight of the zeolite; the metal oxide is selected from at least one of the oxides of molybdenum, platinum, gallium and tungsten.

2. The catalyst according to claim 1, characterized in that The silicon-aluminum ratio of the beta zeolite is 15 to 100; and / or, The silicon-aluminum ratio of the ZSM-5 zeolite is 25 to 50; and / or, The binder is selected from at least one of aluminum oxide and silicon oxide.

3. The catalyst according to claim 1, characterized in that In the catalyst, Based on 100 parts by weight of the total amount of the zeolite, the metal oxide is 1 to 10 parts; the binder is 20 to 80 parts; and / or, In terms of mass percentage, 70% ≤ beta zeolite accounts for <100% of the total weight of zeolite; and / or, Based on 100 parts by weight of the total amount of the zeolite, 0 to 10 parts of a metal function regulating component are added to the catalyst.

4. The catalyst according to claim 3, characterized in that In the catalyst, Based on 100 parts by weight of the total amount of the zeolite, the metal oxide is 1 to 5 parts; the binder is 30 to 60 parts; and / or, Based on 100 parts by weight of the total amount of the zeolite, 0.5 to 5 parts of a metal function regulating component are added to the catalyst.

5. The catalyst according to claim 3, characterized in that The metal function regulating component is selected from at least one of Group VIII metal oxides and Group IIB metal oxides.

6. The catalyst according to claim 5, characterized in that The metal function regulating component is selected from at least one of nickel oxide, cobalt oxide and zinc oxide.

7. A method for preparing the catalyst for preparing light aromatic hydrocarbons according to any one of claims 1 to 6, comprising loading the metal oxide on a component including the zeolite and a binder to obtain the catalyst for preparing light aromatic hydrocarbons.

8. The preparation method according to claim 7, characterized in that: The preparation method specifically comprises the following steps: Step 1) fully mixing the components including the β zeolite, ZSM-5 zeolite and a binder, extruding, drying and calcining to obtain a catalyst carrier; Step 2) preparing an aqueous solution of a soluble metal compound; Step 3) The catalyst carrier obtained in step 1) is immersed in the aqueous solution of the metal compound obtained in step 2), and the catalyst is obtained after drying and calcining.

9. The preparation method according to claim 8, characterized in that: In the step 1): The drying temperature is 90-150°C; and / or, The calcination temperature is 550-600°C and the calcination time is 2-5h.

10. The preparation method according to claim 9, characterized in that: In the step 1): The drying temperature is 100-120°C; and / or, The calcination temperature is 550-580°C, and the calcination time is 3-4h.

11. The preparation method according to claim 8, characterized in that: In the step 2): The soluble metal compound is selected from at least one of soluble metal compounds of molybdenum, platinum, gallium, and tungsten, and optionally at least one of soluble metal compounds of Group VIII metals and Group IIB metals; and / or, The concentration of the aqueous solution of the soluble metal compound is 1 to 20%.

12. The preparation method according to claim 11, characterized in that: In the step 2): The soluble metal compound is selected from at least one of ammonium molybdate, ammonium metatungstate, chloroplatinic acid, and gallium nitrate, and optionally at least one of nickel nitrate, nickel sulfate, nickel halide, nickel oxalate, nickel acetate, cobalt nitrate, cobalt chloride, cobalt oxalate, zinc nitrate, zinc chloride, zinc oxalate, and zinc acetate; and / or, The concentration of the aqueous solution of the soluble metal compound is 5-16%.

13. The preparation method according to claim 8, characterized in that: In the step 3): The immersion time is 2 to 6 hours; and / or, The drying temperature is 90-150°C; and / or, The calcination temperature is 550-600°C and the calcination time is 2-5h.

14. The preparation method according to claim 13, characterized in that: In the step 3): The immersion time is 4 to 6 hours; and / or, The drying temperature is 100-120°C; and / or, The calcination temperature is 550-580°C, and the calcination time is 3-4h.

15. Use of the catalyst for preparing light aromatic hydrocarbons according to any one of claims 1 to 6 or the catalyst for preparing light aromatic hydrocarbons prepared by the preparation method according to any one of claims 7 to 14 for hydrocracking reaction of low-value raw materials.

16. The use according to claim 15, characterized in that The application comprises the following steps: subjecting the low-value raw materials to hydrogenation refining treatment, and then hydrocracking them under the action of a catalyst for preparing light aromatics to obtain light aromatics.

17. The use according to claim 15, characterized in that: The low-value raw material is selected from at least one of catalytic diesel, DCC heavy gasoline, and heavy aromatics bottom feed; and / or, The nitrogen content of the low-value raw materials after hydrofining pretreatment is ≤20ppm and the aromatics retention rate is ≥90%; and / or, The reaction conditions of the hydrocracking include: reaction temperature of 300-450°C, hydrogen partial pressure of 2.0-15.0 MPa, weight space velocity of 0.2-10.0 h -1 , the volume ratio of hydrogen to hydrocarbon is 500 to 4000; and / or, The single-pass conversion rate of the hydrocracking reaction is ≥75%, and the BTX, C9A and C 10 A yield ≥35%, selectivity ≥40%.

18. The use according to claim 17, characterized in that The reaction conditions of the hydrocracking include: reaction temperature of 350-380°C, hydrogen partial pressure of 6-10 MPa, weight space velocity of 0.2-2 h -1 , the volume ratio of hydrogen to hydrocarbon is 2000-4000.

Images