Method for preparing BTX by hydrocracking aromatic-rich distillate oil, hydrocracking catalyst as well as preparation method and application of hydrocracking catalyst

Abstract

The invention relates to the field of hydrocracking, in particular to a method for preparing BTX through hydrocracking of aromatic-rich distillate oil, a hydrocracking catalyst and a preparation method and application of the hydrocracking catalyst, and the catalyst comprises the following components: a) 0.01%-1.5% of Pd; b) 50% to 90% of ZSM-5; c) 5%-50% of beta zeolite; d) 5%-20% of a binder; and the carbon deposition amount of the catalyst is 0.1-3% of the weight of the catalyst. The catalyst disclosed by the invention has very high stability and long operation cycle under the process conditions that the pressure is 2-6MPa, the temperature is 300-500 DEG C and the air speed is 0.8-4h <-1 >.

Description

Technical Field

[0001] The invention relates to a hydrocracking catalyst, a preparation method and application thereof, and a method for preparing BTX by hydrocracking aromatic-rich fraction oil. Background Art

[0002] Light aromatic distillate oil mainly refers to hydrocarbons with a distillation range below 300°C, and light oil products mainly composed of aromatic hydrocarbons, such as cracked C 9 + , ethylene tar, coal tar, light cracked diesel, etc. The main components of these oil products are monocyclic and polycyclic aromatic compounds with short side chains, high carbon-to-hydrogen ratio, high sulfur and nitrogen content, high density, low cetane number and poor stability, which are difficult to meet the standards of clean oil products. A highly severe hydrogenation process is required to be used as a blending component of clean diesel, but the operating cost is high and the economic benefits are poor.

[0003] According to the Notice on the Implementation of Consumption Tax Policies for Some Finished Oil Products, starting from July 1, 2023, the state will impose consumption tax on mixed aromatics, heavy aromatics, mixed C8, stable light hydrocarbons, light oil, and light coal tar in accordance with naphtha. This further increases the cost of light aromatic-rich distillate oil as an oil product.

[0004] Previously, many domestic and foreign manufacturers used rich aromatic fractions to produce aromatic solvent oils. Domestically, these were mainly private manufacturers, such as Jiangsu Hualun Chemical Co., Ltd. and Nantong Runfeng Petrochemical Co., Ltd. Major foreign manufacturers include Exxon in the United States, Shell in the Netherlands, and Maruzen Oil Company in Japan. With the implementation of new domestic regulations in 2023, the already overproduced aromatic solvent oil industry has been further aggravated, with rising costs and further declining profits, facing the dilemma of industry losses.

[0005] Therefore, developing the chemical utilization of rich aromatic fractions, giving full play to the advantages of aromatic resources in rich aromatic fractions, and producing light aromatics are the best choices for the high added value utilization of such oil products.

[0006] Light aromatic hydrocarbons, such as benzene, toluene and xylene, are important basic chemical raw materials with a wide range of uses. They can be used as organic chemical raw materials in the petrochemical industry, and are also the main raw materials for the production of synthetic fibers, synthetic rubber, synthetic resins, and various fine chemical products.

[0007] In order to make full use of the aromatic resources in the aromatic-rich distillate oil, it is necessary to convert the low value-added aromatic-rich distillate oil into BTX through catalytic conversion technology to realize the chemical utilization of the aromatic-rich distillate oil.

[0008] The catalytic conversion technology of rich aromatic fraction oil has been gradually applied in industry since the 1970s. At present, we have mature catalytic cracking feedstock pretreatment technologies, mainly including: UOP's VGO Unionfining and APCU (partial conversion hydrocracking) technology, Haldor The company's Aroshift technology, Chevron's VGO Hydrotreating technology, Exxon's VGO Hydrodesulfurization technology, IFP's T-star technology, and Mobil, AKZO, Kellogg's MAKfinging technology, etc. In order to further improve product quality and conversion rate, the catalytic feedstock hydrogenation pretreatment process has gradually changed from traditional hydrodesulfurization refining (HDS) to mild hydrocracking (MHC) to improve the denitrification, residual carbon and polycyclic aromatic hydrocarbons saturation capabilities.

[0009] These technologies generally use hydrogenation saturation and hydrocracking processes, which not only consumes a lot of hydrogen for aromatic-rich cracking distillate oil with high aromatic content, but also wastes precious aromatic resources. Some technologies, such as CN102234539A, also fully saturate the aromatics in the aromatic-rich oil and then hydrocracking to produce gasoline and diesel, which has high production costs and is not economical.

[0010] Based on technologies such as distillate hydrodesulfurization (HDS) and denitrogenation (HDN), optimization and innovation are carried out. Through hydrogenation, cracking, alkyl transfer and other means, the production of benzene (B), toluene (T) and xylene (X) can be maximized, and the refined light aromatic distillate oil can be fully utilized to increase its added value. Summary of the invention

[0011] In view of the problems of low BTX yield and catalyst stability in the prior art in the high value-added chemical utilization of refined light aromatic-rich cracking distillate oil, the present invention provides a new hydrocracking catalyst, which is used for high-stability refined light aromatic-rich distillate oil to produce BTX and has excellent stability.

[0012] To achieve the above-mentioned object, according to a first aspect of the present invention, the present invention provides a hydrocracking catalyst, which comprises the following components based on the total weight of the catalyst:

[0013] a) 0.01% to 1.5% Pd;

[0014] b) 50% to 90% ZSM-5;

[0015] c) 5% to 50% beta zeolite;

[0016] d) 5% to 20% binder;

[0017] The amount of carbon deposited on the catalyst is 0.1% to 3% of the weight of the catalyst.

[0018] The hydrocracking catalyst provided by the present invention has the advantage of long-term high-stability operation. In the present invention, the test method for the carbon deposition characteristics of the catalyst is a thermogravimetric analysis method.

[0019] According to a preferred embodiment of the present invention, preferably, the dispersion degree of the active component Pd is greater than 18%, preferably greater than 20%, preferably 20-35%.

[0020] In the present invention, the adhesive can be selected from a wide range of types, and all commonly used adhesives can be used in the present invention. For the present invention, the adhesive can be selected from silicon dioxide and / or aluminum oxide, for example.

[0021] In the present invention, both ZSM-5 and β zeolite can be used in the present invention. In the present invention, the preferred ZSM-5 powder is hydrogen type, SiO 2 / Al 2 O 3 The molar ratio is 20-200.

[0022] According to a preferred embodiment of the present invention, the beta zeolite is in the hydrogen form, SiO 2 / Al 2 O 3 The molar ratio is 20-200.

[0023] According to a preferred embodiment of the present invention, in the catalyst, by weight percentage, Pd is 0.1% to 1.5%, ZSM-5 is 55% to 85%, beta zeolite is 6% to 45%, and the binder content is 5% to 15%.

[0024] The catalysts having the above-mentioned characteristics of the present invention can be used in the present invention. There is no special requirement for the preparation method of the catalyst. For the present invention, the preferred preparation method of the catalyst includes:

[0025] i) preparing a composite carrier containing ZSM-5, beta zeolite and a binder;

[0026] ii) preparing an impregnation aqueous solution containing a chelating agent, an ethylene glycol oligomer, citric acid and a Pd source as an impregnation solution;

[0027] iii) contacting the impregnation aqueous solution with the composite support through impregnation, followed by aging, and then drying the solid under an inert atmosphere, calcining under a low oxygen content inert atmosphere, and then reducing;

[0028] The oxygen content in the low-oxygen inert atmosphere is less than 10% by volume, preferably less than 5% by volume.

[0029] In the present invention, the conditions for the immersion contacting can be selected in a wide range. According to a preferred embodiment of the present invention, the immersion temperature is 10 to 80°C.

[0030] The present invention has no special requirements on the impregnation contact method, and various impregnation contact methods can be used. According to a preferred embodiment of the present invention, the composite carrier is impregnated by a spraying method.

[0031] In the present invention, aging is to maintain the immersion contact for a period of time. According to a preferred embodiment of the present invention, the aging time is 0.5 to 24 hours.

[0032] In the present invention, the drying conditions can be selected in a wide range, and commonly used drying conditions can be used in the present invention. The preferred drying temperature for the present invention is 30 to 200°C, preferably 110-120°C.

[0033] In the present invention, the range of roasting conditions is relatively wide. The preferred roasting conditions for the present invention include: a temperature of 300 to 600° C., and a roasting time determined according to needs. For the present invention, the preferred roasting time is 0.5 to 24 hours.

[0034] In the present invention, the reduction conditions can be selected in a wide range. The preferred reduction conditions for the present invention include: the TPR hydrogen atmosphere reduction peak temperature of the catalyst before reduction is lower than 100°C, preferably 40-50°C.

[0035] The following exemplary description, but not limiting the scope of the present invention, includes the following reduction conditions: the reducing agent is selected from one or more of hydrazine hydrate, sodium formate, and formaldehyde, and the reduction temperature is lower than 100°C, preferably 20-100°C.

[0036] In the present invention, the dry inert atmosphere can be various inert gas atmospheres. For the present invention, the dry inert atmosphere is preferably one or more of a nitrogen atmosphere and an argon atmosphere, preferably a nitrogen atmosphere.

[0037] In the present invention, the oxygen content in the low oxygen-containing inert atmosphere for calcination is preferably 0.1 to 5% by volume, and the inert gas content is 95 to 99.9% by volume; any inert gas can be used in the present invention. For the present invention, preferably, the inert gas is one or more of nitrogen and argon.

[0038] In the present invention, the optional range of types of chelating agents is relatively wide. For the present invention, the chelating agent is preferably selected from one or more of 1-hydroxyethylidene-1,1-diphosphonic acid, tetrasodium hydroxyethylidene diphosphonic acid (tetrasodium HEDP), aminotri(methylenephosphonic acid) (ATMPA), and ethylenediaminetetramethylenephosphonic acid (EDTMP), preferably 1-hydroxyethylidene-1,1-diphosphonic acid (HEDPA) and / or tetrasodium hydroxyethylidene diphosphonic acid (tetrasodium HEDP).

[0039] In the present invention, the range of ethylene glycol oligomers available for selection is relatively wide. For the present invention, the weight average molecular weight of the ethylene glycol oligomer is preferably 200-600.

[0040] According to one embodiment of the present invention, the ethylene glycol oligomer is polyethylene glycol.

[0041] In the present invention, the composition of the impregnation liquid can be selected in a wide range. According to the present invention, the content of the chelating agent is preferably 0.01 to 5 grams, preferably 0.5 to 2 grams, per 100 milliliters of the impregnation liquid.

[0042] According to a preferred embodiment of the present invention, in every 100 ml of the impregnation solution, the contents of ethylene glycol oligomer and citric acid are 0.2 to 5 grams respectively.

[0043] According to a preferred embodiment of the present invention, the impregnation contact is an equal volume impregnation contact.

[0044] In the present invention, there is no special requirement for the preparation method of the composite carrier. According to a preferred embodiment of the present invention, the preparation method of the composite carrier includes:

[0045] (1) mixing a binder source, ZSM-5 powder, β-zeolite powder and an additive to obtain a mixture I;

[0046] (2) adding the mixture I to an acidic aqueous solution containing rare earth nitrate; kneading, forming, drying and calcining.

[0047] According to a preferred embodiment of the present invention, a method for preparing a composite carrier comprises: (1) firstly mixing a binder, ZSM-5 powder, β zeolite powder and an additive to obtain a mixture I; (2) adding the mixture I to an acidic aqueous solution containing 1% to 6% by weight, wherein the weight ratio of the mixture I to the acidic aqueous solution is 100:5 to 100:75, preferably 100:50 to 100:70, kneading and extruding, drying, and calcining at 450 to 650°C for 0.5 to 24 hours to obtain a catalyst composite carrier.

[0048] According to a preferred embodiment of the present invention, preferably, the binder is calculated as alumina, and the mass ratio of the binder, ZSM-5 powder, β zeolite powder and additive is 1:(3-10):(0.4-3.5):(0.1-0.4).

[0049] According to a preferred embodiment of the present invention, the acidic aqueous solution preferably further contains alkaline earth nitrate. The alkaline earth nitrate is calculated as alkaline earth oxide, and the acidic aqueous solution contains 1% to 6% of the acidic aqueous solution and 1% to 2% of the alkaline earth oxide.

[0050] According to a preferred embodiment of the present invention, the calcination conditions include: a temperature of 450 to 650° C. and a time of 0.5 to 24 hours.

[0051] In the present invention, both ZSM-5 powder and β zeolite powder can be used in the present invention. In the present invention, the preferred ZSM-5 powder is hydrogen type, SiO 2 / Al 2 O 3 The molar ratio is 20-200.

[0052] According to a preferred embodiment of the present invention, the β zeolite powder is hydrogen type, SiO 2 / Al 2 O 3 The molar ratio is 20-200.

[0053] In the present invention, the optional range of types of binder sources is relatively wide, and commonly used binder sources can be used in the present invention. For the present invention, the binder source is preferably selected from at least one of silica sol, water glass, pseudo-boehmite, white carbon black, and aluminum sol.

[0054] In the present invention, the optional range of the types of auxiliary agents is relatively wide, and commonly used auxiliary agents can be used in the present invention. For the present invention, the auxiliary agent is preferably selected from at least one of methyl cellulose, field blue powder, polyethylene glycol, calcium nitrate, potassium nitrate and hydroxymethyl cellulose.

[0055] In the present invention, the acidic aqueous solution has a wide range of optional types, and commonly used acidic aqueous solutions can be used in the present invention. For the present invention, the acidic substance in the acidic aqueous solution is preferably selected from at least one of nitric acid, phosphoric acid, acetic acid, citric acid and tartaric acid.

[0056] According to a preferred embodiment of the present invention, ZSM-5 powder is hydrogen type, SiO 2 / Al 2 O 3 50~300, β zeolite powder is hydrogen type, SiO 2 / Al 2 O 3 is 20 to 200; the adhesive is selected from at least one of silica sol, water glass, pseudo-boehmite, white carbon black, and aluminum sol; the auxiliary agent is selected from at least one of methyl cellulose, Tianqing powder and polyethylene glycol, calcium nitrate, potassium nitrate, and hydroxymethyl cellulose.

[0057] According to a preferred embodiment of the present invention, the acidic aqueous solution is selected from at least one of nitric acid, phosphoric acid, acetic acid, citric acid and tartaric acid.

[0058] The present invention provides a hydrocracking catalyst for refining aromatic-rich fraction oil, cracking C 9 +, ethylene tar, coal tar, catalytic light diesel or reforming C 9 + Application in hydrocracking.

[0059] The present invention provides a method for preparing BTX by hydrocracking of aromatic-rich fraction oil, which comprises: hydrocracking refined aromatic-rich light cracked fraction oil in the presence of a catalyst under hydrocracking reaction conditions, wherein the catalyst contains the hydrocracking catalyst of the present invention.

[0060] In the present invention, the optional range of hydrocracking conditions is relatively wide. According to a preferred embodiment of the present invention, the hydrocracking conditions include: a pressure of 2 to 8 MPa.

[0061] In the present invention, the hydrocracking conditions can be selected in a wide range. According to a preferred embodiment of the present invention, the hydrocracking conditions include: a fresh feed space velocity of 0.6 to 4.0 h -1 .

[0062] In the present invention, the optional range of hydrocracking conditions is relatively wide. According to a preferred embodiment of the present invention, the hydrocracking conditions include: a temperature of 300 to 500°C.

[0063] In the present invention, the optional range of hydrocracking conditions is relatively wide. According to a preferred embodiment of the present invention, the hydrocracking conditions include: a hydrogen-to-oil volume ratio of 500 to 2000.

[0064] According to a preferred embodiment of the present invention, a raw material having an initial boiling point of 85 to 170°C, a final boiling point of 220 to 280°C, a sulfur content of <50ug / mL, a nitrogen content of <10ug / mL, and a monocyclic aromatic hydrocarbon content of >90wt% is used as a raw material, and is contacted with a hydrocracking catalyst under a hydrogen atmosphere for hydrocracking; the hydrocracking conditions include: a reactor inlet temperature of 300 to 500°C, a fresh feed space velocity of 0.6 to 4.0h -1 , hydrogen-oil volume ratio 500-2000, pressure 2-8MPa. The hydrocracking catalyst of the present invention can be used for hydrocracking of aromatic-rich distillate oil with a final boiling point of less than 280°C and a monocyclic aromatic hydrocarbon content of more than 90% by weight, and the BTX liquid phase yield can be greater than 55%, with good hydrocracking effect. After 2000 hours online, the BTX yield in the liquid phase product is greater than 55%, wherein the toluene content is greater than 50%.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] The hydrocracking catalyst provided by the invention has high stability.

[0067] The preparation method of the hydrocracking catalyst of the present invention comprises the following steps: adding a chelating agent, citric acid and ethylene glycol oligomers during the impregnation process, drying in an inert atmosphere, and calcining in a low oxygen-containing inert atmosphere, while reducing the TPR hydrogen atmosphere reduction temperature of the catalyst. The catalyst has strong stability, a long catalyst operation cycle, and a high BTX yield.

[0068] The hydrocracking catalyst provided by the present invention is used for preparing BTX from refined light aromatic-rich distillate oil with high stability, which solves the problem that refined light aromatic-rich cracking distillate oil cannot be used with high added value, and enables low added value light aromatic-rich cracking distillate oil to be efficiently converted into high added value BTX. For refined light aromatic-rich cracking distillate oil with an initial boiling point of 85-170°C, a final boiling point of 220-280°C, a total aromatic content of more than 90%, a sulfur content of less than 50ug / mL, and a nitrogen content of less than 10ug / mL; the hydrocracking reaction conditions are: a reactor inlet temperature of 380-480°C, a fresh feed space velocity of 0.6-4.0h -1 , hydrogen-to-oil volume ratio of 500-2000, pressure 2-8MPa, the yield of total liquid products of initial hydrocracking products is greater than 80%, the yield of liquid product BTX is greater than 55%, after 2000 hours online, the catalyst activity decreases slightly, the yield of total liquid products is greater than 80%, of which the yield of liquid product BTX is greater than 55%, and the toluene content in BTX is greater than 50%, achieving good technical results. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 The XRD spectrum of the composite support and the hydrocracking catalyst of Example 1 of the present invention;

[0070] Figure 2 The material distribution-online time diagram of the evaluation results of the hydrocracking catalyst of Example 1 of the present invention;

[0071] Figure 3 The XRD spectrum of the composite support and the hydrocracking catalyst of Example 2 of the present invention;

[0072] Figure 4 The XRD spectrum of the composite support and the hydrocracking catalyst of Comparative Example 2 of the present invention; DETAILED DESCRIPTION

[0073] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0074] The present invention will be further described below by way of examples, but these examples are not intended to limit the scope of the present invention.

[0075] In the present invention, the dispersion test method of the active component Pd is the hydrogen-oxygen titration method.

[0076] R=[Pd] / [Pd] 总 =(2 / 3×V 0 ×N A ×1 / 22400W / P) / (N A ×1 / M)

[0077] Where: R-----dispersion of Pd;

[0078] [Pd]-----Number of nickel atoms on the surface;

[0079] [Pd] 总 -----Total number of nickel atoms;

[0080] V 0 -----Hydrogen titration, mL;

[0081] N A -----Avogadro constant (6.023) × 10 23 ;

[0082] W-----style mass, g;

[0083] P-----mass fraction of Pd in ​​the sample, %;

[0084] M-----The atomic weight of Pd is 106.4.

[0085] In the present invention, the test method for TPR hydrogen atmosphere reduction is hydrogen-oxygen titration method.

[0086] In the present invention, the liquid phase product yield calculation method is:

[0087] Liquid product yield = W 液体产物 / W 原料 ,

[0088] W 液体产物 -----The weight of the liquid phase reaction product after 24 hours of online reaction, g;

[0089] W 原料 ----Feed amount of light aromatic-rich cracking distillate oil raw material refined online for 24 hours, grams.

[0090] In the present invention, the reduction peak temperature of the active component Pd is determined by a TPR programmed temperature reduction method, in which a hydrogen atmosphere is used for reduction, the heating rate is 10°C / min, and the temperature is raised to 800°C.

[0091] The amount of carbon deposits was measured using the Multi EA2000 carbon-sulfur analyzer from Jena, Germany. The catalyst was first dried at 150°C for 2 hours, and then tested at a combustion temperature of 900°C with 99.995% pure oxygen as carrier gas. The standard substance used was spectrally pure CaCO powder with a carbon mass fraction of 12.00%.

[0092] In the present invention, the water absorption rate of the carrier is determined by soaking 5 grams of the carrier in pure water for 5 minutes, then taking it out and placing it in a filter for 2 minutes to remove the moisture on the outer surface, that is, the weight of the carrier after absorbing water.

[0093] Water absorption rate = (W 吸水后载体 -W 载体 ) / W 载体 ×100%

[0094] [Example 1]

[0095] Select hydrogen SiO 2 / Al 2 O 3 650g ZSM-5 molecular sieve powder, hydrogen SiO 2 / Al 2 O 3 250 g of 40 β molecular sieve powder, 100 g of pseudo-boehmite containing alumina, 15 g of methyl cellulose and 15 g of Tianqing powder are mixed evenly for use; then 7 g of nitric acid and 5 g of citric acid are added to 600 g of water and dissolved evenly, the solution is poured into the above mixed powder and kneaded for 35 minutes, extruded into strips, left for 12 hours, dried at 110°C for 6 hours, and then placed in a muffle furnace at 600°C for 5 hours to obtain a composite carrier with a water absorption rate of 99.1%.

[0096] Soluble metal salt precursors were used to prepare an impregnation solution containing 1.2 g of Pd, and the volume of the solution was controlled at 170 ml. 1.5 g of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDPA), 1.5 g of polyethylene glycol (molecular weight 200), and 2.0 g of citric acid were added to the impregnation solution and stirred to dissolve evenly. 198.8 g of the composite carrier was loaded with an equal volume of the impregnation solution on the composite carrier by a rotary pan spraying method. The impregnation temperature was 20°C, and the catalyst was aged for 16 hours, dried at 110°C in a nitrogen atmosphere for 4 hours, and calcined at 400°C in a nitrogen atmosphere containing 1.0 volume% oxygen for 6 hours to obtain the catalyst. The catalyst was reduced at 90°C for 8 hours with a 5% sodium formate aqueous solution. The composite carrier, catalyst preparation conditions, and catalyst carbon deposition are shown in Tables 1, 2, and 3.

[0097] The XRD patterns of the composite support and catalyst are shown in Figure 1 , Figure 1This indicates that the carrier does not show characteristic peaks of the active components after loading the active components, indicating that the active components have small particle size and good dispersion effect on the carrier; the dispersion degree of the reduced catalyst Pd is 23.5%, indicating that the active components are well dispersed, easy to reduce, and the catalyst activity is high.

[0098] Evaluation raw materials: Refined light aromatic cracking raw materials: distillation range 165-255℃, sulfur content = 0.8ppm, nitrogen content = 0.6ppm;

[0099] Raw material composition: non-aromatic 3.81wt%; alkylbenzene 40.57wt%; indanes 23.76wt%;

[0100] Tetralins 29.25wt%; naphthalenes 2.30wt%; benzene 0.31wt%.

[0101] Reaction conditions: reactor inlet temperature 330°C, fresh feed space velocity 1.8h -1 , hydrogen-oil volume ratio 800, pressure 4.0MPa.

[0102] The evaluation results are shown in Table 4, and the material distribution-online time spectrum of the evaluation results of the hydrocracking catalyst is shown in Figure Figure 2 , Figure 2 This indicates that the catalyst has good stability and high BTX yield.

[0103] [Example 2]

[0104] Select hydrogen SiO 2 / Al 2 O 3 500g ZSM-5 molecular sieve powder, hydrogen SiO 2 / Al 2 O 3 400 g of β molecular sieve powder with a viscosity of 20, 100 g of pseudo-boehmite containing alumina, 15 g of methyl cellulose and 15 g of Tianqing powder are mixed evenly for use; then 7 g of nitric acid and 5 g of citric acid are added to 600 g of water and dissolved evenly, the solution is poured into the above mixed powder and kneaded for 35 minutes, extruded into strips, left for 12 hours, dried at 110°C for 6 hours, and then placed in a muffle furnace at 600°C for 5 hours to obtain a composite carrier with a water absorption rate of 100.3%.

[0105] Soluble metal salt precursors were used to prepare an impregnation solution containing 1.2 g of Pd, and the volume of the solution was controlled at 170 ml. 1.3 g of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDPA), 1.5 g of polyethylene glycol (molecular weight 200), and 2.0 g of citric acid were added to the impregnation solution and stirred to dissolve evenly. 198.8 g of the composite carrier was taken and an equal volume of the impregnation solution was loaded on the composite carrier by a rotary pan spraying method. The impregnation temperature was 60°C, and the catalyst was aged for 16 hours, dried at 110°C in a nitrogen atmosphere for 4 hours, and calcined at 400°C in a nitrogen atmosphere containing 2.0% oxygen for 6 hours to obtain the catalyst. The reduced catalyst was obtained by reducing with a 5% sodium formate aqueous solution at 90°C for 8 hours. The composite carrier, catalyst preparation conditions, and catalyst carbon deposition are shown in Tables 1, 2, and 3.

[0106] The XRD patterns of the composite support and catalyst are shown in Figure 3 , Figure 3 This indicates that the carrier does not show the characteristic peak of the active component after loading the active component, indicating that the active component has a small particle size on the carrier and a good dispersion effect. The dispersion of the reduced catalyst Pd is 22.8%, indicating that the active component is well dispersed, easy to reduce, and the catalyst activity is high.

[0107] The evaluation materials and conditions were consistent with those in Example 1. The evaluation results are shown in Table 4.

[0108] [Example 3]

[0109] Select hydrogen SiO 2 / Al 2 O 3 800g ZSM-5 molecular sieve powder, hydrogen-type SiO 2 / Al 2 O 3 100 g of β molecular sieve powder with a pH of 30, 100 g of pseudo-boehmite containing alumina, 15 g each of methyl cellulose and Tianqing powder are mixed evenly for use; then 7 g of nitric acid and 5 g of citric acid are added to 600 g of water and dissolved evenly, the solution is poured into the above mixed powder and kneaded for 35 minutes, extruded into strips, left for 12 hours, dried at 110°C for 8 hours, and then placed in a muffle furnace at 600°C for 4 hours to obtain a composite carrier with a water absorption rate of 100.8%.

[0110] Soluble metal salt precursors were used to prepare an impregnation solution containing 3.0 g of Pd, and the volume of the solution was controlled at 170 ml. 1.5 g of tetrasodium hydroxyethylidene diphosphonate (tetrasodium HEDP), 2.0 g of polyethylene glycol (molecular weight 200), and 6.0 g of citric acid were added to the impregnation solution and stirred to dissolve evenly. 197.0 g of the composite carrier was loaded with an equal volume of the impregnation solution on the composite carrier by a rotary pan spraying method. The impregnation temperature was 60°C, aged for 16 hours, dried at 110°C in a nitrogen atmosphere for 4 hours, calcined at 500°C in an argon atmosphere containing 3.0% oxygen for 6 hours to obtain the catalyst, and reduced with a hydrazine hydrate solution at 20°C for 4 hours to obtain the reduced catalyst. The composite carrier, catalyst preparation conditions and catalyst carbon deposition are shown in Tables 1, 2 and 3.

[0111] XRD patterns of composite supports and catalysts Figure 1 and Figure 3 Similarly, it means that the carrier does not show the characteristic peak of the active component after loading the active component, indicating that the active component has a small particle size and good dispersion effect on the carrier. The dispersion of the reduced catalyst Pd is 25.8%, indicating that the active component is well dispersed, easy to reduce, and the catalyst activity is high.

[0112] The evaluation materials and conditions were consistent with those in Example 1. The evaluation results are shown in Table 4.

[0113] [Example 4]

[0114] Select hydrogen SiO 2 / Al 2 O 3 840 g of ZSM-5 molecular sieve powder, hydrogen-type SiO 2 / Al 2 O 3 60 grams of 40 β molecular sieve powder, 100 grams of pseudo-boehmite containing alumina, 15 grams of methyl cellulose and Tianqing powder are mixed evenly for use; then 5 grams of nitric acid and 6 grams of citric acid are added to 600 grams of water to dissolve evenly, the solution is poured into the above mixed powder and kneaded for 35 minutes, extruded into strips, left for 12 hours, dried at 120°C for 4 hours, and then placed in a muffle furnace at 550°C for 8 hours to obtain a composite carrier with a water absorption rate of 99.6%.

[0115] Soluble metal salt precursors were used to prepare an impregnation solution containing 2.0 g of Pd, and the solution volume was controlled at 170 ml. 1.0 g of aminotrimethylphosphonic acid (ATMPA), 1.0 g of ethylenediaminetetramethylenephosphonic acid (EDTMP), 3.0 g of polyethylene glycol (molecular weight 400), and 3.0 g of citric acid were added to the impregnation solution and stirred to dissolve evenly. 198.0 g of the composite carrier was taken and an equal volume of the impregnation solution was loaded on the composite carrier by a rotary pan spraying method. The impregnation temperature was 60°C, aged for 16 hours, dried at 110°C in a nitrogen atmosphere for 4 hours, calcined at 450°C in a nitrogen atmosphere containing 1.5% oxygen for 8 hours to obtain the catalyst, and reduced at 90°C for 8 hours with a 10% formaldehyde aqueous solution to obtain the reduced catalyst. The composite carrier, catalyst preparation conditions and catalyst carbon deposition are shown in Tables 1, 2 and 3.

[0116] XRD patterns of composite supports and catalysts Figure 1 and Figure 3 Similarly, it means that the carrier does not show the characteristic peak of the active component after loading the active component, indicating that the active component has a small particle size and good dispersion effect on the carrier. The dispersion of the reduced catalyst Pd is 35.0%, indicating that the active component is well dispersed, easy to reduce, and the catalyst activity is high.

[0117] The evaluation materials and conditions were consistent with those in Example 1. The evaluation results are shown in Table 4.

[0118] [Example 5]

[0119] Select hydrogen SiO 2 / Al 2 O 3 700g of ZSM-5 molecular sieve powder, hydrogen-type SiO 2 / Al 2 O 3 200 grams of β molecular sieve powder with a density of 150, 100 grams of silica sol containing silicon oxide, 15 grams of methyl cellulose and 15 grams of Tianqing powder are mixed evenly for use; then 7 grams of nitric acid and 5 grams of citric acid are added to 600 grams of water and dissolved evenly, the solution is poured into the above mixed powder and kneaded for 35 minutes, extruded into strips, left for 12 hours, dried at 130°C for 5 hours, and then placed in a muffle furnace at 500°C for 24 hours to obtain a composite carrier with a water absorption rate of 100.9%.

[0120] Soluble metal salt precursors were used to prepare an impregnation solution containing 0.2 g of Pd, and the volume of the solution was controlled at 170 ml. 2.0 g of tetrasodium hydroxyethylidene diphosphonate (tetrasodium HEDP), 0.5 g of polyethylene glycol (molecular weight 400), and 0.5 g of citric acid were added to the impregnation solution and stirred to dissolve evenly. 199.8 g of the composite carrier was loaded with an equal volume of the impregnation solution on the composite carrier by a rotary pan spraying method. The impregnation temperature was 60°C, aged for 16 hours, dried at 110°C in a nitrogen atmosphere for 4 hours, calcined at 400°C in a nitrogen atmosphere containing 4.0% oxygen for 4 hours to obtain the catalyst, and reduced at 90°C for 8 hours with a 5% sodium formate aqueous solution to obtain the reduced catalyst. The composite carrier, catalyst preparation conditions and catalyst carbon deposition are shown in Tables 1, 2 and 3.

[0121] XRD patterns of composite supports and catalysts Figure 1 and Figure 3 Similarly, it means that the carrier does not show the characteristic peak of the active component after loading the active component, indicating that the active component has a small particle size and good dispersion effect on the carrier. The dispersion of the reduced catalyst Pd is 22.8%, indicating that the active component is well dispersed, easy to reduce, and the catalyst activity is high.

[0122] The evaluation materials and conditions were consistent with those in Example 1. The evaluation results are shown in Table 4.

[0123] [Example 6]

[0124] Select hydrogen SiO 2 / Al 2 O 3 750g ZSM-5 molecular sieve powder, hydrogen SiO 2 / Al 2 O 3 150 g of β molecular sieve powder with a density of 200, aluminum sol containing 100 g of alumina, 15 g of methyl cellulose and 15 g of Tianqing powder are mixed evenly for use; then 7 g of nitric acid and 5 g of citric acid are added to 600 g of water and dissolved evenly, the solution is poured into the above mixed powder and kneaded for 35 minutes, extruded into strips, left for 12 hours, dried at 200°C for 2 hours, and placed in a muffle furnace for calcination at 550°C for 6 hours to obtain a composite carrier with a water absorption rate of 99.7%.

[0125] Soluble metal salt precursors were used to prepare an impregnation solution containing 0.8 g of Pd, and the volume of the solution was controlled at 170 ml. 0.8 g of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDPA), 0.7 g of ethylenediaminetetramethylenephosphonic acid (EDTMP), 6.0 g of polyethylene glycol (molecular weight 400), and 0.5 g of citric acid were added to the impregnation solution and stirred to dissolve evenly. 199.2 g of the composite carrier was taken and an equal volume of the impregnation solution was loaded on the composite carrier by a rotary pan spraying method. The impregnation temperature was 60°C, and the catalyst was aged for 16 hours, dried at 110°C in a nitrogen atmosphere for 4 hours, and calcined at 600°C in an argon atmosphere containing 0.5% oxygen for 6 hours to obtain the catalyst. The reduced catalyst was obtained by reducing with a 5% sodium formate aqueous solution at 90°C for 8 hours. The composite carrier, catalyst preparation conditions and catalyst carbon deposition amount are shown in Tables 1, 2 and 3.

[0126] XRD patterns of composite supports and catalysts Figure 1 and Figure 3 Similarly, it means that the carrier does not show the characteristic peak of the active component after loading the active component, indicating that the active component has a small particle size and good dispersion effect on the carrier. The dispersion of the reduced catalyst Pd is 32.0%, indicating that the active component is well dispersed, easy to reduce, and the catalyst activity is high.

[0127] The evaluation materials and conditions were consistent with those in Example 1. The evaluation results are shown in Table 4.

[0128] [Example 7]

[0129] Select hydrogen SiO 2 / Al 2 O 3 650g ZSM-5 molecular sieve powder, hydrogen SiO 2 / Al 2 O 3 200 grams of β molecular sieve powder with a purity of 100, 150 grams of white carbon black containing silicon oxide, 15 grams of methyl cellulose and 15 grams of Tianqing powder are mixed evenly for use; then 7 grams of nitric acid and 5 grams of citric acid are added to 600 grams of water and dissolved evenly, the solution is poured into the above mixed powder and kneaded for 35 minutes, extruded into strips, left for 12 hours, dried at 110°C for 8 hours, and placed in a muffle furnace at 700°C for 2 hours to obtain a composite carrier with a water absorption rate of 101.2%.

[0130] Soluble metal salt precursors were used to prepare an impregnation solution containing 1.2 g of Pd, and the volume of the solution was controlled at 170 ml. 1.2 g of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDPA), 1.3 g of tetrasodium hydroxyethylidene diphosphonate (HEDP tetrasodium), 3.0 g of polyethylene glycol (molecular weight 600), and 1.5 g of citric acid were added to the impregnation solution and stirred to dissolve evenly. 198.8 g of the composite carrier was loaded with an equal volume of the impregnation solution on the composite carrier by a rotary pan spraying method. The impregnation temperature was 60°C, aged for 16 hours, dried at 110°C in a nitrogen atmosphere for 4 hours, calcined at 450°C in a nitrogen atmosphere containing 0.8% oxygen for 6 hours to obtain the catalyst, and reduced at 90°C for 8 hours with a 5% sodium formate aqueous solution to obtain the reduced catalyst. The composite carrier, catalyst preparation conditions and catalyst carbon deposition are shown in Tables 1, 2 and 3.

[0131] XRD patterns of composite supports and catalysts Figure 1 and Figure 3 Similarly, it means that the carrier does not show the characteristic peak of the active component after loading the active component, indicating that the active component has a small particle size and good dispersion effect on the carrier. The dispersion of the reduced catalyst Pd is 23.5%, indicating that the active component is well dispersed, easy to reduce, and the catalyst activity is high.

[0132] The evaluation materials and conditions were consistent with those in Example 1. The evaluation results are shown in Table 4.

[0133] [Example 8]

[0134] Select hydrogen SiO 2 / Al 2 O 3 500g ZSM-5 molecular sieve powder, hydrogen SiO 2 / Al 2 O 3 450 g of β molecular sieve powder with a concentration of 50, 50 g of water glass containing silicon oxide, 15 g of methyl cellulose and 15 g of Tianqing powder are mixed evenly for use; then 7 g of nitric acid and 5 g of citric acid are added to 600 g of water and dissolved evenly, the solution is poured into the above mixed powder and kneaded for 35 minutes, extruded into strips, left for 12 hours, dried at 110°C for 8 hours, and then placed in a muffle furnace at 600°C for 4 hours to obtain a composite carrier with a water absorption rate of 99.9%.

[0135] Soluble metal salt precursors were used to prepare an impregnation solution containing 1.2 g of Pd, and the volume of the solution was controlled at 170 ml. 1.2 g of tetrasodium hydroxyethylidene diphosphonate (tetrasodium HEDP), 2.0 g of aminotrimethylphosphonic acid (ATMPA), 2.0 g of polyethylene glycol (molecular weight 600), and 2.0 g of citric acid were added to the impregnation solution and stirred to dissolve evenly. 198.8 g of the composite carrier was loaded with an equal volume of the impregnation solution on the composite carrier by a rotary pan spraying method. The impregnation temperature was 60°C, aged for 16 hours, dried at 110°C in a nitrogen atmosphere for 4 hours, calcined at 550°C in a nitrogen atmosphere containing 1.0% oxygen for 6 hours to obtain the catalyst, and reduced at 90°C for 8 hours with a 5% sodium formate aqueous solution to obtain the reduced catalyst. The composite carrier, catalyst preparation conditions and catalyst carbon deposition are shown in Tables 1, 2 and 3.

[0136] XRD patterns of composite supports and catalysts Figure 1 and Figure 3 Similarly, it means that the carrier does not show the characteristic peak of the active component after loading the active component, indicating that the active component has a small particle size and good dispersion effect on the carrier. The dispersion of the reduced catalyst Pd is 22.0%, indicating that the active component is well dispersed, easy to reduce, and the catalyst activity is high.

[0137] The evaluation materials and conditions were consistent with those in Example 1. The evaluation results are shown in Table 4.

[0138] [Example 9]

[0139] Select hydrogen SiO 2 / Al 2 O 3 500g ZSM-5 molecular sieve powder, hydrogen SiO 2 / Al 2 O 3 400 g of β molecular sieve powder with a pH of 50, 100 g of pseudo-boehmite containing alumina, 15 g each of methyl cellulose and Tianqing powder are mixed evenly for use; then 7 g of nitric acid and 5 g of citric acid are added to 600 g of water and dissolved evenly, the solution is poured into the above mixed powder and kneaded for 35 minutes, extruded into strips, left for 12 hours, dried at 110°C for 24 hours, and then placed in a muffle furnace at 600°C for 4 hours to obtain a composite carrier with a water absorption rate of 100.9%.

[0140] Soluble metal salt precursors were used to prepare an impregnation solution containing 1.2 g of Pd, and the solution volume was controlled at 170 ml. 0.8 g of tetrasodium hydroxymethylene diphosphonate (tetrasodium HEDP), 0.6 g of ethylenediamine tetramethylene phosphonic acid (EDTMP), 4.5 g of polyethylene glycol (molecular weight 300), and 3.5 g of citric acid were added to the impregnation solution and stirred to dissolve evenly. 198.8 g of the composite carrier was loaded with an equal volume of the impregnation solution on the composite carrier by a rotary pan spraying method. The impregnation temperature was 60°C, aged for 16 hours, dried at 110°C in a nitrogen atmosphere for 4 hours, calcined at 300°C in a nitrogen atmosphere containing 0.2% oxygen for 6 hours to obtain the catalyst, and reduced at 90°C for 8 hours with a 5% sodium formate aqueous solution to obtain the reduced catalyst. The composite carrier, catalyst preparation conditions and catalyst carbon deposition are shown in Tables 1, 2 and 3.

[0141] XRD patterns of composite supports and catalysts Figure 1 and Figure 3 Similarly, it means that the carrier does not show the characteristic peak of the active component after loading the active component, indicating that the active component has a small particle size and good dispersion effect on the carrier. The dispersion of the reduced catalyst Pd is 20.1%, indicating that the active component is well dispersed, easy to reduce, and the catalyst activity is high.

[0142] The evaluation materials and conditions were consistent with those in Example 1. The evaluation results are shown in Table 4.

[0143] [Example 10]

[0144] Select hydrogen SiO 2 / Al 2 O 3 750g ZSM-5 molecular sieve powder, hydrogen SiO 2 / Al 2 O 3 170 g of β molecular sieve powder with a temperature of 90°C, 80 g of pseudo-boehmite containing alumina, 15 g of methyl cellulose and 15 g of Tianqing powder are mixed evenly for use; then 7 g of nitric acid and 5 g of citric acid are added to 600 g of water and dissolved evenly, the solution is poured into the above mixed powder and kneaded for 35 minutes, extruded into strips, left for 12 hours, dried at 120°C for 4 hours, and then placed in a muffle furnace at 600°C for 4 hours to obtain a composite carrier with a water absorption rate of 99.3%.

[0145] Soluble metal salt precursors were used to prepare an impregnation solution containing 1.2 g of Pd, and the volume of the solution was controlled at 170 ml. 0.5 g of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDPA), 0.6 g of aminotrimethylphosphonic acid (ATMPA), 1.6 g of polyethylene glycol (molecular weight 300), and 0.6 g of citric acid were added to the impregnation solution and stirred to dissolve evenly. 198.8 g of the composite carrier was loaded with an equal volume of the impregnation solution on the composite carrier by a rotary pan spraying method. The impregnation temperature was 60°C, aged for 16 hours, dried at 110°C in a nitrogen atmosphere for 4 hours, calcined at 500°C in a nitrogen atmosphere containing 1.2% oxygen for 3 hours to obtain the catalyst, and reduced at 100°C for 6 hours with a 5% sodium formate aqueous solution to obtain the reduced catalyst. The composite carrier, catalyst preparation conditions and catalyst carbon deposition are shown in Tables 1, 2 and 3.

[0146] XRD patterns of composite supports and catalysts Figure 1 and Figure 3 Similarly, it means that the carrier does not show the characteristic peak of the active component after loading the active component, indicating that the active component has a small particle size and good dispersion effect on the carrier. The dispersion of the reduced catalyst Pd is 23.2%, indicating that the active component is well dispersed, easy to reduce, and the catalyst activity is high.

[0147] The evaluation materials and conditions were consistent with those in Example 1. The evaluation results are shown in Table 4.

[0148] [Comparative Example 1]

[0149] Select hydrogen SiO 2 / Al 2 O 3 650g ZSM-5 molecular sieve powder, hydrogen SiO 2 / Al 2 O 3 250 g of 40 β molecular sieve powder, 100 g of pseudo-boehmite containing alumina, 15 g of methyl cellulose and 15 g of Tianqing powder are mixed evenly for use; then 7 g of nitric acid and 5 g of citric acid are added to 600 g of water and dissolved evenly, the solution is poured into the above mixed powder and kneaded for 35 minutes, extruded into strips, left for 12 hours, dried at 110°C for 6 hours, and then placed in a muffle furnace at 600°C for 5 hours to obtain a composite carrier with a water absorption rate of 99.1%.

[0150] Soluble metal salt precursors were used to prepare an impregnation solution containing 1.2 g of Pd, and the solution volume was controlled at 170 ml. 1.5 g of polyethylene glycol (molecular weight 200) and 2.0 g of citric acid were added to the impregnation solution and stirred to dissolve evenly. 198.8 g of the composite carrier was taken and an equal volume of the impregnation solution was loaded on the composite carrier by a rotary pan spraying method. The impregnation temperature was 20°C, and the catalyst was aged for 16 hours, dried at 110°C in a nitrogen atmosphere for 4 hours, and calcined at 400°C in an air atmosphere for 6 hours to obtain the catalyst. The reduced catalyst was obtained by reducing with a 5% sodium formate aqueous solution at 90°C for 8 hours. The composite carrier, catalyst preparation conditions and catalyst carbon deposition amount are shown in Tables 1, 2 and 3.

[0151] The dispersion degree of Pd in ​​the reduced catalyst was 7.8%.

[0152] The evaluation materials and conditions were consistent with those in Example 1. The evaluation results are shown in Table 4.

[0153] [Comparative Example 2]

[0154] Select hydrogen SiO 2 / Al 2 O 3 900 g of ZSM-5 molecular sieve powder with a pH of 25, 100 g of pseudo-boehmite containing alumina, 15 g of methyl cellulose and 15 g of Tianqing powder are mixed evenly for use; then 7 g of nitric acid and 5 g of citric acid are added to 600 g of water and dissolved evenly, the solution is poured into the above mixed powder and kneaded for 35 minutes, extruded into strips, left for 12 hours, dried at 110°C for 6 hours, and then placed in a muffle furnace at 600°C for 5 hours to obtain a composite carrier with a water absorption rate of 99.1%.

[0155] Soluble metal salt precursors were used to prepare an impregnation solution containing 1.2 g of Pd, and the solution volume was controlled at 170 ml. 1.5 g of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDPA), 1.5 g of polyethylene glycol (molecular weight 200), and 2.0 g of citric acid were added to the impregnation solution and stirred to dissolve evenly. 198.8 g of the composite carrier was taken and the same volume of the impregnation solution was loaded on the composite carrier by a rotary pan spraying method. The impregnation temperature was 20°C, and the catalyst was aged for 16 hours, dried at 110°C in a nitrogen atmosphere for 4 hours, and calcined at 400°C in a nitrogen atmosphere containing 1.0% oxygen for 6 hours to obtain the catalyst. The catalyst was reduced at 90°C for 8 hours with a 5% sodium formate aqueous solution. The composite carrier, catalyst preparation conditions and catalyst carbon deposition are shown in Tables 1, 2 and 3.

[0156] The XRD patterns of the composite support and catalyst are shown in Figure 4 , Figure 4 This indicates that the carrier does not show the characteristic peak of the active component after loading the active component, indicating that the active component has a small particle size and good dispersion effect on the carrier. The dispersion degree of the reduced catalyst palladium is 6.9%.

[0157] The evaluation materials and conditions were consistent with those in Example 1. The evaluation results are shown in Table 4.

[0158] Table 1 Preparation conditions of composite carrier

[0159]

[0160]

[0161] Table 2 Catalyst preparation conditions, carbon deposition and Pd dispersion

[0162]

[0163] It can be seen from the results in Table 2 that the dispersion of the catalysts prepared in Examples 1-10 is much higher than that in the comparative examples, and the reduction temperature is also significantly lower than that in the comparative examples; this indicates that the catalysts prepared by the method of the present invention have the effects of high dispersion of active components and low reduction temperature.

[0164] Table 3 Addition amount of catalyst chelating agent and auxiliary agent

[0165]

[0166] Table 4 Catalyst evaluation results

[0167]

[0168]

[0169] Since the carrier adopts a suitable combination of ZSM-5 and β molecular sieve, and adopts the loading technology of the present invention, after loading the active components, the selective hydrocracking product is mainly BTX; and the toluene content in the product BTX of the present invention exceeds 50%, with obvious toluene selectivity. The carbon content on the catalyst surface is controlled by carbonization technology, and the stability of the catalyst is greatly improved for 2000 hours online.

[0170] 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 hydrocracking catalyst, characterized in that: The catalyst comprises the following components based on the total weight of the catalyst: a) 0.01% to 1.5% Pd; b) 50% to 90% ZSM-5; c) 5% to 50% beta zeolite; d) 5% to 20% binder; The amount of carbon deposited on the catalyst is 0.1% to 3% of the weight of the catalyst.

2. The catalyst according to claim 1, wherein The dispersion of the active component Pd is greater than 18%, preferably greater than 20%, preferably 20-35%; and / or The adhesive is selected from silicon dioxide and / or aluminum oxide; and / or ZSM-5 is hydrogen type, SiO2 / Al2O3 molar ratio is 20-200; and / or The beta zeolite is in the hydrogen form, and the SiO2 / Al2O3 molar ratio is 20 to 200; and / or and / or In the catalyst, by weight percentage, Pd is 0.1% to 1.5%, ZSM-5 is 55% to 85%, beta zeolite is 6% to 45%, and the binder content is 5% to 15%.

3. The method for preparing the catalyst according to claim 1 or 2, wherein: The method includes: i) preparing a composite carrier containing ZSM-5, beta zeolite and a binder; ii) preparing an impregnation aqueous solution containing a chelating agent, an ethylene glycol oligomer, citric acid and a Pd source as an impregnation solution; iii) contacting the impregnation aqueous solution with the composite support through impregnation, followed by aging, and then drying the solid under an inert atmosphere, calcining under a low oxygen content inert atmosphere, and then reducing; The oxygen content in the low-oxygen inert atmosphere is less than 10% by volume, preferably less than 5% by volume.

4. The preparation method according to claim 3, wherein Step iii), the conditions for the immersion contact include: The immersion temperature is 10 to 80°C; and / or Adopting a spraying method to impregnate onto the composite carrier; and / or The aging time is 0.5 to 24 hours.

5. The preparation method according to claim 3 or 4, wherein Step iii), Drying conditions include: a temperature of 30 to 200°C, preferably 110 to 120°C; and / or The calcination conditions include: a temperature of 300 to 600° C., and / or a time of 0.5 to 24 hours; and / or The reduction conditions include: the reducing agent is selected from one or more of hydrazine hydrate, sodium formate, and formaldehyde, and the reduction temperature is lower than 100°C, preferably 20-100°C, and preferably 40-50°C.

6. The preparation method according to any one of claims 3 to 5, wherein: Step iii), The dry inert atmosphere is one or more of a nitrogen atmosphere and an argon atmosphere, preferably a nitrogen atmosphere; and / or The oxygen content in the low oxygen-containing inert atmosphere for calcination is 0.1 to 5% by volume, and the inert gas content is 95 to 99.9% by volume; preferably, the inert gas is one or more of nitrogen and argon.

7. The preparation method according to any one of claims 3 to 6, wherein: The chelating agent is selected from one or more of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDPA), tetrasodium hydroxyethylidene diphosphonic acid (tetrasodium HEDP), aminotrimethylphosphonic acid (ATMPA), ethylenediaminetetramethylenephosphonic acid (EDTMP), preferably 1-hydroxyethylidene-1,1-diphosphonic acid (HEDPA) and / or tetrasodium hydroxyethylidene diphosphonic acid (tetrasodium HEDP); and / or The weight average molecular weight of the ethylene glycol oligomer is 200-600; and / or The ethylene glycol oligomer is polyethylene glycol; and / or The content of the chelating agent in every 100 ml of the impregnation solution is 0.01 to 5 g, preferably 0.5 to 2 g; and / or In every 100 ml of the impregnation solution, the content of ethylene glycol oligomer and citric acid is 0.2 to 5 g respectively; and / or The impregnation contact is an equal volume impregnation contact.

8. The preparation method according to any one of claims 3 to 7, wherein: The preparation method of the composite carrier comprises: (1) mixing a binder source, ZSM-5 powder, β-zeolite powder and an additive to obtain a mixture I; (2) adding the mixture I to an acidic aqueous solution, kneading, forming, drying and calcining; Preferably, The acidic substance concentration in the acidic aqueous solution is 1 wt% to 6 wt%; and / or The weight ratio of mixture I to the acidic aqueous solution is 100:5 to 100:75, preferably 100:50 to 100:70; and / or In step (2), the calcination conditions include: a temperature of 450 to 650° C. and a time of 0.5 to 24 h; Preferably, The ZSM-5 powder is hydrogen-type, and the SiO2 / Al2O3 molar ratio is 20 to 200; and / or The beta zeolite powder is in the hydrogen form, and the SiO2 / Al2O3 molar ratio is 20 to 200; and / or The binder source is selected from at least one of silica sol, water glass, pseudo-boehmite, white carbon black, and alumina sol; and / or The auxiliary agent is selected from at least one of methyl cellulose, field blue powder, polyethylene glycol, calcium nitrate, potassium nitrate and hydroxymethyl cellulose; The acidic substance in the acidic aqueous solution is selected from at least one of nitric acid, phosphoric acid, acetic acid, citric acid and tartaric acid.

9. The hydrocracking catalyst according to claim 1 or 2 is used in refining aromatic-rich fraction oil, cracking C9 + , ethylene tar, coal tar, catalytic light diesel or reforming C9 + Application in hydrocracking.

10. A method for preparing BTX by hydrocracking of aromatic-rich distillate oil, characterized in that: The method includes: In the presence of a catalyst, under hydrocracking reaction conditions, the refined aromatic-rich light cracking fraction oil is hydrocracking, wherein the catalyst comprises the hydrocracking catalyst according to claim 1 or 2; Preferably, The refined aromatic-rich light cracking distillate oil includes: an initial distillation point of 85-170°C, a final distillation point of 220-280°C, a sulfur content of <50ug / mL, a nitrogen content of <10ug / mL; a monocyclic aromatic hydrocarbon content of >90wt%; Hydrocracking reaction conditions include: reactor inlet temperature 300-500°C, fresh feed space velocity 0.6-4.0h -1 , hydrogen-oil volume ratio 500-2000, pressure 2-8MPa; After 2000 hours online, the BTX yield in the liquid product was greater than 55%, wherein the toluene content was greater than 50%.

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