A hydrogenation catalyst for a polycyclic aromatic hydrocarbon-rich feedstock, and a preparation method and application thereof

Abstract

The present disclosure relates to a hydrogenation catalyst for feedstock rich in polycyclic aromatic hydrocarbons, and a preparation method and application thereof. The hydrogenation catalyst comprises a carrier and an active metal component supported on the carrier; the active metal component comprises a Group VIII metal element and a Group VIB metal element; the carrier comprises a composite molecular sieve and a heat-resistant inorganic oxide matrix, the composite molecular sieve comprises a first molecular sieve and a second molecular sieve, the first molecular sieve is a Y molecular sieve, and the second molecular sieve is a molecular sieve with an N value greater than 0.6 and an I value greater than 1. The catalyst of the present disclosure can realize directional hydrogenation ring opening of polycyclic aromatic hydrocarbons in a diesel fraction, thereby improving the cetane number of diesel products, while reducing the density and polycyclic aromatic hydrocarbon content.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of catalysts, in particular, to a hydrogenation catalyst for feedstock rich in polycyclic aromatic hydrocarbons and a preparation method and application thereof. BACKGROUND

[0002] In recent years, the quality standards of fuel oil are becoming more and more stringent, and the accommodation capacity of fuel oil market for polycyclic aromatic hydrocarbon materials is gradually declining. Therefore, the efficient utilization of polycyclic aromatic hydrocarbon materials rich in polycyclic aromatic hydrocarbons has become one of the major challenges faced by oil refining enterprises. A large number of basic research results show that polycyclic aromatic hydrocarbons can be saturated by hydrogenation, ring-opening, cracking and other reactions, and then converted into high-value chemical products such as low-carbon aromatic hydrocarbons and / or low-carbon olefins, alkanes and the like, helping oil refining enterprises to transform from oil refining to chemical industry and improve quality and efficiency.

[0003] Polycyclic aromatic hydrocarbons are mostly converted into light aromatic hydrocarbons by using a hydrocracking process or a combination process of hydroprocessing and catalytic cracking. Whether it is hydrocracking or a combination process, the polycyclic aromatic hydrocarbon material needs to be subjected to advanced hydrogenation pretreatment or hydrofining, and the polycyclic aromatic hydrocarbons are converted into partially saturated monocyclic aromatic hydrocarbons by hydrogenation reaction, and then ring-opening cracking reaction occurs in the hydrogenation cracking reaction section or the catalytic cracking unit to obtain light aromatic hydrocarbons. A large number of studies have found that the saturation depth and product structure of polycyclic aromatic hydrocarbons in the hydrogenation pretreatment or hydrofining unit (collectively referred to as hydroprocessing) will affect the hydrogen consumption of the overall process, and are key factors affecting the reaction activity and product distribution of subsequent hydrocracking or catalytic cracking. Therefore, fine control of the depth and molecular structure of the hydrogenation product of polycyclic aromatic hydrocarbons in the hydroprocessing unit is the core of producing light aromatic hydrocarbons from polycyclic aromatic hydrocarbons.

[0004] Chinese patent 201310145548.0 discloses a catalyst for the hydrogenation ring-opening reaction of condensed aromatic hydrocarbons. The catalyst uses modified high-silicon-aluminum ratio H-Beta molecular sieve and inorganic oxide as the carrier, and noble metal Pt, Pd or Ir as the active component. The catalyst has the characteristics of inhibiting deep cracking, promoting selective ring-opening of aromatic hydrocarbons and product isomerization.

[0005] Chinese patent 201110350797.4 discloses a catalyst carrier for diesel hydro-upgrading, which comprises modified Beta molecular sieve and alumina. The modified Beta molecular sieve is directly subjected to ammonium exchange and template removal treatment after crystallization, and then subjected to hydrothermal treatment and aluminum salt solution treatment, so that the Beta molecular sieve has high silicon-aluminum ratio, large specific surface area, suitable acid distribution and acid distribution, reasonable pore structure, and high isomerization performance and conversion capacity for aromatic hydrocarbons in catalytic diesel.

[0006] Chinese patent 201610920285.X discloses a mesopore-rich Y molecular sieve, the proportion of mesopore volume in the total pore volume of the molecular sieve is 20-65%, in the 27Al MAS NMR spectrum of the molecular sieve, the ratio of the peak area of the chemical shift of 60ppm±2ppm resonance signal to the peak area of the chemical shift of 55ppm±2ppm resonance signal is (1.5-5):1, and the proportion of the peak area of the chemical shift of 0ppm±2ppm resonance signal in the total peak area is not more than 5%.

[0007] The catalyst provided by the above patent document can promote the selective ring-opening of aromatic hydrocarbons to some extent, but the removal rate of polycyclic aromatic hydrocarbons in diesel products is still not ideal. SUMMARY

[0008] The purpose of the present disclosure is to provide a diesel hydro-upgrading catalyst to achieve directional hydrogenation ring-opening of polycyclic aromatic hydrocarbons in diesel fractions.

[0009] To achieve the above-mentioned purpose, the first aspect of the present disclosure provides a hydrogenation catalyst for raw materials rich in polycyclic aromatic hydrocarbons, the hydrogenation catalyst comprising a carrier and an active metal component loaded on the carrier; the active metal component comprises a Group VIII metal element and a Group VIB metal element; the carrier comprises a composite molecular sieve and a heat-resistant inorganic oxide matrix, the composite molecular sieve comprises a first molecular sieve and a second molecular sieve, the first molecular sieve is a Y molecular sieve, and the second molecular sieve is a molecular sieve with an N value greater than 0.6 and an I value greater than 1; wherein the N value of a certain molecular sieve to be tested is defined as the ratio of the adsorption amount of the molecular sieve to be tested to double-ring aromatic hydrocarbons and their derivatives to the adsorption amount of a standard molecular sieve to double-ring aromatic hydrocarbons and their derivatives, the standard molecular sieve is a HY molecular sieve, the molar ratio of SiO2 and Al2O of the standard molecular sieve is 5.4, and the cell constant is 24.60 angstroms; the I value of a certain molecular sieve to be tested is defined as the ratio of the square of the adsorption amount of the molecular sieve to be tested to methylindane to the product of the adsorption amount of the molecular sieve to be tested to tetrahydronaphthalene and the adsorption amount of the molecular sieve to be tested to butylbenzene.

[0010] Optionally, the I value of the second molecular sieve is 1.2-10, and the N value is 0.6-10; preferably, the I value of the second molecular sieve is 1.2-6, and the N value is 0.6-4; optionally, the pore volume of the second molecular sieve is 0.4-0.8cm 3 / g, and the acid density is 0.8-2.5μmol / m 2 .

[0011] Optionally, the weight ratio of the first molecular sieve to the second molecular sieve in the composite molecular sieve is 1:9-9:1, preferably 1:1-9:1.

[0012] Optionally, the content of the composite molecular sieve is 5-50% by weight, and the content of the heat-resistant inorganic oxide matrix is 50-95% by weight, based on the total weight of the carrier.

[0013] Optionally, the catalyst contains 40-75% by weight of the carrier, 1.5-6% by weight of the Group VIII metal element, and 10-35% by weight of the Group VIB metal element, based on the total weight of the catalyst.

[0014] Optionally, the first molecular sieve is selected from at least one of HY molecular sieve, rare earth Y molecular sieve REY, rare earth HY molecular sieve REHY, ultrastable Y molecular sieve USY, partially amorphous USY, rare earth ultrastable Y molecular sieve REUSY, titanium-containing Y molecular sieve, phosphorus-containing Y and ultrastable and HY type molecular sieve, and dealuminized Y type molecular sieve; preferably, the first molecular sieve is selected from at least one of HY molecular sieve, rare earth Y molecular sieve, rare earth HY molecular sieve, ultrastable Y molecular sieve, rare earth ultrastable Y molecular sieve, partially amorphous Y molecular sieve, titanium-containing Y molecular sieve, and phosphorus-containing Y type molecular sieve; the second molecular sieve is selected from at least one of OSB-1 molecular sieve, Linde Type A molecular sieve, SSZ-35 molecular sieve, ITQ-52 molecular sieve, SSZ-59 molecular sieve, SSZ-53 molecular sieve, SSZ-23 molecular sieve, SSZ-44 molecular sieve, SSZ-52 molecular sieve, CIT-1 molecular sieve, and AlPO-52 molecular sieve; and the heat-resistant inorganic oxide matrix is selected from at least one of alumina, silica, and silica-alumina.

[0015] The second aspect of the present disclosure provides a method for preparing a hydrogenation catalyst, which comprises:

[0016] S1, mixing the first molecular sieve, the second molecular sieve, the heat-resistant inorganic oxide matrix, and the auxiliary agent, then kneading and extruding to obtain an extruded strip; performing first drying and first calcination on the extruded strip to obtain a carrier; the auxiliary agent is selected from at least one of inorganic binder and extrusion aid;

[0017] S2, impregnating the carrier with an aqueous solution containing a Group VIII metal-containing compound and a Group VIB metal-containing compound to obtain an impregnated carrier; performing second drying and activation treatment on the impregnated carrier.

[0018] Optionally, the weight ratio of the first molecular sieve, the second molecular sieve, and the heat-resistant inorganic oxide matrix is 0.5-45:0.5-45:5-95.

[0019] Optionally, in step S1, the conditions for the first drying treatment include: a drying temperature of 80-300℃, preferably 100-200℃; and a drying time of 1-12 hours, preferably 2-8 hours; the conditions for the first calcination include: a calcination temperature of 350-850℃, preferably 450-650℃; and a calcination time of 1-12 hours, preferably 2-6 hours; in step S2, the conditions for the impregnation include: an impregnation temperature of room temperature -150℃; and an impregnation time of 1-6 hours; the conditions for the second drying include: a temperature of 100-300℃, preferably 100-150℃; and a time of 2-8 hours; and the conditions for the activation treatment include: a temperature of 100-350℃, preferably 120-250℃; and a time of 1-12 hours, preferably 2-6 hours.

[0020] A third aspect of this disclosure provides a method for hydrocracking a feedstock oil rich in polycyclic aromatic hydrocarbons, wherein the feedstock oil and hydrogen are contacted with the aforementioned hydrocracking catalyst and subjected to a hydrocracking reaction, wherein the hydrocracking reaction is carried out using a fixed-bed single-stage series and diesel cycle process.

[0021] Through the above technical solution, the catalyst disclosed herein can achieve directional hydrogenation and ring-opening of polycyclic aromatic hydrocarbons in diesel fractions, thereby increasing the cetane number of diesel products while reducing density and polycyclic aromatic hydrocarbon content.

[0022] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Detailed Implementation

[0023] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this disclosure.

[0024] The first aspect of this disclosure provides a hydrogenation catalyst for a feedstock rich in polycyclic aromatic hydrocarbons (PAHs). The hydrogenation catalyst includes a support and an active metal component supported on the support. The active metal component includes Group VIII and Group VIB metal elements. The support comprises a composite molecular sieve and a heat-resistant inorganic oxide matrix. The composite molecular sieve includes a first molecular sieve and a second molecular sieve. The first molecular sieve is a Y molecular sieve, and the second molecular sieve is a molecular sieve with an N value greater than 0.6 and an I value greater than 1. The N value of a given molecular sieve is defined as the ratio of the adsorption amount of the given molecular sieve for bicyclic aromatic hydrocarbons and their derivatives to the adsorption amount of a standard molecular sieve for bicyclic aromatic hydrocarbons and their derivatives. The standard molecular sieve is a HY molecular sieve with a SiO2 to Al2O molar ratio of 5.4 and a cell constant of 24.60 Å. The I value of a given molecular sieve is defined as the ratio of the square of the adsorption amount of the given molecular sieve for methyl indene to the product of the adsorption amount of the given molecular sieve for tetrahydronaphthalene and the adsorption amount of the given molecular sieve for butylbenzene.

[0025] The N and I values ​​described in this disclosure are obtained through an adsorption molar ratio test method. The specific method for testing the N value is as follows: First, accurately measure 100 mL of tetrahydronaphthalene solution (at room temperature), then add a measured amount of molecular sieve material (5 g). Under inert gas (N2) protection, at 1 atm, and constant temperature and humidity at 360°C, stir for 10 hours. Then filter, re-adjust the filtrate to the correct volume, cool to room temperature, and measure the solution volume again using a graduated cylinder to obtain the adsorption volume difference ΔV of the tested molecular sieve. The formula for calculating N is:

[0026] N=(ΔV 测试分子筛 *M 测试分子筛 ) / (ΔV Y型分子筛 *M Y型分子筛 )

[0027] Where ΔV 测试分子筛 ΔV Y型分子筛 M represents the volume difference in adsorption of tetrahydronaphthalene between the test molecular sieve and the standard molecular sieve. 测试分子筛 M Y型分子筛 These represent the molar masses of the test molecular sieve and the standard molecular sieve, respectively.

[0028] The specific method for testing the I value is as follows: First, accurately measure 100 ml of tetrahydronaphthalene solution, methylindene, and butylbenzene (at room temperature), then add a measured amount of molecular sieve material (5 g). Under inert gas (N2) protection, at 1 atm, and constant temperature and stirring at 360°C for 10 hours, the mixture is then filtered. The filtrate is re-diluted to the required volume and cooled to room temperature. The volume of the solution is then measured again using a graduated cylinder to obtain the adsorption volume difference ΔV. 测试分子筛_甲基茚满 ΔV 测试分子筛_四氢萘 ΔV 测试分子筛_丁基苯 The formula for calculating the I value is:

[0029] I = ΔV 测试分子筛_甲基茚满 2 / (ΔV 测试分子筛_丁基苯 *ΔV 测试分子筛_四氢萘 )

[0030] Where, ΔV 测试分子筛_甲基茚满 ΔV 测试分子筛_苯 Greater than 0.

[0031] This disclosure achieves rational screening of the acidic component molecular sieve of the catalyst through N value and I value, enhances the matching degree between the molecular sieve pore structure and the reactants, reaction intermediates and product molecules in the polycyclic aromatic hydrocarbon (PAH) hydrogenation process, realizes effective control of the saturation depth and molecular structure of hydrogenation products in the PAH hydrogenation process, provides ideal feedstock for the hydrocracking reaction section or catalytic cracking unit with lower hydrogen consumption, and improves the efficiency and economy of PAH to light aromatic hydrocarbon production technology.

[0032] In a preferred embodiment of this disclosure, the I value of the second molecular sieve is 1.2-10, and the N value is 0.6-10; preferably, the I value of the second molecular sieve is 1.2-6, and the N value is 0.6-4; optionally, the pore volume of the second molecular sieve can be 0.4-0.8 cm³. 3 / g, acid density can be 0.8-2.5μmol / m 2 .

[0033] According to this disclosure, the weight ratio of the first molecular sieve to the second molecular sieve in the composite molecular sieve can be 1:9-9:1, preferably 1:1-9:1.

[0034] According to this disclosure, based on the total weight of the carrier, the content of the composite molecular sieve can be 5-50% by weight, and the content of the heat-resistant inorganic oxide matrix can be 50-95% by weight.

[0035] According to this disclosure, based on the total weight of the catalyst and calculated as oxides, the catalyst may contain 40-75% by weight of support, 1.5-6% by weight of Group VIII metals, and 10-35% by weight of Group VIB metals.

[0036] According to this disclosure, the first molecular sieve may be selected from at least one of HY molecular sieve, rare earth type Y molecular sieve REY, rare earth type HY molecular sieve REHY, ultrastable Y molecular sieve USY, partially amorphous USY, rare earth type ultrastable Y molecular sieve REUSY, titanium-containing Y molecular sieve, phosphorus-containing Y and ultrastable HY type molecular sieves and dealuminated Y type molecular sieves; preferably, the first molecular sieve may be selected from at least one of HY molecular sieve, rare earth Y molecular sieve, rare earth HY molecular sieve, ultrastable Y molecular sieve, rare earth ultrastable Y molecular sieve, partially amorphous Y molecular sieve, titanium-containing Y molecular sieve and phosphorus-containing Y type molecular sieves; the second molecular sieve may be selected from at least one of OSB-1 molecular sieve, Linde Type A molecular sieve, SSZ-35 molecular sieve, ITQ-52 molecular sieve, SSZ-59 molecular sieve, SSZ-53 molecular sieve, SSZ-23 molecular sieve, SSZ-44 molecular sieve, SSZ-52 molecular sieve, CIT-1 molecular sieve and AlPO-52 molecular sieve.

[0037] The heat-resistant inorganic oxide matrix described in this disclosure can be selected from at least one of alumina, silicon oxide, and silicon-alumina. The alumina is selected from one or more transition phases of γ, η, θ, δ, and χ, or may contain one or more transition phases of γ, η, θ, δ, and χ selected from silicon, titanium, magnesium, boron, zirconium, thorium, niobium, and rare earth additives. Preferably, it is γ-alumina and γ-alumina containing one or more additives selected from silicon, phosphorus, titanium, magnesium, boron, zirconium, thorium, niobium, and rare earth additives. These can be commercially available or obtained using any existing method. Silicon-alumina preferably has a pseudo-boehmite structure and can also be commercially available or prepared using any existing technology. For example, the Siral series of commercially available silicon-alumina products manufactured by Condea GmbH in Germany have a pseudo-boehmite structure and can be used in this disclosure.

[0038] The catalyst provided in this disclosure can be used in any reactor capable of contacting the feedstock with the catalyst under hydrotreating conditions, for example, in a fixed-bed reactor, a moving-bed reactor, or a fluidized-bed reactor. Other types of hydrocarbon feedstocks can also be directly processed for hydrotreating. The hydrocarbon feedstock can also be various heavy mineral oils or synthetic oils or their mixed distillate fractions, such as those selected from crude oil, distillate oils, solvent-refined oils, wax pastes, under-wax oils, Fischer-Tropsch synthetic oils, coal liquefaction oils, light deasphalted oils, and heavy deasphalted oils, or one or more of these. It is particularly suitable for hydrotreating or hydrocracking processes of diesel fuel, especially low-grade diesel fuel rich in polycyclic aromatic hydrocarbons.

[0039] A second aspect of this disclosure provides a method for preparing a hydrogenation catalyst, the method comprising:

[0040] S1. The first molecular sieve, the second molecular sieve, the heat-resistant inorganic oxide matrix and the additives are mixed, kneaded and extruded to obtain an extruded strip; the extruded strip is subjected to a first drying and a first calcination to obtain a carrier; the additives are selected from at least one of inorganic binders and extrusion aids;

[0041] S2. The carrier is impregnated with an aqueous solution of a compound containing a Group VIII metal and a Group VIB metal to obtain an impregnated carrier; the impregnated carrier is then subjected to a second drying and activation treatment.

[0042] According to this disclosure, the weight ratio of the first molecular sieve, the second molecular sieve, and the heat-resistant inorganic oxide matrix can be 0.5-45:0.5-45:5-95.

[0043] According to this disclosure, in step S1, the conditions for the first drying treatment may include: a drying temperature of 80-300℃, preferably 100-200℃; and a drying time of 1-12 hours, preferably 2-8 hours; the conditions for the first calcination may include: a calcination temperature of 350-850℃, preferably 450-650℃; and a calcination time of 1-12 hours, preferably 2-6 hours; in step S2, the conditions for the impregnation may include: an impregnation temperature of room temperature -150℃; and an impregnation time of 1-6 hours; the conditions for the second drying may include: a temperature of 100-300℃, preferably 100-150℃; and a time of 2-8 hours; the conditions for the activation treatment may include: a temperature of 100-350℃, preferably 120-250℃; and a time of 1-12 hours, preferably 2-6 hours.

[0044] A third aspect of this disclosure provides a method for hydrocracking a feedstock oil rich in polycyclic aromatic hydrocarbons, wherein the feedstock oil and hydrogen are contacted with the aforementioned hydrocracking catalyst and subjected to a hydrocracking reaction, wherein the hydrocracking reaction is carried out using a fixed-bed single-stage series and diesel cycle process.

[0045] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.

[0046] Example 1

[0047] 200.0 g of pseudoboehmite (Changling Branch of Catalyst) with a dry basis of 70%, 42.4 g of Y-type molecular sieve with a dry basis of 85%, and 28.9 g of SSZ-44 molecular sieve with a dry basis of 83% were weighed out, and appropriate amounts of additives, including inorganic binders and extrusion aids, were added and mixed evenly. The mixture was then extruded into a butterfly-shaped carrier strip with an outer circle diameter of 1.6 mm on an extruder, dried at 120℃ for 3 hours, and calcined at 600℃ for 4 hours to obtain carrier Z1.

[0048] 100 g of support Z1 was impregnated for 3 hours in 83 mL of a mixed solution of ammonium metatungstate, basic nickel carbonate, and phosphoric acid containing 265.1 g / L WO3, 24.1 g / L NiO, and 12.0 g / L P2O5, respectively. After drying at 120 °C for 2 hours, it was calcined at 450 °C for 3 hours to obtain catalyst C1. The composition based on the catalyst is shown in Table 2.

[0049] Example 2

[0050] 200.0 g of pseudoboehmite (Changling Branch of Catalyst) with a dry basis of 70%, 28.2 g of Y-type molecular sieve with a dry basis of 85%, and 43.4 g of SSZ-44 molecular sieve with a dry basis of 83% were weighed out, and appropriate amounts of additives, including inorganic binders and extrusion aids, were added and mixed evenly. The mixture was then extruded into a butterfly-shaped carrier strip with an outer circle diameter of 1.6 mm on an extruder, dried at 120℃ for 3 hours, and calcined at 600℃ for 4 hours to obtain carrier Z2.

[0051] 100 g of support Z2 was impregnated for 3 hours in 83 mL of a mixed solution of ammonium metatungstate, basic nickel carbonate, and phosphoric acid containing 265.1 g / L WO3, 24.1 g / L NiO, and 12.0 g / L P2O5, respectively. After drying at 120 °C for 2 hours, it was calcined at 450 °C for 3 hours to obtain catalyst C2. The theoretical composition after calcination, based on the catalyst, is shown in Table 2.

[0052] Example 3

[0053] 200.0 g of pseudoboehmite (Catalyst Changling Branch) with a dry basis of 70%, 28.2 g of Y-type molecular sieve with a dry basis of 85%, and 43.4 g of SSZ-44 molecular sieve with a dry basis of 83% were weighed out, and appropriate amounts of additives, including organic binders and extrusion aids, were added and mixed evenly. The mixture was then extruded into a butterfly-shaped carrier strip with an outer circumcircle diameter of 1.6 mm on an extruder, dried at 120℃ for 3 hours, and calcined at 600℃ for 4 hours to obtain carrier Z3.

[0054] 100 g of support Z3 was impregnated for 3 hours in 99 mL of a mixed solution of ammonium metatungstate, basic nickel carbonate, and phosphoric acid containing 222.2 g / L WO3, 20.2 g / L NiO, and 10.1 g / L P2O5, respectively. After drying at 120 °C for 2 hours, it was calcined at 450 °C for 3 hours to obtain catalyst C3. The theoretical composition after calcination, based on the catalyst, is shown in Table 2.

[0055] Example 4

[0056] 100 g of support Z2 was impregnated for 3 hours in 83 mL of a mixed solution of ammonium metatungstate, basic nickel carbonate, and phosphoric acid containing 90.4 g / L WO3, 12.0 g / L NiO, and 6.0 g / L P2O5, respectively. After drying at 120 °C for 2 hours, it was calcined at 450 °C for 3 hours to obtain catalyst C4. The theoretical composition after calcination, based on the catalyst, is shown in Table 2.

[0057] Example 5

[0058] 100 g of support Z2 was impregnated for 3 hours in 83 mL of a mixed solution of ammonium metatungstate, basic nickel carbonate, and phosphoric acid containing WO3 530.1 g / L, NiO 108.4 g / L, and P2O5 24.1 g / L, respectively. After drying at 120 °C for 2 hours, it was calcined at 450 °C for 3 hours to obtain catalyst C5. The theoretical composition after calcination, based on the catalyst, is shown in Table 2.

[0059] Example 6

[0060] 100 g of support Z2 was impregnated for 3 hours in 83 mL of a mixed solution containing molybdenum trioxide, basic nickel carbonate, and phosphoric acid, with molybdenum O3 at 180.7 g / L, NiO at 24.1 g / L, and P2O5 at 12.0 g / L respectively. After drying at 120 °C for 2 hours, it was calcined at 450 °C for 3 hours to obtain catalyst C6. The theoretical composition after calcination, based on the catalyst, is shown in Table 2.

[0061] Example 7

[0062] Weigh 200.0 g of pseudoboehmite (Changling Branch of Catalyst) with a dry basis of 70%, 28.2 g of Y-type molecular sieve with a dry basis of 85%, and 45.0 g of ITQ-52 molecular sieve with a dry basis of 80%. Add appropriate amounts of additives, including inorganic binders and extrusion aids, and mix evenly. Extrude the mixture into a butterfly-shaped carrier strip with an outer circle diameter of 1.6 mm on an extruder. Dry the strip at 120℃ for 3 hours and calcine it at 600℃ for 4 hours to obtain carrier Z7.

[0063] 100 g of support Z7 was impregnated for 3 hours in 81 mL of a mixed solution of ammonium metatungstate, basic nickel carbonate, and phosphoric acid containing 271.6 g / L WO3, 24.7 g / L NiO, and 12.3 g / L P2O5, respectively. After drying at 120 °C for 2 hours, it was calcined at 450 °C for 3 hours to obtain catalyst C7. The theoretical composition after calcination, based on the catalyst, is shown in Table 2.

[0064] Example 8

[0065] Weigh 114.3 g of pseudoboehmite (Changling Branch of Catalyst) with a dry basis of 70%, 28.2 g of Y-type molecular sieve with a dry basis of 85%, 45.0 g of ITQ-52 molecular sieve with a dry basis of 80%, and 78.9 g of amorphous silica-alumina material (Siral40 from Condea, Germany) with a dry basis of 76%. Add appropriate amounts of additives, including inorganic binders and extrusion aids, and mix evenly. Extrude the mixture into a butterfly-shaped carrier strip with an outer circle diameter of 1.6 mm on an extruder. Dry the strip at 120°C for 3 hours and calcine it at 600°C for 4 hours to obtain carrier Z8.

[0066] 100 g of support Z8 was impregnated for 3 hours in 81 mL of a mixed solution of ammonium metatungstate, basic nickel carbonate, and phosphoric acid containing 271.6 g / L WO3, 24.7 g / L NiO, and 12.3 g / L P2O5, respectively. After drying at 120 °C for 2 hours, it was calcined at 450 °C for 3 hours to obtain catalyst C8. The theoretical composition after calcination, based on the catalyst, is shown in Table 2.

[0067] Example 9

[0068] 257.1 g of pseudoboehmite (Changling Branch of Catalyst) with a dry basis of 70%, 9.4 g of Y-type molecular sieve with a dry basis of 85%, and 15.0 g of ITQ-52 molecular sieve with a dry basis of 80% were weighed out, and appropriate amounts of additives, including inorganic binders and extrusion aids, were added and mixed evenly. The mixture was then extruded into a butterfly-shaped carrier strip with an outer circumcircle diameter of 1.6 mm on an extruder, dried at 120℃ for 3 hours, and calcined at 600℃ for 4 hours to obtain carrier Z9.

[0069] 100 g of support Z9 was impregnated for 3 hours in 80 mL of a mixed solution of ammonium metatungstate, basic nickel carbonate, and phosphoric acid containing 275.0 g / L WO3, 25.0 g / L NiO, and 12.5 g / L P2O5, respectively. After drying at 120 °C for 2 hours, it was calcined at 450 °C for 3 hours to obtain catalyst C9. The theoretical composition after calcination, based on the catalyst, is shown in Table 2.

[0070] Example 10

[0071] Weigh 142.9 g of pseudoboehmite (Catalyst Changling Branch) with a dry basis of 70%, 47.1 g of Y-type molecular sieve with a dry basis of 85%, and 75.0 g of ITQ-52 molecular sieve with a dry basis of 80%. Add appropriate amounts of additives, including inorganic binders and extrusion aids, and mix evenly. Extrude the mixture into a butterfly-shaped carrier strip with an outer circumcircle diameter of 1.6 mm on an extruder. Dry the strip at 120℃ for 3 hours and calcine it at 600℃ for 4 hours to obtain carrier Z10.

[0072] 100 g of support Z10 was impregnated for 3 hours in 85 mL of a mixed solution of ammonium metatungstate, basic nickel carbonate, and phosphoric acid containing 258.8 g / L WO3, 23.5 g / L NiO, and 11.8 g / L P2O5, respectively. After drying at 120 °C for 2 hours, it was calcined at 450 °C for 3 hours to obtain catalyst C10. The theoretical composition after calcination, based on the catalyst, is shown in Table 2.

[0073] Comparative Example 1

[0074] Weigh 200.0 g of pseudoboehmite (Changling Branch of Catalyst) with a dry basis of 70% and 70.6 g of Y-type molecular sieve with a dry basis of 85%, and add appropriate amounts of additives including inorganic binders and extrusion aids, mix evenly, and extrude into butterfly-shaped carrier strips with an outer circle diameter of 1.6 mm on an extruder. Dry at 120℃ for 3 hours and calcine at 600℃ for 4 hours to obtain carrier DZ.

[0075] 100 g of support DZ was impregnated for 3 hours in 78 mL of a mixed solution of ammonium metatungstate, basic nickel carbonate, and phosphoric acid containing 282.1 g / L WO3, 25.6 g / L NiO, and 12.8 g / L P2O5, respectively. After drying at 120 °C for 2 hours, it was calcined at 450 °C for 3 hours to obtain catalyst DC. The theoretical composition after calcination, based on the catalyst, is shown in Table 2.

[0076] Table 1

[0077] Molecular sieve number Pore volume / (cm 3 / g) Acid density / (mmol / m 2 )] N value I value SSZ-44 0.578 1.430 0.74 3.75 ITQ-52 0.501 1.478 0.75 2.01 Y 0.412 3.121 1.00 1.18

[0078] Table 2

[0079]

[0080]

[0081] Test case

[0082] With a density of 0.9561 g / cm³ 3 Using catalytic cracking diesel fuel with a sulfur content of 9800 ppm, a nitrogen content of 743 ppm, and a total aromatic hydrocarbon content of 85.7% as feedstock, the performance of the catalysts C1, C2, C3, C7, and DC provided in this disclosure was evaluated in a 30 mL fixed-bed unit. The specific method was as follows: the upper part of the bed was loaded with industrial refined catalyst, and the lower part was loaded with catalyst, with the C1 catalyst being loaded at a rate of 15 mL. The catalyst was pre-sulfurized before the feedstock oil was introduced under the following conditions: sulfurization at 110°C for 2 hours and sulfurization at 300°C for 4 hours. The sulfided oil was kerosene containing 6% carbon disulfide by weight. The reaction conditions in the hydrorefining reaction zone were: reaction temperature 350°C, hydrogen partial pressure 6.5 MPa, and liquid hourly space velocity 1.5 h⁻¹. -1The hydrogen-to-oil volume ratio was 800. Reaction conditions in the hydrotreating reaction zone were: reaction temperature 370℃, hydrogen partial pressure 6.5 MPa, and liquid hourly space velocity (LHSV) of the modifier 1.2 h⁻¹. -1 The hydrogen-to-oil volume ratio was 800. The test results are listed in Table 3.

[0083] Table 3

[0084]

[0085] The test results in Table 3 show that, compared with existing catalysts, the catalyst disclosed in this paper has higher hydrodearomatization performance, and the proportion of six-membered ring isomers such as indane in diesel products in monocyclic aromatic hydrocarbons is increased, which is more conducive to subsequent hydrocracking or catalytic cracking to produce high-value products through ring-opening cracking reactions.

[0086] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0087] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0088] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A hydrogenation catalyst for feedstocks rich in polycyclic aromatic hydrocarbons, characterized in that, The hydrogenation catalyst comprises a support and an active metal component supported on the support; the active metal component comprises Group VIII and Group VIB metal elements; the support comprises a composite molecular sieve and a heat-resistant inorganic oxide matrix, the composite molecular sieve comprising a first molecular sieve and a second molecular sieve, the first molecular sieve being a Y molecular sieve, and the second molecular sieve being a molecular sieve with an N value greater than 0.6 and an I value greater than 1; the pore volume of the second molecular sieve is 0.4-0.8 cm³. 3 / g, acid density is 0.8-2.5μmol / m 2 ; The second molecular sieve is selected from at least one of OSB-1 molecular sieve, Linde Type A molecular sieve, SSZ-35 molecular sieve, ITQ-52 molecular sieve, SSZ-59 molecular sieve, SSZ-53 molecular sieve, SSZ-23 molecular sieve, SSZ-44 molecular sieve, SSZ-52 molecular sieve, CIT-1 molecular sieve, and AlPO-52 molecular sieve. Based on the total weight of the catalyst, and calculated as oxides, the catalyst contains 40-75% by weight of support, 1.5-6% by weight of Group VIII metal elements, and 10-35% by weight of Group VIB metal elements; wherein, the N value of a certain molecular sieve to be tested is defined as the ratio of the adsorption amount of the molecular sieve to bicyclic aromatic hydrocarbons and their derivatives to the adsorption amount of a standard molecular sieve to bicyclic aromatic hydrocarbons and their derivatives, wherein the standard molecular sieve is a HY molecular sieve, the molar ratio of SiO2 to Al2O3 of the standard molecular sieve is 5.4, and the cell constant is 24.60 Å; the I value of a certain molecular sieve to be tested is defined as the ratio of the square of the adsorption amount of the molecular sieve to methyl indene to the product of the adsorption amount of the molecular sieve to tetrahydronaphthalene and the adsorption amount of the molecular sieve to butylbenzene.

2. The hydrogenation catalyst according to claim 1, wherein, The second molecular sieve has an I value of 1.2-10 and an N value of 0.6-10.

3. The hydrogenation catalyst according to claim 2, wherein, The second molecular sieve has an I value of 1.2-6 and an N value of 0.6-4.

4. The hydrogenation catalyst according to claim 1, wherein, The weight ratio of the first molecular sieve to the second molecular sieve in the composite molecular sieve is 1:9-9:

1.

5. The hydrogenation catalyst according to claim 4, wherein, The weight ratio of the first molecular sieve to the second molecular sieve in the composite molecular sieve is 1:1 to 9:

1.

6. The hydrogenation catalyst according to claim 1, wherein, Based on the total weight of the carrier, the content of the composite molecular sieve is 5-50% by weight, and the content of the heat-resistant inorganic oxide matrix is ​​50-95% by weight.

7. The hydrogenation catalyst according to claim 1, wherein, The first molecular sieve is selected from at least one of the following: HY molecular sieve, rare earth Y molecular sieve REY, rare earth HY molecular sieve REHY, ultrastable Y molecular sieve USY, partially amorphous USY, rare earth ultrastable Y molecular sieve REUSY, titanium-containing Y molecular sieve, phosphorus-containing Y and ultrastable and HY molecular sieves and dealuminized Y molecular sieve. The heat-resistant inorganic oxide matrix is ​​selected from at least one of alumina, silicon oxide, and silicon-alumina.

8. The hydrogenation catalyst according to claim 7, wherein, The first molecular sieve is selected from at least one of HY molecular sieve, rare earth Y molecular sieve, rare earth HY molecular sieve, ultrastable Y molecular sieve, rare earth ultrastable Y molecular sieve, partially amorphous Y molecular sieve, titanium-containing Y molecular sieve and phosphorus-containing Y-type molecular sieve.

9. A method for preparing the hydrogenation catalyst according to any one of claims 1-8, characterized in that, The method includes: S1. The first molecular sieve, the second molecular sieve, the heat-resistant inorganic oxide matrix and the additives are mixed, kneaded and extruded to obtain an extruded strip; the extruded strip is subjected to a first drying and a first calcination to obtain a carrier; the additives are selected from at least one of inorganic binders and extrusion aids; S2. The carrier is impregnated with an aqueous solution of a compound containing a Group VIII metal and a Group VIB metal to obtain an impregnated carrier; the impregnated carrier is then subjected to a second drying and activation treatment.

10. The method according to claim 9, wherein, The weight ratio of the first molecular sieve, the second molecular sieve, and the heat-resistant inorganic oxide matrix is ​​0.5-45:0.5-45:5-95.

11. The method according to claim 9, wherein, In step S1, the conditions for the first drying treatment include: a drying temperature of 80-300℃ and a drying time of 1-12 hours; the conditions for the first calcination include: a calcination temperature of 350-850℃ and a calcination time of 1-12 hours. In step S2, the conditions for impregnation include: an impregnation temperature of room temperature to 150°C and an impregnation time of 1 to 6 hours; the conditions for the second drying include: a temperature of 100 to 300°C and a time of 2 to 8 hours; and the conditions for the activation treatment include: a temperature of 100 to 350°C and a time of 1 to 12 hours.

12. The method according to claim 11, wherein, In step S1, the conditions for the first drying treatment include: a drying temperature of 100-200℃ and a drying time of 2-8 hours; the conditions for the first calcination include: a calcination temperature of 450-650℃ and a calcination time of 2-6 hours. In step S2, the temperature of the second drying is 100-150℃; the activation treatment conditions include: temperature of 120-250℃; and time of 2-6 hours.

13. A method for hydrocracking feedstock oil rich in polycyclic aromatic hydrocarbons, characterized in that, The method includes: contacting the feedstock oil and hydrogen with the hydrocracking catalyst according to any one of claims 1-8 and carrying out a hydrocracking reaction, wherein the hydrocracking reaction is carried out using a fixed-bed single-stage series and diesel cycle process.

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