A diesel deep hydrodearomatization catalyst, its preparation method and application

Abstract

The present disclosure relates to a diesel deep hydrodearomatization catalyst, a preparation method and application thereof. The 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 1; wherein the N value of a to-be-tested molecular sieve is defined as the ratio of the adsorption amount of the to-be-tested molecular sieve to bicyclic aromatic hydrocarbons and derivatives thereof to the adsorption amount of a standard molecular sieve to bicyclic aromatic hydrocarbons and derivatives thereof, the standard molecular sieve is an 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 catalyst of the present disclosure can improve the conversion rate of polycyclic aromatic hydrocarbons in the diesel fraction, help deep de-aromatization of diesel, and improve the quality of diesel.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of catalysts, in particular, to a diesel deep hydrodearomatization catalyst and a preparation method and application thereof. BACKGROUND

[0002] With the gradual improvement of fuel oil quality standards, reducing the content of polycyclic aromatic hydrocarbons in diesel oil, especially in secondary processing diesel oil with high content of polycyclic aromatic hydrocarbons, has become the focus of attention of oil refining workers. Hydroprocessing can convert polycyclic aromatic hydrocarbons in diesel oil fraction into monocyclic aromatic hydrocarbons or naphthenes through hydrogenation saturation and selective ring-opening reaction, achieving the goal of reducing the content of polycyclic aromatic hydrocarbons; at the same time, it can also improve the cetane number and reduce the density of diesel product, further improving the quality of diesel. Polycyclic aromatic hydrocarbon hydrogenation catalysis is a typical heterogeneous catalytic process, and diffusion and adsorption performance is one of the key factors affecting the reaction activity and product distribution of polycyclic aromatic hydrocarbons.

[0003] Chinese patent document 201610288646.3 discloses a modified Y / ZSM-48 composite molecular sieve and a preparation method and application thereof. The modified Y / ZSM-48 composite molecular sieve has the following properties: total pore volume is 0.46-0.85 mL / g, preferably 0.50-0.80 mL / g; mesopore volume is 0.35-0.65 mL / g, preferably 0.40-0.60 mL / g; mesopore volume accounts for 55%-90% of the total pore volume, preferably 60%-80%. The modified Y / ZSM-48 composite molecular sieve has a larger size of mesopore distribution, which can provide more reaction space for macromolecules, and can realize the hydrogenation ring-opening conversion of polycyclic aromatic hydrocarbons in the hydrocracking process.

[0004] Chinese patent document 201610288647.8 discloses a modified Y-Beta composite molecular sieve and a preparation method and application thereof. The modified Y-Beta composite molecular sieve has the following characteristics: total pore volume is 0.56-1.25 mL / g, preferably 0.65-1.10 mL / g; mesopore volume is 0.45-0.95 mL / g, preferably 0.550-0.85 mLg; mesopore volume accounts for 55%-80% of the total pore volume, preferably 60%-75%. The modified molecular sieve can be used for the hydrogenation ring-opening conversion of polycyclic aromatic hydrocarbons in the hydrocracking process.

[0005] Chinese patent document 202110100233.9 discloses a diesel hydro-upgrading catalyst. The catalyst uses a mesoporous amorphous silicon aluminum with a pore volume of 0.51-0.70 mL / g in the range of 12-20 nm. The catalyst has a certain polycyclic aromatic hydrocarbon reactivity when processing poor quality catalytic diesel raw materials.

[0006] The catalysts above can achieve the hydrogenation ring-opening of polycyclic aromatic hydrocarbons to some extent, but the effect is still not ideal. SUMMARY

[0007] The purpose of the present disclosure is to provide a catalyst for deep hydroprocessing of diesel oil, so as to achieve the hydrogenation ring-opening of polycyclic aromatic hydrocarbons.

[0008] To achieve the above purpose, the first aspect of the present disclosure provides a diesel deep hydrodearomatization catalyst, which 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 1; wherein the N value of a to-be-tested molecular sieve is defined as the ratio of the adsorption amount of the to-be-tested molecular sieve to the adsorption amount of a standard molecular sieve to a double-ring aromatic hydrocarbon and its derivative, 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.

[0009] Optionally, the N value of the second molecular sieve is 1-10, preferably, the second molecular sieve has an N value of 1-5; optionally, the pore volume of the second molecular sieve is 0.4-0.8 cm 3 / g, and the acid density is 0.8-2.5 μmol / m 2 .

[0010] 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.

[0011] Optionally, the content of the composite molecular sieve in the carrier is 5-70% by weight, and the content of the heat-resistant inorganic oxide matrix is 30-95% by weight, based on the total weight of the carrier.

[0012] Optionally, the catalyst contains 50-85% 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, in terms of oxides.

[0013] 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, ultra-stable Y molecular sieve USY, partially amorphous USY, rare earth ultra-stable Y molecular sieve REUSY, titanium-containing Y molecular sieve, phosphorus-containing Y molecular sieve, and at least one of HY type molecular sieve, and de-aluminized 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, ultra-stable Y molecular sieve, rare earth ultra-stable 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 ITQ-40, ITQ-44, ITQ-37, ITQ-53, ITQ-54, OSB-1, and EMC-2; and the heat-resistant inorganic oxide matrix is selected from at least one of alumina, silica, and silica-alumina.

[0014] The second aspect of the present disclosure provides a method for preparing a catalyst, the method comprising:

[0015] S1, mixing the first molecular sieve, the second molecular sieve, the heat-resistant inorganic oxide matrix, and the auxiliary agent, then performing kneading and extrusion 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;

[0016] 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; and performing second drying and activation treatment on the impregnated carrier.

[0017] Optionally, the weight ratio of the first molecular sieve, the second molecular sieve, and the heat-resistant inorganic oxide matrix is 1-25:4-45:30-95.

[0018] Optionally, in step S1, the first drying treatment conditions include: a drying temperature of 80-300℃, preferably 100-200℃; a drying time of 1-12 hours, preferably 2-8 hours; and the first calcination conditions include: a calcination temperature of 350-850℃, preferably 450-650℃; a calcination time of 1-12 hours, preferably 2-6 hours; in step S2, the impregnation conditions include: an impregnation temperature of room temperature-150℃, and an impregnation time of 1-6 hours; the second drying conditions include: a temperature of 100-300℃, preferably 100-150℃; and a time of 2-8 hours; and the activation treatment conditions include: a temperature of 100-350℃, preferably 120-250℃; and a time of 1-12 hours, preferably 2-6 hours.

[0019] The third aspect of the present disclosure provides a method for deep hydroprocessing of diesel oil, wherein the diesel oil and hydrogen are contacted with the catalyst described above and subjected to a hydrocracking reaction

[0020] By the technical solution described above, the present disclosure improves the diffusion and adsorption performance of polycyclic aromatic hydrocarbon molecules in the diesel oil fraction on the catalyst by improving the matching of the pore structure and size of the active component molecular sieve of the catalyst with the polycyclic aromatic hydrocarbon reactant molecules, thereby improving the removal and conversion of polycyclic aromatic hydrocarbons in the diesel oil fraction. The catalyst of the present disclosure can improve the conversion rate of polycyclic aromatic hydrocarbons in the diesel oil fraction, which helps to deeply remove aromatic compounds in diesel oil and improve the quality of diesel oil.

[0021] Other features and advantages of the present disclosure will be described in detail in the subsequent specific embodiment part. Specific embodiment

[0022] The specific embodiment of the present disclosure is described in detail below. It should be understood that the specific embodiment described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0023] The first aspect of the present disclosure provides a deep hydrodearomatization catalyst for diesel oil, which 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 1; wherein the N value of a to-be-tested molecular sieve is defined as the ratio of the adsorption amount of the to-be-tested molecular sieve to the adsorption amount of the standard molecular sieve to the double-ring aromatic hydrocarbon and its derivatives, the standard molecular sieve is a HY molecular sieve, and the molar ratio of SiO2 and Al2O of the standard molecular sieve is 5.4 and the cell constant is 24.60 angstroms.

[0024] The N value of the present disclosure is obtained by the adsorption molar ratio test method, specifically: first, accurately measure the tetrahydronaphthalene solution (100 milliliters, room temperature), then add a certain amount of molecular sieve material (5 grams), seal and stir under the protection of inert gas (N2) at 1 atmosphere and 360℃ for 10 hours, then filter, reconstitute the filtrate, cool to room temperature, and then measure the solution volume again with a measuring cylinder to obtain the adsorption volume difference ΔV of the test molecular sieve. The calculation formula of N is:

[0025] N = (ΔV test molecular sieve * M test molecular sieve) / (ΔV Y type molecular sieve * MY type molecular sieve)

[0026] Wherein ΔVtest is the volume difference of adsorbing tetralin of the test molecular sieve and the standard molecular sieve, Mtest is the molar mass of the test molecular sieve and the standard molecular sieve.

[0027] The present disclosure realizes the screening of the catalyst acidic component molecular sieve through the N value, strengthens the matching degree of the molecular sieve pore structure and the polycyclic aromatic hydrocarbon reactant molecule, and can improve the hydrogenation conversion and removal of the polycyclic aromatic hydrocarbon, and can be used for the de-aromatic process of deep hydrogenation treatment of diesel, especially the poor diesel rich in polycyclic aromatic hydrocarbon.

[0028] According to the present disclosure, the N value of the second molecular sieve can be 1-10, preferably, the N value of the second molecular sieve is 1-5; optionally, the pore volume of the second molecular sieve can be 0.4-0.8 cm 3 / g, and the acid density can be 0.8-2.5 μmol / m 2 .

[0029] According to the present 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.

[0030] According to the present disclosure, the content of the composite molecular sieve in the carrier can be 5-70 wt%, and the content of the heat-resistant inorganic oxide matrix can be 30-95 wt% based on the total weight of the carrier.

[0031] According to the present disclosure, the catalyst can contain 50-85 wt% of the carrier, 1.5-6 wt% of the group VIII metal element, and 10-35 wt% of the group VIB metal element based on the total weight of the catalyst in terms of oxide.

[0032] According to the present disclosure, the first molecular sieve can be 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 molecular sieve; preferably, the first molecular sieve can 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 sieve; and the second molecular sieve can be selected from at least one of ITQ-40, ITQ-44, ITQ-37, ITQ-53, ITQ-54, OSB-1 and EMC-2.

[0033] In the present disclosure, the refractory inorganic oxide matrix can be selected from at least one of alumina, silica and silica-alumina. The alumina is selected from one or more of the transition phase aluminas of gamma, eta, theta, delta and chi, and can also be one or more of the transition phase aluminas of gamma, eta, theta, delta and chi containing one or more of the additives selected from silicon, titanium, magnesium, boron, zirconium, thorium, niobium and rare earths, preferably gamma-alumina and gamma-alumina containing one or more of the additives selected from silicon, phosphorus, titanium, magnesium, boron, zirconium, thorium, niobium and rare earths. They can be commercially available or obtained by any of the known methods. The silica-alumina preferably has a pseudo-boehmite structure and can be commercially available or prepared by any of the known methods. For example, the Siral series of commercially available silica-alumina having a pseudo-boehmite structure produced by Condea, Germany, can be used in the present disclosure.

[0034] The catalyst provided according to the present disclosure can be used in any reactor suitable for contacting the feed oil with the catalyst under hydroprocessing conditions. For example, the reaction can be carried out in a fixed bed reactor, a moving bed reactor or a ebullated bed reactor. Other types of hydrocarbon oil feedstocks can also be directly processed for hydroprocessing. The hydrocarbon oil feedstock can also be various heavy mineral oils or synthetic oils or mixed distillate oils, such as one or more selected from crude oil, distillate oil, solvent refined oil, wax paste, wax oil, Fischer-Tropsch synthetic oil, coal liquefied oil, light deasphalted oil and heavy deasphalted oil. The hydroprocessing dearomatization process is particularly suitable for diesel oil, especially poor quality diesel oil rich in polycyclic aromatic hydrocarbons.

[0035] The second aspect of the present disclosure provides a method for preparing a catalyst, which comprises:

[0036] S1, mixing the first molecular sieve, the second molecular sieve, the refractory inorganic oxide matrix and the aid, then kneading and extruding to obtain extruded strips; subjecting the extruded strips to first drying and first calcination to obtain a carrier; the aid is selected from at least one of inorganic binder and extrusion aid;

[0037] 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; subjecting the impregnated carrier to second drying and activation treatment.

[0038] According to the present disclosure, the weight ratio of the first molecular sieve, the second molecular sieve and the refractory inorganic oxide matrix can be 1-25:4-45:30-95.

[0039] According to the present disclosure, in step S1, the conditions of the first drying treatment include: a drying temperature of 80-300°C, preferably 100-200°C; a drying time of 1-12 hours, preferably 2-8 hours; the conditions of the first calcination include: a calcination temperature of 350-850°C, preferably 450-650°C; a calcination time of 1-12 hours, preferably 2-6 hours; in step S2, the conditions of the impregnation include: an impregnation temperature of room temperature-150°C, an impregnation time of 1-6 hours; the conditions of the second drying include: a temperature of 100-300°C, preferably 100-150°C; a time of 2-8 hours; the conditions of the activation treatment include: a temperature of 100-350°C, preferably 120-250°C; a time of 1-12 hours, preferably 2-6 hours.

[0040] The third aspect of the present disclosure provides a method for deep hydroprocessing of diesel oil, under hydrogenation conditions, diesel oil, especially poor diesel oil rich in polycyclic aromatic hydrocarbons, and hydrogen are contacted with the catalyst of the present disclosure, which can improve the hydrogenation conversion and removal of polycyclic aromatic hydrocarbons, and realize the deep hydroprocessing of diesel oil.

[0041] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited in any way by the examples.

[0042] Example 1

[0043] Example 1

[0044] Example 1

[0045] Example 2

[0046] Take 200.0 grams of pseudo-boehmite (Catalyst Changling Branch) with a dry basis of 70%, 28.2 grams of Y-type molecular sieve with a dry basis of 85%, and 43.9 grams of ITQ-37 molecular sieve with a dry basis of 82%, and add an appropriate amount of auxiliary agents containing inorganic binder and extrusion aid, etc. to mix uniformly, extrude into butterfly-shaped carrier strips with an inscribed circle diameter of 1.6 mm on the extruder, dry at 120°C for 3 hours, and calcine at 600°C for 4 hours to obtain carrier Z2.

[0047] Take 100 grams of carrier Z2, immerse in 81 ml of mixed solution containing WO3 271.6 g / L, NiO 24.7 g / L, and P2O5 12.3 g / L of ammonium metatungstate, nickel carbonate, and phosphoric acid, respectively, for 3 hours, dry at 120°C for 3 hours, and then activate at 200°C for 3 hours to obtain catalyst C2. The theoretical composition is shown in Table 2.

[0048] Example 3

[0049] Take 200.0 grams of pseudo-boehmite (Catalyst Changling Branch) with a dry basis of 70%, 28.2 grams of Y-type molecular sieve with a dry basis of 85%, and 43.9 grams of ITQ-37 molecular sieve with a dry basis of 82%, and add an appropriate amount of auxiliary agents containing inorganic binder and extrusion aid, etc. to mix uniformly, extrude into butterfly-shaped carrier strips with an inscribed circle diameter of 1.6 mm on the extruder, dry at 120°C for 3 hours, and calcine at 600°C for 4 hours to obtain carrier Z3.

[0050] Take 100 grams of carrier Z3, immerse in 95 ml of mixed solution containing WO3 231.6 g / L, NiO 21.1 g / L, and P2O5 10.5 g / L of ammonium metatungstate, nickel carbonate, and phosphoric acid, respectively, for 3 hours, dry at 120°C for 3 hours, and then activate at 200°C for 3 hours to obtain catalyst C3. The theoretical composition is shown in Table 2.

[0051] Example 4

[0052] Take 100 grams of carrier Z2, immerse in 81 ml of mixed solution containing WO3 271.6 g / L, NiO 24.7 g / L, and P2O5 12.3 g / L of ammonium metatungstate, nickel carbonate, and phosphoric acid, respectively, for 3 hours, dry at 120°C for 3 hours, and then activate at 200°C for 3 hours to obtain catalyst C2. The theoretical composition is shown in Table 2.

[0053] Example 5

[0054] Take 100 grams of carrier Z2, and immerse it in 81 ml of mixed solution containing WO3 543.2 g / L, NiO 111.1 g / L, and P2O5 24.7 g / L of ammonium metatungstate, basic nickel carbonate, and phosphoric acid respectively for 3 hours. Dry it at 120°C for 3 hours, and then activate it at 200°C for 3 hours to obtain catalyst C5. The theoretical composition is shown in Table 2.

[0055] Example 6

[0056] Take 100 grams of carrier Z2, and immerse it in 81 ml of mixed solution containing MoO3 185.2 g / L, NiO 24.7 g / L, and P2O5 12.3 g / L of molybdenum trioxide, basic nickel carbonate, and phosphoric acid respectively for 3 hours. Dry it at 120°C for 3 hours, and then activate it at 200°C for 3 hours to obtain catalyst C6. The theoretical composition is shown in Table 2.

[0057] Example 7

[0058] Take 200.0 grams of pseudo-boehmite with a dry basis of 70% (Catalyst Changling Branch), 28.2 grams of Y-type molecular sieve with a dry basis of 85%, and 44.4 grams of OSB molecular sieve with a dry basis of 81%, and add an appropriate amount of additives containing inorganic binder and extrusion aid, etc. Mix them uniformly, and extrude them into butterfly-shaped carrier strips with an outer circle diameter of 1.6 mm on an extruder. Dry them at 120°C for 3 hours, and then calcine them at 600°C for 4 hours to obtain carrier Z7.

[0059] Take 100 grams of carrier Z7, and immerse it in 83 ml of mixed solution containing WO3 265.1 g / L, NiO 24.1 g / L, and P2O5 12.0 g / L of ammonium metatungstate, basic nickel carbonate, and phosphoric acid respectively for 3 hours. Dry it at 120°C for 3 hours, and then activate it at 200°C for 3 hours to obtain catalyst C7. The theoretical composition is shown in Table 2.

[0060] Example 8

[0061] Take 114.3 grams of pseudo-boehmite with a dry basis of 70% (Catalyst Changling Branch), 28.2 grams of Y-type molecular sieve with a dry basis of 85%, 44.4 grams of OSB molecular sieve with a dry basis of 81%, and 78.9 grams of amorphous silica-alumina material (Siral 40 of Condea Company, Germany) with a dry basis of 76%, and add an appropriate amount of additives containing inorganic binder and extrusion aid, etc. Mix them uniformly, and extrude them into butterfly-shaped carrier strips with an outer circle diameter of 1.6 mm on an extruder. Dry them at 120°C for 3 hours, and then calcine them at 600°C for 4 hours to obtain carrier Z8.

[0062] Take 100 grams of carrier Z8, and immerse in 85 milliliters of mixed solution containing 258.8 grams / liter of WO3, 23.5 grams / liter of NiO, and 11.8 grams / liter of P2O5, respectively, of ammonium metatungstate, basic nickel carbonate, and phosphoric acid for 3 hours, dry at 120°C for 3 hours, and then activate and calcine at 200°C for 3 hours to obtain catalyst C8. The theoretical composition is shown in Table 2, based on the catalyst.

[0063] Example 9

[0064] Take 100 grams of carrier Z8, and immerse in 85 milliliters of mixed solution containing 258.8 grams / liter of WO3, 23.5 grams / liter of NiO, and 11.8 grams / liter of P2O5, respectively, of ammonium metatungstate, basic nickel carbonate, and phosphoric acid for 3 hours, dry at 120°C for 3 hours, and then activate and calcine at 200°C for 3 hours to obtain catalyst C8. The theoretical composition is shown in Table 2, based on the catalyst.

[0065] Take 100 grams of carrier Z8, and immerse in 85 milliliters of mixed solution containing 258.8 grams / liter of WO3, 23.5 grams / liter of NiO, and 11.8 grams / liter of P2O5, respectively, of ammonium metatungstate, basic nickel carbonate, and phosphoric acid for 3 hours, dry at 120°C for 3 hours, and then activate and calcine at 200°C for 3 hours to obtain catalyst C8. The theoretical composition is shown in Table 2, based on the catalyst.

[0066] Example 9

[0067] Take 100 grams of carrier Z8, and immerse in 85 milliliters of mixed solution containing 258.8 grams / liter of WO3, 23.5 grams / liter of NiO, and 11.8 grams / liter of P2O5, respectively, of ammonium metatungstate, basic nickel carbonate, and phosphoric acid for 3 hours, dry at 120°C for 3 hours, and then activate and calcine at 200°C for 3 hours to obtain catalyst C8. The theoretical composition is shown in Table 2, based on the catalyst.

[0068] Take 100 grams of carrier Z8, and immerse in 85 milliliters of mixed solution containing 258.8 grams / liter of WO3, 23.5 grams / liter of NiO, and 11.8 grams / liter of P2O5, respectively, of ammonium metatungstate, basic nickel carbonate, and phosphoric acid for 3 hours, dry at 120°C for 3 hours, and then activate and calcine at 200°C for 3 hours to obtain catalyst C8. The theoretical composition is shown in Table 2, based on the catalyst.

[0069] Comparative Example 1

[0070] Take 200.0 grams of pseudo-boehmite (Catalyst Branch Co., Ltd. of Changling) with dry basis of 70% and 70.6 grams of Y-type molecular sieve (Catalyst Branch Co., Ltd. of Changling, cell constant 24.60 A) with dry basis of 85%, and add a proper amount of auxiliary agents containing inorganic binder and extrusion aid, etc. to mix uniformly, extrude into butterfly-shaped carrier strips with an outer circle diameter of 1.6 mm on an extruder, and dry at 120°C for 3 hours and calcine at 600°C for 4 hours to obtain carrier DZ.

[0071] Take 100 grams of carrier DZ, and immerse in 78 ml of mixed solution containing 282.1 grams / liter of ammonium metatungstate, 25.6 grams / liter of basic nickel carbonate and 12.8 grams / liter of phosphoric acid, respectively, for 3 hours, dry at 120°C for 3 hours, and activate at 200°C for 3 hours to obtain catalyst DC. The theoretical composition is shown in Table 2.

[0072] Table 1

[0073] Molecular sieve number Pore volume / (cm 3 / g) Acid density / (mmol / m 2 )]]> N value ITQ-37 0.501 2.122 1.79 OSB-1 0.611 1.711 1.45 Y 0.412 3.121 1.00

[0074] Table 2

[0075]

[0076]

[0077] Test Example

[0078] Take catalytic cracking diesel oil with a density of 0.9561 g / cm 3 , sulfur content of 9800 ppm, nitrogen content of 743 ppm and total aromatic hydrocarbon content of 85.7% as raw material, and evaluate the performances of catalysts C1, C2, C3, C7 and DC on a 30 ml fixed bed device. The specific method is as follows: fill industrial refining catalyst on the upper part of the bed and catalyst on the lower part, and the loading amount of catalyst is 15 ml. Before feeding the raw oil, the catalyst is pre-sulfided, and the sulfiding conditions are as follows: sulfiding at 110°C for 2 hours and at 300°C for 4 hours, and the sulfiding oil is kerosene containing 6% by weight of carbon disulfide. The reaction conditions in the hydrogenation refining reaction zone are as follows: reaction temperature 350°C, hydrogen partial pressure 6.5 MPa, liquid hourly space velocity 1.5 h -1 , hydrogen to oil volume ratio 800. The reaction conditions in the hydrotreating reaction zone are as follows: reaction temperature 370°C, hydrogen partial pressure 6.5 MPa, modifier liquid hourly space velocity 1.2 h -1 , hydrogen to oil volume ratio 800.

[0079] The test results are shown in Table 3.

[0080] Table 3

[0081] Catalyst C1 C2 C3 C7 DC Aromatics removal % above bicyclo 75％ 82％ 78％ 85％ 70％ Cetane index improvement Baseline + 0.4 Baseline + 0.5 Baseline + 0.4 Baseline + 0.6 Baseline

[0082] The test results in Table 3 show that the catalysts of the present disclosure have higher removal rates of polycyclic aromatic hydrocarbons, and when applied to deep hydrodearomatization of diesel oil, the polycyclic aromatic hydrocarbon content in the diesel oil product is lower, and the cetane number is higher.

[0083] The preferred embodiments of the present disclosure are described in detail above, but the present disclosure is not limited to the specific details in the above-described embodiments, and various simple modifications can be made to the technical solutions of the present disclosure within the technical concept of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0084] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present disclosure will not further describe various possible combination manners.

[0085] In addition, various different embodiments of the present disclosure can also be combined in any manner, as long as it does not deviate from the idea of the present disclosure, and it should also be considered as disclosed by the present disclosure.

Claims

1. A catalyst for deep hydrotreating and dearomatizing diesel fuel, characterized in that, The catalyst comprises a support and an active metal component loaded 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 of 1-10 and 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 ITQ-40 molecular sieve, ITQ-44 molecular sieve, ITQ-37 molecular sieve, ITQ-53 molecular sieve, ITQ-54 molecular sieve, OSB-1 molecular sieve, and EMC-2 molecular sieve. 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. The standard molecular sieve is HY molecular sieve, and the molar ratio of SiO2 to Al2O3 in the standard molecular sieve is 5.4, and the cell constant is 24.60 Å. The weight ratio of the first molecular sieve to the second molecular sieve in the composite molecular sieve is 1:9-9:1; Based on the total weight of the catalyst, and calculated as oxides, the catalyst contains 50-85% by weight of support, 1.5-6% by weight of Group VIII metal elements, and 10-35% by weight of Group VIB metal elements. The N value was obtained through an adsorption molar ratio test method, specifically: 100 mL of tetrahydronaphthalene solution was accurately measured at room temperature, then 5 g of molecular sieve material was added. The mixture was then sealed and stirred at 360°C under inert gas N2 protection for 1 atmosphere for 10 hours. After filtration, the filtrate was re-diluted to the required volume, cooled to room temperature, and the solution volume was measured again using a graduated cylinder to obtain the adsorption volume difference ΔV of the tested molecular sieve. The formula for calculating N is: N = (ΔV test molecular sieve × M test molecular sieve) / (ΔVY type molecular sieve × MY type molecular sieve); Wherein, ΔV test molecular sieve and ΔVY type molecular sieve are the volume differences of adsorbed tetrahydronaphthalene between the test molecular sieve and the standard molecular sieve, respectively, and M test molecular sieve and MY type molecular sieve are the molar masses of the test molecular sieve and the standard molecular sieve, respectively.

2. The catalyst according to claim 1, wherein, The second molecular sieve has an N value of 1-5.

3. The 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 1:1 to 9:

1.

4. The catalyst according to claim 1, wherein, Based on the total weight of the carrier, the content of composite molecular sieve in the carrier is 5-70% by weight, and the content of heat-resistant inorganic oxide matrix is ​​30-95% by weight.

5. The catalyst according to claim 1, wherein, 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 and phosphorus-containing Y molecular sieve. The heat-resistant inorganic oxide matrix is ​​selected from at least one of alumina, silicon oxide, and silicon-alumina.

6. A method for preparing the catalyst according to any one of claims 1-5, 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.

7. The method according to claim 6, wherein, The weight ratio of the first molecular sieve, the second molecular sieve, and the heat-resistant inorganic oxide matrix is ​​1-25:4-45:30-95.

8. The method according to claim 6, 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.

9. The method according to claim 8, 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 conditions for the second drying include a temperature of 100-150°C; the conditions for the activation treatment include a temperature of 120-250°C and a time of 2-6 hours.

10. A method for deep hydrotreating diesel fuel, characterized in that, The diesel and hydrogen are contacted with the catalyst described in any one of claims 1-5 and subjected to a hydrocracking reaction.

Images