A high-activity gasoline and diesel fraction selective hydrogenation catalyst and its preparation method and application

Abstract

The present invention relates to the technical field of hydrogenation catalysis, and more specifically, to a high-activity gasoline and diesel fraction selective hydrogenation catalyst and its preparation method and application, with the purpose of overcoming the defects of traditional γ-Al2O3 carriers and nitrogen-containing heteroatom carbon material carriers. One of the purposes of the present invention is to provide a method for preparing a high-activity gasoline and diesel fraction selective hydrogenation catalyst, comprising the following steps: depositing active components on a carbon material / γ-Al2O3 composite carrier, drying and calcining to obtain a high-activity gasoline and diesel fraction selective hydrogenation catalyst; the active components include metal salts and co-metal salts; the metal salts and co-metal salts exist in the form of metal oxides in the precursor of the high-activity gasoline and diesel fraction selective hydrogenation catalyst. Secondly, a high-activity gasoline and diesel fraction selective hydrogenation catalyst is also provided, as well as the application of the catalyst in products such as straight-run gasoline fraction, straight-run diesel fraction, and coking gasoline fraction.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogenation catalysis, and more specifically to a high-activity gasoline and diesel fraction selective hydrogenation catalyst, and a preparation method and application thereof. Background Art

[0002] Since the world's first set of technology, later known as "classical hydrogenation", was industrialized in Germany in 1926, hydrogenation technology has gone through nearly a century of development. In particular, in the past fifty years, hydrogenation technology has developed rapidly as an important means to produce more gasoline, diesel and other high-quality middle distillates.

[0003] Since the successful industrial application of Mo or W catalysts promoted by Co or Ni, the space for improving catalyst activity by adjusting the active phase components has become increasingly narrow. Relevant research on hydrogenation catalyst carriers has found that the surface properties of the carrier can affect the electronic and morphological structure of the latter through the interaction with the active components, thereby ultimately affecting the catalytic performance of the catalyst. Therefore, the current research on oil hydrogenation catalysts is mainly focused on improving the active phase structure by adjusting the properties of the carrier to improve the catalyst hydrodesulfurization activity, and many new hydrogenation catalysts and their preparation methods have emerged one after another.

[0004] γ-Al2O3 has become the most mainstream carrier component of hydrogenation catalysts due to its advantages such as easy-to-adjust pore structure, high bulk density, high mechanical strength, good stability and suitable acidity; however, it has too strong interaction with metal active components. Although this effect is conducive to the dispersion of active components, it will form a spinel structure with metals such as Ni and Co, hindering the subsequent sulfidation of the metal active phase and thus reducing the hydrogenation activity of the catalyst. In addition, the existence of the spinel structure also hinders the accessibility of the auxiliary metals Co and Ni to the main active phase metals Mo and W, thereby hindering the formation of highly active Co(Ni)Mo(W)S active phase; in recent years, research on the application of carbon-based carriers in oil hydrogenation catalysts has developed rapidly, but it is undeniable that so far no oil hydrogenation catalyst prepared with pure carbon materials as carriers has been successfully applied in industry. The reason is that carbon materials still have many shortcomings that need to be optimized: first, the preparation method of efficient carbon carriers is generally cumbersome and costly. Secondly, carbon materials themselves still have disadvantages such as poor mechanical strength and low bulk density. Therefore, it is crucial to overcome the respective disadvantages of the two carriers, couple their advantages, and play the role of 1+1>2.

[0005] "Reduce oil and increase chemical production" is the main theme of the future refining industry. Exploring oil conversion pathways in the field of hydrogenation, one of the most important secondary processing processes in modern refining enterprises, has important theoretical and practical significance. In the early stage, the production of National V and National VI clean oil products was the guide, and the hydrogenation process mainly focused on the removal of impurity elements represented by S and N in the raw materials. Therefore, we have been committed to how to further improve the hydrogenation activity of hydrogenation catalysts. At present, commercial hydrogenation catalysts have basically achieved the "surplus" of hydrogenation activity, but ignored the "excess" hydrogenation performance, which will lead to the oversaturation of cyclic hydrocarbons represented by aromatics. This will not only increase the chemical hydrogen consumption in the entire hydrogenation process and increase the production cost of the enterprise, but also lead to the low-value conversion of a large number of high-value aromatics, reducing the efficiency of the enterprise. Therefore, how to take the core hydrogenation catalyst of the entire hydrogenation process as a breakthrough, through the adjustment of the catalyst structure, under the premise of ensuring the hydrogenation efficiency, adjust the path selectivity of the hydrogenation process, enhance the selectivity of the direct desulfurization (DDS) path, inhibit the selectivity of the hydrogenation saturation (HYD) path, realize the directional conversion of reactant molecules, and enrich the production of high-value aromatics is the key technology that urgently needs to be developed and applied in the current hydrogenation field. Summary of the invention

[0006] In order to overcome at least one of the defects of the above-mentioned prior art, the purpose of the present invention is to provide a high-activity gasoline and diesel fraction selective hydrogenation catalyst and its preparation method and application, so as to overcome the defects of traditional γ-Al2O3 carriers and nitrogen-containing heteroatom carbon material carriers, avoid excessively strong interaction between the active phase and the alumina carrier, and improve the catalytic performance.

[0007] One of the purposes of the present invention is to provide a method for preparing a high-activity gasoline and diesel fraction selective hydrogenation catalyst, comprising the following steps: depositing active components on a carbon material / γ-Al2O3 composite carrier, drying and calcining to obtain the high-activity gasoline and diesel fraction selective hydrogenation catalyst;

[0008] The active components include metal salts and auxiliary metal salts; the metal salts and auxiliary metal salts exist in the form of metal oxides in the precursor of the high-activity gasoline and diesel fraction selective hydrogenation catalyst.

[0009] Furthermore, the preparation method of the highly active gasoline and diesel fraction selective hydrogenation catalyst comprises the following steps:

[0010] S1: dissolving the metal salt and the auxiliary metal salt in a solvent to prepare an impregnation solution;

[0011] S2: adding the impregnation solution dropwise to the carbon material / γ-Al2O3 composite carrier to obtain a catalyst semi-finished product;

[0012] S3: leaving the semi-finished catalyst product to stand in the air, drying it, and calcining it at 200-800° C. in an inert gas atmosphere for 2-8 hours to obtain the highly active gasoline and diesel fraction selective hydrogenation catalyst.

[0013] Preferably, in step S2, the amount of the impregnation solution used is the same as the saturated adsorption capacity of the carbon material / γ-Al2O3 composite carrier.

[0014] In some embodiments, the preparation method of the carbon material / γ-Al2O3 composite carrier is as follows: pseudo-boehmite is calcined to obtain γ-Al2O3, the γ-Al2O3 is placed in a pyrolysis device, and then one or two of olefins, alkanes or alkynes are carried into the pyrolysis device by an inert gas and pyrolyzed simultaneously to obtain an intermediate carrier, and then one or two of pyridine, pyrrole, ammonia, and amines are introduced into the pyrolysis device, and the surface of the intermediate carrier is modified under high temperature conditions to obtain a carbon material / γ-Al2O3 composite carrier.

[0015] In other embodiments, the preparation method of the carbon material / γ-Al2O3 composite carrier is as follows: pseudo-boehmite is placed in a pyrolysis device, one or two of olefins, alkanes or alkynes are directly carried into the pyrolysis device by an inert gas and pyrolysis and crystallization are simultaneously performed to obtain an intermediate carrier, and then one or two of pyridine, pyrrole, ammonia, and amines are introduced into the pyrolysis device, and the surface of the intermediate carrier is modified under high temperature conditions to obtain a carbon material / γ-Al2O3 composite carrier.

[0016] In some other embodiments, the preparation method of the carbon material / γ-Al2O3 composite carrier is as follows: using pseudo-boehmite or γ-Al2O3 as a pre-carrier, preparing nitrogen-containing organic matter into a solution and loading it on the surface of the pre-carrier and then performing pyrolysis treatment to obtain the carbon material / γ-Al2O3 composite carrier.

[0017] Furthermore, when γ-Al2O3 is used as a precursor, the preparation method of the precursor is: the pseudo-boehmite is heated to 400-600°C at a rate of 2-6°C / min and then maintained for 2-4h to obtain powdered γ-Al2O3, and the powdered γ-Al2O3 is crushed and sieved to obtain a γ-Al2O3 precursor.

[0018] Furthermore, the nitrogen-containing organic matter is one or more of pyridine, pyrrole, urea, o-phenanthroline, melamine, and polyvinyl pyrrolidone.

[0019] Another object of the present invention is to provide a high-activity gasoline and diesel fraction selective hydrogenation catalyst prepared based on the above preparation method.

[0020] Furthermore, in the highly active gasoline and diesel fraction selective hydrogenation catalyst, the metal ion of the metal salt is a tungsten ion, and the metal ion of the auxiliary metal salt is a nickel ion.

[0021] Preferably, the particle size of NiWO4 in the high-activity gasoline and diesel fraction selective hydrogenation catalyst is 16-27 nm.

[0022] Preferably, in the highly active gasoline and diesel fraction selective hydrogenation catalyst, the proportions of tungsten in different chemical states to the total tungsten are: WO3 18-32%, NiWO4 47-63%, Al2(WO4)3 19-21%.

[0023] Preferably, in the highly active gasoline and diesel fraction selective hydrogenation catalyst, the ratio of nickel in different chemical states to the total nickel is: Al2NiO4 14-31%, NiWO4 39-55%, NiO 28-40%.

[0024] Another object of the present invention is to provide a catalyst prepared based on the above method for use in the hydrogenation treatment of straight-run gasoline, straight-run diesel fraction, coker gasoline, coker diesel fraction, catalytic cracking gasoline, catalytic cracking diesel fraction and wax oil.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] Firstly, the preparation method of the present invention provides a metal active phase component / carbon material / γ-Al2O3 multilayer catalyst system, by modifying the surface of the carbon material carrier with N heteroatoms to generate metal component anchor points of suitable strength, and by controlling the directional deposition of the metal active phase component to optimize the catalyst active phase structure, thereby realizing the preparation and application of a high-activity gasoline and diesel fraction selective hydrogenation catalyst; secondly, the present invention organically matches and couples the traditional γ-Al2O3 carrier and the nitrogen-containing heteroatom carbon material carrier to overcome their respective shortcomings, prevent excessive interaction between the active phase and the alumina carrier, significantly reduce the spinel structure content, and promote the oxidized active phase metal to form Ni(Co)W(Mo)S, an important precursor Ni(Co)W(Mo)O4, and at the same time, due to the anchor point and electronic regulation of N, the dispersion of the precursor is effectively improved, and the hydrogenation reaction path is regulated, thereby greatly improving the yield of high-value aromatics in real oil products. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a bar chart comparing the hydrodesulfurization effects of the catalysts prepared in Examples 1-3 and 8.

[0028] Figure 2 This is a bar chart comparing the hydrodesulfurization effects of the catalysts prepared in Examples 4-8 and Comparative Examples 1-4.

[0029] Figure 3 The XRD diffraction patterns of the catalysts prepared in Example 5 and Comparative Examples 1-2 are shown.

[0030] Figure 4 It is the W4f orbital peak energy spectrum diagram of the catalysts prepared in Example 5 and Comparative Examples 1-2.

[0031] Figure 5 Ni2p orbital energy spectra of the catalysts prepared in Example 5 and Comparative Examples 1-2. DETAILED DESCRIPTION

[0032] The primary purpose of the present invention is to provide a method for preparing a high-activity gasoline and diesel fraction selective hydrogenation catalyst, specifically: depositing active components on a carbon material / γ-Al2O3 composite carrier, drying and calcining to obtain the high-activity gasoline and diesel fraction selective hydrogenation catalyst; wherein the active components include metal salts and co-metal salts, and the metal salts and co-metal salts exist in the form of metal oxides in the precursor of the high-activity gasoline and diesel fraction selective hydrogenation catalyst.

[0033] In a more specific embodiment, the method for preparing a highly active gasoline and diesel fraction selective hydrogenation catalyst comprises the following steps:

[0034] S1: dissolving the metal salt and the auxiliary metal salt in a solvent to prepare an impregnation solution;

[0035] S2: adding the impregnation solution dropwise to the carbon material / γ-Al2O3 composite carrier to obtain a catalyst semi-finished product;

[0036] S3: leaving the semi-finished catalyst product to stand in the air, drying it, and calcining it at 200-800° C. in an inert gas atmosphere for 2-8 hours to obtain the highly active gasoline and diesel fraction selective hydrogenation catalyst.

[0037] In order to improve the performance of the catalyst and avoid unnecessary waste of raw materials, in a preferred embodiment, in step S1, the amount of the impregnation solution is the same as the saturated adsorption capacity of the carbon material / γ-Al2O3 composite carrier.

[0038] In a preferred embodiment, step S3 is specifically as follows: placing the catalyst semi-finished product in the air for 10-15 hours, drying it at 70-90°C, then heating it to 200-800°C at a rate of 8-12°C / min, and calcining it in a nitrogen atmosphere for 2-8 hours to obtain the highly active gasoline and diesel fraction selective hydrogenation catalyst.

[0039] When dissolving the metal salt and the auxiliary metal salt to obtain the impregnation solution, a conventional good solvent is usually selected.

[0040] Specifically, for example, a suitable amount of water is used for dissolution.

[0041] In some embodiments, in the precursor of the high-activity gasoline and diesel fraction selective hydrogenation catalyst, the content of the metal oxide is 5-30%, and the content of the co-metal oxide is 2-15%.

[0042] More specifically, the metal ions of the metal salt are molybdenum ions and / or tungsten ions; the metal ions of the auxiliary metal salt are one or more of cobalt ions, nickel ions, zinc ions, potassium ions, copper ions, silver ions, platinum ions, and palladium ions.

[0043] In some embodiments, the carbon material / γ-Al2O3 composite carrier is prepared in the following manner: pseudo-boehmite is calcined to obtain γ-Al2O3, the γ-Al2O3 is placed in a pyrolysis device, and then one or two of olefins, alkanes or alkynes are carried into the pyrolysis device by an inert gas and pyrolyzed simultaneously to obtain an intermediate carrier, and then one or two of pyridine, pyrrole, ammonia, and amines are introduced into the pyrolysis device, and the surface of the intermediate carrier is modified under high temperature conditions to obtain a carbon material / γ-Al2O3 composite carrier.

[0044] In order to improve the performance, in the step of preparing γ-Al2O3 using pseudo-boehmite, the calcination temperature is 400-600°C, and the calcination time is 2-4h; and / or, in the step of preparing an intermediate carrier through γ-Al2O3, the pyrolysis temperature is 600-800°C; and / or, in the step of preparing a carbon material / γ-Al2O3 composite carrier through the intermediate carrier, the temperature is 600-800°C.

[0045] In order to streamline the process, in other embodiments, the carbon material / γ-Al2O3 composite carrier is prepared in the following manner: pseudo-boehmite is placed in a pyrolysis device, one or two of olefins, alkanes or alkynes are directly carried into the pyrolysis device by an inert gas and pyrolyzed and crystallized simultaneously to obtain an intermediate carrier, and then one or two of pyridine, pyrrole, ammonia, and amines are introduced into the pyrolysis device, and the surface of the intermediate carrier is modified under high temperature conditions to obtain a carbon material / γ-Al2O3 composite carrier.

[0046] In order to improve the performance of the composite carrier, in the step of using pseudo-boehmite to prepare the intermediate carrier, the calcination temperature is 600℃-800℃, and / or, in the step of preparing the carbon material / γ-Al2O3 composite carrier through the intermediate carrier, the temperature is 600-800℃.

[0047] In some other embodiments, the carbon material / γ-Al2O3 composite carrier can also be prepared in the following manner: using pseudo-boehmite or γ-Al2O3 as a precursor, preparing nitrogen-containing organic matter into a solution and loading it on the surface of the precursor, followed by pyrolysis treatment, to obtain the carbon material / γ-Al2O3 composite carrier.

[0048] In an optional embodiment, when γ-Al2O3 is used as a precursor, the preparation method of the precursor is as follows: the pseudo-boehmite is heated to 400-600°C at a rate of 2-6°C / min and maintained for 2-4 hours to obtain powdered γ-Al2O3, and the powdered γ-Al2O3 is crushed and sieved to obtain a γ-Al2O3 precursor; preferably, the particle size of the γ-Al2O3 precursor is 20-40 mesh.

[0049] In some embodiments, the pyrolysis treatment conditions are: under the protection of inert gas, heating to 400-800° C. at a rate of 5-15° C. / min, and then calcining for 2-4 hours.

[0050] In some embodiments, the nitrogen-containing organic matter is selected from one or more of pyridine, pyrrole, urea, o-phenanthroline, melamine, and polyvinyl pyrrolidone. Preferably, urea or polyvinyl pyrrolidone is selected as the nitrogen source of the composite carrier, and more preferably, o-phenanthroline is selected.

[0051] In some preferred embodiments, the ratio of the nitrogen-containing organic matter to the pre-carrier is (0.1-0.5):7.5 by weight. Specifically, for example, the weight ratio of o-phenanthroline to the γ-Al2O3 pre-carrier is (0.1-0.5):7.5, more preferably (0.2-0.4):7.5. In specific implementation, it can be a numerical ratio of 0.1:7.5, 0.2:7.5, 0.3:7.5, 0.4:7.5, 0.5:7.5, etc. The test results show that when this range ratio is selected, the prepared catalyst has a better hydrodesulfurization effect. When the dosage is lower or higher than this ratio, the hydrodesulfurization effect decreases to varying degrees.

[0052] The present invention also provides a high-activity gasoline and diesel fraction selective hydrogenation catalyst prepared based on the above preparation method. In the high-activity gasoline and diesel fraction selective hydrogenation catalyst, the metal ion of the metal salt is tungsten ion, and the metal ion of the auxiliary metal salt is nickel ion.

[0053] Preferably, the particle size of NiWO4 in the high-activity gasoline and diesel fraction selective hydrogenation catalyst is 16-27nm; in the high-activity gasoline and diesel fraction selective hydrogenation catalyst, the proportion of tungsten in different chemical states to the total tungsten is: WO3 18-32%, NiWO4 47-63%, Al2(WO4)3 19-21%; preferably, in the high-activity gasoline and diesel fraction selective hydrogenation catalyst, the proportion of nickel in different chemical states to the total nickel is: Al2NiO4 14-31%, NiWO4 39-55%, NiO 28-40%.

[0054] Based on the above parameters, the high-activity gasoline and diesel fraction selective hydrogenation catalyst can show better effects in important indicators such as desulfurization rate, octane number and final product aromatic content when performing hydrogenation catalysis on gasoline and diesel fractions.

[0055] The content of the present invention is further described below in conjunction with specific examples, but it should not be construed as limiting the present invention. If not specifically indicated, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0056] Example 1

[0057] 20g of pseudo-boehmite was placed in a muffle furnace and heated to 600℃ at a rate of 4℃ / min and then maintained for 2h to obtain powdered γ-Al2O3, which was then pressed into tablets at a pressure of 10Mpa and crushed and sieved to obtain a 20-40 mesh γ-Al2O3 carrier;

[0058] 0.5 g of polyvinyl pyrrolidone (PVP, molecular weight 24000) was dissolved in 6 g of anhydrous ethanol, and then an equal volume of the solution was impregnated on 7.5 g of γ-Al2O3 carrier. After drying, the temperature was raised to 600 ° C at a rate of 10 ° C / min under nitrogen protection, and then naturally cooled after 2 hours to obtain a composite nitrogen-doped carbon material carrier.

[0059] Dissolve 3.15g of ammonium metatungstate and 1.28g of nickel nitrate in water to prepare an impregnation solution;

[0060] The impregnation liquid was dropped onto 7.5 g of the nitrogen-doped carbon material carrier, cured at room temperature for 12 h, dried in an oven at 80°C, then heated at a rate of 10°C / min, and calcined at 400°C under nitrogen protection for 4 hours to obtain a highly active gasoline and diesel fraction selective hydrogenation catalyst PVP-1.

[0061] Example 2

[0062] The difference between this embodiment and embodiment 1 is that polyvinyl pyrrolidone (PVP, molecular weight 24000) is replaced with polyvinyl pyrrolidone (PVP, molecular weight 50000), and other conditions are exactly the same, to prepare a highly active gasoline and diesel fraction selective hydrogenation catalyst PVP-2.

[0063] Example 3

[0064] 20g of pseudo-boehmite was placed in a muffle furnace and heated to 600℃ at a rate of 4℃ / min and then maintained for 2h to obtain powdered γ-Al2O3, which was then pressed into tablets at a pressure of 10Mpa and crushed and sieved to obtain a 20-40 mesh γ-Al2O3 carrier;

[0065] 0.5 g of urea was dissolved in 6 g of deionized water to prepare a solution, and then an equal volume of the solution was impregnated on 7.5 g of the above-mentioned γ-Al2O3 carrier. After drying, the solution was heated to 600°C at a rate of 10°C / min under nitrogen protection, and then cooled naturally after being retained for 2 hours to obtain a composite nitrogen-doped carbon material carrier.

[0066] Dissolve 3.15g of ammonium metatungstate and 1.28g of nickel nitrate in water to prepare an impregnation solution;

[0067] The impregnation liquid was dropped onto 7.5 g of the nitrogen-doped carbon material carrier, cured at room temperature for 12 hours, dried in an oven at 80°C, then heated at a rate of 10°C / min, and calcined at 400°C under nitrogen protection for 4 hours to obtain a highly active gasoline and diesel fraction selective hydrogenation catalyst NS.

[0068] Example 4

[0069] 20g of pseudo-boehmite was placed in a muffle furnace and heated to 600℃ at a rate of 4℃ / min and then maintained for 2h to obtain powdered γ-Al2O3, which was then pressed into tablets at a pressure of 10Mpa and crushed and sieved to obtain a 20-40 mesh γ-Al2O3 carrier;

[0070] 100 mg of o-phenanthroline was dissolved in 6 g of anhydrous ethanol to prepare a solution, and then an equal volume of the solution was impregnated on 7.5 g of the above-mentioned γ-Al2O3 carrier. After drying, the temperature was raised to 600°C at a rate of 10°C / min under nitrogen protection, and then naturally cooled after being retained for 2 hours to obtain a composite nitrogen-doped carbon material carrier.

[0071] Dissolve 3.15g of ammonium metatungstate and 1.28g of nickel nitrate in water to prepare an impregnation solution;

[0072] The impregnation liquid was dropped onto 7.5 g of the nitrogen-doped carbon material carrier, cured at room temperature for 12 h, dried in an oven at 80°C, then heated at a rate of 10°C / min, and calcined at 400°C under nitrogen protection for 4 hours to obtain the highly active gasoline and diesel fraction selective hydrogenation catalyst, namely NC-100.

[0073] Example 5

[0074] The difference between this example and example 4 is that the amount of o-phenanthroline is changed to 200 mg, and other conditions are exactly the same, to prepare a highly active gasoline and diesel fraction selective hydrogenation catalyst NC-200.

[0075] Example 6

[0076] The difference between this example and example 4 is that the amount of o-phenanthroline is changed to 300 mg, and other conditions are exactly the same, to prepare a highly active gasoline and diesel fraction selective hydrogenation catalyst NC-300.

[0077] Example 7

[0078] The difference between this example and example 4 is that the amount of o-phenanthroline is changed to 400 mg, and other conditions are exactly the same, to prepare a highly active gasoline and diesel fraction selective hydrogenation catalyst NC-400.

[0079] Example 8

[0080] The difference between this example and example 4 is that the amount of o-phenanthroline is changed to 500 mg, and other conditions are exactly the same, to prepare a highly active gasoline and diesel fraction selective hydrogenation catalyst NC-500.

[0081] Comparative Example 1

[0082] This comparative example provides an industrially commonly used hydrodesulfurization catalyst as a comparative catalyst.

[0083] The preparation method of the comparative catalyst comprises the following steps:

[0084] Dissolve 4.74 g of ammonium metatungstate and 2.26 g of nickel nitrate in 20 mL of deionized water to prepare an impregnation solution;

[0085] The impregnation solution was added dropwise into 10 g of an extruded alumina strip having a diameter of 1.5 mm to obtain a catalyst semi-finished product;

[0086] The semi-finished catalyst was left to stand in the air for 12 hours, dried in an oven at 80°C, and then heated at a rate of 10°C / min and calcined at 400°C in an air atmosphere for 4 hours to obtain the comparative catalyst 1.

[0087] Comparative Example 2

[0088] 20g of pseudo-boehmite was placed in a muffle furnace and heated to 600℃ at a rate of 4℃ / min and then maintained for 2h to obtain powdered γ-Al2O3, which was then pressed into tablets at a pressure of 10Mpa and crushed and sieved to obtain a 20-40 mesh γ-Al2O3 carrier;

[0089] Dissolve 0.5g of glucose in 6g of distilled water to prepare a solution, and then immerse an equal volume of the solution on 7.5g of the above-mentioned γ-Al2O3 carrier. After drying, heat the solution to 600°C at a rate of 10°C / min under nitrogen protection, keep it for 2h, then cool it to room temperature, switch the atmosphere to 5% H2 / Ar mixed gas, heat it to 300°C at a rate of 10°C / min, keep it for 2h to reduce the oxygen-containing residues on the surface of the carbon material, and then cool it to room temperature to obtain a composite carbon material carrier.

[0090] Dissolve 3.15g of ammonium metatungstate and 1.28g of nickel nitrate in water to prepare an impregnation solution;

[0091] The impregnation liquid was dropped onto 7.5 g of the composite carbon material carrier, cured at room temperature for 12 h, dried in an oven at 80°C, then heated at a rate of 10°C / min, and calcined at 400°C under nitrogen protection for 4 hours to obtain the comparative catalyst 2.

[0092] Comparative Example 3

[0093] The difference between this comparative example and Example 4 is that the amount of o-phenanthroline is replaced with 50 mg, and other conditions are exactly the same, to prepare a highly active gasoline and diesel fraction selective hydrogenation catalyst NC-50.

[0094] Comparative Example 4

[0095] The difference between this comparative example and Example 4 is that the amount of o-phenanthroline is replaced with 600 mg, and other conditions are exactly the same, to prepare a highly active gasoline and diesel fraction selective hydrogenation catalyst NC-600.

[0096] Test Example 1

[0097] The catalysts prepared in Examples 1-8 and Comparative Examples 1-4 were evaluated for the hydrogenation reaction of dibenzothiophene.

[0098] Before the hydrogenation reaction, a pre-sulfurization treatment is carried out to make the catalyst have a better hydrogenation effect.

[0099] The presulfurization is carried out using a 10mL high temperature and high pressure hydrogenation microreactor, which is a wet in-situ presulfurization, that is, the catalyst is not unloaded after presulfurization, and the hydrogenation reaction continues directly in the reactor. The presulfurization oil is a n-decane solution containing 5wt% CS2, the presulfurization temperature is 300℃, the pressure is 4MPa, and the liquid hourly space velocity is 1.5h 1 , the hydrogen-oil volume ratio is 300, and the evaluation results are as follows Figure 1-3 As shown, the horizontal axis is the temperature during the hydrogenation reaction.

[0100] The test results show that the catalysts prepared in Examples 1-8 all have excellent hydrodesulfurization effects, especially when the reaction temperature reaches 280°C, the hydrodesulfurization rates of Examples 1-8 can reach more than 95.5%; Figure 1 When polyvinyl pyrrolidone with different molecular weights was used for preparation, the obtained catalysts all had good hydrodesulfurization rates, and the hydrodesulfurization rates did not show significant differences. In addition, the catalyst (NC-500) prepared by using o-phenanthroline had a better desulfurization rate than other embodiments under relatively low temperature conditions of 240°C and 260°C; Reference Figure 2 , o-phenanthroline is selected as the nitrogen source material. If the weight ratio of o-phenanthroline to the γ-Al2O3 carrier is selected in the range of (0.1-0.5):7.5 during the preparation process, the hydrodesulfurization rate of the obtained catalyst under high temperature conditions (280°C) can reach more than 96.88%. When the weight ratio is less than 0.1:7.5 or the weight ratio is greater than 0.5:7.5, the desulfurization rate of the obtained catalyst at high temperature (280°C) shows a downward trend. Among them, especially when the weight ratio of o-phenanthroline to the γ-Al2O3 carrier is selected in the range of (0.2-0.4):7.5, the hydrogen desulfurization rate of the catalyst is optimal and can reach more than 98%; in addition, according to Figure 2 It can be seen that when the weight ratio of o-phenanthroline to the γ-Al2O3 carrier is in the range of (0.1-0.6):7.5, the catalytic effect of the prepared catalyst at 240°C is better than that of other weight ratio embodiments and comparative catalysts; when the weight ratio of o-phenanthroline to the γ-Al2O3 carrier is in the range of (0.1-0.5):7.5, the catalytic effect of the prepared catalyst at 260°C is better than that of other weight ratio embodiments and comparative catalysts; among them, especially when the weight ratio of o-phenanthroline to the γ-Al2O3 carrier is in the range of (0.2-0.4):7.5, the prepared catalyst has the best desulfurization effect at relatively low temperatures of 240°C and 260°C.

[0101] Test Example 2

[0102] refer to Figure 3 According to the XRD diffraction patterns, the particle sizes of NiWO4 of the oxidized catalysts prepared in Examples 5-8 and Comparative Example 2 are shown in Table 1:

[0103]

[0104] Test Example 3

[0105] refer to Figure 4 The W4f orbital peak spectrum shows that in the oxidized catalysts prepared in Examples 4-8 and Comparative Examples 1-2, the peak area percentages of W in different chemical states in the total tungsten are shown in Table 2:

[0106]

[0107] Test Example 4

[0108] refer to Figure 5 The Ni2p orbital energy spectrum shows that in the oxidized catalysts prepared in Examples 4-8 and Comparative Examples 1-2, the peak area percentages of Ni in different chemical states in the total nickel are shown in Table 3:

[0109]

[0110]

[0111] According to the data in Table 2 and Table 3, the test results show that, compared with the currently conventionally used catalysts, that is, compared with the comparative catalyst 1, Examples 4-8 can significantly increase the content of NiWO4 in the obtained catalysts while greatly reducing the content of Al2NiO4 and Al2(WO4)3. Compared with the comparative catalyst 2, the catalysts obtained in Examples 5-8 also have a higher NiWO4 content, while the content of Al2NiO4 and Al2(WO4)3 is lower. Therefore, the preparation method of the present invention can reduce the spinel structure content, promote the oxidation state active phase metal to form Ni(Co)W(Mo)O4, an important precursor of highly active Ni(Co)W(Mo)S, and at the same time, due to the anchor point and electronic regulation of N, the dispersion of the precursor is effectively improved, thereby regulating the hydrogenation reaction path.

[0112] Test Example 5

[0113] The reaction rate, biphenyl content in the product and path selection of the catalysts prepared in Examples 4-8 and Comparative Examples 1-2 were tested, and the results are shown in Table 4:

[0114]

[0115] The test results show that the catalysts prepared in Examples 4-8, compared with comparative catalysts 1 and 2, improve the reaction rate, optimize the hydrogenation reaction path, improve the selectivity of the DDS (direct desulfurization) path, increase the biphenyl content in the hydrogenation product, and achieve directional conversion of the reactant molecules, thereby achieving the purpose of rich production of high-value aromatics.

[0116] Test Example 6

[0117] The catalysts prepared in Examples 4-8 and Comparative Examples 1-2 were used to hydrogenate the full-fraction FCC gasoline.

[0118] Before carrying out hydroprocessing, presulfurization treatment was first carried out to make the catalyst have better hydrogenation effect. The presulfurization was carried out using a 10mL high temperature and high pressure hydrogenation micro-reaction device, which was a wet in-situ presulfurization, i.e., wet presulfurization was adopted, and the catalyst was not unloaded after presulfurization, and hydrogenation reaction was continued directly in the reactor. The presulfurized oil was a n-decane solution containing 5wt%CS2, and the presulfurization temperature was 300°C, the pressure was 2MPa, the liquid hourly space velocity was 1.5h1, and the hydrogen-oil volume ratio was 300.

[0119] The hydroprocessing in this example was carried out using a 10mL high temperature and high pressure hydrogenation microreactor. The evaluation feedstock used was full-range FCC gasoline, with a specific gravity (d4 20 ) is 0.7296, the sulfur content is 470ppm, and the research octane number (RON) is 92.0. The raw materials are pumped in by a plunger pump, and the oil samples after the reaction are cooled in the high separator and collected and analyzed in the low separator. The temperature of the hydrotreatment is 240℃, the pressure is 4MPa, the liquid hourly space velocity is 4.0h1, and the hydrogen-oil volume ratio is 300. The catalyst desulfurization rate after hydrotreatment and the product research octane number and aromatic content are shown in Table 5:

[0120]

[0121] The test results show that the catalysts prepared in Examples 4-8 have better desulfurization effect when hydrotreating full-fraction FCC gasoline, and have good octane retention effect, and the catalytic product has a high aromatic content. Therefore, the catalyst prepared in the present invention can be applied in the gasoline field in two aspects: 1. Direct application in the catalysis of gasoline fractions can show excellent desulfurization effect and improve the octane number; 2. Based on the fact that a large amount of high-value aromatics are retained in the catalytic product, the catalytic product can also be used as a raw material for aromatic extraction, which helps to produce more aromatics, thereby promoting the purpose of "reducing oil and increasing chemical production".

[0122] Test Example 7

[0123] The catalysts prepared in Examples 4-8 and Comparative Examples 1-2 were used to hydrotreat the cracked diesel fraction.

[0124] Before carrying out hydroprocessing, presulfurization treatment was first carried out to make the catalyst have better hydrogenation effect. The presulfurization is carried out using a 10mL high temperature and high pressure hydrogenation micro-reaction device, which is a wet in-situ presulfurization, i.e., wet presulfurization is adopted, and after presulfurization, the catalyst is not unloaded and directly continues the hydrogenation reaction in the reactor. The presulfurized oil is a n-decane solution containing 5wt%CS2, and the temperature of the presulfurization is 300°C, the pressure is 4MPa, the liquid hourly space velocity is 1.5h-1, and the hydrogen-to-oil volume ratio is 300.

[0125] The hydroprocessing was carried out using a 10 mL high temperature and high pressure hydrogenation microreactor. The evaluation raw material used was a catalytic cracking diesel fraction, the specific gravity of which (d4 20 ) is 0.9579, and the sulfur content is 4860ppm. The raw materials are pumped in by a plunger pump. The oil sample after the reaction is cooled in the high separator and collected and analyzed in the low separator. The temperature of the hydrotreatment is 360℃, the pressure is 5MPa, and the liquid hourly space velocity is 2.0h -1 , the hydrogen-to-oil volume ratio is 600. The results of the catalyst desulfurization rate and aromatic content after hydrotreatment are shown in Table 6:

[0126]

[0127]

[0128] The test results show that the catalysts prepared in Examples 4-8 have a better desulfurization rate when hydrotreating cracked diesel fractions, and the catalytic products have a high content of monocyclic aromatic hydrocarbons. The subsequent separation of aromatic hydrocarbons as chemical raw materials will help achieve the goal of "reducing oil and increasing chemical production".

[0129] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation methods of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the claims of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing a highly active gasoline and diesel fraction selective hydrogenation catalyst, characterized in that: The method comprises the following steps: depositing active components on a carbon material / γ-Al2O3 composite carrier, drying and calcining to obtain the highly active gasoline and diesel fraction selective hydrogenation catalyst; The active components include metal salts and auxiliary metal salts; the metal salts and auxiliary metal salts exist in the form of metal oxides in the precursor of the high-activity gasoline and diesel fraction selective hydrogenation catalyst, the metal ions of the metal salts are tungsten ions, and the metal ions of the auxiliary metal salts are nickel ions; The preparation method of the carbon material / γ-Al2O3 composite carrier is as follows: Using γ-Al2O3 as a pre-carrier, preparing a nitrogen-containing organic matter into a solution and loading it on the surface of the pre-carrier and then performing a pyrolysis treatment to obtain the carbon material / γ-Al2O3 composite carrier, wherein the nitrogen-containing organic matter is o-phenanthroline, and the ratio of the o-phenanthroline to the pre-carrier is (0.2-0.4):7.5 by weight; The preparation method of the precursor is as follows: the pseudo-boehmite is heated to 400-600°C at a rate of 2-6°C / min and then maintained for 2-4 hours to obtain a powdered γ-Al2O3, the powdered γ-Al2O3 is crushed and sieved to obtain a γ-Al2O3 precursor, and the particle size of the γ-Al2O3 precursor is 20-40 meshes; The particle size of NiWO4 in the high-activity gasoline and diesel fraction selective hydrogenation catalyst is 16-24nm, the proportion of tungsten in different chemical states to the total tungsten is: WO3 18.25-24.87%, NiWO4 55.67-62.42%, Al2(WO4)3 19.20-19.46%, and the proportion of nickel in different chemical states to the total nickel is: Al2NiO4 14.76-17.65%, NiWO4 47.88-54.13%, NiO 28.22-37.36%.

2. The method for preparing a highly active gasoline and diesel fraction selective hydrogenation catalyst according to claim 1, characterized in that: The steps include: S1: dissolving the metal salt and the auxiliary metal salt in a solvent to prepare an impregnation solution; S2: adding the impregnation solution dropwise to the carbon material / γ-Al2O3 composite carrier to obtain a catalyst semi-finished product; S3: leaving the semi-finished catalyst product to stand in the air, drying it, and calcining it at 200-800° C. in an inert gas atmosphere for 2-8 hours to obtain the highly active gasoline and diesel fraction selective hydrogenation catalyst.

3. The method for preparing a highly active gasoline and diesel fraction selective hydrogenation catalyst according to claim 2, characterized in that: In step S2, the amount of the impregnation solution is the same as the saturated adsorption capacity of the carbon material / γ-Al2O3 composite carrier; and / or, in step S3, the catalyst semi-finished product is left to stand for 10-15 hours and the drying temperature is 70-90°C.

4. The method for preparing a highly active gasoline and diesel fraction selective hydrogenation catalyst according to any one of claims 1 to 3, characterized in that: In the precursor of the highly active gasoline and diesel fraction selective hydrogenation catalyst, the content of the metal oxide corresponding to the metal salt is 5-30%, and the content of the co-metal oxide corresponding to the co-metal salt is 2-15%.

5. A highly active gasoline and diesel fraction selective hydrogenation catalyst, characterized in that: The high-activity gasoline and diesel fraction selective hydrogenation catalyst is prepared by the method according to any one of claims 1 to 4.

6. Use of a highly active gasoline and diesel fraction selective hydrogenation catalyst in the hydrogenation treatment of a straight-run gasoline fraction, a straight-run diesel fraction, a coker gasoline fraction, a coker diesel fraction, a catalytic cracking gasoline fraction, a catalytic cracking diesel fraction and a wax oil fraction, characterized in that: The high-activity gasoline and diesel fraction selective hydrogenation catalyst according to claim 5 is used, or the high-activity gasoline and diesel fraction selective hydrogenation catalyst is prepared by the method according to any one of claims 1-4.

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