Method for producing chemical raw materials through fluidized bed hydrocracking of straight-run fractions

Abstract

The invention discloses a method for producing chemical raw materials through fluidized bed hydrocracking of straight-run fractions. The method comprises the following steps: mixing and preheating straight-run wax oil and hydrogen, and then feeding the mixture and a catalyst sprayed from the lower part of a reactor into a fluidized bed reactor for hydrogenation upgrading reaction. The reaction product is subjected to gas-liquid-solid separation, the solid catalyst is recycled, the separated hydrogen is mixed with the raw material, the liquid product enters a fractionation device, the obtained light naphtha fraction can be used as a high-quality ethylene cracking raw material, and the heavy naphtha fraction can be used for producing aromatic hydrocarbons and high-octane gasoline blending components through catalytic reforming. According to the invention, the BMCI value and the branched paraffin content of the cracking product can be greatly reduced; the technological process is simple, operation is flexible, and technological parameters can be flexibly adjusted according to raw material characteristics and production requirements; the catalyst has strong adaptability to raw materials, and is especially suitable for paraffin-based straight-run wax oil; non-ideal components can be efficiently converted, and the raw material utilization rate is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of petroleum processing, and particularly relates to a method for producing chemical raw materials by hydrocracking of straight-run distillate in a fluidized bed. Background Art

[0002] Petroleum is known as the "blood of industry", and its consumption is closely related to the development of social economy. The petrochemical industry is an industry that refines petroleum to obtain various oil products and basic chemical raw materials. In the first half of 2022 alone, the operating income of the petrochemical industry exceeded 8 trillion yuan, accounting for more than 10% of the total operating income of the above-scale industries in the country. Looking at the three major sectors within the petrochemical industry, due to the high price of the crude oil sector, the operating income of the oil and gas sector accounts for less than 10% of the total industry income, but the total profit can reach about 30% of the total industry profit; on the contrary, for the refining sector, its operating income accounts for 30% of the total industry income, but the total profit is only 10% of the total industry profit, meaning it has to put in a lot of effort to make little money; in sharp contrast, for the chemical sector, both the proportion of operating income and total profit are as high as over 58%. The high added value of chemicals is the main reason for the high profit. Promoting the reduction of oil production and the increase of chemical production in refining projects to produce three olefins and three benzenes, especially ethylene, is not only to meet the national demand but also the best choice for transformation and profitability.

[0003] Looking at the raw materials for steam cracking, the suitable raw materials for steam cracking include traditional straight-run naphtha, light diesel, ethane, and hydrocracking tail oil, etc. Therefore, the main current routes for producing ethylene feedstock are: (1) The technical route of hydrocracking diesel to produce chemical raw materials. By introducing a catalyst with suitable activity and selectivity for ring opening, it can ensure the directional conversion of vacuum gas oil fraction to produce high-quality raw materials suitable for ethylene cracking, with a BMCI value of ≯12 and a high paraffin content. (2) The technical route of solvent extraction and de-aromatization of diesel. Through the effect of polar separation, the naphthenes and most of the aromatics in straight-run diesel are reduced, and the paraffin content in the raffinate is increased, achieving a significant reduction in the BMCI value of diesel. This process needs to consider the economic cost and operating cost of the solvent, as well as the selectivity and solubility during the solvent extraction process. (3) The diesel hydrocracking process, which realizes the saturation of aromatics and the ring opening of naphthenes in diesel, ensuring a large retention of components with a low BMCI value. However, due to the differences in raw materials and reaction processes between diesel hydrocracking and diesel hydrocracking, the reaction rate of diesel hydrocracking is slower than that of diesel hydrocracking, and diesel hydrocracking is prone to produce a large amount of gas components.

[0004] The production of ethylene feedstock by hydrocracking of diesel has also been reported. Mainly using flexible catalysts and medium-high oil type catalysts, while ensuring the conversion rate and yield, through the adjustment of catalyst activity, high paraffin content and low aromatic content of the unconverted tail oil are achieved, and the maximum production of low BMCI value ethylene cracking feedstock is ensured by maximizing both density and distillation range. The reaction is mainly driven by carbocations, with more isomerization and aromatization, and insufficient ideal components, so it is not a very high-quality ethylene feedstock.

[0005] The light naphtha produced by the fluidized bed hydrothermal cracking reaction of straight-run fractions is mainly based on the free radical mechanism, with less isomerization and aromatization. After hydrogenation, the olefins are basically saturated, and there are more ideal components, which is a very high-quality ethylene feedstock. The heavy naphtha produced by the fluidized bed hydrothermal cracking of straight-run fractions is rich in isoparaffins and naphthenes. Isoparaffins themselves have a high octane number and can directly improve the quality of gasoline; naphthenes can be efficiently converted into aromatics through reforming.

[0006] CN1955261A discloses a method for hydrocracking of inferior catalytic cracking diesel. In the method of the present invention, the inferior catalytic diesel is mixed with the heavy hydrocracking feedstock, and then hydrocracking is carried out first. The obtained middle distillate oil is subjected to two-stage hydrocracking to obtain high-aromatics potential heavy naphtha and tail oil with a low BMCI value. Since the sulfur, nitrogen and other impurities have been removed from the middle distillate oil obtained in the first stage, the catalyst activity can be fully exerted. Therefore, it can be operated at a higher space velocity and a lower temperature, and even at a lower hydrogen partial pressure, and the economy is improved. Moreover, the lower hydrogen partial pressure helps the middle distillate oil to be converted into heavy naphtha with high aromatics potential, and the lower temperature reduces the further cracking of heavy naphtha, thus greatly increasing the yield of heavy naphtha. This method mainly describes the conversion of catalytic cracking diesel and the processing of middle distillate oil, but does not introduce and describe how to maximize the production of ethylene feedstock from straight-run diesel hydrogenation conversion.

[0007] The patent CN112143521B introduces a hydrogenation method for producing catalytic reforming feedstock using a mixed feedstock rich in aromatic diesel fraction and wax oil fraction. The main features are: adopting a staged cracking strategy, taking into account the conversion rate and product quality, with a low yield of light naphtha and a high yield of heavy naphtha. Through logistics recycling and staged catalyst design, coking and catalyst deactivation are reduced, and the operation cycle is extended. The hydrogenation method and system provided by this method can significantly improve the selectivity of the heavy naphtha fraction under mild conditions, and can maximize the retention of the cyclic structure of the aromatic diesel fraction in the feedstock, obtaining a heavy naphtha fraction with a high aromatic potential content, which is a high-quality feedstock for the catalytic reforming process. However, the raw material adaptability of this method is not strong enough to handle the largest amount of straight-run distillate oil, nor can it take into account the production of ethylene feedstock.

[0008] Patent CN116410781A discloses a method for producing ethylene feedstock by hydrocracking diesel oil. The method is characterized by the following steps: The diesel oil feedstock is mixed with hydrogen, and the hydrocracked mixed stream produced by hydrofining and hydrocracking is subjected to gas-liquid separation, stripping and fractionation to obtain four distillate fractions. The third distillate fraction produced is completely recycled to the feed of the hydrofining or hydrocracking reaction unit for cyclic processing. Compared with the traditional straight-run diesel hydrocracking for producing naphtha, ethylene cracking feedstock and partial jet fuel, the method of this invention has higher ethylene cracking feedstock quality and ethylene yield, but lower ethylene cracking feedstock yield and poor economy.

[0009] Patent CN104611031A introduces a method for hydrocracking waxy oil feedstock. The main feature is that after the conventional waxy oil feedstock is saturated, it enters the furfural refining unit for treatment. The heavy aromatic components are separated and continue for deep saturation ring-opening cracking, and the non-aromatic components enter the aromatic extraction unit. After the heavy aromatic cracking products are mixed with the light aromatics after aromatic extraction, they continue for saturation ring-opening cracking reaction. The reactants enter the aromatic extraction unit. After the light aromatics are separated by the fractionation tower, the heavy components are used as the above-mentioned raw materials mixed with the heavy aromatics, and the light components are discharged from the unit as basic organic raw materials. The non-aromatic components leave the unit and are high-quality steam cracking feedstock for chemical industry. This method extracts aromatics through an aromatic extraction unit before waxy oil cracking, with high cost and energy consumption. Summary of the Invention

[0010] To solve the problem of the relatively high BMCI value in the hydrocracked products of waxy oil in the prior art, the present invention provides a method for hydrocracking straight-run distillate to produce chemical raw materials. The method of the present invention is characterized by adopting a fluidized bed hydrocracking process, which can efficiently achieve the hydrocracking of straight-run distillate oil to produce high-quality ethylene cracking feedstock and catalytic reforming feedstock.

[0011] To achieve the above object of the invention, the present invention provides the following technical solutions:

[0012] A method for producing chemical raw materials by fluidized bed hydrocracking of straight-run waxy oil, comprising the following steps:

[0013] Preheating the feed: The straight-run waxy oil and hydrogen are preheated to a suitable temperature in a heating furnace and then transported to the fluidized bed reactor; at the same time, the catalyst is sprayed into the lower part of the fluidized bed reactor to make the straight-run waxy oil, hydrogen and catalyst fully contact for hydro-upgrading reaction;

[0014] Gas-liquid-solid separation: The hydrogenated product enters the separation device to complete the three-phase separation of gas, liquid and solid;

[0015] Material recycling:

[0016] The solid material separated by the separation device is re-fed into the fluidized bed reactor;

[0017] The separated gas product enters the gas separation unit, where hydrogen is separated out. The separated hydrogen is remixed with the straight-run wax oil and participates in the reaction again;

[0018] The separated liquid product enters the fractionation unit, where fractionation is carried out to obtain diesel fraction, naphtha fraction and wax oil fraction;

[0019] Dry gas collection: The dry gas separated by the gas separation unit is collected and utilized;

[0020] Wax oil recycle hydrogenation: The wax oil fraction distilled from the fractionation unit is mixed with the straight-run wax oil feedstock and re-enters the fluidized bed reactor for hydro-upgrading reaction;

[0021] Product utilization: The naphtha fraction distilled from the fractionation unit is used as the feedstock for ethylene cracking; The diesel fraction is recycled to participate in the hydro-upgrading reaction.

[0022] Preferably, the reaction conditions of the fluidized bed reactor are as follows: the hydrogen partial pressure in the reactor is 4 - 15 MPa, the reaction temperature is 380 - 450 °C, the liquid hourly space velocity is 0.5 - 5 h -1 , and the volume ratio of hydrogen to the mixture is 300 - 1200 Nm 3 / m 3 .

[0023] Preferably, the catalyst includes a carrier and an active metal component supported on the carrier. Among them, the carrier is γ-Al2O3, and the active metal component includes Group VI metal elements and Group II metal elements; Based on the total weight of the catalyst, the content of alumina is 70 - 95 wt%, and the content of metal elements calculated as oxides is 5 - 30 wt%.

[0024] Preferably, the preparation method of the catalyst is as follows:

[0025] Molybdenum salt impregnation: The molybdenum source is configured into an aqueous solution with a certain concentration. After constant volume, it is impregnated onto γ-Al2O3 by the equal-volume impregnation method, so that molybdenum elements are uniformly loaded on the surface of γ-Al2O3;

[0026] Zinc salt impregnation: The zinc source is configured into an aqueous solution with a certain concentration. After constant volume, it is impregnated onto the γ-Al2O3 that has already been loaded with molybdenum elements by the equal-volume impregnation method, so that zinc elements and molybdenum elements are co-loaded on γ-Al2O3;

[0027] Drying and calcination: The obtained γ-Al2O3 above is placed in a drying oven at 120 °C for 8 hours to fully remove moisture, and then placed in a muffle furnace at 500 °C for 3 hours to convert the metal salt into an oxide, obtaining an oxidized catalyst.

[0028] Preferably, ammonium molybdate is selected as the molybdenum source, and zinc nitrate is selected as the zinc source.

[0029] Preferably, the catalyst needs to be pre-sulfurized before being fed into the fluidized bed reactor. The pre-sulfurization operating conditions are as follows: the temperature is 250 - 340 °C, the time is 1 - 5 h, and the pressure is 2 - 8 MPa.

[0030] Preferably, the pre-sulfurization medium is a reducing gas containing H2S, where the volume fraction of H2S is 0.1 - 10%; or it is a mixture of hydrocarbon oil that can provide H2S and hydrogen.

[0031] Preferably, the straight-run wax oil is paraffin-based straight-run wax oil, and the sulfur content of this paraffin-based straight-run wax oil is not higher than 1.5 wt%, the nitrogen content is not higher than 0.1 wt%, and the heavy metal content is not higher than 10 ppm.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] (1) In the present invention, a fluidized bed is used as the hydro-upgrading reactor, which can effectively cause a significant decrease in the BMCI value of the cracked products of straight-run wax oil and a remarkable reduction in the content of branched alkanes. This characteristic makes the generated products excellent in quality. Among them, the light naphtha fraction is rich in normal alkanes and becomes a high-quality ethylene cracking raw material; the heavy naphtha fraction, due to its high content of naphthenes and isoparaffins, can be used as a catalytic reforming raw material for producing aromatics and high-octane gasoline blending components, greatly enhancing the application value of the products.

[0034] (2) The process design of the present invention is simple and clear, eliminating complex and cumbersome steps. During the actual operation, various process parameters such as reaction temperature, pressure, and space velocity can be flexibly adjusted according to different raw material characteristics and production requirements, so as to achieve precise control of the production process and better adapt to diverse industrial production scenarios.

[0035] (3) During the fluidized bed hydro-upgrading process, it can efficiently promote the conversion of non-ideal components in straight-run wax oil into more economically valuable products, effectively improving the utilization rate of raw materials and reducing resource waste.

[0036] (4) By adopting the fluidized bed hydro-upgrading process, the deactivation of the catalyst is effectively reduced, the coking risk inside the equipment is lowered, and thus the continuous operation cycle of the fluidized bed hydro-upgrading device is significantly extended. Description of the Drawings

[0037] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0038] Figure 1 This is the process flow diagram of the straight-run wax oil hydro-upgrading process of the present invention.

[0039] Wherein: 1. Hydrogen; 2. Straight-run wax oil; 3. Catalyst; 4. Heating furnace; 5. Mixture before reaction; 6. Fluidized bed reactor; 7. Hydro-upgrading reaction product; 8. Separation device; 9. Gas product; 10. Gas separation unit; 11. Precipitation; 12. Liquid product; 13. Fractionating tower; 14. Light naphtha fraction; 15. Heavy naphtha fraction; 16. Diesel fraction; 17. Wax oil fraction. Specific embodiments

[0040] The following will describe the embodiments of the present invention in detail with reference to the drawings. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other; and, based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present disclosure.

[0041] The following describes various aspects of the embodiments within the scope of the appended claims. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on the present disclosure, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functionality in addition to one or more of the aspects described herein.

[0042] Embodiment 1

[0043] Hydrocracking of straight-run wax oil:

[0044] 1. Raw materials

[0045] Paraffin-based straight-run wax oil is used as the raw material, and its main properties are as follows: density 910.01 g / cm 3 , sulfur content 4527 mg / kg, nitrogen content 437 mg / kg, heavy metal content (calculated as nickel, vanadium, etc.) not higher than 10 ppm.

[0046] 2. Catalyst Preparation

[0047] The preparation method of the straight-run vacuum gas oil hydro-upgrading catalyst is as follows: Weigh 400 g of alumina microspheres and calcine them in a muffle furnace at 500 °C for 1 hour. Take 41.4 g of ammonium molybdate tetrahydrate and make up the volume to 177.2 ml with pure water, then impregnate it onto 20 g of the calcined alumina. Take 80.853 g of zinc nitrate hexahydrate and make up the volume to 177.2 ml with pure water, then impregnate it onto 200 g of the calcined alumina. After drying at 120 °C for 8 hours and calcining at 500 °C for 3 hours, the oxidized catalyst is obtained.

[0048] Catalyst Presulfidation

[0049] Perform presulfidation treatment on 200 g of the prepared catalyst. The presulfidation medium is a reducing gas containing 5% by volume of H2S. Presulfide at a temperature of 300 °C and a pressure of 5 MPa for 3 hours.

[0050] Hydrocracking Reaction

[0051] Preheat straight-run vacuum gas oil 2 and hydrogen 1 to 380 °C in a heating furnace 4, and then inject them into a fluidized bed reactor 6. The hydrogen partial pressure in the reactor is 6 MPa, the reaction temperature is 430 °C, and the liquid hourly space velocity is 1 h - 1. The volume ratio of hydrogen 1 to the mixture 5 before the reaction is 500 Nm 3 / m 3 . At the same time, inject the presulfided catalyst 3 into the lower part of the fluidized bed reactor 6 through a feed pump.

[0052] Product Separation and Analysis

[0053] The hydro-upgrading reaction product 7 enters a separation device 8 for gas-liquid-solid separation. Among the separated precipitate 11, the solid catalyst 3 is recycled. The gas product 9 is separated by a gas separation unit 10 to recycle hydrogen 1, and the liquid product 12 enters a fractionating tower 13 for fractionation. The light naphtha fraction 14 fractionated enters an ethylene cracking unit, the heavy naphtha fraction 15 fractionated enters a catalytic reforming unit, and the diesel fraction 16 and the wax oil fraction 17 are re-entered into the fluidized bed reactor 6 for hydro-upgrading together with the raw material.

[0054] Table 1 - Main Properties of Industrial Straight-Run Vacuum Gas Oil

[0055]

[0056]

[0057] Table 2 - Fluidized Bed Hydrocracking Results of Industrial Straight-Run Vacuum Gas Oil

[0058] <![CDATA[Density (20 °C) / (g / cm 3 )]]> <![CDATA[833.00kg / m 3 > Distillation range / °C / IBP / 10% 37.71 / 106.40 30 / 50％ 192.05 / 276.86 70 / 90％ 356.71 / 547.68 95% / EBP 574.79 / 635.00 Yield of light naphtha 26.17％ Yield of heavy naphtha 14.35％ Yield of diesel oil 35.88％

[0059] As can be seen from Table 2, the yield of light naphtha in the product is 26.17%, the yield of heavy naphtha is 14.35%, and the yield of diesel is 35.88%. The hydro-upgrading effect of fluidized bed is obvious.

[0060] Table 3 - Group composition of light naphtha (70 - 140°C) fraction in the fluidized bed hydrocracking product of industrial straight-run wax oil

[0061]

[0062] As can be seen from Table 3, in the light naphtha fraction of the fluidized bed hydrocracking product of straight-run wax oil, the yield of normal paraffins is 37.08%, which is a high-quality raw material for ethylene cracking.

[0063] Example 2

[0064] Hydrocracking of straight-run diesel

[0065] Raw material

[0066] Straight-run diesel is selected as the raw material, and its properties are: density 839.81 g / cm 3 , sulfur content 2607 mg / kg, nitrogen content 152 mg / kg.

[0067] Catalyst and reaction conditions

[0068] The same catalyst preparation method and presulfurization treatment as in Example 1 are adopted. The hydrocracking reaction conditions are: hydrogen partial pressure 6 MPa, reaction temperature 430°C, liquid hourly space velocity 1.0 h - -1, volume of hydrogen to mixture 500 Nm 3 / m 3 .

[0069] Product situation

[0070] Table 4 - Main properties of industrial straight-run diesel

[0071] Name of feedstock Industrial straight-run diesel oil <![CDATA[Density (20 °C) / (g / cm 3 )]]> <![CDATA[839.81g / cm 3 > Distillation range / °C / IBP / 10% 228.6 / 263.71 30 / 50％ 289.03 / 308.02 70 / 90％ 328.79 / 359.06 95% / EBP 376.41 / 386.57

[0072] Table 5 - Hydro-upgrading results of industrial straight-run diesel

[0073] <![CDATA[Density (20 °C) / (g / cm 3 )]]> <![CDATA[778.30kg / m 3 > Distillation range / °C / IBP / 10% 80.86 / 118.80 30 / 50％ 174.24 / 226.91 70 / 90％ 265.48 / 313.36 95% / EBP 335.11 / 354.48 Yield of light naphtha 16.32％ Yield of heavy naphtha 20.02％

[0074] Table 6 - Group composition of industrial straight-run diesel

[0075]

[0076]

[0077] Table 7 - Analysis report on the group composition of light naphtha fraction (70 - 140°C) of the product

[0078]

[0079] Table 8 - Analysis Report on the Group Composition of the Product Heavy Naphtha Fraction (140 - 200 °C)

[0080]

[0081] As can be seen from the results of Table 7 and Table 8, after fluidized bed hydro-upgrading, the yield of light naphtha can reach 16.02%, and the yield of heavy naphtha can reach 20.02%. Among the light naphtha fractions, the content of normal paraffins is as high as 45.62%, and the olefin content is less than 1%, which can be used as high-quality ethylene cracking raw materials. In the heavy naphtha fraction, the potential aromatic content is 22.77%, and the naphthene content is 16.59%. Aromatics and high-octane gasoline blending components can be produced through aromatics extraction, catalytic reforming, etc.

[0082] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for producing chemical raw materials by straight-run distillate fluidized bed hydrocracking, characterized in that, The steps are as follows: Preheat the feed: Preheat straight-run wax oil and hydrogen to an appropriate temperature in a heating furnace and then transport them to a fluidized bed reactor. At the same time, spray the catalyst into the lower part of the fluidized bed reactor to make the straight-run wax oil, hydrogen and catalyst fully contact and carry out hydro-upgrading reaction; Gas-liquid-solid separation: The hydrogenated product enters a separation device to complete the three-phase separation of gas, liquid and solid; Material recycling: The solid material separated by the separation device is re-fed into the fluidized bed reactor; The separated gas product enters a gas separation unit to separate the hydrogen therein. The separated hydrogen is remixed with the straight-run wax oil and participates in the reaction again; The separated liquid product enters a fractionation device and is fractionated in the fractionation device to obtain diesel fraction, naphtha fraction and wax oil fraction; Dry gas collection: The dry gas separated by the gas separation unit is collected and utilized; Wax oil recycle hydrogenation: The wax oil fraction distilled from the fractionation device is mixed with the straight-run wax oil raw material and re-enters the fluidized bed reactor for hydro-upgrading reaction; Product utilization: The naphtha fraction distilled from the fractionation device is used as the feedstock for ethylene cracking. The diesel fraction circulates to participate in the hydro-upgrading reaction.

2. A method for producing chemical raw materials by straight-run distillate fluidized bed hydrocracking according to claim 1, characterized in that, The reaction conditions of the fluidized bed reactor are as follows: the hydrogen partial pressure in the reactor is 4 - 15 MPa, the reaction temperature is 380 - 450 °C, the liquid hourly space velocity is 0.5 - 5 h -1 , and the volume ratio of hydrogen to the mixture is 300 - 1200 Nm 3 / m 3 .

3. A method for producing chemical raw materials by straight-run distillate fluidized bed hydrocracking according to claim 1, characterized in that, The catalyst includes a carrier and an active metal component supported on the carrier. Among them, the carrier is γ-Al2O3, and the active metal component includes Group VI metal elements and Group II metal elements; based on the total weight of the catalyst, the content of alumina is 70-95% by weight, and the content of metal elements calculated as oxides is 5-30% by weight.

4. A method for producing chemical raw materials by straight-run distillate fluidized bed hydrocracking according to claim 3, characterized in that The preparation method of the catalyst is as follows: Molybdenum salt impregnation: Configure a molybdenum source into an aqueous solution with a certain concentration. After constant volume, impregnate it onto γ-Al2O3 by the equal-volume impregnation method to make the molybdenum element evenly supported on the surface of γ-Al2O3; Zinc salt impregnation: Configure a zinc source into an aqueous solution with a certain concentration. After constant volume, impregnate it onto γ-Al2O3 that has been loaded with molybdenum element by the equal-volume impregnation method to make the zinc element and molybdenum element jointly supported on γ-Al2O3; Drying and calcination: Place the obtained γ-Al2O3 in a drying oven at 120°C for 8 hours to fully remove moisture, and then place it in a muffle furnace at 500°C for 3 hours to convert the metal salt into an oxide to obtain an oxidized catalyst.

5. A method for producing chemical raw materials by straight-run distillate fluidized bed hydrocracking according to claim 4, characterized in that, The molybdenum source is selected as ammonium molybdate, and the zinc source is selected as zinc nitrate.

6. A method for producing chemical raw materials by straight-run distillate fluidized bed hydrocracking according to claim 5, characterized in that, The catalyst also needs to be pre-sulfurized before being fed into the fluidized bed reactor. The pre-sulfurization operating conditions are: temperature is 250-340°C, time is 1-5h, and pressure is 2-8MPa.

7. A method for producing chemical raw materials by straight-run distillate fluidized bed hydrocracking according to claim 6, characterized in that, The pre-sulfurization medium is a reducing gas containing H2S, where the volume fraction of H2S is 0.1-10%; or it is a mixture of hydrocarbon oil that can provide H2S and hydrogen.

8. A method for producing chemical raw materials by straight-run distillate fluidized bed hydrocracking according to claim 1, characterized in that The straight-run wax oil is paraffin-based straight-run wax oil, and the sulfur content of the paraffin-based straight-run wax oil is not higher than 1.5 wt%, the nitrogen content is not higher than 0.1 wt%, and the heavy metal content is not higher than 10 ppm.

Images