A method for catalytic hydrogenation refining of coking crude benzene

Abstract

The present invention discloses a method for catalytic hydrogenation refining of coking crude benzene, which belongs to the technical field of crude benzene hydrogenation refining, and comprises the following steps: preparing a catalyst carrier; preparing a catalyst impregnation liquid; preparing a catalytic hydrogenation catalyst; catalytic hydrogenation refining; and component separation. The present invention adopts high-temperature co-carbonization technology to combine rectorite with pollen to form a modified carbonized pollen with a multi-level pore structure, which significantly enhances the adsorption, thermal stability and catalytic performance. The hollow structure catalyst nanoparticles prepared by the Kirkendall effect not only increase the active sites, but also promote the internal diffusion of reactants and products, effectively improving the catalytic efficiency. At the same time, the chelation effect of the ionic liquid and the synergistic effect of the oxygen-containing functional group realize the effective loading of the catalyst carrier and the catalyst body, enhance the stability and service life of the catalyst, strengthen its catalytic and desulfurization performance, and provide a new way to achieve efficient and environmentally friendly chemical production.

Description

Technical Field

[0001] The invention belongs to the technical field of crude benzene hydrogenation refining, and in particular relates to a method for catalytic hydrogenation refining of coking crude benzene. Background Art

[0002] Benzene is a basic chemical raw material widely used in industries such as pharmaceuticals, plastics, rubber, dyes, spices and pesticides. It is mainly produced through processes such as coal distillation, catalytic cracking and catalytic reforming of petroleum. However, the benzene obtained by these processes usually contains a variety of impurities, including unsaturated hydrocarbons, sulfur-containing and nitrogen-containing compounds, and the presence of these impurities seriously affects the quality and application range of benzene. Unsaturated hydrocarbons, such as olefins and alkynes, can cause side reactions in subsequent chemical reactions, affecting the selectivity and yield of the products. Sulfur-containing compounds, such as mercaptans, sulfides, thiophenes and their derivatives, are not only harmful to the environment, but also cause catalyst poisoning in some applications. Nitrogen-containing compounds, such as pyridine and its derivatives, also have a negative impact on catalysts and reduce reaction efficiency. In order to improve the purity and application value of benzene, crude benzene must be refined to remove these impurities. Traditional refining methods include physical methods such as fractionation, adsorption and solvent extraction, and chemical methods such as hydrogenation, oxidation and chlorination. However, these methods often have problems such as low efficiency, high cost, complex operation or environmental pollution.

[0003] Hydrofining is an effective chemical method that converts sulfur- and nitrogen-containing impurities into sulfides and ammonia under the action of a catalyst, while hydrogenating unsaturated hydrocarbons into saturated hydrocarbons. This method has the advantages of mild reaction conditions, high conversion rate, low energy consumption and environmental friendliness. However, the traditional hydrogenation catalyst has insufficient pore structure, low activity, low catalytic efficiency, low desulfurization efficiency and poor stability, which limits its application in industry. Summary of the invention

[0004] In view of the above situation, in order to overcome the defects of the prior art, the present invention has developed a method for catalytic hydrogenation refining of coking crude benzene. By preparing a catalyst carrier and a catalyst impregnation liquid with a special structure and composition, and an optimized catalytic hydrogenation process, the hydrogenation refining and desulfurization of coking crude benzene are achieved, and the purity and application value of benzene are improved.

[0005] In order to achieve the above object, the following technical scheme is adopted: The present invention provides a method for catalytic hydrogenation refining of coking crude benzene, comprising the following steps:

[0006] S1. Preparation of catalyst carrier: treating pollen with ultrasonic treatment of deionized water for 1-2h, adding it to a mixed solution of anhydrous ethanol and formaldehyde in a volume ratio of 1:1, stirring for 1-2h, filtering, washing with deionized water, and then mixing with rectorite powder, putting them together in a tube furnace, heating to 300-400°C and calcining for 1-2h under nitrogen at a flow rate of 150-200mL / min to obtain rectorite-modified carbonized pollen, adding the rectorite-modified carbonized pollen to a high-pressure hydrothermal reactor lined with polytetrafluoroethylene, adding hexamethylenediamine, 1,2-dibromopropane and acetonitrile, stirring for 20-50min, washing with deionized water after the reaction, and drying at 80°C for 8-12h to obtain the catalyst carrier;

[0007] S2, preparing a catalyst impregnation solution: mixing molybdenum powder, cobalt powder and nickel powder with a phosphorus source under a nitrogen atmosphere, heating to 300-350° C. to form a phosphide, then dispersing the obtained phosphide in oleylamine at a high speed, heating to 250° C. under nitrogen protection, maintaining for 10-50 min, and then introducing a mixed gas of oxygen and nitrogen to form a metal oxide with a hollow structure, that is, obtaining the catalyst impregnation solution;

[0008] S3, preparing a catalytic hydrogenation catalyst: immersing the catalyst carrier in a catalyst impregnation solution for 5-8 hours, drying at 80° C. for 3-5 hours, and then further drying at 110° C. for 5-8 hours to obtain the catalytic hydrogenation catalyst;

[0009] S4, catalytic hydrogenation refining: the prepared catalytic hydrogenation catalyst is filled into the pre-reactor and the main reactor of the two-stage reactor, the coking crude benzene first passes through the heavy component removal tower, and then enters the pre-reactor under the pressure and speed increase of the pressure pump, and the product of the pre-reactor is passed into the main reactor for further catalytic hydrogenation;

[0010] S5. Component separation: After the reaction products of the main reactor are cooled to room temperature, they are separated by a three-phase separator, and the liquid components are sent to a stabilization tower, where acidic gases containing hydrogen sulfide and ammonia are removed. High-purity pure benzene, pure toluene and xylene are then obtained through fractionation.

[0011] Furthermore, the mass ratio of the pollen, rectorite powder, hexamethylenediamine, 1,2-dibromopropane and acetonitrile is 10-30:15-40:5-8:8-15:50-80.

[0012] Furthermore, the mass ratio of the molybdenum powder, cobalt powder, nickel powder, phosphorus source and oleylamine is 5-10:1-3:1-3:10-20:50-80.

[0013] Furthermore, the phosphorus source is one of red phosphorus, white phosphorus and trioctylphosphine.

[0014] Furthermore, the flow rate of the mixed gas of oxygen and nitrogen is 150-200 mL / min, and the flow ratio of oxygen to nitrogen is 2:1.

[0015] Furthermore, the temperature of the pre-reactor is 180-240° C., and the pressure is 3.5-5 MPa.

[0016] Furthermore, the temperature of the main reactor is 320-370°C, and the pressure is 3.5-5MPa.

[0017] Furthermore, the temperature of the heavy component removal tower is 100-200°C.

[0018] Furthermore, the flow rate of the coking crude benzene entering the pre-reactor is 0.5-2 m / s.

[0019] Furthermore, the temperature of the stabilization tower is 50-100°C.

[0020] The beneficial effects of the present invention are:

[0021] (1) The present invention adopts a high-temperature co-carbonization method to combine rectorite and pollen. The rectorite is structurally amorphous at high temperature to perform inorganic pillar modification on carbonized pollen, thereby increasing the interlayer spacing of carbonized pollen. The rectorite and carbonized pollen have different pore sizes, so that the modified carbonized pollen has a multi-level pore structure and the surface of the carbonized pollen has abundant oxygen-containing functional groups, thereby improving its adsorption capacity, thermal stability and catalytic performance. Then, mesopores are introduced between the carbonized pollen layers through the example liquid formed by hexamethylenediamine and 1,2-dibromopropane, thereby further enriching the pore structure and providing more active sites.

[0022] (2) The present invention diffuses phosphorus into metal powder under nitrogen protection to form phosphide. Based on the Kirkendall effect, the diffusion rate of phosphorus is faster than that of metal atoms. Phosphorus is enriched inside the particles, and metal atoms are pushed to the surface of the particles to form solid phosphide particles. During the oxidation process, since the oxidation mainly occurs on the surface, the internal phosphorus begins to move to the surface by diffusion to supplement the phosphorus replaced by oxygen atoms. Vacancies begin to form inside the particles, and the vacancies gradually accumulate and merge to form larger holes, which eventually lead to the formation of a hollow structure inside the particles, thereby obtaining catalyst nanoparticles with a hollow structure.

[0023] (3) The central control structure of the catalyst nanoparticles prepared by the present invention provides a larger internal surface area, increases the number of active sites, and allows reactants and products to diffuse more freely inside the catalyst, reducing diffusion restrictions and improving reaction rate and catalytic efficiency;

[0024] (4) The present invention realizes the effective loading of the catalyst carrier on the catalyst body through the chelating effect of the ionic liquid and the oxygen-containing functional groups introduced by the rectorite, which not only improves the stability and service life of the catalyst, but also enhances its catalytic and desulfurization capabilities, and helps to achieve a cleaner chemical production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention is a process flow chart of a method for catalytic hydrogenation refining of coking crude benzene;

[0026] Figure 2 The yield of liquid products in each embodiment and comparative example of the method for catalytic hydrogenation refining of coking crude benzene of the present invention;

[0027] Figure 3 It is the BTX retention rate of each embodiment and comparative example of the method for catalytic hydrogenation refining of coking crude benzene of the present invention;

[0028] Figure 4 The thiophene content in the refined products of various embodiments and comparative examples of the method for catalytic hydrogenation refining of coking crude benzene of the present invention is shown.

[0029] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

[0032] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are purchased from commercial channels unless otherwise specified. The pollen is rapeseed pollen purchased from Xi'an Lavia Biotechnology Co., Ltd., and the SCST-313 nickel-molybdenum hydrogenation catalyst is purchased from Sichuan Shutai Chemical Technology Co., Ltd. Example 1

[0033] A method for catalytic hydrogenation refining of coking crude benzene

[0034] The method comprises the following steps:

[0035] S1. Preparation of catalyst carrier: treating pollen with ultrasonic treatment of deionized water for 1 hour, adding it to a mixed solution of anhydrous ethanol and formaldehyde in a volume ratio of 1:1, stirring for 1 hour, filtering, washing with deionized water, and then mixing with rectorite powder, putting them together in a tube furnace, heating to 300°C and calcining for 1 hour under a nitrogen flow rate of 150 mL / min to obtain rectorite-modified carbonized pollen, adding the rectorite-modified carbonized pollen to a high-pressure hydrothermal reactor lined with polytetrafluoroethylene, and then adding hexamethylenediamine, 1,2-dibromopropane and acetonitrile, stirring for 20 minutes, washing with deionized water after the reaction, and drying at 80°C for 8 hours to obtain the catalyst carrier;

[0036] S2, preparing a catalyst impregnation solution: mixing molybdenum powder, cobalt powder and nickel powder with red phosphorus under a nitrogen atmosphere, heating to 300° C. to form a phosphide, then dispersing the obtained phosphide in oleylamine at a high speed, heating to 250° C. under nitrogen protection, maintaining for 10 min, and then introducing a mixed gas of oxygen and nitrogen at a flow rate of 150 mL / min and a flow ratio of oxygen to nitrogen of 2:1 to form a metal oxide with a hollow structure, that is, obtaining the catalyst impregnation solution;

[0037] S3, preparing a catalytic hydrogenation catalyst: immersing the catalyst support in a catalyst impregnation solution for 5 hours, drying at 80° C. for 3 hours, and then drying at 110° C. for 5 hours to obtain the catalytic hydrogenation catalyst;

[0038] S4, catalytic hydrogenation refining: the prepared catalytic hydrogenation catalyst is filled into the pre-reactor and the main reactor of the two-stage reactor, the coking crude benzene is first passed through the heavy component removal tower, the temperature of the heavy component removal tower is 100°C, and then the pressure pump is used to increase the pressure and speed to adjust the flow rate to 0.5m / s to enter the pre-reactor, the temperature of the pre-reactor is 180°C, the pressure is 3.5MPa, the product of the pre-reactor is passed into the main reactor for further catalytic hydrogenation, the temperature of the main reactor is 320°C, and the pressure is 3.5MPa;

[0039] S5. Component separation: After the reaction product of the main reactor drops to room temperature, it is separated by a three-phase separator, and the liquid component is sent to a stabilization tower. The temperature of the stabilization tower is 50°C. Acidic gases containing hydrogen sulfide and ammonia are removed in the stabilization tower, and then high-purity pure benzene, pure toluene and xylene are obtained through fractionation.

[0040] The mass ratio of the pollen, rectorite powder, hexamethylenediamine, 1,2-dibromopropane and acetonitrile is 10:15:5:8:50.

[0041] The mass ratio of the molybdenum powder, cobalt powder, nickel powder, red phosphorus and oleylamine is 5:1:1:10:50. Example 2

[0042] A method for catalytic hydrogenation refining of coking crude benzene

[0043] The method comprises the following steps:

[0044] S1. Preparation of catalyst carrier: treating pollen with ultrasonic treatment of deionized water for 2 h, adding it to a mixed solution of anhydrous ethanol and formaldehyde in a volume ratio of 1:1, stirring for 2 h, filtering, washing with deionized water, and then mixing with rectorite powder, putting them together in a tube furnace, heating to 400°C and calcining for 2 h under a nitrogen flow rate of 200 mL / min to obtain rectorite-modified carbonized pollen, adding the rectorite-modified carbonized pollen to a high-pressure hydrothermal reactor lined with polytetrafluoroethylene, and then adding hexamethylenediamine, 1,2-dibromopropane and acetonitrile, stirring for 50 min, washing with deionized water after the reaction, and drying at 80°C for 12 h to obtain the catalyst carrier;

[0045] S2, preparing a catalyst impregnation solution: mixing molybdenum powder, cobalt powder and nickel powder with white phosphorus under a nitrogen atmosphere, heating to 350° C. to form a phosphide, then dispersing the obtained phosphide in oleylamine at a high speed, heating to 250° C. under nitrogen protection, maintaining for 50 min, and then introducing a mixed gas of oxygen and nitrogen at a flow rate of 200 mL / min and a flow ratio of oxygen to nitrogen of 2:1 to form a metal oxide with a hollow structure, that is, obtaining the catalyst impregnation solution;

[0046] S3, preparing a catalytic hydrogenation catalyst: immersing the catalyst carrier in a catalyst impregnation solution for 8 hours, drying at 80° C. for 5 hours, and then further drying at 110° C. for 8 hours to obtain the catalytic hydrogenation catalyst;

[0047] S4, catalytic hydrogenation refining: the prepared catalytic hydrogenation catalyst is filled into the pre-reactor and the main reactor of the two-stage reactor, the coking crude benzene is first passed through the heavy component removal tower, the temperature of the heavy component removal tower is 200°C, and then the pressure pump is used to increase the pressure and speed to adjust the flow rate to 2m / s to enter the pre-reactor, the temperature of the pre-reactor is 240°C, the pressure is 5MPa, the product of the pre-reactor is passed into the main reactor for further catalytic hydrogenation, the temperature of the main reactor is 370°C, and the pressure is 5MPa;

[0048] S5. Component separation: After the reaction products of the main reactor are cooled to room temperature, they are separated by a three-phase separator, and the liquid components are sent to a stabilization tower. The temperature of the stabilization tower is 100°C. Acidic gases containing hydrogen sulfide and ammonia are removed in the stabilization tower, and then high-purity pure benzene, pure toluene and xylene are obtained through fractionation.

[0049] The mass ratio of the pollen, rectorite powder, hexamethylenediamine, 1,2-dibromopropane and acetonitrile is 30:40:8:15:80.

[0050] The mass ratio of the molybdenum powder, cobalt powder, nickel powder, white phosphorus and oleylamine is 10:3:3:20:80. Example 3

[0051] A method for catalytic hydrogenation refining of coking crude benzene

[0052] The method comprises the following steps:

[0053] S1. Preparation of catalyst carrier: treating pollen with ultrasonic treatment of deionized water for 1.5 h, adding it to a mixed solution of anhydrous ethanol and formaldehyde in a volume ratio of 1:1, stirring for 1.5 h, filtering, washing with deionized water, and then mixing with rectorite powder, putting them together in a tube furnace, heating to 350° C. and calcining for 1.5 h under a nitrogen flow rate of 180 mL / min to obtain rectorite-modified carbonized pollen, adding the rectorite-modified carbonized pollen to a high-pressure hydrothermal reactor lined with polytetrafluoroethylene, and then adding hexamethylenediamine, 1,2-dibromopropane and acetonitrile, stirring for 40 min, washing with deionized water after the reaction, and drying at 80° C. for 10 h to obtain the catalyst carrier;

[0054] S2, preparing a catalyst impregnation solution: mixing molybdenum powder, cobalt powder and nickel powder with trioctylphosphine under a nitrogen atmosphere, heating to 320° C. to form a phosphide, and then dispersing the obtained phosphide in oleylamine at a high speed, heating to 250° C. under nitrogen protection, maintaining for 30 min, and then introducing a mixed gas of oxygen and nitrogen at a flow rate of 170 mL / min and a flow ratio of oxygen to nitrogen of 2:1 to form a metal oxide with a hollow structure, that is, obtaining the catalyst impregnation solution;

[0055] S3, preparing a catalytic hydrogenation catalyst: immersing the catalyst carrier in a catalyst impregnation solution for 6 hours, drying at 80° C. for 4 hours, and then drying at 110° C. for 6 hours to obtain the catalytic hydrogenation catalyst;

[0056] S4, catalytic hydrogenation refining: the prepared catalytic hydrogenation catalyst is filled into the pre-reactor and the main reactor of the two-stage reactor, the coking crude benzene is first passed through the heavy component removal tower, the temperature of the heavy component removal tower is 180°C, and then the pressure pump is used to increase the pressure and speed to adjust the flow rate to 1m / s to enter the pre-reactor, the temperature of the pre-reactor is 200°C, and the pressure is 4MPa. The product of the pre-reactor is passed into the main reactor for further catalytic hydrogenation, and the temperature of the main reactor is 350°C and the pressure is 4MPa;

[0057] S5. Component separation: After the reaction product of the main reactor drops to room temperature, it is separated by a three-phase separator, and the liquid component is sent to a stabilization tower. The temperature of the stabilization tower is 80°C. Acidic gases containing hydrogen sulfide and ammonia are removed in the stabilization tower, and then high-purity pure benzene, pure toluene and xylene are obtained through fractionation.

[0058] The mass ratio of the pollen, rectorite powder, hexamethylenediamine, 1,2-dibromopropane and acetonitrile is 20:30:6:10:60.

[0059] The mass ratio of the molybdenum powder, cobalt powder, nickel powder, trioctylphosphine and oleylamine is 6:2:2:18:60.

[0060] Comparative Example 1

[0061] The difference between this comparative example and Example 3 is that hexamethylenediamine and 1,2-dibromopropane are not added in the preparation of the catalyst carrier, and the remaining components, component contents, and preparation process are the same as those in Example 3.

[0062] Comparative Example 2

[0063] The difference between this comparative example and Example 3 is that no rectorite powder is added when preparing the catalyst carrier, but the pollen is directly carbonized. The other components, component contents, and preparation process are the same as those in Example 3.

[0064] Comparative Example 3

[0065] The difference between this comparative example and Example 3 is that the catalyst impregnation solution includes the following components in parts by weight: 6 parts of molybdenum phosphide, 2 parts of cobalt phosphide, 2 parts of nickel phosphide and 60 parts of oleylamine, and the remaining components, component contents and preparation process are the same as those in Example 3.

[0066] Comparative Example 3

[0067] The difference between this comparative example and Example 3 is that a commercially available SCST-313 nickel-molybdenum hydrogenation catalyst is used as a catalytic hydrogenation catalyst for catalytic hydrogenation refining.

[0068] Results Analysis

[0069] The catalytic efficiency of the catalytic hydrorefining method of the present invention was evaluated by the liquid product yield and the BTX retention rate.

[0070] Liquid product yield (%) = liquid product mass / feed material mass × 100%, the result is shown in Figure 2 .

[0071] The content of benzene and benzene derivatives was measured by gas chromatography, and then the BTX retention rate was calculated. The results are shown in Figure 3 .

[0072] BTX retention rate (%) = BTX mass in product / BTX mass in raw material × 100%, BTX includes benzene, toluene and xylene.

[0073] The specific conditions of gas chromatography analysis are as follows: use a GC-2020 Shimadzu gas chromatograph, the capillary column model is HP-5MS (30m×0.25mm), 99.999% high-purity nitrogen is used as the carrier gas, the gas chromatograph injector is set to 220℃, the detector temperature is set to 250℃, the initial temperature is 40℃, maintained for 4min, increased to 100℃ at 5℃ / min, and then increased to 220℃ at 20℃ / min.

[0074] The thiophene content in the refined product was measured by OI5380 PFPD pulse flame photometry to evaluate the desulfurization efficiency of the refining process. The results are shown in Figure 4 .

[0075] pass Figure 2-4 It can be seen that the catalytic hydrogenation catalyst prepared by the present invention shows a higher liquid product yield and BTX retention rate, and the thiophene content in the product is lower, which proves that the high-temperature co-carbonization of rectorite and pollen, the introduction of hexamethylenediamine and 1,2-dibromopropane, and the impregnation of the catalyst prepared based on the Kirkendall effect are all helpful to improve the catalytic hydrogenation efficiency and desulfurization efficiency of coking crude benzene, and the catalytic hydrogenation catalyst prepared by the present invention has more excellent catalytic hydrogenation performance and desulfurization performance than commercially available catalysts.

[0076] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0077] The present invention and its implementation methods are described above, which is not restrictive. The drawings are only one of the implementation methods of the present invention, and the actual application is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A method for catalytic hydrogenation refining of coking crude benzene, characterized in that: The steps include: S1. Preparation of catalyst carrier: treating pollen with ultrasonic treatment of deionized water for 1-2h, adding it to a mixed solution of anhydrous ethanol and formaldehyde in a volume ratio of 1:1, stirring for 1-2h, filtering, washing with deionized water, and then mixing with rectorite powder, putting them together in a tube furnace, heating to 300-400°C and calcining for 1-2h under nitrogen at a flow rate of 150-200mL / min to obtain rectorite-modified carbonized pollen, adding the rectorite-modified carbonized pollen to a high-pressure hydrothermal reactor lined with polytetrafluoroethylene, adding hexamethylenediamine, 1,2-dibromopropane and acetonitrile, stirring for 20-50min, washing with deionized water after the reaction, and drying at 80°C for 8-12h to obtain the catalyst carrier; S2, preparing a catalyst impregnation solution: mixing molybdenum powder, cobalt powder and nickel powder with a phosphorus source under a nitrogen atmosphere, heating to 300-350° C. to form a phosphide, then dispersing the obtained phosphide in oleylamine at a high speed, heating to 250° C. under nitrogen protection, maintaining for 10-50 min, and then introducing a mixed gas of oxygen and nitrogen to form a metal oxide with a hollow structure, that is, obtaining the catalyst impregnation solution; S3, preparing a catalytic hydrogenation catalyst: immersing the catalyst carrier in a catalyst impregnation solution for 5-8 hours, drying at 80° C. for 3-5 hours, and then further drying at 110° C. for 5-8 hours to obtain the catalytic hydrogenation catalyst; S4, catalytic hydrogenation refining: the prepared catalytic hydrogenation catalyst is filled into the pre-reactor and the main reactor of the two-stage reactor, the coking crude benzene first passes through the heavy component removal tower, and then enters the pre-reactor under the pressure and speed increase of the pressure pump, and the product of the pre-reactor is passed into the main reactor for further catalytic hydrogenation; S5. Component separation: After the reaction products of the main reactor are cooled to room temperature, they are separated by a three-phase separator, and the liquid components are sent to a stabilization tower, where acidic gases containing hydrogen sulfide and ammonia are removed. High-purity pure benzene, pure toluene and xylene are then obtained through fractionation.

2. A method for catalytic hydrogenation refining of coked crude benzene according to claim 1, characterized in that: The mass ratio of the pollen, rectorite powder, hexamethylenediamine, 1,2-dibromopropane and acetonitrile is 10-30:15-40:5-8:8-15:50-80.

3. A method for catalytic hydrogenation refining of coked crude benzene according to claim 2, characterized in that: The mass ratio of the molybdenum powder, cobalt powder, nickel powder, phosphorus source and oleylamine is 5-10:1-3:1-3:10-20:50-80.

4. A method for catalytic hydrogenation refining of coked crude benzene according to claim 3, characterized in that: The phosphorus source is one of red phosphorus, white phosphorus and trioctylphosphine.

5. A method for catalytic hydrogenation refining of coked crude benzene according to claim 4, characterized in that: The flow rate of the mixed gas of oxygen and nitrogen is 150-200 mL / min, and the flow ratio of oxygen to nitrogen is 2:

1.

6. A method for catalytic hydrogenation refining of coked crude benzene according to claim 5, characterized in that: The temperature of the pre-reactor is 180-240° C., and the pressure is 3.5-5 MPa.

7. A method for catalytic hydrogenation refining of coked crude benzene according to claim 6, characterized in that: The temperature of the main reactor is 320-370°C, and the pressure is 3.5-5MPa.

8. A method for catalytic hydrogenation refining of coking crude benzene according to claim 7, characterized in that: The temperature of the heavy component removal tower is 100-200°C.

9. A method for catalytic hydrogenation refining of coked crude benzene according to claim 8, characterized in that: The flow rate of the coking crude benzene entering the pre-reactor is 0.5-2 m / s.

10. A method for catalytic hydrogenation refining of coking crude benzene according to claim 9, characterized in that: The temperature of the stabilization tower is 50-100°C.

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