A method and system for hydrogenating ethylene tar

Abstract

This invention discloses a method for hydrogenating ethylene tar. The method includes the following steps: ethylene tar feedstock and hydrogen-containing gas are mixed and sequentially passed through a low-temperature hydrogenation reaction zone and a high-temperature hydrogenation reaction zone, followed by separation to obtain the final liquid product. The reaction temperature in the low-temperature hydrogenation reaction zone is 80~175℃, preferably 100~175℃; the reaction temperature in the high-temperature hydrogenation reaction zone is 180~380℃, preferably 180~360℃. Based on the molecular structure and reaction characteristics of olefins in ethylene tar, this method sets up a two-stage hydrogenation process (low-temperature and high-temperature) to remove olefins from the ethylene tar in stages, thus solving the problem of coking in the equipment during ethylene tar processing.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical technology and relates to a method and system for hydrotreating oil products, specifically a method and system for hydrotreating ethylene tar. Background Technology

[0002] Ethylene tar is a high-temperature condensation product of steam cracking to produce ethylene, accounting for approximately 10-15 wt.% of ethylene production. Ethylene tar has a complex composition, high content of unsaturated hydrocarbons such as aromatics and aromatic olefins, and poor oxidation stability and compatibility. Based on practical processing experience, it is considered a very difficult oil product to utilize. With the continuous expansion of domestic ethylene production capacity, how to achieve high-value-added utilization of ethylene tar has become a challenge for the petrochemical industry.

[0003] Patent CN106554795A discloses a method for utilizing ethylene tar. The method includes the following steps: Shengli crude oil and ethylene tar are mixed evenly and then fed into a crude oil distillation unit for distillation. First, atmospheric distillation separates gasoline and diesel fractions, then vacuum distillation separates diesel, wax oil, and residue oil fractions. Patent CN103773497A discloses a method for increasing fuel oil production. This method fractionates ethylene tar into light and heavy fractions. The heavy fraction is mixed with conventional coking feedstock and subjected to delayed coking to obtain coking products. These coking products, along with C9 components from an ethylene unit, are fed into a coking distillation tower for distillation to obtain coking gasoline and coking diesel fractions. The obtained coking gasoline fraction is hydrorefined, and the coking diesel is mixed with the light ethylene tar fraction and subjected to hydrotreating. The resulting products are separated to obtain gasoline and diesel products. Both of the aforementioned patents describe fractional distillation of ethylene tar. However, when ethylene tar is directly distilled under atmospheric and vacuum conditions, severe coking occurs in parts such as the heating furnace, heat exchanger, and bottom of the distillation column after a period of operation, causing the distillation column to malfunction and forcing the entire unit to shut down.

[0004] Patent CN114540059A discloses a combined process, system, and the resulting needle coke for the production of needle coke from heavy oil. The method includes the following steps: heavy oils such as ethylene tar are hydrotreated to separate light and heavy components. The light components enter an electrostatic descaling unit to obtain deashed oil, which then enters a solvent extraction unit. The extracted oil is then fed into a delayed coking unit to produce needle coke. In this method, the ethylene tar undergoes hydrotreatment before cutting to remove olefins. However, the hydrotreatment reaction temperature is 360-400℃. At this temperature, the heavy components undergo extensive condensation and coking reactions, further increasing the difference between the light and heavy components in the ethylene tar. This leads to severe phase separation of the inherently unstable ethylene tar, increasing the likelihood of coking and blockage in the unit. Summary of the Invention

[0005] Compared to conventional heavy feedstocks such as residual oil or coking wax oil, ethylene tar contains a large amount of unsaturated olefins. The C=C double bonds rapidly undergo condensation reactions to form coke, resulting in a lower initial coking temperature for ethylene tar. In-depth research into the molecular structure and reaction characteristics of ethylene tar has revealed that olefin molecules with different structures have varying electron cloud densities, thus affecting their adsorption and reaction rates on the catalyst surface. Based on adsorption and reaction rates, the olefins in ethylene tar can be divided into Type I and Type II olefins. Type I olefins include polyolefins and a small number of highly reactive monoolefins. They have high electron cloud densities, readily adsorb and react on the catalyst surface, and are relatively temperature-sensitive. These olefins are the fundamental reason for the lower initial coking temperature of ethylene tar. Type II olefins refer to most monoolefins. Compared to Type I olefins, Type II olefins have lower electron cloud densities, are less prone to adsorption and reaction on the catalyst surface, are less temperature-sensitive, and have a relatively higher coking temperature. Therefore, strict temperature control is necessary during the removal of Type I olefins; otherwise, severe coking can easily occur at locations such as heat exchangers, reactor inlets, or inside the reactor bed, affecting the normal operation of the unit. In the removal of type II olefins, the hydrogenation reaction temperature can be set higher to improve catalyst performance. The technical solution of this invention is based on the above findings.

[0006] This invention provides a method and system for hydrogenating ethylene tar. The method, based on the molecular structure and reaction characteristics of olefins in ethylene tar, sets up a two-stage hydrogenation process with low temperature and high temperature, thereby removing olefins from ethylene tar in different sections and solving the problem of coking in the equipment during the processing and utilization of ethylene tar.

[0007] A method for hydrogenating ethylene tar, comprising the following steps: ethylene tar feedstock and hydrogen-containing gas are mixed and sequentially passed through a low-temperature hydrogenation reaction zone and a high-temperature hydrogenation reaction zone, followed by separation to obtain the final liquid product; the reaction temperature in the low-temperature hydrogenation reaction zone is 80~175℃, preferably 100~175℃; the reaction temperature in the high-temperature hydrogenation reaction zone is 180~380℃, preferably 180~360℃.

[0008] Furthermore, in the above method, the olefin content of the final liquid product can be controlled by adjusting the temperature difference between the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone, thereby controlling the application of the liquid product.

[0009] Furthermore, in the above method, the temperature difference between the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone is 5~85℃, preferably 10~80℃. The olefin content of the final liquid product is controlled to be 3.0~9.0 mol%, preferably 4.0~8.0 mol%, which can be used as a raw material for the production of low-sulfur petroleum coke.

[0010] Furthermore, in the above method, the temperature difference between the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone is 85~250℃, preferably 85~220℃. The olefin content of the final liquid product is controlled to be 0~2.0 mol%, preferably 0~1.0 mol%, which can be used as a blending component for low-sulfur marine fuel.

[0011] Furthermore, in the above method, the low-temperature hydrogenation reaction zone is filled with a first hydrogenation treatment catalyst, and the high-temperature hydrogenation reaction zone is filled with a second hydrogenation treatment catalyst; the first hydrogenation treatment catalyst and the second hydrogenation treatment catalyst may be the same or different, preferably different.

[0012] Furthermore, in the above method, the first and second hydrogenation treatment catalysts comprise a support and an active metal; the support comprises a porous, refractory inorganic oxide such as alumina, and, depending on actual needs, at least one of various other additives such as P, Si, F, and B may be selectively added; the active metal is generally a Group VIB and / or Group VIII metal, preferably one or more of W, Mo, Co, and Ni; based on the total weight of the catalyst, the mass fraction of the active metal as an oxide is 5-35%. The first and second hydrogenation treatment catalysts can be commercial catalysts or prepared according to methods existing in the art; they can be oxidizing catalysts and / or sulfur-supported catalysts.

[0013] Furthermore, in the above method, the first hydrogenation catalyst and the second hydrogenation catalyst have a pore size of 5~15 nm, a B / L acid ratio of 0.1~0.5, and a total infrared acid content of 0.2~0.45 mmol / g.

[0014] Furthermore, in the above method, the specific surface area of ​​the first hydrotreating catalyst and the second hydrotreating catalyst is 150–300 m². 2 / g, preferably 160~280 m 2 / g; pore volume is 0.2~0.6mL / g, preferably 0.25~0.55 mL / g.

[0015] Furthermore, in the above method, the pore size of the second hydrogenation catalyst is 1 to 10 nm smaller than that of the first hydrogenation catalyst, preferably 2 to 8 nm.

[0016] Furthermore, in the above method, the B / L acid ratio of the second hydrogenation catalyst is 0.05 to 0.2 smaller than that of the first hydrogenation catalyst, preferably 0.1 to 0.2.

[0017] Furthermore, in the above method, the total infrared acidity of the second hydrogenation catalyst is 0.05~0.20 mmol / g higher than that of the first hydrogenation catalyst, preferably 0.05~0.15 mmol / g.

[0018] Furthermore, in the above method, the active metal content of the second hydrogenation catalyst is 1 to 15 wt% lower than that of the first hydrogenation catalyst, preferably 2 to 12 wt%.

[0019] Furthermore, in the above method, the volume ratio of the first hydrogenation catalyst loaded in the low-temperature hydrogenation reaction zone to the second hydrogenation catalyst loaded in the high-temperature hydrogenation reaction zone is (20~50):100, preferably (50~80):100.

[0020] Furthermore, in the above method, at least one hydrogenation reactor is provided in both the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone; even further, the hydrogenation reactor can be a trickle bed reactor, a fluidized bed reactor, or a tubular reactor; it can be a single reactor type or a combination of one or more of these types.

[0021] Furthermore, in the above method, while processing the ethylene tar feedstock, hydrocarbon-containing feedstock can also be blended. The hydrocarbon-containing feedstock and the ethylene tar feedstock are mixed with hydrogen-containing gas and then sequentially passed through a low-temperature hydrogenation reaction zone and a high-temperature hydrogenation reaction zone before separation to obtain the final liquid product. The hydrocarbon-containing feedstock can be selected from one or more of catalytic gasoline, catalytic diesel, catalytic wax oil, catalytic slurry, coking gasoline, coking diesel, and coking wax oil.

[0022] Furthermore, in the above method, the hydrogen-containing gas is hydrogen or a mixture of hydrogen and other gases; the other gases may be high-part gas and / or low-part gas from the hydrogenation unit; even further, the high-part gas may come from hydrogenation units with a hydrogen partial pressure in the range of 4.0~20.0 MPa, including hydrogenation units for naphtha, diesel, wax oil and residual oil.

[0023] Furthermore, in the above method, the operating conditions of the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone are generally as follows: reaction pressure 3~30 MPa, preferably 4~25 MPa; volume hourly space velocity 0.1~10.0 h⁻¹ -1 Preferably, the time is 0.2~4.0 h. -1 The hydrogen-to-oil volume ratio is 200-1000, preferably 250-800.

[0024] Furthermore, in the above method, the final liquid product obtained after separation can be used to preheat the feedstock oil or mixed with the feedstock oil as circulating oil.

[0025] A second aspect of the present invention provides a hydrotreating system for ethylene tar, the hydrotreating system comprising:

[0026] The low-temperature hydrogenation reaction zone is used to receive ethylene tar feedstock and hydrogen-containing gas, and to carry out hydrogenation treatment under the action of the first hydrogenation treatment catalyst.

[0027] The high-temperature hydrogenation reaction zone is used to receive the reaction effluent and hydrogen-containing gas from the low-temperature hydrogenation reaction zone, and the reaction is carried out under the action of the second hydrogenation treatment catalyst.

[0028] The gas-liquid separation unit receives the reaction effluent from the high-temperature hydrogenation reaction zone and separates it to obtain gaseous and liquid products.

[0029] Furthermore, in the aforementioned hydrogenation system, a feedstock heater is not required; only a hydrogen heater and a start-up furnace are needed. After heat exchange, the ethylene tar feedstock and liquid product are mixed with hydrogen-containing gas obtained from the hydrogen heater before entering the low-temperature hydrogenation reaction zone.

[0030] Furthermore, in the above-mentioned hydrogenation treatment system, both the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone are equipped with at least one hydrogenation reactor; even further, the hydrogenation reactor can be a trickle bed reactor, a fluidized bed reactor, or a tubular reactor, and can be a single reactor type or a combination of one or more of these types.

[0031] Furthermore, in the aforementioned hydrogenation system, the gas-liquid separation unit can be configured using existing techniques in the art. Specifically, in this invention, the gas-liquid separation unit typically includes a hot high-pressure separator, a hot low-pressure separator, a cold high-pressure separator, and a cold low-pressure separator.

[0032] Compared with the prior art, the beneficial effects of the ethylene tar hydrogenation treatment method and system provided by the present invention are as follows:

[0033] 1. This invention proposes for the first time a method for the staged removal of olefins from ethylene tar, which greatly improves the operational stability of ethylene tar processing units. Based on the study of the molecular structure and reaction characteristics of ethylene tar, a low-temperature hydrogenation reaction zone and a high-temperature hydrogenation reaction zone are sequentially set along the liquid phase flow direction. The purpose is to remove type I and type II olefins separately, removing different olefins in ethylene tar under different reaction conditions. This can effectively avoid olefin coking while ensuring the removal effect, greatly improving the operational stability of ethylene tar hydrogenation treatment and subsequent processing units.

[0034] 2. In the ethylene tar hydrotreating method provided by the present invention, hydrotreating catalysts with different properties are packed in a graded manner in the low-temperature hydrotreating reaction zone and the high-temperature hydrotreating reaction zone. Ethylene tar comes into contact with the hydrotreating catalysts packed in the low-temperature and high-temperature hydrotreating reaction zones sequentially along the flow direction. The first hydrotreating catalyst packed in the low-temperature hydrotreating reaction zone has a low total infrared acidity and a high Brønsted acid / Low acid ratio, which can prevent the formation of excessive adsorption between type I olefins in ethylene tar and L acid centers (type I olefins in ethylene tar are more easily adsorbed onto L acid centers on the catalyst surface), thus avoiding condensation and coking reactions. The second hydrotreating catalyst packed in the high-temperature hydrotreating reaction zone has a high total infrared acidity and a low Brønsted acid / L acid ratio, which can suppress the occurrence of isomerization reactions, reduce steric hindrance effects, and thus improve the removal efficiency of type II olefins.

[0035] 3. In the ethylene tar hydrogenation treatment method provided by the present invention, the type I olefins contained in ethylene tar have a high electron cloud density and the molecules are prone to aggregation due to non-bonding interactions. Therefore, compared with the second hydrogenation treatment catalyst packed in the high-temperature hydrogenation reaction zone, the first hydrogenation treatment catalyst packed in the low-temperature hydrogenation reaction zone has a larger probable pore size, which helps to reduce diffusion restriction during the reaction process.

[0036] 4. In the ethylene tar hydrotreating method provided by this invention, the active metal content of the first hydrotreating catalyst packed in the low-temperature hydrotreating reaction zone is higher than that of the second hydrotreating catalyst in the high-temperature hydrotreating reaction zone. The higher catalyst activity in the low-temperature hydrotreating reaction zone can increase the removal efficiency of type I olefins; while the lower catalyst activity in the high-temperature hydrotreating reaction zone can reduce the intensity of the reaction and improve the stability of the unit operation.

[0037] 5. This invention effectively reduces energy consumption by setting up a reasonable heat exchange scheme. The liquid phase product is used to preheat the feedstock oil, which can make full use of the heat generated by the olefin hydrogenation saturation reaction in ethylene tar, eliminating the need for a feedstock heating furnace. The heat supply of the reaction system is provided by the heat of reaction, which greatly reduces heat consumption. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the process flow for the ethylene tar hydrogenation treatment method of the present invention.

[0039] Among them, 1-raw material oil; 2-hydrogen-containing gas; 3-low temperature hydrogenation reaction zone; 4-first reactant; 5-high temperature hydrogenation reaction zone; 6-second reactant; 7-gas-liquid separation zone; 8-gas phase product; 9-liquid phase product.

[0040] Figure 2 This is a schematic diagram of the process flow of the ethylene tar hydrogenation treatment method used in Comparative Example 1 of the present invention.

[0041] Among them, 1-raw material oil; 2-hydrogen-containing gas; 3-hydrogenation reaction zone; 4-first reactant; 5-gas-liquid separation zone; 6-gas phase product; 7-liquid phase product. Implementation

[0042] The technical solution and effects of the present invention will be further described below with reference to the accompanying drawings and embodiments, but the invention is not limited to the following embodiments.

[0043] The specific embodiments of the present invention will be described in detail below. However, it should be noted that the scope of protection of the present invention is not limited to these specific embodiments, but is determined by the claims in the appendix.

[0044] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0045] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0046] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0047] In this document, all numeric values ​​of parameters (e.g., quantity or condition) should be understood to be modified by the term “about” in all cases, regardless of whether “about” actually appears before the numeric value.

[0048] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this instruction manual are based on weight, and the pressure is gauge pressure.

[0049] In the context of this specification, any two or more embodiments of the present invention can be arbitrarily combined, and the resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0050] like Figure 1As shown, the raw material oil 1 and hydrogen-containing gas 2 are mixed and then enter the low-temperature hydrogenation reaction zone 3. The first reactant 4 is mixed with hydrogen-containing gas 2 and then enters the high-temperature hydrogenation reaction zone 5. The second reactant 6 is then entered the gas-liquid separation zone 7, where gaseous product 8 and liquid product 9 are separated.

[0051] like Figure 2 As shown, the raw material oil 1 and hydrogen-containing gas 2 are mixed and then enter the hydrogenation reaction zone 3. The resulting first reactant 4 enters the gas-liquid separation zone 5, where gaseous product 6 and liquid product 7 are separated.

[0052] Examples 1-5

[0053] One fixed-bed hydrogenation reactor was set up in both the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone, respectively loaded with a first hydrogenation treatment catalyst and a second hydrogenation treatment catalyst. Both catalysts used alumina as a support, and the active metal components included molybdenum and nickel. The specific properties of the catalysts are shown in Table 1. The properties of the ethylene tar feedstock used are shown in Table 2. The catalyst loading schemes and process conditions for Examples 1-5 are shown in Tables 3-7, and the experimental results are shown in Tables 8-9.

[0054] Table 1 Physicochemical properties of catalyst A and catalyst B

[0055]

[0056] Table 2 Properties of Ethylene Tar Feedstock

[0057]

[0058] Table 3 Catalyst loading scheme and process conditions in Example 1

[0059]

[0060] Table 4 Catalyst loading scheme and process conditions in Example 2

[0061]

[0062] Table 5 Catalyst loading scheme and process conditions in Example 3

[0063]

[0064] Table 6 Catalyst loading scheme and process conditions in Example 4

[0065]

[0066] Table 7 Catalyst loading scheme and process conditions in Example 5

[0067]

[0068] Table 8 Results of experiments in Examples 1, 3 and 4

[0069]

[0070] Table 9 Results of tests in Examples 2 and 5

[0071]

[0072] As shown in Tables 8 and 9, the liquid products in Examples 1, 3 and 4 can be used as blending components for low-sulfur marine fuel, and the liquid products in Examples 2 and 5 can be used as raw materials for the production of low-sulfur petroleum coke.

[0073] Comparative Example 1

[0074] Comparative Example 1 did not include a low-temperature hydrogenation reaction zone; the feedstock directly entered the high-temperature reaction zone. The high-temperature reaction zone contained a fixed-bed hydrogenation reactor, loaded with the first hydrogenation catalyst, A. The process conditions were as follows: reaction pressure 9.0 MPa, reaction temperature 260℃, hydrogen-to-oil volume ratio 360, and volume hourly space velocity (VHSV) 1.0 h⁻¹. -1 The results of Comparative Example 1 are shown in Table 10.

[0075] Table 10. Implementation Results of the Comparative Study

[0076]

[0077] The voltage drop of the devices in Examples 1-5 and Comparative Example 1 is shown in Table 11.

[0078] Table 11 Device voltage drops in Examples 1-5 and Comparative Example 1

[0079]

Claims

1. A method for hydrogenating ethylene tar, characterized in that: The processing method includes the following steps: ethylene tar feedstock and hydrogen-containing gas are mixed and then sequentially passed through a low-temperature hydrogenation reaction zone and a high-temperature hydrogenation reaction zone, followed by separation to obtain the final liquid product; the reaction temperature in the low-temperature hydrogenation reaction zone is 80~175℃; the reaction temperature in the high-temperature hydrogenation reaction zone is 180~380℃. The olefin content of the final liquid product can be controlled by adjusting the temperature difference between the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone, thereby controlling the application of the liquid product. The low-temperature hydrogenation reaction zone is filled with a first hydrogenation treatment catalyst, and the high-temperature hydrogenation reaction zone is filled with a second hydrogenation treatment catalyst. The pore size of the second hydrotreating catalyst is 1-10 nm smaller than that of the first hydrotreating catalyst. The B / L acid ratio of the second hydrotreating catalyst is 0.05 to 0.2 lower than that of the first hydrotreating catalyst; The total infrared acidity of the second hydrotreating catalyst is 0.05~0.20 mmol / g higher than that of the first hydrotreating catalyst; The active metal content of the second hydrotreating catalyst is 1-15 wt% lower than that of the first hydrotreating catalyst; The volume ratio of the first hydrogenation catalyst loaded in the low-temperature hydrogenation reaction zone to the second hydrogenation catalyst loaded in the high-temperature hydrogenation reaction zone is (20~50):

100.

2. The method according to claim 1, characterized in that: The reaction temperature in the low-temperature hydrogenation reaction zone is 100~175℃; the reaction temperature in the high-temperature hydrogenation reaction zone is 180~360℃.

3. The method according to claim 1, characterized in that: The temperature difference between the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone is 5~85℃, and the olefin content of the final liquid product is controlled to be 3.0~9.0 mol.

4. The method according to claim 3, characterized in that: The temperature difference between the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone is 10~80℃, and the olefin content of the final liquid product is controlled to be 4.0~8.0 mol.

5. The method according to claim 1, characterized in that: The temperature difference between the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone is 85~250℃, and the olefin content of the final liquid product is controlled to be 0~1.0 mol.

6. The method according to claim 5, characterized in that: The temperature difference between the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone is 85~220℃, and the olefin content of the final liquid product is controlled to be 0~1.0 mol.

7. The method according to claim 1, characterized in that: The first and second hydrogenation catalysts have a pore size of 5-15 nm, a B / L acid ratio of 0.1-0.5, and a total acid content of 0.2-0.45 mmol / g.

8. The method according to claim 1, characterized in that: The specific surface area of ​​the first and second hydrotreating catalysts is 150–300 m². 2 / g; pore volume is 0.2~0.6mL / g.

9. The method according to claim 8, characterized in that: The specific surface area of ​​the first and second hydrotreating catalysts is 160~280 m². 2 / g; pore volume is 0.25~0.55 mL / g.

10. The method according to claim 1, characterized in that: The pore size of the second hydrotreating catalyst is 2-8 nm smaller than that of the first hydrotreating catalyst.

11. The method according to claim 1, characterized in that: The B / L acid ratio of the second hydrotreating catalyst is 0.1 to 0.2 lower than that of the first hydrotreating catalyst.

12. The method according to claim 1, characterized in that: The total infrared acidity of the second hydrogenation catalyst is 0.05~0.15 mmol / g higher than that of the first hydrogenation catalyst.

13. The method according to claim 1, characterized in that: The active metal content of the second hydrotreating catalyst is 2-12 wt% lower than that of the first hydrotreating catalyst.

14. The method according to claim 1, characterized in that: The volume ratio of the first hydrogenation catalyst loaded in the low-temperature hydrogenation reaction zone to the second hydrogenation catalyst loaded in the high-temperature hydrogenation reaction zone is (50~80):

100.

15. The method according to claim 1, characterized in that: While processing ethylene tar feedstock, hydrocarbon-containing feedstock is also blended. The hydrocarbon-containing feedstock and ethylene tar feedstock are mixed with hydrogen-containing gas and then passed sequentially through a low-temperature hydrogenation reaction zone and a high-temperature hydrogenation reaction zone before separation to obtain the final liquid product. The hydrocarbon-containing feedstock is selected from one or more of catalytic gasoline, catalytic diesel, catalytic wax oil, catalytic slurry, coking gasoline, coking diesel, and coking wax oil.

16. The method according to claim 1, characterized in that: The hydrogen-containing gas is hydrogen or a mixture of hydrogen and other gases; the other gases are high-splitting and / or low-splitting gases from the hydrogenation unit.

17. The method according to claim 1, characterized in that: The operating conditions for the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone are as follows: reaction pressure 3~30 MPa; volume hourly space velocity 0.1~10.0 h⁻¹ -1 The hydrogen-to-oil volume ratio is 200-1000.

18. The method according to claim 17, characterized in that: The operating conditions for the low-temperature hydrogenation reaction zone and the high-temperature hydrogenation reaction zone are as follows: reaction pressure 4~25 MPa; volume hourly space velocity 0.2~4.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 250-800.

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