A method for hydrogenating coal tar in a slurry bed

Abstract

The present disclosure relates to a method for hydrogenating coal tar in a slurry bed, the method comprising: sending a coal tar raw material and a hydrogenation catalyst into a mixing tank for mixing to obtain a mixed oil slurry; sending the mixed oil slurry and hydrogen into a slurry bed reactor for catalytic hydrogenation reaction to obtain a hydrogenation reaction product; then separating the hydrogenated modified oil from the hydrogenation reaction product; the hydrogenation catalyst comprises a carrier and an active metal component; the carrier is a carbon-based carrier, and the active metal element in the active metal component is selected from one or more of Fe, Co and Ni; the active metal element in the hydrogenation catalyst exists in the form of a metal oxide; the particle size of the active metal component in the hydrogenation catalyst is 5-40nm. The method disclosed herein can improve the removal rate of mechanical impurities, the yield of liquid products and anti-coking performance.

Description

Technical Field

[0001] The present disclosure relates to the field of petrochemical industry, and in particular, to a slurry bed coal tar hydrogenation method. Background Art

[0002] Coal tar is a liquid byproduct produced during the dry distillation and gasification of coal. Coal tar contains a large amount of unsaturated components such as aromatics and olefins, high content of heteroatoms such as sulfur, nitrogen and oxygen, high content of mechanical impurities, metals and asphaltene, and high residual carbon value. The composition characteristics of coal tar increase its processing difficulty, making it difficult to directly use traditional heavy oil processing technology for deep processing of coal tar, and it must undergo pre-hydrogenation treatment. At present, the pretreatment processes for fixed-bed coal tar hydrogenation mainly include distillation, filtration, coking, ebullating bed hydrogenation and suspended bed hydrogenation.

[0003] Patent CN201010217358.1 discloses a coal tar suspended bed hydrogenation method with a heterogeneous catalyst, which performs a hydrocracking lightening reaction on the heavy fraction oil above 370°C in the coal tar, and most of the tail oil containing the catalyst after the light oil is separated from the reaction product is directly circulated to the suspended bed reactor for further lightening, and a small part of the tail oil is treated to remove the catalyst and then circulated to the suspended bed reactor, so that all or the maximum amount of heavy fraction oil is circulated to the suspended bed reactor for further lightening, and the removed catalyst is thrown out or regenerated, achieving the purpose of maximum production of light oil and catalyst recycling from coal tar, and improving the utilization efficiency of raw materials and catalysts. The raw material of the suspended bed reactor in the invention is the heavy fraction of coal tar above 370°C, and in the suspended bed reaction process provided by it, the asphaltenes in the heavy fraction above 370°C are more likely to polymerize and generate coke through free radical reaction, which increases the probability of blocking the internal components of the reactor and affects the normal operation of the device.

[0004] However, experiments have found that the existing hydrogenation methods have problems such as low removal efficiency of metal and mechanical impurities, low raw material adaptability, low liquid yield and low oil quality. Summary of the invention

[0005] The purpose of the present invention is to provide a method for hydrogenating coal tar in a slurry bed, which solves the problems existing in the prior art, such as low removal efficiency of metal and mechanical impurities, low raw material adaptability, low liquid yield and low oil quality.

[0006] In order to achieve the above-mentioned object, the present disclosure provides a method for hydrogenating coal tar in a slurry bed, the method comprising: feeding a coal tar raw material and a hydrogenation catalyst into a mixing tank for mixing to obtain a mixed oil slurry; feeding the mixed oil slurry and hydrogen into a slurry bed reactor for catalytic hydrogenation reaction to obtain a hydrogenation reaction product; and then separating the hydrogenated modified oil from the hydrogenation reaction product; the hydrogenation catalyst comprises a carrier and an active metal component; the carrier is a carbon-based carrier, and the active metal element in the active metal component is selected from one or more of Fe, Co and Ni; the active metal element in the hydrogenation catalyst exists in the form of metal oxides; the metal oxides include Fe 3 O 4 , Fe 2 O 3 , at least one of CoO and NiO; the particle size of the active metal component in the hydrogenation catalyst is 5-40nm.

[0007] Optionally, the carbon-based carrier includes one or more of carbon black, activated carbon, blue carbon, graphite and petroleum coke; the particle size of the carbon-based carrier is 10-100 μm, preferably 20-60 μm.

[0008] Optionally, based on the total weight of the hydrogenation catalyst, the content of the active metal element is 1-50% by weight, preferably 10-50% by weight; the average particle size of the hydrogenation catalyst is 10-200 μm, and the specific surface area is 10-400 m 2 / g.

[0009] Optionally, the preparation method of the hydrogenation catalyst includes: mixing a carrier and an active metal source solution, adding an alkaline substance to perform a precipitation reaction and perform solid-liquid separation to obtain a solid material; drying and calcining the solid material to obtain a calcined product; the calcination is performed in an inert atmosphere; the active metal source solution is selected from one or more of a nitrate solution, a sulfate solution and a chloride solution; the active metal element in the active metal source solution is selected from one or more of Fe, Co and Ni.

[0010] Optionally, the alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and ammonia solution; the content of active metal element in the active metal source solution is 0.5-5g relative to 100mL of the active metal source solution; the inert atmosphere is selected from one or more of nitrogen, argon and helium.

[0011] Optionally, the conditions of the precipitation reaction include: a reaction temperature of 20-100°C, a reaction time of 30-300 min, a stoichiometric ratio of the amount of the alkaline substance to the amount of the active metal element in the active metal source solution of (0.8-3):1; a drying temperature of 90-120°C and a time of 60-360 min; and a calcination temperature of 300-700°C and a time of 90-360 min.

[0012] Optionally, the reaction conditions of the catalytic hydrogenation reaction include: reaction temperature of 360-440°C, preferably 380-420°C; hydrogen partial pressure of 3.0-15.0 MPa, preferably 5.0-12.0 MPa; volume space velocity of 0.1-1.5 h -1 , preferably 0.2-1.0h -1 ; The volume ratio of hydrogen to oil is 100-2500, preferably 200-2000.

[0013] Optionally, based on the total weight of the coal tar feedstock and calculated on the weight of the active metal elements, the amount of the hydrogenation catalyst is 0.05-3.5 wt %, preferably 0.1-2.5 wt %.

[0014] Optionally, the method also includes sending the hydrogenation reaction product into a hot high-pressure separator for hot high-pressure separation to obtain hot high-fraction gas and a heavy oil phase; the operating conditions of the hot high-pressure separator include: a temperature of 280-400°C and a pressure of 8-18MPa; sending the hot high-fraction gas into a cold high-pressure separator for cold high-pressure separation to obtain circulating hydrogen and a light oil phase; mixing the circulating hydrogen with new hydrogen to obtain the hydrogen; the operating conditions of the cold high-pressure separator include: a temperature of 40-100°C and a pressure of 8-18MPa; sending the heavy oil phase into a solid-liquid separator for solid-liquid separation to obtain the hydrogenated modified oil.

[0015] Optionally, the mixed oil slurry also includes a vulcanizing agent, and the vulcanizing agent is selected from one or more of sublimated sulfur, carbon disulfide and dimethyl sulfide.

[0016] Through the above technical scheme, the hydrogenation catalyst and hydrogenation method used in the present invention can improve the removal rate of mechanical impurities (abbreviated as mechanical impurities), the yield of liquid products and anti-coking performance under the condition of high metal removal rate; and, by adopting the method of the present invention, there is no need to carry out dehydration and mechanical impurity removal processes and distillation treatment before the hydrogenation reaction, which can simplify the process, reduce energy consumption, and thus improve the adaptability of the reaction to raw materials.

[0017] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0019] Figure 1 It is a schematic diagram of a slurry bed coal tar hydrogenation method disclosed in the present invention.

[0020] Description of Reference Numerals

[0021] 1. Coal tar raw material; 2. Hydrogenation catalyst; 3. Mixing tank; 4. Feed tank; 5. High-pressure pump; 6. Feed heater; 7. Slurry bed reactor; 8. Hot high-pressure separator; 9. Cold high-pressure separator; 10. Circulating hydrogen; 11. New hydrogen; 12. Hydrogen preheater; 13. Hydrogen; 14. Solid-liquid separator; 15. Light oil phase; 16. Hydrogenated modified oil. DETAILED DESCRIPTION

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

[0023] The present invention provides a method for hydrogenating coal tar in a slurry bed, the method comprising: feeding a coal tar raw material and a hydrogenation catalyst into a mixing tank for mixing to obtain a mixed oil slurry; feeding the mixed oil slurry and hydrogen into a slurry bed reactor for catalytic hydrogenation reaction to obtain a hydrogenation reaction product; and then separating hydrogenated modified oil from the hydrogenation reaction product; the hydrogenation catalyst comprises a carrier and an active metal component; the carrier is a carbon-based carrier, and the active metal element in the active metal component is selected from one or more of Fe, Co and Ni; the active metal element in the hydrogenation catalyst exists in the form of metal oxides; the metal oxides include Fe 3 O 4 , Fe 2 O 3 , at least one of CoO and NiO; the particle size of the active metal component in the hydrogenation catalyst is 5-40nm.

[0024] Through the above technical scheme, the hydrogenation catalyst and hydrogenation method used in the present invention can improve the removal rate of mechanical impurities, the yield of liquid products and the anti-coking performance under the condition of high metal removal rate; and, the method of the present invention does not need to carry out dehydration and mechanical impurity removal processes and distillation treatment before the hydrogenation reaction, which can simplify the process, reduce energy consumption, and thus improve the adaptability of the reaction to raw materials.

[0025] In order to further improve the performance of the hydrogenation catalyst, the particle size of the active component in the hydrogenation catalyst is optimized. Specifically, the particle size of the active metal component in the hydrogenation catalyst is preferably 8-35 nm, and more preferably 10-30 nm. Since the hydrogenation catalyst is obtained by calcining the carrier and the active metal component after precipitation reaction, the particle size of the active metal component is smaller than that of the traditional impregnation method, thereby increasing the surface area in contact with the material and enhancing the activity of the hydrogenation catalyst.

[0026] In order to reduce the cost while ensuring the performance of the hydrogenation catalyst, it is necessary to limit the content of the active metal component in the hydrogenation catalyst to a certain extent. Specifically, based on the total weight of the hydrogenation catalyst, the content of the active metal element is 1-50% by weight, preferably 10-50% by weight, and more preferably 12-45% by weight.

[0027] In order to further enhance the catalytic performance of the hydrogenation catalyst, the average particle size and specific surface area of ​​the hydrogenation catalyst need to meet the corresponding standards. Specifically, the average particle size of the hydrogenation catalyst is 10-200 μm, and the specific surface area is 10-400 m 2 / g.

[0028] The carbon-based carrier of the hydrogenation catalyst may include one or more of carbon black, activated carbon, blue carbon, graphite and petroleum coke. In order to further enhance the performance of the hydrogenation catalyst, the particle size of the carbon-based carrier is 10-100 μm, preferably 20-60 μm, and more preferably 20-40 μm.

[0029] In one embodiment, a method for preparing a hydrogenation catalyst comprises: mixing a carrier and an active metal source solution, adding an alkaline substance to perform a precipitation reaction and performing solid-liquid separation to obtain a solid material; drying and calcining the solid material, and the calcined product obtained is a hydrogenation catalyst, and the calcination is performed in an inert atmosphere; wherein the carrier is a carbon-based carrier; the active metal source solution is selected from one or more of nitrates, sulfates and chlorides; and the active metal element in the active metal source solution is selected from one or more of Fe, Co and Ni.

[0030] In the above-mentioned embodiment, the hydroxide formed by the active metal component in the active metal source solution under alkaline conditions is precipitated on a carbon-based carrier as a carrier, and then subjected to a calcination treatment, so that the hydroxide coated on the surface of the carbon-based carrier can be converted into an oxide form. Compared with the method of preparing a supported catalyst by the traditional impregnation method, the method of the present application can obtain an active metal component with a smaller particle size, and thus can increase the contact area between the active metal component and the reaction material, thereby enhancing the activity of the hydrogenation catalyst. The hydrogenation catalyst provided by the present invention uses a carbon-based carrier, which can ensure that the metal removal rate, organic impurity removal rate and liquid yield are maintained at a high level while improving the reaction activity of the hydrogenation reaction and reducing the coking rate; and the active metal element in the hydrogenation catalyst is one or more of Fe, Co and Ni, which can reduce the price of the hydrogenation catalyst and reduce the difficulty of preparation.

[0031] In order to make the precipitation reaction more effective, the carbon-based carrier needs to be pretreated before the precipitation reaction; the pretreatment method is conventionally selected in the art and this application does not make any special requirements. For example, the carbon-based carrier is dried at a temperature of 100-130°C to remove moisture and some impurities therein.

[0032] In order to further enhance the activity of the precipitation reaction, the alkaline material can be directly added to the mixed material as solid powder or the alkaline material can be prepared into a solution and then added to the mixed material. The alkaline material is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and a 25%-28% ammonia solution.

[0033] The amount of active metal component added may be 0.5-5 g, preferably 0.8-4 g, and more preferably 1-3 g relative to 100 mL of the active metal source solution.

[0034] Among them, the conditions of the precipitation reaction include: the reaction temperature is 20-100°C, preferably 30-95°C, and more preferably 40-90°C; the reaction time is 30-300min, preferably 45-200min, and more preferably 60-90min; the stoichiometric ratio of the amount of the alkaline substance to the amount of the active metal element in the active metal source solution is (0.8-3):1, preferably (0.9-1.5):1, and more preferably (1-1.2):1.

[0035] In the above embodiment, the carbon-based carrier is placed in an active metal source solution and an alkaline substance is added thereto so that the active metal elements in the active metal source solution can react with the alkaline substance to generate a precipitate, and the precipitate will coat the carbon-based carrier in the mixed material; therefore, the surface of the carbon-based carrier is coated with a uniform precipitate, which can further enhance the performance of the hydrogenation catalyst.

[0036] After the precipitation reaction is completed, the reaction material is in a state where solid and liquid coexist, so the precipitation reaction product needs to be separated into solid and liquid. The solid-liquid separation method used in the present invention is conventionally selected in the art, and this application does not make special requirements. For example, the precipitation reaction product can be filtered and the obtained filter cake is the solid material.

[0037] In order to further remove the liquid in the solid material, the solid material needs to be dried at a temperature of 90-120° C. for 60-360 min.

[0038] In order to avoid the influence of moisture, oxygen and impurities in the air on the catalyst and thus improve the performance of the hydrogenation catalyst, the solid material is dried and sent to a tubular furnace for calcination under an inert atmosphere, wherein the inert atmosphere is selected from one or more of nitrogen, argon and helium.

[0039] The calcination temperature is 300-700°C, preferably 400-650°C, and more preferably 450-600°C; the calcination time is 90-360 min, preferably 150-330 min, and more preferably 200-300 min.

[0040] In a specific embodiment, the method for preparing a hydrogenation catalyst comprises:

[0041] (1) Preparation of carrier: The carbon-based carrier is dried and dehydrated at 100-130° C. and then crushed into powder with a particle size of 20-60 μm;

[0042] (2) After the metal source solution and the carrier are uniformly mixed, an alkaline substance is added during stirring to perform a precipitation reaction; wherein the conditions for the precipitation reaction are: a reaction temperature of 20-100° C. and a reaction time of 30-300 min; after the precipitation is washed, the obtained precipitation reaction product is subjected to solid-liquid separation to obtain a solid material;

[0043] (3) The solid material is dried at 90-120° C. for 60-360 min, placed in a tubular furnace, and calcined at 300-700° C. for 90-360 min under an inert atmosphere. The calcined product is the hydrogenation catalyst.

[0044] In one embodiment, the reaction conditions of the catalytic hydrogenation reaction include: reaction temperature of 360-440°C, preferably 380-420°C; hydrogen partial pressure of 3.0-15.0 MPa, preferably 5.0-12.0 MPa; volume space velocity of 0.1-1.5 h -1 , preferably 0.2-1.0h -1 ; The volume ratio of hydrogen to oil is 100-2500, preferably 200-2000.

[0045] In order to ensure economic benefits while improving the reaction activity of the catalytic hydrogenation reaction, it is necessary to limit the amount of the hydrogenation catalyst used. Specifically, based on the total weight of the coal tar feedstock and the weight of the active metal elements, the amount of the hydrogenation catalyst used is 0.05-3.5% by weight, preferably 0.1-2.5% by weight.

[0046] In one embodiment, in order to further improve the removal rate of impurities and metals from coal tar raw materials, a sulfiding agent can be added to the mixed oil slurry. Therefore, the mixed oil slurry also includes a sulfiding agent; wherein the sulfiding agent is selected from one or more of sublimated sulfur, carbon disulfide and dimethyl sulfide; relative to 1g of coal tar raw material, the ratio of the amount of the sulfiding agent (in terms of sulfur) to the amount of the hydrogenation catalyst (in terms of metal) is (1-2):1, preferably (1-1.5):1, and more preferably (1-1.2):1.

[0047] In one embodiment, the coal tar raw material is divided into two parts, namely the first part of coal tar and the second part of coal tar; the first part of coal tar and the hydrogenation catalyst are placed in a mixing tank and stirred and mixed at a temperature of 60-120°C and a stirring rate of 10-300r / min to obtain a premixed slurry; the premixed slurry is placed in a feed tank for standby use. The premixed slurry and the second part of coal tar are mixed to obtain a mixed oil slurry, which is then pressurized to 3-15MPa by a high-pressure pump and heated to 280-440°C with mixed hydrogen by a feed heater and then sent to a slurry bed reactor for hydrogenation reaction. The weight ratio of the first part of coal tar to the second part of coal tar is not specifically required in this disclosure and can be adaptively adjusted according to the requirements of the catalytic hydrogenation reaction.

[0048] In one embodiment, the method further includes: sending the hydrogenation reaction product into a hot high-pressure separator for hot high-pressure separation to obtain hot high-fraction gas and a heavy oil phase; sending the hot high-fraction gas into a cold high-pressure separator for cold high-pressure separation to obtain circulating hydrogen and a light oil phase; mixing the circulating hydrogen with new hydrogen to obtain the mixed hydrogen; and sending the heavy oil phase into a solid-liquid separator for solid-liquid separation to obtain the hydrogenated modified oil.

[0049] The circulating hydrogen and the new hydrogen are mixed and then heated to 300-440°C in a hydrogen preheater before being mixed with the mixed oil slurry.

[0050] In order to improve the quality of the light oil phase and the heavy oil phase, the two oil products need to be fully separated, and the cutting point between the light oil phase and the heavy oil phase is 280-420°C.

[0051] The conditions of the hot high-pressure separator include: a temperature of 280-400°C, preferably 300-390°C, and more preferably 360-380°C; a pressure of 8-18MPa, preferably 8.5-16MPa, and more preferably 9-14MPa.

[0052] The conditions of the cold high-pressure separator include: a temperature of 40-100°C, preferably 45-90°C, and more preferably 50-80°C; a pressure of 8-18MPa, preferably 8.5-16MPa, and more preferably 9-14MPa.

[0053] The solid-liquid separation method may be a conventional method in the art, for example, solid-liquid separation may be selected from centrifugation and / or filtration. In a specific embodiment of the present disclosure, solid-liquid separation is a filtration method, wherein the filtration pore size of the filter may be 5-50 μm.

[0054] The coal tar used in the present invention is preferably medium-low temperature coal tar and / or high temperature coal tar. The saturated content in high temperature coal tar is lower than that in medium-low temperature coal tar, while the residual carbon value is higher than that in medium-low temperature coal tar. High temperature coal tar has a high tendency to coke during processing and is difficult to process.

[0055] In one embodiment, the method for slurry bed coal tar hydrogenation comprises:

[0056] The coal tar raw material 1 is divided into two parts, namely the first part of coal tar and the second part of coal tar; the first part of coal tar and the hydrogenation catalyst 2 are placed in a mixing tank 3 and stirred and mixed at a temperature of 60-120°C and a stirring rate of 10-300r / min to obtain a premixed slurry; the premixed slurry is placed in a feed tank 4 for standby use. The premixed slurry and the second part of coal tar are mixed to obtain a mixed oil slurry, which is then pressurized to 3-15MPa by a high-pressure pump 5, heated to 280-440°C by a feed heater 6 with hydrogen 13, and then sent to a slurry bed reactor 7 for hydrogenation reaction.

[0057] The hydrogenation reaction product is sent to a hot high-pressure separator 8 for hot high-pressure separation to obtain hot high-fraction gas and a heavy oil phase; the hot high-fraction gas is sent to a cold high-pressure separator 9 for cold high-pressure separation to obtain circulating hydrogen 10 and a light oil phase 15; the circulating hydrogen 10 is mixed with new hydrogen 11 and heated in a hydrogen preheater 12 to obtain the hydrogen 13; the heavy oil phase is sent to a solid-liquid separator 14 for solid-liquid separation to obtain the hydrogenated modified oil 16.

[0058] The present invention is further illustrated by the following examples, but the present invention is not limited thereto. The feedstock oils used in the following examples and comparative examples are medium-low temperature coal tar and high temperature coal tar, and their specific properties are shown in Table 1. The hydrogenation catalyst B1 is a supported catalyst containing Mo-Ni, which is purchased.

[0059] Table 1 Coal tar properties

[0060]

[0061]

[0062] Preparation Example 1

[0063] (1) Preparation of carrier: The activated carbon was dried and dehydrated at 120°C and then crushed into powder with a particle size of 20-60 μm;

[0064] (2) Fe 2 (SO 4 ) 3 An aqueous ferric sulfate solution is prepared as a metal source solution, wherein the Fe content in the aqueous ferric sulfate solution is 2.4 g relative to 100 mL of the active metal source solution; after uniformly mixing 125 ml of the aqueous ferric sulfate solution with 5 g of the carrier, 20.16 g of a 28 wt % ammonia solution is added during stirring to perform a precipitation reaction; wherein the conditions for the precipitation reaction are: a reaction temperature of 60° C. and a reaction time of 60 min; after the precipitate is washed, the obtained precipitation reaction product is subjected to solid-liquid separation to obtain a solid material;

[0065] (3) The solid material was dried at 110°C for 300 min and then placed in a tube furnace under N 2 The calcined product was calcined at 490°C for 300 min under gas protection to obtain hydrogenation catalyst A1. The properties of hydrogenation catalyst A1 are shown in Table 2.

[0066] Preparation Example 2

[0067] (1) Preparation of carrier: The activated carbon was dried and dehydrated at 120°C and then crushed into powder with a particle size of 20-60 μm;

[0068] (2) Take Ni(NO 3 ) 2A nickel nitrate aqueous solution is prepared as a metal source solution, wherein the content of Ni in the nickel nitrate aqueous solution is 1 g relative to 100 mL of the active metal source solution; after 100 ml of the nickel nitrate aqueous solution is uniformly mixed with 5 g of a carrier, 1.82 g of sodium carbonate powder is added during stirring to perform a precipitation reaction; wherein the conditions for the precipitation reaction are: a reaction temperature of 90° C. and a reaction time of 60 min; after the precipitation is washed, the obtained precipitation reaction product is subjected to solid-liquid separation to obtain a solid material;

[0069] (3) The solid material was dried at 120°C for 300 min and then placed in a tube furnace under N 2 The calcined product was calcined at 500°C for 300 min under gas protection to obtain hydrogenation catalyst A2. The properties of hydrogenation catalyst A2 are shown in Table 2.

[0070] Preparation Comparative Example 1

[0071] (1) Preparation of carrier: The activated carbon was dried and dehydrated at 120°C and then crushed into powder with a particle size of 20-60 μm;

[0072] (2) With Fe(NO 3 ) 3 9H 2 O prepare an aqueous ferric nitrate solution as a metal source solution, wherein the content of Fe in the aqueous ferric nitrate solution is 1 g relative to 100 mL of the active metal source solution; impregnate 50 mL of the aqueous ferric nitrate solution onto 5 g of the above-mentioned carrier at an impregnation temperature of 60° C. for 180 min; after the impregnation, separate the obtained precipitation reaction product into a solid-liquid state to obtain a solid material;

[0073] (3) The solid material was dried at 110°C for 240 min and then placed in a tube furnace under N 2 The coal tar hydrogenation catalyst B2 was prepared by calcining at 600°C for 300 min under gas protection. The properties of the hydrogenation catalyst B2 are shown in Table 2.

[0074] Table 2 Properties of hydrogenation catalysts

[0075] Instance Number Preparation Example 1 Preparation Example 2 Preparation Comparative Example 1 catalyst A1 A2 B2 Fe, wt% 35.40 - 18.73 Ni, wt% - 15.56 - <![CDATA[Specific surface area of hydrogenation catalyst, m 2 / g]]> 50.3 60.2 55.8 Hydrogenation catalyst particle size, μm 24.5 19.2 21.0 Metal Phase <![CDATA[Fe 3 THE 4 ]]> NiO <![CDATA[Fe 3 THE 4 ]]> Metal component particle size, nm 22.37 12.25 43.3

[0076] Among them, the parameters of the hydrogenation catalyst test are as follows:

[0077] Metal composition: measured by iCAP7000 inductively coupled plasma optical emission spectrometer from Thermo Scientific.

[0078] Metal phase: Characterized on a D8ADVANCE X-ray diffractometer, Cu Kα radiation, λ=0.15418 nm, 2θ scanning range of 5°-70°, scanning rate of 4(°) / min.

[0079] Metal component particle size: calculated using the Scherrer formula based on data measured by an X-ray diffractometer.

[0080] Hydrogenation catalyst particle size: measured by MS3000 laser particle size analyzer.

[0081] Specific surface area of ​​hydrogenation catalyst: measured by ASAP2460 physical BET adsorption instrument.

[0082] Example 1

[0083] 200 g of medium-low temperature coal tar and 0.565 g of hydrogenation catalyst A1 are fed into a mixing tank 3 to be mixed to obtain a mixed oil slurry; the mixed oil slurry, 0.115 g of sublimated sulfur and hydrogen 13 are fed into a slurry bed reactor 7 to carry out a catalytic hydrogenation reaction to obtain a hydrogenation reaction product;

[0084] The hydrogenation reaction product is sent to the hot high-pressure separator 8 for hot high-pressure separation to obtain hot high-fraction gas and heavy oil phase; the hot high-fraction gas is sent to the cold high-pressure separator 9 for cold high-pressure separation to obtain circulating hydrogen 10 and light oil phase 15; the circulating hydrogen 10 is mixed with new hydrogen 11 and heated in the hydrogen preheater 12 to obtain the hydrogen 13; the heavy oil phase is sent to the solid-liquid separator 14 for solid-liquid separation to obtain the hydrogenated reformed oil 16. Among them, the conditions of the hot high-pressure separator include: temperature of 380°C and pressure of 8.5MPa; the conditions of the cold high-pressure separator include: temperature of 60°C and pressure of 8.5MPa.

[0085] The hydrogenation reaction operating conditions and reaction results are shown in Table 3.

[0086] Example 2

[0087] The method for slurry bed coal tar hydrogenation is the same as that in Example 1, except that the coal tar raw material is 200 g of high temperature coal tar. The hydrogenation reaction operating conditions and reaction results are shown in Table 3.

[0088] Example 3

[0089] The method for slurry bed coal tar hydrogenation is the same as that in Example 2, except that the hydrogenation catalyst is 1.286 g of hydrogenation catalyst A2. The hydrogenation reaction operating conditions and reaction results are shown in Table 3.

[0090] Comparative Example 1

[0091] The medium-low temperature coal tar, the promoter and the hydrogen are fed into a fixed bed reactor and contacted with the purchased hydrogenation catalyst B1 to carry out a catalytic hydrogenation reaction to obtain a hydrogenation reaction product; the reaction temperature is 380°C, the hydrogen partial pressure is 7.71MPa, and the space velocity is 1h -1The method for separating the hydrogenation reaction product to obtain the hydrogenated modified oil is the same as in Example 1. The hydrogenation reaction operating conditions and reaction results are shown in Table 3.

[0092] The hydrogenation catalyst B1 is a supported catalyst containing Mo—Ni, wherein the molybdenum content (calculated as metal) is 9.3 wt % and the nickel content (calculated as metal) is 2.52 wt %.

[0093] Comparative Example 2

[0094] The method for slurry bed coal tar hydrogenation is the same as that in Example 1, except that the hydrogenation catalyst is the hydrogenation catalyst B2 obtained in Preparation Comparative Example 1. The hydrogenation reaction operating conditions and reaction results are shown in Table 3.

[0095] Table 3 Hydrogenation reaction operating conditions and evaluation results

[0096]

[0097]

[0098] The hydrogen consumption, liquid yield, metal removal rate, organic impurity removal rate and coking rate of hydrotreated coal tar are calculated according to the following formula:

[0099]

[0100]

[0101]

[0102]

[0103]

[0104] As shown in the table, by comparing Examples 1-3 with Comparative Examples 1-2, it can be seen that the slurry bed process based on the hydrogenation catalyst disclosed herein and the fixed bed hydrogenation process based on the loaded Mo-Ni type catalyst show the advantages of high metal removal rate and liquid yield, and the slurry bed pretreatment process shows good advantages in offline impurities and anti-coking. At the same time, considering that the price of nickel is 30 times that of iron and the price of molybdenum is 40 times that of iron, the loaded iron catalyst is also preferably considered in consideration of economic cost. The catalyst is also cheap, simple to prepare, and can achieve efficient pretreatment of coal tar.

[0105] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0106] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0107] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for slurry bed coal tar hydrogenation, characterized in that: The method includes: The coal tar raw material and the hydrogenation catalyst are sent to a mixing tank for mixing to obtain a mixed oil slurry; the mixed oil slurry and hydrogen are sent to a slurry bed reactor for catalytic hydrogenation reaction to obtain a hydrogenation reaction product; and then the hydrogenated modified oil is separated from the hydrogenation reaction product; The hydrogenation catalyst comprises a carrier and an active metal component; the carrier is a carbon-based carrier, and the active metal element in the active metal component is selected from one or more of Fe, Co and Ni; The active metal element in the hydrogenation catalyst exists in the form of metal oxide; the metal oxide includes at least one of Fe3O4, Fe2O3, CoO and NiO; the particle size of the active metal component in the hydrogenation catalyst is 5-40nm; The preparation method of the hydrogenation catalyst comprises: The carrier and the active metal source solution are mixed, and an alkaline substance is added to perform a precipitation reaction and solid-liquid separation to obtain a solid material; the solid material is dried and roasted to obtain a roasted product; the roasting is performed in an inert atmosphere; The active metal source solution is selected from one or more of a nitrate solution, a sulfate solution and a chloride solution; the active metal element in the active metal source solution is selected from one or more of Fe, Co and Ni.

2. The method according to claim 1, characterized in that The carbon-based carrier includes one or more of carbon black, activated carbon, blue carbon, graphite and petroleum coke; the particle size of the carbon-based carrier is 10-100 μm.

3. The method according to claim 2, characterized in that The particle size of the carbon-based carrier is 20-60 μm.

4. The method according to claim 1, characterized in that: Based on the total weight of the hydrogenation catalyst, the content of the active metal element is 1-50% by weight; The average particle size of the hydrogenation catalyst is 10-200 μm, and the specific surface area is 10-400 m 2 / g.

5. The method according to claim 4, characterized in that Based on the total weight of the hydrogenation catalyst, the content of the active metal element is 10-50% by weight.

6. The method according to claim 1, characterized in that The alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and ammonia solution; The content of the active metal element in the active metal source solution is 0.5-5 g relative to 100 mL of the active metal source solution; The inert atmosphere is selected from one or more of nitrogen, argon and helium.

7. The method according to claim 1, characterized in that The conditions of the precipitation reaction include: a reaction temperature of 20-100° C., a reaction time of 30-300 min, and a stoichiometric ratio of the amount of the alkaline substance to the amount of the active metal element in the active metal source solution of (0.8-3):1; The drying temperature is 90-120°C and the drying time is 60-360min; The calcination temperature is 300-700° C. and the calcination time is 90-360 min.

8. The method according to claim 1, characterized in that The reaction conditions of the catalytic hydrogenation reaction include: reaction temperature of 360-440°C; hydrogen partial pressure of 3.0-15.0 MPa; volume space velocity of 0.1-1.5 h -1 ; The volume ratio of hydrogen to oil is 100-2500.

9. The method according to claim 8, characterized in that The reaction conditions of the catalytic hydrogenation reaction include: reaction temperature of 380-420°C; hydrogen partial pressure of 5.0-12.0 MPa; volume space velocity of 0.2-1.0 h -1 ; The volume ratio of hydrogen to oil is 200-2000.

10. The method according to claim 1, characterized in that Based on the total weight of the coal tar raw material, the amount of the hydrogenation catalyst used is 0.05-3.5% by weight, calculated by the weight of the active metal elements.

11. The method according to claim 10, characterized in that Based on the total weight of the coal tar raw material, the amount of the hydrogenation catalyst used is 0.1-2.5% by weight, calculated by the weight of the active metal elements.

12. The method according to claim 1, characterized in that The method further comprises sending the hydrogenation reaction product into a hot high-pressure separator for hot high-pressure separation to obtain hot high-fraction gas and heavy oil phase; the operating conditions of the hot high-pressure separator include: temperature of 280-400° C., pressure of 8-18 MPa; The hot high-fraction gas is sent to a cold high-pressure separator for cold high-pressure separation to obtain circulating hydrogen and light oil phase; the circulating hydrogen is mixed with new hydrogen to obtain the hydrogen; the operating conditions of the cold high-pressure separator include: temperature of 40-100°C and pressure of 8-18MPa; The heavy oil phase is sent to a solid-liquid separator for solid-liquid separation to obtain the hydrogenated modified oil.

13. The method according to claim 1, characterized in that The mixed oil slurry also includes a vulcanizing agent, which is selected from one or more of sublimated sulfur, carbon disulfide and dimethyl sulfide.

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