A method for preparing mesophase pitch, the product obtained, and a reaction apparatus.

Abstract

A method for preparing mesophase asphalt, the resulting product, and a reaction apparatus are disclosed. The method includes: mixing a narrow fraction of catalytic cracking slurry with anthracene to obtain a mixed feedstock; subjecting the mixed feedstock to high-pressure thermal conversion at 0.5-5 MPa; followed by atmospheric-pressure thermal conversion; solvent extraction to remove non-asphalt components from the reaction product; and vacuum distillation to separate distillate oil and residual solvent from the remaining material to obtain mesophase asphalt. The narrow fraction of the catalytic cracking slurry has a distillation range of 400°C to 490°C, with a distillation range width of 30°C-50°C. The method provided by this invention utilizes catalytic cracking slurry to induce the condensation of the aromatic compound anthracene without the use of a catalyst, resulting in mesophase asphalt with more uniform mesophase spheroid sizes. The apparatus provided by this invention is applicable to the above-mentioned method for producing mesophase asphalt.

Description

Technical Field

[0001] This invention relates to the field of heavy oil processing in petrochemicals, and more specifically, to a method and apparatus for producing mesophase bitumen through thermal conversion of heavy oil. Background Technology

[0002] Mesophase pitch is a precursor to high-end carbon materials such as mesophase carbon microspheres, mesophase pitch-based foamed carbon, mesophase pitch-based carbon fibers, and needle coke. Its structure determines the properties of all mesophase carbon materials. Mesophase carbon microspheres are a special type of carbon material. In addition to the general properties of carbon materials, they possess unique properties due to their spherical shape and layered structure, making them applicable to lithium-ion anode materials, nuclear graphite, high-end mechanical seals, and semiconductor manufacturing containers. Mesophase pitch-based foamed carbon is a porous carbon material produced by foaming mesophase pitch. It possesses excellent properties such as low density, high strength, high thermal conductivity, high electrical conductivity, fire resistance, impact resistance, and electromagnetic wave absorption, making it applicable to aerospace, chip thermal management, and impact-resistant and corrosion-resistant structural materials. Mesophase pitch-based carbon fibers possess a series of excellent properties such as high strength, high modulus, high temperature resistance, and low density, and are widely used in military, aerospace, and high-end industrial equipment. Needle coke is a high-quality material for manufacturing high-power and ultra-high-power electrodes. Graphite electrodes made from needle coke have advantages such as strong thermal shock resistance, high mechanical strength, good oxidation resistance, and low electrode consumption. All the aforementioned carbon materials use mesophase pitch as a precursor, and the microstructure of mesophase pitch is a crucial factor affecting their final performance and practical applications.

[0003] Currently, there are no reports of preparing mesophase pitch from aromatic compounds without the addition of a catalyst. US4891126A, US4789455A, JP1983196292A, and JP1983018421A all disclose methods for preparing mesophase pitch from aromatic compounds such as naphthalene, anthracene, and phenanthrene, but all use hydrofluoric acid, boron fluoride complex catalysts (HF / BF3), or aluminum chloride (AlCl3) solid catalysts. HF / BF3 catalysts are highly corrosive, requiring high-quality equipment and strict safety standards. AlCl3 catalysts, on the other hand, present the problem of difficulty in separating the mesophase pitch products, resulting in a high ash content in the mesophase pitch. Summary of the Invention

[0004] One of the technical problems to be solved by the present invention is to provide a method for preparing mesophase pitch by using aromatic compounds as the main raw material and heavy aromatics as auxiliary raw materials to induce the condensation of aromatic compounds without using a catalyst, based on the existing technology.

[0005] The second technical problem to be solved by the present invention is to provide a reaction apparatus for preparing mesophase pitch.

[0006] The third technical problem to be solved by the present invention is to provide an intermediate phase pitch product prepared by the above method.

[0007] This invention provides a method for preparing mesophase asphalt, comprising: mixing a narrow fraction of catalytic cracking slurry with anthracene to obtain a mixed feedstock; subjecting the mixed feedstock to high-pressure thermal conversion at a pressure of 0.5-5 MPa; followed by atmospheric-pressure thermal conversion; removing non-asphalt components from the reaction product by solvent extraction; and separating the remaining material by vacuum distillation to obtain distillate oil and residual solvent, thereby obtaining mesophase asphalt; wherein the narrow fraction of catalytic cracking slurry has a distillation range of 400℃ to 490℃, and its distillation range width is 30℃-50℃.

[0008] The present invention also provides an apparatus for preparing mesophase pitch to implement the above-mentioned method, comprising a feed pump, a heating furnace, a high-pressure reactor, an atmospheric pressure reactor, an extraction tower and a vacuum distillation tower connected in sequence, wherein a throttling valve is provided between the high-pressure reactor and the atmospheric pressure reactor.

[0009] The mesophase asphalt product prepared by the above-described method for preparing mesophase asphalt.

[0010] The beneficial effects of the method and apparatus for preparing mesophase pitch provided by this invention are as follows:

[0011] The method provided by this invention uses anthracene compounded with catalytic cracking slurry, a byproduct of a catalytic cracking unit, as a raw material for producing mesophase pitch. The catalytic cracking slurry induces the condensation of the aromatic compound anthracene, and mesophase pitch with more uniform spherical size is prepared without the use of a catalyst, thus avoiding the problems caused by the use of a catalyst.

[0012] The apparatus provided by this invention is applicable to the above-described method for producing mesophase bitumen. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the process for preparing mesophase pitch provided by the present invention;

[0014] Wherein: 1-Raw material tank; 2-Feed pump; 3-Heating furnace; 4-High pressure reactor; 5-Throttle valve; 6-Atmospheric pressure reactor; 7-Extraction tower; 8-Throttle valve; 9-Vacuum distillation tower; 10-Extractant; 11-Non-asphaltite components; 12-Distillate oil; 13-Mesophase asphalt product.

[0015] Figure 2 This is a polarized light reflection photograph of the mesophase bitumen sample obtained in Example 1.

[0016] Figure 3 This is a polarized light reflection photograph of the mesophase bitumen sample obtained in Example 2.

[0017] Figure 4 This is a polarized light reflection photograph of the mesophase bitumen sample obtained in Comparative Example 1.

[0018] Figure 5 This is a polarized reflectance photograph of the mesophase bitumen sample obtained in Comparative Example 2. Detailed Implementation

[0019] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0020] In a first aspect, the present invention provides a method for preparing mesophase asphalt, comprising: mixing a narrow fraction of catalytic cracking slurry oil with anthracene to obtain a mixed feedstock; subjecting the mixed feedstock to high-pressure thermal conversion at a pressure of 0.5-5 MPa, preferably 3-5 MPa; and then subjecting it to atmospheric-pressure thermal conversion; removing non-asphalt components from the reaction product by solvent extraction; and separating the remaining material by vacuum distillation to obtain distillate oil and residual solvent, thereby obtaining mesophase asphalt; wherein the narrow fraction of catalytic cracking slurry oil has a distillation range of 400°C to 490°C, and its distillation range width is 30°C-50°C.

[0021] Optionally, after solid particles are removed from the catalytic cracking slurry from the catalytic cracking unit, it is contacted with a hydrotreating catalyst to undergo a hydrotreating reaction, and then cut into the narrow fraction of the catalytic cracking slurry before or after the hydrotreating reaction.

[0022] In the method provided by this invention, the feedstock for the high-pressure thermal conversion is a mixture of narrow fractions of catalytic cracking slurry and anthracene, an aromatic compound, in a certain proportion. The narrow fractions of catalytic cracking slurry are derived from catalytic cracking slurry, a byproduct of the catalytic cracking unit. After desolidification to remove catalyst powder, the solid content is reduced to below 20 mg / kg to obtain clarified catalytic cracking oil. The clarified catalytic cracking slurry contains certain heteroatoms such as sulfur, nitrogen, and oxygen. These atoms are detrimental to the formation and morphology of the mesophase. To further improve the quality of the mesophase asphalt, the clarified catalytic cracking slurry can optionally be hydrotreated to obtain hydrorefined catalytic slurry with a lower heteroatom content. This hydrorefined catalytic cracking slurry is then distilled and segmented to obtain narrow fractions of hydrorefined catalytic cracking slurry with a certain distillation range.

[0023] In the method provided by this invention, the hydrogenation catalyst is an active metal component supported on a heat-resistant inorganic oxide support, wherein the active metal is selected from one or more of Co, Ni, and Mo; the operating conditions for the hydrogenation reaction are: reaction temperature of 280-330℃, pressure of 2.5-4.0 MPa, and space velocity of 1.0-1.5 h⁻¹. -1 The hydrogen-to-oil volume ratio is 250-350 Nm. 3 / m 3.

[0024] In the method provided by this invention, the narrow fraction of catalytic cracking slurry refers to any fraction with a distillation range of 30℃-50℃, within the range of 400℃ to 490℃. For example, 400℃-430℃, 400℃-435℃, 400℃-440℃, 400℃-445℃, 400℃-450℃, 410℃-440℃, 420℃-450℃, 430℃-460℃, 440℃-470℃, 450℃-480℃, 460℃-490℃, and any two values ​​that satisfy the above conditions. Preferably, the narrow distillation range of the catalytic cracking slurry oil is 30°C; preferably, the narrow distillation range of the catalytic cracking slurry oil is 400-430°C, 430-460°C, or 460-490°C; more preferably, the narrow distillation range of the catalytic cracking slurry oil is 430-460°C.

[0025] In the method provided by the present invention, a narrow fraction of catalytic cracking slurry oil is mixed with anthracene at a mass ratio of 1:1-10 to obtain a mixed feedstock; preferably, the mass ratio of the narrow fraction of catalytic cracking slurry oil to anthracene is 1:1-5.

[0026] In the method provided by the present invention, the high-pressure thermal conversion is carried out in a closed self-pressurization manner; preferably, the reaction is carried out at 400-480°C for 2-24 hours; more preferably, the reaction is carried out at 430°C-450°C for 2-5 hours.

[0027] Preferably, the atmospheric pressure thermal conversion is carried out at atmospheric pressure and a temperature of 400-480℃ for 0.5-5 hours; more preferably, it is carried out at a temperature of 430℃-450℃ for 1-3 hours.

[0028] In the method provided by this invention, the solvent used for solvent extraction is selected from one or a mixture of several of n-heptane, toluene, tetrahydrofuran, and furfural;

[0029] Preferably, the solvent is n-heptane or a mixed solvent of n-heptane and toluene in a mass ratio of 7:3.

[0030] In the method provided by this invention, the cutting temperature of the vacuum distillation is converted to a boiling point temperature of 500-530℃ under normal pressure, the absolute pressure of the vacuum distillation operation is 0.2-0.3 mmHg, the oil temperature at the bottom of the column is 340-350℃, the temperature at the top of the column is 220-270℃, and mesophase pitch is obtained at the bottom of the column. More preferably, the cutting temperature is converted to 520℃.

[0031] The thermal conversion of this invention is divided into two stages. The first stage is a thermal conversion reaction under high pressure, preferably in a closed, self-pressurizing manner. The second stage is a thermal conversion reaction at atmospheric pressure. In the high-pressure thermal conversion stage, anthracene's boiling point at atmospheric pressure is only 345°C, requiring a certain pressure to maintain its carbonization reaction in the liquid phase. Furthermore, as the system temperature increases and the reaction proceeds, the narrow fraction of the catalytic cracking slurry will crack and release some small-molecule hydrocarbons during the thermal conversion process. These small-molecule hydrocarbons continuously generate free radicals during cracking, inducing condensation polymerization. To fully utilize the free radicals generated by these small-molecule hydrocarbons, it is necessary to maintain the pressure of the reaction system. Due to the higher system pressure, the small-molecule hydrocarbons generated by cracking will remain in the liquid phase, which helps reduce the viscosity of the liquid phase, dilute the concentration of anthracene, prevent excessive and rapid condensation of anthracene, and prevent local overheating and coking of the system. In the atmospheric pressure thermal conversion stage, the reaction proceeds in the later stages to allow the small-molecule hydrocarbons to quickly leave the reaction system and increase the concentration of the generated mesophase microspheres, facilitating their rapid growth and coalescence.

[0032] In the method provided by this invention, the reaction temperature for both the high-pressure thermal conversion and the atmospheric-pressure thermal conversion reaction is 400-480℃. Generally, low temperature and long residence time are beneficial to the growth of the mesophase molecular crystal structure, resulting in more uniform mesophase pitch balloons. However, considering production efficiency, this invention preferably uses a reaction temperature of 430℃-450℃.

[0033] In the method provided by this invention, solvent extraction is used to remove non-asphaltene components from the thermal conversion products. These non-asphaltene components are soluble in the extraction solvent and can be separated. Typically, the solvent used is one or a mixture of n-heptane, toluene, tetrahydrofuran, and furfural. Preferably, the solvent used is n-heptane or a mixture of n-heptane and toluene. Adding a certain amount of toluene to n-heptane can more effectively increase the content of the mesophase and increase the diameter of the mesophase microspheres; however, the proportion of toluene added should not be too high. A 7:3 ratio of n-heptane to toluene mixture is generally optimal.

[0034] In the method provided by this invention, vacuum distillation is used to remove distillate oil and residual solvent from solvent-insoluble matter, leaving mesophase pitch. The vacuum distillation operating temperature is 340-350℃ at the bottom of the column and 220-270℃ at the top of the column. The operating pressure is 0.2-0.3 mmHg absolute pressure. The calculated cut temperature at atmospheric pressure is 500-530℃. Generally speaking, the higher the cut temperature, the higher the mesophase content of the mesophase pitch.

[0035] Secondly, the present invention provides an apparatus for preparing mesophase pitch, comprising a feed pump, a heating furnace, a high-pressure reactor, an atmospheric-pressure reactor, an extraction tower, and a vacuum distillation tower connected in sequence, wherein a throttling valve is provided between the high-pressure reactor and the atmospheric-pressure reactor.

[0036] Appendix Figure 1 A schematic flow diagram of the apparatus for preparing mesophase pitch provided by the present invention is attached. Figure 1 As shown, the apparatus for preparing mesophase pitch includes a feed pump 2, a heating furnace 3, a high-pressure reactor 4, an atmospheric pressure reactor 6, an extraction tower 7, and a vacuum distillation tower 9 connected in sequence. A throttling valve 5 is provided between the high-pressure reactor 6 and the atmospheric pressure reactor 4.

[0037] The apparatus for preparing mesophase asphalt includes a feed tank 1, in which narrow fractions of catalytic cracking slurry and anthracene are mixed. The feed tank 1 is connected to a heating furnace 3 via a feed pump 2. After the mixed raw materials are heated in the heating furnace 3, they enter a high-pressure reactor 4 for high-pressure thermal conversion reaction. The stream after high-pressure thermal conversion enters an atmospheric pressure reactor 6 through a throttle valve 5, where thermal conversion reaction continues under atmospheric pressure. The stream after reaction enters an extraction tower 7. The extraction solvent 10 enters from the top of the extraction tower 7, and the extract is discharged from the middle of the extraction tower 7. After removing components that are easily soluble in the solvent, the extract enters a vacuum distillation tower 9. Distillate oil 12 is separated from the top of the tower, and mesophase asphalt product 13 is obtained from the bottom of the tower.

[0038] Thirdly, the present invention provides mesophase pitch products prepared by any of the above methods.

[0039] The present invention will be described in detail below through embodiments, but this does not limit the invention. Unless otherwise specified, the methods used in the embodiments and comparative examples are conventional methods in the art.

[0040] In the following examples and comparative examples, the hydrotreating catalyst was purchased from the Catalyst Division of China Petroleum & Chemical Corporation (Sinopec) and its brand name was CH-20.

[0041] The Yanshan catalytic cracking slurry is a byproduct of the wax oil catalytic cracking unit of the Yanshan Branch of China Petroleum & Chemical Corporation. The 400-430℃ narrow fraction of the Maoming catalytic cracking slurry is derived from the catalytic slurry of the heavy oil catalytic cracking unit of the Maoming Branch of China Petroleum & Chemical Corporation. The 400-430℃ narrow fraction is obtained by vacuum distillation. Its properties are shown in Table 1.

[0042] Analysis method:

[0043] The hydrocarbon composition of the feedstock oil was determined in accordance with the petrochemical industry standard "Determination of Hydrocarbons in Saturated Hydrocarbon Fractions of Gas Oil (Mass Spectrometry) (SH / T 0659-1998)".

[0044] The carbon, hydrogen, sulfur and nitrogen content of raw materials and products was determined in accordance with the petrochemical industry standard "Determination of carbon, hydrogen and nitrogen in petroleum products and lubricants by elemental analyzer method (SH / T 0656-2017)".

[0045] The method for determining the oxygen content of raw materials and products involves pyrolyzing the sample in a high-temperature pyrolysis tube containing carbon powder, during which oxygen-containing compounds are quantitatively converted into carbon monoxide. A carrier gas carries the pyrolysis products into a series of scrubbers to remove acid gases and water vapor. Finally, the samples are detected by an infrared detector.

[0046] The method for observing the mesophase morphology is as follows: First, 4-5g of mesophase pitch sample is embedded inside epoxy resin, and a curing agent, polyene polyamine, is added. After the epoxy resin cures, the surface of the embedded sample is metallographically polished. Finally, the polished surface is observed using a polarizing microscope. The mesophase component appears as a bright area under the polarizing microscope, while the non-mesophase component appears as a dark area. The percentage of the total image area occupied by the bright area is the mesophase content, which can be directly determined using Leica Microsystems' LAS image processing software.

[0047] The softening point of the asphalt was determined according to the Mettler method of ASTM D3104, "Determination of the Softening Point of Asphalt".

[0048] The yield is calculated as: (mass of mesophase pitch obtained / mass of raw material) × 100%.

[0049] Example 1

[0050] The Yanshan catalytic cracking slurry oil from Table 1 was first subjected to desolidification and filtration to remove catalyst powder, and then hydrotreated to obtain hydrorefined Yanshan catalytic cracking slurry oil. The hydrotreatment catalyst used was CH-20, and the operating conditions were: reaction temperature 290℃, reaction pressure 3.5MPa, and hydrogen-to-oil ratio 300Nm. 3 / m 3 The volumetric space velocity is 1.2 h⁻¹. -1 The hydrotreated Yanshan catalytic oil slurry was subjected to vacuum distillation to obtain a narrow fraction of hydrotreated Yanshan catalytic oil slurry at 400-430℃.

[0051] The feedstock was prepared by mixing the narrow fraction of Yanshan catalytic cracking slurry oil (400-430℃) which had been hydrotreated and refined with anthracene at a mass ratio of 1:3. 500g of the feedstock was reacted in a closed, self-pressurized reactor at 440℃ for 3 hours, followed by thermal conversion at atmospheric pressure and 440℃ for 2 hours. The thermal conversion product was then extracted with 1000g of a mixed solvent of n-heptane and toluene in a 7:3 ratio. Finally, the solvent-insoluble matter was separated by vacuum distillation to remove the residual solvent and the distillate oil with a boiling point below 520℃, yielding 171g of mesophase pitch with a yield of 34.2%. Its properties are listed in Table 2.

[0052] The polarized reflectance photographs of the obtained mesophase bitumen samples are attached. Figure 2 As shown, the intermediate phase content is 85%, from the attached Figure 2 It can be seen from the sample that the size of the mesophase spheres is relatively uniform.

[0053] Example 2

[0054] The feedstock was prepared by mixing the narrow fraction of the hydrotreated Yanshan catalytic cracking slurry oil (400-430℃) from Example 1 with anthracene at a mass ratio of 1:3. 500g of the feedstock was reacted in a closed, self-pressurized reactor at 430℃ for 3.5 hours, followed by thermal conversion at atmospheric pressure and 430℃ for 2.5 hours. The thermal conversion product was then extracted using 1000g of n-heptane solvent. Finally, the solvent-insoluble matter was separated by vacuum distillation to remove the residual solvent and distillate oil with a boiling point below 520℃, yielding 164g of mesophase pitch with a yield of 34.2%. Its properties are listed in Table 2. A polarized reflectance photograph of the obtained mesophase pitch sample is attached. Figure 3 As shown, the intermediate phase content is 56%, from the attached Figure 3 It can be seen from the sample that the size of the mesophase spheres is relatively uniform.

[0055] Example 3

[0056] Example 3 illustrates the reaction using catalytic slurry that has not undergone hydrorefining.

[0057] The narrow fraction of Maoming catalytic cracking slurry oil at 400-430℃ was first desolidified and filtered to remove catalyst powder, and then subjected to vacuum distillation to obtain the narrow fraction of Maoming catalytic cracking slurry oil at 400-430℃, the properties of which are shown in Table 1.

[0058] The feedstock was prepared by mixing a narrow fraction of catalytic cracking oil slurry (400-430℃) with anthracene (an aromatic compound) at a mass ratio of 1:3. The feedstock was then subjected to a closed, self-pressurized reaction at 450℃ for 2 hours, followed by atmospheric pressure thermal conversion at 430℃ for another 2 hours. The thermal conversion product was then extracted using 1000g of a 7:3 mixture of n-heptane and toluene as a solvent, yielding 176g of mesophase pitch (35.2%). Its properties are listed in Table 2. A polarized reflectance photograph of the obtained mesophase pitch sample is attached. Figure 4 As shown, the intermediate phase content is 85%, from the attached Figure 4 It can be seen that the intermediate phase of the sample is mainly mosaic-shaped, with a small number of small spheres of varying sizes.

[0059] Comparative Example 1

[0060] This comparative example uses existing methods for producing mesophase pitch, without adding anthracene to the feedstock, and employs a single thermal conversion without extraction separation.

[0061] The narrow fraction of Yanshan catalytic oil slurry at 400-430℃ after hydrorefining was used in Example 1.

[0062] Using 500g of hydrotreated catalytic cracking slurry with a narrow fraction at 400-430℃ as feedstock, the feedstock was reacted at a constant temperature of 440℃ under normal pressure for 5 hours in a reactor; then, the distillate oil with a boiling point less than 520℃ was separated by vacuum distillation to obtain 130g of mesophase asphalt with a yield of 26.0%, the properties of which are listed in Table 2.

[0063] The polarized reflectance photographs of the obtained mesophase bitumen samples are attached. Figure 5 As shown, the content of the intermediate phase is 43%, from the attached Figure 5 It can be seen from the sample that the size of the mesophase spheres is relatively uniform.

[0064] Table 1

[0065]

[0066] Table 2

Claims

1. A method for preparing mesophase pitch, characterized in that, include: The narrow fraction of catalytic cracking slurry is mixed with anthracene to obtain a mixed feedstock. The mixed feedstock is subjected to high-pressure thermal conversion at a pressure of 0.5-5 MPa and a reaction temperature of 400-480℃ for 2-24 hours. Then, it is subjected to atmospheric pressure thermal conversion at a temperature of 400-480℃ for 0.5-5 hours. The reaction product is solvent-extracted to remove non-asphalt components. The remaining material is separated into distillate oil and residual solvent by vacuum distillation to obtain mesophase asphalt. The narrow fraction of catalytic cracking slurry has a distillation range of 400℃ to 490℃ and a distillation range width of 30℃-50℃.

2. The method for preparing mesophase pitch according to claim 1, characterized in that, Catalytic cracking slurry from the catalytic cracking unit is contacted with a hydrotreating catalyst to undergo a hydrotreating reaction, and is then cut into narrow fractions of the catalytic cracking slurry before or after the hydrotreating reaction.

3. The method for preparing mesophase pitch according to claim 2, characterized in that, The hydrogenation catalyst is composed of an active metal component supported on a heat-resistant inorganic oxide support, wherein the active metal is selected from one or more of Co, Ni, and Mo. The operating conditions for the hydrogenation reaction are as follows: reaction temperature 280-330℃, pressure 2.5-4.0 MPa, and space velocity 1.0-1.5 h⁻¹. -1 The hydrogen-to-oil volume ratio is 250-350 Nm. 3 / m 3 .

4. The method for preparing mesophase pitch according to claim 1, 2 or 3, characterized in that, The narrow distillation range of the catalytic cracking slurry is 30°C.

5. The method for preparing mesophase pitch according to claim 4, characterized in that, The narrow distillation range of the catalytic cracking slurry oil is 400-430℃, 430-460℃, or 460-490℃.

6. The method for preparing mesophase pitch according to claim 5, characterized in that, The narrow fraction of the catalytic cracking oil slurry has a distillation range of 430-460℃.

7. The method for preparing mesophase pitch according to claim 4, characterized in that, The narrow fraction of catalytic cracking oil slurry is mixed with anthracene at a mass ratio of 1:1-10 to obtain a mixed feedstock.

8. The method for preparing mesophase pitch according to claim 7, characterized in that, The mass ratio of the narrow fraction of the catalytic cracking slurry to anthracene is 1:1-5.

9. The method for preparing mesophase pitch according to any one of claims 1-3 and 5-8, characterized in that, The high-pressure thermal conversion is carried out in a closed, self-pressurized manner, at a temperature of 430℃-450℃ for 2-5 hours.

10. The method for preparing mesophase pitch according to any one of claims 1-3 and 5-8, characterized in that, The atmospheric pressure thermal conversion is carried out at a temperature of 430℃-450℃ for 1-3 hours.

11. The method for preparing mesophase pitch according to any one of claims 1-3 and 5-8, characterized in that, The solvent used in the solvent extraction is selected from one or a mixture of several of n-heptane, toluene, tetrahydrofuran, and furfural.

12. The method for preparing mesophase pitch according to claim 11, characterized in that, The solvent is n-heptane or a mixture of n-heptane and toluene in a mass ratio of 7:

3.

13. The method for preparing mesophase pitch according to any one of claims 1-3 and 5-8, characterized in that, The cutting temperature of the vacuum distillation is 500-530℃, the operating absolute pressure is 0.2-0.3 mmHg, the bottom oil temperature is 340-350℃, the top temperature is 220-270℃, and the bottom of the column yields mesophase pitch.

14. The method for preparing mesophase pitch according to claim 13, characterized in that, The cutting temperature is 520℃.

15. A reaction apparatus for preparing mesophase pitch, characterized in that, The method for preparing mesophase pitch according to any one of claims 1-14 includes a feed pump, a heating furnace, a high-pressure reactor, an atmospheric-pressure reactor, an extraction tower, and a vacuum distillation tower connected in sequence, wherein a throttling valve is provided between the high-pressure reactor and the atmospheric-pressure reactor.

16. The mesophase pitch product prepared by the method for preparing mesophase pitch according to any one of claims 1-14.

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