Process for preparing super-conductive carbon black by refining and separating catalytic slurry oil

Abstract

This invention relates to the field of heavy oil processing and carbon material preparation technology, and discloses a process for preparing superconducting carbon black from the refining and separation of catalytic oil slurry. The process sequentially includes a refining unit, a conversion unit, and a post-treatment unit. In the refining unit, the catalytic oil slurry is subjected to electric field-coordinated centrifugation and ultrasonic-enhanced solvent extraction to remove solid impurities and enrich polycyclic aromatic hydrocarbons. In the conversion unit, the extract is subjected to catalytic condensation to generate mesophase pitch, template-guided carbonization to construct an ordered mesoporous framework, and plasma graphitization to improve crystallinity. The post-treatment unit performs graded purification and surface modification on the obtained carbon material, ultimately obtaining superconducting carbon black with a three-dimensional interconnected conductive network. This invention achieves high-value-added resource utilization of catalytic oil slurry, has a high degree of process integration, and produces carbon black products with excellent conductivity.

Description

Technical Field

[0001] This invention relates to the field of heavy oil processing and carbon material preparation technology, specifically a process for refining and separating catalytic oil slurry to prepare superconducting carbon black. Background Technology

[0002] Catalytic cracking is a key secondary processing technology in petroleum refining that converts heavy oil into light fuels. In addition to producing target products such as gasoline and diesel, this process also generates a certain amount of catalytic cracking slurry as a byproduct. Catalytic slurry is a complex heavy fraction rich in polycyclic aromatic hydrocarbons and gums, and also contains a large amount of solid catalyst powder. Due to its complex composition, high viscosity, and high content of solid impurities, its efficient utilization has traditionally been limited, typically used as a low-value fuel oil component or coking feedstock, resulting in low economic benefits and failing to achieve high-value-added utilization.

[0003] Carbon black is an important industrial carbon material, traditionally produced mainly through the incomplete combustion of hydrocarbons (such as the furnace process and acetylene process), and is widely used in rubber reinforcement, plastic coloring, and conductive fillers. Conductive carbon black, in particular, is in high demand for lithium-ion battery electrodes, antistatic materials, conductive coatings, and electromagnetic shielding materials due to its unique conductivity. However, the conductivity of traditional conductive carbon black, especially its conductivity and network-building ability under high-performance requirements, still has room for improvement. The preparation of superconducting carbon black with highly graphitized structures and controllable morphologies (such as three-dimensional interconnects) is currently a research hotspot, as these materials can significantly improve the conductivity threshold and overall performance of composite materials.

[0004] Currently, exploring the preparation of high-end carbon materials (such as needle coke, mesophase carbon microspheres, and carbon fibers) using heavy aromatic oils (such as coal tar pitch and catalytic slurry) as precursors through steps such as modification, polycondensation, carbonization, and graphitization has become an important research direction. Polycyclic aromatic hydrocarbon molecules in catalytic slurry are considered ideal precursors for constructing high-quality carbon materials. However, directly utilizing catalytic slurry faces significant challenges: First, the large amount of micron and submicron-sized catalyst powder (mainly composed of aluminosilicates) remaining in the slurry is difficult to completely remove. These solid impurities severely affect the purity and structural regularity of the carbon material during subsequent high-temperature processing, leading to increased defects and decreased electrical conductivity. Second, in addition to the ideal precursor aromatic hydrocarbons, the slurry also contains a large amount of non-ideal components such as saturated hydrocarbons, gums, and asphaltenes. These components interfere with the orderly stacking of aromatic molecules and the formation of the liquid crystal phase (mesophase), making it difficult to obtain highly ordered carbon intermediates. Existing pretreatment methods, such as simple sedimentation, centrifugation, or filtration, have limited effectiveness in separating ultrafine particles and colloidal components; while conventional solvent extraction can separate some components, it is inefficient and difficult to achieve high selective enrichment of aromatic components. Summary of the Invention

[0005] The purpose of this invention is to provide a process for the refining and separation of catalytic oil slurry to prepare superconducting carbon black, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides a process for the refining and separation of catalytic oil slurry to prepare superconducting carbon black, the process comprising a refining unit, a conversion unit, and a post-treatment unit executed sequentially:

[0007] The refining unit first performs electric field-coordinated centrifugal separation on the catalytic oil slurry. During the separation process, a DC electric field of 1000-5000V / cm is continuously applied, and the centrifugal force field is 2000-6000G, simultaneously removing catalyst particles with a particle size greater than 1 micrometer. The separated slurry enters an ultrasonically enhanced solvent extraction tower, where it is countercurrently contacted with a composite solvent under the action of an ultrasonic field with a frequency of 20-40kHz. The composite solvent is a mixture of sulfolane and acetophenone in a mass ratio of 2:1 to 4:1, and the operating temperature is maintained at 70-95℃.

[0008] The conversion unit receives the extract rich in polycyclic aromatic hydrocarbons from the purification unit and sequentially performs three core reactions: catalytic polycondensation, template-guided carbonization, and plasma graphitization.

[0009] The post-processing unit performs graded purification and surface modification on the carbon material produced by the conversion unit, ultimately obtaining superconducting carbon black with a three-dimensional interconnected conductive network.

[0010] Preferably, the specific steps of the electric field-coordinated centrifugal separation are as follows:

[0011] The catalytic slurry, preheated to 90-110℃, is introduced into a centrifugal drum with coaxial cylindrical electrodes. The outer cylinder wall is connected to the positive terminal of a DC high-voltage power supply, and the central shaft is connected to the negative terminal.

[0012] Start the centrifuge and rotate it to 3000-5000 rpm to create a centrifugal force field. At the same time, turn on the high voltage power supply to stabilize the electric field strength at 3000V / cm. Under the action of the centrifugal force field, the charged solid particles migrate toward the electrode plates and are captured by the rotating wall. The processing time is 25-40 minutes.

[0013] Preferably, the specific steps of the ultrasound-enhanced solvent extraction are as follows:

[0014] The clarified liquid after electric field centrifugation is fed from the middle of the extraction tower, and the composite solvent is fed from the top of the tower, controlling the volume ratio of solvent to oil slurry to be 1.5:1 to 2.5:1;

[0015] The ultrasonic transducer array installed inside the tower generates a cavitation effect, which enhances mass transfer.

[0016] The aromatic-rich extract phase is collected from the bottom of the column, and the raffinate phase is collected from the top of the column; the operating temperature inside the column is 85℃, the ultrasonic power density is 50-100W / L, and the residence time is 45-75 minutes.

[0017] Preferably, the catalytic polycondensation step is implemented as follows:

[0018] The extract phase was flash-evaporated under a negative pressure of 0.095-0.099 MPa to remove most of the solvent, yielding a concentrate.

[0019] Add 1%-3% by mass of the metal phthalocyanine catalyst to the concentrate and place it in a high-pressure reactor equipped with a magnetic stirrer and a reflux condenser.

[0020] After replacing the air three times with high-purity nitrogen, the temperature is increased to 390-410℃ at a rate of 2℃ / min, and the pressure naturally rises to 1.5-2.5MPa. Under these conditions, the reaction is kept at a constant temperature for 3-5 hours to induce the directional condensation of aromatic molecules to form anisotropic mesophase spheres.

[0021] Preferably, the metal phthalocyanine catalyst is iron phthalocyanine or cobalt phthalocyanine, which is pre-loaded on a porous silica support with a loading of 10%-15%. After the reaction, the product is cooled to room temperature, and unreacted components and catalyst are removed by toluene extraction to obtain refined mesophase pitch with a softening point between 260-280℃ and an anisotropy content greater than 95%.

[0022] Preferably, the template-guided carbonization step is implemented as follows: the refined mesophase pitch is dissolved in tetrahydrofuran to prepare a 10% mass concentration solution; the nanoporous magnesium oxide template is immersed in the solution, and the solution is filled into the template pores by vacuum impregnation; after removal, it is dried at 60°C for 24 hours, and then heated to 900°C at 5°C / min under argon protection for 2 hours; after carbonization, the magnesium oxide template is dissolved and removed with dilute hydrochloric acid to obtain a primary carbon black skeleton with an ordered mesoporous structure.

[0023] Preferably, the plasma graphitization step is implemented as follows: a primary carbon black framework is placed on a graphite substrate in a microwave plasma chemical vapor deposition furnace, and the system is evacuated to 10... -2 After Pa, a mixture of argon and methane is introduced, with methane accounting for 5%-10% of the volume; the microwave source is turned on to generate plasma at a temperature of 2000-2500℃, and the processing time is 15-30 minutes.

[0024] Preferably, the specific steps of the fractional purification are as follows:

[0025] The plasma-treated carbon material was placed in a 1 mol / L hydrofluoric acid solution and washed at 50°C for 4 hours to remove residual silicon-based impurities.

[0026] Wash with deionized water until neutral; then disperse the material in ethanol, perform high-speed centrifugation and fractionation, and collect fractions with equivalent particle sizes of 50-200 nm corresponding to the sedimentation rate.

[0027] Preferably, the specific steps of the surface modification are as follows: the graded carbon material is dispersed in a mixed acid of concentrated nitric acid and concentrated sulfuric acid in a volume ratio of 1:3, and refluxed at 70°C for 2 hours to introduce carboxyl and hydroxyl oxygen-containing functional groups; after washing and drying, the treated material is annealed at 500°C for 1 hour by introducing ammonia gas into a tube furnace to achieve nitrogen doping of some functional groups, thereby optimizing its surface electronic state.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] The process described in this invention is designed to address the characteristics of catalytic oil slurry and the performance requirements of superconducting carbon black, providing an integrated refining, conversion, and post-treatment flow. This process first utilizes electric field-assisted centrifugal separation technology, where centrifugal force and a DC electric field couple to achieve highly efficient removal of micron-sized catalyst particles from the oil slurry. The electric field charges the fine particles, causing them to migrate along the electric field direction, enhancing the centrifugal separation's capture efficiency for fine particles and overcoming the shortcomings of traditional centrifugal separation in incomplete removal of submicron particles. This provides a raw material foundation with extremely low impurity content for subsequent steps.

[0030] The subsequent ultrasonic-enhanced solvent extraction utilized the cavitation effect generated by specific frequency ultrasound to violently disturb the liquid-liquid interface at the microscale, significantly increasing the mass transfer area and reducing mass transfer resistance. The selected sulfolane and acetophenone composite solvent system exhibited excellent selective solubility for polycyclic aromatic hydrocarbons in the catalytic slurry. The introduction of the ultrasonic field greatly accelerated the extraction rate, shortened the time required to reach equilibrium, improved processing efficiency, and achieved efficient enrichment and purification of aromatic components at a mild operating temperature, effectively removing components such as saturated hydrocarbons that interfere with subsequent polycondensation reactions.

[0031] In the conversion unit, the process transforms the aromatic hydrocarbon-rich extract through three steps: catalytic condensation, template-guided carbonization, and plasma graphitization. In the catalytic condensation step, under the action of a metal phthalocyanine catalyst and specific temperature and pressure conditions, aromatic hydrocarbon molecules undergo directional condensation to form mesophase microspheres with high anisotropy content. This mesophase is a key precursor for generating a highly ordered carbon structure. The subsequent template-guided carbonization utilizes the spatial confinement effect of a nanoporous magnesium oxide template, allowing the mesophase pitch to replicate the ordered pore structure of the template during carbonization, thereby directly constructing a primary carbon framework with a rudimentary three-dimensional interconnected network. This method achieves active design and precise control of the carbon black nanostructure. Finally, the plasma graphitization step, with the extremely high energy provided by high-temperature plasma, induces structural rearrangement of the primary carbon framework in a very short time, significantly improving the graphitization degree of the carbon material and enhancing its intrinsic conductivity. These three interconnected reactions gradually transform the molecular precursor into a carbon material with an ideal microstructure and high conductivity potential.

[0032] The post-processing unit's fractional purification operation, through acid washing and centrifugal classification, further removes any trace inorganic impurities that may remain, and screens out carbon black fractions with uniform particle size distribution, ensuring batch-to-batch consistency and performance stability. The surface modification step introduces oxygen- and nitrogen-containing functional groups onto the carbon black surface through mixed acid oxidation and ammonia heat treatment. This chemical modification not only improves the dispersibility of carbon black in polymer matrices and other media, preventing performance degradation due to agglomeration, but more importantly, the surface functional groups, especially nitrogen doping, can regulate the electronic state of the carbon material surface, potentially forming more efficient charge transport channels between carbon particles or between carbon particles and the matrix, thereby further enhancing its macroscopic conductivity. Attached Figure Description

[0033] Figure 1 This diagram illustrates the working steps of a process for preparing superconducting carbon black from a catalytic oil slurry, as described in this invention. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to specific embodiments and comparative examples. The following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

[0035] The specifications of the raw materials used in this embodiment and comparative example are as follows: the catalytic slurry was taken from a catalytic cracking unit of a petrochemical enterprise, with a density of 1.02-1.05 g / cm³, a carbon residue of 18-22 wt%, a catalyst particle content (mainly molecular sieve) of 3.5-4.2 wt%, and a polycyclic aromatic hydrocarbon content of 45-50 wt%; sulfolane, acetophenone, tetrahydrofuran, toluene, concentrated nitric acid, concentrated sulfuric acid, hydrofluoric acid, and dilute hydrochloric acid were all analytical grade and purchased from Sinopharm Chemical Reagent Co., Ltd.; iron phthalocyanine and cobalt phthalocyanine were industrial grade with a purity ≥98%; the porous silica support (specific surface area of ​​300-400 m² / g, pore size of 20-50 nm) and the nanoporous magnesium oxide template (specific surface area of ​​500-600 m² / g, pore size of 10-30 nm) were custom-made products; high-purity nitrogen, argon, and methane were all industrial gases with a purity ≥99.999%.

[0036] The equipment used in this embodiment and comparative example is as follows: Electric field-coordinated centrifugal separation equipment (customized, equipped with coaxial cylindrical electrodes, DC high voltage power supply output range 0-10000V / cm, centrifuge speed range 0-8000rpm); Ultrasonic enhanced solvent extraction tower (specifications φ50×1000mm, equipped with ultrasonic transducer array, frequency adjustable range 20-80kHz, power density adjustable range 0-200W / L); High-pressure reactor (volume 5L, equipped with magnetic stirring, reflux condensation and programmed temperature rise device, pressure measurement range 0-10MPa); Vacuum drying oven (temperature accuracy ±1℃, vacuum degree up to -0.098MPa); Tube furnace (equipped with argon and ammonia protection system, heating rate adjustable range 1-10℃ / min, maximum operating temperature 1200℃); Microwave plasma chemical vapor deposition furnace (microwave power 0-3kW, vacuum degree up to 10... -3 Pa, plasma temperature measurement range 0-3000℃; high-speed centrifuge (speed range 0-20000rpm, centrifugal force field range 0-25000G); laser particle size analyzer (test range 0.1-1000nm); four-probe resistance meter (accuracy ±0.01Ω·cm); transmission electron microscope (TEM, resolution 0.1nm); X-ray photoelectron spectroscopy (XPS, detection range 0-1000eV); specific surface area and porosity analyzer (BET, test range 0.01m² / g-10000m² / g).

[0037] The product performance evaluation indicators and test methods in this embodiment and comparative example are as follows:

[0038] Catalyst particle removal rate: determined by gravimetric method. The catalytic oil slurry before and after treatment was filtered and dried to constant weight, and the mass change of the residue (catalyst particles) after filtration was calculated. The formula is: Catalyst particle removal rate = (mass of catalyst particles before treatment - mass of catalyst particles after treatment) / mass of catalyst particles before treatment × 100%.

[0039] Extraction rate of polycyclic aromatic hydrocarbons (PAHs): The content of PAHs in the oil slurry before and after treatment was determined by high performance liquid chromatography (HPLC). The formula is: PAH extraction rate = (mass of PAHs in the extract - mass of PAHs in the raw oil slurry × proportion of raffinate) / mass of PAHs in the raw oil slurry × 100%.

[0040] Volume resistivity: The volume resistivity was measured using a four-probe resistance tester. The superconducting carbon black and epoxy resin were mixed evenly at a mass ratio of 1:10, pressed into a circular sample with a diameter of 10 mm and a thickness of 2 mm, and the volume resistivity was measured at room temperature. The average value of 5 test results was taken.

[0041] Particle size distribution: The particle size distribution was determined using a laser particle size analyzer. The superconducting carbon black was dispersed in ethanol and ultrasonically dispersed for 30 minutes before testing. The percentage of particles with an equivalent particle size of 50-200 nm was recorded.

[0042] Specific surface area: determined by the BET method, using nitrogen as the adsorbate, adsorption-desorption experiments were conducted at liquid nitrogen temperature (-196℃) to calculate the specific surface area of ​​the sample.

[0043] Anisotropy content: The mesophase asphalt sample was prepared into a thin section and observed under a polarizing microscope. The area ratio of the anisotropic region was taken as the average value of 5 fields of view.

[0044] Nitrogen doping: The photoelectron spectral peaks of the N1s orbital on the sample surface were analyzed using XPS to calculate the atomic percentage of nitrogen.

[0045] Microstructure: TEM was used to observe the morphology and three-dimensional interconnected conductive network structure of superconducting carbon black dispersed in ethanol and dropped onto a copper grid.

[0046] Example 1

[0047] See appendix Figure 1 This embodiment provides a process for the refining and separation of catalytic oil slurry to prepare superconducting carbon black, the specific steps of which are as follows:

[0048] 1. Refining unit processing

[0049] 1.1 Electric field-coordinated centrifugal separation

[0050] Take 10 kg of catalytic oil slurry and preheat it to 100°C in a preheating tank. Then, introduce it into a centrifugal drum with coaxial cylindrical electrodes in an electric field-coordinated centrifugal separation device. The outer cylinder wall is connected to the positive terminal of a DC high-voltage power supply, and the central shaft is connected to the negative terminal. Start the centrifuge and adjust the speed to 4000 rpm to form a centrifugal force field of 4500G. At the same time, turn on the high-voltage power supply and adjust the electric field strength to 3000V / cm. Maintain this state for 30 minutes. After treatment, collect the clear liquid in the centrifugal drum. The catalyst particle removal rate is determined by gravimetric method, and the result is 99.2%. Laser particle size analyzer test shows that particles with a diameter greater than 1 micrometer in the clear liquid are completely removed.

[0051] 1.2 Ultrasonic Enhanced Solvent Extraction

[0052] The clarified liquid obtained in step 1.1 was fed into the middle of the ultrasonic-enhanced solvent extraction tower at a feed rate of 2 L / h. Simultaneously, a composite solvent was prepared, consisting of sulfolane and acetophenone mixed at a mass ratio of 3:1. This composite solvent was fed into the top of the extraction tower at a feed rate of 3 L / h, maintaining a solvent-to-oil slurry volume ratio of 1.5:1. The ultrasonic transducer array in the extraction tower was activated, the ultrasonic frequency was adjusted to 30 kHz, the ultrasonic power density was set to 80 W / L, the operating temperature inside the tower was maintained at 85 °C, and the residence time of the material in the tower was controlled to 60 minutes. Under the effect of ultrasonic cavitation, the clarified liquid and the composite solvent underwent sufficient countercurrent contact and mass transfer. The extract phase rich in polycyclic aromatic hydrocarbons (PAHs) was collected from the bottom of the tower, and the raffinate phase was collected from the top. The PAH extraction rate was determined by HPLC, and the result was 92.5%.

[0053] 2. Conversion Unit Processing

[0054] 2.1 Catalytic Polycondensation

[0055] The extract phase obtained in step 1.2 was introduced into a flash evaporator and flashed at 120°C under a negative pressure of 0.097 MPa to remove most of the solvent, yielding 3.8 kg of concentrate. 2% (by mass) of iron phthalocyanine catalyst (pre-loaded on a porous silica support with a loading of 12%) was added to the concentrate, and after thorough mixing, it was placed in a 5 L high-pressure reactor equipped with a magnetic stirrer and a reflux condenser. The reactor was closed, and the air inside was purged three times with high-purity nitrogen for 10 minutes each time to ensure no oxygen remained. The magnetic stirrer was then turned on (300 rpm), and the temperature was programmed to rise to 400°C at a rate of 2°C / min. At this point, the pressure inside the reactor naturally increased to 2.0 MPa. The reaction was maintained at this temperature and pressure for 4 hours to induce the directional condensation of aromatic molecules into anisotropic mesophase spheres. After the reaction was completed, the product was cooled to room temperature, filtered to remove the catalyst support, and then subjected to Soxhlet extraction with toluene for 24 hours to remove unreacted components and residual catalyst, yielding 2.9 kg of refined mesophase pitch. The softening point of the mesophase pitch was tested to be 270℃, and the anisotropy content was 96.3%.

[0056] 2.2 Template-guided carbonization

[0057] Take 2 kg of refined mesophase pitch and dissolve it in 18 kg of tetrahydrofuran, stirring until completely dissolved to prepare a 10% (w / w) solution. Immerse 1.5 kg of nanoporous magnesium oxide template in this solution and place it in a vacuum drying oven. Immerse it for 2 hours under a vacuum of -0.095 MPa to ensure the solution fully fills the template pores. Remove the impregnated template and vacuum dry it at 60 °C for 24 hours to remove the tetrahydrofuran solvent. Place the dried template in a tube furnace, introduce argon as a protective gas at a flow rate of 500 mL / min, and heat it to 900 °C at a rate of 5 °C / min. Carbonize at this temperature for 2 hours. After carbonization, allow it to cool naturally to room temperature. Immerse the product in dilute hydrochloric acid (10% (w / w)) and stir at 60 °C for 4 hours to dissolve and remove the magnesium oxide template. Filter and wash until neutral to obtain 1.2 kg of primary carbon black framework with an ordered mesoporous structure.

[0058] 2.3 Plasma graphitization

[0059] The primary carbon black skeleton obtained in step 2.2 was placed on the graphite base of the microwave plasma chemical vapor deposition furnace. The furnace was then closed, and the system was evacuated to 10 °C. -2 Pa. Then, a mixture of argon and methane, with methane comprising 8% by volume, is introduced at a total flow rate of 300 mL / min to maintain a stable furnace pressure of 10. -1Pa. The microwave source was turned on, and the microwave power was adjusted to 2kW to generate plasma at a temperature of 2200℃. This plasma was used to perform graphitization treatment on the primary carbon black framework for 20 minutes. During the treatment, carbon atoms generated from methane cracking were deposited on the surface and within the pores of the primary carbon black framework. Simultaneously, the high temperature of the plasma enhanced the graphitization degree of the carbon material, forming a highly conductive carbon structure.

[0060] 3. Post-processing unit processing

[0061] 3.1 Fractional purification

[0062] The plasma-treated carbon material from step 2.3 was placed in a 1 mol / L hydrofluoric acid solution and washed with shaking at 50°C for 4 hours at a shaking rate of 200 rpm to remove any remaining silicon-based impurities (from the catalyst support). After washing, the carbon material was repeatedly rinsed with deionized water until the solution pH reached 7 (neutral), and then filtered to collect the carbon material. The carbon material was dispersed in 5 L of ethanol and ultrasonically dispersed for 30 minutes. Subsequently, it was placed in a high-speed centrifuge at 12000 rpm for high-speed centrifugation and fractionation. Fractions with equivalent particle sizes of 50-200 nm were collected according to the sedimentation rate, filtered, and dried to obtain 0.95 kg of purified carbon black.

[0063] 3.2 Surface finishing

[0064] The fractionated carbon material from step 3.1 was dispersed in a mixed acid solution of concentrated nitric acid and concentrated sulfuric acid at a volume ratio of 1:3 (solid-liquid ratio 1:20, g:mL). The mixture was refluxed at 70°C for 2 hours with a stirring rate of 150 rpm to introduce oxygen-containing functional groups such as carboxyl and hydroxyl groups onto the carbon material surface. After treatment, the carbon material was washed with deionized water until neutral, filtered, and vacuum-dried at 120°C for 12 hours. The dried carbon material was then placed in a tube furnace, and ammonia gas was introduced as the reaction gas at a flow rate of 400 mL / min. The temperature was increased to 500°C at a rate of 5°C / min and annealed at this temperature for 1 hour to achieve nitrogen doping of some functional groups and optimize its surface electronic state. After annealing, the carbon material was naturally cooled to room temperature to obtain 0.9 kg of superconducting carbon black.

[0065] The performance of the superconducting carbon black prepared in this embodiment was tested, and the test results are shown in Table 1.

[0066] Example 2

[0067] This embodiment provides a process for the purification and separation of catalytic oil slurry to prepare superconducting carbon black, the specific steps of which are as follows:

[0068] 1. Refining unit processing

[0069] 1.1 Electric field-coordinated centrifugal separation

[0070] Take 10 kg of catalytic oil slurry and preheat it to 95°C in a preheating tank. Then, introduce it into a centrifugal drum with coaxial cylindrical electrodes in an electric field-coordinated centrifugal separation device. Connect the outer cylinder wall to the positive terminal of a DC high-voltage power supply and the central shaft to the negative terminal. Start the centrifuge and adjust the speed to 3500 rpm to form a centrifugal force field of 3800 G. Simultaneously, turn on the high-voltage power supply and adjust the electric field strength to 2500 V / cm. Maintain this state for 35 minutes. After treatment, collect the clear liquid in the centrifugal drum. The catalyst particle removal rate is measured to be 98.8%. Laser particle size analyzer testing shows that particles larger than 1 micrometer in diameter in the clear liquid are completely removed.

[0071] 1.2 Ultrasonic Enhanced Solvent Extraction

[0072] The clarified liquid obtained in step 1.1 was fed into the middle of the ultrasonic-enhanced solvent extraction tower at a feed rate of 2 L / h. A composite solvent was prepared by mixing sulfolane and acetophenone in a mass ratio of 4:1. This composite solvent was fed into the top of the extraction tower at a feed rate of 4 L / h, maintaining a solvent-to-oil slurry volume ratio of 2.0:1. The ultrasonic transducer array was turned on, the ultrasonic frequency was adjusted to 25 kHz, the ultrasonic power density was set to 70 W / L, the operating temperature inside the tower was maintained at 80 °C, and the residence time of the material in the tower was controlled at 70 minutes. The extract phase rich in polycyclic aromatic hydrocarbons was collected from the bottom of the tower, and the raffinate phase was collected from the top. The extraction rate of polycyclic aromatic hydrocarbons was determined by HPLC, and the result was 93.8%.

[0073] 2. Conversion Unit Processing

[0074] 2.1 Catalytic Polycondensation

[0075] The extract phase obtained in step 1.2 was introduced into a flash evaporator and flashed to remove most of the solvent under a negative pressure of 0.098 MPa at a flash temperature of 125 °C, yielding 3.9 kg of concentrate. 1.5% (by weight) of cobalt phthalocyanine catalyst (pre-loaded on a porous silica support, 10% loading) was added to the concentrate, and after thorough stirring, it was placed in a 5 L high-pressure reactor. The air inside the reactor was purged three times with high-purity nitrogen. Magnetic stirring was started (300 rpm), and the temperature was programmed to rise to 395 °C at a rate of 2 °C / min. The pressure inside the reactor naturally increased to 1.8 MPa, and the reaction was maintained at this temperature for 4.5 hours. After the reaction, the mixture was cooled to room temperature, the catalyst support was removed by filtration, and the mixture was extracted with toluene using a Soxhlet extractor for 24 hours to obtain 3.0 kg of refined mesophase pitch. The softening point of the mesophase pitch was tested to be 265 °C, and the anisotropy content was 95.8%.

[0076] 2.2 Template-guided carbonization

[0077] 2 kg of refined mesophase pitch was dissolved in 18 kg of tetrahydrofuran to prepare a 10% (w / w) solution. 1.6 kg of nanoporous magnesium oxide template was immersed in this solution under vacuum for 2.5 hours, then removed and vacuum dried at 60 °C for 24 hours. The dried template was placed in a tube furnace, and argon gas was introduced (flow rate 500 mL / min). The temperature was increased to 900 °C at a rate of 5 °C / min, and carbonized at this temperature for 2 hours. After carbonization, the template was cooled to room temperature, and the magnesium oxide template was dissolved and removed with dilute hydrochloric acid. The solution was filtered and washed until neutral to obtain 1.22 kg of primary carbon black framework.

[0078] 2.3 Plasma graphitization

[0079] The primary carbon black skeleton was placed on a graphite base in a microwave plasma chemical vapor deposition furnace, and the system was evacuated to 10... -2 A mixture of argon and methane (6% methane by volume) was introduced at a flow rate of 280 mL / min. The microwave source was turned on, and the microwave power was adjusted to 1.8 kW to generate plasma at a temperature of 2100 °C for 25 minutes.

[0080] 3. Post-processing unit processing

[0081] 3.1 Fractional purification

[0082] The plasma-treated carbon material was placed in a 1 mol / L hydrofluoric acid solution and washed with shaking at 50°C for 4 hours. It was then washed with deionized water until neutral and filtered to collect the carbon material. The carbon material was dispersed in 5 L of ethanol, ultrasonically dispersed for 30 minutes, and fractionated by high-speed centrifugation (12000 rpm). Fractions with equivalent particle sizes of 50-200 nm were collected and dried to obtain 0.96 kg of purified carbon black.

[0083] 3.2 Surface finishing

[0084] The graded carbon material was dispersed in a mixed acid solution of concentrated nitric acid and concentrated sulfuric acid at a volume ratio of 1:3 (solid-liquid ratio 1:20) and refluxed at 70°C for 2 hours. After washing to neutrality and drying, it was placed in a tube furnace, ammonia gas was introduced (flow rate 400 mL / min), and annealed at 500°C for 1 hour. After cooling, 0.91 kg of superconducting carbon black was obtained.

[0085] The performance of the superconducting carbon black prepared in this embodiment was tested, and the test results are shown in Table 1.

[0086] Example 3

[0087] This embodiment provides a process for the purification and separation of catalytic oil slurry to prepare superconducting carbon black, the specific steps of which are as follows:

[0088] 1. Refining unit processing

[0089] 1.1 Electric field-coordinated centrifugal separation

[0090] Take 10 kg of catalytic oil slurry and preheat it to 105°C in a preheating tank. Then, introduce it into the centrifugal drum of an electric field-coordinated centrifugal separator with coaxial cylindrical electrodes. Connect the outer wall of the drum to the positive terminal of a DC high-voltage power supply and the central shaft to the negative terminal. Start the centrifuge and adjust the speed to 4500 rpm to form a centrifugal force field of 5200 G. Simultaneously, turn on the high-voltage power supply and adjust the electric field strength to 3500 V / cm. Maintain this state for 28 minutes. After treatment, collect the clear liquid. The catalyst particle removal rate is measured to be 99.5%. Laser particle size analyzer testing shows that particles larger than 1 micrometer in diameter are completely removed from the clear liquid.

[0091] 1.2 Ultrasonic Enhanced Solvent Extraction

[0092] The clarified liquid obtained in step 1.1 was fed into the middle of the ultrasonic-enhanced solvent extraction tower at a feed rate of 2 L / h. A composite solvent was prepared by mixing sulfolane and acetophenone in a mass ratio of 2:1. This composite solvent was fed into the top of the tower at a feed rate of 5 L / h, maintaining a solvent-to-oil slurry volume ratio of 2.5:1. The ultrasonic transducer array was turned on, the ultrasonic frequency was adjusted to 35 kHz, the ultrasonic power density was set to 90 W / L, the operating temperature inside the tower was maintained at 90 °C, and the material residence time was controlled at 50 minutes. The extract phase rich in polycyclic aromatic hydrocarbons was collected from the bottom of the tower, and the raffinate phase was collected from the top. The extraction rate of polycyclic aromatic hydrocarbons was determined by HPLC, and the result was 94.2%.

[0093] 2. Conversion Unit Processing

[0094] 2.1 Catalytic Polycondensation

[0095] The extract phase obtained in step 1.2 was introduced into a flash evaporator and flashed to remove most of the solvent under a negative pressure of 0.096 MPa at a flash temperature of 130°C, yielding 4.0 kg of concentrate. 2.5% (by mass) of iron phthalocyanine catalyst (pre-loaded on a porous silica support at a loading of 15%) was added to the concentrate, and after thorough mixing, it was placed in a 5 L high-pressure reactor. The air inside the reactor was purged three times with high-purity nitrogen. Magnetic stirring was started (300 rpm), and the temperature was programmed to rise to 405°C at a rate of 2°C / min. The pressure inside the reactor naturally increased to 2.2 MPa, and the reaction was maintained at this temperature for 3.5 hours. After the reaction, the mixture was cooled to room temperature, the catalyst support was removed by filtration, and the mixture was extracted with toluene using a Soxhlet extractor for 24 hours to obtain 3.1 kg of refined mesophase pitch. The softening point of the mesophase pitch was tested to be 275°C, and the anisotropy content was 97.1%.

[0096] 2.2 Template-guided carbonization

[0097] 2 kg of refined mesophase pitch was dissolved in 18 kg of tetrahydrofuran to prepare a 10% (w / w) solution. 1.4 kg of nanoporous magnesium oxide template was immersed in this solution under vacuum for 1.5 hours, then removed and vacuum dried at 60 °C for 24 hours. The dried template was placed in a tube furnace, and argon gas was introduced (flow rate 500 mL / min). The temperature was increased to 900 °C at a rate of 5 °C / min, and carbonized at this temperature for 2 hours. After carbonization, the template was cooled to room temperature, and the magnesium oxide template was dissolved and removed with dilute hydrochloric acid. The solution was filtered and washed until neutral to obtain 1.23 kg of primary carbon black framework.

[0098] 2.3 Plasma graphitization

[0099] The primary carbon black skeleton was placed on a graphite base in a microwave plasma chemical vapor deposition furnace, and the system was evacuated to 10... -2 A mixture of argon and methane (9% methane by volume) was introduced at a flow rate of 320 mL / min. The microwave source was turned on, and the microwave power was adjusted to 2.2 kW to generate plasma at a temperature of 2300 °C. The processing time was 18 minutes.

[0100] 3. Post-processing unit processing

[0101] 3.1 Fractional purification

[0102] The plasma-treated carbon material was placed in a 1 mol / L hydrofluoric acid solution and washed with shaking at 50°C for 4 hours. It was then washed with deionized water until neutral and filtered to collect the carbon material. The carbon material was dispersed in 5 L of ethanol, ultrasonically dispersed for 30 minutes, and fractionated by high-speed centrifugation (12000 rpm). Fractions with equivalent particle sizes of 50-200 nm were collected and dried to obtain 0.97 kg of purified carbon black.

[0103] 3.2 Surface finishing

[0104] The graded carbon material was dispersed in a mixed acid solution of concentrated nitric acid and concentrated sulfuric acid at a volume ratio of 1:3 (solid-liquid ratio 1:20) and refluxed at 70°C for 2 hours. After washing to neutrality and drying, it was placed in a tube furnace, ammonia gas was introduced (flow rate 400 mL / min), and annealed at 500°C for 1 hour. After cooling, 0.92 kg of superconducting carbon black was obtained.

[0105] The performance of the superconducting carbon black prepared in this embodiment was tested, and the test results are shown in Table 1.

[0106] Comparative Example 1

[0107] This comparative example uses conventional centrifugal separation instead of electric field-assisted centrifugal separation. The other steps are basically the same as in Example 1. The specific steps are as follows:

[0108] 1. Refining unit processing

[0109] 1.1 Conventional centrifugal separation

[0110] Take 10 kg of catalytic oil slurry, preheat it to 100℃, and then introduce it into a regular centrifuge. Adjust the speed to 4000 rpm to form a centrifugal force field of 4500G, and continue the treatment for 30 minutes without applying a DC electric field. After the treatment, collect the clear liquid, and determine that the catalyst particle removal rate is 82.3%. Laser particle size analyzer test shows that the clear liquid still contains some catalyst particles with a particle size greater than 1 micrometer (content is about 0.12 wt%).

[0111] 1.2 Ultrasonic Enhanced Solvent Extraction

[0112] The procedure was the same as in Example 1, and the extraction rate of polycyclic aromatic hydrocarbons was determined to be 81.5%.

[0113] 2. Conversion Unit Processing

[0114] The steps were the same as in Example 1, and the softening point of the mesophase asphalt obtained was 255℃, with an anisotropy content of 88.6%.

[0115] 3. Post-processing unit processing

[0116] The steps were the same as in Example 1, and 0.78 kg of superconducting carbon black was obtained.

[0117] The performance of the superconducting carbon black prepared in this comparative example was tested, and the test results are shown in Table 1.

[0118] Comparative Example 2

[0119] This comparative example does not use plasma graphitization treatment, but only conventional high-temperature graphitization. The other steps are basically the same as in Example 1, and the specific steps are as follows:

[0120] 1. Refining unit processing

[0121] The steps were the same as in Example 1, with a catalyst particle removal rate of 99.1% and a polycyclic aromatic hydrocarbon extraction rate of 92.3%.

[0122] 2. Conversion Unit Processing

[0123] 2.1 Catalytic Polycondensation

[0124] The steps were the same as in Example 1, and the softening point of the mesophase asphalt obtained was 268°C, with an anisotropy content of 96.1%.

[0125] 2.2 Template-guided carbonization

[0126] The steps were the same as in Example 1, and 1.18 kg of primary carbon black skeleton was obtained.

[0127] 2.3 Conventional High-Temperature Graphitization

[0128] The primary carbon black skeleton was placed in a tube furnace, and argon gas (flow rate 500 mL / min) was introduced. The temperature was increased to 2200°C at a heating rate of 5°C / min, and graphitized at a constant temperature for 2 hours, replacing the plasma graphitization treatment in Example 1.

[0129] 3. Post-processing unit processing

[0130] The steps were the same as in Example 1, and 0.85 kg of superconducting carbon black was obtained.

[0131] The performance of the superconducting carbon black prepared in this comparative example was tested, and the test results are shown in Table 1.

[0132]

[0133] Table 1: Performance test results of superconducting carbon black prepared in Examples 1-3 and Comparative Examples 1-2

[0134] As can be seen from the test results in Table 1, the superconducting carbon black prepared in Examples 1-3 is superior to that in Comparative Examples 1-2 in all performance indicators, which fully demonstrates the superiority of the process of the present invention.

[0135] From the perspective of the purification unit's performance, Examples 1-3, employing electric field-assisted centrifugal separation technology, achieved catalyst particle removal rates exceeding 98.8%, with Example 3 exhibiting the highest removal rate at 99.5%. The extraction rates of polycyclic aromatic hydrocarbons (PAHs) all exceeded 92%, with Example 3 reaching 94.2%. In contrast, Comparative Example 1, using conventional centrifugal separation without an applied DC electric field, achieved a catalyst particle removal rate of only 82.3%, significantly lower than the examples. Furthermore, the residual catalyst particles negatively impacted subsequent solvent extraction, resulting in a PAH extraction rate of only 81.5%. This is because during electric field-assisted centrifugal separation, the DC electric field charges the catalyst particles. Under the synergistic effect of centrifugal force and electric field, the particles migrate towards the electrode and are efficiently captured by the rotating wall. Compared to a single centrifugal force field, this significantly improves particle removal efficiency and reduces the interference of catalyst particles on the extraction mass transfer process, thereby increasing the PAH extraction rate. PAHs are a core raw material for preparing superconducting carbon black; the improved extraction rate provides high-quality raw materials for subsequent conversion reactions, which is beneficial for forming highly conductive carbon structures.

[0136] In terms of the conductivity of the products, the volume resistivity of the superconducting carbon black prepared in Examples 1-3 was all below 0.35 Ω·cm, with Example 3 exhibiting the lowest volume resistivity at only 0.25 Ω·cm, demonstrating excellent conductivity. The volume resistivity of Comparative Example 1 was as high as 1.85 Ω·cm, mainly due to incomplete removal of catalyst particles. The residual particles formed insulating impurities in the carbon material, hindering the formation of the conductive network. Simultaneously, the low extraction rate of polycyclic aromatic hydrocarbons and insufficient purity of the raw materials resulted in numerous structural defects in the carbon after carbonization, leading to decreased conductivity. Comparative Example 2, which used conventional high-temperature graphitization instead of plasma graphitization, achieved a volume resistivity of 0.86 Ω·cm, which, while better than Comparative Example 1, was still significantly higher than Examples 1-3. This is because during plasma graphitization, high-temperature plasma has a high energy density, which can rapidly improve the graphitization degree of carbon materials. At the same time, the carbon atoms produced by methane cracking can repair carbon structural defects, forming a more regular graphitized structure and a three-dimensional interconnected conductive network. In contrast, conventional high-temperature graphitization has a slow heating rate, uneven temperature distribution, limited graphitization degree, many defects in the carbon structure, and poor conductivity.

[0137] From the perspective of particle size distribution and specific surface area, the proportion of the 50-200 nm fraction in Examples 1-3 all exceeded 92%, and the specific surface area was all above 870 m² / g, with the specific surface area of ​​Example 3 reaching 915 m² / g. Carbon black particles within this particle size range can better form a conductive network, and the high specific surface area is beneficial for increasing the contact area between the carbon black and the matrix material, further optimizing the conductivity. In Comparative Example 1, due to catalyst particle residue, particle agglomeration was severe during centrifugation classification, with the 50-200 nm fraction accounting for only 78.2% and the specific surface area only 623 m² / g. In Comparative Example 2, conventional high-temperature graphitization led to a certain degree of sintering of the carbon material, reducing the pore structure and lowering the specific surface area to 789 m² / g, lower than the examples.

[0138] In terms of nitrogen doping content and anisotropy content, the nitrogen doping content of Examples 1-3 is around 3.0 at%, with Example 3 reaching 3.5 at%, and the anisotropy content exceeding 95%. Nitrogen doping can optimize the surface electronic state of carbon materials and improve conductivity; high anisotropy content indicates high crystallinity of the mesophase pitch, laying the foundation for the subsequent formation of a regular graphitized structure. In Comparative Example 1, due to insufficient raw material purity, the anisotropy content of the mesophase pitch is only 88.6%, and impurities during nitrogen doping affect the grafting of functional groups, resulting in a nitrogen doping content of only 2.1 at%. The anisotropy content and nitrogen doping content of Comparative Example 2 are close to those of the Examples, but due to limitations in the degree of graphitization, its conductivity still cannot reach the level of the Examples.

[0139] Table 2: Comparison of process parameters and correlation analysis of product performance in Examples 1-3

[0140]

[0141] Table 2 compares the core process parameters and key performance indicators of the products in Examples 1-3, aiming to analyze the correlation between process parameters and product performance and provide a basis for process optimization.

[0142] Effect of electric field strength on product performance: The electric field strength of Example 3 was 3500 V / cm, higher than that of Example 1 (3000 V / cm) and Example 2 (2500 V / cm), and its catalyst particle removal rate reached 99.5%, the highest among the three. A higher electric field strength enhances the charged migration ability of catalyst particles, and under the synergistic effect of the centrifugal force field, more thoroughly removes particulate impurities, reducing the interference of impurities on subsequent reactions, thus resulting in the lowest volume resistivity (0.25 Ω·cm) and the largest specific surface area (915 m² / g) of the product. Example 2 had the lowest electric field strength and a slightly lower catalyst particle removal rate (98.8%). Although the extraction rate of polycyclic aromatic hydrocarbons was improved by adjusting the composite solvent ratio, the conductivity and specific surface area of ​​the product were still slightly inferior to those of Examples 1 and 3. This indicates that electric field strength is one of the key parameters affecting the purification effect and the final product performance. Within the range of 2000-5000 V / cm, appropriately increasing the electric field strength is beneficial to improving product performance.

[0143] Effect of composite solvent ratio on product performance: Example 2 used a composite solvent with a sulfolane to acetophenone mass ratio of 4:1, achieving a polycyclic aromatic hydrocarbon (PAH) extraction rate of 93.8%, higher than Example 1 (3:1, 92.5%) and Example 3 (2:1, 94.2%). Sulfolane has a strong solubility for PAHs, and increasing the proportion of sulfolane can improve the extraction capacity. However, excessive sulfolane will increase solvent recovery costs and may make subsequent flash evaporation and solvent removal more difficult. Example 3 used a composite solvent ratio of 2:1, with a higher proportion of acetophenone. Acetophenone has good dispersibility and can enhance the mass transfer effect of ultrasonic cavitation. Although the proportion of sulfolane was reduced, a high extraction rate of 94.2% was still achieved, and the product performance was optimal. This indicates that a composite solvent ratio within the range of 2:1 to 4:1 can achieve good extraction results and can be adjusted according to actual cost and product performance requirements.

[0144] Effects of catalyst type and loading on product performance: Examples 1 and 3 used iron phthalocyanine catalysts, while Example 2 used cobalt phthalocyanine catalysts. The catalyst loading in Example 3 (15%) was higher than that in Examples 1 (12%) and 2 (10%). Iron phthalocyanine catalysts exhibit higher catalytic activity for the directional polycondensation of aromatic molecules than cobalt phthalocyanine catalysts, more effectively inducing mesophase pitch formation and increasing anisotropy content. Higher loading increases the number of catalytically active sites, further optimizing the polycondensation reaction. Example 3 achieved the highest anisotropy content (97.1%) and nitrogen doping (3.5 at%) among the three examples, indicating that iron phthalocyanine catalysts and higher loading are more beneficial for improving the quality of mesophase pitch and subsequent surface modification, thereby optimizing the product's electrical conductivity.

[0145] Effect of plasma temperature on product properties: The plasma temperature of Example 3 was 2300℃, higher than that of Example 1 (2200℃) and Example 2 (2100℃), and its volume resistivity was the lowest. Higher plasma temperatures can enhance the graphitization degree of the carbon material, making the carbon structure more regular, while also promoting the deposition of carbon atoms from methane cracking and the repair of structural defects, forming a more complete three-dimensional interconnected conductive network. Example 2 had the lowest plasma temperature, relatively insufficient graphitization, and the highest product volume resistivity (0.32 Ω·cm), indicating that in the range of 2000-2500℃, plasma temperature is positively correlated with product conductivity. Appropriately increasing the plasma temperature is beneficial to improving the conductivity of the product, but it needs to be controlled within a reasonable range to avoid excessively high temperatures causing sintering of the carbon material, which would reduce the specific surface area.

[0146] Comprehensive analysis shows that Example 3, by optimizing process parameters (higher electric field strength, higher iron phthalocyanine loading, suitable composite solvent ratio, and higher plasma temperature), obtained the best-performing superconducting carbon black, which has low volume resistivity, large specific surface area, and high anisotropy content, demonstrating promising application prospects. Example 1 has balanced process parameters and excellent overall performance, making it suitable for large-scale industrial production. Example 2, by adjusting the composite solvent ratio, improved the extraction rate, meeting the requirements for scenarios with high raw material utilization.

[0147] TEM characterization of the superconducting carbon black prepared in Example 3 showed that it possessed a clear three-dimensional interconnected conductive network structure, with uniformly dispersed carbon particles. The particle size was mainly concentrated in the range of 50-200 nm, consistent with the results of laser particle size analysis. The carbon particles exhibited a high degree of graphitization, clear lattice fringes, and no obvious impurity particles, indicating excellent purification effects from the refining and post-processing units. XPS characterization revealed the presence of C, O, and N elements on the carbon black surface. Nitrogen primarily existed as pyridine nitrogen, pyrrole nitrogen, and graphitic nitrogen. These nitrogen-doped structures effectively optimized the surface electronic state of the carbon material, reduced electron transport resistance, and improved conductivity.

[0148] TEM characterization of the superconducting carbon black prepared in Comparative Example 1 showed severe particle agglomeration, obvious catalyst particle residue, numerous carbon structural defects, low graphitization degree, and lack of a complete three-dimensional interconnected conductive network, resulting in a significant increase in its volume resistivity. Although the superconducting carbon black prepared in Comparative Example 2 had no obvious impurity residue, its graphitization degree was lower than that of Example 3, with more defects in the lattice fringes and insufficient integrity of the three-dimensional conductive network; therefore, its conductivity still lagged behind.

[0149] The process for preparing superconducting carbon black by refining and separating catalytic oil slurry provided by this invention achieves efficient removal of catalyst particles and high-purity extraction of polycyclic aromatic hydrocarbons from the catalytic oil slurry through a refining unit consisting of electric field-coordinated centrifugal separation and ultrasonic-enhanced solvent extraction; a conversion unit consisting of catalytic condensation, template-guided carbonization, and plasma graphitization prepares carbon materials with ordered mesoporous structures and high graphitization; and a post-treatment unit consisting of graded purification and surface modification optimizes the particle size distribution and surface electronic state of the carbon materials, ultimately obtaining superconducting carbon black with a three-dimensional interconnected conductive network.

[0150] The results of Examples 1-3 show that the superconducting carbon black prepared by this process has a volume resistivity of less than 0.35 Ω·cm, a specific surface area of ​​more than 870 m² / g, and a 50-200 nm fraction accounting for more than 92%, exhibiting excellent performance in all aspects. Compared with the comparative examples, the process of this invention improves the purification effect through electric field-assisted centrifugal separation and enhances the graphitization degree through plasma graphitization, significantly optimizing the conductivity and microstructure of the product. Among them, Example 3 has the optimal process parameters, resulting in a product with a volume resistivity as low as 0.25 Ω·cm and a specific surface area of ​​915 m² / g, demonstrating the best overall performance.

[0151] This process not only realizes the high-value-added resource utilization of catalytic oil slurry and solves the problem of environmental pollution caused by catalytic oil slurry emissions, but also produces high-performance superconducting carbon black, which can be widely used in conductive rubber, conductive plastics, lithium-ion battery electrode materials and other fields, and has significant economic value and environmental significance.

[0152] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A process for preparing superconducting carbon black by refining and separating catalytic oil slurry, characterized in that, The process consists of a refining unit, a conversion unit, and a post-processing unit, executed sequentially. The refining unit first performs electric field-coordinated centrifugal separation on the catalytic oil slurry. During the separation process, a DC electric field of 1000-5000V / cm is continuously applied, and the centrifugal force field is 2000-6000G, simultaneously removing catalyst particles with a particle size greater than 1 micrometer. The separated slurry enters an ultrasonically enhanced solvent extraction tower, where it is countercurrently contacted with a composite solvent under the action of an ultrasonic field with a frequency of 20-40kHz. The composite solvent is a mixture of sulfolane and acetophenone in a mass ratio of 2:1 to 4:1, and the operating temperature is maintained at 70-95℃. The conversion unit receives the extract rich in polycyclic aromatic hydrocarbons from the purification unit and sequentially performs three core reactions: catalytic polycondensation, template-guided carbonization, and plasma graphitization. In the plasma graphitization step, a microwave source is turned on to generate plasma with a temperature of 2000-2500℃. The post-processing unit performs graded purification and surface modification on the carbon material produced by the conversion unit, ultimately obtaining superconducting carbon black with a three-dimensional interconnected conductive network.

2. The process for preparing superconducting carbon black by refining and separating catalytic oil slurry according to claim 1, characterized in that, The specific steps of the electric field-assisted centrifugal separation are as follows: The catalytic slurry, preheated to 90-110℃, is introduced into a centrifugal drum with coaxial cylindrical electrodes. The outer cylinder wall is connected to the positive terminal of a DC high-voltage power supply, and the central shaft is connected to the negative terminal. Start the centrifuge and rotate it to 3000-5000 rpm to create a centrifugal force field. At the same time, turn on the high voltage power supply to stabilize the electric field strength at 3000V / cm. Under the action of the centrifugal force field, the charged solid particles migrate toward the electrode plates and are captured by the rotating wall. The processing time is 25-40 minutes.

3. The process for preparing superconducting carbon black by refining and separating catalytic oil slurry according to claim 1, characterized in that, The specific steps of the ultrasound-enhanced solvent extraction are as follows: The clarified liquid after electric field centrifugation is fed from the middle of the extraction tower, and the composite solvent is fed from the top of the tower, controlling the volume ratio of solvent to oil slurry to be 1.5:1 to 2.5:1; The ultrasonic transducer array installed inside the tower generates a cavitation effect, which enhances mass transfer. The aromatic-rich extract phase is collected from the bottom of the column, and the raffinate phase is collected from the top of the column; the operating temperature inside the column is 85℃, the ultrasonic power density is 50-100W / L, and the residence time is 45-75 minutes.

4. The process for preparing superconducting carbon black by refining and separating catalytic oil slurry according to claim 1, characterized in that, The specific implementation method of the catalytic polycondensation step is as follows: The extract phase was flash-evaporated under a negative pressure of 0.095-0.099 MPa to remove most of the solvent, yielding a concentrate. Add 1%-3% by mass of the metal phthalocyanine catalyst to the concentrate and place it in a high-pressure reactor equipped with a magnetic stirrer and a reflux condenser. After replacing the air three times with high-purity nitrogen, the temperature is increased to 390-410℃ at a rate of 2℃ / min, and the pressure naturally rises to 1.5-2.5MPa. Under these conditions, the reaction is kept at a constant temperature for 3-5 hours to induce the directional condensation of aromatic molecules to form anisotropic mesophase spheres.

5. The process for preparing superconducting carbon black by refining and separating catalytic oil slurry according to claim 4, characterized in that, The metal phthalocyanine catalyst is iron phthalocyanine or cobalt phthalocyanine, which is pre-loaded on a porous silica support with a loading of 10%-15%. After the reaction is completed, the product is cooled to room temperature, and unreacted components and catalyst are removed by toluene extraction to obtain refined mesophase pitch with a softening point between 260-280℃ and an anisotropy content greater than 95%.

6. The process for preparing superconducting carbon black by refining and separating catalytic oil slurry according to claim 1, characterized in that, The specific implementation method of the template-guided carbonization step is as follows: the refined mesophase pitch is dissolved in tetrahydrofuran to prepare a solution with a mass concentration of 10%; the nanoporous magnesium oxide template is immersed in the solution and the solution is filled into the template pores by vacuum impregnation; after being taken out, it is dried at 60°C for 24 hours, and then heated to 900°C at 5°C / min under argon protection for 2 hours. After carbonization, the magnesium oxide template is removed by dissolving it in dilute hydrochloric acid, resulting in a primary carbon black framework with an ordered mesoporous structure.

7. The process for preparing superconducting carbon black by refining and separating catalytic oil slurry according to claim 1, characterized in that, The specific implementation method of the plasma graphitization step is as follows: the primary carbon black skeleton is placed on the graphite base of the microwave plasma chemical vapor deposition furnace, and the system is evacuated to 10... -2 After Pa, a mixture of argon and methane is introduced, with methane accounting for 5%-10% of the volume; the microwave source is turned on to generate plasma at a temperature of 2000-2500℃, and the processing time is 15-30 minutes.

8. The process for preparing superconducting carbon black by refining and separating catalytic oil slurry according to claim 1, characterized in that, The specific steps of the graded purification are as follows: The plasma-treated carbon material was placed in a 1 mol / L hydrofluoric acid solution and washed at 50°C for 4 hours to remove residual silicon-based impurities. Wash with deionized water until neutral; The material was then dispersed in ethanol and subjected to high-speed centrifugation for fractionation, and fractions with equivalent particle sizes of 50-200 nm corresponding to the sedimentation rate were collected.

9. The process for preparing superconducting carbon black by refining and separating catalytic oil slurry according to claim 8, characterized in that, The specific steps of the surface modification are as follows: the graded carbon material is dispersed in a mixed acid with a volume ratio of concentrated nitric acid to concentrated sulfuric acid of 1:3, and refluxed at 70°C for 2 hours to introduce carboxyl and hydroxyl oxygen-containing functional groups; after washing and drying, the treated material is annealed at 500°C for 1 hour by introducing ammonia gas into a tube furnace to achieve nitrogen doping of some functional groups, thereby optimizing its surface electronic state.

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