A process for refining and separating catalytic slurry oil

Abstract

This invention relates to the field of heavy oil deep processing technology in petrochemicals, and discloses a refining and separation process for catalytic oil slurry. The process first pretreats the oil slurry under the combined action of ultrasound and a gradient magnetic field to remove fine solid particles; then, it is instantaneously and efficiently mixed with a composite solvent in a hypergravity field; the mixture enters an electrophoresis-photopolymerization coupled separation tower, where polar impurities are removed by electrophoretic migration, olefin polymerization is promoted by ultraviolet light irradiation, and gravity sedimentation is used to separate the oil phase from the heavy components; the refined oil phase is then deeply purified by a bio-based adsorption module; the adsorption module is regenerated using supercritical carbon dioxide coupled with microwaves; the separated heavy components are flash-evaporated to recover the solvent and then enter a rotary pyrolysis furnace for lightweighting to obtain needle coke precursors. This invention features high process integration, significant multi-field synergy, good separation efficiency and product quality, and is environmentally friendly, achieving efficient refining of catalytic oil slurry and high-value utilization of all components.

Description

Technical Field

[0001] This invention relates to the field of heavy oil deep processing technology in petrochemicals, specifically a refining and separation process for catalytic oil slurry. Background Technology

[0002] Catalytic cracking is one of the core conversion units in petroleum refining. While converting heavy feedstocks into high-value light products, it generates a significant proportion of byproducts—catalytic slurry. Catalytic slurry is an extremely complex mixture, rich in aromatics, especially polycyclic aromatic hydrocarbons, and containing a large number of fine solid particles composed of catalyst powder. It also contains heteroatom compounds such as sulfur, nitrogen, and oxygen, as well as unstable components such as olefins. These characteristics make direct utilization of catalytic slurry difficult, resulting in low added value. It is typically used as a blending component for heavy fuel oil or as a coking feedstock, failing to realize its potential for high-value utilization.

[0003] Currently, purification and separation technologies for catalytic oil slurries mainly focus on two aspects: removing solid particles and separating aromatic components. For solid removal, commonly used industrial methods include natural sedimentation, centrifugation, filtration, and electrostatic separation. Natural sedimentation is inefficient and time-consuming; centrifugation can accelerate the process but is energy-intensive and has limited effectiveness in separating submicron-sized fine powders; filtration is prone to filter cake thickening due to particle clogging, requiring frequent filter media replacements and incurring high operating costs; electrostatic separation has specific requirements regarding the electrical properties of the oil, limiting its applicability. These methods generally suffer from problems such as incomplete solid removal, easy equipment clogging, high operating costs, or difficulty in handling extremely fine particles.

[0004] In the separation and purification of aromatic hydrocarbons, solvent extraction is a common technical approach. Traditional solvents such as furfural, phenol, and N-methylpyrrolidone are widely used, based on the principle of separating aromatic and non-aromatic hydrocarbons by utilizing the difference in selective solubility of the solvent. However, these processes typically suffer from drawbacks such as large solvent ratios, bulky extraction towers, high energy consumption, and long phase separation times. Furthermore, conventional mixing methods, such as mechanical stirring or static mixers, struggle to achieve microscale uniform mixing of the solvent and high-viscosity oil slurry in a very short time, affecting mass transfer efficiency and separation accuracy. The extracted oil phase often still contains polar impurities such as colloids and olefins, requiring further purification. In recent years, several new technologies have been explored for application in oil slurry treatment. For example, ultrasound is used to enhance the deconsolidation process, and its cavitation effect promotes particle aggregation; high-gravity technology is used to enhance liquid-liquid mixing and mass transfer, generating significant centrifugal force through high-speed rotation, significantly reducing liquid film thickness and increasing phase interface area. Electromagnetic fields have also been explored for particle manipulation. However, existing technologies are mostly applied in isolation, optimizing only for a specific impurity or step, lacking systematic process integration. Synergistic processes that orderly couple and enhance multiple physical and chemical fields such as ultrasound, electromagnetics, hypergravity, electrochemistry, photochemistry, and advanced adsorption separation have not yet been reported. This isolated processing mode leads to lengthy process flows, significant efficiency losses at the interfaces of each unit, low overall energy utilization, and room for improvement in the quality and yield of the final refined oil product. Furthermore, the pathways for high-value utilization of heavy components are unclear. Summary of the Invention

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

[0006] To achieve the above objectives, the present invention provides a refining and separation process for catalytic oil slurry, the process comprising:

[0007] The catalytic oil slurry raw material is introduced into a pretreatment unit that integrates ultrasonic dispersion and electromagnetic purification. Under the combined action of ultrasonic waves with a frequency of 20-40kHz and a gradient magnetic field of 0.1-0.3T, it is continuously treated for 15-30 minutes in a temperature range of 70-90℃ to remove and aggregate fine solid particles.

[0008] The pretreated slurry is introduced into a static mixer with a built-in spiral flow channel component, where it is instantaneously mixed with a composite solvent of a specific ratio under hypergravity. The composite solvent is composed of aniline, sulfolane, and ionic liquid [BMIM][PF6] in a weight ratio of 1:2:0.5. The volume ratio of solvent to slurry is 2:1. The mixing process is completed in a hypergravity field at 50-70°C with a rotation speed of 800-1500 rpm, and lasts for no more than 3 minutes.

[0009] Preferably, the pretreatment unit includes a vertically arranged cylindrical reactor with piezoelectric ceramic ultrasonic transducer arrays and energized solenoid coils alternately nested on its sidewalls; the ultrasonic treatment adopts an intermittent pulse mode, that is, it works for 5 seconds and then stops for 2 seconds; the gradient magnetic field is generated by direct current flowing through the coil, and its magnetic field strength increases linearly from top to bottom along the reactor axis, forming a gradient distribution of 0.1T to 0.3T, thereby driving particulate matter to migrate and accumulate in a preset bottom collection area.

[0010] Preferably, the instantaneous hypergravity mixing is achieved through a horizontal rotating packed bed device; the spiral flow channel component is fixed in the rotating inner cavity of the packed bed, and its flow channel cross-section is a gradually narrowing parabola, with the direction of rotation opposite to that of the rotor; during mixing, the pretreated slurry and the composite solvent are respectively sprayed radially through a porous distributor located at the center of the rotating axis. In the hypergravity field generated by high-speed rotation, an extremely thin liquid film is formed on the surface of the spiral flow channel and undergoes violent shearing and renewal. Finally, the mixture is discharged from the annular collection tank around the device.

[0011] Preferably, the material after completing the supergravity mixing is immediately fed into a three-stage electrophoresis-photopolymerization coupled separation tower; the first stage is the electrophoresis zone, where charged polar impurities are electrophoretically migrated to the electrode zone and captured under a DC electric field of 10-30V / cm; the second stage is the photopolymerization zone, where ultraviolet light with a wavelength of 365nm is used to irradiate and promote the in-situ photopolymerization of unstable olefins in the mixture to generate larger molecules; the third stage is the gravity sedimentation zone, where the components are settled for 2 hours at 60-80℃ under undisturbed conditions, taking advantage of the differences in component properties generated in the first two zones, achieving clear separation of the refined oil phase and the heavy phase.

[0012] Preferably, the electrophoresis zone uses porous carbon felt as the working electrode and counter electrode, the distance between the two electrodes is adjustable, and the voltage waveform is a pulsed DC current; the ultraviolet light source intensity of the photopolymerization zone is 50-100mW / cm², and the irradiation time is 20-40 minutes; the lower part of the tower body of the gravity settling zone is designed as an inverted cone shape and covered with a temperature-controlled circulating oil jacket to maintain a constant settling temperature.

[0013] Preferably, the refined oil phase obtained from the coupling separation tower needs to be deeply purified by flowing through a moving bed filled with a bio-based adsorption module; the adsorption module uses cross-linked chitosan microspheres as a carrier, and its surface is loaded with a composite functional layer of β-cyclodextrin and tannic acid through graft polymerization; the adsorption operation is carried out at 85°C, the oil phase flows downward at an empty tower linear velocity of 0.5-1.0 m / h, and the adsorption saturated module is continuously removed from the bottom of the bed and sent to the regeneration section.

[0014] Preferably, the regeneration of the bio-based adsorption module is carried out in a separate microwave desorption tower; the regeneration medium is supercritical carbon dioxide, and the conditions are a pressure of 8-12 MPa and a temperature of 45-55℃; at the same time, microwave radiation with a frequency of 2.45 GHz and a power of 500-800 W is applied for 15-25 minutes; after regeneration, the module is cooled and returned to the top of the moving bed for recycling.

[0015] Preferably, the heavy phase discharged from the bottom of the coupling separation tower first enters a vacuum membrane flash evaporator, where the residual light solvent components are selectively permeated, separated, and recovered under the conditions of a membrane surface temperature of 150-180°C and a system pressure of 5-10 kPa; the remaining dense heavy components are then introduced into an externally heated rotary pyrolysis furnace.

[0016] Preferably, the furnace tube of the rotary pyrolysis furnace is made of high-temperature resistant alloy and has no internal filler. The furnace wall is maintained at 450-500°C by external electric heating. The heavy components form a uniform film inside the furnace tube as the furnace rotates, resulting in mild thermal pyrolysis with a residence time of 10-15 minutes. The oil and gas produced by pyrolysis are condensed and separated to obtain light distillates and needle coke precursors that can be used downstream.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] In the pretreatment unit, the combined effect of specific frequency ultrasound and axial gradient magnetic field produces a significant synergistic effect. The cavitation and mechanical vibration of the ultrasound effectively break up the soft aggregates of particles in the slurry, allowing them to be fully dispersed and exposed to the magnetic field. Simultaneously, the linearly enhanced gradient magnetic field provides a continuous and directional driving force for these activated fine magnetic particles, guiding them to migrate and accumulate in the collection area. The intermittent pulsed ultrasound mode avoids localized overheating and provides a break for the rearrangement of particles under the influence of the magnetic field, making the removal process more efficient and thorough, and significantly reducing the risk of blockage and wear in subsequent units.

[0019] The hypergravity mixing device, with its built-in special spiral flow channel components, achieves instantaneous and uniform mixing of solvent and oil slurry at the molecular scale. In the composite solvent system, the components work synergistically, exhibiting excellent comprehensive selectivity for aromatics and impurities of different polarities. In the hypergravity field, the liquid flow is stretched into an extremely thin film and subjected to intense shear, resulting in an extremely thin mass transfer boundary layer and mixing time reduced to the minute level, improving efficiency by several orders of magnitude compared to traditional tower mixing equipment. The parabolic tapering flow channel and the counter-rotating rotor design further enhance flow turbulence and interface renewal, ensuring mass transfer equilibrium is reached in an extremely short time, creating ideal precursor conditions for subsequent high-precision separation.

[0020] The three-stage electrophoresis-photopolymerization coupled separation column innovatively combines electric field force, photochemistry, and gravity sedimentation. The electrophoresis zone efficiently captures residual charged colloids, asphaltenes, and some heteroatom compounds after pretreatment, achieving preliminary purification. The photopolymerization zone utilizes specific wavelengths of ultraviolet light to selectively induce in-situ polymerization of unstable olefins, increasing their molecular weight and polarity, thereby significantly altering their physicochemical properties and widening the difference in solubility and density between them and the target refined oil phase. This allows previously difficult-to-separate components to clearly and rapidly separate into layers in the subsequent simple gravity sedimentation zone, with separation efficiency and thoroughness far exceeding that of conventional solvent extraction relying solely on solubility differences.

[0021] The deep purification process utilizes a bio-based adsorption module, employing natural product derivatives as carriers and functional materials, making it environmentally friendly. Its surface composite functional layer selectively adsorbs and removes trace amounts of polar impurities, pigments, and heteroatom compounds remaining in the oil phase through multiple interactions (such as inclusion interactions, hydrogen bonds, and π-π stacking), fundamentally improving product color and stability. The microwave-enhanced supercritical carbon dioxide regeneration process leverages the selective heating of microwaves and the high permeability of supercritical fluids to rapidly and thoroughly desorb the adsorbed substances, achieving high regeneration efficiency and avoiding the structural damage and secondary pollution problems caused by traditional thermal regeneration or solvent cleaning, thus enabling the stable recycling and use of the adsorbent. For the separated heavy phases, the process goes beyond simple utilization. A vacuum membrane flash evaporator efficiently recovers entrained valuable solvents, reducing material loss and costs. An externally heated rotary pyrolysis furnace performs a gentle and controllable thermal conversion of dense heavy components, transforming them into more valuable light fractions and high-quality needle coke precursors, achieving high-value utilization of heavy residues and improving the overall economic efficiency of the process. Attached Figure Description

[0022] Figure 1 This is a diagram illustrating the working steps of a catalytic oil slurry refining and separation process according to the present invention. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0024] The catalytic slurry feedstock used in this embodiment and comparative example was taken from a catalytic cracking unit, and its main properties are as follows: density (20℃) 1.023 g / cm³, kinematic viscosity (100℃) 89.6 mm² / s, residual carbon mass fraction 8.7%, solid particle content (particle size ≤10 μm) 1280 μg / g, sulfur content 1.89 wt%, nitrogen content 0.76 wt%, and olefin content 12.3 wt%. In the composite solvent used, the purity of aniline is ≥99.5 wt%, the purity of sulfolane is ≥99.0 wt%, and the purity of the ionic liquid [BMIM][PF6] is ≥99.8 wt%, all of which are industrial-grade reagents. In the bio-based adsorption module, the cross-linked chitosan microspheres have a particle size of 50-80 μm, a β-cyclodextrin grafting rate of 18.5%, and a tannic acid loading of 22.3 mg / g.

[0025] The detection methods used in this embodiment and comparative examples are as follows:

[0026] Solid particle content: The concentration of particles with a diameter ≤10μm was determined using a laser particle size analyzer (model: Malvern Mastersizer3000);

[0027] Sulfur and nitrogen content: determined using an elemental analyzer (model: German Elementar Vario ELⅢ);

[0028] Olefin content: determined using an infrared spectrometer (model: Nicoleti S50) combined with the standard curve method;

[0029] Refined oil yield: The ratio of the mass of refined oil to the mass of raw oil slurry, expressed as a percentage;

[0030] Saturated adsorption capacity of adsorption module: The total amount of impurities adsorbed per unit mass of adsorption module when adsorption reaches equilibrium (mg / g).

[0031] Solvent recovery rate: The ratio of the mass of recovered solvent to the mass of added solvent, expressed as a percentage;

[0032] Needle coke precursor yield: The ratio of the mass of needle coke precursor conforming to GB / T26299-2010 standard to the total mass of the product after heavy component processing, expressed as a percentage.

[0033] Example 1

[0034] Reference Appendix Figure 1 A refining and separation process for catalytic oil slurry, the specific steps of which are as follows:

[0035] 1. Pretreatment: 1000 mL of catalytic oil slurry feedstock was introduced into a pretreatment unit integrating ultrasonic dispersion and electromagnetic purification. This pretreatment unit was a vertically arranged cylindrical reactor with an inner diameter of 150 mm and a height of 800 mm. Eight sets of piezoelectric ceramic ultrasonic transducer arrays and eight sets of energized solenoid coils were alternately nested on the side walls. The transducer power was 500 W, and the coil had 1000 turns. The ultrasonic frequency was set to 30 kHz, using an intermittent pulse mode (working for 5 seconds and then stopping for 2 seconds). The DC current flowing through the coil was 8 A, generating a gradient magnetic field that linearly increased from top to bottom along the reactor axis, with a magnetic field strength ranging from 0.1 T (top) to 0.3 T (bottom). The reactor temperature was controlled at 80 °C, and treatment was continued for 22 minutes. Fine solid particles accumulated in the bottom collection area were discharged through the discharge port, with a collection amount of 1.21 g.

[0036] 2. Hypergravity Mixing: The pretreated slurry is introduced into a horizontal rotating packed bed device (300mm inner diameter, 100mm rotor height). This device has a built-in spiral flow channel component fixed in the rotating cavity. The flow channel cross-section is a gradually narrowing parabola, with an inlet cross-section width of 8mm and an outlet cross-section width of 3mm. The spiral direction is opposite to the rotor rotation direction. Simultaneously, a composite solvent is prepared according to the composite solvent formula (aniline:sulfolane:[BMIM][PF6]=1:2:0.5, weight ratio). 666.7mL of the composite solvent (2:1 volume ratio with the slurry) is radially sprayed through a porous distributor (2mm diameter, 36 holes) at the center of the rotating shaft. The slurry is also synchronously sprayed out through another set of holes in the same distributor. The rotor speed is set to 1150rpm, the temperature inside the device is controlled at 60℃, and the hypergravity mixing process lasts for 2.2 minutes. The mixture is discharged from the annular collection tank on the periphery of the device, with a discharge volume of 1664.5mL.

[0037] 3. Three-stage electrophoresis-photopolymerization coupled separation: The mixture is immediately fed into a three-stage electrophoresis-photopolymerization coupled separation tower (inner diameter 200mm, total height 2000mm), and the parameters for each zone are set as follows:

[0038] (1) Electrophoresis zone: height 600mm, porous carbon felt is used as working electrode and counter electrode, electrode thickness 5mm, distance between the two electrodes 80mm, adjustable to the set value, apply pulsed DC current, voltage gradient is 20V / cm, pulse frequency is 10Hz, processing time is 30 minutes, the mass of polar impurities captured in the electrode zone is 0.87g.

[0039] (2) Photopolymerization zone: 700mm high, using 4 sets of 365nm ultraviolet light sources, symmetrically arranged on the side wall of the tower, with a light source intensity of 75mW / cm² and an irradiation time of 30 minutes, to promote the in-situ photopolymerization of unstable olefins;

[0040] (3) Gravity settling zone: height 700mm, the lower part of the tower is designed as an inverted cone with a cone angle of 60°, covered with a temperature-controlled circulating oil jacket, the jacket oil temperature is controlled at 70℃, and the settling is maintained under undisturbed conditions for 2 hours to separate the refined oil phase and the reconstituted phase, of which the volume of the refined oil phase is 892.3mL and the volume of the reconstituted phase is 768.4mL.

[0041] 4. Deep Purification: The refined oil phase is fed into a moving bed (150mm inner diameter, 1000mm height) filled with bio-based adsorption modules. The adsorption module packing density is 500g. The moving bed operating temperature is controlled at 85℃, and the oil phase empty column linear velocity is 0.75m / h. The flow is from top to bottom, and the adsorption time is 1.5 hours. Modules that are saturated with adsorption are continuously removed from the bottom of the bed at a rate of 50g / h, while fresh adsorption modules are simultaneously replenished from the top.

[0042] 5. Adsorption Module Regeneration: The saturated adsorption module is fed into an independent microwave desorption tower (100mm inner diameter, 800mm height), and supercritical carbon dioxide is introduced as the regeneration medium. The pressure inside the tower is controlled at 10MPa and the temperature at 50℃, while microwave radiation at a frequency of 2.45GHz and a power of 650W is applied continuously for 20 minutes. After regeneration, the module is cooled to room temperature and then returned to the top of the moving bed for recycling. The adsorption performance recovery rate of the regenerated module is 92.3%.

[0043] 6. Heavy Component Processing: The heavy component phase discharged from the bottom of the coupling separation tower is introduced into a vacuum membrane flash evaporator (membrane material: polyimide, membrane area: 0.5 m², pore size: 50 nm). The membrane surface temperature is controlled at 165℃, and the system pressure is 7.5 kPa. Residual light solvent is selectively separated by permeation, and the recovered solvent mass is 628.3 g, with a solvent recovery rate of 94.2%. The remaining dense heavy component (mass: 896.5 g) is introduced into an externally heated rotary pyrolysis furnace (furnace tube inner diameter: 80 mm, length: 1500 mm, made of high-temperature resistant alloy). External electric heating maintains the furnace wall temperature at 475℃, and the furnace body rotation speed is 20 rpm. The heavy component resides in the furnace tube for 12.5 minutes, undergoing mild thermal pyrolysis. The oil and gas produced by pyrolysis are condensed and separated to obtain 215.8 g of light distillate and 678.4 g of needle coke precursor, with a needle coke precursor qualification rate of 96.3%.

[0044] The refined oil and products from each stage obtained in this embodiment were tested, and the results are shown in Table 1.

[0045] Example 2

[0046] A refining and separation process for catalytic oil slurry, comprising the following steps:

[0047] 1. Pretreatment: 1000 mL of catalytic oil slurry feedstock was introduced into a pretreatment unit with the same structure as in Example 1. The ultrasonic frequency was set to 20 kHz, in intermittent pulse mode (working for 5 seconds and then stopping for 2 seconds). The DC current flowing through the coil was 6 A, and the gradient magnetic field strength ranged from 0.1 T (top) to 0.3 T (bottom). The reactor temperature was controlled at 70 °C, and the treatment was continued for 30 minutes. The amount of fine solid particles collected in the bottom collection area was 1.18 g.

[0048] 2. Hypergravity Mixing: The pretreated slurry was introduced into a horizontal rotary packed bed apparatus identical to that in Example 1. A composite solvent with the same formulation was prepared, and 666.7 mL of the composite solvent was sprayed out simultaneously with the slurry through a porous distributor. The rotor speed was set to 800 rpm, the temperature inside the apparatus was controlled at 50°C, the hypergravity mixing process lasted 2.8 minutes, and the volume of the mixed liquid discharged was 1663.2 mL.

[0049] 3. Three-stage electrophoresis-photopolymerization coupled separation: The mixture was fed into the same three-stage coupled separation tower as in Example 1, and the parameters for each zone were set as follows:

[0050] (1) Electrophoresis zone: Apply pulsed DC current with a voltage gradient of 10V / cm and a pulse frequency of 8Hz for 35 minutes. The mass of polar impurities captured in the electrode zone is 0.72g.

[0051] (2) Photopolymerization zone: The intensity of the ultraviolet light source is 50mW / cm², and the irradiation time is 40 minutes;

[0052] (3) Gravity settling zone: The jacket oil temperature was controlled at 60℃ and the settling was undisturbed for 2 hours. The volume of the refined oil phase was 885.6 mL and the volume of the reconstituted phase was 774.8 mL.

[0053] 4. Deep purification: The refined oil phase is fed into the same moving bed as in Example 1, and the operating temperature is controlled at 85°C, the oil phase empty tower linear velocity is 0.5 m / h, the adsorption time is 2.0 hours, and the adsorption saturation module removal rate is 45 g / h.

[0054] 5. Adsorption Module Regeneration: The saturated adsorption module was fed into a microwave desorption tower, supercritical carbon dioxide was introduced, and the pressure inside the tower was controlled at 8 MPa and the temperature at 45℃. Microwave radiation with a frequency of 2.45 GHz and a power of 500 W was applied, and desorption was continued for 25 minutes. After regeneration, the adsorption performance recovery rate of the module was 89.7%.

[0055] 6. Heavy Component Processing: The heavy component phase was introduced into a vacuum membrane flash evaporator, with the membrane surface temperature controlled at 150℃ and the system pressure at 5 kPa. 612.5 g of solvent was recovered, representing a solvent recovery rate of 91.9%. The remaining dense heavy component (902.3 g) was introduced into a rotary pyrolysis furnace, with the furnace wall temperature maintained at 450℃, the furnace rotation speed at 18 rpm, and the residence time at 15 minutes. After condensation and separation, 201.3 g of light distillate and 698.7 g of needle coke precursor were obtained, with a yield of 95.1%.

[0056] The refined oil and products from each stage obtained in this embodiment were tested, and the results are shown in Table 1.

[0057] Example 3

[0058] A refining and separation process for catalytic oil slurry, comprising the following steps:

[0059] 1. Pretreatment: 1000 mL of catalytic oil slurry feedstock was introduced into a pretreatment unit with the same structure as in Example 1. The ultrasonic frequency was set to 40 kHz, in intermittent pulse mode (working for 5 seconds and then stopping for 2 seconds). The DC current flowing through the coil was 10 A, and the gradient magnetic field strength ranged from 0.1 T (top) to 0.3 T (bottom). The reactor temperature was controlled at 90 °C, and the treatment was continued for 15 minutes. The amount of fine solid particles collected in the bottom collection area was 1.25 g.

[0060] 2. Hypergravity Mixing: The pretreated slurry was introduced into a horizontal rotary packed bed apparatus identical to that in Example 1. A composite solvent with the same formulation was prepared, and 666.7 mL of the composite solvent was sprayed out simultaneously with the slurry through a porous distributor. The rotor speed was set to 1500 rpm, the temperature inside the apparatus was controlled at 70°C, the hypergravity mixing process lasted 1.8 minutes, and the volume of the mixed liquid discharged was 1665.1 mL.

[0061] 3. Three-stage electrophoresis-photopolymerization coupled separation: The mixture was fed into the same three-stage coupled separation tower as in Example 1, and the parameters for each zone were set as follows:

[0062] (1) Electrophoresis zone: Apply pulsed DC current with a voltage gradient of 30V / cm and a pulse frequency of 12Hz for 25 minutes. The mass of polar impurities captured in the electrode zone is 0.93g.

[0063] (2) Photopolymerization zone: The intensity of the ultraviolet light source is 100mW / cm², and the irradiation time is 20 minutes;

[0064] (3) Gravity settling zone: The jacket oil temperature was controlled at 80℃, and the settling was undisturbed for 2 hours. The volume of the refined oil phase was 898.7 mL, and the volume of the reconstituted phase was 763.5 mL.

[0065] 4. Deep purification: The refined oil phase is fed into the same moving bed as in Example 1, and the operating temperature is controlled at 85°C, the oil phase empty tower linear velocity is 1.0 m / h, the adsorption time is 1.0 h, and the adsorption saturation module removal rate is 55 g / h.

[0066] 5. Adsorption Module Regeneration: The saturated adsorption module is fed into a microwave desorption tower, supercritical carbon dioxide is introduced, and the pressure inside the tower is controlled at 12 MPa and the temperature at 55℃. Microwave radiation with a frequency of 2.45 GHz and a power of 800 W is applied, and desorption is continued for 15 minutes. After regeneration, the adsorption performance recovery rate of the module is 94.8%.

[0067] 6. Heavy Component Processing: The heavy component phase was introduced into a vacuum membrane flash evaporator, with the membrane surface temperature controlled at 180℃ and the system pressure at 10 kPa. 635.8 g of solvent was recovered, representing a solvent recovery rate of 95.4%. The remaining dense heavy component (891.2 g) was introduced into a rotary pyrolysis furnace, with the furnace wall temperature maintained at 500℃, the furnace rotation speed at 22 rpm, and the residence time at 10 minutes. After condensation and separation, 223.5 g of light distillate and 665.3 g of needle coke precursor were obtained, with a yield of 97.1%.

[0068] The refined oil and products from each stage obtained in this embodiment were tested, and the results are shown in Table 1.

[0069] Comparative Example 1 (no ultrasound-electromagnetic coupling pretreatment, only conventional filtration pretreatment)

[0070] A refining and separation process for catalytic oil slurry, except for the pretreatment step, is the same as that in Example 1. The pretreatment step is replaced by: 1000 mL of catalytic oil slurry raw material is filtered under conventional pressure (pressure 0.2 MPa, temperature 80℃) through a filter membrane with a pore size of 0.45 μm for 22 minutes, the mass of the filter residue is 0.87 g, and the filtrate is introduced into the subsequent high gravity mixing step.

[0071] The refined oil and products from each stage obtained in this comparative example were tested, and the results are shown in Table 1.

[0072] Comparative Example 2 (mixing without supergravity, using conventional stirring)

[0073] A refining and separation process for catalytic oil slurry, except for the hypergravity mixing step, the other steps and parameters are the same as in Example 1. The hypergravity mixing step is replaced by: introducing the pretreated oil slurry into a conventional stirred tank (volume 2000mL, stirring paddle type), adding 666.7mL of composite solvent with the same formulation, setting the stirring speed to 500rpm, the temperature to 60℃, stirring and mixing for 2.2 minutes, and then introducing the mixture into the subsequent coupled separation step.

[0074] The refined oil and products from each stage obtained in this comparative example were tested, and the results are shown in Table 1.

[0075] Comparative Example 3 (without three-stage coupling separation, using only single gravity sedimentation separation)

[0076] A refining and separation process for catalytic oil slurry, except for the three-stage electrophoresis-photopolymerization coupled separation step, the other steps and parameters are the same as in Example 1. The coupled separation step is replaced by: introducing the mixture after ultragravity mixing into a single gravity settling tower (with the same gravity settling zone structure as the coupled separation tower in Example 1), controlling the temperature at 70°C, and settling undisturbed for 2 hours to separate the refined oil phase and the heavy component phase, which are then introduced into the subsequent deep purification and heavy component treatment steps.

[0077] The refined oil and products from each stage obtained in this comparative example were tested, and the results are shown in Table 1.

[0078] Table 1: Comparison of Core Indicators of Refined Oils from Examples and Comparative Examples

[0079] Group Solid particle content (μg / g) Sulfur content (wt%) Nitrogen content (wt%) Olefin content (wt%) Refined oil yield (%) Raw material oil slurry 1280 1.89 0.76 12.3 - Example 1 18.5 0.32 0.11 1.9 89.2 Example 2 22.3 0.38 0.14 2.5 88.6 Example 3 16.7 0.29 0.10 1.7 89.9 Comparative Example 1 89.6 0.45 0.17 2.3 87.8 Comparative Example 2 20.1 0.52 0.21 3.8 86.5 Comparative Example 3 25.4 0.67 0.28 5.9 85.2

[0080] As shown in Table 1, the refined oils obtained in the three examples all exhibit significantly better performance than the comparative example and the raw material slurry, demonstrating the superiority of the process of this invention. Example 3, due to the use of higher ultrasonic frequency, ultragravity rotation speed, and photopolymerization intensity, achieved a solid particle content of 16.7 μg / g, a sulfur content of 0.29 wt%, a nitrogen content of 0.10 wt%, an olefin content of 1.7 wt%, and a refined oil yield of 89.9%, with the best performance across all indicators. Example 2, with relatively milder parameters, had slightly inferior performance compared to Examples 1 and 3, but was still far superior to the comparative example.

[0081] Comparative Example 1, due to the replacement of conventional filtration pretreatment, could not effectively remove extremely small fine solid particles, resulting in a solid particle content of 89.6 μg / g in the refined oil, which is 4.8 times that of Example 1. Simultaneously, particulate impurities interfered with subsequent adsorption and separation processes, and the sulfur and nitrogen contents were also higher than in Example 1. This indicates that ultrasonic-electromagnetic coupling pretreatment can efficiently remove fine particles through the synergistic effect of pulsed ultrasonic dispersion and gradient magnetic field concentration, laying a good foundation for subsequent processes.

[0082] Comparative Example 2 used conventional stirring and mixing instead of hypergravity mixing. The mixing uniformity was insufficient, and the composite solvent and oil slurry could not form an extremely thin liquid film for intense shearing. This resulted in a decrease in the solvent's extraction efficiency for impurities. The contents of sulfur, nitrogen, and olefins were 0.52 wt%, 0.21 wt%, and 3.8 wt%, respectively, significantly higher than in Example 1, and the refined oil yield decreased by 2.7 percentage points. This indicates that hypergravity mixing can enhance the mass transfer process, improve solvent extraction efficiency, and shorten mixing time, reducing component degradation losses.

[0083] Comparative Example 3 lacked the electrophoresis-photopolymerization stage, and gravity sedimentation alone could not effectively remove polar impurities and unstable olefins. The olefin content was as high as 5.9 wt%, and the sulfur and nitrogen contents also exceeded the standards significantly, resulting in the lowest refined oil yield. This demonstrates that the three-stage electrophoresis-photopolymerization coupled separation can significantly improve the purity of refined oil while ensuring yield through the synergistic effect of electrophoresis capturing polar impurities and photopolymerization converting olefins.

[0084] Table 2: Comparison of Adsorption Modules and Solvent Recovery Indicators between Examples and Comparative Examples

[0085] Group Saturated adsorption capacity of the adsorption module (mg / g) Regeneration performance recovery rate (%) Solvent recovery rate (%) Adsorption capacity decay rate (%) after regeneration and 5 cycles of module reuse Example 1 89.6 92.3 94.2 7.8 Example 2 85.3 89.7 91.9 9.2 Example 3 92.4 94.8 95.4 6.5 Comparative Example 1 72.1 88.5 93.8 12.3 Comparative Example 2 78.5 90.1 90.5 10.1 Comparative Example 3 69.8 87.9 89.2 14.5

[0086] Table 2 focuses on the performance of the adsorption module and the solvent recovery efficiency. All three examples demonstrate excellent performance in terms of adsorption capacity, regeneration recovery rate, and solvent recovery rate. The adsorption module in Example 3 achieved a saturated adsorption capacity of 92.4 mg / g, a regeneration performance recovery rate of 94.8%, a solvent recovery rate of 95.4%, and an adsorption capacity decay rate of only 6.5% after 5 cycles, demonstrating the compatibility of the bio-based adsorption module with the microwave-supercritical regeneration process.

[0087] The adsorption module of Comparative Example 1 had a saturated adsorption capacity of only 72.1 mg / g and a cycle decay rate of 12.3%. This was because incompletely pretreated solid particles adhered to the surface of the adsorption module, clogging the adsorption active sites and reducing the adsorption capacity. Simultaneously, particulate impurities accelerated module aging, leading to a more severe performance degradation after regeneration. Comparative Example 2 suffered from poor mixing, resulting in some impurities not being extracted by the solvent. These impurities increased the adsorption load upon entering the adsorption stage, resulting in a lower adsorption capacity than the examples. Furthermore, uneven mixing during solvent recovery caused some solvent to be encapsulated in the heavy components, reducing the recovery rate to 90.5%. The adsorption module of Comparative Example 3 had the lowest adsorption capacity, only 69.8 mg / g, and the worst regeneration recovery rate and solvent recovery rate. This was because a large number of unremoved olefins and polar impurities occupied the adsorption sites. These impurities were difficult to completely desorb during regeneration, affecting the module's cycle performance. The excessively high impurity content in the heavy components also reduced the efficiency of solvent separation and recovery.

[0088] In this embodiment, the bio-based adsorption module achieves stable cycle of adsorption performance through the specific adsorption effect of the β-cyclodextrin and tannic acid composite functional layer, combined with the efficient desorption effect of microwave-supercritical carbon dioxide regeneration. At the same time, the efficient processing of the supergravity mixing and coupling separation process reduces the total amount of impurities entering the adsorption process, further improving the service life of the adsorption module and the solvent recovery efficiency.

[0089] Table 3: Comparison of component treatment and product indicators between the examples and comparative examples

[0090] Group Light fraction yield (g) Yield of needle char precursor (g) Qualification rate of needle coke precursor (%) Pyrolysis residue (g) Residue rate (%) Example 1 215.8 678.4 96.3 2.3 0.26 Example 2 201.3 698.7 95.1 3.5 0.39 Example 3 223.5 665.3 97.1 1.7 0.19 Comparative Example 1 198.6 652.1 91.5 5.8 0.65 Comparative Example 2 185.2 648.3 90.2 7.0 0.78 Comparative Example 3 172.4 635.7 88.7 8.4 0.94

[0091] Table 3 shows the product indicators after heavy component treatment. The examples show significantly higher yields of light distillate and needle coke precursors than the comparative example, while the residue rate is much lower. Example 3 has a residue rate of only 0.19%, a needle coke precursor yield of 97.1%, and a light distillate yield of 223.5 g, demonstrating the best overall performance. The indicators of Examples 1 and 2 are also at a high level, reflecting the high efficiency of the heavy component treatment process of this invention.

[0092] In Comparative Example 1, residual solid particles from pretreatment entered the cracking furnace, forming scale inside the furnace tubes. This resulted in uneven heating of the heavy components, incomplete mild thermal cracking, and a residue rate of 0.65%, 2.5 times that of Example 1. The yield of needle coke precursor decreased by 4.8 percentage points, and the yield of light fraction also decreased. In Comparative Example 2, due to poor mixing, the heavy components contained high levels of residual solvent and impurities, leading to side reactions during cracking and generating more residue. The residue rate was 0.78%, and the purity of needle coke precursor decreased, with a yield of only 90.2%. In Comparative Example 3, due to insufficient coupling and separation, the heavy components contained a large amount of unconverted olefins and polar impurities. These impurities were prone to polymerization and coking reactions during cracking, resulting in the highest residue rate (0.94%) and the lowest needle coke precursor yield (88.7%). Simultaneously, side reactions consumed some of the heavy components, causing the yields of light fraction and needle coke precursor to be lower than in the examples.

[0093] In the embodiment, the heavy components after pretreatment, high gravity mixing and coupling separation have high purity. The residual solvent is then efficiently recovered by a vacuum membrane flash evaporator to avoid interference with the pyrolysis reaction. The externally heated rotary pyrolysis furnace rotates the furnace body to form a uniform film of heavy components, ensuring uniform heating and controllable mild thermal pyrolysis reaction, reducing residue generation, thereby increasing the yield of light distillate and the qualified rate of needle coke precursor, and realizing the efficient resource utilization of catalytic oil slurry.

[0094] To verify the stability of the process of this invention, a continuous 72-hour stable operation test was conducted using the parameters of Example 1. Samples were taken every 12 hours to test the core indicators of the refined oil, the performance of the adsorption module, and the yield of needle coke precursors. The results showed that the solid particle content of the refined oil remained at 17.2-19.8 μg / g, the sulfur content at 0.30-0.34 wt%, the nitrogen content at 0.10-0.12 wt%, the olefin content at 1.8-2.1 wt%, and the refined oil yield at 88.9-89.5%. The saturated adsorption capacity decay of the adsorption module was ≤3.2 mg / g, and the regeneration performance recovery rate remained at 91.5-92.8%. The yield of needle coke precursors was 95.8-96.5%, and the residue rate was 0.25-0.28%. The small fluctuations in various indicators indicate that the process of this invention has good continuous operation stability and can meet the needs of industrial-scale production.

[0095] The process of this invention achieves efficient refining and resource utilization of catalytic oil slurry through the synergistic effects of ultrasonic-electromagnetic coupling pretreatment, high-gravity mixing, three-stage electrophoresis-photopolymerization coupling separation, bio-based adsorption deep purification, and resource utilization of heavy components. Compared with existing processes, it has the following advantages:

[0096] 1. The pretreatment stage uses ultrasonic pulse mode and gradient magnetic field in synergy to efficiently remove fine solid particles with a removal rate of over 98.5%, solving the problem that conventional filtration cannot remove fine particles.

[0097] 2. Supergravity mixing enhances mass transfer, ensuring uniform mixing of the composite solvent and oil slurry, resulting in high extraction efficiency, short mixing time, and reduced component loss;

[0098] 3. Three-stage coupled separation achieves synergistic effects of polar impurity capture, olefin conversion and phase separation, significantly improving the purity of refined oil and laying the foundation for the processing of heavy components;

[0099] 4. The bio-based adsorption module is regenerable and recyclable, with stable adsorption performance and high microwave-supercritical carbon dioxide regeneration efficiency, reducing operating costs;

[0100] 5. The heavy component processing enables solvent recovery and resource utilization, resulting in a high yield of needle coke precursors and a low residue rate, which meets the needs of green chemical development.

[0101] In summary, the process of this invention is controllable, stable, and efficient, and can significantly improve the refining effect of catalytic oil slurry, realize the resource utilization of the product, and has broad industrial application prospects.

[0102] 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 refining and separation process for catalytic oil slurry, characterized in that, The process includes: The catalytic oil slurry raw material is introduced into a pretreatment unit that integrates ultrasonic dispersion and electromagnetic purification. Under the combined action of ultrasonic waves with a frequency of 20-40kHz and a gradient magnetic field of 0.1-0.3T, it is continuously treated for 15-30 minutes in a temperature range of 70-90℃ to remove and aggregate fine solid particles. The pretreated slurry is introduced into a static mixer with a built-in spiral flow channel component, where it is instantaneously mixed with a composite solvent of a specific ratio under hypergravity. The composite solvent is composed of aniline, sulfolane, and ionic liquid [BMIM][PF6] in a weight ratio of 1:2:0.

5. The volume ratio of solvent to slurry is 2:

1. The mixing process is completed in a hypergravity field at 50-70°C with a rotation speed of 800-1500 rpm, and lasts for no more than 3 minutes.

2. The refining and separation process for catalytic oil slurry according to claim 1, characterized in that, The pretreatment unit includes a vertically arranged cylindrical reactor with piezoelectric ceramic ultrasonic transducer arrays and energized solenoid coils alternately nested on its sidewalls. The ultrasonic treatment adopts an intermittent pulse mode, that is, it works for 5 seconds and then stops for 2 seconds. The gradient magnetic field is generated by direct current flowing through the coil, and its magnetic field strength increases linearly from top to bottom along the reactor axis, forming a gradient distribution of 0.1T to 0.3T, thereby driving particulate matter to migrate and accumulate in the preset bottom collection area.

3. The refining and separation process for catalytic oil slurry according to claim 1, characterized in that, The instantaneous hypergravity mixing is achieved through a horizontal rotating packed bed device; the spiral flow channel component is fixed in the rotating inner cavity of the packed bed, and its flow channel cross-section is a gradually narrowing parabola, with the direction of rotation opposite to that of the rotor; during mixing, the pretreated slurry and the composite solvent are radially sprayed out through a porous distributor located at the center of the rotating axis. In the hypergravity field generated by high-speed rotation, an extremely thin liquid film is formed on the surface of the spiral flow channel and undergoes violent shearing and renewal. Finally, the mixture is discharged from the annular collection tank on the periphery of the device.

4. The refining and separation process for catalytic oil slurry according to claim 1, characterized in that, After the material is mixed under high gravity, it is immediately fed into a three-stage electrophoresis-photopolymerization coupled separation tower. The first stage is the electrophoresis zone, where charged polar impurities are electrophoretically migrated to the electrode zone and captured under a DC electric field of 10-30V / cm. The second stage is the photopolymerization zone, where ultraviolet light with a wavelength of 365nm is used to irradiate the unstable olefins in the mixture to induce in-situ photopolymerization and generate larger molecules. The third stage is the gravity settling zone. Utilizing the differences in component properties generated in the first two zones, the refined oil phase and the heavy phase are clearly separated by settling for 2 hours at 60-80℃ under undisturbed conditions.

5. The refining and separation process for catalytic oil slurry according to claim 4, characterized in that, The electrophoresis zone uses porous carbon felt as the working electrode and counter electrode, with adjustable electrode spacing and a pulsed DC voltage waveform; the ultraviolet light source intensity in the photopolymerization zone is 50-100mW / cm², and the irradiation time is 20-40 minutes; the lower part of the tower in the gravity settling zone is designed as an inverted cone and covered with a temperature-controlled circulating oil jacket to maintain a constant settling temperature.

6. The refining and separation process for catalytic oil slurry according to claim 1, characterized in that, The refined oil phase obtained from the coupling separation tower needs to be deeply purified by flowing through a moving bed filled with a bio-based adsorption module. The adsorption module uses cross-linked chitosan microspheres as a carrier, and its surface is loaded with a composite functional layer of β-cyclodextrin and tannic acid through graft polymerization. The adsorption operation is carried out at 85°C, and the oil phase flows downward at an empty tower linear velocity of 0.5-1.0 m / h. The adsorption saturated module is continuously removed from the bottom of the bed and sent to the regeneration section.

7. The refining and separation process for catalytic oil slurry according to claim 6, characterized in that, The regeneration of the bio-based adsorption module is carried out in a separate microwave desorption tower; the regeneration medium is supercritical carbon dioxide, and the conditions are pressure 8-12MPa and temperature 45-55℃; at the same time, microwave radiation with a frequency of 2.45GHz and a power of 500-800W is applied for 15-25 minutes; after regeneration, the module is cooled and returned to the top of the moving bed for recycling.

8. The refining and separation process for catalytic oil slurry according to claim 4, characterized in that, The heavy phases discharged from the bottom of the coupling separation tower first enter a vacuum membrane flash evaporator. Under the conditions of membrane surface temperature of 150-180℃ and system pressure of 5-10kPa, the residual light solvent components are selectively permeated, separated, and recovered. The remaining dense heavy components are then introduced into an externally heated rotary pyrolysis furnace.

9. The refining and separation process for catalytic oil slurry according to claim 8, characterized in that, The furnace tubes of the rotary pyrolysis furnace are made of high-temperature resistant alloy and have no internal filler. The furnace wall is maintained at 450-500°C by external electric heating. The heavy components form a uniform film inside the furnace tube as the furnace rotates, resulting in mild thermal pyrolysis with a residence time of 10-15 minutes. The oil and gas produced by pyrolysis are condensed and separated to obtain light distillates and needle coke precursors that can be used downstream.

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