A method and system for low energy consumption desolidification of catalytic cracking slurry

Abstract

The application relates to a low-energy-consumption solid-removing method and system for catalytic cracking slurry, and relates to the field of catalytic cracking slurry treatment. The catalytic cracking slurry which is heat-exchanged and does not add dilution solvent is directly subjected to electric field electrostatic separation treatment, the slurry after the electrostatic separation treatment is subjected to filtering and solid-removing treatment, and the purification of the slurry is completed. Meanwhile, the slurry generated by the filtering and solid-removing treatment is back-flushed by the purified slurry after the solid-removing treatment, the back-flushed slurry and the slurry discharged by the electrostatic separation are mixed with the dilution solvent, and then the mixture is subjected to filtering treatment again to separate heavy slurry and solid particles. The application directly sends the slurry into the electric field for separation treatment without adding the dilution solvent, the separated slurry is subjected to filtering and solid-removing treatment, then the slurry is back-flushed by a part of the purified slurry, and then the slurry is added into the dilution solvent for secondary filtering treatment. The energy consumption of the equipment is greatly reduced, and the yield of the purified slurry is higher.

Description

Technical Field

[0001] This invention relates to the field of catalytic cracking slurry treatment, specifically a low-energy desolidification method and system for catalytic cracking slurry. Background Technology

[0002] Catalytic cracking slurry is a byproduct of catalytic cracking, and its reuse is limited due to the presence of solid particles. Statistics show that the solid content of catalytic cracking slurry in major domestic refineries ranges from 0.17 to 8.3 g / L, with an average of approximately 0.3 g / L. In recent decades, research on catalytic cracking slurry solidification technologies has focused on methods such as natural sedimentation, centrifugation, filtration, additive sedimentation, and electrostatic separation. Among these methods, filtration and electrostatic separation are currently the hot research topics.

[0003] The advantage of filtration is that the type of filter material can be selected according to the size of the solid particles in the catalytic slurry, theoretically achieving complete removal of solid particles. However, in practical applications, filtration is prone to problems such as filter material clogging and regeneration difficulties, making continuous operation difficult. This is mainly due to the presence of asphalt-like substances (average content approximately 5%) in the catalytic slurry. Asphalt-like substances have high viscosity and strong adsorption properties, easily adsorbing onto the filter material surface when the catalytic slurry passes through, causing clogging. Furthermore, their high viscosity and strong adhesion to the filter material surface make regeneration difficult.

[0004] Electrostatic separation offers advantages such as applicability to various types of catalytic slurries, the elimination of consideration for particle size, and the absence of equipment clogging issues. However, it suffers from low efficiency and difficulty in achieving ultra-clean removal of fine particles from catalytic slurries. This is because electrostatic separation relies on the polarization of an electric field to induce a charge in the solid particles, causing them to move directionally along the field's direction. This leads to particle aggregation and growth, followed by sedimentation, separation, and removal under gravity. Therefore, for larger particles, electrostatic separation readily induces aggregation and growth to a size suitable for sedimentation; however, for smaller particles, this process takes longer, reducing efficiency. Furthermore, adding adsorption packing to the electric field treatment device can cause solid particles to adsorb onto the packing, potentially leading to electric field conduction and collapse, resulting in issues with packing regeneration and stability.

[0005] Since filtration methods are insufficient to remove the coupling of asphaltene micelles and fine solid particles from slurry oil, electrostatic separation can quickly separate the micelles. Therefore, existing technologies include methods that combine both to treat catalytic cracking slurry oil. However, directly subjecting the slurry to electric field or filtration treatment results in a short operating cycle for the equipment due to its high viscosity, making continuous production impossible. Therefore, existing technologies generally involve first adding a diluent to reduce the viscosity of the slurry oil before electrostatic or filtration treatment. A representative example is a catalytic cracking slurry purification method disclosed in patent publication number CN109207193B. This patent discloses a method for mixing and separating the slurry oil with light solvent oil, followed by high-voltage electric field separation of the light oil, and then filtering the separated slurry oil through a bed filter to obtain a clarified slurry oil.

[0006] This treatment method, which combines electrostatic separation and filtration, can extend the operating cycle of the filtration system and improve the treatment efficiency of catalytic cracking slurry, but the entire process is extremely energy-intensive. Summary of the Invention

[0007] To address the excessive energy consumption problem associated with the existing combination of electrostatic separation and filtration methods for treating catalytic cracking slurry, this invention provides a low-energy-consumption desoldering method and system for catalytic cracking slurry. This method overcomes the technical bias of existing technologies that require the addition of diluents to reduce the viscosity of the slurry before it can undergo electric field treatment or filtration. Instead, it employs an electric field followed by filtration, using backwashing to remove the oil residue generated during filtration. The slurry generated by the electric field and the oil residue backwashed from the filtration device are then mixed with a diluent and filtered again. This treatment method not only significantly reduces the energy consumption of the equipment but also achieves a higher yield of purified slurry.

[0008] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a low-energy-consumption desolidification method for catalytic cracking slurry, wherein the catalytic cracking slurry after heat exchange and without the addition of diluent is directly subjected to electrostatic separation treatment, and the slurry after electrostatic separation treatment is then subjected to filtration desolidification treatment to complete the purification of the slurry; at the same time, the purified slurry after desolidification treatment is used to backwash out the slurry produced by filtration desolidification, and then the backwashed slurry, the slurry discharged by electrostatic separation, and the diluent are mixed and filtered again to separate the heavy oil slurry and solid particles.

[0009] As an optimized solution for the above-mentioned low-energy desolidification method for catalytic cracking slurry, the temperature of the catalytic cracking slurry after heat exchange is 100-350℃, preferably 100-250℃, and most preferably 150-250℃.

[0010] As another optimized solution for the above-mentioned low-energy desolidification method for catalytic cracking slurry, the asphalt content in the slurry after electrostatic separation treatment is less than 1%, preferably less than 0.5%, and most preferably less than 0.2% before entering the filtration desolidification treatment.

[0011] As another optimized scheme of the above-mentioned low-energy desolidification method for catalytic cracking slurry, the electric field in the electrostatic separation treatment is an alternating electric field, a direct current electric field, or a pulsed electric field, preferably a direct current electric field and a pulsed electric field, and most preferably a direct current electric field.

[0012] As another optimized solution for the above-mentioned low-energy desolidification method for catalytic cracking slurry, the electric field strength during the electrostatic separation treatment is 500-15000V / cm, preferably 2000-15000V / cm, and most preferably 3000-8000V / cm.

[0013] As another optimized solution for the above-mentioned low-energy desolidification method for catalytic cracking slurry, the residence time of the catalytic cracking slurry during electrostatic separation treatment is less than 4 hours, preferably less than 2 hours.

[0014] As another optimized solution for the above-mentioned low-energy desolidification method for catalytic cracking slurry, the filter packing used in the filtration desolidification process has a pore size of less than 100 μm, preferably less than 20 μm, and most preferably less than 5 μm.

[0015] As another optimized solution for the above-mentioned low-energy desolidification method of catalytic cracking slurry, the setting conditions for backwashing and filtering the slurry generated by desolidification using the purified slurry after desolidation treatment are as follows: the pressure difference before and after the filter device is 100-600KPa, or the filtration time is 12-72h, or the frequency of regular cleaning is 7-30 days / time.

[0016] As another optimized solution for the above-mentioned low-energy desolidification method for catalytic cracking slurry, after the two slurries are mixed with diluent and filtered again, the solvent needs to be recovered through solvent recovery treatment.

[0017] A low-energy desolidification system for catalytic cracking slurry includes an electric field treatment device and a slurry filtration device. Catalytic cracking slurry without added diluent is directly fed into the electric field treatment device for pretreatment. The pretreated slurry then enters the slurry filtration device for filtration and desolidification, thus completing the desolidification process. The slurry filtration device is equipped with a backwashing system. The slurry automatically discharged from the electric field treatment device and the slurry discharged after backwashing from the slurry filtration device are mixed with a diluent and then sent to the slurry filtration device for further processing to separate heavy oil slurry and solid particles.

[0018] As an optimized solution for the aforementioned low-energy desolidification system for catalytic cracking slurry, the purified slurry outlet of the slurry filtration device is connected to a desolidified slurry collection device, and the desolidified slurry collection device returns the collected purified slurry to the slurry filtration device and the desolidified slurry collection device through a pipeline.

[0019] As another optimized solution for the above-mentioned low-energy desolidification system for catalytic cracking slurry, the desolidified slurry collection device is equipped with a backflushing oil pipeline. The backflushing oil includes, but is not limited to, purified slurry in the purified slurry collection device, catalytic diesel, diesel, wax oil, and one or more of other petroleum distillate oils.

[0020] As another optimized solution for the above-mentioned low-energy desolidification system for catalytic cracking slurry, the filtrate outlet of the slurry filtration device is connected to a solvent recovery device, and the solvent recovery device mixes the separated solvent with the slurry discharged after backwashing through a pipeline.

[0021] As another optimized solution for the aforementioned low-energy desolidification system for catalytic cracking slurry, the slurry filtration device has a backwashing pipeline, and a solvent recovery device is connected to the backwash liquid outlet of the slurry filtration device. The solvent recovery device separates the solvent from the solid particles and mixes the solvent again with the slurry discharged after backwashing through the pipeline.

[0022] As another optimized solution for the above-mentioned low-energy desolidification system for catalytic cracking slurry, the slurry filtration device and the residue filtration device form a set of filtration units, and another set of filtration units with the same structure is set in parallel with this set of filtration units. The two sets of filtration units are one in operation and one on standby.

[0023] This invention leverages the advantages of both filtration and electrostatic methods. By utilizing the charged properties of asphalt and the polarization effect of an electric field, it removes viscous asphalt-like substances and larger solid particles from the catalytic slurry, achieving initial purification of the catalytic slurry. Then, the slurry purified by electrostatic method is passed through a filter material to further remove fine particles. By combining the two methods, the problems of easy clogging and difficult regeneration in filtration are solved, while the low efficiency of electrostatic method in removing fine particles is also addressed. Therefore, continuous and efficient removal of catalytic slurry can be achieved.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) The catalytic cracking slurry of the present invention is directly fed into the electric field separation process without the addition of diluent solvent. The separated slurry is then filtered and desolidified. After that, a portion of the purified slurry is used to backwash the filtered and desolidified slurry. The slurry is then added to the diluent solvent and filtered a second time. This not only greatly reduces the energy consumption of the equipment, but also increases the yield of purified slurry.

[0026] 2) This invention is a highly efficient oil slurry desolidification combined method developed based on electrostatic separation and filtration. It not only solves the problems of easy clogging and frequent backwashing required by filtration, but also solves the problem of low efficiency of electrostatic method in removing fine particles, and greatly extends the operating cycle of the equipment. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the equipment process flow of the present invention;

[0028] Figure 2 This is a flowchart for comparison. Detailed Implementation

[0029] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. Parts not explained in the following embodiments of the present invention should be understood as technologies known or should be known by those skilled in the art, such as the structure of heat exchange device, electric field treatment device, oil slurry filtration device, desolidified oil slurry collection device and solvent recovery device of catalytic cracking oil slurry.

[0030] Example 1

[0031] A low-energy-consumption desolidification method for catalytic cracking slurry, such as Figure 1 As shown, the catalytic cracking slurry, after heat exchange and without the addition of diluent, is directly subjected to electrostatic separation treatment. The slurry after electrostatic separation treatment is then filtered and desolidified to complete the purification of the slurry. At the same time, the purified slurry after desolidification treatment is used to backwash out the slurry produced by filtration and desolidification. The backwashed slurry and the slurry discharged from electrostatic separation are then mixed with diluent and filtered again to separate the heavy oil slurry and solid particles.

[0032] In this embodiment, the solid content of the catalytic cracking slurry used is 3000 μg / g and the bitumen content is 3.5 wt.%.

[0033] The temperature of the catalytic cracking slurry after heat exchange is 100°C;

[0034] The diluent is propane;

[0035] Testing revealed that the asphalt content in the slurry after electrostatic separation treatment was 2.98% before it entered the filtration and desolidification process.

[0036] The electric field in the electrostatic separation process is an alternating electric field with a field strength of 500 V / cm. The residence time of the catalytic cracking slurry during the electrostatic separation process is 4 hours.

[0037] During the filtration and desolidification process, the pore size of the filter media used is less than 100 μm;

[0038] During operation, the electric field treatment device operates stably, with the current remaining stable at around 5A. The asphalt content of the catalytic slurry after electric field treatment is reduced to 2.98 wt.%. The slurry filtration device operates stably, reaching a pressure drop of 500 kPa in approximately 3 hours, after which backwashing regeneration is initiated, during which the filter media is regenerated. The slurry filtration device reaches a pressure drop of 500 kPa in approximately 12 hours, after which backwashing regeneration is initiated, during which the filter media is easily regenerated. In this operation, the slurry and slurry filtration devices form a filtration unit, and another filtration unit with the same structure is connected in parallel with this unit. These two filtration units operate alternately, with one unit operating at a time while the other remains on standby, enabling stable rotational operation.

[0039] Example 2

[0040] A low-energy-consumption desolidification method for catalytic cracking slurry, such as Figure 1 As shown, the catalytic cracking slurry, after heat exchange and without the addition of diluent, is directly subjected to electrostatic separation treatment. The slurry after electrostatic separation treatment is then filtered and desolidified to complete the purification of the slurry. At the same time, the purified slurry after desolidification treatment is used to backwash out the slurry produced by filtration and desolidification. The backwashed slurry and the slurry discharged from electrostatic separation are then mixed with diluent and filtered again to separate the heavy oil slurry and solid particles.

[0041] In this embodiment, the solid content of the catalytic cracking slurry used is 3000 μg / g and the bitumen content is 3.5 wt.%.

[0042] The temperature of the catalytic cracking slurry after heat exchange is 150°C;

[0043] The diluent is n-butane;

[0044] Testing revealed that the asphalt content in the slurry after electrostatic separation treatment was 2.27% before it entered the filtration and desolidification process.

[0045] The electric field in the electrostatic separation process is a pulsed electric field with a field strength of 2000 V / cm.

[0046] The residence time of the catalytic cracking slurry during electrostatic separation is 3 hours.

[0047] During the filtration and desolidification process, the pore size of the filter media used is less than 60 μm;

[0048] During operation, the electric field treatment device operates stably, with the current remaining stable at around 7A. The asphalt content of the catalytic slurry after electric field treatment is reduced to 2.27 wt.%. The slurry filtration device operates stably, reaching a pressure drop of 500 kPa in approximately 12 hours, after which backwashing regeneration is initiated, during which the filter media is regenerated. The slurry filtration device reaches a pressure drop of 500 kPa in approximately 24 hours, after which backwashing regeneration is initiated, during which the filter media is easily regenerated. In this operation, the slurry and slurry filtration devices form a filtration unit, and another filtration unit with the same structure is connected in parallel with this unit. These two filtration units operate alternately, with one unit operating at a time while the other remains on standby, enabling stable rotational operation.

[0049] Example 3

[0050] A low-energy-consumption desolidification method for catalytic cracking slurry, such as Figure 1 As shown, the catalytic cracking slurry, after heat exchange and without the addition of diluent, is directly subjected to electrostatic separation treatment. The slurry after electrostatic separation treatment is then filtered and desolidified to complete the purification of the slurry. At the same time, the purified slurry after desolidification treatment is used to backwash out the slurry produced by filtration and desolidification. The backwashed slurry and the slurry discharged from electrostatic separation are then mixed with diluent and filtered again to separate the heavy oil slurry and solid particles.

[0051] In this embodiment, the solid content of the catalytic cracking slurry used is 3000 μg / g and the bitumen content is 3.5 wt.%.

[0052] The temperature of the catalytic cracking slurry after heat exchange is 200°C;

[0053] The diluent is n-hexane;

[0054] Testing revealed that the asphalt content in the slurry after electrostatic separation treatment was 1.46% before it entered the filtration and desolidification process.

[0055] The electric field in the electrostatic separation process is a DC electric field with a field strength of 3000 V / cm. The residence time of the catalytic cracking slurry during the electrostatic separation process is 2.5 h.

[0056] During the filtration and desolidification process, the filter media used has a pore size of 50 μm.

[0057] During operation, the electric field treatment device operates stably, with the current remaining stable at around 10A. The asphalt content of the catalytic slurry after electric field treatment is reduced to 1.46 wt.%. The slurry filtration device operates stably, reaching a pressure drop of 500 kPa in approximately 24 hours, after which backwashing regeneration is initiated, during which the filter media is regenerated. The slurry filtration device reaches a pressure drop of 500 kPa in approximately 48 hours, after which backwashing regeneration is initiated, during which the filter media is easily regenerated. In this operation, the slurry and slurry filtration devices form a filtration unit, and another filtration unit with the same structure is connected in parallel with this unit. These two filtration units operate alternately, with one unit operating at a time while the other remains on standby, enabling stable rotational operation.

[0058] Example 4

[0059] A low-energy-consumption desolidification method for catalytic cracking slurry, such as Figure 1 As shown, the catalytic cracking slurry, after heat exchange and without the addition of diluent, is directly subjected to electrostatic separation treatment. The slurry after electrostatic separation treatment is then filtered and desolidified to complete the purification of the slurry. At the same time, the purified slurry after desolidification treatment is used to backwash out the slurry produced by filtration and desolidification. The backwashed slurry and the slurry discharged from electrostatic separation are then mixed with diluent and filtered again to separate the heavy oil slurry and solid particles.

[0060] In this embodiment, the solid content of the catalytic cracking slurry used is 3000 μg / g and the bitumen content is 3.5 wt.%.

[0061] The temperature of the catalytic cracking slurry after heat exchange is 250°C;

[0062] The diluent is n-heptane;

[0063] Testing revealed that the asphalt content in the slurry after electrostatic separation treatment was 0.28% before it entered the filtration and desolidification process.

[0064] The electric field in the electrostatic separation process is a DC electric field with a field strength of 8000 V / cm.

[0065] The residence time of the catalytic cracking slurry during electrostatic separation treatment is 2 hours.

[0066] During the filtration and desolidification process, the filter media used has a pore size of 20 μm.

[0067] During operation, the electric field treatment device operates stably, with the current remaining stable at around 15A. The asphalt content of the catalytic slurry after electric field treatment is reduced to 0.28 wt.%. The slurry filtration device operates stably, reaching a pressure drop of 500 kPa in approximately 36 hours, after which backwashing regeneration is initiated, during which the filter media is regenerated. The slurry filtration device reaches a pressure drop of 500 kPa in approximately 64 hours, after which backwashing regeneration is initiated, during which the filter media is easily regenerated. In this operation, the slurry and slurry filtration devices form a filtration unit, and another filtration unit with the same structure is connected in parallel with this unit. These two filtration units operate alternately, with one unit operating at a time while the other remains on standby, enabling stable rotational operation.

[0068] Example 5

[0069] A low-energy-consumption desolidification method for catalytic cracking slurry, such as Figure 1 As shown, the catalytic cracking slurry, after heat exchange and without the addition of diluent, is directly subjected to electrostatic separation treatment. The slurry after electrostatic separation treatment is then filtered and desolidified to complete the purification of the slurry. At the same time, the purified slurry after desolidification treatment is used to backwash out the slurry produced by filtration and desolidification. The backwashed slurry and the slurry discharged from electrostatic separation are then mixed with diluent and filtered again to separate the heavy oil slurry and solid particles.

[0070] In this embodiment, the solid content of the catalytic cracking slurry used is 3000 μg / g and the bitumen content is 3.5 wt.%.

[0071] The temperature of the catalytic cracking slurry after heat exchange is 300°C;

[0072] The diluent is gasoline;

[0073] Testing revealed that the asphalt content in the slurry after electrostatic separation treatment was 0.2% before it entered the filtration and desolidification process.

[0074] The electric field in the electrostatic separation process is a DC electric field with a field strength of 12000 V / cm.

[0075] The residence time of the catalytic cracking slurry during electrostatic separation is 1.5 hours.

[0076] During the filtration and desolidification process, the filter media used has a pore size of 10 μm.

[0077] During operation, the electric field treatment device operates stably, with the current remaining stable at around 20A. The asphalt content of the catalytic slurry after electric field treatment is reduced to 0.2 wt.%. The slurry filtration device operates stably, reaching a pressure drop of 500 kPa in approximately 40 hours, after which backwashing regeneration is initiated, during which the filter media is regenerated. The slurry filtration device reaches a pressure drop of 500 kPa in approximately 70 hours, after which backwashing regeneration is initiated, during which the filter media is easily regenerated. In this operation, the slurry and slurry filtration devices form a filtration unit, and another filtration unit with the same structure is connected in parallel with this unit. These two filtration units operate alternately, with one unit operating at a time while the other remains on standby, enabling stable rotational operation.

[0078] Example 6

[0079] A low-energy-consumption desolidification method for catalytic cracking slurry, such as Figure 1 As shown, the catalytic cracking slurry, after heat exchange and without the addition of diluent, is directly subjected to electrostatic separation treatment. The slurry after electrostatic separation treatment is then filtered and desolidified to complete the purification of the slurry. At the same time, the purified slurry after desolidification treatment is used to backwash out the slurry produced by filtration and desolidification. The backwashed slurry and the slurry discharged from electrostatic separation are then mixed with diluent and filtered again to separate the heavy oil slurry and solid particles.

[0080] In this embodiment, the solid content of the catalytic cracking slurry used is 3000 μg / g and the bitumen content is 3.5 wt.%.

[0081] The temperature of the catalytic cracking slurry after heat exchange is 350°C;

[0082] The diluent is catalytic diesel oil;

[0083] Testing revealed that the asphalt content in the slurry after electrostatic separation treatment was 0.13% before it entered the filtration and desolidification process.

[0084] The electric field in the electrostatic separation process is a DC electric field with a field strength of 15000 V / cm.

[0085] The residence time of the catalytic cracking slurry during electrostatic separation is 1 hour.

[0086] During the filtration and desolidification process, the filter media used has a pore size of 5 μm.

[0087] During operation, the electric field treatment device operates stably, with the current remaining stable at around 30A. The asphalt content of the catalytic slurry after electric field treatment is reduced to 0.13 wt.%. The slurry filtration device operates stably, reaching a pressure drop of 500 kPa in approximately 48 hours, after which backwashing regeneration is initiated, during which the filter media is regenerated. The slurry filtration device reaches a pressure drop of 500 kPa in approximately 78 hours, after which backwashing regeneration is initiated, during which the filter media is easily regenerated. In this operation, the slurry and slurry filtration devices form a filtration unit, and another filtration unit with the same structure is connected in parallel with this unit. These two filtration units operate alternately, with one unit operating at a time while the other remains on standby, enabling stable rotational operation.

[0088] Example 7

[0089] A low-energy desolidification system for catalytic cracking slurry, such as Figure 1 As shown, the device includes an electric field treatment device and an oil slurry filtration device. Catalytic cracking oil slurry without added diluent is directly fed into the electric field treatment device for pretreatment. The pretreated oil slurry then enters the oil slurry filtration device for filtration and desolidification, thus completing the desolidification process. The oil slurry filtration device is equipped with a backwashing system. The slurry automatically discharged from the electric field treatment device and the slurry discharged after backwashing from the oil slurry filtration device are mixed with diluent and then sent to the slurry filtration device for further processing to separate heavy oil slurry and solid particles.

[0090] In this embodiment, the solvent recovery device includes, but is not limited to, distillation and extraction methods to separate the solvent from the oil slurry;

[0091] In this embodiment, the purified slurry outlet of the slurry filtration device is connected to a desolidified slurry collection device, and the desolidified slurry collection device returns the collected purified slurry to the slurry filtration device and the desolidified slurry collection device through a pipeline.

[0092] In this embodiment, the deconsolidated oil slurry collection device is equipped with a backwash oil pipeline. The backwash oil includes, but is not limited to, purified oil slurry in the purified oil slurry collection device, catalytic diesel, diesel, wax oil, and other petroleum distillate oils, one or more of these.

[0093] In this embodiment, the filtrate outlet of the slurry filtration device is connected to a solvent recovery device, and the solvent recovery device mixes the separated solvent with the slurry discharged after backwashing through a pipeline.

[0094] In this embodiment, the slurry filtration device has a backwashing pipeline, and a solvent recovery device is connected to the backwash liquid outlet of the slurry filtration device. The solvent recovery device separates the solvent from the solid particles and mixes the solvent again with the slurry discharged after backwashing through the pipeline.

[0095] In this embodiment, the oil slurry in the desolidified oil slurry collection device serves as the discharge device for the purified oil slurry after desolidification, the heavy oil slurry discharged from the solvent recovery device serves as the discharge device for coking raw materials or fuel, and the solid particles discharged from the solvent recovery device are discharged externally.

[0096] In this embodiment, the oil slurry filtration device and the sludge filtration device form a set of filtration units, and another set of filtration units with the same structure is set in parallel with this set of filtration units. The two sets of filtration units are operated in one and standby at the same time. This means that only one set of filtration units is working at the same time, while the other set is on standby.

[0097] To verify the energy-saving and yield-increasing effects of this invention, the following comparative experiments were conducted:

[0098] Experimental Example 1

[0099] A catalytic slurry with a solid content of 3000 μg / g and an asphalt content of 3.5 wt.% was selected and processed according to the attached... Figure 1 The process involves a desolidification test. The catalytic oil slurry is heated to 200℃ and then subjected to preliminary deasphalting and desolidification treatment in an electric field treatment device with a DC electric field strength of 7000V / cm. The primary purified oil slurry exiting from the top of the electric field treatment device is filtered through a ceramic device with 50μm pores. After electric field treatment and filtration, the purified oil slurry has a solid content of approximately 100μg / g. The slurry discharged from the bottom of the electric field treatment device is mixed with the slurry discharged from the bottom of the oil slurry filtration device and 120# solvent oil, and then enters the slurry filtration device. The resulting heavy oil slurry and 120# solvent oil enter the solvent recovery system to recover the solvent, yielding heavy oil slurry and circulating solvent. The 120# solvent oil and solid particles obtained from backwashing the slurry filtration system enter the solvent recovery system to recover the circulating solvent and solid particles. Both the heavy oil slurry and solid particles exit the device.

[0100] During the experiment, the electric field treatment device operated stably, with the current remaining stable at around 13A. The asphalt content of the catalytic slurry after electric field treatment decreased to 0.28 wt.%. The slurry filtration device operated stably, reaching a pressure drop of 500 kPa in approximately 30 hours, after which backwashing regeneration was initiated. The filter media was regenerated during the backwashing process. Similarly, the slurry filtration device reached a pressure drop of 500 kPa in approximately 60 hours, after which backwashing regeneration was initiated. The filter media was easily regenerated during the backwashing process.

[0101] Tests showed that, under laboratory conditions, the energy consumption for processing 1 ton of catalytic oil slurry was 628.65 MJ / ton of raw material, and the yield of purified oil slurry was 82.5%.

[0102] Comparative Example 1

[0103] A catalytic slurry with a solid content of 3000 μg / g and an asphalt content of 3.5 wt.% was selected and processed according to the attached... Figure 2 The solidification test was conducted using the same process. The catalytic oil slurry was heated to 200℃, then mixed with 120# solvent oil at a 1:1 ratio and fed into an electric field treatment device with a DC electric field strength of 7000V / cm for preliminary deasphalting and solidification treatment. The primary purified oil slurry exiting from the top of the electric field treatment device was filtered through a ceramic device with 50μm pores. After electric field treatment and filtration, the solid content of the purified oil slurry was approximately 130μg / g. The treatment methods for the slurry discharged from the bottom of the electric field treatment device and the slurry discharged from the bottom of the oil slurry filtration device were the same as in Experimental Example 1.

[0104] During the experiment, the electric field treatment device was able to operate smoothly, and the current was able to remain stable at around 9A.

[0105] Tests showed that, under laboratory conditions, the energy consumption for processing 1 ton of catalytic oil slurry was 871.27 MJ / ton of raw material, and the yield of purified oil slurry was 65.1%.

[0106] Experiment Example 2

[0107] A catalytic slurry with a solid content of 3000 μg / g and an asphalt content of 3.5 wt.% was selected for desolidification experiments. The catalytic slurry was heated to 200℃ and subjected to preliminary deasphalting and desolidification treatment in an electric field treatment device with a DC electric field strength of 10000 V / cm. The primary purified slurry exiting from the upper part of the electric field treatment device was filtered through a ceramic device with 50 μm pores. After electric field treatment and filtration, the purified slurry had a solid content of approximately 70 μg / g. The slurry discharged from the bottom of the electric field treatment device, along with the slurry discharged from the bottom of the slurry filtration device and 120# solvent oil, was mixed and then entered into a slurry filtration device. The resulting heavy slurry and 120# solvent oil entered a solvent recovery system to recover the solvent, yielding heavy slurry and circulating solvent. The 120# solvent oil and solid particles obtained from backwashing the slurry filtration system entered the solvent recovery system to recover the circulating solvent and solid particles. Both the heavy slurry and solid particles exited the device.

[0108] During the experiment, the electric field treatment device operated stably, with the current remaining stable at around 18A. The asphalt content of the catalytic slurry after electric field treatment decreased to 0.1 wt.%. The slurry filtration device operated stably, reaching a pressure drop of 500 kPa in approximately 35 hours, after which backwashing regeneration was initiated. The filter media was easily regenerated during the backwashing process. Similarly, the slurry filtration device reached a pressure drop of 500 kPa in approximately 65 hours, after which backwashing regeneration was initiated. The filter media was also easily regenerated during the backwashing process.

[0109] Tests showed that, under laboratory conditions, the energy consumption for processing 1 ton of catalytic oil slurry was 634.25 MJ / ton of raw material, and the yield of purified oil slurry was 87.5%.

[0110] Comparative Example 2

[0111] A catalytic slurry with a solid content of 3000 μg / g and an asphalt content of 3.5 wt.% was selected and processed according to the attached... Figure 2 The solidification test was conducted using the same process. The catalytic oil slurry was heated to 200℃, then mixed with 120# solvent oil in a 1:1 ratio and fed into an electric field treatment device with a DC electric field strength of 10000V / cm for preliminary deasphalting and solidification treatment. The primary purified oil slurry exiting from the top of the electric field treatment device was filtered through a ceramic device with 50μm pores. After electric field treatment and filtration, the solid content of the purified oil slurry was approximately 85μg / g. The treatment methods for the slurry discharged from the bottom of the electric field treatment device and the slurry discharged from the bottom of the oil slurry filtration device were the same as in Experiment 2.

[0112] During the experiment, the electric field treatment device was able to operate smoothly, and the current was able to remain stable at around 14A.

[0113] Tests showed that, under laboratory conditions, the energy consumption for processing 1 ton of catalytic oil slurry was 875.27 MJ / ton of raw material, and the yield of purified oil slurry was 65.8%.

[0114] Experimental Example 3

[0115] A catalytic slurry with a solid content of 3000 μg / g and an asphalt content of 3.5 wt.% was selected for desolidification experiments. The catalytic slurry was heated to 200℃ and subjected to preliminary deasphalting and desolidification treatment in an electric field treatment device with a DC electric field strength of 15000 V / cm. The primary purified slurry exiting from the upper part of the electric field treatment device was filtered through a ceramic device with 50 μm pores. After electric field treatment and filtration, the purified slurry had a solid content of approximately 50 μg / g. The slurry discharged from the bottom of the electric field treatment device, along with the slurry discharged from the bottom of the slurry filtration device and 120# solvent oil, was mixed and then entered into a slurry filtration device. The resulting heavy slurry and 120# solvent oil entered a solvent recovery system to recover the solvent, yielding heavy slurry and circulating solvent. The 120# solvent oil and solid particles obtained from backwashing the slurry filtration system entered the solvent recovery system to recover the circulating solvent and solid particles. Both the heavy slurry and solid particles exited the device.

[0116] During the experiment, the electric field treatment device operated stably, with the current remaining stable at around 25A. The asphalt content of the catalytic slurry after electric field treatment decreased to 0.02 wt.%. The slurry filtration device operated stably, reaching a pressure drop of 500 kPa in approximately 48 hours, after which backwashing regeneration was initiated. The filter media was easily regenerated during the backwashing process. The slurry filtration device operated stably, reaching a pressure drop of 500 kPa in approximately 70 hours, after which backwashing regeneration was initiated. The filter media was easily regenerated during the backwashing process.

[0117] Tests showed that, under laboratory conditions, the energy consumption for processing 1 ton of catalytic oil slurry was 639.25 MJ / ton of raw material, and the yield of purified oil slurry was 89.1%.

[0118] Comparative Example 3

[0119] A catalytic slurry with a solid content of 3000 μg / g and an asphalt content of 3.5 wt.% was selected and processed according to the attached... Figure 2 The solidification test was conducted using the same process. The catalytic oil slurry was heated to 200℃, then mixed with diluted diesel oil at a 1:1 ratio and fed into an electric field treatment device with a DC electric field strength of 15000V / cm for preliminary deasphalting and solidification treatment. The primary purified oil slurry exiting from the top of the electric field treatment device entered a ceramic device with 50μm pore size for filtration. After electric field treatment and filtration, the solid content of the purified oil slurry was approximately 55μg / g. The treatment methods for the slurry discharged from the bottom of the electric field treatment device and the slurry discharged from the bottom of the oil slurry filtration device were the same as in Experiment 3.

[0120] During the experiment, the electric field treatment device was able to operate smoothly, and the current was able to remain stable at around 18A.

[0121] Tests showed that, under laboratory conditions, the energy consumption for processing 1 ton of catalytic oil slurry was 881.37 MJ / ton of raw material, and the yield of purified oil slurry was 67.2%.

[0122] The comparison of the results in the experimental examples and the comparative examples shows that, under the same electric field strength and processing time, the energy consumption of Experimental Example 1-3 for processing the same mass and quality of catalytic oil slurry is much lower than that of Comparative Example 1-3, while the yield of Experimental Example 1-3 is significantly greater than that of Comparative Example 1-3.

Claims

1. A low-energy-consumption desolidification method for catalytic cracking slurry, characterized in that: The catalytic cracking slurry, after heat exchange and without the addition of diluent, is directly subjected to electrostatic separation. The slurry after electrostatic separation is then filtered for solidification to complete the purification. The temperature of the catalytic cracking slurry after heat exchange is 100-350℃. During the electrostatic separation, the electric field strength is 500-15000V / cm. The residence time of the catalytic cracking slurry during electrostatic separation is less than 4 hours. Before entering the filtration and solidification process, the asphalt content in the slurry is less than 1%. The pore size of the filter packing used in the filtration and solidification process is less than 100μm. Simultaneously, the purified slurry after solidification is backwashed to remove the slurry produced by filtration and solidification. The backwashed slurry, the slurry discharged from electrostatic separation, and the diluent are then mixed and filtered again to separate the heavy oil slurry and solid particles.

2. The low-energy-consumption desolidification method for catalytic cracking slurry according to claim 1, characterized in that: The temperature of the catalytic cracking slurry after heat exchange is 100-250℃.

3. The low-energy-consumption desolidification method for catalytic cracking slurry according to claim 2, characterized in that: The temperature of the catalytic cracking slurry after heat exchange is 150-250℃.

4. The low-energy-consumption desolidification method for catalytic cracking slurry according to claim 1, characterized in that: Before the slurry undergoing electrostatic separation treatment enters the filtration and desolidification process, the asphalt content in the slurry is less than 0.5%.

5. A low-energy-consumption desolidification method for catalytic cracking slurry according to claim 4, characterized in that: Before the slurry undergoing electrostatic separation treatment enters the filtration and desolidification process, the asphalt content in the slurry is less than 0.2%.

6. The low-energy-consumption desolidification method for catalytic cracking slurry according to claim 1, characterized in that: The electric field in the electrostatic separation process is an alternating electric field, a direct current electric field, or a pulsed electric field.

7. A low-energy-consumption desolidification method for catalytic cracking slurry according to claim 6, characterized in that: The electric field in the electrostatic separation process is a DC electric field or a pulsed electric field.

8. A low-energy-consumption desolidification method for catalytic cracking slurry according to claim 1, characterized in that: During the electrostatic separation process, the electric field strength is 2000-15000V / cm.

9. A low-energy-consumption desolidification method for catalytic cracking slurry according to claim 8, characterized in that: During the electrostatic separation process, the electric field strength is 3000-8000V / cm.

10. A low-energy-consumption desolidification method for catalytic cracking slurry according to claim 1, characterized in that: The residence time of the catalytic cracking slurry during electrostatic separation is less than 2 hours.

11. A low-energy-consumption desolidification method for catalytic cracking slurry according to claim 1, characterized in that: During the filtration and desolidification process, the pore size of the filter packing material used is less than 20 μm.

12. A low-energy-consumption desolidification method for catalytic cracking slurry according to claim 11, characterized in that: During the filtration and desolidification process, the pore size of the filter packing material used is less than 5 μm.

13. A low-energy-consumption desolidification method for catalytic cracking slurry according to claim 1, characterized in that: The conditions for backwashing and filtering the slurry generated by the desolidification process using the purified oil slurry after desolidification are as follows: the pressure difference before and after the filter device is 100-600 kPa, or the filtration time is 12-72 h, or the frequency of regular cleaning is 7-30 days / time.

14. The low-energy-consumption desolidification method for catalytic cracking slurry according to claim 1, characterized in that: After the two types of slurry are mixed with the diluent, they are filtered again and then the solvent needs to be recovered.

15. A low-energy-consumption desolidification system for catalytic cracking slurry, comprising an electric field treatment device and a slurry filtration device, characterized in that: Catalytic cracking slurry without added diluent is directly fed into an electric field treatment device for pretreatment. The pretreated slurry then enters a slurry filtration device for filtration and desolidification, thus completing the desolidification process. The slurry filtration device is equipped with a backwashing system. The slurry automatically discharged from the electric field treatment device and the slurry discharged after backwashing from the slurry filtration device are mixed with diluent and then sent to the slurry filtration device for further processing to separate heavy oil slurry and solid particles.

16. A low-energy-consumption desolidification system for catalytic cracking slurry according to claim 15, characterized in that: The purified slurry outlet of the slurry filtration device is connected to a desolidified slurry collection device, and the desolidified slurry collection device returns the collected purified slurry to the slurry filtration device and the desolidified slurry collection device through a pipeline.

17. A low-energy-consumption desolidification system for catalytic cracking slurry according to claim 16, characterized in that: The desolidified oil slurry collection device is equipped with a backwashing oil pipeline.

18. A low-energy-consumption desolidification system for catalytic cracking slurry according to claim 15, characterized in that: The filtrate outlet of the slurry filtration device is connected to a solvent recovery device, and the solvent recovery device mixes the separated solvent with the slurry discharged after backwashing through a pipeline.

19. A low-energy-consumption desolidification system for catalytic cracking slurry according to claim 15, characterized in that: The slurry filtration device has a backwashing pipeline, and a solvent recovery device is connected to the backwash liquid outlet of the slurry filtration device. The solvent recovery device separates the solvent from the solid particles and mixes the solvent again with the slurry discharged after backwashing through the pipeline.

20. A low-energy-consumption desolidification system for catalytic cracking slurry according to claim 15, characterized in that: The oil slurry filtration device and the slurry filtration device form a set of filtration units, and another set of filtration units with the same structure is set in parallel with this set of filtration units. The two sets of filtration units are operated in one and standby in the other.

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