A liquid hydrocarbon filtration system and filtration method

Abstract

The application discloses a liquid hydrocarbon filtering system and filtering method, and provides the liquid hydrocarbon filtering system, which comprises a filtering unit and a regeneration unit, the filter of the filtering unit is provided with at least one filtering assembly and at least one forward pressure feeding assembly, the regeneration unit is provided with a back flushing gas tank and a pressure feeding gas tank, the back flushing gas tank is connected with an oil outlet pipeline after filtering and a forward pressure feeding oil outlet pipeline through pipelines, and the pressure feeding gas tank is connected with a top inlet of the filter through a pipeline. The application adopts the filtering mode, the forward pressure feeding mode, the slag discharging mode, the blowing mode and the next filtering mode, forward pressure feeding mode, slag discharging mode and blowing mode which are alternately operated, so that the oil yield after filtering is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of liquid hydrocarbon filtration, in particular to a liquid hydrocarbon filtration system and a filtration method. BACKGROUND

[0002] Catalytic cracking is an important process technology for producing gasoline and diesel from heavy oil, and is one of the most important and widely used technologies in the field of oil refining at present. However, catalytic cracking produces oil slurry as a byproduct. In particular, at present, catalytic cracking mostly uses hydrogenated residual oil or residual oil blended with wax oil as a raw material, and the oil slurry yield is relatively high, generally about 5%, and even as high as 8% in some cases. The oil slurry is rich in polycyclic aromatic hydrocarbons, which can be used as a raw material for producing ship fuel or carbon black, carbon fiber, etc. However, due to the presence of 1-6 g / L of catalytic cracking catalyst particles in the oil slurry, it cannot meet the requirements of the raw material indicators for producing ship fuel or carbon black, carbon fiber, etc., and therefore has relatively low utilization value at present.

[0003] In order to improve the utilization value of the oil slurry, the solid particles in the oil slurry must be removed first. There are various methods for removing solid particles, such as sedimentation, flocculation, centrifugation, etc. However, the removal efficiency of these methods is too low, and filtration is a better method for removing solid particles from the oil slurry. The filtration process is divided into blind end filtration and cross flow filtration according to the difference in fluid and separation direction. In the blind end filtration process, a single filter is generally operated intermittently, and when the pressure drop of the filter reaches a certain value or a certain time is reached, the oil slurry in the filter needs to be discharged, and the filter material needs to be regenerated so that the filtration area of the filter material can be restored to the original amount. The amount of slurry discharged from the filter directly affects the desolid product yield of the filtration process. In the case of the same amount of feed in the same time, the greater the amount of slurry discharged, the lower the desolid product yield. Once the filter equipment is determined, the desolid product yield is basically fixed.

[0004] CN111592908A discloses an oil slurry filtration system and an oil slurry filtration method, wherein at least one filter is provided in the filtration unit, and the used filter is back-flushed with a purge medium, which is an inert gas and / or a flushing oil, and the flushing oil is filtered oil. A filter bag made of flexible filter material without pinholes is provided in the filter.

[0005] CN111592909A discloses an oil slurry filtration system and an oil slurry filtration method, which includes a filtration unit and a filter aid buffer tank. At least one filter is provided in the filtration unit, and an oil slurry inlet pipeline, a filtered oil outlet pipeline, and a filter residue discharge pipeline are respectively communicated with each filter. The outlet of the filter aid buffer tank is communicated with the oil slurry inlet of the filter. A filter bag made of flexible filter material without pinholes is provided in the filter. In the oil slurry filtration method, the oil slurry enters the filter through the oil slurry inlet pipeline communicated with the filter for filtration, and the filtered oil is extracted from the filtered oil outlet pipeline.

[0006] The prior art focuses on the effectiveness of the filtration system and the stability of the filtered product. SUMMARY

[0007] The present application aims to solve the problem of low filtered oil yield in the prior art, and provides a liquid hydrocarbon filtration system and a filtration method.

[0008] The first aspect of the present application provides a liquid hydrocarbon filtration system, wherein a filter is arranged in the filtration unit, the filter has at least one filtration assembly and at least one forward pressure assembly, a liquid hydrocarbon inlet is arranged at the lower part of the filter, a filtered oil outlet and a forward pressure oil outlet are arranged at the upper part of the filter, a filter residue outlet is arranged at the bottom of the filter, a pressure gas inlet is arranged at the top of the filter, and a liquid hydrocarbon inlet pipeline, a filtered oil outlet pipeline, a forward pressure oil outlet pipeline, a filter residue discharge pipeline and a pressure gas inlet pipeline are respectively communicated with each filter,

[0009] The filtration assembly is arranged from inside to outside as a center pipe I, a support pipe I and a flexible filter material, the wall of the center pipe I is not perforated, the wall of the support pipe I is uniformly perforated, the upper end and the lower end of the support pipe I are respectively provided with a first tuning fork liquid level meter switch and a second tuning fork liquid level meter switch, and the forward pressure assembly is arranged from inside to outside as a center pipe II, a support pipe II and a flexible filter material, the wall of the center pipe II is not perforated, the upper wall of the support pipe II is not perforated, the lower wall of the support pipe II is uniformly perforated, and the upper end and the lower end of the non-perforated part of the support pipe II are respectively provided with a third tuning fork liquid level meter switch and a fourth tuning fork liquid level meter switch.

[0010] The regeneration unit is provided with a backblowing gas tank and a pressure gas tank, the backblowing gas tank outlet pipeline is communicated with the filtered oil outlet pipeline, and the backblowing gas tank outlet pipeline is communicated with the forward pressure oil outlet pipeline, and the pressure gas tank outlet pipeline is communicated with the pressure gas inlet at the top of the filter.

[0011] In an embodiment of the present application, in the filtration assembly, the diameter ratio of the center pipe I to the support pipe I is in the range of 1:2 to 1:6, the distance between the end bottom of the center pipe I and the end bottom of the support pipe I is 0.2m to 0.8m, and the perforation rate of the wall of the support pipe I is 55% to 85%.

[0012] In an embodiment of the present application, in the forward pressure assembly, the diameter ratio of the center pipe II to the support pipe II is in the range of 1:2 to 1:6, the distance between the end bottom of the center pipe II and the end bottom of the support pipe II is 0.2m to 0.8m, the perforation rate of the perforated part of the wall of the support pipe II is 55% to 85%, and the height of the perforated part of the wall of the support pipe II is 1 / 2 to 1 / 3 of the total height of the support pipe II.

[0013] In one embodiment of the present application, the horizontal positions of the first tuning fork liquid level meter switch and the third tuning fork liquid level meter switch are identical.

[0014] In one embodiment of the present application, the flexible filter material is fixed to the outer surface of the support tube I by the upper and lower end caps.

[0015] In one embodiment of the present application, the flexible filter material is fixed to the outer surface of the support tube II by the upper and lower end caps.

[0016] In one embodiment of the present application, the flexible filter material is selected from one or more of polyethylene, nylon, polyphenylene sulfide, polyimide, polytetrafluoroethylene, aramid, polyurethane, and glass fiber.

[0017] In one embodiment of the present application, the flexible filter material is a composite of two or more selected from polyethylene, nylon, polyphenylene sulfide, polyimide, polytetrafluoroethylene, aramid, polyurethane, and glass fiber.

[0018] In one embodiment of the present application, the flexible filter material has a filtration accuracy of 0.1 to 15 microns, preferably 0.1 to 10 microns, and more preferably 0.2 to 5 microns. The flexible filter material has a grammage of 300 to 1000 g / m 2 , preferably 520 to 660 g / m 2 ; a warp breaking strength of 850 N / 5 cm to 9000 N / 5 cm and a weft breaking strength of 1000 N / 5 cm to 11000 N / 5 cm; and a thickness of 0.5 to 3.4 mm, preferably 0.5 to 3.0 mm, and more preferably 1.8 to 2.9 mm.

[0019] In one embodiment of the present application, the flexible filter material in the filter of the present application can be single-layered (single) or multi-layered (two or more). When multi-layered, the multi-layered flexible filter material is stacked, and in this case, the number of layers and the arrangement between the layers are not limited.

[0020] In one embodiment of the present application, the flexible filter material includes a desolid layer having a porosity of 25% to 98% and a base cloth layer having a porosity of 30% to 40%, the base cloth layer being made of polytetrafluoroethylene and / or polyphenylene sulfide, and the desolid layer being made of polytetrafluoroethylene.

[0021] The base cloth layer is obtained by weaving the above-mentioned raw material capable of being made into a flexible filter material using a weaving technique known in the art. The weaving technique is not limited in any way, including but not limited to water jet method, heat sealing method, wet weaving method, spun-bonding method, melt-blowing method, needle punching method, sewing method, hot rolling method, etc. The desolidification layer is formed on the base cloth layer by a method known in the art, such as hot pressing method, film coating method, hot rolling method, etc., using the above-mentioned raw material capable of being made into a flexible filter material. The desolidification layer and the base cloth layer of the present application can be prepared independently in sequence, or can be prepared integrally. The flexible filter material of the present application comprising at least the desolidification layer and the base cloth layer can be prepared by a method known in the art, or can be a commercially available product.

[0022] In one embodiment of the present application, the flexible filter material comprises at least the desolidification layer and the base cloth layer, but is not limited thereto, and can be changed and derived therefrom. For example, on the basis of the desolidification layer and the base cloth layer of the present application, other layers can be further included without adversely affecting the effects of the present application.

[0023] In one embodiment of the present application, the blowback gas in the blowback gas tank is nitrogen and / or fuel gas.

[0024] In one embodiment of the present application, the pressurizing gas in the pressurizing gas tank is nitrogen and / or fuel gas.

[0025] In one embodiment of the present application, the liquid hydrocarbon is catalytic cracking slurry oil and / or coal tar.

[0026] The present inventors have found through a large amount of research that when the filter pressure drop or the filtration time reaches a certain value, at this time the oil slurry level in the filter is higher than the filtration assembly, and if the regeneration mode of discharging the residue is directly used, the part of the oil slurry in the filter will be lost. Although the filter material (flexible filter material) still has a certain flux, the filter cake on the outer surface of the flexible filter material is uneven, and by passing the gas into the filter top to positively pressurize, only the oil slurry above the top end of the pressurizing assembly can be recovered.

[0027] Therefore, the present application provides a positive pressurizing assembly, and by passing the pressurizing gas of a certain pressure from the top of the filter, the liquid hydrocarbon higher than the top end of the pressurizing assembly is pressed out through the positive pressurizing assembly, and this part of the positively pressurized oil is mixed with the filtered oil. In the present application, the positively pressurized oil refers to the liquid hydrocarbon in the filter which is pressed out by the pressurizing gas in the positive pressurizing mode.

[0028] The second aspect of the present application provides a liquid hydrocarbon filtration method using the above filtration system, comprising: a filtration mode: the liquid hydrocarbon inlet and the filtered oil outlet of the filter are in an open state, and other inlets and outlets of the filter are in a closed state, after the liquid hydrocarbon enters the filter from the liquid hydrocarbon inlet pipeline, the liquid hydrocarbon flows from the bottom to the top of the center pipe I of the filter assembly, and the filtered oil is discharged from the top of the center pipe I, and the filtered oil is extracted from the filtered oil outlet of the filter;

[0029] A forward pressure mode: the pressure gas inlet of the filter and the forward pressure oil outlet of the filter are in an open state, and other inlets and outlets of the filter are in a closed state, the pressure gas enters the forward pressure assembly of the filter from the pressure gas inlet, the liquid hydrocarbon stored in the filter is pressed out from the forward pressure oil outlet of the filter, and is mixed with the filtered oil;

[0030] A residue discharge mode: the residue outlet of the filter is in an open state, and other inlets and outlets of the filter are in a closed state, the residual liquid hydrocarbon in the filter is discharged;

[0031] A purge mode: the residue outlet of the filter is in an open state, and the backflush gas enters the filter from the filtered oil outlet pipeline and the forward pressure oil outlet pipeline for purging, after the backflush gas flows from the top to the bottom of the center pipe I of the filter assembly and is discharged, the inner surface of the flexible filter material is purged, and after the backflush gas flows from the top to the bottom of the center pipe II of the forward pressure assembly and is discharged, the inner surface of the flexible filter material is purged.

[0032] In an embodiment of the present application, the liquid hydrocarbon is catalytic cracking slurry oil and / or coal tar.

[0033] In an embodiment of the present application, in the filtration mode, the filtration temperature in the filter is 30-250°C, preferably 60-180°C.

[0034] In an embodiment of the present application, in the filtration mode, the differential pressure in use of the filter is 0.01-0.5 MPa.

[0035] In an embodiment of the present application, in the filtration mode, the filter is set to a filtration time of 24-96 h.

[0036] In one embodiment of the present application, when the pressure difference of the filter reaches or is higher than the pressure difference set value, or reaches the set time, the filter is switched to the forward pressure feeding mode operation in the filtering mode; the filtering mode ends and the forward pressure feeding mode starts, at this time the liquid hydrocarbon liquid level in the filter is higher than the first tuning fork liquid level meter switch, when the liquid hydrocarbon liquid level in the filter is lowered to the fourth tuning fork liquid level meter switch, the forward pressure feeding mode stops and is switched to the residue discharging mode. In this way, the situation that the pressure feeding gas directly enters the rear oil pipeline after filtration when the liquid hydrocarbon liquid level is lower than the top of the filtration assembly, affecting the operation of the filtration system, is avoided, and the yield of the filtered oil is improved.

[0037] The forward pressure feeding mode provided in the present application reduces the amount of liquid hydrocarbon discharged to the filter residue outlet during regeneration, and improves the yield of the filtered oil.

[0038] In one embodiment of the present application, when one filter is provided in the filtration unit, the filtration mode, the forward pressure feeding mode, the residue discharging mode, the purging mode, and the next round of filtration mode, forward pressure feeding mode, residue discharging mode, and purging mode are alternately operated.

[0039] In the present application, one filter can be provided in the filtration unit, or more than two filters can be provided. When multiple filters are provided, the present application does not limit any connection mode. Multiple filters can be provided in parallel, or in series, or in parallel and series switching mode, or in parallel and series simultaneous use mode. When multiple filters are provided, multiple filters with consistent filtration precision can be used, or multiple filters with inconsistent filtration precision can be used.

[0040] In one embodiment of the present application, when multiple filters are provided in the filtration unit, when the pressure difference of an online filter reaches or is higher than the pressure difference set value, or reaches the set time, the filter is cut out of the filtration system, and the forward pressure feeding mode, the residue discharging mode, and the purging mode are used for regeneration operation.

[0041] Compared with the prior art, the liquid hydrocarbon filtration system and the filtration method provided by the present application can significantly improve the yield of the filtered oil slurry and save the filtration cost. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a schematic diagram of one embodiment of the liquid hydrocarbon filtration system provided by the present application.

[0043] Figure 2 is a schematic diagram of another embodiment of the liquid hydrocarbon filtration system provided by the present application.

[0044] Figure 3 This is a schematic diagram of the material flow direction in the filtration mode of the filtration component in the liquid hydrocarbon filtration method provided by the present invention.

[0045] Figure 4 This is a schematic diagram of the material flow direction in the purging mode of the filter component in the liquid hydrocarbon filtration method provided by the present invention.

[0046] Figure 5 This is a schematic diagram of the material flow direction in the forward pressing mode of the forward pressing component in the liquid hydrocarbon filtration method provided by the present invention. Detailed Implementation

[0047] The present invention will be further described below with reference to the accompanying drawings, but this description is not intended to limit the scope of the invention.

[0048] Figure 1 This is a schematic diagram of one embodiment of the liquid hydrocarbon filtration system provided by the present invention, as shown below. Figure 1 As shown, the liquid hydrocarbon filtration system provided by the present invention includes a filtration unit and a regeneration unit. The filtration unit is equipped with a filter 1, and the filter 1 is equipped with a filtration component 2 and a positive pressure component 3. A liquid hydrocarbon inlet is provided at the lower part of the filter 1, a filtered oil outlet and a positive pressure oil outlet are provided at the upper part of the filter 1, a filter residue outlet is provided at the bottom of the filter 1, a pressure gas inlet is provided at the top of the filter 1, and a liquid hydrocarbon inlet pipeline 4, a filtered oil outlet pipeline 5, a positive pressure oil outlet pipeline 14, a filter residue discharge pipeline 6, and a pressure gas inlet pipeline 8 are connected to the filter 1. The filter assembly 2 consists of a central tube I, a support tube I, and a flexible filter material arranged sequentially from the inside out. The central tube I has no holes in its wall, while the support tube I has evenly spaced holes in its wall. The upper and lower ends of the support tube I are respectively equipped with a first tuning fork level switch 9 and a second tuning fork level switch 10. The positive pressing assembly 3 consists of a central tube II, a support tube II, and a flexible filter material arranged sequentially from the inside out. The central tube II has no holes in its wall, while the upper part of the support tube II has no holes, and the lower part of its wall has evenly spaced holes. The upper and lower ends of the non-perforated part of the support tube II are respectively equipped with a third tuning fork level switch 15 and a fourth tuning fork level switch 16. The first tuning fork level switch 9 and the third tuning fork level switch 15 are at the same horizontal position. The regeneration unit is equipped with a backflush gas tank 11 and a pressurizing gas tank 7. The outlet pipeline 12 of the backflush gas tank 11 is connected to the filtered oil outlet pipeline 5, and the outlet pipeline 13 of the backflush gas tank is connected to the forward pressurizing oil outlet pipeline 14. The outlet pipeline 8 of the pressurizing gas tank is connected to the pressurizing gas inlet at the top of the filter 1.

[0049] Figure 2 This is a schematic diagram of one embodiment of the liquid hydrocarbon filtration system provided by the present invention, as shown below. Figure 2As shown, the liquid hydrocarbon filtering system provided by the present application comprises a filtering unit and a regeneration unit, the filtering unit is provided with a filter 1, a filter 4, a liquid hydrocarbon inlet arranged at the lower part of the filter 1 and the filter 4, a filtered oil outlet and a forward pressure oil outlet arranged at the upper part of the filter 1 and the filter 4, a pressure gas inlet arranged at the top of the filter 1 and the filter 4, a residue outlet arranged at the bottom of the filter 1 and the filter 4, and a liquid hydrocarbon inlet pipeline 7, a filtered oil outlet pipeline 9, a residue discharge pipeline 29, a pressure gas pipeline 19 and a forward pressure oil outlet pipeline 11 communicated with the filter 1, and a liquid hydrocarbon inlet pipeline 8, a filtered oil outlet pipeline 10, a residue discharge pipeline 30, a pressure gas pipeline 20 and a forward pressure oil outlet pipeline 12 communicated with the filter 4.

[0050] The filter 1 is provided with a filtering assembly 2 and a forward pressure assembly 3, and the filter 4 is provided with a filtering assembly 5 and a forward pressure assembly 6. The filtering assembly 2 and the filtering assembly 5 are sequentially provided with a center pipe I, a support pipe I and a flexible filter material from inside to outside, the upper end and the lower end of the support pipe I of the filtering assembly 2 are respectively provided with a first tuning fork liquid level meter switch 21 and a second tuning fork liquid level meter switch 22, and the upper end and the lower end of the support pipe I of the filtering assembly 5 are respectively provided with a first tuning fork liquid level meter switch 25 and a second tuning fork liquid level meter switch 26. The forward pressure assembly 3 and the forward pressure assembly 6 are sequentially provided with a center pipe II, a support pipe II and a flexible filter material from inside to outside, the pipe wall of the center pipe II is not provided with a hole, the upper pipe wall of the support pipe II is not provided with a hole, and the lower pipe wall of the support pipe II is uniformly provided with a hole, the upper end and the lower end of the non-hole part of the support pipe II of the forward pressure assembly 3 are respectively provided with a third tuning fork liquid level meter switch 23 and a fourth tuning fork liquid level meter switch 24, and the upper end and the lower end of the non-hole part of the support pipe II of the forward pressure assembly 6 are respectively provided with a third tuning fork liquid level meter switch 27 and a fourth tuning fork liquid level meter switch 28. Among them, the horizontal positions of the first tuning fork liquid level meter switch 21 and the third tuning fork liquid level meter switch 23 are consistent, and the horizontal positions of the first tuning fork liquid level meter switch 25 and the third tuning fork liquid level meter switch 27 are consistent.

[0051] The regeneration unit is provided with a pressure gas tank 14 and a back flushing gas tank 13, the outlet of the pressure gas tank 14 is communicated with the pressure gas inlet at the top of the filter 1 through a pressure gas inlet pipeline 19, and the outlet of the pressure gas tank 14 is communicated with the pressure gas inlet at the top of the filter 4 through a pressure gas inlet pipeline 20. The outlet of the back flushing gas tank 13 is communicated with the filtered oil outlet pipeline 9 of the filter 1 through a pipeline 15, and the outlet of the back flushing gas tank 13 is communicated with the forward pressure oil outlet pipeline 11 of the filter 1 through a pipeline 16; the back flushing gas tank 13 is communicated with the filtered oil outlet pipeline 10 of the filter 4 through a pipeline 17, and the outlet of the back flushing gas tank 13 is communicated with the forward pressure oil outlet pipeline 12 of the filter 4 through a pipeline 18.

[0052] As shown in the figure, the filtering unit is provided with a filter 1, a filter 4, a liquid hydrocarbon inlet arranged at the lower part of the filter 1 and the filter 4, a filtered oil outlet and a forward pressure oil outlet arranged at the upper part of the filter 1 and the filter 4, a pressure gas inlet arranged at the top of the filter 1 and the filter 4, a residue outlet arranged at the bottom of the filter 1 and the filter 4, and a liquid hydrocarbon inlet pipeline 7, a filtered oil outlet pipeline 9, a residue discharge pipeline 29, a pressure gas pipeline 19 and a forward pressure oil outlet pipeline 11 communicated with the filter 1, and a liquid hydrocarbon inlet pipeline 8, a filtered oil outlet pipeline 10, a residue discharge pipeline 30, a pressure gas pipeline 20 and a forward pressure oil outlet pipeline 12 communicated with the filter 4. Figure 2When the filter system shown is filtering, filter 1 and filter 4 can be used in parallel or switched. When switched, filter 1 is online filtering, filter 4 is simultaneously regenerated or in standby state; or filter 4 is online filtering, filter 1 is simultaneously regenerated or in standby state.

[0053] Figure 3 is a schematic diagram of the material flow direction in the filter mode of the filter assembly in the liquid hydrocarbon filtration method provided by the present application. As shown in Figure 3 the filter assembly includes center pipe I 22 and support pipe I 21 covered by flexible filter material. In the filter mode, after the liquid hydrocarbon enters the filter from the liquid hydrocarbon inlet pipeline, the liquid hydrocarbon outside the filter assembly enters the support pipe I 21 covered by flexible filter material in the filter assembly in the directions shown by material flow 23 and material flow 24, the filtered oil then flows from the bottom to the top of the center pipe I 22, and is discharged from the top of the center pipe I 22 as filtered oil 25, which is then extracted from the filtered oil outlet of the filter.

[0054] Figure 4 is a schematic diagram of the material flow direction in the blowdown mode of the filter assembly in the liquid hydrocarbon filtration method provided by the present application. As shown in Figure 4 the filter assembly includes center pipe I 22 and support pipe I 21 covered by flexible filter material. In the blowdown mode, the backflush gas enters the filter from the filtered oil outlet pipeline for blowdown, the backflush gas 26 enters from the top of the center pipe I 22 of the filter assembly, flows from top to bottom, and is discharged from the bottom, and then blows into the inner surface of the flexible filter material covering the outside of the support pipe I, so that the filter cake on the outer surface of the flexible filter material falls off in the directions of material flow 27 and material flow 28.

[0055] Figure 5 is a schematic diagram of the material flow direction in the forward pressure feed mode of the forward pressure feed assembly in the liquid hydrocarbon filtration method provided by the present application. As shown in Figure 5 the forward pressure feed assembly includes center pipe II 30 and support pipe II 29 covered by flexible filter material. In the forward pressure feed mode, the pressure feed gas enters the filter from the pressure feed gas inlet, and the liquid hydrocarbon stored in the filter is pressed into the support pipe II 29 covered by flexible filter material in the forward pressure feed assembly in the directions shown by material flow 31 and material flow 32, and the forward pressure feed oil then flows from the bottom to the top of the center pipe II 30, and is discharged from the top of the center pipe II 30 as forward pressure feed oil 33.

[0056] The present application will be further described in conjunction with the following examples, but the present application is not limited in any way by the examples.

[0057] The properties of the liquid hydrocarbon raw materials used in the examples are listed in Table 1.

[0058] Table 1

[0059] Oil slurry A Oil slurry B Coal tar Density (g / cm 3 )]]> 1.0756 1.0876 1.08 100 °C viscosity (mm 2 / s) 21.88 20.0 2.3 Ash content (pg / g) 4360 1640 2650

[0060] Example 1

[0061] This example employs Figure 1 The filter system shown in Figure 1 has a single filter unit, which has a filter assembly and a forward pressure feed assembly. The filter assembly has, from the inside out, a center tube I, a support tube II, and flexible filter media. The center tube I has no holes in its wall. The support tube II has holes evenly distributed in its wall. The ratio of the diameter of the center tube I to the diameter of the support tube II is 1:3. The distance between the end of the center tube I and the end of the support tube II is 0.3 m. The support tube II has a hole rate of 60% in its wall. The forward pressure feed assembly has, from the inside out, a center tube II, a support tube II, and flexible filter media. The center tube II has no holes in its wall. The upper part of the support tube II has no holes in its wall, and the lower part of the support tube II has holes evenly distributed in its wall. The height of the lower part of the support tube II with holes is half the total height of the support tube II. The other dimensions of the forward pressure feed assembly are the same as those of the filter assembly. The flexible filter media used in the filter assembly and the forward pressure feed assembly has a desolidification layer and a base cloth layer. The specific property parameters are shown in Table 2.

[0062] Table 2

[0063]

[0064] The filter test was carried out using oil slurry A:

[0065] The filter mode was as follows: the flow rate of the feed was 1 kg / h, the filter temperature was 140°C, and the differential pressure setting for the forward pressure feed mode of the filter was 0.30 MPa. At the beginning of the filter mode, the liquid hydrocarbon inlet of the filter was opened to fill the filter 1. The volume of the liquid hydrocarbon above the first tuning fork liquid level meter switch 9 (the third tuning fork liquid level meter 15) was 1.5 L. The volume of the liquid hydrocarbon between the first tuning fork liquid level meter switch 9 and the second tuning fork liquid level meter switch 10 was 4 L. The volume of the liquid hydrocarbon between the third tuning fork liquid level meter switch 15 and the fourth tuning fork liquid level meter switch 16 was 2 L. The volume of the liquid hydrocarbon below the second tuning fork liquid level meter switch 10 was 1.5 L. In the filter mode, the liquid hydrocarbon inlet line 4 and the filtered oil outlet line 5 connected to the filter 1 were open, and the other lines were closed. After the filter 1 ran for 60 h, the pressure drop reached 0.30 MPa, and the forward pressure feed mode was started.

[0066] Forward pressure mode: close liquid hydrocarbon inlet line 4 and filtered oil outlet line 5, open pressure gas inlet line 8 and forward pressure oil outlet line 14, other inlet and outlet lines of the filter are closed, pressure gas (nitrogen) enters the filter through pressure gas inlet line 8, and the liquid hydrocarbon stored in the filter is discharged through forward pressure oil outlet line 14. During the forward pressure mode, the oil slurry A in the filter discharged by the pressure gas is forward pressure oil.

[0067] Deslagging mode: when the liquid level of the filter drops to the fourth tuning fork liquid level gauge 16, close the pressure gas inlet line 8 and the forward pressure oil outlet line 14. Start the deslagging mode, open the filter residue discharge line 6 of the filter, discharge the remaining liquid in the filter, and after the remaining liquid is discharged, start the purging mode.

[0068] Purging mode: introduce purging nitrogen from the back flushing gas tank 11 and lines 12 and 13. The back flushing gas enters the filter through the filtered oil outlet line and the forward pressure oil line for purging, and the material obtained by purging is discharged through the filter residue discharge line 6.

[0069] After the purging mode is completed, the next round of filtration mode is started. The filter 1 undergoes 7 rounds of filtration mode, forward pressure mode, deslagging mode and purging mode, and the filtration time, filtered oil ash content and filtered oil yield of each round of filtration are listed in Table 3.

[0070] Wherein, in each round of filtration, the filtered oil yield = (feed flow rate * time + forward pressure oil volume * oil slurry A density) / (feed flow rate * time + filter 1 oil slurry A volume * oil slurry density) * 100%.

[0071] Table 3

[0072]

[0073] Example 2

[0074] This example uses Figure 1The filter system shown, a single filter is arranged in the filter unit, a filter assembly and a forward pressure feeding assembly are arranged in the filter, the filter assembly is arranged with a center tube I, a support tube II and flexible filter material from inside to outside, the center tube I is not perforated, the support tube I is uniformly perforated, the diameter ratio of the center tube I to the support tube I is 1:5, the distance between the end bottom of the center tube I and the end bottom of the support tube I is 0.5 m, the perforation rate of the support tube I is 80%, the forward pressure feeding assembly is arranged with a center tube II, a support tube II and flexible filter material from inside to outside, the center tube II is not perforated, the upper tube wall of the support tube II is not perforated, the lower tube wall of the support tube II is uniformly perforated, the height of the lower perforated part of the support tube II of the forward pressure feeding assembly is 1 / 3 of the total height of the support tube II, and the other dimensions of the forward pressure feeding assembly are the same as those of the filter assembly. The flexible filter material used in the filter assembly and the forward pressure feeding assembly is provided with a desolidification layer and a base cloth layer, and the specific property parameters are shown in Table 4.

[0075] Table 4

[0076]

[0077] The filter test is carried out by using oil slurry B:

[0078] The filter mode is that the flow rate of the feed is 1.5 kg / h, the filter temperature is 120 DEG C, the differential pressure of the filter is set to 0.40 MPa in the starting pressure feeding mode of the filter. When the filter mode starts, the liquid hydrocarbon inlet of the filter is opened to fill the filter 1, the liquid hydrocarbon volume above the first tuning fork liquid level meter switch 9 (the third tuning fork liquid level meter 15) is 1.5 L, the liquid hydrocarbon volume between the first tuning fork liquid level meter switch 9 and the second tuning fork liquid level meter switch 10 is 4 L, the liquid hydrocarbon volume between the third tuning fork liquid level meter switch 15 and the fourth tuning fork liquid level meter switch 16 is 2.67 L, and the liquid hydrocarbon volume below the second tuning fork liquid level meter switch 10 is 1.5 L. In the filter mode, the liquid hydrocarbon inlet pipeline 4 and the filtered oil outlet pipeline 5 connected with the filter 1 are open, and the other pipelines are closed, the pressure drop of the filter 1 reaches 0.40 MPa after the filter 1 runs for 70 h, and the forward pressure feeding mode is started.

[0079] The forward pressure feeding mode is that the liquid hydrocarbon inlet pipeline 4 and the filtered oil outlet pipeline 5 are closed, the pressure feeding gas inlet pipeline 8 and the forward pressure feeding oil outlet pipeline 14 of the filter are open, and the other inlets and outlets of the filter are closed, the pressure feeding gas (nitrogen) enters the filter from the pressure feeding gas inlet pipeline 8, and the liquid hydrocarbon stored in the filter is pressed out from the forward pressure feeding oil outlet. In the forward pressure feeding mode, the oil slurry B in the filter is the forward pressure feeding oil which is pressed out by the pressure feeding gas.

[0080] Deslagging mode: when the filter liquid level drops to the fourth tuning fork liquid level gauge 16 shows the closing, the pressure gas inlet line 8 and the forward pressure oil outlet line 14 are closed. The deslagging mode is started, the filter's filter residue discharge line 6 is open, the remaining liquid in the filter is discharged, and after the remaining liquid is emptied, the purging mode is started.

[0081] Purging mode: the purging nitrogen is introduced from the back flushing gas tank 11 and the line 12 and the line 13. The back flushing gas enters the filter from the filter oil outlet line and the forward pressure oil line, and the material obtained by purging is discharged from the filter residue discharge line 6.

[0082] After the purging mode is completed, the next round of filtration mode is started. The filter 1 is subjected to 8 rounds of filtration mode, forward pressure mode, deslagging mode and purging mode, and the filtration time, filter oil ash content and filter oil yield of each round of filtration are listed in Table 5.

[0083] Among them, in each round of filtration, the filter oil yield = (feed flow rate * time + forward pressure oil volume * oil slurry B density) / (feed flow rate * time + filter 1 oil slurry B volume * oil slurry density) * 100%.

[0084] Table 5

[0085]

[0086]

[0087] Comparative Example 1

[0088] The same filter system as in Example 1 is used, and the filter test is carried out using oil slurry A. The filtration mode is exactly the same as that of Example 1, and the difference is that there is no forward pressure mode, and the filtration mode is directly switched to deslagging mode and purging mode.

[0089] Filtration mode: feed flow rate 1 kg / h, filtration temperature 140℃, differential pressure setting for starting deslagging mode of filter 0.30MPa. At the beginning of the filtration mode, the liquid hydrocarbon inlet of the filter is opened to fill the filter 1, the liquid hydrocarbon volume above the first tuning fork liquid level gauge switch 9 (third tuning fork liquid level gauge 15) in the filter is 1.5L, the liquid hydrocarbon volume between the first tuning fork liquid level gauge switch 9 and the second tuning fork liquid level gauge switch 10 is 4L, and the liquid hydrocarbon volume below the second tuning fork liquid level gauge switch 10 is 1.5L. In the filtration mode, the liquid hydrocarbon inlet line 4 and the filter oil outlet line 5 connected to the filter 1 are open, and the rest of the pipelines are closed. After the filter 1 runs for 60.1h, the pressure drop reaches 0.30MPa, and the deslagging mode is started.

[0090] Desludging mode: close the liquid hydrocarbon inlet line 4 and the filtered oil outlet line 5, open the filter's sludge discharge line 6, discharge the remaining liquid in the filter, after the remaining liquid is discharged, open the purge mode.

[0091] Purge mode: introduce purge nitrogen from the counter-purge gas tank 11 and line 12. The counter-purge gas enters the filter from the filtered oil outlet line for purging, and the material obtained by purging is discharged from the sludge discharge line 6.

[0092] After the purge mode is completed, the next round of filtration mode is started. The filter 1 is subjected to 7 rounds of filtration mode, desludging mode and purge mode, and the filtration time, filtered oil ash content and filtered oil yield of each round of filtration are listed in Table 6.

[0093] Among them, in each round of filtration, the filtered oil yield = (feed flow rate * time) / (feed flow rate * time + oil slurry A volume in filter 1 during filtration mode * oil slurry density) * 100%.

[0094] Table 6

[0095]

[0096] Comparative Example 2

[0097] The same filtration system as in Example 2 is used, and oil slurry B is used for filtration test, and the filtration mode is exactly the same as that of Example 2, the difference is that there is no forward pressure mode, and the filtration mode is directly switched to desludging mode and purge mode.

[0098] Filtration mode: feed flow rate 1.5 kg / h, filtration temperature 120℃, pressure difference set for filter to start desludging mode 0.40 MPa. At the beginning of the filtration mode, the liquid hydrocarbon inlet of the filter is opened to fill the filter 1, the liquid hydrocarbon volume above the first tuning fork liquid level meter switch 9 (the third tuning fork liquid level meter 15) is 1.5 L, the liquid hydrocarbon volume between the first tuning fork liquid level meter switch 9 and the second tuning fork liquid level meter switch 10 is 4 L, and the liquid hydrocarbon volume below the second tuning fork liquid level meter switch 10 is 1.5 L. In the filtration mode, the liquid hydrocarbon inlet line 4 and the filtered oil outlet line 5 connected to the filter 1 are open, and the rest of the pipelines are closed, and after the filter 1 runs for 68.8 h, the pressure drop reaches 0.40 MPa, and the desludging mode is started.

[0099] Desludging mode: close the liquid hydrocarbon inlet line 4 and the filtered oil outlet line 5, open the filter's sludge discharge line 6, discharge the remaining liquid in the filter, after the remaining liquid is discharged, open the purge mode.

[0100] Purging mode: Purging nitrogen is introduced from the backflushing gas tank 11 and pipeline 12 for backflushing. The backflushing gas enters the filter from the filtered oil outlet pipeline for purging, and the purged material is discharged from the filter residue discharge pipeline 6.

[0101] After the purging mode ends, the next filtration mode is started. Filter 1 goes through 8 filtration modes, slag discharge mode and purging mode. The filtration time, ash content of the filtered oil and oil yield of each filtration mode are listed in Table 7.

[0102] In each round of filtration, the oil yield after filtration is calculated as follows: (feed flow rate * time) / (feed flow rate * time + volume of slurry B in filter 1 during filtration mode * slurry density) * 100%.

[0103] Table 7

[0104]

[0105] Example 3

[0106] use Figure 2 The oil slurry filtration system shown includes filters 1 and 4 in its filtration unit. Each filter contains a filter assembly and a positive pressing assembly of the same size, with specific dimensions identical to those of the filter assembly and positive pressing assembly in Example 1. The flexible filter material in this embodiment has a deconsolidation layer and a base fabric layer, and its specific properties are shown in Table 8.

[0107] Table 8

[0108]

[0109]

[0110] Filtration tests were conducted using coal tar. Two filters, Filter 1 and Filter 4, were operated in parallel. Filter 1 was put into operation first. After Filter 1 ran in filtration mode for 24 hours, Filter 4 was put into operation. At this time, both Filter 1 and Filter 4 were in filtration mode. Each filter's filtration process consisted of the following steps in sequence: filtration mode, positive pressure mode, slag discharge mode, and purging mode. The filtration mode time for each filter was set to 45 hours.

[0111] Filter 1 filtration mode: feed flow rate 2.0 kg / h, filtration temperature 150°C. The time for filter 1 to start forward pressure mode was set to 45 h. At the beginning of the filtration mode, the liquid hydrocarbon inlet of the filter was opened, and the filter 1 was filled with coal tar. The volume of coal tar above the first tuning fork level gauge switch 21 (third tuning fork level gauge switch 23) was 1.5 L, the volume of coal tar between the first tuning fork level gauge switch 21 and the second tuning fork level gauge switch 22 was 4 L, the volume of coal tar between the third tuning fork level gauge switch 23 and the fourth tuning fork level gauge switch 24 was 2.0 L, and the volume of coal tar below the second tuning fork level gauge switch 22 was 1.5 L. The coal tar was filtered through the filter 1 via the liquid hydrocarbon inlet line 7, and the filtered oil was discharged via the filtered oil outlet line 9. After 45 h of operation, the filter 1 started forward pressure mode.

[0112] Filter 1 forward pressure mode: the liquid hydrocarbon inlet line 7 and the filtered oil outlet line 9 were closed, the filter 1 pressure gas inlet line 19 and the filter 1 forward pressure oil outlet line 11 were open, and the other inlets and outlets of the filter 1 were closed. The pressure gas (nitrogen) entered the filter 1 via the pressure gas inlet line 19, and the coal tar stored in the filter 1 was discharged via the forward pressure oil outlet line 11. During the forward pressure mode, the coal tar in the filter 1 was the forward pressure oil.

[0113] Filter 1 slag discharge mode: when the liquid level of the filter 1 was lowered to the point at which the fourth tuning fork level gauge 24 was closed, the pressure gas inlet line 19 and the forward pressure oil outlet line 11 were closed, and the slag discharge mode was started. The filter 1 slag discharge line 29 was open, and the remaining liquid in the filter 1 was discharged.

[0114] Filter 1 purge mode: after the remaining liquid was discharged, the filter 1 was purged with nitrogen from the backflush gas tank 13 and the lines 15 and 16. The backflush gas entered the filter 1 via the filtered oil outlet line and the forward pressure oil outlet line, and the material obtained by the purge was discharged via the slag discharge line 29.

[0115] After the purge mode was completed, the next filtration mode was started. The filter 1 was subjected to two filtration modes, forward pressure mode, slag discharge mode, and purge mode. The filtration time, filtered oil ash content, and filtered oil yield for each filtration are listed in Table 9.

[0116] In each filtration, the filtered oil yield = (feed flow rate * time + forward pressure oil volume * coal tar density) / (feed flow rate * time + coal tar volume in the filter 1 during the filtration mode * coal tar density) * 100%.

[0117] Filter 4 filtration mode: feed flow rate 2.0 kg / h, filtration temperature 150°C. The time for filter 4 to start forward pressure mode was set at 45 h. At the start of the filtration mode, the liquid hydrocarbon inlet of filter 4 was opened, and filter 4 was filled with coal tar, with the volume of coal tar above the first tuning fork level switch 25 (third tuning fork level switch 27) being 1.5 L, the volume of coal tar between the first tuning fork level switch 25 and the second tuning fork level switch 26 being 4 L, the volume of coal tar between the third tuning fork level switch 27 and the fourth tuning fork level switch 28 being 2.0 L, and the volume of coal tar below the second tuning fork level switch 26 being 1.5 L. The coal tar was filtered through filter 4 via the liquid hydrocarbon inlet line 8, and the filtered oil was removed via the filtered oil outlet line 10. After 45 h of operation, filter 4 started forward pressure mode.

[0118] Filter 4 forward pressure mode: the liquid hydrocarbon inlet line 8 and the filtered oil outlet line 10 were closed, and the pressure gas inlet line 20 of filter 4 and the forward pressure oil outlet line 12 of filter 4 were open, while the other inlets and outlets of filter 4 were closed. The pressure gas (nitrogen) was introduced into filter 4 via the pressure gas inlet line 20, and the coal tar stored in filter 4 was forced out of filter 4 via the forward pressure oil outlet line 12. During the forward pressure mode, the coal tar forced out of filter 4 via the pressure gas was forward pressure oil.

[0119] Filter 4 deslagging mode: when the liquid level of filter 4 dropped to the point at which the fourth tuning fork level switch 28 was closed, the pressure gas inlet line 20 and the forward pressure oil outlet line 12 were closed, and the deslagging mode was started. The filtered residue outlet line 30 of filter 4 was open, and the remaining liquid in filter 4 was removed.

[0120] Filter 4 purging mode: after the remaining liquid was removed, the filter 4 was purged with nitrogen introduced from the backflush gas tank 13 and lines 17 and 18. The backflush gas was introduced into filter 4 via the filtered oil outlet line and the forward pressure oil outlet line, and the material purged was removed via the filtered residue outlet line 30.

[0121] After the purging mode was completed, the next filtration mode was started. Filter 4 was operated for two cycles of filtration mode, forward pressure mode, deslagging mode, and purging mode. The filtration time, filtered oil ash content, and filtered oil yield for each cycle of filtration are shown in Table 9.

[0122] wherein, for each cycle of filtration, the filtered oil yield = (feed flow rate * time + forward pressure oil volume * coal tar density) / (feed flow rate * time + coal tar volume in filter 1 during filtration mode * coal tar density) * 100%.

[0123] Table 9

[0124]

[0125] From the above results of the present application, it can be seen that the liquid hydrocarbon filtration system and filtration method provided by the present application can significantly improve the yield of the filtered product.

Claims

1. A liquid hydrocarbon filtration system, comprising a filtration unit and a regeneration unit, wherein the filtration unit is provided with a filter, the filter having at least one filter element and at least one positive pressurizing element, a liquid hydrocarbon inlet is provided at the bottom of the filter, a filtered oil outlet and a positive pressurizing oil outlet are provided at the top of the filter, a filter residue outlet is provided at the bottom of the filter, a pressurizing gas inlet is provided at the top of the filter, and a liquid hydrocarbon inlet pipeline, a filtered oil outlet pipeline, a positive pressurizing oil outlet pipeline, a filter residue discharge pipeline, and a pressurizing gas inlet pipeline are respectively connected to each filter. The filter assembly consists of, from the inside out, a central tube I, a support tube I, and a flexible filter material. The central tube I has no holes in its wall, while the support tube I has evenly spaced holes in its wall. A first tuning fork level switch and a second tuning fork level switch are respectively installed at the upper and lower ends of the support tube I. The positive pressure assembly consists of, from the inside out, a central tube II, a support tube II, and a flexible filter material. The central tube II has no holes in its wall, while the upper part of the support tube II has no holes, and the lower part of its wall has evenly spaced holes. A third tuning fork level switch and a fourth tuning fork level switch are respectively installed at the upper and lower ends of the non-perforated portion of the support tube II. The regeneration unit is equipped with a backflush gas tank and a pressurizing gas tank. The outlet pipeline of the backflush gas tank is connected to the outlet pipeline of the filtered oil, and the outlet pipeline of the backflush gas tank is connected to the outlet pipeline of the forward pressurizing oil. The outlet pipeline of the pressurizing gas tank is connected to the pressurizing gas inlet at the top of the filter.

2. The system according to claim 1, characterized in that, The diameter ratio of the central tube I to the support tube I ranges from 1:2 to 1:6, the distance between the bottom end of the central tube I and the bottom end of the support tube I is 0.2m to 0.8m, and the opening rate on the wall of the support tube I is 55% to 85%.

3. The system according to claim 1, characterized in that, The diameter ratio of the central tube II to the support tube II is in the range of 1:2 to 1:

6. The distance between the bottom end of the central tube II and the bottom end of the support tube II is 0.2m to 0.8m. The opening rate of the opening portion on the wall of the support tube II is 55% to 85%. The height of the opening portion on the wall of the support tube II is 1 / 2 to 1 / 3 of the total height of the support tube II.

4. The system according to claim 1, characterized in that, The first tuning fork level gauge switch and the third tuning fork level gauge switch are in the same horizontal position.

5. The system according to any one of claims 1-3, characterized in that, The flexible filter material is selected from one or more of polyethylene, nylon, polyphenylene sulfide, polyimide, polytetrafluoroethylene, aramid, polyurethane, and glass fiber.

6. The system according to any one of claims 1-3, characterized in that, The flexible filter material is a flexible filter material composed of any two or more of the following: polyethylene, nylon, polyphenylene sulfide, polyimide, polytetrafluoroethylene, aramid, polyurethane, and glass fiber.

7. The system according to claim 1, characterized in that, The filtration precision of flexible filter media is 0.1~15 microns, and the basis weight of flexible filter media is 300~1000g / m³. 2 The longitudinal fracture strength is 850N / 5cm~9000N / 5cm, the latitudinal fracture strength is 1000N / 5cm~11000N / 5cm, and the thickness is 0.5~3.4mm.

8. The system according to claim 1, characterized in that, The flexible filter material includes a debonding layer and a base fabric layer. The porosity of the debonding layer is 25% to 98%, and the porosity of the base fabric layer is 30% to 40%. The base fabric layer is made of polytetrafluoroethylene and / or polyphenylene sulfide, and the debonding layer is made of polytetrafluoroethylene.

9. The system according to claim 1, characterized in that, The backflush gas in the backflush gas tank is nitrogen and / or fuel gas; the pressurizing gas in the pressurizing gas tank is nitrogen and / or fuel gas.

10. A method for filtering liquid hydrocarbons using any one of the filtration systems of claims 1-9, comprising: Filtration mode: The liquid hydrocarbon inlet and the filtered oil outlet of the filter are open, while the other inlets and outlets of the filter are closed. After the liquid hydrocarbon enters the filter through the liquid hydrocarbon inlet pipeline, the liquid hydrocarbon flows from the bottom to the top of the central pipe I of the filter assembly. The filtered oil is discharged from the top of the central pipe I and is then drawn out from the filtered oil outlet of the filter. Forward pressing mode: The pressurizing gas inlet and the forward pressurizing oil outlet of the filter are open, while the other inlets and outlets of the filter are closed. Pressurizing gas enters the forward pressing component of the filter from the pressurizing gas inlet, forcing the liquid hydrocarbon stored in the filter out from the forward pressurizing oil outlet of the filter and mixing it with the filtered oil. Sludge discharge mode: The filter sludge outlet is open, while the other inlets and outlets of the filter are closed, so that the residual liquid hydrocarbons in the filter are discharged. Purging mode: The filter cake outlet of the filter is in the open state. Backflush gas enters the filter from the filtered oil outlet pipeline and the forward pressing oil outlet pipeline for purging. The backflush gas flows from the top of the central tube I of the filter assembly down to the bottom and is then discharged, purging the inner surface of its flexible filter media. The backflush gas flows from the top of the central tube II of the forward pressing assembly down to the bottom and is then discharged, purging the inner surface of its flexible filter media.

11. The method according to claim 10, characterized in that, In filtration mode, the filtration temperature in the filter is 30~250℃; The pressure differential during filter use is 0.01~0.5MPa.

12. The method according to claim 10, characterized in that, In filtration mode, the filtration temperature in the filter is 60~180℃.

13. The method according to claim 10, characterized in that, In filtration mode, the filter is set to a filtration time of 24h~96h.

14. The method according to claim 10, characterized in that, In filtration mode, when the differential pressure of the filter reaches or exceeds the differential pressure set value, or when the set time is reached, the filter is switched to positive pressure mode operation. The filtration mode ends and the forward pressing mode begins. At this time, the oil slurry level in the filter is higher than the first tuning fork level gauge switch. In the forward pressing mode, when the oil slurry level in the filter drops to the fourth tuning fork level gauge switch, the forward pressing mode stops and switches to the slag discharge mode.

15. The method according to claim 10, characterized in that, When a filter is installed in the filtration unit, the operation is carried out in an alternating manner, using filtration mode, positive pressing mode, slag discharge mode, purging mode, and the next round of filtration mode, positive pressing mode, slag discharge mode, and purging mode.

16. The method according to claim 10, characterized in that, When a filtration unit is equipped with multiple filters, when the differential pressure of a certain online filter reaches or exceeds the differential pressure set value or reaches the set time, the filter is disconnected from the filtration system and regenerated in positive pressing mode, slag discharge mode and purging mode.

17. The system according to claim 10, characterized in that, The liquid hydrocarbon is catalytic cracking slurry and / or coal tar.

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