A continuous coking production system and process for hydrocracked unconverted oil

Abstract

The application belongs to the technical field of petroleum chemical industry and relates to a continuous coking production system and process method of hydrogenation unconverted oil. The production system comprises a membrane filter, a raw material tank, a homogenizer, a tubular furnace, a coking machine, an oil cooler and a stock bin. The application realizes the continuous production of high-quality petroleum coke by the synergistic process method of membrane filtration-modification-homogeneous emulsification-tubular furnace coking machine coupling combined with graphite addition and hydraulic conveying technology without noble metal catalyst. The sulfur content, ash content and volatile content of the petroleum coke prepared by the process method of the application all meet the industry standards and can meet the demand of electrolytic aluminum for pre-cultured low-emission anode coke, and the cost is low.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of petrochemical industry, and relates to a continuous coking production system and process method of hydrogenated unconverted oil. BACKGROUND

[0002] Petroleum coke is an important byproduct in the refining process of crude oil, and is widely used in steelmaking, aluminum smelting, chemical industry and other fields. Petroleum coke is a solid carbonaceous residue formed by thermal cracking and condensation reactions during the coking process of crude oil or heavy residual oil at high temperature (usually 450-550℃), and its main component is carbon (80-95%), and it also contains a small amount of sulfur, nitrogen, oxygen, heavy metals (such as vanadium and nickel) and ash. With the increasingly stringent environmental regulations, the use of high-sulfur petroleum coke (sulfur content > 3%) is strictly limited, and the market demand for low-sulfur petroleum coke has increased significantly. High-quality petroleum coke is in high demand for electrolytic aluminum, but it is expensive, which limits the use of petroleum coke.

[0003] The traditional heavy oil coking process mainly uses oil slurry as raw material, which is pretreated and then directly heated in a tubular furnace, followed by cracking and condensation reactions in 2-4 coking towers, and finally petroleum coke is produced. Although this process has been industrialized, it still has the following problems: the composition of heavy oil is complex, and asphaltene, resin and solid impurities can easily cause coking in the tubular furnace, reduce heat transfer efficiency, and need frequent shutdown for decoking, affecting continuous production; low product quality: the sulfur content of direct coking petroleum coke is high, the structure is loose, and the specific surface area is small, which is difficult to meet the demand of high value-added applications (such as electrode grade coke); the traditional process is not sufficient for heavy oil modification, the selectivity of cracking reaction is poor, the yield of light oil is low, and harmful gases (such as SO x , NO x ) are easily produced in the high-temperature coking process.

[0004] In order to improve the quality of petroleum coke, Chinese patent CN113563921A discloses a method and system for producing low-sulfur petroleum coke, mainly by combining residual oil hydrogenation, catalytic cracking and delayed coking process to produce low-sulfur petroleum coke. The following disadvantages exist: complex system, involving multiple unit combination of residual oil hydrogenation, catalytic cracking and delayed coking, high operation difficulty; high requirement for raw materials, sulfur content > 3.0%; high energy consumption, large amount of hydrogen gas (1.1%-1.5% of feedstock) and high pressure equipment are required for hydrogenation desulfurization. The overall process method has poor economic efficiency and operation continuity, and limited raw material adaptability. Chinese patent CN115197748A discloses a method and system for producing low-carbon olefins and low-sulfur coke. The system requires multiple process method coupling (hydrogenation + coking + cracking), which is difficult to operate and maintain. It is only suitable for high-sulfur residual oil, the cost of hydrogenation pretreatment is high and it is easily affected by raw material fluctuations, it relies on high-pressure hydrogenation and a large amount of hydrogen gas, the equipment investment is huge, and a noble metal catalyst is required. The olefin yield needs to be sacrificed for the coking scale, and the economic balance is difficult, there are multi-link pollutant emissions, additional treatment facilities are required, and the continuity needs to be improved.

[0005] Therefore, it is urgent to develop a continuous coking production system for high-quality petroleum coke with simplified process, strong raw material adaptability and low cost and low energy consumption, to break through the limitations of the prior art. SUMMARY

[0006] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a continuous coking production system and process method for hydrogenated unconverted oil, which realizes the continuous production of high-quality petroleum coke through the synergistic process method of membrane filtration-modification-homogeneous emulsification-tube furnace coking machine coupling, combined with graphite addition and hydraulic conveying technology, without noble metal catalyst.

[0007] The technical scheme adopted by the present application to solve the technical problems is:

[0008] The present application provides a continuous coking production system for hydrogenated unconverted oil, which comprises a membrane filter, a raw material tank, a homogenizer, a tube furnace, a coking machine, an oil cooler and a bin. The membrane filter has a hydrogenated unconverted oil inlet, a filtered oil slurry outlet and a filtered material outlet. The filtered oil slurry outlet pipeline is connected to the inlet of the raw material tank in turn through a raw material preheater and a modifier. The homogenizer has a water inlet, a graphite addition port, a raw material inlet and a polyacrylamide addition port. The outlet of the raw material tank is connected to the raw material inlet of the homogenizer through a pipeline. The outlet pipeline of the homogenizer is connected to the inlet of the tube furnace. The outlet of the tube furnace is connected to the inlet of the coking machine through a pipeline. The outlet of the coking machine is connected to the inlet of the oil cooler through a pipeline. The outlet of the oil cooler is connected to the bin through a pipeline.

[0009] Further, the water inlet pipeline of the homogenizer is connected to the outlet of the water tank in turn through a first flow meter and a water pump.

[0010] Further, a raw material pump and a second flow meter are sequentially installed on an outlet pipeline of the raw material tank.

[0011] Further, the membrane filter is a sintered inorganic membrane filter. The inorganic membrane has a pore size ranging from 80 nm to 110 nm.

[0012] Further, the coking machine is a plow coking machine, which is internally provided with a rotating plow assembly, and the number of plows is 4-36.

[0013] Further, the oil cooler is a rake type vacuum external tube cooler, and the refrigerant is heat conducting oil.

[0014] Another aspect of the present application provides a process for a continuous coking production system, comprising the following steps:

[0015] (1) The hydrogenation unconverted oil passes through the membrane filter to obtain the filtered crude slurry and the filtered oil slurry. The filtered oil slurry is heated to 340-360℃ in the raw material preheater, enters the modifier, and after modification, enters the raw material tank. The modified raw material is pumped into the homogenizer by the raw material pump. Graphite and polyacrylamide emulsifier are added during the homogenization process. The graphite accounts for 0.03-0.05% of the mass of the oil slurry, and the polyacrylamide emulsifier accounts for 0.1-0.5% of the mass of the oil slurry. At the same time, 0.5-1% of the mass of the oil slurry is pumped into water (the function of water is to increase the flow rate and prevent coking of the oil slurry in the pipe furnace, and further remove nitrogen oxides). The homogenization temperature is 400-450℃, the homogenization time is 3-5 hours, the homogenization pressure is 0.1-0.6 MPa, and the homogenizer rotation speed is 3000 rpm±50 rpm;

[0016] (2) The homogenized oil slurry enters the pipe furnace and is heated to 450-480℃, and stays for 20-40 seconds, then enters the coking machine, and the coking machine temperature is 470-490℃, and the pressure is 0.1-0.6 MPa;

[0017] (3) After the oil slurry stays in the coking machine for 8-10 hours, it is cooled to 140-160℃ in the oil cooler after coking, and the petroleum coke particles enter the stock bin after cooling, and are finally packaged.

[0018] Further, the hydrogenation unconverted oil has an aromatic hydrocarbon content of 62-70 wt%, and a saturated hydrocarbon content of 8-12 wt%.

[0019] Further, the operating temperature of the membrane filtration is 280-300℃, preferably 290℃. The transmembrane pressure difference of the membrane filtration is 0.4-0.6 MPa. The feed flow rate of the membrane filtration is 2-5 m / s, and the suitable feed can prevent membrane pollution.

[0020] Further, the operating temperature range of the oil cooler is 80-200℃.

[0021] Further, the coking machine is heated by 450-550℃ molten salt.

[0022] The innovation points of the present application are as follows:

[0023] (1) By combining the membrane filter with the modifier, a modular pretreatment unit is formed. The membrane filter efficiently removes impurities such as gum and asphaltene, and the modifier reduces the viscosity of the raw material through mild thermal cracking. The two work together to significantly improve the subsequent coking efficiency. The homogenizer simultaneously adds conductive graphite and polyacrylamide emulsifier. The graphite can increase the condensation nucleus and control the microstructure of the coke, while the emulsifier can prevent asphaltene agglomeration through charge stabilization. Quantitative water injection by water pump not only improves the fluidity of the system (reduces the risk of pipe furnace coking), but also serves as a heat carrier to improve heat transfer efficiency.

[0024] (2) Tube furnace-coking machine coupled reactor: continuous coupling of tube furnace and plow-type coking machine is adopted to realize 8-10 hour constant temperature coking of materials, avoiding the switching energy consumption of traditional coke tower.

[0025] (3) Molten salt heating system: molten salt is used as the heating medium in the coking machine, which is more precise in temperature control than steam heating and reduces energy consumption.

[0026] The advantages and positive effects of the present application are:

[0027] (1) The continuous coking production system of the present application realizes the continuous production of high-quality petroleum coke through the synergistic process method of membrane filtration-modification-homogenization-emulsification-tube furnace coking machine coupling, combined with graphite addition and hydraulic conveying technology, without the need for noble metal catalysts.

[0028] (2) The process method of the present application produces petroleum coke with low sulfur content (S≤2wt%), which can meet the demand of electrolytic aluminum for low-emission anode coke, and has low cost. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The process flow chart of the continuous coking production system of the present application. DETAILED DESCRIPTION

[0030] As a specific embodiment of the present application, the present application provides a continuous coking production system of hydrocracking unconverted oil, comprising a membrane filter, a raw material tank, a homogenizer, a tubular furnace, a coking machine, an oil cooler and a bunker, the membrane filter has a hydrocracking unconverted oil inlet, a filtered oil slurry outlet and a filtered material outlet, the filtered oil slurry outlet pipeline is connected to the inlet of the raw material tank in turn through a raw material preheater and a modifier, the homogenizer has a water inlet, a graphite adding port, a raw material inlet and a polyacrylamide adding port, the outlet of the raw material tank is connected to the raw material inlet of the homogenizer through a pipeline, the outlet of the homogenizer is connected to the inlet of the tubular furnace through a pipeline, the outlet of the tubular furnace is connected to the inlet of the coking machine through a pipeline, the outlet of the coking machine is connected to the inlet of the oil cooler through a pipeline, and the outlet of the oil cooler is connected to the bunker through a pipeline.

[0031] Specifically, the water inlet pipeline of the homogenizer is connected to the outlet of the water tank in turn through a first flow meter and a water pump.

[0032] Specifically, a raw material pump and a second flow meter are installed in turn on the outlet pipeline of the raw material tank.

[0033] Specifically, the membrane filter is a sintered inorganic membrane filter. The pore size of the inorganic membrane ranges from 80 to 110 nm.

[0034] Specifically, the coking machine is a plow blade coking machine, which is provided with a rotating plow blade assembly inside, and the number of plow blades is 4-36.

[0035] Specifically, the oil cooler is a rake type vacuum external tube cooler, and the refrigerant is heat conducting oil.

[0036] As another specific embodiment of the present application, the present application provides a process method for a continuous coking production system, the steps are as follows:

[0037] (1) After the hydrocracking unconverted oil passes through the membrane filter, a crude slurry and a filtered oil slurry are obtained, the filtered oil slurry is heated to 340-360℃ in the raw material preheater, enters the modifier, and after modification, enters the raw material tank, the modified raw material is pumped into the homogenizer by the raw material pump, graphite and polyacrylamide emulsifier are added in the homogenizing process, the graphite accounts for 0.03-0.05% of the mass of the oil slurry, the polyacrylamide emulsifier accounts for 0.1-0.5% of the mass of the oil slurry, (the function of graphite: increase the condensation nucleus, the function of polyacrylamide emulsifier: emulsify the oil slurry and water) at the same time, 0.5-1% of the mass of the oil slurry of water is pumped in (the function of water is to increase the flow rate and prevent coking of the oil slurry in the tubular furnace), 400-450℃ homogenization for 3-5 hours, the homogenization pressure is 0.1-0.6MPa, and the rotation speed of the homogenizer is 3000rpm±50rpm;

[0038] (2) The homogenized oil slurry enters a tubular furnace and is heated to 450-480℃ and stays for 20-40 seconds, then enters a coking machine, the temperature of which is 470-490℃ and the pressure is 0.2-0.6 MPa;

[0039] (3) The oil slurry stays in the coking machine for 8-10 hours, then enters an oil cooler for cooling to 140-160℃, and the cooled petroleum coke particles enter a storage bin and are finally packaged.

[0040] Specifically, the hydrocracking unconverted oil contains 62-70 wt% of aromatic hydrocarbons and 8-12 wt% of saturated hydrocarbons.

[0041] Specifically, the operating temperature of the membrane filtration is 280-300℃, preferably 290℃. The transmembrane pressure difference of the membrane filtration is 0.4-0.6 MPa. The feed flow rate of the membrane filtration is 2-5 m / s, which is suitable for preventing membrane fouling.

[0042] Specifically, the operating temperature range of the oil cooler is 80-200℃.

[0043] Specifically, the coking machine is heated by 450-550℃ molten salt.

[0044] The application will be further described in detail below by specific examples, which are only descriptive and not limiting, and cannot limit the protection scope of the application.

[0045] Example 1

[0046] A continuous coking production system of hydrocracking unconverted oil includes a membrane filter, a raw material tank, a homogenizer, a tubular furnace, a coking machine, an oil cooler and a storage bin. The membrane filter is a sintered inorganic membrane filter, and the pore size of the membrane is 100 nm.

[0047] The membrane filter can efficiently remove ≥0.1 μm of gum / asphaltene particles in the hydrocracking unconverted oil to provide high-quality raw materials for subsequent coking. The membrane filter has a hydrocracking unconverted oil inlet, a filtered oil slurry outlet and a filtered material outlet. The filtered oil slurry outlet is connected to the inlet of the raw material tank through a pipeline in sequence through a raw material preheater and a reformer. The raw material tank serves as a buffer container to store the filtered oil slurry, ensuring continuous feeding and stable system pressure balance. The outlet of the raw material tank is connected to the raw material inlet of the homogenizer through a pipeline, and a raw material pump and a second flow meter are installed in sequence on the outlet pipeline of the raw material tank.

[0048] The homogenizer realizes the homogenization of the oil slurry components and regulates the conductivity of the coke through high-shear dispersion. The homogenizer has a water inlet, a graphite adding port, a raw material inlet and a polyacrylamide adding port. The water inlet pipeline of the homogenizer is connected to the outlet of the water tank in sequence through a first flow meter and a water pump.

[0049] The outlet of the homogenizer is connected to the inlet of the tubular furnace through a pipeline, the tubular furnace can quickly heat the homogenized oil slurry to provide the reaction activation energy required for coking. The outlet pipeline of the tubular furnace enters the inlet of the coking machine, and the outlet of the coking machine is connected to the inlet of the oil cooler through a pipeline, and the outlet of the oil cooler is connected to the bin through a pipeline. The coking machine is a plow blade type coking machine, which is provided with a rotating plow blade assembly inside, the number of plow blades is 12, and the oil slurry is continuously coked by stirring through the plow blades to generate coke with compact structure. The oil cooler is a rake type vacuum external tube cooler, the refrigerant is heat conducting oil, and the coke is gradient cooled by using the heat conducting oil to avoid thermal stress cracking and recover waste heat.

[0050] The heat recovered by the oil cooler can be used for preheating of the raw material preheater to form a heat recycling.

[0051] Example 2

[0052] Table 1 composition and content of hydrogenation unconverted oil

[0053]

[0054] A process method for the continuous coking production system of example 1, the steps are as follows:

[0055] (1) The hydrogenation unconverted oil (composition as shown in table 1) is filtered through a sintered inorganic membrane filter to obtain filtered oil slurry and coarse slurry (the coarse slurry is treated by drying to recover valuable metals), the filtration temperature is 290℃, and the transmembrane pressure difference is 0.6MPa. The filtered oil slurry after membrane filtration enters the raw material preheater at a feed flow rate of 5m / s, is heated to 350℃, enters the modifier, is modified, enters the raw material tank, and the modified raw material is pumped into the homogenizer by the raw material pump, graphite and polyacrylamide emulsifier are added in the homogenizing process, the graphite accounts for 0.05% of the mass of the oil slurry, the polyacrylamide emulsifier accounts for 0.5% of the mass of the oil slurry, and at the same time, 0.5% of the mass of the oil slurry is pumped into water, 450℃ homogenization for 4 hours, the homogenization pressure is 0.6MPa, and the homogenizer rotates at 3000rpm;

[0056] (2) The homogenized oil slurry enters the tubular furnace and is heated to 460℃, stays for 30 seconds, enters the coking machine, and the temperature of the coking machine is 480℃ and the pressure is 0.5MPa;

[0057] (3) After the oil slurry stays in the coking machine for 9 hours, the coking machine is heated with 500℃ molten salt, and after coking, it enters the oil cooler for cooling to 150℃, and after cooling, the petroleum coke particles are obtained, enter the bin, and finally are packaged.

[0058] Example 3

[0059] A process method for the continuous coking production system of example 1, the steps are as follows:

[0060] (1) The filter oil slurry and crude slurry obtained by filtering the hydrogenation unconverted oil (composition as shown in Table 1) through a sintered inorganic membrane filter, the filtration temperature is 290℃, and the transmembrane pressure difference is 0.4MPa. The filter oil slurry after membrane filtration enters the raw material preheater at a feed flow rate of 3m / s, is heated to 350℃, enters the modifier, after modification, enters the raw material tank, and the modified raw material is pumped into the homogenizer by the raw material pump, graphite and polyacrylamide emulsifier are added in the homogenization process, the graphite accounts for 0.05% of the mass of the oil slurry, the polyacrylamide emulsifier accounts for 0.1-0.5%, and at the same time, 1% of the mass of the oil slurry is pumped into water (the water is used to increase the flow rate and prevent coking of the oil slurry in the tubular furnace), the homogenization temperature is 430℃, the homogenization time is 5 hours, the homogenization pressure is 0.5MPa, and the homogenizer rotation speed is 3000rpm;

[0061] (2) The homogenized oil slurry enters the tubular furnace and is heated to 450℃, and stays for 40 seconds, then enters the coking machine, the coking machine temperature is 470℃, and the pressure is 0.6MPa;

[0062] (3) After the oil slurry stays in the coking machine for 8 hours, the coking machine is heated with 500℃ molten salt, and after coking, it enters the oil cooler for cooling to 140℃, and then the petroleum coke particles are obtained, which enter the stock bin and are finally packaged.

[0063] Comparative Example 1

[0064] The difference from Example 2 is only that the graphite is replaced by micron-sized similar green coke.

[0065] Comparative Example 2

[0066] The difference from Example 2 is only that no polyacrylamide emulsifier is added.

[0067] Comparative Example 3

[0068] The difference from Example 2 is only that the homogenization temperature is 460℃.

[0069] Comparative Example 4

[0070] The difference from Example 2 is only that the homogenization temperature is 390℃.

[0071] The petroleum coke prepared in Examples 2-3 and Comparative Examples 1-4 is detected for composition, and the quality index is in accordance with the industry standard YBYJJ-1, the sulfur content is ≤2wt%, the volatile content is ≤10wt%, the ash content is ≤0.3wt%, the fixed carbon content is ≥85wt%, and the pellet coke content is 0.

[0072] Table 2 Component content and performance of petroleum coke product

[0073]

[0074] Comparative Example 1: Graphite is replaced by green coke, the sulfur content is significantly increased, which exceeds the industry standard (≤2wt%), the ash content and volatile matter are worse than the embodiment, and the shot coke appears 0.8wt%, which shows that the addition of conductive graphite can effectively reduce the sulfur content, and the polycondensation nucleus effect of graphite can optimize the structure of coke and reduce impurities. Green coke cannot regulate micro-homogeneity like graphite.

[0075] Comparative Example 2: The emulsifier is missing, the sulfur content is further increased, the ash content and volatile matter are increased, and the shot coke appears 0.6wt%, which proves that the charge stabilization effect of polyacrylamide can inhibit the aggregation of asphaltene (reduce sulfide wrapping), and the lack of emulsifier leads to uneven dispersion of impurities, and the increase of side reactions in the pyrolysis process.

[0076] Comparative Example 3: The homogenization temperature is 460℃, the sulfur content (2.82wt%) and shot coke (1wt%) are the worst, because the temperature is too high, which leads to excessive cracking and produces unstable intermediate products.

[0077] Comparative Example 4: The homogenization temperature is 390℃, the volatile matter (3.9wt%) is lower but the sulfur content is still high (2.93wt%), which shows that when the temperature is insufficient, the modification is not sufficient, and the desulfurization efficiency of gum is decreased.

[0078] And the fixed carbon of all comparative examples is lower than the embodiment, which highlights the advantage of the embodiment process in improving carbon purity.

[0079] The above only describes the preferred embodiments of the present application, and it should be pointed out that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the protection scope of the present application.

Claims

1. A continuous coking production system of hydrocracked unconverted oil, characterized by, The application relates to a hydrogenation unconverted oil treatment system, which comprises a membrane filter, a raw material tank, a homogenizer, a tubular furnace, a coking machine, an oil cooler and a bin, the membrane filter is provided with a hydrogenation unconverted oil inlet, a filtered oil slurry outlet and a filtered material outlet, the filtered oil slurry outlet pipeline is sequentially connected to the inlet of the raw material tank through a raw material preheater and a modifier, the homogenizer is provided with a water inlet, a graphite adding port, a raw material inlet and a polyacrylamide adding port, the outlet of the raw material tank is connected to the raw material inlet of the homogenizer through a pipeline, the outlet pipeline of the homogenizer is connected to the inlet of the tubular furnace, the outlet of the tubular furnace is connected to the inlet of the coking machine through a pipeline, the outlet of the coking machine is connected to the inlet of the oil cooler through a pipeline, the outlet of the oil cooler is connected to the bin through a pipeline, and the modifier reduces the viscosity of the raw material through mild thermal cracking; the hydrogenation unconverted oil is filtered through the membrane filter to obtain a filtered material coarse slurry and a filtered oil slurry, the filtered oil slurry is heated to 340-360 DEG C in the raw material preheater, enters the modifier, and then enters the raw material tank after modification; the modified raw material is pumped into the homogenizer through a raw material pump; graphite and polyacrylamide emulsifiers are added in the homogenizing process, the graphite accounts for 0.03-0.05% of the mass of the oil slurry, the polyacrylamide emulsifier accounts for 0.1-0.5% of the mass of the oil slurry, and 0.5-1% of the mass of the oil slurry is pumped into water at the same time; the homogenization is carried out at 400-450 DEG C for 3-5 hours, and the homogenization pressure is 0.1-0.6 MPa.

2. The continuous coking production system of claim 1, wherein, The water inlet pipeline of the homogenizer is sequentially connected to the outlet of a water tank through a first flowmeter and a water pump.

3. The continuous coking production system of claim 1, wherein, A raw material pump and a second flowmeter are sequentially installed on the outlet pipeline of the raw material tank.

4. The continuous coking production system of claim 1, wherein, The membrane filter is a sintered inorganic membrane filter, and the pore size of the inorganic membrane ranges from 80 nm to 110 nm.

5. The continuous coking production system of claim 1, wherein, The coking machine is a plowshare type coking machine.

6. The continuous coking production system of claim 1, wherein, The oil cooler is a rake type vacuum external tube cooler, and the refrigerant is heat-conducting oil.

7. A process for use in a continuous coking production system according to any one of claims 1-6, characterized in that, The steps are as follows: (1) the hydrogenation unconverted oil is filtered through the membrane filter to obtain a filtered material coarse slurry and a filtered oil slurry, the filtered oil slurry is heated to 340-360 DEG C in the raw material preheater, enters the modifier, and then enters the raw material tank after modification; the modified raw material is pumped into the homogenizer through a raw material pump; graphite and polyacrylamide emulsifiers are added in the homogenizing process, the graphite accounts for 0.03-0.05% of the mass of the oil slurry, the polyacrylamide emulsifier accounts for 0.1-0.5% of the mass of the oil slurry, and 0.5-1% of the mass of the oil slurry is pumped into water at the same time; the homogenization is carried out at 400-450 DEG C for 3-5 hours, and the homogenization pressure is 0.1-0.6 MPa; (2) the homogenized oil slurry is heated to 450-480 DEG C in the tubular furnace and stays for 20-40 seconds, enters the coking machine, and the temperature of the coking machine is 470-490 DEG C and the pressure is 0.1-0.6 MPa; (3) the oil slurry stays in the coking machine for 8-10 hours, and then enters the oil cooler for cooling to 140-160 DEG C after coking; after cooling, the petroleum coke particles enter the bin and are finally packaged.

8. The process of claim 7, wherein, The hydrogenation unconverted oil contains 62-70 wt% of aromatic hydrocarbons and 8-12 wt% of saturated hydrocarbons.

9. The process of claim 7, wherein, The operation temperature of the membrane filtration is 280-300 DEG C, the transmembrane pressure difference of the membrane filtration is 0.4-0.6 MPa, and the feed flow rate of the membrane filtration is 2-5 m / s.

10. The process of claim 7, wherein, The oil cooler has an operating temperature range of 80-200°C. The oil cooler has an operating temperature range of 80-200°C.

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