Method and apparatus for producing high quality low sulfur petroleum coke

Abstract

This invention relates to the field of petrochemical technology, specifically to a method and apparatus for increasing the production of high-quality, low-sulfur petroleum coke. The method includes: subjecting feedstock oil and catalyst to hydrodesulfurization pretreatment; heat-treating the resulting liquid-solid component I; separating and extracting the resulting liquid-solid component II; and coking the obtained coking feedstock to obtain low-sulfur petroleum coke with a sulfur content ≤2 wt%. The catalyst is selected from at least one complex formed by the coordination bonding of an active metal and an organic ligand. The method provided by this invention not only achieves efficient conversion of feedstock oil and increases the production of high-quality petroleum coke, but also broadens the feedstock sources for low-sulfur petroleum coke, realizing the economic added value of feedstock oil, especially high-sulfur, low-quality feedstock oil.

Description

Technical Field

[0001] This invention relates to the field of petrochemical technology, specifically to a method and apparatus for increasing the production of high-quality, low-sulfur petroleum coke. Background Technology

[0002] Petroleum coke is a solid product obtained from delayed coking units in oil refineries and is an irreplaceable raw material for many industries, including glass, steel, and electrolytic aluminum. The quality of petroleum coke is greatly affected by the type of crude oil processed by the refinery; most of the sulfur and impurities in the crude oil are concentrated in the petroleum coke. Based on sulfur content, petroleum coke with a sulfur mass fraction of no more than 3 wt% is called low-sulfur petroleum coke, mainly used in the steel and aluminum industries for electrode manufacturing; petroleum coke with a sulfur content higher than 3 wt% is called high-sulfur coke, an economical fuel that can replace thermal coal, mainly used as fuel in the cement, power, and steel industries. In most countries worldwide, high-sulfur petroleum coke is still primarily used as fuel for power plants; high-quality, low-sulfur petroleum coke is widely used in the steel, aluminum, and carbon industries, significantly increasing its value.

[0003] With the increasing trend towards heavier petroleum resources, my country's imports of crude oil, especially high-sulfur crude oil, are gradually increasing, leading to a corresponding increase in the production of high-sulfur petroleum coke. Reducing the sulfur content of coking feedstock is key to reducing high-sulfur coke production and producing low-sulfur coke. A combined process of residue hydrotreating and delayed coking can address the high sulfur content problem in petroleum coke encountered in delayed coking processes. However, hydrodesulfurization inevitably results in the loss of the effective coke-producing component—residual carbon. How to obtain coking feedstock with high residual carbon content while effectively desulfurizing, thereby meeting the significantly increased demand for low-sulfur coke from downstream industries, is a crucial factor that must be considered during process development.

[0004] CN201110353406.4 discloses a combined process of residue oil hydrotreating and delayed coking. The process involves mixing residue oil, coking wax oil, and hydrogen before feeding them into a hydrotreating unit for reaction. The resulting hydrotreated residue oil and vacuum-pressed wax oil are then mixed or fed into a delayed coking unit along with other conventional feedstocks. The coking products are then separated, with all coking wax oil recycled back to the residue oil hydrotreating unit. This method can produce low-sulfur petroleum coke. However, fixed-bed coking has strict limitations on the asphaltene and metal content of the feedstock.

[0005] CN201110322478.2 discloses a combined process of residue hydrotreating and delayed coking. In this method, the residue hydrotreating employs a fluidized bed hydrotreating process, including: the liquid phase product of the residue feedstock after fluidized bed hydrotreating is directly fed into a coking fractionation tower without fractionation, where it comes into countercurrent contact with the oil and gas generated during coking, washing away the coke powder carried in the high-temperature oil and gas. The light components generated by hydrotreating and coking are discharged together from the unit, while the wax oil and above fractions are recycled back to the delayed coking unit. This method combines fluidized bed residue hydrotreating with delayed coking. However, the widespread application of this process is limited by the extremely limited industrial use of fluidized bed residue hydrotreating units in China.

[0006] Therefore, developing a combined process of residue hydrotreating and delayed coking that can increase the production of high-quality, low-sulfur coke is of great significance for solving the problem of high-sulfur coke disposal, improving resource utilization, and meeting market demand. Summary of the Invention

[0007] The purpose of this invention is to overcome the above-mentioned technical problems and provide a method and apparatus for increasing the production of high-quality low-sulfur petroleum coke. The method employs a specific process to obtain high-quality and high-yield low-sulfur petroleum coke.

[0008] To achieve the above objectives, the first aspect of the present invention provides a method for increasing the production of high-quality low-sulfur coke, the method comprising: subjecting feedstock oil and catalyst to hydrodesulfurization pretreatment, subjecting the obtained liquid-solid component I to heat treatment, subjecting the obtained liquid-solid component II to separation and extraction, subjecting the obtained coking feedstock to coking treatment, and obtaining low-sulfur petroleum coke with a sulfur content ≤2wt%.

[0009] The catalyst is selected from at least one complex formed by the coordination bond between an active metal and an organic ligand.

[0010] Preferably, the method includes the following steps:

[0011] (1) The feed oil and catalyst are subjected to the hydrodesulfurization pretreatment in the presence of hydrogen to obtain the liquid-solid component I and gas I;

[0012] (2) The liquid-solid component I is subjected to the heat treatment to obtain the liquid-solid component II and gas II;

[0013] (3) The liquid-solid component II is separated and extracted to obtain external tail oil, light components and heavy components;

[0014] (4) The heavy components are used as coking raw materials to undergo coking treatment to obtain the low-sulfur petroleum coke;

[0015] The separation and extraction are selected from extraction separation-distillation coupling and distillation cutting.

[0016] A second aspect of the present invention provides an apparatus for increasing the production of high-quality, low-sulfur petroleum coke, the apparatus comprising a reaction unit, a heat treatment unit, a separation and extraction unit, and a coking unit connected in sequence.

[0017] The reaction unit is used to pretreat the feedstock oil and catalyst in the presence of hydrogen for hydrodesulfurization to obtain gas I and liquid-solid component I; the heat treatment unit is used to heat treat the liquid-solid component I to obtain gas II and liquid-solid component II; the separation and extraction unit is used to separate and extract the liquid-solid component II to obtain tail oil, light components and heavy components; the coking unit is used to coke the heavy components as coking feedstock to obtain low-sulfur petroleum coke with a sulfur content ≤2wt%.

[0018] Through the above technical solution, the method provided by the present invention adopts a combination of hydrodesulfurization pretreatment, heat treatment, separation and extraction and delayed coking process, combined with a specific catalyst, to obtain coking feedstock with high residual carbon content while effectively desulfurizing. This method not only achieves efficient conversion of feedstock oil and increases the production of high-quality petroleum coke, but also broadens the feedstock of low-sulfur petroleum coke, realizing the economic added value of feedstock oil, especially high-sulfur inferior feedstock oil.

[0019] Furthermore, the method provided by this invention is also used in conjunction with a specific catalyst. In a hydrogen-rich environment, this catalyst exhibits high oil-phase dispersibility and hydrodesulfurization selectivity, enabling the targeted adsorption and desulfurization of sulfur-containing compounds in the feedstock oil, thereby improving the desulfurization effect. In a hydrogen-poor environment, this catalyst also has a dehydrogenation condensation effect, thus obtaining coking feedstock with a higher residual carbon content. This achieves efficient conversion of high-sulfur, low-quality feedstock oil while also increasing the production of high-quality, low-sulfur petroleum coke. Therefore, using the low-sulfur petroleum coke provided by this invention in anode materials expands the source of anode electrode raw materials while ensuring high electrochemical performance. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the device structure for increasing the production of high-quality, low-sulfur petroleum coke provided by the present invention.

[0021] Figure 2 This is a schematic diagram of another device structure for increasing the production of high-quality, low-sulfur petroleum coke provided by the present invention.

[0022] Figure 3 The images show the infrared spectra of catalysts C1-C2 used in the examples.

[0023] Explanation of reference numerals in the attached figures

[0024] I. Reaction Unit; II. Heat Treatment Unit; III. Separation and Extraction Unit; III-1. Extraction and Separation Section; III-2. Distillation Section; III-3. Distillation Cutting Tower; IV. Coking Unit; IV-1. Coking Oven; IV-2. Fractionation Tower; 1. Feed Oil; 2. Catalyst; 3. Hydrogen; 4. Gas I; 5. Liquid-Solid Component I; 6. Gas II; 7. Liquid-Solid Component II; 8. External Residue Oil; 9. Deconsolidated Oil; 10. Light Components; 11. Heavy Components; 12. Low-Sulfur Petroleum Coke; 13. Coking Gas; 14. Coking Naphtha; 15. Coking Diesel Oil; 16. Coking Wax Oil; 17. Gas-Liquid Mixture. Detailed Implementation

[0025] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0026] In this invention, unless otherwise specified, the “top” of the container refers to 0-10% of the container from top to bottom; the “upper part” of the container refers to 10-40% of the container from top to bottom; the “middle part” of the container refers to 40-60% of the container from top to bottom; the “lower part” of the container refers to 60-90% of the container from top to bottom; and the “bottom” of the container refers to 90-100% of the container from top to bottom.

[0027] The first aspect of this invention provides a method for increasing the production of high-quality low-sulfur coke, the method comprising: subjecting feedstock oil and catalyst to hydrodesulfurization pretreatment, subjecting the obtained liquid-solid component I to heat treatment, subjecting the obtained liquid-solid component II to separation and extraction, subjecting the obtained coking feedstock to coking treatment, and obtaining low-sulfur petroleum coke with a sulfur content ≤2wt%.

[0028] The catalyst is selected from at least one complex formed by the coordination bond between an active metal and an organic ligand.

[0029] In some embodiments of the present invention, preferably, the method includes the following steps:

[0030] (1) The feed oil and catalyst are subjected to the hydrodesulfurization pretreatment in the presence of hydrogen to obtain the liquid-solid component I and gas I;

[0031] (2) The liquid-solid component I is subjected to the heat treatment to obtain the liquid-solid component II and gas II;

[0032] (3) The liquid-solid component II is separated and extracted to obtain external tail oil, light components and heavy components;

[0033] (4) The heavy components are used as coking raw materials to undergo coking treatment to obtain the low-sulfur petroleum coke;

[0034] The separation and extraction are selected from extraction separation-distillation coupling and distillation cutting.

[0035] In some embodiments of the present invention, preferably, the feedstock oil has a sulfur content ≥3wt%, an asphaltene content ≥11wt%, a heavy metal content (calculated as Ni and / or V) ≥150ppm, and a kinematic viscosity at 100°C ≥2000 mmHg. 2 / s.

[0036] In this invention, the type of feedstock oil can be selected from a wide range, as long as it meets the above-mentioned limitations. Preferably, the feedstock oil is selected from high-sulfur inferior oil; more preferably, the feedstock oil is selected from at least one of high-sulfur crude oil, high-sulfur deasphalted oil, and high-sulfur vacuum residue.

[0037] In this invention, the hydrodesulfurization pretreatment aims to remove sulfur from the feedstock oil to obtain a liquid-solid component I with low sulfur content.

[0038] In some embodiments of the present invention, preferably, in step (1), the temperature of the hydrodesulfurization pretreatment is 380-440℃, for example, 380℃, 400℃, 410℃, 420℃, 430℃, 440℃, and any value in any range of any two values, preferably 400-430℃.

[0039] In some embodiments of the present invention, preferably, in step (1), the hydrogen partial pressure of the hydrodesulfurization pretreatment is 8-20 MPa, for example, 8 MPa, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, 15 MPa, 16 MPa, 18 MPa, 20 MPa, or any value within a range of any two values, preferably 10-18 MPa. In the present invention, hydrogen partial pressure refers to gauge pressure.

[0040] In some embodiments of the present invention, preferably, in step (1), the volume hourly space velocity (VHSV) of the hydrodesulfurization pretreatment is 0.05-0.6 h⁻¹. -1 For example, 0.05h -1 0.1h -1 0.2h -1 0.3h -1 0.4h -1 0.5h -1 0.6h -1And any value within the range of any two values, preferably 0.1-0.5h. -1 In this invention, volume hourly space velocity (VHSV) refers to the volume hourly space velocity of the feedstock oil.

[0041] In some embodiments of the present invention, preferably, in step (1), the conditions for the hydrodesulfurization pretreatment further include: the concentration of the catalyst, calculated as a metal element, is 200-20000 μg / g, for example, 200 μg / g, 500 μg / g, 1000 μg / g, 2000 μg / g, 5000 μg / g, 8000 μg / g, 10000 μg / g, 15000 μg / g, 20000 μg / g, and any value within the range of any two values, preferably 500-10000 μg / g.

[0042] In some embodiments of the present invention, preferably, in step (1), the hydrodesulfurization pretreatment is carried out in a slurry bed reactor. The slurry bed reactor has a uniform gas-liquid-solid three-phase distribution, and the highly dispersed catalyst is suspended in the liquid medium, enabling effective contact with the hydrogen and oil phases; heat transfer is uniform, the reaction temperature is uniform, and there are no hot spots in the reactor; online loading and unloading of the catalyst is not required, and the catalyst enters the reactor together with the feed oil for reaction.

[0043] In some embodiments of the present invention, preferably, the catalyst has the composition shown in formula (I): MO a [R(COO) x ] b (I), in formula I, M is selected from at least one metallic element from Group VB, Group VIB, Group VIII, and Group IB, and R is selected from C3-C 20 Hydrocarbon group, x is selected from 1, 2, 3, a is selected from positive numbers from 0 to 5, and b is selected from positive numbers from 1 to 6.

[0044] In this invention, unless otherwise specified, in Formula I, a selected positive number from 0 to 5 means that a is selected from a positive number greater than 0 and not greater than 5.

[0045] In this invention, the catalyst is shown in Formula I, where M represents the active metal and R(COO) is the catalyst. x Let R represent the organic ligand, COO represent the coordinating group in the organic ligand, x represent the number of coordinating groups in the organic ligand, a represent the molar ratio of non-coordinated oxygen atoms connected to the active metal M to the total amount of metal, and b represent the molar ratio of the organic ligand to the total amount of metal. That is, the catalyst provided by this invention is selected from at least one complex formed by the active metal and the organic ligand through coordination bonds. The organic ligand comprises a hydrocarbon group and a coordinating group, wherein the coordinating group is a -C(=O)-O group, and forms a coordination bond with the central atom or central ion of the active metal through an oxygen atom.

[0046] According to the present invention, depending on the metal used, the Group VB, Group VIB, Group VIII and Group IB metals with hydrogenation properties in the catalyst of the present invention may be in the form of a central atom or a central ion or a central ion.

[0047] According to the present invention, the catalyst may be a mixture of various different complexes, and the molar ratios a and b of oxygen atoms and organic ligands to the total amount of metal in the catalyst composition are calculated values ​​based on metal content and elemental composition analysis, and therefore may be non-integers.

[0048] In some embodiments of the present invention, more preferably, in Formula I, M is selected from at least one metallic element selected from V, Cr, Mo, W, Fe, Co, Ru, Ni, Cu, and Pd, and R is selected from C4-C. 20 n-alkyl, C4-C 20 Isoalkyl, C5-C 20 Contains cycloalkyl and C6-C 20 Aryl, x is selected from 1 and 2, a is selected from positive numbers from 1 to 3, and b is selected from positive numbers from 2 to 5.

[0049] In some embodiments of the present invention, more preferably, in Formula I, M is selected from at least one metallic element selected from Mo, W, Ni, V, Co, and Fe, and R is selected from C5-C6. 11 n-alkyl, C5-C 11 Isoalkyl, C5-C 12 Contains cycloalkyl and C6-C 12 Aryl.

[0050] In some embodiments of the present invention, the organic ligand in the catalyst is selected from at least one of succinic acid, hexanoic acid, adipic acid, heptanoic acid, octanoic acid, nonanoic acid, ethylhexanoic acid, oleic acid, petroleum ether, salicylic acid, benzoic acid, and phenylacetic acid.

[0051] In some specific embodiments of the present invention, the catalyst includes, but is not limited to, (MoCo)O. 1.27 [(C7H 16 (COO)] 2.45 (Mo) 0.7 Ni 0.3 )O 1.4 [(C7H 16 (COO)] 3.27 、MoO[(i-C7H 16 (COO)] 2.88 wait.

[0052] In some embodiments of the present invention, preferably, the infrared spectrum of the catalyst is in the range of 700-1000 cm⁻¹.-1 It exhibits characteristic vibrational peaks of MO and M=O at the location; and at 1350-1450 cm⁻¹ -1 and 1500-1610cm -1 The position has a characteristic peak indicating coordination between the -C(=O)-O group and the metal M;

[0053] In this invention, unless otherwise specified, the catalyst consists only of a complex and contains no solid support component. However, if desired, the catalyst of this invention may also be used in combination with liquid components capable of dispersing the catalyst, such as organic solvents and organic ligand compounds, to form a composition.

[0054] To reduce production costs while ensuring catalyst performance, the content of active metal in the catalyst can be limited. Preferably, the active metal content (calculated as M) in the catalyst is 5-35 wt%, for example, 5 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt%, 30 wt%, 35 wt%, and any value within any range of any two values, preferably 8-25 wt%, more preferably 10-25 wt%, and even more preferably 10-20 wt%.

[0055] In this invention, the purpose of the heat treatment is that, under a hydrogen-poor environment, the catalyst also has a dehydrogenation and polycondensation effect, thereby obtaining coking feedstock with a higher residual carbon content. While achieving efficient conversion of high-sulfur and low-quality feedstock oil, it can also increase the production of high-quality and low-sulfur petroleum coke.

[0056] In this invention, unless otherwise specified, hydrogen-rich refers to a hydrogen-containing atmosphere; hydrogen-poor refers to an atmosphere containing an inert gas, which includes, but is not limited to, nitrogen, helium, argon, neon, etc., and is preferably nitrogen.

[0057] In some embodiments of the present invention, preferably, the heat treatment is carried out in an air atmosphere or an inert atmosphere, more preferably in an inert atmosphere, which includes and is limited to a nitrogen atmosphere, an argon atmosphere, a helium atmosphere, etc.

[0058] In some embodiments of the present invention, preferably, in step (2), the temperature of the heat treatment is 380-440°C, for example, 380°C, 400°C, 410°C, 420°C, 430°C, 440°C, and any value in the range of any two values, preferably 400-430°C.

[0059] In some embodiments of the present invention, preferably, in step (2), the pressure of the heat treatment is 0.1-4 MPa, for example, 0.1 MPa, 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, and any value in the range of any two values, preferably 1-3 MPa.

[0060] In some embodiments of the present invention, preferably, in step (2), the heat treatment time is 10-120 min, for example, 10 min, 20 min, 40 min, 50 min, 60 min, 80 min, 100 min, 120 min, and any value in any range of any two values, preferably 20-100 min.

[0061] In some embodiments of the present invention, preferably, the liquid-solid component II satisfies: 0 wt% < increase in toluene-insoluble matter ≤ 5 wt%, 0 wt% ≤ decrease in the fraction above 350°C < 15 wt%; more preferably, the liquid-solid component II satisfies: 0 wt% < increase in toluene-insoluble matter ≤ 3 wt%; 0 wt% ≤ decrease in the fraction above 350°C < 10 wt%.

[0062] In this invention, "0wt% < increase in toluene insoluble matter ≤ 5wt%" means that the increase in the content of toluene insoluble matter does not exceed 5wt%; similarly, "0wt% ≤ decrease in the fraction above 350°C < 15wt%" means that the decrease in the content of the fraction above 350°C is less than 15%.

[0063] In some embodiments of the present invention, preferably, the liquid-solid component II further satisfies the following conditions: sulfur content ≤ 2 wt%; residual carbon content ≥ 7 wt%; more preferably, the liquid-solid component II satisfies the following conditions: sulfur content ≤ 1.5 wt%; residual carbon content ≥ 10 wt%.

[0064] In this invention, the separation and extraction aims to remove the catalyst-containing solids from the liquid-solid component II (this part needs to be removed for two reasons: first, it contains almost all the catalyst metal components, and extracting this part allows for catalyst recycling, effectively reducing the amount of catalyst used; second, it also contains metals from the raw material, and removing these metals can effectively reduce the ash content of the petroleum coke; at the same time, it is desirable to retain as many coking components as possible other than metals, which is beneficial to increasing the yield of petroleum coke); simultaneously, a fraction suitable for coking feed is obtained (generally a solids-removing fraction at >350℃). Therefore, the separation and extraction method is selected from extraction separation-distillation coupling and distillation cutting.

[0065] In a specific embodiment of the present invention, preferably, when the separation and extraction is selected from extraction-separation-distillation coupling, the extraction-separation-distillation coupling process includes: contacting the liquid-solid component II with a solvent and performing extraction separation to obtain the external tail oil and the deconsolidated oil; and distilling the deconsolidated oil to obtain the light component and the heavy component.

[0066] In some embodiments of the present invention, more preferably, the extraction and separation conditions include: a temperature of 40-300℃, for example, 40℃, 80℃, 100℃, 120℃, 150℃, 180℃, 200℃, 240℃, 300℃, and any value within the range of any two values, preferably 80-240℃; a pressure of 0.1-6MPa, for example, 0.1MPa, 0.5MPa, 1MPa, 2MPa, 3MPa, 5MPa, 6MPa, and any value within the range of any two values, preferably 0.1-3MPa; and a weight ratio of solvent to the deconsolidated oil of 1-10:1, for example, 1:1, 2:1, 3:1, 4:1, 5:1, 8:1, 10:1, and any value within the range of any two values, preferably 1-5:1.

[0067] In some embodiments of the present invention, it is further preferred that the distillation temperature is ≥330°C, for example, 330°C, 340°C, 350°C, 360°C, 370°C, and any value in the range of any two values, preferably 330-370°C.

[0068] In this invention, a wide range of solvents can be selected, as long as they can remove the solid content (catalyst, heavy metals) from the liquid-solid component II. Preferably, the solvent is selected from at least one of C3-C8 alkanes, C3-C8 olefins, toluene, and light naphtha, and more preferably from C4-C5 alkanes and / or toluene.

[0069] In another embodiment of the present invention, preferably, when the separation and extraction is selected from distillation cutting, the temperature of the distillation cutting is ≥330°C, for example, 330°C, 340°C, 350°C, 360°C, 370°C, and any value in the range of any two values, preferably 330-370°C.

[0070] In this invention, the light component is selected from liquid phase components with a distillation range <330°C; the heavy component contains the main easily coking components in the hydrodesulfurization products. Preferably, the sulfur content of the coking feedstock is ≤1.5wt%, for example, 0.1wt%, 0.5wt%, 0.8wt%, 1wt%, 1.2wt%, 1.5wt%, and any value within any range of any two values, preferably 0.5-1.2wt%; the residual char content is ≥8wt%, for example, 8wt%, 10wt%, 12wt%, 15wt%, 18wt%, 20wt%, and any value within any range of any two values, preferably 10-20wt%; and the distillation range is ≥330°C.

[0071] In some embodiments of the present invention, preferably, the method further includes: returning a portion of the external tail oil for the hydrodesulfurization pretreatment; and discharging the remaining portion of the external tail oil. This arrangement can further improve the conversion rate of the feedstock oil and reduce the catalyst cost.

[0072] In this invention, the weight ratio of a portion of the external tail oil to the remaining portion of the external tail oil has a wide range of selection, that is, the weight ratio of a portion of the external tail oil to the remaining portion of the external tail oil is 0-100:100-0. The above weight ratio selection is adjusted based on specific working conditions.

[0073] In some embodiments of the present invention, preferably, in step (4), the conditions for the coking treatment include: a temperature of 500-600℃, for example, 500℃, 520℃, 550℃, 580℃, 600℃, and any value within the range of any two values; a pressure of 0.15-0.3MPa, for example, 0.15MPa, 0.2MPa, 0.25MPa, 0.3MPa, and any value within the range of any two values; a time of 1-5h; and a cycle ratio of 0-1, for example, 0, 0.2, 0.5, 0.6, 0.8, 1, and any value within the range of any two values.

[0074] In this invention, the temperature of coking treatment refers to the outlet temperature of the coking furnace; the pressure of coking treatment refers to the top pressure of the coking furnace; the circulation ratio is the ratio of the circulating oil volume to the fresh feedstock oil volume, and the conventional circulating oil is the heaviest part of the coking distillate oil, which is recycled.

[0075] In some embodiments of the present invention, preferably, the low-sulfur petroleum coke satisfies the following conditions: sulfur content ≤2wt%, volatile matter content ≤12wt%, and ash content ≤0.5wt%.

[0076] In this invention, unless otherwise specified, low-sulfur petroleum coke with a sulfur content ≤2wt% only has requirements for sulfur content, volatile matter content and ash content, but no requirements for metal content.

[0077] Compared to existing technologies that directly feed residual oil into coking, the method provided by this invention uses hydrodesulfurization pretreatment, which reduces the sulfur content in petroleum coke, but also reduces the overall petroleum coke yield. By adding a heat treatment step and controlling the coking conditions, the sulfur content can be reduced while the overall petroleum coke yield can be increased.

[0078] A second aspect of the present invention provides a schematic diagram of an apparatus for increasing the production of high-quality, low-sulfur petroleum coke, as shown in the figure. Figure 1-2 As shown, by Figure 1-2 It is known that the device includes a reaction unit I, a heat treatment unit II, a separation and extraction unit III, and a coking unit IV connected in sequence;

[0079] The reaction unit I is used to perform hydrodesulfurization pretreatment on feedstock oil 1 and catalyst 2 in the presence of hydrogen 3 to obtain gas I 4 and liquid-solid component I 5; the heat treatment unit II is used to perform heat treatment on liquid-solid component I 5 to obtain gas II 6 and liquid-solid component II 7; the separation and extraction unit III is used to separate and extract liquid-solid component II 7 to obtain tail oil 8, light component 10 and heavy component 11; the coking unit IV is used to coke the heavy component 11 as coking feedstock to obtain low-sulfur petroleum coke 12 with a sulfur content ≤2wt%.

[0080] In this invention, preferably, as follows: Figure 1 As shown, the separation and extraction unit III includes an extraction and separation section III-1 and a distillation section III-2 connected in sequence. The extraction and separation section III-1 is used to contact the liquid-solid component II 7 with the solvent and perform extraction and separation, obtaining external tail oil 8 at the bottom of the column and desolidified oil 9 at the top of the column. The distillation section III-2 is used to distill the desolidified oil 9, obtaining light component 10 at the top of the column and heavy component 11 at the bottom of the column.

[0081] In this invention, preferably, as follows: Figure 2 As shown, the separation and extraction unit III is selected from the distillation cutting tower III-3, which is used to distill and cut the liquid-solid component II 7, obtain the external tail oil 8 at the bottom of the tower, obtain the light component 10 at the top of the tower, and obtain the heavy component 11 in the side stream of the tower.

[0082] In this invention, more preferably, such as Figure 1-2 As shown, the bottom of the extraction unit III is connected to the reaction unit I, which is used to return a portion of the external tail oil and perform the hydrodesulfurization pretreatment.

[0083] In this invention, such as Figure 1 As shown, preferably, the coking unit IV includes: a coking furnace IV-1 and a fractionation tower IV-2 connected in sequence. The coking furnace IV-1 is used to coke the heavy component 11 as coking raw material, and low-sulfur petroleum coke 12 is obtained at the bottom of the tower, and a gas-liquid mixture 17 is obtained at the top of the tower. The fractionation tower IV-2 is used to fractionate the gas-liquid mixture 17 to obtain coking gas 13, coking naphtha 14, coking diesel oil 15, and coking wax oil 16.

[0084] In this invention, such as Figure 1-2 As shown, reaction unit I is selected from a slurry bed reactor, with gas I 4 obtained at the top of the column and liquid-solid component I 5 obtained at the bottom of the column; heat treatment unit II is selected from a reactor, including but not limited to a fixed bed reactor, high-pressure reactor, etc., with gas II 6 obtained at the top of the column and liquid-solid component II 7 obtained at the bottom of the column; extraction separation section III-1 is selected from a solid-liquid separation device, including but not limited to an extraction column; distillation section III-2 includes but is not limited to a distillation column; distillation cutting column III-3 includes but is not limited to a distillation column.

[0085] This invention provides a schematic diagram of an apparatus for increasing the production of high-quality, low-sulfur petroleum coke, as shown below. Figure 1 As shown, the device includes a reaction unit I, a heat treatment unit II, a separation and extraction unit III, and a coking unit IV connected in sequence.

[0086] Among them, reaction unit I is selected from slurry bed reactor, which is used to perform hydrodesulfurization pretreatment on feedstock oil 1 and catalyst 2 in the presence of hydrogen 3, and gas I 4 is obtained at the top of the tower and liquid-solid component I 5 is obtained at the bottom of the tower.

[0087] Heat treatment unit II is selected from a fixed-bed reactor and is used to heat treat the liquid-solid component I 5, with gas II 6 obtained at the top of the column and liquid-solid component II 7 obtained at the bottom of the column;

[0088] The separation and extraction unit III includes an extraction separation section III-1 and a distillation section III-2 connected in sequence. The extraction separation section III-1 is selected from a solvent extraction tower and is used to contact the liquid-solid component II 7 with a solvent and perform extraction and separation. The top of the tower yields a desolvated oil 9, and the bottom of the tower yields an external tail oil 8. The distillation section III-2 is selected from a distillation tower and is used to distill the desolvated oil 9. The top of the tower yields a light component 10, and the bottom of the tower yields a heavy component 11.

[0089] The coking unit IV includes a coking furnace IV-1 and a fractionation tower IV-2 connected in sequence. The coking furnace IV-1 is used to coke the heavy component 11 as coking feedstock, and a gas-liquid mixture 17 is obtained at the top of the tower and low-sulfur petroleum coke 12 is obtained at the bottom of the tower. The fractionation tower IV-2 is used to fractionate the gas-liquid mixture 17, and coking gas 13 is obtained at the top of the tower. Coking naphtha 14 and coking diesel 15 are drawn out from the side of the tower, and coking wax oil 16 is obtained at the bottom of the tower.

[0090] Another schematic diagram of the device structure for increasing the production of high-quality, low-sulfur petroleum coke provided by this invention is shown below. Figure 2 As shown, the device includes a reaction unit I, a heat treatment unit II, a separation and extraction unit III, and a coking unit IV connected in sequence.

[0091] Among them, reaction unit I is selected from slurry bed reactor, which is used to perform hydrodesulfurization pretreatment on feedstock oil 1 and catalyst 2 in the presence of hydrogen 3, and gas I 4 is obtained at the top of the tower and liquid-solid component I 5 is obtained at the bottom of the tower.

[0092] Heat treatment unit II is selected from a fixed-bed reactor and is used to heat treat the liquid-solid component I 5, with gas II 6 obtained at the top of the column and liquid-solid component II 7 obtained at the bottom of the column;

[0093] Separation and extraction unit III is selected from distillation cutting column III-3, which is used to distill and cut the liquid-solid component II 7, and obtain external tail oil 8 from the bottom of the column, light component 10 from the top of the column, and heavy component 11 from the side stream of the column.

[0094] The coking unit IV includes a coking furnace IV-1 and a fractionation tower IV-2 connected in sequence. The coking furnace IV-1 is used to coke the heavy component 11 as coking feedstock, and a gas-liquid mixture 17 is obtained at the top of the tower and low-sulfur petroleum coke 12 is obtained at the bottom of the tower. The fractionation tower IV-2 is used to fractionate the gas-liquid mixture 17, and coking gas 13 is obtained at the top of the tower. Coking naphtha 14 and coking diesel 15 are drawn out from the side of the tower, and coking wax oil 16 is obtained at the bottom of the tower.

[0095] According to a particularly preferred embodiment of the present invention, a method for increasing the production of high-quality, low-sulfur petroleum coke includes the following steps:

[0096] (1) The feedstock oil and catalyst are subjected to hydrodesulfurization pretreatment in the presence of hydrogen to obtain liquid-solid component I and gas I;

[0097] (2) The liquid-solid component I is subjected to heat treatment to obtain liquid-solid component II and gas II;

[0098] (3) The liquid-solid component II is separated and extracted to obtain the tail oil, light component and heavy component;

[0099] (4) The heavy components are used as coking raw materials to obtain low-sulfur petroleum coke with a sulfur content of ≤2wt%.

[0100] The separation and extraction process is selected from extraction separation-distillation coupling and distillation cutting; the extraction separation-distillation coupling process includes: contacting the liquid-solid component II with a solvent and performing extraction separation to obtain the external tail oil and deconsolidated oil, and distilling the deconsolidated oil to obtain the light component and heavy component; the distillation and distillation cutting temperatures are each independently 330-370℃;

[0101] The catalyst has the composition shown in formula (I): MO a [R(COO) x ] b (I), in formula I, M is selected from at least one metallic element from Group VB, Group VIB, Group VIII, and Group IB, and R is selected from C3-C 20 Hydrocarbon group, x is selected from 1, 2, 3, a is selected from positive numbers from 0 to 5, and b is selected from positive numbers from 1 to 6.

[0102] The present invention will be described in detail below through embodiments.

[0103] Feedstock A is a high-sulfur, low-quality feedstock, and its specific properties are shown in Table 1.

[0104] Table 1

[0105]

[0106] The metal content of the obtained products was determined using inductively coupled plasma optical emission spectrometry (ICP-OES) with a SPECTRO ARCOS SOP plasma optical emission spectrometer. The measurement conditions were: the optical chamber was sealed and filled with argon gas, and the observation was performed vertically. The wavelength range was 130-770 nm.

[0107] The elemental composition of the obtained products was determined as follows: the C and H contents were determined by an Italian Cara Erba EA1110 elemental analyzer using the SH 0656 method; the S content was determined by energy dispersive X-ray fluorescence spectrometry (EDXRF) GB17040 method using an Oxford Lab-X3500 benchtop XRF analyzer; and the O content was determined by the O-content method.

[0108] The infrared spectrum of the obtained product was measured using a Thermo Fisher NICOLET IS50 spectrometer, with the measurement conditions being a scanning wavelength from 400 cm⁻¹. -1 -4000cm -1The number of scans was 16. A ZnSe crystal and a mercury cadmium telluride infrared detector were used together to measure the attenuated total reflectance (ATR) of the sample, with a resolution of 4 cm⁻¹. -1 .

[0109] The metal content of catalysts C1-C2 was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The elemental composition of the products was also measured using appropriate methods. Based on the measured metal content and elemental composition results, the compositions of catalysts C1-C2 were determined to be (MoCo)O. 1.27 (C7H 16 COO) 2.45 and(Mo 0.7 Ni 0.3 )O 1.4 (C7H 16 COO) 3.27 The infrared spectra of the above catalysts C1-C2 are as follows: Figure 3 As shown, by Figure 3 It can be seen that the catalyst C1-C2 are all in the range of 700-1000 cm⁻¹ -1 1350-1450cm -1 and 1500-1610cm -1 It exhibits a characteristic peak at this location, specifically between 700 and 1000 cm⁻¹. -1 The location exhibits characteristic vibrational peaks of MO and M=O, at 1350-1450 cm⁻¹. -1 and 1500-1610cm -1 The position shows characteristic peaks of -C(=O)-O groups coordinated with metals, and the peaks are located at 1350-1450 cm⁻¹. -1 A characteristic peak at the location is 1500-1610 cm⁻¹ -1 The distance between the peaks of a characteristic peak at a given location is greater than 145 cm. -1 This indicates that at least some of the complexes of catalyst C1-C2 have a bimetallic monodentate complex structure (ELN:120063-1-2021-7789-043, 120063-1-2021-7789-011; lims:YN-20210308-00604-1).

[0110] Example 1

[0111] (1) The above-mentioned raw material oil A and catalyst C1 (Mo 0.7 Ni 0.3 )O 1.4 [(C7H 16 COO)] 3.27(The active metal content is 12.76 wt%) was subjected to hydrodesulfurization pretreatment in a slurry bed reactor in the presence of hydrogen to obtain gas I and liquid-solid component I. The operating conditions of the above hydrodesulfurization pretreatment are shown in Table 2.

[0112] (2) In a nitrogen atmosphere, the above liquid-solid component I was heat-treated to obtain gas II and liquid-solid component II. The operating conditions, product distribution and properties of the above heat treatment are shown in Table 2.

[0113] (3) The above liquid-solid component II is contacted with solvent and extracted to obtain desolidified oil and external tail oil. The above desolidified oil is distilled at 350°C to obtain light component and heavy component. The heavy component is used as coking feedstock. The above operating conditions and product properties are shown in Table 3.

[0114] (4) The above coking raw materials are subjected to coking treatment to obtain coking gas, coking naphtha, coking diesel oil, coking wax oil and low-sulfur petroleum coke. The operating conditions, product distribution and low-sulfur petroleum coke properties of the above coking treatment are shown in Table 4.

[0115] Example 2

[0116] (1) The above-mentioned raw material oil A and catalyst C2((MoCo)O 1.27 [(C7H 16 (COO)] 2.45 (The active metal content is 11.75 wt%) was subjected to hydrodesulfurization pretreatment in a slurry bed reactor in the presence of hydrogen to obtain gas I and liquid-solid component I. The operating conditions of the above hydrodesulfurization pretreatment are shown in Table 2.

[0117] (2) In a nitrogen atmosphere, the above liquid-solid component I was heat-treated to obtain gas II and liquid-solid component II. The operating conditions, product distribution and properties of the above heat treatment are shown in Table 2.

[0118] (3) The above liquid-solid component II was directly distilled at 350°C, and the resulting heavy component was used as coking raw material. The above operating conditions and product properties are shown in Table 3.

[0119] (4) The above-mentioned heavy components are subjected to coking treatment to obtain coking gas, coking naphtha, coking diesel oil, coking wax oil and low-sulfur petroleum coke. The operating conditions, product distribution and low-sulfur petroleum coke properties of the above coking treatment are shown in Table 4.

[0120] Example 3

[0121] The method is the same as in Example 1, except that...

[0122] In step (1), the conditions for hydrodesulfurization pretreatment are carried out according to the data in Table 2;

[0123] In step (2), gas II and liquid-solid component II are obtained. The product distribution and properties are shown in Table 2.

[0124] In step (3), external tail oil, light components and heavy components are obtained, and the properties of the products are shown in Table 3;

[0125] In step (4), coking gas, coking naphtha, coking diesel oil, coking wax oil and low-sulfur petroleum coke are obtained. The product distribution and properties of low-sulfur petroleum coke are shown in Table 4.

[0126] Example 4

[0127] The method is the same as in Example 1, except that...

[0128] In step (2), the heat treatment conditions are carried out according to the data in Table 2 to obtain gas II and liquid-solid component II. The operating conditions, product distribution and properties of the above heat treatment are shown in Table 2.

[0129] In step (3), external tail oil, light components and heavy components are obtained, and the properties of the products are shown in Table 3;

[0130] In step (4), coking gas, coking naphtha, coking diesel oil, coking wax oil and low-sulfur petroleum coke are obtained. The product distribution and properties of low-sulfur petroleum coke are shown in Table 4.

[0131] Example 5

[0132] The method is the same as in Example 1, except that...

[0133] In step (3), the distillation temperature is set according to the data in Table 3 to obtain external tail oil, light components and heavy components. The operating conditions and product properties of the above distillation are shown in Table 3.

[0134] In step (4), coking gas, coking naphtha, coking diesel oil, coking wax oil and low-sulfur petroleum coke are obtained. The product distribution and properties of low-sulfur petroleum coke are shown in Table 4.

[0135] Example 6

[0136] The method is the same as in Example 1, except that...

[0137] In step (4), the coking conditions are carried out according to the data in Table 4, and coking gas, coking naphtha, coking diesel, coking wax oil and low-sulfur petroleum coke are obtained. The product distribution and properties of low-sulfur petroleum coke are shown in Table 4.

[0138] Comparative Example 1

[0139] The method is the same as in Example 1, except that...

[0140] Step (2) is omitted. That is, the liquid-solid component I obtained in step (1) is directly extracted, separated, distilled, and coked to obtain coking gas, coked naphtha, coked diesel oil, coked wax oil and petroleum coke. The product distribution and low petroleum coke properties are shown in Table 4.

[0141] Table 2

[0142]

[0143] Table 3

[0144]

[0145] Note: * - Weight ratio of solvent to desoldering oil.

[0146] Table 4

[0147]

[0148]

[0149] Note: #- Total yield of low-sulfur petroleum coke = content of >350℃ fraction in liquid-solid component II × content of low-sulfur petroleum coke in coking product. Taking Example 1 as an example, 46.10wt% × 32.6wt% = 15wt%.

[0150] As shown in Table 2-4, compared with Comparative Example 1, the method provided by this invention results in a lower yield of coking wax oil and a higher yield of low-sulfur petroleum coke. At the same time, the sulfur content of the low-sulfur petroleum coke can also meet the standards for high-quality low-sulfur coke, which can be used in anode materials, thus having higher value and meeting environmental protection requirements.

[0151] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for increasing the production of high-quality, low-sulfur petroleum coke, characterized in that, The method includes: (1) pre-treating the feed oil and catalyst with hydrogen in the presence of hydrogen to obtain liquid-solid component I and gas I; (2) The liquid-solid component I is subjected to heat treatment to obtain liquid-solid component II and gas II; (3) The liquid-solid component II is separated and extracted to obtain the tail oil, light component and heavy component; (4) The heavy components are used as coking raw materials for coking to obtain low-sulfur petroleum coke with a sulfur content of ≤2wt%; The separation and extraction are selected from extraction separation-distillation coupling or distillation cutting; The conditions for the hydrodesulfurization pretreatment include: a temperature of 380-440℃; a hydrogen partial pressure of 8-20 MPa; and a volume hourly space velocity of 0.05-0.6 h⁻¹. -1 The concentration of the catalyst, calculated as a metal element, is 200-20000 μg / g. The heat treatment conditions include: a temperature of 380-440℃; a pressure of 0.1-4MPa; and a time of 10-120min; the heat treatment is carried out in an air atmosphere or an inert atmosphere. The conditions for the coking process include: a temperature of 500-600℃; a pressure of 0.15-0.3MPa; a time of 1-5h; and a cycle ratio of 0-1. The catalyst is selected from at least one complex formed by the coordination bond between an active metal and an organic ligand; The catalyst has the composition shown in formula (I): MO a [R(COO) x ] b (I), in formula I, M is selected from at least one metallic element from Group VB, Group VIB, Group VIII, and Group IB, and R is selected from C3-C 20 Hydrocarbon group, x is selected from 1, 2, 3, a is selected from positive numbers from 0 to 5, and b is selected from positive numbers from 1 to 6; The catalyst contains 5-35 wt% active metal, calculated as M.

2. The method according to claim 1, wherein, The conditions for the hydrodesulfurization pretreatment include: a temperature of 400-430℃; a hydrogen partial pressure of 10-18 MPa; and a volume hourly space velocity of 0.1-0.5 h⁻¹. -1 The concentration of the catalyst, calculated as a metal element, is 500-10000 μg / g. And / or, the hydrodesulfurization pretreatment is carried out in a slurry bed reactor; And / or, the feedstock oil has a sulfur content ≥3wt%, an asphaltene content ≥11wt%, a heavy metal content (calculated as Ni and / or V) ≥150ppm, and a kinematic viscosity at 100°C ≥2000 mmHg. 2 / s; And / or, the feedstock oil is selected from high-sulfur, low-quality oil.

3. The method according to claim 1, wherein, The feedstock oil is selected from at least one of high-sulfur crude oil, high-sulfur deasphalted oil, and high-sulfur vacuum residue.

4. The method according to claim 1, wherein, In Formula I, M is selected from at least one metallic element chosen from V, Cr, Mo, W, Fe, Co, Ru, Ni, Cu, and Pd, and R is selected from C4-C. 20 n-alkyl, C4-C 20 Isoalkyl, C5-C 20 Contains cycloalkyl and C6-C 20 Aryl, x is selected from 1 and 2, a is selected from positive numbers from 1 to 3, and b is selected from positive numbers from 2 to 5.

5. The method according to claim 4, wherein, In Formula I, M is selected from at least one metallic element chosen from Mo, W, Ni, V, Co, and Fe, and R is selected from C5-C6. 11 n-alkyl, C5-C 11 Isoalkyl, C5-C 12 Contains cycloalkyl and C6-C 12 Aryl.

6. The method according to claim 1, wherein, The infrared spectrum of the catalyst is in the range of 700-1000 cm⁻¹. -1 It exhibits characteristic vibrational peaks of MO and M=O at the location; and at 1350-1450 cm⁻¹ -1 and 1500-1610cm -1 The position has a characteristic peak indicating coordination between the -C(=O)-O group and the metal M.

7. The method according to claim 1, wherein, The catalyst contains 8-25 wt% active metal, calculated as M.

8. The method according to claim 7, wherein, The catalyst contains 10-25 wt% active metal, calculated as M.

9. The method according to claim 8, wherein, The catalyst contains 10-20 wt% active metal, calculated as M.

10. The method according to claim 1, wherein, The heat treatment conditions include: a temperature of 400-430℃; a pressure of 1-3MPa; and a time of 20-100min. And / or, the heat treatment is carried out in an inert atmosphere.

11. The method according to claim 1, wherein, The liquid-solid component II satisfies the following conditions: 0 wt% < increase in toluene-insoluble matter ≤ 5 wt%; 0 wt% ≤ decrease in the fraction above 350°C < 15 wt%.

12. The method according to claim 11, wherein, The liquid-solid component II satisfies the following conditions: 0 wt% < increase in toluene-insoluble matter ≤ 3 wt%; 0 wt% ≤ decrease in the fraction above 350°C < 10 wt%.

13. The method according to claim 1, wherein, The liquid-solid component II also meets the following requirements: sulfur content ≤ 2wt%; residual carbon content ≥ 7wt%.

14. The method according to claim 13, wherein, The liquid-solid component II meets the following requirements: sulfur content ≤ 1.5 wt%; residual carbon content ≥ 10 wt%.

15. The method according to claim 1, wherein, When the separation and extraction is selected from the extraction-separation-distillation coupling, the extraction-separation-distillation coupling process includes: contacting the liquid-solid component II with a solvent and performing extraction separation to obtain the external tail oil and the deconsolidated oil; and distilling the deconsolidated oil to obtain the light component and the heavy component.

16. The method according to claim 15, wherein, The extraction and separation conditions include: a temperature of 40-300℃; a pressure of 0.1-6MPa; and a weight ratio of solvent to the deconsolidated oil of 1-10:

1.

17. The method according to claim 16, wherein, The extraction and separation conditions include: a temperature of 80-240℃; a pressure of 0.1-3MPa; and a weight ratio of solvent to the deconsolidated oil of 1-5:

1.

18. The method according to claim 15, wherein, The distillation temperature is ≥330℃.

19. The method according to claim 18, wherein, The distillation temperature is 330-370℃.

20. The method of claim 15, wherein, The solvent is selected from at least one of C3-C8 alkanes, C3-C8 olefins, toluene, and light naphtha.

21. The method according to claim 20, wherein, The solvent is selected from C4-C5 alkanes and / or toluene.

22. The method according to claim 1, wherein, When the separation and extraction is selected from distillation cutting, the temperature of the distillation cutting is ≥330℃.

23. The method according to claim 22, wherein, The distillation cutting temperature is 330-370℃.

24. The method according to claim 1, wherein, The sulfur content of the coking feedstock is ≤1.5wt%; the residual carbon content is 10-20wt%.

25. The method according to claim 24, wherein, The sulfur content of the coking feedstock is 0.5-1.2 wt%; the residual carbon content is 10-20 wt%.

26. The method according to claim 1, wherein, The method further includes: returning a portion of the external tail oil and performing the hydrodesulfurization pretreatment; and discharging the remaining portion of the external tail oil.

27. The method according to claim 1, wherein, The method further includes: The gas-liquid mixture obtained from the coking process is fractionated to obtain coking gas, coking naphtha, coking diesel oil, and coking wax oil.

28. The method according to claim 1, wherein, The low-sulfur petroleum coke also meets the following requirements: volatile matter content ≤12wt%, ash content ≤0.5wt%.

29. An apparatus for increasing the production of high-quality, low-sulfur petroleum coke using the method described in any one of claims 1-28, characterized in that, The device includes a reaction unit, a heat treatment unit, a separation and extraction unit, and a coking unit connected in sequence; The reaction unit is used to pretreat the feedstock oil and catalyst with hydrodesulfurization in the presence of hydrogen to obtain gas I and liquid-solid component I; the heat treatment unit is used to heat treat the liquid-solid component I to obtain gas II and liquid-solid component II; the separation and extraction unit is used to separate and extract the liquid-solid component II to obtain tail oil, light components and heavy components; the coking unit is used to coke the heavy components as coking feedstock to obtain low-sulfur petroleum coke with a sulfur content ≤2wt%; The separation and extraction unit includes an extraction and separation section and a distillation section connected in sequence. The extraction and separation section is used to contact the liquid-solid component II with a solvent and perform extraction and separation, obtaining external tail oil at the bottom of the column and desolidified oil at the top of the column. The distillation section is used to distill the desolidified oil, obtaining a light component at the top of the column and a heavy component at the bottom of the column. Alternatively, the separation and extraction unit is selected from a distillation cutting column, which is used to distill and cut the liquid-solid component II, obtaining the outer tail oil at the bottom of the column, the light component at the top of the column, and the heavy component at the side stream of the column.

30. The apparatus according to claim 29, wherein, The reaction unit is selected from a slurry bed reactor.

31. The apparatus according to claim 29, wherein, The bottom of the extraction separation section or distillation cutting tower is connected to the reaction unit, which is used to return a portion of the external tail oil for hydrodesulfurization pretreatment.

32. The apparatus according to claim 29, wherein, The coking unit includes a coking furnace and a fractionation tower connected in sequence. The coking furnace is used to coke the heavy components as coking raw materials, and low-sulfur petroleum coke is obtained at the bottom of the tower and a gas-liquid mixture is obtained at the top of the tower. The fractionation tower is used to fractionate the gas-liquid mixture to obtain coking gas, coking naphtha, coking diesel oil and coking wax oil.

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