A method for reducing the solids content of a slurry bed oil residue

Abstract

The application discloses a method for reducing solid content of slurry bed oil residue, which comprises the following steps: mixing vacuum residue and active metal, and then feeding the mixture into a pretreatment reactor; mixing the pretreated material with an oil-soluble catalyst, and then feeding the mixture into a slurry bed reactor; feeding the mixture from the slurry bed reactor into a solid-liquid separator, and then separating the mixture to obtain an oil phase product; and feeding the oil phase product into a fractionation unit to obtain fractionated oil and purified oil residue. The method combines the active metal treatment process with the slurry bed residue hydrogenation process, effectively reduces the solid content of the oil residue from the slurry bed, realizes purification of the oil residue, and meets the subsequent processing requirements.

Description

Technical Field

[0001] This invention belongs to the field of residue oil processing technology, specifically relating to a method for reducing the solid content of slurry bed oil residue and improving the processability of oil residue. Background Technology

[0002] Crude oil can be distilled at atmospheric pressure and by vacuum distillation to obtain atmospheric residue and vacuum residue, respectively. In most important oilfields in my country, vacuum residue content is relatively high, with a yield of 40%–50% for vacuum residue distilled at temperatures above 500°C. How to fully utilize and rationally process this heavy component is one of the important issues in the petroleum refining industry. However, vacuum residue contains the components with the largest relative molecular mass, highest boiling point, highest heteroatom content, and most complex structure in crude oil. Converting the residue into directly usable fuel oil or chemical products, and effectively removing impurities such as sulfur, nitrogen, metals, and asphaltenes, is a key step in petroleum refining and chemical processing.

[0003] Currently, residue oil is mainly processed through hydrocracking technology to achieve the conversion of heavy components and the removal of impurities. The main processes include fixed-bed residue hydrocracking, fluidized-bed residue hydrocracking, and slurry-bed residue hydrocracking. Fixed-bed and fluidized-bed residue hydrocracking technologies are mature and have been widely applied industrially. Slurry-bed residue hydrocracking, due to its wide range of processable feedstocks and high residue oil conversion rate, is gradually becoming a key technology for refineries to address feedstock degradation and product structure transformation. However, for slurry-bed residue hydrocracking technology, which primarily uses oil-soluble catalysts, the resulting wax oil and unconverted oil typically have poor properties, with high sulfur, nitrogen, and metal content, and most impurities and catalysts accumulate in the tailings.

[0004] CN115739070A discloses a catalyst for slurry bed residue oil hydrogenation and its application method. It proposes an aluminum-molybdenum alloy ball catalyst for slurry bed residue oil hydrogenation. Through the high-temperature environment of the slurry bed reaction process, and under the collision of metals, Mo elements, aided by N and Cl elements in the feed, enter the reaction system in the form of atoms or nanoparticles. This avoids pipe blockage and allows the catalyst to participate in the residue oil hydrogenation reaction, improving residue oil conversion rate, improving the gas distribution in the slurry bed fluidized bed, and making the bubble distribution finer and more uniform.

[0005] CN113736509A discloses a method for treating residual oil from slurry-bed hydrotreating of crude oil. This method uses a combination of solvent oil and porous materials to treat the residual oil. First, the porous material is separated from the mixture, and then the solvent oil is recovered and reused. The porous material can selectively remove heavy metals from the slurry-bed hydrotreating residual oil, while the solvent oil reduces the system viscosity, increases fluidity, and enhances mass transfer. The final metal-free residual oil (the treated residual oil) can be used as feedstock for further processing, such as coking or hydrotreating.

[0006] However, none of the above reports fundamentally solved the problem of high solid content in slurry-bed oil residue, and the post-processing is complex and energy-intensive. Therefore, the problem of high solid content such as residual metals and coke in slurry-bed oil residue remains unresolved. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a method for reducing the solid content of slurry bed oil residue. The method combines an active metal treatment process with a slurry bed residue hydrogenation process to effectively reduce the solid content in the oil residue from the slurry bed, achieving residue purification and making it meet the requirements of subsequent processing.

[0008] This invention provides a method for reducing the solid content of slurry bed oil residue, the method comprising the following: (1) The vacuum residue and active metal are mixed and then fed into the pretreatment reactor. The pretreated material is mixed with the oil-soluble catalyst and then fed into the slurry bed reactor. (2) The mixture from the slurry bed reactor enters the solid-liquid separator, and the oil phase product obtained is entered into the fractionation unit to obtain distillate oil and purified oil residue.

[0009] According to the present invention, in step (1), the sulfur content of the vacuum residue is 3.0wt%~5.6wt%, preferably 3.5wt%~5.0wt%; the nitrogen content is 2200~6000ppm, preferably 2300~4900ppm, by mass; the metal content is 80~350ppm, preferably 80~240ppm, by mass; wherein the metal content is expressed as Ni, V and Mo content.

[0010] According to the present invention, in step (1), the active metal includes one or more of Li, Na and K, preferably Na.

[0011] According to the present invention, in step (1), the mass ratio of the active metal to the vacuum residue is 0.01~0.15, preferably 0.03~0.09.

[0012] According to the present invention, in step (1), the pretreatment reactor is one or more of the following: autoclave reactor, CSTR reactor, and pipeline reactor, preferably a CSTR reactor.

[0013] According to the present invention, in step (1), the reaction conditions of the pretreatment reactor are as follows: reaction temperature is 300~380℃, preferably 320~360℃; hydrogen pressure is 13.0~17.0 MPa, preferably 14.0~16.0 MPa; reaction time is 10~90 min, preferably 20~40 min; hydrogen-to-oil volume ratio is 300~700, preferably 300~500; and stirring speed is 300~1000 rpm, preferably 400~800 rpm.

[0014] According to the present invention, in step (1), the oil-soluble catalyst includes molybdenum dialkyl (aryl) dithiocarbamate (Mo-DTC), molybdenum dialkyl dithiophosphate (Mo-DTP), molybdenum naphthenate (MoNaph), molybdenum isooctanoate, molybdenum hexacarbonyl, etc., preferably molybdenum isooctanoate.

[0015] According to the present invention, in step (1), the oil-soluble catalyst entering the slurry bed reactor accounts for 0.10% to 0.50% of the amount of vacuum residue feedstock, preferably 0.15% to 0.3%.

[0016] According to the present invention, in step (1), the reaction conditions of the slurry bed reactor are: the reaction temperature is 400~460℃, preferably 420~440℃; the hydrogen pressure is 13.0~17.0 MPa, preferably 14.0~16.0 MPa; According to the present invention, in step (2), the solid-liquid separation method is not particularly limited. The solid-liquid separation can be achieved by any of the existing technologies that can achieve solid-liquid separation, including one or more of centrifugal separation, filtration separation and cyclone separation, with centrifugal separation being preferred.

[0017] According to the present invention, in step (3), the sulfur content in the oil residue obtained by the fractionation system is <1.5wt%, preferably 0.5~1.2wt%; nitrogen content is <4500ppm, preferably 2500~3800ppm; metal content is <420ppm, preferably 160~290ppm; wherein, the metal content is calculated based on the total content of Ni, V and Mo; and the solid content is <4.0wt%, preferably <3.0wt%.

[0018] Compared with the prior art, the advantages of the method for reducing the solid content of slurry bed oil residue of the present invention are as follows: After being treated with active metals, vacuum residue is converted into micron-sized active metal sulfides. These sulfides then enter a slurry bed reactor, where they aggregate and grow under high-temperature conditions. This process removes metals from the slurry bed reactor, generates coke, and enriches residual metal catalysts, thereby reducing the solids content of the slurry bed residue. Attached Figure Description

[0019] Figure 1This is a schematic diagram of a method for reducing the solid content of oil residue in a slurry bed.

[0020] Key reference numerals: 1-Vacuum residue; 2-Active metal; 3-Pretreatment reactor; 4-Pretreatment material; 5-Oil-soluble catalyst; 6-Mixer; 7-Slurry bed reactor; 8-Mixed product; 9-Solid-liquid separator; 10-Solid mixture; 11-Mixed product oil; 12-Friction system; 13-Oil residue; 14-Distillate oil. Detailed Implementation

[0021] The effects and functions of the method of the present invention are further illustrated below with reference to embodiments and comparative examples, but the following embodiments do not constitute a limitation on the method of the present invention. In the context of the present invention, unless otherwise specified, % refers to mass percentage.

[0022] In the context of this invention, the solid content refers to the percentage of solid mass obtained after mixing and filtering oil residue with solvent oil, out of the total oil residue mass. The solid content is tested using a hot filtration method. A certain amount of oil residue and solvent oil are mixed in a specific ratio, heated to 200°C, filtered through filter paper, dried, and the solids on the filter paper are collected and weighed. The corresponding solid content of the oil residue can then be calculated.

[0023] In this invention, the vacuum residue feedstock used in the examples and comparative examples is vacuum residue from an atmospheric and vacuum distillation unit of a refinery. The vacuum residue has a sulfur content of 5.25 wt%, a nitrogen content of 4610 ppm, and a metal content of 237 ppm, wherein the metal content is expressed as Ni, V, and Mo. Example 1

[0024] In this example, metallic sodium is mixed with vacuum residue and then fed into a pretreatment reactor, with a sodium to vacuum residue mass ratio of 0.03. The reaction temperature in the pretreatment reactor is 320°C, the hydrogen pressure is 14.0 MPa, the reaction time is 20 min, the hydrogen-to-oil volume ratio is 300, and the stirring speed is 400 rpm.

[0025] The pretreated material was mixed with an oil-soluble catalyst and then fed into a slurry bed reactor, where the mass of the oil-soluble catalyst was 0.15% of the mass of the vacuum residue. The reaction temperature in the slurry bed reactor was 420℃, and the hydrogen pressure was 14.0 MPa. The mixed product was then separated in a centrifuge at a speed of 4000 r / min for 20 min, yielding a solid mixture and a mixed product oil.

[0026] The mixed product oil enters the fractionation system for further processing, yielding oil residue with a distillation range >540℃. The oil residue has a sulfur content of 1.1 wt%, a nitrogen content of 3770 ppm, and a metal content of 240 ppm (calculated as total Ni, V, and Mo). The solid content is 2.2 wt%. Example 2

[0027] In this example, metallic sodium is mixed with vacuum residue and then fed into a pretreatment reactor, with a sodium to vacuum residue mass ratio of 0.06. The reaction temperature in the pretreatment reactor is 340°C, the hydrogen pressure is 15.0 MPa, the reaction time is 30 min, the hydrogen-to-oil volume ratio is 400, and the stirring speed is 600 rpm.

[0028] The pretreated material was mixed with an oil-soluble catalyst and then fed into a slurry bed reactor, where the mass of the oil-soluble catalyst was 0.23% of the mass of the vacuum residue. The reaction temperature in the slurry bed reactor was 430℃, and the hydrogen pressure was 15.0 MPa. The mixed product was then separated in a centrifuge at a speed of 4000 r / min for 20 min, yielding a solid mixture and a mixed product oil.

[0029] The mixed product oil enters the fractionation system for further processing, yielding oil residue with a distillation range >540℃. The oil residue has a sulfur content of 0.84 wt%, a nitrogen content of 3130 ppm, and a metal content of 201 ppm (based on the total content of Ni, V, and Mo). The solid content is 1.9 wt%. Example 3

[0030] In this example, metallic sodium is mixed with vacuum residue and then fed into a pretreatment reactor, with a sodium to vacuum residue mass ratio of 0.09. The reaction temperature in the pretreatment reactor is 360°C, the hydrogen pressure is 16.0 MPa, the reaction time is 40 min, the hydrogen-to-oil volume ratio is 500, and the stirring speed is 800 rpm.

[0031] The pretreated material was mixed with an oil-soluble catalyst and then fed into a slurry bed reactor, where the mass of the oil-soluble catalyst was 0.30% of the mass of the vacuum residue. The reaction temperature in the slurry bed reactor was 440℃, and the hydrogen pressure was 16.0 MPa. The mixed product was then separated in a centrifuge at a speed of 4000 r / min for 20 min, yielding a solid mixture and a mixed product oil.

[0032] The mixed product oil enters the fractionation system for further processing, yielding oil residue with a distillation range >540℃. The oil residue has a sulfur content of 0.52 wt%, a nitrogen content of 2540 ppm, and a metal content of 166 ppm (calculated as total Ni, V, and Mo). The solid content is 1.4 wt%. Example 4

[0033] In this example, potassium metal was mixed with vacuum residue and then fed into a pretreatment reactor, with a potassium metal to vacuum residue mass ratio of 0.03. The reaction temperature in the pretreatment reactor was 320°C, the hydrogen pressure was 14.0 MPa, the reaction time was 20 min, the hydrogen-to-oil volume ratio was 300, and the stirring speed was 400 rpm.

[0034] The pretreated material was mixed with an oil-soluble catalyst and then fed into a slurry bed reactor, where the mass of the oil-soluble catalyst was 0.23% of the mass of the vacuum residue. The reaction temperature in the slurry bed reactor was 430℃, and the hydrogen pressure was 14.0 MPa. The mixed product was then separated in a centrifuge at a speed of 4000 r / min for 20 min, yielding a solid mixture and a mixed product oil.

[0035] The mixed product oil enters the fractionation system for further processing, yielding oil residue with a distillation range >540℃. The oil residue has a sulfur content of 0.89 wt%, a nitrogen content of 3350 ppm, and a metal content of 256 ppm (calculated as total Ni, V, and Mo). The solid content is 2.4 wt%. Example 5

[0036] In this example, metallic sodium is mixed with vacuum residue and then fed into a pretreatment reactor, with a sodium to vacuum residue mass ratio of 0.03. The reaction temperature in the pretreatment reactor is 320°C, the hydrogen pressure is 14.0 MPa, the reaction time is 20 min, the hydrogen-to-oil volume ratio is 300, and the stirring speed is 400 rpm.

[0037] The pretreated material was mixed with an oil-soluble catalyst and then fed into a slurry bed reactor, where the mass of the oil-soluble catalyst was 0.30% of the mass of the vacuum residue. The reaction temperature in the slurry bed reactor was 440℃, and the hydrogen pressure was 14.0 MPa. The mixed product was then separated in a centrifuge at a speed of 4000 r / min for 20 min, yielding a solid mixture and a mixed product oil.

[0038] The mixed product oil enters the fractionation system for further processing, yielding oil residue with a distillation range >540℃. The oil residue has a sulfur content of 0.80 wt%, a nitrogen content of 3010 ppm, and a metal content of 288 ppm (calculated as total Ni, V, and Mo). The solid content is 2.9 wt%. Example 6

[0039] In this example, metallic sodium is mixed with vacuum residue and then fed into a pretreatment reactor, with a sodium to vacuum residue mass ratio of 0.06. The reaction temperature in the pretreatment reactor is 340°C, the hydrogen pressure is 15.0 MPa, the reaction time is 30 min, the hydrogen-to-oil volume ratio is 400, and the stirring speed is 600 rpm.

[0040] The pretreated material was mixed with an oil-soluble catalyst and then fed into a slurry bed reactor, where the mass of the oil-soluble catalyst was 0.30% of the mass of the vacuum residue. The reaction temperature in the slurry bed reactor was 440℃, and the hydrogen pressure was 14.0 MPa. The mixed product was then separated in a centrifuge at a speed of 4000 r / min for 20 min, yielding a solid mixture and a mixed product oil.

[0041] The mixed product oil enters the fractionation system for further processing, yielding oil residue with a distillation range >540℃. The oil residue has a sulfur content of 0.66 wt%, a nitrogen content of 2820 ppm, and a metal content of 270 ppm (calculated as total Ni, V, and Mo). The solid content is 2.6 wt%. Comparative Example 1

[0042] In this example, vacuum residue was mixed with an oil-soluble catalyst and then directly fed into a slurry bed reactor, where the oil-soluble catalyst accounted for 0.30% of the mass of the vacuum residue. The reaction temperature in the slurry bed reactor was 440℃, and the hydrogen pressure was 14.0 MPa. The mixed product was then separated in a centrifuge at 4000 r / min for 20 min, yielding a solid mixture and a mixed product oil.

[0043] The mixed product oil enters the fractionation system for further processing, yielding oil residue with a distillation range >540℃. The oil residue has a sulfur content of 2.11 wt%, a nitrogen content of 6240 ppm, and a metal content of 871 ppm (calculated as total Ni, V, and Mo). The solid content is 9.22 wt%.

Claims

1. A method for reducing the solid content of slurry bed oil residue, characterized in that: The method includes the following: (1) The vacuum residue and active metal are mixed and then enter the pretreatment reactor. The pretreated material is mixed with the oil-soluble catalyst and then enters the slurry bed reactor. (2) The mixture from the slurry bed reactor enters the solid-liquid separator, and the oil phase product is separated and enters the fractionation unit to obtain distillate oil and oil residue.

2. The method according to claim 1, characterized in that: In step (1), the sulfur content in the vacuum residue is 3.0wt%~5.6wt%, preferably 3.5wt%~5.0wt%; the nitrogen content is 2200~6000ppm, preferably 2300~4900ppm, by mass; the metal content is 80~350ppm, preferably 80~240ppm, by mass; wherein the metal content is expressed as Ni, V and Mo content.

3. The method according to claim 1, characterized in that: In step (1), the active metal includes one or more of Li, Na and K, preferably Na.

4. The method according to claim 1, characterized in that: In step (1), the mass ratio of the active metal to the vacuum residue is 0.01 to 0.15, preferably 0.03 to 0.

09.

5. The method according to claim 1, characterized in that: In step (1), the pretreatment reactor is one or more of the following: autoclave reactor, CSTR reactor, and pipeline reactor, with CSTR reactor being preferred.

6. The method according to claim 1, characterized in that: In step (1), the reaction conditions of the pretreatment reactor are as follows: reaction temperature is 300~380℃, preferably 320~360℃; hydrogen pressure is 13.0~17.0 MPa, preferably 14.0~16.0 MPa; reaction time is 10~90 min, preferably 20~40 min; hydrogen-to-oil volume ratio is 300~700, preferably 300~500; and stirring speed is 300~1000 rpm, preferably 400~800 rpm.

7. The method according to claim 1, characterized in that: In step (1), the oil-soluble catalyst includes one or more of molybdenum dialkyl (aryl) dithiocarbamate, molybdenum dialkyl dithiophosphate, molybdenum naphthenate, molybdenum isooctanoate, and molybdenum hexacarbonyl, preferably molybdenum isooctanoate.

8. The method according to claim 1, characterized in that: In step (1), the oil-soluble catalyst entering the slurry bed reactor accounts for 0.10% to 0.50% of the amount of vacuum residue feedstock, preferably 0.15% to 0.3%.

9. The method according to claim 1, characterized in that: In step (1), the reaction conditions of the slurry bed reactor are: reaction temperature of 400~460℃, preferably 420~440℃; hydrogen pressure of 13.0~17.0 MPa, preferably 14.0~16.0 MPa.

10. The method according to claim 1, characterized in that: In step (2), the solid-liquid separation includes one or more of centrifugal separation, filtration separation and cyclone separation, with centrifugal separation being preferred.

11. The method according to claim 1, characterized in that: In step (3), the sulfur content in the oil residue is <1.5wt%, preferably 0.5~1.2wt%; the nitrogen content is <4500ppm, preferably 2500~3800ppm; the metal content is <420ppm, preferably 160~290ppm; wherein, the metal content is calculated based on the total content of Ni, V and Mo; the solid content is <4.0wt%, preferably <3.0wt%.

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