A method for removing calcium from residual oil

Abstract

The present invention relates to a method for removing calcium from residue oil. The residue oil, water and emulsifier are fully mixed to obtain a mixture, and the obtained mixture enters a fixed-bed residue oil hydrotreating reactor to contact with a fixed-bed residue oil hydrotreating catalyst for reaction. After the reaction effluent is separated, gas, hydrotreated naphtha, hydrotreated diesel and hydrotreated tail oil are obtained. The present invention effectively improves the calcium removal rate of residue oil in the fixed-bed residue oil hydrotreating process, effectively protects the activity of the catalyst at the rear part of the fixed-bed residue oil hydrotreating unit, and thus conveniently and low-costly extends the operation cycle of the fixed-bed residue oil hydrotreating unit.

Description

Technical Field

[0001] The present invention relates to the technical field of residue hydrotreating, and particularly to a method for removing calcium from residue oil. Background Art

[0002] With the increasing heavy and inferior quality of domestic and foreign crude oils, residue hydrotreating technology has been increasingly widely applied. Currently, most industrial residue hydrotreating units adopt the fixed-bed process. However, the fixed-bed residue hydrotreating process also has its own limitations. Among them, the deactivation of the catalyst due to the deposition of metals on the catalyst and the generation of pressure difference in the bed layer are the most common problems, which limit the service life of the catalyst and may even lead to the unplanned shutdown of the residue hydrotreating unit in severe cases.

[0003] In addition to the relatively common Ni and V metals, the contents of Fe and Ca in some residue oil raw materials are also relatively high. Research shows that there is some oil-soluble Fe in the residue oil. Under hydrotreating conditions, this part of Fe is easily converted into FeS and deposited in the gaps between the catalyst particles in the protective reactor bed layer or on the catalyst surface. In addition, under hydrotreating conditions, the calcium-containing compounds in the residue oil undergo hydrodemetallization reaction on the outer surface of the catalyst, and the generated CaS is deposited on the outer surface of the catalyst particles in the form of crystals. The "outer shell" formed by CaS and other metal sulfides and fouling such as coke deposition on the outer surface of the catalyst particles will fall off and fill the voids between the catalyst particles. The fallen "outer shell" further reacts with coke or metal sulfides to cause the catalyst particles to adhere to each other and form lumps. The formation of catalyst lumps increases the flow resistance of oil and hydrogen in the catalyst bed layer, thereby increasing the pressure difference in the reactor. When the pressure difference reaches the maximum allowable value, the unit can only be forced to shut down in advance, and the lumped catalyst is unloaded. Further analysis shows that no Ca is detected inside these lumped waste catalysts, and most of these catalysts still have good reaction activity.

[0004] To solve the above problems, the prior art either adopts the method of adjusting the grading scheme of the hydrotreating protective agent and the hydrodemetallization agent, or develops a special hydrodemetallization catalyst, or adopts the method of performing switchable operation using a hydrotreating protective reactor.

[0005] CN101684414A discloses a method for hydrotreating high-acid and high-calcium crude oil. The high-acid and high-calcium crude oil undergoes a hydrotreating reaction in the crude oil hydrotreating reaction zone. The obtained hydrotreated crude oil enters the atmospheric column, and is fractionated to obtain atmospheric naphtha, atmospheric diesel oil and atmospheric residue. The atmospheric residue therein enters the residue hydrotreating reaction zone together with hydrogen for a hydrotreating reaction, and the reaction products are separated to obtain hydrotreated naphtha, hydrotreated diesel oil and hydrotreated residue. The hydrotreated residue is a qualified feedstock for catalytic cracking.

[0006] CN107875978A discloses a grading loading method and application of a hydrogenation catalyst. The grading loading method includes at least three fixed-bed reactors connected in series. At least one hydrogenation protective agent and at least one first hydrogenation demetallization agent are loaded in sequence along the material flow direction in the first fixed-bed reactor. Among them, small-particle hydrogenation catalysts are loaded at the end part in the material flow direction. At least one hydrogenation protective agent, at least one first hydrogenation demetallization agent and at least one second hydrogenation demetallization agent are loaded in sequence along the material flow direction in the second fixed-bed reactor. The method of the present invention can process residue oil raw materials with relatively high iron and calcium contents and enable the device to operate in a long cycle.

[0007] CN104119955A discloses a heavy raw material oil treatment device and an application method thereof. The treatment device includes a hydrogenation protection unit, a hydrogenation treatment unit and a catalytic cracking unit connected in series in sequence. Among them, the hydrogenation protection unit includes a main hydrogenation protection reactor and a standby hydrogenation protection reactor connected in parallel, and the volume of the main hydrogenation protection reactor is larger than that of the standby hydrogenation protection reactor. The present invention is particularly suitable for processing residue oil raw materials that are likely to cause pressure drop, such as residue oil with a high calcium content, when processing heavy raw material oil. Summary of the Invention

[0008] The present invention is to solve the problem that when the calcium content in the residue oil raw material is too high, it is easy to affect the operation cycle of the fixed-bed residue oil hydrogenation device. The present invention provides a convenient and low-cost residue oil decalcification method.

[0009] The method provided by the present invention includes:

[0010] (l) The residue oil, water and emulsifier are fully mixed in a buffer tank provided with a mixer to obtain a mixture. Based on the weight of the mixture, the weight fraction of water is 1% - 20%, and the weight ratio of the emulsifier to water is 0.5 - 10:100;

[0011] (2) The mixture obtained in step (1) enters a fixed-bed residue oil hydrogenation reactor and reacts with a fixed-bed residue oil hydrogenation catalyst in the presence of hydrogen. The reaction effluent enters a hot high-pressure separator and is separated into a first gas-phase stream and a first liquid-phase stream;

[0012] (3) The first gas-phase stream from step (2) enters a cold high-pressure separator and is separated into a second gas-phase stream, a second liquid-phase stream and acidic water;

[0013] (4) The first liquid-phase stream from step (2) and the second liquid-phase stream from step (3) enter a fractionating tower together for fractionation to obtain gas, hydrotreated naphtha, hydrotreated diesel and hydrotreated tail oil.

[0014] In the present invention, the residue oil is atmospheric residue oil and / or vacuum residue oil, wherein the Ca content in the residue oil is at least 8 μg / g, preferably higher than 15 μg / g.

[0015] In one embodiment of the present invention, in the mixture obtained in step (1), based on the weight of the mixture, the weight fraction of water is 3% - 12%.

[0016] The inventors of the present invention have found through research that the additionally added water has a certain pore-expanding effect on the fixed-bed residue oil hydrogenation catalyst. During the hydrogenation process, it has an obvious promoting effect on hydrodemetallization, especially on the effect of calcium removal. In addition, the present invention optimizes the amount of water added. On the one hand, if the amount of water is too small, the effect of calcium removal is not obvious. On the other hand, adding too much water will have an adverse effect on the strength of the fixed-bed residue oil hydrogenation catalyst.

[0017] In the present invention, an emulsifier is added to the water, and a mixer is provided in the buffer tank, which can make the dispersion of water in the residue oil more uniform and the calcium removal effect better.

[0018] In one embodiment of the present invention, in the mixture obtained in step (1), the weight ratio of the emulsifier to water is 1.5 - 5:100.

[0019] In one embodiment of the present invention, the role of the emulsifier in step (1) is to make the residue oil and water mix evenly; the emulsifier is a single surfactant or a mixture composed of a surfactant and other additives. The elements constituting the emulsifier are C, H, and at least any one of S, N, and O. Based on the mass of the emulsifier, the sum of the mass fractions of S element and N element is 0 - 10%, preferably 0 - 5%.

[0020] In the present invention, the emulsifier can be commercially available commercial grades, and can be used alone or in combination of several emulsifiers, but the elements contained therein can only be limited to C, H, S, N, and O to ensure that no new elements are introduced into the system.

[0021] Preferably, the emulsifier includes one or more of sorbitan monooleate, sorbitan monostearate, polyoxyethylene sorbitan fatty acid ester, and alkylphenol polyoxyethylene ether.

[0022] In one embodiment of the present invention, the process conditions of the fixed-bed residue oil hydrogenation reactor are: hydrogen partial pressure 5.0 MPa - 22.0 MPa, reaction temperature 330 °C - 450 °C, liquid hourly space velocity 0.1 h -1 ~3.0 h -1 、hydrogen-oil ratio 350 - 2000.

[0023] In one embodiment of the present invention, the fixed-bed residue hydrotreating catalyst is a supported catalyst. The active metal components are at least two selected from nickel, cobalt, molybdenum, and tungsten, and the carrier is one or more selected from alumina, silica, and amorphous silica-alumina. Preferably, the active metal components can be a combination of nickel-tungsten, nickel-tungsten-cobalt, nickel-molybdenum, or cobalt-molybdenum; the carrier is preferably alumina.

[0024] In one embodiment of the present invention, the fixed-bed residue hydrotreating catalyst is loaded in a graded manner with two or more fixed-bed residue hydrotreating catalysts; a hydrotreating protective agent, a hydrodemetallization agent, a hydrodesulfurization agent, an optional hydrodecarbon residue agent, and an optional hydrodenitrogenation agent are loaded in sequence along the reaction fluid flow direction.

[0025] In the present invention, "optional" means that the corresponding catalyst is optional, not essential. That is, according to the raw material and product requirements, the hydrodecarbon residue agent may or may not be present; similarly, the hydrodenitrogenation agent may or may not be present.

[0026] In the present invention, after the reaction effluent obtained from the fixed-bed residue hydrotreating reactor is subjected to gas-liquid separation, the obtained liquid-phase stream enters the fractionation tower for fractionation. In one embodiment of the present invention, before the first liquid-phase stream and the second liquid-phase stream enter the fractionation tower, gas-liquid separation is carried out in a low-pressure separator, and the liquid-phase stream separated from the low-boiling gas and acidic water enters the fractionation tower. The low-pressure separator is one or more.

[0027] In one embodiment of the present invention, the acidic water separated by the cold high-pressure separator in step (3) and the acidic water separated by the low-pressure separator enter the water treatment unit for sewage treatment. In one embodiment of the present invention, the treated water obtained can be recycled to step (1) to be mixed with the residue oil.

[0028] In the present invention, the fractionation tower separates gas, hydrotreated naphtha, hydrotreated diesel, and hydrotreated tail oil. The obtained hydrotreated naphtha can be used as a raw material for a reforming unit or an ethylene unit, the obtained hydrotreated diesel is a blending component of diesel products, and the boiling range of the obtained hydrotreated tail oil is >350 °C, and it can all be used as the feed for a heavy oil fluid catalytic cracking unit.

[0029] The method of the present invention effectively improves the decalcification rate of high-calcium residue oil during fixed-bed residue hydrotreating by adding water, not only avoids the caking of the fixed-bed residue hydrotreating catalyst and the increase in the reactor pressure drop, but also effectively protects the activity of the catalyst at the rear of the fixed-bed residue hydrotreating unit, thereby conveniently and low-costly extending the operation cycle of the fixed-bed residue hydrotreating unit, and has high economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of one embodiment of the method for residue oil decalcification provided by the present invention. Detailed implementation mode

[0031] The present invention will be further described below with reference to the accompanying drawings, but the present invention is not limited thereby.

[0032] Figure 1 It is a schematic diagram of one implementation mode of the method for removing calcium from residual oil provided by the present invention. As Figure 1 shown, the residual oil from pipeline 1, the water and emulsifier from pipeline 2 enter the buffer tank 3 for full mixing. The obtained mixture is mixed with the hydrogen from pipeline 13 and then enters the fixed-bed residual oil hydrogenation reactor 5 through pipeline 4. The reaction takes place under the action of the fixed-bed residual oil hydrogenation catalyst. The reaction effluent enters the hot high-pressure separator 7 through pipeline 6 for gas-liquid separation, and the first gas-phase stream and the first liquid-phase stream are separated. The first gas-phase stream enters the cold high-pressure separator 9 through pipeline 8 for further gas-liquid separation, and the second gas-phase stream, the second liquid-phase stream and the acidic water are separated. The second gas-phase stream removes H 2 S and then enters the recycle hydrogen compressor 11 through pipeline 10. After boosting the pressure, it is mixed with the fresh hydrogen from pipeline 12 and then mixed with the residual oil mixture through pipeline 13. The acidic water separated from the cold high-pressure separator 9 is discharged from the device through pipeline 21. The first liquid-phase stream obtained from the hot high-pressure separator 7 is mixed with the second liquid-phase stream obtained from the cold high-pressure separator 9 through pipeline 14, and then enters the fractionating tower 16 through pipeline 15. Gas, hydrotreated naphtha, hydrotreated diesel and hydrotreated tail oil are separated. Among them, the gas, hydrotreated naphtha and hydrotreated diesel are sent out of the device through pipelines 17, 18 and 19 respectively. The hydrotreated tail oil enters the fluid catalytic cracking unit through pipeline 20.

[0033] The present invention will be further described below with reference to the embodiments, but the present invention is not limited thereby.

[0034] The residual oil hydrogenation tests of the examples and comparative examples were carried out in a fixed-bed double-tube reactor. A hydrogenation protective agent and a hydrogenation demetallization catalyst were loaded in the first reactor (referred to as the first reactor for short), and a hydrogenation desulfurization catalyst was loaded in the second reactor (referred to as the second reactor for short). The loading volume ratio of the three was 1:4:6. The commercial brand of the hydrogenation protective agent was RG-30B, the commercial brand of the hydrogenation demetallization catalyst was RDM-32, and the commercial brand of the hydrogenation desulfurization catalyst was RMS-30, all produced by Zibo Qimao Catalyst Co., Ltd.

[0035] Example 1

[0036] Residuum A, water and an emulsifier are fully mixed in a buffer tank equipped with a mixer to obtain a mixture. The obtained mixture successively enters a first reactor and a second reactor, and the reaction effluent enters a hot high-pressure separator to be separated into a first gas-phase stream and a first liquid-phase stream; the first gas-phase stream enters a cold high-pressure separator to be separated into a second gas-phase stream, a second liquid-phase stream and acidic water; the first liquid-phase stream and the second liquid-phase stream enter a fractionating tower together for fractionation to obtain gas, hydrotreated naphtha, hydrotreated diesel and hydrotreated tail oil.

[0037] The properties of residuum A are shown in Table 1. The weight ratio of residuum to water is 100:3, and the emulsifier is sorbitan monooleate, with a weight ratio to water of 1.5:100. The test conditions are as follows: hydrogen partial pressure 15.0 MPa, temperature of the first reactor 380 °C, temperature of the second reactor 390 °C, hydrogen-oil ratio 700 Nm 3 / m 3 , and the liquid hourly space velocity of residuum is 0.25 h -1 . The properties of the hydrotreated naphtha, hydrotreated diesel and hydrotreated residuum produced are shown in Table 2.

[0038] Example 2

[0039] The residuum raw material, emulsifier, process flow and test conditions used in Example 2 are the same as those in Example 1. Different from Example 1, in Example 2, the weight ratio of residuum A to water is 100:5, and the weight ratio of the emulsifier to water is 2.5:100. After the device runs stably, a sample of hydrotreated residuum is collected every 24 hours, and a total of 3 samples are collected. The calcium content of the hydrotreated residuum is shown in Table 3.

[0040] Example 3

[0041] The process flow and test conditions used in Example 3 are the same as those in Example 1. Different from Example 1, the residuum raw material used in Example 3 is residuum B, whose properties are shown in Table 1. The emulsifier is polyoxyethylene sorbitan fatty acid ester. The weight ratio of residuum B to water is 100:10, and the weight ratio of the emulsifier to water is 4:100. The calcium content of the hydrotreated residuum produced is shown in Table 3.

[0042] Comparative Example 1

[0043] The residuum raw material, process flow and test conditions used in this comparative example are the same as those in Example 1. Compared with Example 1, the raw material oil in this comparative example is only residuum A, and the test conditions are as follows: hydrogen partial pressure 15.0 MPa, temperature of the first reactor 380 °C, temperature of the second reactor 390 °C, hydrogen-oil ratio 700 Nm 3 / m 3 , and the liquid hourly space velocity of residuum is 0.25 h -1 . The calcium content of the hydrotreated residuum produced is shown in Table 3.

[0044] Comparative Example 2

[0045] The residue raw material, process flow and test conditions adopted in this comparative example are the same as those in Example 2. Compared with Example 2, no emulsifier was added in this comparative example, and there was no mixer in the buffer tank where residue A was mixed with water. The test conditions were as follows: hydrogen partial pressure 15.0 MPa, temperature of the first reactor 380 °C, temperature of the second reactor 390 °C, hydrogen-oil ratio 700 Nm 3 / m 3 , and the liquid hourly space velocity of the residue was 0.25 h -1 . A sample of the hydrotreated residue was collected every 24 hours, and a total of 3 samples were collected. The calcium content of the hydrotreated residue is shown in Table 3.

[0046] Comparative Example 3

[0047] The residue raw material, emulsifier, process flow and test conditions adopted in this comparative example are the same as those in Example 2. Compared with Example 2, the only difference is that the weight ratio of residue A to water in this comparative example is 100:0.5. The test conditions were as follows: hydrogen partial pressure 15.0 MPa, temperature of the first reactor 380 °C, temperature of the second reactor 390 °C, hydrogen-oil ratio 700 Nm 3 / m 3 , and the liquid hourly space velocity of the residue was 0.25 h -1 . The calcium content of the generated hydrotreated residue is shown in Table 3.

[0048] Comparative Example 4

[0049] The residue raw material, emulsifier, process flow and test conditions adopted in this comparative example are the same as those in Example 2. Compared with Example 2, the only difference is that the weight ratio of residue A to water in this comparative example is 100:22. The test conditions were as follows: hydrogen partial pressure 15.0 MPa, temperature of the first reactor 380 °C, temperature of the second reactor 390 °C, hydrogen-oil ratio 700 Nm 3 / m 3 , and the liquid hourly space velocity of the residue was 0.25 h -1 . The calcium content of the generated hydrotreated residue is shown in Table 3.

[0050] Comparative Example 5

[0051] The residue raw material, emulsifier, process flow and test conditions adopted in this comparative example are the same as those in Example 2. Compared with Example 2, the only difference is that the weight ratio of the emulsifier to water in this comparative example is 12:100. The test conditions were as follows: hydrogen partial pressure 15.0 MPa, temperature of the first reactor 380 °C, temperature of the second reactor 390 °C, hydrogen-oil ratio 700 Nm 3 / m 3 , and the liquid hourly space velocity of the residue was 0.25 h -1 . The calcium content of the generated hydrotreated residue is shown in Table 3.

[0052] Comparative Example 6

[0053] The residue raw material, emulsifier, process flow, and test conditions used in this comparative example are the same as those in Example 2. Compared with Example 2, the only difference is that the weight ratio of the emulsifier to water in this comparative example is 0.3:100. The test conditions are as follows: hydrogen partial pressure 15.0 MPa, the temperature of the first reactor 380 °C, the temperature of the second reactor 390 °C, hydrogen-oil ratio 700 Nm 3 / m 3 , and the liquid hourly space velocity of the residue is 0.25 h -1 . The calcium content of the produced hydrogenated residue is shown in Table 3.

[0054] Comparative Example 7

[0055] The residue raw material, process flow, and test conditions used in this comparative example are the same as those in Example 3. Compared with Example 3, the raw material oil in this comparative example is only residue B, and the test conditions are as follows: hydrogen partial pressure 15.0 MPa, the temperature of the first reactor 380 °C, the temperature of the second reactor 390 °C, hydrogen-oil ratio 700 Nm 3 / m 3 , and the liquid hourly space velocity of the residue is 0.25 h -1 . The calcium content of the produced hydrogenated residue is shown in Table 3.

[0056] As can be seen from Table 3, the calcium contents of the hydrogenated residues in Examples 1 to 2 are 13.3 μg / g and 11.6 μg / g (average value of three samples) respectively, and the decalcification rates are 10.2 and 16.5 percentage points higher than that of Comparative Example 1 respectively. The decalcification rate of Example 3 is 8.5 percentage points higher than that of Comparative Example 7, indicating that in different raw materials, Ca in the raw materials can be effectively removed by adding water.

[0057] As can be seen from Table 3, the Ca contents of the three samples in Example 2 are relatively stable, with a maximum difference of 0.4 μg / g, while the calcium contents of the three hydrogenated residue samples in Comparative Example 2 without adding emulsifier and without mixer vary greatly, indicating that water and residue cannot be mixed evenly, resulting in unstable product properties.

[0058] As can be seen from Example 2, Comparative Example 3, and Comparative Example 4, if the addition amount of water is not within the range, good technical effects cannot be achieved. If the addition amount is too small, the technical effects cannot be reflected, and if the addition amount is too large, the catalyst structure will be damaged, thus reducing the technical effects.

[0059] As can be seen from Example 2, Comparative Example 5, and Comparative Example 6, if the addition amount of the emulsifier is not within the range, good technical effects cannot be achieved. If the addition amount is too small, the residue and water cannot be mixed well, and if the addition amount is too large, the reaction space velocity will increase, reducing the reaction efficiency, thus reducing the technical effects. Moreover, too much addition of the emulsifier is likely to cause foaming in the high-pressure separator, thus affecting the operation of the device.

[0060] Table 1 Properties of residue raw materials

[0061] Residuum A Residuum B CCR, wt% 10.99 11.20 S, wt% 1.28 2.10 N, ppm 3300 6100 Ni+V, ppm 90.6 53.2 Ca, ppm 26.6 124

[0062] Table 2 Properties and Yields of the Hydrogenation Products in Example 1

[0063]

[0064]

[0065] *Based on the residue feedstock.

[0066] Table 3 Properties of the Residue Feedstock and Hydrotreated Residue

[0067] Ca content, ppm Decalcification rate, % Example 1 13.3 50.2 Example 2-1 11.5 56.8 Example 2-2 11.8 55.6 Example 2-3 11.4 57.1 Example 3 7.9 93.6 Comparative Example 1 16.0 40.0 Comparative Example 2-1 15.0 43.6 Comparative Example 2-2 10.5 60.5 Comparative Example 2-3 13.0 51.1 Comparative Example 3 15.5 41.7 Comparative Example 4 14.8 44.4 Comparative Example 5 14.2 46.6 Comparative Example 6 14.5 45.5 Comparative Example 7 18.5 85.1

Claims

1. A method for removing calcium from residual oil, comprising: (1) Residual oil, water and an emulsifier are fully mixed in a buffer tank equipped with a mixer to obtain a mixture. Based on the weight of the mixture, the weight fraction of water is 1% - 20%, and the weight ratio of the emulsifier to water is 0.5 - 10:100; (2) The mixture obtained in step (1) enters a fixed - bed residue hydro - treatment reactor and reacts in the presence of hydrogen in contact with a fixed - bed residue hydro - treatment catalyst. The reaction effluent enters a hot high - pressure separator and is separated into a first gas - phase stream and a first liquid - phase stream. The fixed - bed residue hydro - treatment catalyst is a supported catalyst, the active metal components are at least two selected from nickel, cobalt, molybdenum, and tungsten, and the carrier is one or more selected from alumina, silica, and amorphous silica - alumina; (3) The first gas - phase stream from step (2) enters a cold high - pressure separator and is separated into a second gas - phase stream, a second liquid - phase stream, and acidic water; (4) The first liquid - phase stream from step (2) and the second liquid - phase stream from step (3) enter a fractionating tower for fractionation to obtain gas, hydrotreated naphtha, hydrotreated diesel, and hydrotreated tail oil.

2. The method according to claim 1, characterized in that, the Ca content in the residual oil is at least 8 μg / g.

3. The method according to claim 1, characterized in that, the Ca content in the residual oil is higher than 15 μg / g.

4. The method according to claim 1, characterized in that, in the mixture obtained in step (1), based on the weight of the mixture, the weight fraction of water is 3% - 12%.

5. The method according to claim 1, characterized in that, in the mixture obtained in step (1), the weight ratio of the emulsifier to water is 1.5 - 5:

100.

6. The method according to claim 1, characterized in that, the function of the emulsifier in step (1) is to make the residual oil and water mix evenly; the emulsifier is a single surfactant or a mixture composed of a surfactant and other additives. The elements constituting the emulsifier are C, H, and at least one element among S, N, and O. Based on the mass of the emulsifier, the sum of the mass fractions of S element and N element is 0 - 10%.

7. The method according to claim 6, characterized in that, based on the mass of the emulsifier, the sum of the mass fractions of S element and N element is 0 - 5%.

8. The method according to claim 6, characterized in that, the emulsifier includes one or more of sorbitan monooleate, sorbitan monostearate, polyoxyethylene sorbitan fatty acid ester, and alkylphenol polyoxyethylene ether.

9. The method according to claim 1, characterized in that, The process conditions of the fixed-bed residue hydrotreating reactor are as follows: hydrogen partial pressure is 5.0 MPa to 22.0 MPa, reaction temperature is 330 °C to 450 °C, liquid hourly space velocity is 0.1 h -1 to 3.0 h -1 , and hydrogen-oil ratio is 350 to 2000.

10. The method according to claim 1, characterized in that, the fixed - bed residue hydro - treatment catalyst is loaded in a graded manner with two or more fixed - bed residue hydro - treatment catalysts; a hydrogenation protective agent, a hydrogenation demetallization agent, a hydrogenation desulfurization agent, an optional hydrogenation decarbonization agent, and an optional hydrogenation denitrogenation agent are loaded in sequence along the reaction flow direction.

11. The method according to claim 1, characterized in that, Before the first liquid-phase logistics and the second liquid-phase logistics enter the fractionating column, gas-liquid separation is carried out in a low-pressure separator, and the liquid-phase logistics separated into low-pressure gas and acidic water enter the fractionating column.

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