Resid alkaline treatment-catalytic cracking combined processing method

Abstract

The application discloses a residual oil alkali metal treatment-catalytic cracking combined processing method, which comprises the following steps: (1) mixing residual oil raw materials and alkali metals into a reactor to perform reaction; (2) performing solid-liquid separation on the material after the reaction in step (1) to obtain a solid-phase product and generated oil; and (3) feeding the generated oil obtained in step (2) into a catalytic cracking device, and performing fractionation on the material after the reaction to obtain dry gas, liquefied gas, catalytic cracking gasoline, catalytic cracking light diesel oil, catalytic cracking heavy distillate oil and coke. The method can produce high-quality low-sulfur gasoline fraction, has a long running cycle, does not need high-temperature and high-pressure conditions and has low hydrogen consumption, thereby effectively improving fuel quality, reducing device running cost, realizing energy saving and consumption reduction.

Description

Technical Field

[0001] This invention belongs to the field of residue oil processing and utilization, and specifically relates to a combined processing method of residue oil alkali metal treatment-catalytic cracking. Background Technology

[0002] With the increasing scarcity of global oil resources and the trend towards heavier and lower-quality crude oil, deep processing technologies for residual oil, represented by the combined process of residual oil hydrotreating and catalytic cracking, have received widespread attention.

[0003] Traditional residue hydrotreating technologies include four process types: fixed-bed, fluidized-bed, moving-bed, and slurry-bed. These technologies offer advantages such as high oil yield and adjustable olefin and aromatic content. However, they suffer from harsh reaction conditions, high hydrogen consumption, and low selectivity for hydrodesulfurization. Therefore, non-traditional hydrotreating technologies have become a research hotspot in the petrochemical field in recent years. Among these, alkali metal removal technology for residue oil does not require high-temperature, high-pressure reaction conditions, nor does it require a catalyst. It has a long operating cycle, high desulfurization selectivity, and exhibits excellent denitrification and demetallization performance, making it a complete replacement for traditional hydrotreating processes.

[0004] The main problems currently existing in catalytic cracking units are high coke yield, low product yield, and poor quality of catalytic cracked light diesel oil.

[0005] CN106701189A discloses a combined process of residue hydrotreating and catalytic cracking. This invention organically combines fixed-bed residue hydrotreating with catalytic cracking. However, fixed-bed residue hydrotreating technology suffers from problems such as easy catalyst deactivation and short operating cycle. Even if the feedstock properties Ni+V < 105 ppm and residual carbon < 15%, the operating cycle is only 1 year, which cannot match the long-term operation (3-5 years) of catalytic cracking units.

[0006] CN103102985A discloses a combined process of residue hydrotreating and catalytic cracking. This invention relates to fluidized bed residue hydrotreating technology. Although this technology allows for online catalyst replacement and has a long operating cycle, as a traditional hydrotreating technology, it still suffers from problems such as high reaction severity and high hydrogen consumption. Furthermore, traditional residue hydrotreating technology has poor desulfurization selectivity, and during deep hydrodesulfurization, it can cause significant saturation of olefins and aromatics, reducing the quality of fuel oil.

[0007] US4713221 discloses a combined process of residue hydrotreating and catalytic cracking, in which the heavy recycle oil from catalytic cracking is recycled to a residue hydrotreating unit, mixed with the residue oil, hydrotreated, and then fed into the catalytic cracking unit. In this invention, the catalytic cracking slurry is not effectively utilized; therefore, this method has limited effectiveness in reducing coke yield and increasing product yield. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a combined processing method for alkali metal treatment and catalytic cracking of residual oil. This method can produce more high-quality, low-sulfur gasoline fractions, has a long operating cycle, does not require high-temperature and high-pressure conditions, and has low hydrogen consumption, thereby effectively improving fuel quality and reducing operating costs, achieving energy conservation and emission reduction.

[0009] A combined processing method for alkali metal treatment and catalytic cracking of residual oil, the method comprising the following steps:

[0010] (1) The residual oil feedstock and alkali metal are mixed and fed into the reactor for reaction;

[0011] (2) The material after the reaction in step (1) is separated into solid-liquid products and oil.

[0012] (3) The generated oil obtained in step (2) enters the catalytic cracking unit, and the reacted materials are fractionated to obtain dry gas, liquefied gas, catalytic cracked gasoline, catalytic cracked light diesel oil, catalytic cracked heavy distillate oil and coke.

[0013] In step (1) of the method of the present invention, the residual oil raw material includes atmospheric residue, vacuum residue or heavy oil from other sources.

[0014] In step (1) of the method of the present invention, the alkali metal includes one or more of lithium (Li), sodium (Na) and potassium (K).

[0015] In step (1) of the method of the present invention, the reactor is a stirred tank reactor with a stirring rate of 300-1500 r / min, preferably 500-1000 r / min.

[0016] In step (1) of the method of the present invention, the residue oil feedstock and alkali metal are mixed and reacted in the presence of hydrogen. The reaction involves desulfurization reaction, denitrification reaction, demetallization reaction and thermal cracking reaction, etc.

[0017] In step (1) of the method of this invention, the reaction operating conditions are as follows: reaction temperature 250-400℃, hydrogen partial pressure 1.0-18.0MPa, alkali metal to raw material sulfur molar ratio 1-5, and hydrogen-to-oil volume ratio 100-1000Nm. 3 / m 3 The preferred operating conditions are: reaction temperature 300-370℃, hydrogen partial pressure 3.0-16.0 MPa, alkali metal to raw material sulfur molar ratio 2-4, and hydrogen-to-oil volume ratio 300-800 Nm. 3 / m 3 .

[0018] In step (2) of the method of the present invention, the separation device includes various types of equipment that can realize solid-liquid separation, such as horizontal screw centrifuge, disc separator, hydrocyclone, and filter separator; the separation device is preferably a horizontal screw centrifuge with a rotation speed of 2500-10000 r / min, preferably 3500-9000 r / min.

[0019] In step (2) of the method of the present invention, the solid product contains substances such as alkali metal sulfides, alkali metal nitrides, and heavy metals.

[0020] In step (2) of the method of the present invention, the solid content in the generated oil is controlled to be 50-500ppm, preferably 1-200ppm, and the acid value of the generated oil is controlled to be less than 1.0mgKOH / g, preferably less than 0.5mgKOH / g.

[0021] In step (2) of the method of the present invention, the solid-liquid separation is performed at least twice. A first solid-liquid separation yields solid product 1 and generated oil 1; an acidic additive is added to generated oil 1 for a second solid-liquid separation to obtain solid product 2 and generated oil 2. The solid content in generated oil 1 is controlled to be 1500-3000 ppm, preferably 1200-2500 ppm; the alkalinity is 15-30 mg KOH / g, preferably 11-20 mg KOH / g. The acidic additive includes one or more of formic acid, hydrochloric acid, trichloroacetic acid, and phosphoric acid. It is preferred that the acidic substance is added under stirring, and more preferably under suitable temperature and stirring conditions. The temperature is generally 100-330℃, preferably 150-300℃. The stirring rate is generally 50-1500 r / min, preferably 150-1200 r / min. The solid content of the resulting oil 2 obtained after secondary solid-liquid separation is controlled to be 50-600 ppm, preferably 1-200 ppm. After adding acidic substances, the acid value of the resulting oil 2 is less than 1.0 mg KOH / g, preferably less than 0.5 mg KOH / g.

[0022] The solid product obtained in step (2) of the method of the present invention is further separated, and the heavy metals are separated and drawn out of the device; the alkali metal sulfides and alkali metal nitrides are regenerated in the regeneration device to generate alkali metals, elemental sulfur and nitrogen, wherein the alkali metals are returned to the reaction zone, and the elemental sulfur and nitrogen are drawn out of the device. The regeneration device is any type of device / process that can realize the regeneration of alkali metals, such as the alkali metal electrolytic regeneration process technology developed by Ceramatec Inc., Salt Lake City, Utah.

[0023] In step (3) of the method of the present invention, the generated oil 2 obtained in step (2) is fed into the catalytic cracking unit alone or mixed with other raw materials. The reacted materials are fractionated to obtain dry gas, liquefied gas, catalytic cracked gasoline, catalytic cracked light diesel oil, catalytic cracked heavy distillate oil and coke.

[0024] In step (3) of the method of the present invention, the catalytic cracking heavy distillate oil can be mixed with the residue feedstock in step (1) and then reacted with alkali metals. Mixing the catalytic cracking heavy distillate with the residue feedstock can reduce its impurity content and improve the catalytic cracking performance of the catalytic cracking heavy distillate oil as catalytic cracking feedstock, thereby increasing the yield of high-quality low-sulfur gasoline and diesel fractions.

[0025] In step (3) of the method of the present invention, the catalytic cracking unit can employ conventional techniques in the art. The catalytic cracking unit can be one or more units, and each unit should include at least one reactor and one regenerator. The catalytic cracking unit is equipped with a fractionation tower, which can be set separately for each unit or shared. The reactor can be of various types of catalytic cracking reactors, preferably a riser reactor.

[0026] In step (3) of the method of the present invention, the catalytic cracking device can be operated under general conditions in the art: reaction temperature 400-700℃, reaction pressure 0.1-0.8MPa, catalyst-to-oil ratio (by weight) 2-60, and contact time between the reactants and the catalyst 0.1-30s. Preferred operating conditions are: reaction temperature 460-550℃, reaction pressure 0.1-0.4MPa, catalyst-to-oil ratio (by weight) 5-20, and contact time between the reactants and the catalyst 0.1-10s.

[0027] In step (3) of the method of the present invention, the catalytic cracking catalyst packed in the catalytic cracking unit includes various types of catalytic cracking catalysts, such as acid-treated clay, silica-alumina catalysts and molecular sieve catalysts such as ZSM-5 type, X type, and Y type.

[0028] In the alkali metal treatment unit for residual oil, residual oil feedstock and / or catalytic cracking heavy distillate undergo desulfurization, denitrification, demetallization, and thermal cracking reactions under the action of alkali metals and hydrogen. Due to the high reactivity of alkali metals, the sulfur, nitrogen, and metal content in the residual oil feedstock can be significantly reduced even under mild conditions. As feedstock for the catalytic cracking unit, it can directly produce high-quality low-sulfur gasoline fractions and significantly reduce the content of sulfur oxides and nitrogen oxides in the catalytic cracking flue gas. In addition, the reduction in metal and nitrogen content can effectively slow down the deactivation of the catalytic cracking catalyst. The catalytic cracking heavy distillate is recycled to the alkali metal hydrotreating reaction zone, which can reduce the viscosity of the residual oil feedstock, improve the dispersion of alkali metals in the reaction system, and thus enhance the reaction rate and impurity removal effect. At the same time, the catalytic cracking heavy distillate can be impurity removed in the alkali metal hydrotreating unit, becoming a better catalytic cracking feedstock, thereby further improving the yield of high-value-added products from catalytic cracking.

[0029] In the separation unit, acidic additives are used to effectively remove residual alkali metals and alkali metal sulfides and other alkaline substances from the oil generated by the alkali metal treatment unit in the residual oil, so as to prevent alkaline substances from entering the catalytic cracking unit and causing deactivation of the acidic catalyst in the catalytic cracking.

[0030] Compared with the prior art, the residue oil processing method of the present invention has the following advantages:

[0031] (1) The combined process of alkali metal treatment and catalytic cracking of residual oil provided by the present invention can produce high-yield high-quality low-sulfur gasoline fractions using residual oil and catalytic cracking heavy distillate oil as raw materials.

[0032] (2) Compared with traditional hydrogenation treatment technology, the alkali metal treatment technology for residue oil has a lower reaction severity, does not require high temperature and high pressure reaction conditions, does not require catalysts, and does not have the problem of waste agent treatment. It can effectively reduce equipment investment and is conducive to energy conservation, consumption reduction and environmental protection.

[0033] (3) The oil produced by the alkali metal treatment unit of the residue oil is treated to remove the alkaline substances such as residual alkali metals and alkali metal sulfides in the oil, thereby preventing alkaline substances from entering the catalytic cracking unit and causing the deactivation of the acid catalyst of the catalytic cracking.

[0034] (4) By hydrogenating and upgrading the feedstock of catalytic cracking, high-quality low-sulfur gasoline fractions can be produced directly, eliminating the need for subsequent gasoline hydrogenation refining and treatment measures for excessive sulfur oxides and nitrogen oxides in catalytic cracking flue gas, thus reducing the types and number of equipment.

[0035] (5) The present invention achieves two objectives by recycling the heavy distillate from catalytic cracking to the alkali metal treatment and upgrading unit of the residue oil for further hydrogenation and upgrading: First, the addition of the heavy distillate from catalytic cracking reduces the viscosity of the residue oil feedstock, which is beneficial to improving the dispersion of alkali metals in the reaction system, thereby improving the reaction rate and the impurity removal effect; Second, the heavy distillate from catalytic cracking is further de-impaired in the alkali metal treatment unit of the residue oil, becoming a better feedstock for catalytic cracking, which can improve the yield of high value-added products.

[0036] (6) Catalytic cracking products are separated into catalytic gasoline, catalytic cracking light diesel oil and catalytic cracking heavy distillate oil, without the need for separate fractionation of catalytic cracking cycle oil and catalytic cracking slurry oil. This simplifies the fractionation tower structure and reduces equipment investment and operating energy consumption. Attached Figure Description

[0037] Figure 1 This is a flow chart of a combined processing method for alkali metal treatment and catalytic cracking of residual oil.

[0038] 1 is the alkali metal treatment unit for residual oil, 2 is the separation unit, 3 is the regeneration unit, 4 is the purification unit, 5 is the separation unit, 6 is the catalytic cracking unit, 7 is the separation unit, 8 is alkali metal, 9 is hydrogen, 10 is residual oil feedstock, 11 is the product of alkali metal treatment of residual oil, 12 is the solid product of alkali metal treatment of residual oil (alkali metal sulfides and alkali metal nitrides), 13 is alkali metal, 14 is the oil produced by alkali metal treatment of residual oil, 15 is acid additive, 16 is the product after purification treatment (oil and alkali metal salt), 17 is the oil produced after purification treatment, 18 is nitrogen, 19 is elemental sulfur, 20 is heavy metal, 21 is hydrogen and hydrogen sulfide, 22 is dry gas, 23 is liquefied petroleum gas, 24 is gasoline, 25 is diesel, 26 is heavy cycle oil, 27 is coke, 28 is alkali metal salt, 29 is catalytic cracking heavy cycle oil after removing catalyst powder, and 30 is catalyst powder. Detailed Implementation

[0039] The method provided by the present invention will be described below with reference to the accompanying drawings. The residue oil feedstock from pipeline 10 is mixed with the catalytic cracking heavy distillate oil from pipeline 29, and then mixed with hydrogen from pipeline 9, alkali metals from pipeline 8, and regenerated alkali metals from pipeline 13 before entering the residue oil alkali metal treatment unit 1 for reaction. The reaction products enter the separator 2 via pipeline 11 for solid / liquid separation. The solid phase products enter the regenerator 3 via pipeline 12, and non-regenerable heavy metals are extracted via pipeline 20. The solid phase alkali metal sulfides and alkali metal nitrides undergo a regeneration reaction to generate metallic sodium, elemental sulfur, and nitrogen. The regenerated metallic sodium is returned to the residue oil alkali metal treatment reactor via pipeline 13, while elemental sulfur and nitrogen are extracted via pipelines 19 and 18, respectively. The resulting oil (resource oil 1) after solid-liquid separation enters the purification treatment unit 4 via pipeline 14, where it reacts with acidic additives from pipeline 15 to obtain hydrogen, hydrogen sulfide, and a solid-liquid mixture. Hydrogen and hydrogen sulfide are extracted via pipeline 21. The solid-liquid mixture enters separation unit 5 via pipeline 16, where it is separated to obtain purified product oil and alkali metal salts. The alkali metal salts are extracted via pipeline 28. The purified product oil (product oil 2) enters catalytic cracking unit 6 via pipeline 17 for cracking reaction. It is then separated by fractionation facilities into dry gas, liquefied petroleum gas (LPG), catalytic gasoline, catalytic cracked light diesel oil, catalytic cracked heavy distillate, and coke. The dry gas, LPG, catalytic gasoline, catalytic cracked light diesel oil, and coke are extracted via pipelines 22, 23, 24, 25, and 27, respectively. The catalytic cracked heavy distillate oil enters separation unit 26 via pipeline 26 to remove catalyst powder, and then returns to the residue alkali metal treatment unit via pipeline 29. The removed catalyst powder is extracted via pipeline 30.

[0040] The following embodiments will further illustrate the method provided by the present invention, but do not limit the present invention.

[0041] The experiments in the examples and comparative examples were conducted in a pilot-scale unit for alkali metal treatment of residual oil and a small-scale riser-type catalytic cracking unit designed in the laboratory. The separation device used was a horizontal screw centrifuge, and the product oil purification device was a reaction tank with a mixing device. The alkali metal used was metallic sodium. The acidic additive used was a mixture of formic acid and phosphoric acid in a 1:1 mass ratio. The catalytic cracking catalyst used was the LC-7 type catalyst produced by Lanzhou Petrochemical Catalyst Plant.

[0042] In the examples and comparative examples, the formula for calculating the single-pass conversion rate of catalytic cracking is: Single-pass conversion rate = [(gas + gasoline + coke) / total feed] * 100%, and the catalyst activity is compared with the conversion rate as the benchmark.

[0043] The residual oil feedstock A used in the examples and comparative examples was taken from the atmospheric and vacuum distillation unit of the refinery, and its properties are shown in Table 1.

[0044] Example 1

[0045] This embodiment employs a combined process of alkali metal treatment and catalytic cracking for the hydroconversion of residual oil. Residue feedstock A, catalytic cracking heavy distillate oil, and hydrogen are mixed, then mixed with metallic sodium, and fed into the alkali metal hydrotreating reaction zone. The reaction product undergoes solid-liquid separation in a horizontal screw centrifuge at 4200 r / min to obtain the modified product oil and a solid phase. The modified product oil is then purified by reacting with an acidic additive in a purification unit to remove alkaline impurities at 250°C and a stirring rate of 800 r / min. Solid impurities are then removed by a horizontal screw centrifuge (8000 r / min) before the product enters the catalytic cracking unit. The acidic additive is added in excess, and the excess is subsequently removed by a water washing unit.

[0046] Comparative Example 1

[0047] This comparative example employs a combined fixed-bed residue hydrotreating and catalytic cracking process for residue hydroconversion. Residue feedstock A, catalytic cracking heavy distillate, and hydrogen are mixed and fed into the fixed-bed residue hydrotreating unit for reaction. The resulting product oil is then fed into the catalytic cracking unit. The fixed-bed catalysts used in industrial applications are commercial catalysts FZC-28, FZC-30, and FZC-41, manufactured by the Fushun Petrochemical Research Institute. The fixed-bed reactor is loaded with catalysts FZC-28, FZC-30, and FZC-41 in a volume ratio of 3:2:1.

[0048] The reaction conditions for alkali metal treatment of residual oil, fixed-bed residual oil hydrotreating, and catalytic cracking are shown in Table 2. The properties of the oil produced by alkali metal treatment and fixed-bed residual oil hydrotreating are shown in Table 3. The product distribution and properties of the catalytic cracking unit are shown in Tables 4 and 5. It can be seen that under mild reaction conditions of 340℃ and 10MPa, the desulfurization rate, demetallization rate, and carbon removal rate of the alkali metal treatment technology are significantly better than those of the oil produced by the fixed-bed residual oil hydrotreating unit. Furthermore, after the oil treated by the alkali metal treatment technology undergoes cracking in the catalytic cracking unit, the gasoline yield is higher, and the sulfur content of the gasoline fraction is lower (26.4ppm). Therefore, the combined process technology of alkali metal treatment and catalytic cracking can fully utilize the advantages of alkali metal treatment technology. This technology has low reaction severity, does not require high-temperature and high-pressure reaction conditions, does not require catalysts, and eliminates waste catalyst treatment issues. It can effectively reduce equipment investment and is conducive to energy conservation, emission reduction, and environmental protection.

[0049] Table 1 Properties of Raw Materials

[0050]

[0051] Table 2 Main operating conditions for alkali metal treatment and catalytic cracking of residual oil

[0052]

[0053] Table 3 Properties of oils produced by alkali metal treatment and fixed-bed hydrotreating of residue oil

[0054]

[0055] Table 4 Product Distribution of Catalytic Cracking Unit

[0056]

[0057] Table 5. Main Properties of Catalytic Cracking Gasoline

[0058]

[0059] Example 2

[0060] This embodiment uses residual oil feedstock A, and the process flow is the same as in Embodiment 1. The speed of the horizontal decanter centrifuge in the primary separation is 4800 r / min. In the secondary separation process, the temperature of the purification treatment device is 300℃, the stirring rate is 1100 r / min, and the speed of the horizontal decanter centrifuge is 8000 r / min.

[0061] Example 2-1

[0062] Compared to Example 2, the oil generated from the alkali metal treatment of the residue oil underwent a single separation process using a horizontal screw centrifuge at a speed of 9000 r / min.

[0063] The reaction conditions for the alkali metal treatment, purification unit, and catalytic cracking of the residue oil are shown in Table 6. The properties of the oil produced by the alkali metal treatment unit are shown in Tables 7 and 8. The catalyst activity after 200 hours is shown in Table 9. Table 9 shows that the catalyst activity of the catalytic cracking in Example 2 after 200 hours of operation is 7.1 percentage points higher than that in Example 2-1. This indicates that the secondary separation process can effectively remove alkaline substances from the oil produced by the alkali metal treatment unit, preventing the alkaline substances from reducing the concentration of acidic centers in the catalyst and thus decreasing catalyst activity.

[0064] Example 3

[0065] This embodiment uses residual oil feedstock A, and the process flow is the same as in Embodiment 1. The speed of the horizontal decanter centrifuge for the primary separation is 3500 r / min. During the secondary separation process, the temperature of the purification treatment device is 180℃, the stirring rate is 300 r / min, and the speed of the horizontal decanter centrifuge is 8000 r / min.

[0066] Example 3-1

[0067] Compared to Example 3, the rotation speed of the horizontal decanter centrifuge for the primary separation was 6300 r / min. The parameters for the secondary separation process were the same as in Example 3.

[0068] As can be seen from Table 8, the increased rotation speed of the horizontal screw centrifuge in the primary separation process of Example 3-1 reduced the solid content of the generated oil 1, but the solid content of the generated oil 2 was slightly higher than that of Example 2. This is because the removal rate of solid phase substances was higher during the primary separation process, resulting in more remaining suspended solids, which is detrimental to the deposition of solid phase substances during the secondary separation process.

[0069] Table 6 Main Operating Conditions for Alkali Metal Processing and Catalytic Cracking of Residue Oil

[0070]

[0071] Table 7 Properties of Oil Generated from Alkali Metal Residue Processing Unit

[0072]

[0073] Table 8 Properties of Oil Generated from Alkali Metal Residue Processing Unit

[0074]

[0075] Table 9. Catalytic cracking catalyst activity after 200 hours of reaction.

[0076] project Example 2 Example 2-1 Example 3 Example 3-1 One-way conversion rate, wt.% 64.3 57.2 61.2 59.8

Claims

1. A residual base metal treatment-catalytic cracking combined processing method, characterized in that: The method includes the following steps: (1) The residual oil feedstock and alkali metal are mixed and fed into the reactor for reaction; (2) The material after the reaction in step (1) is separated into solid-liquid products and oil. In step (2), the solid-liquid separation is performed twice. After the first solid-liquid separation, solid product 1 and product oil 1 are obtained. An acidic additive is added to product oil 1 for a second solid-liquid separation to obtain solid product 2 and product oil 2. The solid content in product oil 1 is controlled to be 1500-3000 ppm and the alkalinity is 15-30 mg KOH / g. The solid content in product oil 2 obtained after the second solid-liquid separation is controlled to be 50-600 ppm and the acidity of product oil 2 after adding the acidic additive is less than 1.0 mg KOH / g. (3) The generated oil 2 obtained in step (2) enters the catalytic cracking unit. The reacted materials are fractionated to obtain dry gas, liquefied gas, catalytic cracked gasoline, catalytic cracked light diesel oil, catalytic cracked heavy distillate oil and coke.

2. The method of claim 1, wherein: In step (1), the residual oil raw materials include atmospheric residue oil and vacuum residue oil.

3. The method of claim 1, wherein: In step (1), the alkali metal includes one or more of lithium (Li), sodium (Na) and potassium (K).

4. The method of claim 1, wherein: In step (1), the reactor is a stirred tank reactor with a stirring rate of 300-1500 r / min.

5. The method of claim 4, wherein: In step (1), the stirring rate is 500-1000 r / min.

6. The method of claim 1, wherein In step (1), the residue oil feedstock and alkali metal are mixed and reacted in the presence of hydrogen.

7. The method of claim 6, wherein: In step (1), the reaction operating conditions are as follows: reaction temperature 250-400℃, hydrogen partial pressure 1.0-18.0MPa, alkali metal to raw material sulfur molar ratio 1-5, and hydrogen-to-oil volume ratio 100-1000Nm. 3 / m 3 .

8. The method of claim 7, wherein: In step (1), the operating conditions are: reaction temperature 300-370℃, hydrogen partial pressure 3.0-16.0MPa, alkali metal to raw material sulfur molar ratio 2-4, and hydrogen-to-oil volume ratio 300-800 Nm. 3 / m 3 .

9. The method of claim 1, wherein: In step (2), the separation device is one of the following: horizontal screw centrifuge, disc separator, hydrocyclone, and filter separator.

10. The method of claim 9, wherein: In step (2), the separation device is a horizontal screw centrifuge with a rotation speed of 2500-10000 r / min.

11. The method of claim 10, wherein: In step (2), the rotational speed is 3500-9000 r / min.

12. The method of claim 1, wherein: In step (2), the solid content in the generated oil 2 is controlled to be 50-500 ppm, and the acid value of the generated oil 2 is adjusted to be less than 1.0 mg KOH / g.

13. The method of claim 1, wherein: The solid content in the generated oil 1 is controlled to be 1500-2500 ppm.

14. The method according to claim 13, characterized in that: The alkalinity of the generated oil 1 is controlled to be 11-20 mg KOH / g.

15. The method of claim 1, wherein: The acidic additives include one or more of formic acid, hydrochloric acid, trichloroacetic acid, and phosphoric acid.

16. The method of claim 15, wherein: Add the acidic additive while stirring.

17. The method of claim 16, wherein: An acidic additive is added at a suitable temperature and under stirring conditions, wherein the temperature is 100-330℃.

18. The method of claim 16, wherein: An acidic additive is added at a suitable temperature and under stirring conditions, wherein the temperature is 150-300℃.

19. The method of claim 16, wherein: The stirring rate is 50-1500 r / min.

20. The method of claim 19, wherein: The stirring rate is 150-1200 r / min.

21. The method of claim 1, wherein: The solid products obtained in step (2) are further separated, and the heavy metals are separated and taken out of the device; the alkali metal sulfides and alkali metal nitrides are regenerated in the regeneration device to generate alkali metals, elemental sulfur and nitrogen, of which the alkali metals are returned to the reaction zone and the elemental sulfur and nitrogen are taken out of the device.

22. The method according to claim 1, characterized in that: In step (3), the generated oil 2 obtained in step (2) is fed into the catalytic cracking unit alone or mixed with other raw materials. The reacted materials are fractionated to obtain dry gas, liquefied gas, catalytic cracked gasoline, catalytic cracked light diesel oil, catalytic cracked heavy distillate oil and coke.

23. The method of claim 1, wherein: The catalytic cracking heavy distillate oil described in step (3) is mixed with the residue oil feedstock in step (1) and then reacted with alkali metals.

24. The method of claim 1, wherein: The operating conditions of the catalytic cracking unit described in step (3) are as follows: reaction temperature 400-700℃, reaction pressure 0.1-0.8MPa, catalyst-to-oil ratio (by weight) 2-60, and contact time between the reaction feedstock and the catalyst 0.1-30s.

25. The method according to claim 24, characterized in that: The operating conditions of the catalytic cracking unit in step (3) are: reaction temperature 460-550℃, reaction pressure 0.1-0.4MPa, catalyst-to-oil ratio (by weight) 5-20, and contact time between the reaction feedstock and the catalyst 0.1-10s.

26. The method of claim 25, wherein: In step (3), the catalytic cracking catalyst packed in the catalytic cracking unit is one or more of the following: clay, ZSM-5 type, X type, and Y type.

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