Mixed processing method of high-sulfur crude oil and high-acid crude oil

Abstract

The present invention discloses a method for processing a mixture of high-sulfur crude oil and high-acid crude oil, comprising the following steps: (1) pre-treating the high-sulfur crude oil and the high-acid crude oil respectively; (2) mixing the pre-treated high-sulfur crude oil and the pre-treated high-acid crude oil obtained in step (1), mixing the mixture with an alkali metal, and then entering an alkali metal treatment reaction zone for reaction; and (3) post-treating the reaction effluent obtained in step (2) to obtain a final product. The method processes the high-sulfur crude oil and the high-acid crude oil together, providing high-quality low-sulfur and low-acid raw materials for subsequent processing.

Description

Technical Field

[0001] The invention belongs to the field of oil refining and chemical industry, and in particular relates to a mixed processing method of high-sulfur crude oil and high-acid crude oil. Background Art

[0002] With the continued rapid development of my country's national economy, energy demand is increasing, placing higher demands on the petrochemical industry. my country imports a large amount of crude oil from the global oil market annually, the majority of which is sour crude oil from the Middle East, characterized by high sulfur content and heavy metal nickel and vanadium content. For example, Saudi heavy crude oil has a sulfur content of over 3.39 wt.%, while extra-heavy crude oil produced in the Orinoco region has a sulfur content of 3.5 to 4.5 wt.%. These characteristics of high-sulfur crude oil lead to problems such as equipment corrosion, catalyst poisoning, and environmental pollution during processing, making it one of the most difficult crude oils to process.

[0003] At present, oil refining enterprises usually carry out desulfurization treatment after fractionation of crude oil in a vacuum distillation unit. The most commonly used desulfurization treatment technology is hydrodesulfurization, which has the following disadvantages: first, the investment and operation cost of the hydrogenation unit is high; second, the catalyst pores are easily clogged by metal impurities, making it difficult to ensure long-term operation. If some sulfides in the crude oil are removed in advance before atmospheric and vacuum distillation, costs will be saved, and the economic and environmental benefits will be very considerable. In view of this, crude oil desulfurization has become a popular research direction. CN107057755A discloses a pre-hydrodesulfurization process for sulfur-containing / high-sulfur crude oil, which belongs to the field of oil processing and petrochemical technology. A pre-hydrodesulfurization process for sulfur-containing / high-sulfur crude oil of the present invention desulfurizes the crude oil by adding a pre-hydrodesulfurization reaction unit before the primary distillation tower. However, this patent still uses hydrotreatment technology for desulfurization, and fails to fundamentally solve the technical problem.

[0004] Another type of crude oil that is difficult for domestic refineries to process is high-acidity crude. For example, crude oil from northern Xinjiang has an acidity of 4.5 mgKOH / g, crude oil from Bohai Sea has an acidity of 3.61 mgKOH / g, and crude oil from Liaohe River has an acidity of 2.69 mgKOH / g. Processing these high-acidity crudes also leads to serious equipment corrosion.

[0005] CN114106874A discloses a method and apparatus for thermal deacidification of high-acid crude oil or high-acid residual oil. The method comprises the following steps: feeding heated raw materials into a gas-liquid separator to separate water and light gas oil; the raw materials separated from water and light gas oil flow out from the bottom of the gas-liquid separator, enter the bottom of a shallow thermal cracking reaction tower, and then flow out from the top; after rapid cooling, a shallow thermal cracking product, i.e., a deacidified product, is obtained. The technical solution of the present invention employs a shallow thermal cracking process using high-acid crude oil or high-acid residual oil as the raw material, preferably under reaction conditions of 370°C to 450°C, a residence time of 20 minutes to 200 minutes, and a reaction pressure of atmospheric pressure to 1.0 MPa. The viscosity of the shallow thermal cracking product is reduced, and the acid value is significantly lowered, by more than 90%. The deacidified product meets the acid value requirements for fuel oil products, or can be used as a raw material for subsequent processing to reduce naphthenic acid corrosion of equipment. However, this method cannot completely avoid the corrosive temperature range of cyclohexane acid, and there are also problems such as excessive cracking of light components and low yield of liquid products.

[0006] In summary, the processing of high-sulfur and high-acid crude oils presents numerous challenges. Consequently, researchers are continuously exploring new desulfurization and deacidification technologies. Among these, alkali metal treatment technology has attracted widespread attention due to its advantages, including low reaction severity, high desulfurization and deacidification selectivity, and energy conservation and environmental protection. Summary of the Invention

[0007] Through in-depth research, the inventors found that alkali metal desulfurization technology has problems such as easy coking and low liquid yield when processing high-sulfur raw materials. The reasons are as follows: Under high temperature conditions, the sulfur-containing compounds in the residual oil react with alkali metals to form intermediate species bonded by alkali metals and organic matter. The above intermediate species are prone to condensation reactions and eventually form coke; the higher the concentration of the above intermediate products in the reaction system, the faster the rate of condensation and coking reaction. One way to solve the above problem is to introduce a certain component into the reaction system, which competes with the sulfur-containing compounds for alkali metals, forming a competitive reaction, thereby adjusting the conversion rate of the sulfur-containing compounds in the reactor, and then controlling the concentration of intermediate species in the reaction system and reducing the occurrence of side reactions such as coking. High-acid crude oil is rich in petroleum acid components such as cyclohexane acid, which can meet the above requirements.

[0008] In response to the shortcomings of the prior art, the present invention provides a method for processing high-sulfur crude oil and high-acid crude oil in a mixed manner. The method processes high-sulfur crude oil and high-acid crude oil together to provide high-quality low-sulfur and low-acid raw materials for subsequent processing.

[0009] A method for mixing high-sulfur crude oil and high-acid crude oil, the method comprising the following steps:

[0010] (1) Pre-treating high-sulfur crude oil and high-acid crude oil separately;

[0011] (2) The pretreated high-sulfur crude oil and the pretreated high-acid crude oil obtained in step (1) are mixed, mixed with an alkali metal, and then enter an alkali metal treatment reaction zone for reaction;

[0012] (3) The reaction effluent obtained in step (2) is post-treated to obtain the final product.

[0013] In the above method, the sulfur content of the high-sulfur crude oil in step (1) is 2.0 to 6.0 wt%, preferably 3.0 to 5.5 wt%, and more preferably 3.5 to 5.0 wt%.

[0014] In the above method, the total acid value of the high-acid crude oil in step (1) is 2.0 to 20.0 mgKOH / g, preferably 5.0 to 12.0 mgKOH / g; the molar ratio of the sulfur content of the high-acid crude oil to the sulfur content of the high-sulfur crude oil is less than 0.3, preferably less than 0.2.

[0015] In the above method, the properties of the high sulfur crude oil and high acid crude oil in step (1) are as follows: density (20°C) is 0.75-1.05 g / cm 3 , preferably 0.85~1.0g / cm 3 ; Metal content 10 ~ 350μg / g, preferably 50 ~ 250μg / g; chemical elements include C, H, S, N, O and metal elements, the C content is generally 83 ~ 87wt.%, H content is generally 11 ~ 14wt.%.

[0016] In the above method, the pretreatment in step (1) includes desalination and dehydration treatment; the present invention has no limitation on the method of desalination and dehydration treatment, and any desalination and dehydration treatment technology that can be implemented in the prior art can be adopted, such as thermal demulsification, chemical demulsification, electrical desalination and dehydration, ultrasonic demulsification, microwave demulsification, membrane demulsification, cyclone separation and freeze-thaw demulsification. One or more of them can be adopted.

[0017] In the above method, the water content of the pretreated high-sulfur crude oil and the pretreated high-acid crude oil obtained in step (1) is less than 0.08 wt.%, preferably less than 0.04 wt.%; and the salt content is less than 8 mg / L, preferably 4 mg / L.

[0018] In the above method, the mass ratio of the pretreated high-sulfur crude oil to the pretreated high-acid crude oil in step (2) is (1-15):1, preferably (3-12):1, and more preferably (5-10):1.

[0019] In the above method, the alkali metal in step (2) is at least one of lithium, sodium, potassium, rubidium, cesium and francium, preferably sodium and / or potassium, and more preferably sodium.

[0020] In the above method, the molar ratio of the alkali metal to the total sulfur content of the raw material in step (2) is (2.0-4.5):1, preferably (2.5-3.5):1; the total sulfur content of the raw material is the sum of the sulfur content of the high-sulfur crude oil and the sulfur content of the high-acid crude oil.

[0021] In the above method, the specific process flow of the alkali metal treatment reaction zone in step (2) is as follows:

[0022] S1, fractionating the pretreated high-acid crude oil to obtain light high-acid crude oil and heavy high-acid crude oil;

[0023] S2, the pretreated high-sulfur crude oil and the light high-acid crude oil obtained in step S1 are mixed, mixed with alkali metal, and then enter the first alkali metal treatment reactor for reaction;

[0024] S3. The reaction effluent obtained in step S2 is mixed with the heavy high-acid crude oil obtained in step S1, and then mixed with alkali metal and enters the second alkali metal treatment reactor for reaction.

[0025] Furthermore, the cutting point in step S1 is 450-540°C, preferably 480-520°C.

[0026] Furthermore, based on the alkali metal alone, the molar ratio of the amount of alkali metal added in step S2 to the amount of alkali metal added in step S3 is (0.5-2.5):1, preferably (1.0-2.0):1.

[0027] Furthermore, the operating conditions of the first alkali metal treatment reactor in step S2 are: reaction temperature 250-370°C, hydrogen partial pressure 1.5-15.0 MPa, reaction time or residence time 0.1-3.0 h, hydrogen to oil volume ratio 300-1800 Nm 3 / m 3 Preferred: reaction temperature 280 ~ 330 ℃, hydrogen partial pressure 3.0 ~ 10.0MPa, reaction time or residence time 0.3 ~ 1.5h, hydrogen oil volume ratio 500 ~ 1000Nm 3 / m 3 .

[0028] Furthermore, the operating conditions of the second alkali metal treatment reactor in step S3 are as follows: compared with the first alkali metal treatment reactor, the reaction temperature is 5 to 50 ° C higher, the hydrogen partial pressure is 1.0 to 5.0 MPa higher, the reaction time or residence time is 0.2 to 1.0 h longer, and the hydrogen-to-oil volume ratio is 100 to 500 Nm higher. 3 / m 3 The preferred operating conditions are: reaction temperature 10-25°C higher, hydrogen partial pressure 1.0-3.0 MPa higher, reaction time or residence time 0.2-0.5 h longer, hydrogen-to-oil volume ratio 200-350 Nm 3 / m3 .

[0029] In the above method, the specific operation process of the post-treatment in step (3) is as follows: the reaction effluent enters the first separation device for solid-liquid separation to obtain a first liquid phase flow; after the first liquid phase flow is mixed with the auxiliary agent, it enters the second separation device for solid-liquid separation to obtain a second liquid phase flow (final product).

[0030] In the above method, the auxiliary agent in step (3) includes one or more of formic acid, hydrochloric acid, acetic acid, sulfuric acid and phosphoric acid solution.

[0031] In the above method, in step (3), the sulfur content of the second liquid phase stream (final product) is controlled to be less than 0.8 wt%, the acid value is less than 0.5 mgKOH / g, and the solid content is 10 to 65 ppm; preferably, the sulfur content is less than 0.5 wt%, the acid value is less than 0.3 mgKOH / g, and the solid content is 15 to 45 ppm.

[0032] By introducing high-acid crude oil into the reaction system, the present invention causes the petroleum acid to compete with sulfur-containing compounds for alkali metals, resulting in a competitive reaction. This reduces the concentration of intermediate species in the reaction system and reduces the occurrence of side reactions such as coking. The main factors affecting this effect are the concentration of the petroleum acid in the reaction system and its molecular structure.

[0033] Furthermore, the inventors used rapid distillation and slicing to discover the following pattern in the distribution of petroleum acids in high-acid crude oil: On the one hand, the acid value increases with increasing distillate temperature; when the distillate temperature rises to the range of 450-540°C, the acid value decreases slightly. On the other hand, as the distillate becomes heavier, the average molecular weight of the petroleum acids increases, and their structure becomes more complex. The present invention slicing high-acid crude oil at a slicing point of 450-540°C, preferably 480-520°C, yields light high-acid crude oil and heavy high-acid crude oil, which are then fed into first and second alkali metal treatment reactors, respectively. The acid values ​​of the light high-acid crude oil and the heavy high-acid crude oil are similar, and their mass yields are very similar. Therefore, introducing the light high-acid crude oil and the heavy high-acid crude oil into the two reactors, respectively, results in essentially the same petroleum acid concentration. However, the petroleum acids contained in the light high-acid crude oil have a simple molecular structure and minimal steric hindrance, making them readily reactive with alkali metals. This can more effectively reduce the concentration of intermediate species and minimize side reactions such as coke formation. That is to say, whether compared with high-acid crude oil or heavy high-acid crude oil, the introduction of light high-acid crude oil has a better effect.

[0034] In the present invention, high-sulfur crude oil has the highest sulfur content, and when reacted alone, the concentration of intermediate species in the reaction system is the highest. Therefore, light high-acid crude oil is first mixed with high-sulfur crude oil and fed into the first alkali metal treatment reactor for reaction, effectively utilizing its effects. The reaction effluent, with a relatively lower sulfur content, is then mixed with heavy high-acid crude oil and fed into the second alkali metal treatment reactor for reaction. Based on the characteristics of the feeds to the two reactors, the present invention introduces light and heavy high-acid crude oils at different stages of the reaction system, achieving efficient utilization of the high-acid crude oil.

[0035] Compared with the prior art, the advantages of the present invention are:

[0036] 1. The method of the present invention realizes the co-processing of high-sulfur crude oil and high-acid crude oil through alkali metal treatment technology, and can provide high-quality low-sulfur and low-acid raw materials in subsequent processing.

[0037] 2. The present method solves the coking problem of high-sulfur crude oil during alkali metal treatment. High-acid crude oil is rich in petroleum acid components such as naphthenic acid. When introduced into the reaction system, the petroleum acids compete with sulfur-containing compounds for alkali metals, forming a competitive reaction. This modulates the conversion rate of sulfur-containing compounds within the reactor, thereby controlling the concentration of intermediate species in the reaction system and reducing the occurrence of side reactions such as coking.

[0038] 3. The method of the present invention sets up two alkali metal treatment reactors, and according to the properties of the feeds of the two reactors, light and heavy high-acid crude oils are introduced respectively at different stages of the reaction system, thereby achieving efficient utilization of high-acid crude oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Attachment Figure 1 The present invention provides a process flow diagram of a mixed processing method of high-sulfur crude oil and high-acid crude oil.

[0040] Among them, 1 is alkali metal, 2 is high-sulfur crude oil, 3 is high-acid crude oil, 4 and 5 are pretreatment devices, 6 is high-sulfur crude oil after pretreatment, 7 is high-acid crude oil after pretreatment, 8 is alkali metal treatment reactor, 9 is reaction effluent of alkali metal treatment reactor; 10 is the first separation device; 11 is the first liquid phase logistics; 12 is the solid phase logistics; 13 is the purification treatment device; 14 is waste gas; 15 is the effluent of the purification treatment device; 16 is the acidic additive; 17 is the second separation device; 18 is the second liquid phase logistics (final product); 19 is the solid phase logistics.

[0041] Attachment Figure 2 A schematic diagram of the process flow of another method for mixing high-sulfur crude oil and high-acid crude oil provided by the present invention.

[0042] Among them, 1 and 25 are alkali metals, 2 is high-sulfur crude oil, 3 is high-acid crude oil, 4 and 5 are pretreatment devices, 6 is high-sulfur crude oil after pretreatment, 7 is high-acid crude oil after pretreatment, 8 is a distillation tower, 9 is light high-acid crude oil, 10 is heavy high-acid crude oil, 11 is the first alkali metal treatment reactor, 12 is the reaction effluent of the first alkali metal treatment reactor, 13 is the second alkali metal treatment reactor, and 14 is the reaction effluent of the second alkali metal treatment reactor; 15 is the first separation device; 16 is the first liquid phase logistics; 17 is the solid phase logistics; 18 is the purification treatment device; 19 is waste gas; 20 is the effluent of the purification treatment device; 21 is the acidic additive; 22 is the second separation device; 23 is the second liquid phase logistics (final product); and 24 is the solid phase logistics. Implementation Method

[0043] The method provided by the present invention is described below with reference to the accompanying drawings.

[0044] like Figure 1 As shown, high-sulfur crude oil 2 and high-acid crude oil 3 enter pretreatment devices 4 and 5 for pretreatment, respectively, to obtain pretreated high-sulfur crude oil 6 and pretreated high-acid crude oil 7; after the two are mixed, they are mixed with alkali metal 1 and enter alkali metal treatment reactor 8 for reaction; the reaction effluent 9 enters the first separation device 10 for treatment to obtain a first liquid phase stream 11 and a solid phase stream 10; the first liquid phase stream 11 enters the purification treatment device 13, is mixed with the acidic additive 14 for reaction, and the obtained reaction effluent 15 enters the second separation device 17 for treatment to obtain a second liquid phase stream (final product) 18 and a solid phase stream 19.

[0045] like Figure 1 As shown, high-sulfur crude oil 2 and high-acid crude oil 3 enter pretreatment devices 4 and 5 for pretreatment, respectively, to obtain pretreated high-sulfur crude oil 6 and pretreated high-acid crude oil 7; the pretreated high-acid crude oil 7 enters a fractionating tower 8 for cutting to obtain light high-acid crude oil 9 and heavy high-acid crude oil 10; the light high-acid crude oil 9 is mixed with the pretreated high-sulfur crude oil 6, and then mixed with alkali metal 1 to enter the first alkali metal treatment reactor 11 for reaction; the reaction effluent 12 is mixed with the heavy high-acid crude oil 10, and then mixed with alkali metal 25 to enter the second alkali metal treatment reactor 13 for reaction, and the reaction effluent 14 enters the first separation device 15 for treatment to obtain a first liquid phase stream 16 and a solid phase stream 17; the first liquid phase stream 16 enters the purification treatment device 18, is mixed with the acidic additive 21 for reaction, and the obtained reaction effluent 20 enters the second separation device 22 for treatment to obtain a second liquid phase stream (final product) 23 and a solid phase stream 24.

[0046] The following examples will further illustrate the method provided by the present invention, but are not intended to limit the present invention.

[0047] The examples and comparative examples were tested on an alkali metal treatment pilot plant designed independently in the laboratory.

[0048] The raw materials used in the examples and comparative examples are high-sulfur crude oil A and high-acid crude oil B, the properties of which are shown in Table 1.

[0049] Table 1 Properties of high sulfur crude oil A and high acid crude oil B

[0050]

[0051] Example 1

[0052] use Figure 1 The process flow is shown.

[0053] (1) High-sulfur crude oil and high-acid crude oil were pretreated separately. Electrodesalting and dehydration technology was used for pretreatment. The demulsifier used was D203 produced by Fushun Yilong Chemical Co., Ltd., with a dosage of 60 μg / g. The specific operating conditions were as follows: temperature 30°C, electric field strength 2000 V / cm, and electric field residence time 60 min. After pretreatment, the high-sulfur crude oil had a water content of 0.03 wt% and a salt content of 0.9 mg / L; the high-acid crude oil had a water content of 0.02 wt% and a salt content of 1.6 mg / L.

[0054] (2) The pretreated high-sulfur crude oil obtained in step (1) and the pretreated high-acid crude oil are mixed in a mass ratio of 5:1, and then mixed with alkali metal and introduced into an alkali metal treatment reactor for reaction; the alkali metal treatment reactor adopts a stirred tank reactor, and the rotation speed is set to 600 r / min.

[0055] (3) The reaction effluent obtained in step (2) enters a high-speed centrifuge for solid-liquid separation to obtain a first liquid phase stream, the high-speed centrifuge speed is 3000 r / min, and the time is 20 min; the first liquid phase stream is mixed with malonic acid at a volume ratio of 100:1, and then enters a high-speed centrifuge for solid-liquid separation to obtain a second liquid phase stream (final product), the high-speed centrifuge speed is 6000 r / min, and the time is 15 min.

[0056] Example 2

[0057] Steps (1) to (3) are the same as in Example 1.

[0058] Example 3

[0059] use Figure 2 The process flow is shown.

[0060] (1) Same as Example 1;

[0061] (2) The pretreated high-sulfur crude oil is fractionated to obtain light high-sulfur crude oil and heavy high-sulfur crude oil, with a cut point of 480°C. The pretreated high-sulfur crude oil and light high-sulfur crude oil are mixed, mixed with alkali metal, and then introduced into a first alkali metal treatment reactor for reaction. The reaction effluent is mixed with the heavy high-sulfur crude oil, mixed with alkali metal, and then introduced into a second alkali metal treatment reactor for reaction. The mass ratio of the pretreated high-sulfur crude oil to the pretreated high-sulfur crude oil is 7.5:1. The alkali metal treatment reactor is a stirred tank reactor with a rotation speed set at 600 r / min.

[0062] (3) Same as Example 1.

[0063] Example 4

[0064] Steps (1) to (3) are the same as those in Example 3. The difference is that the mass ratio of the pretreated high-sulfur crude oil to the pretreated high-acid crude oil is 10:1.

[0065] Example 5

[0066] Steps (1) to (3) are the same as those in Example 3. The difference is that the pretreated high-acid crude oil is fractionated to obtain light high-acid crude oil and heavy high-acid crude oil, with a cut point of 520°C; and the mass ratio of the pretreated high-sulfur crude oil to the pretreated high-acid crude oil is 10:1.

[0067] Comparative Example 1

[0068] In Comparative Example 1, only high-sulfur crude oil was processed.

[0069] (1) High-sulfur crude oil was pretreated using electro-desalting and dehydration technology. The demulsifier used was D203 produced by Fushun Yilong Chemical Co., Ltd., with a dosage of 60 μg / g. The specific operating conditions were as follows: temperature 30°C, electric field strength 2000 V / cm, and electric field residence time 60 min. The water content of the pretreated high-sulfur crude oil was 0.03 wt% and the salt content was 2 mg / L.

[0070] (2) The pretreated high-sulfur crude oil obtained in step (1) is mixed with alkali metal and enters an alkali metal treatment reactor for reaction; the alkali metal treatment reactor adopts a stirred tank reactor, and the rotation speed is set to 600 r / min.

[0071] (3) Same as step (3) in Example 1.

[0072] Comparative Example 2

[0073] (1) High-sulfur crude oil and high-acid crude oil were pretreated separately. Electrodesalting and dehydration technology was used for pretreatment. The demulsifier used was D203 produced by Fushun Yilong Chemical Co., Ltd., with a dosage of 60 μg / g. The specific operating conditions were as follows: temperature 30°C, electric field strength 2000 V / cm, and electric field residence time 60 min. After pretreatment, the high-sulfur crude oil had a water content of 0.03 wt% and a salt content of 2 mg / L; the high-acid crude oil had a water content of 0.02 wt% and a salt content of 6 mg / L.

[0074] (2) Deacidification of the pretreated high-acid crude oil: S1. The pretreated high-acid crude oil was subjected to three-stage countercurrent extraction with a deacidifying agent, which was a mixture of imidazole and ethanol in a mass ratio of 3:7. The specific operating conditions were as follows: agent-to-oil mass ratio of 0.65, time 10 min, temperature 30 °C, and stirring rate 300 r / min. S2. The deacidified crude oil was obtained by liquid-liquid separation, and the acid value of the deacidified crude oil was 1.12 mgKOH / g.

[0075] (3) The pretreated high-sulfur crude oil obtained in step (1) and the deacidified crude oil obtained in step (2) are mixed, mixed with alkali metal, and then enter the alkali metal treatment reactor for reaction; the alkali metal treatment reactor adopts a stirred tank reactor, and the rotation speed is set to 600 r / min.

[0076] (4) Same as step (3) in Example 1.

[0077] Tables 2 and 3 show the operating conditions and test results for the Examples and Comparative Examples. It can be seen that the sulfur content and acid value of high-sulfur and high-acid crude oils were significantly reduced after alkali metal treatment, effectively alleviating equipment corrosion and other issues during subsequent processing. Furthermore, the introduction of high-acid crude oil can reduce the coking tendency of high-sulfur crude oil and improve liquid phase yield.

[0078] Table 2 Operating conditions of Examples and Comparative Examples

[0079]

[0080] Table 3 Test results of examples and comparative examples

[0081]

Claims

1. A method for mixing high-sulfur crude oil and high-acid crude oil, characterized by: The method includes the following contents: (1) Pre-treating high-sulfur crude oil and high-acid crude oil separately; (2) The pretreated high-sulfur crude oil obtained in step (1) is mixed with the pretreated high-acid crude oil, and then mixed with an alkali metal and introduced into an alkali metal treatment reaction zone for reaction; the pretreated high-acid crude oil is not subjected to deacidification treatment; (3) the reaction effluent obtained in step (2) is post-treated to obtain the final product; The high-sulfur crude oil in step (1) has a sulfur content of 2.0 to 6.0 wt%; The total acid value of the high-acid crude oil in step (1) is 2.0 to 20.0 mgKOH / g; the molar ratio of the sulfur content of the high-acid crude oil to the sulfur content of the high-sulfur crude oil is less than 0.3; The pretreatment in step (1) is desalination and dehydration treatment; the desalination and dehydration treatment is one or more of thermal demulsification, chemical demulsification, electrical desalination and dehydration, ultrasonic demulsification, microwave demulsification, membrane demulsification, cyclone separation and freeze-thaw demulsification; The mass ratio of the pretreated high-sulfur crude oil to the pretreated high-acid crude oil in step (2) is (1-15):

1.

2. The method according to claim 1, wherein: The high-sulfur crude oil in step (1) has a sulfur content of 3.0 to 5.5 wt%.

3. The method according to claim 2, wherein: The high-sulfur crude oil in step (1) has a sulfur content of 3.5 to 5.0 wt%.

4. The method according to claim 1, wherein: The total acid value of the high-acid crude oil in step (1) is 5.0 to 12.0 mgKOH / g; and the molar ratio of the sulfur content of the high-acid crude oil to the sulfur content of the high-sulfur crude oil is less than 0.

2.

5. The method according to claim 1, wherein: The properties of the high sulfur crude oil and high acid crude oil in step (1) are as follows: density at 20°C is 0.75-1.05 g / cm 3 ; Metal content 10~350μg / g; Chemical elements include C, H, S, N, O and metal elements, C content is 83~87wt.%, H content is 11~14wt.%.

6. The method according to claim 5, characterized in that: The properties of the high sulfur crude oil and high acid crude oil in step (1) are as follows: density at 20°C is 0.85-1.0 g / cm 3 ;Metal content 50~250μg / g.

7. The method according to claim 1, wherein: The water content of the pretreated high-sulfur crude oil and the pretreated high-acid crude oil obtained in step (1) is less than 0.08 wt.%; and the salt content is less than 8 mg / L.

8. The method according to claim 7, wherein: The water content of the pretreated high-sulfur crude oil and the pretreated high-acid crude oil obtained in step (1) is less than 0.04 wt.%; and the salt content is less than 4 mg / L.

9. The method according to claim 1, wherein: The mass ratio of the pretreated high-sulfur crude oil to the pretreated high-acid crude oil in step (2) is (3-12):

1.

10. The method according to claim 9, characterized in that: The mass ratio of the pretreated high-sulfur crude oil to the pretreated high-acid crude oil in step (2) is (5-10):

1.

11. The method according to claim 1, wherein: The alkali metal in step (2) is at least one of lithium, sodium, potassium, rubidium, cesium and francium.

12. The method according to claim 11, wherein: The alkali metal in step (2) is sodium and / or potassium.

13. The method according to claim 11, wherein: The alkali metal in step (2) is sodium.

14. The method according to claim 1, wherein: The molar ratio of the alkali metal to the total sulfur content of the raw material in step (2) is (2.0-4.5):1; the total sulfur content of the raw material is the sum of the sulfur content of the high-sulfur crude oil and the sulfur content of the high-acid crude oil.

15. The method according to claim 14, characterized in that: The molar ratio of the alkali metal to the total sulfur content of the raw material in step (2) is (2.5-3.5):

1.

16. The method according to claim 1, wherein: The specific process flow of the alkali metal treatment reaction zone in step (2) is as follows: S1, fractionating the pretreated high-acid crude oil to obtain light high-acid crude oil and heavy high-acid crude oil; S2, the pretreated high-sulfur crude oil and the light high-acid crude oil obtained in step S1 are mixed, mixed with alkali metal, and then enter the first alkali metal treatment reactor for reaction; S3. The reaction effluent obtained in step S2 is mixed with the heavy high-acid crude oil obtained in step S1, and then mixed with alkali metal and enters the second alkali metal treatment reactor for reaction.

17. The method according to claim 16, wherein: The cutting point in step S1 is 450-540°C.

18. The method according to claim 17, wherein: The cutting point in step S1 is 480-520°C.

19. The method according to claim 16, wherein: Calculated as a single alkali metal, the molar ratio of the amount of alkali metal added in step S2 to the amount of alkali metal added in step S3 is (0.5-2.5):

1.

20. The method according to claim 19, wherein: Calculated as a single alkali metal, the molar ratio of the amount of alkali metal added in step S2 to the amount of alkali metal added in step S3 is (1.0-2.0):

1.

21. The method according to claim 16, wherein: The operating conditions of the first alkali metal treatment reactor in step S2 are: reaction temperature 250-370°C, hydrogen partial pressure 1.5-15.0 MPa, reaction time or residence time 0.1-3.0 h, hydrogen to oil volume ratio 300-1800 Nm 3 / m 3 .

22. The method according to claim 21, characterized in that: The operating conditions of the first alkali metal treatment reactor in step S2 are: reaction temperature 280-330°C, hydrogen partial pressure 3.0-10.0 MPa, reaction time or residence time 0.3-1.5 h, hydrogen to oil volume ratio 500-1000 Nm 3 / m 3 .

23. The method according to claim 16, wherein: The operating conditions of the second alkali metal treatment reactor in step S3 are as follows: compared with the first alkali metal treatment reactor, the reaction temperature is 5-50°C higher, the hydrogen partial pressure is 1.0-5.0 MPa higher, the reaction time or residence time is 0.2-1.0 h longer, and the hydrogen-to-oil volume ratio is 100-500 Nm higher. 3 / m 3 .

24. The method according to claim 23, wherein: The operating conditions of the second alkali metal treatment reactor in step S3 are as follows: compared with the first alkali metal treatment reactor, the reaction temperature is 10-25°C higher, the hydrogen partial pressure is 1.0-3.0 MPa higher, the reaction time or residence time is 0.2-0.5 h longer, and the hydrogen-to-oil volume ratio is 200-350 Nm higher. 3 / m 3 .

25. The method according to claim 1, wherein: The specific operation process of the post-treatment in step (3) is as follows: the reaction effluent enters the first separation device for solid-liquid separation to obtain a first liquid phase flow; after the first liquid phase flow is mixed with the auxiliary agent, it enters the second separation device for solid-liquid separation to obtain a second liquid phase flow, which is the final product.

26. The method according to claim 25, characterized in that: The auxiliary agent in step (3) includes one or more of formic acid, hydrochloric acid, acetic acid, sulfuric acid and phosphoric acid solution.

27. The method according to claim 25, characterized in that: In step (3), the second liquid phase logistics is controlled so that the sulfur content of the final product is less than 0.8 wt%, the acid value is less than 0.5 mgKOH / g, and the solid content is 10 to 65 ppm.

28. The method according to claim 27, wherein: In step (3), the second liquid phase logistics is controlled so that the sulfur content of the final product is less than 0.5 wt%, the acid value is less than 0.3 mgKOH / g, and the solid content is 15 to 45 ppm.

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