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

Abstract

The invention discloses a mixed processing method of high-sulfur crude oil and high-acid crude oil. The method comprises the following steps: (1) respectively pretreating the high-sulfur crude oil and the high-acid crude oil; (2) mixing the pretreated high-sulfur crude oil and the pretreated high-acid crude oil obtained in the step (1), mixing with alkali metal, and enabling the mixture to enter an alkali metal treatment reaction zone for reaction; and (3) carrying out post-treatment on the reaction effluent obtained in the step (2) to obtain a final product. According to the method, high-sulfur crude oil and high-acid crude oil are jointly processed, and low-sulfur and low-acid high-quality raw materials are provided for the subsequent processing process.

Description

Technical Field

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

[0002] With the sustained and rapid development of my country's national economy, the demand for energy is increasing, which puts higher requirements on the petrochemical industry. my country imports a large amount of crude oil from the world oil market every year, most of which is sulfur-containing crude oil from the Middle East, characterized by high sulfur content and heavy metal nickel and vanadium content. For example, the sulfur content of Saudi heavy crude oil is above 3.39wt.%, and the sulfur content of extra heavy crude oil produced in the Orinoco region is 3.5wt.% to 4.5wt.%. These characteristics of high-sulfur crude oil cause problems such as equipment corrosion, catalyst poisoning and environmental pollution during the processing process, and it is one of the difficult-to-process crude oils.

[0003] At present, oil refining enterprises usually carry out desulfurization treatment after the crude oil is fractionated in the atmospheric 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 blocked by metal impurities, and it is difficult to ensure long-term operation. If some sulfides in the crude oil are removed in advance before atmospheric 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-hydrogenation desulfurization process for sulfur-containing / high-sulfur crude oil, which belongs to the field of oil processing and petrochemical technology. A pre-hydrogenation desulfurization process for sulfur-containing / high-sulfur crude oil of the present invention desulfurizes the crude oil by adding a pre-hydrogenation desulfurization reaction unit before the primary distillation tower. However, the patent still uses hydroprocessing technology for desulfurization, which fails to fundamentally solve the technical problem.

[0004] There is another type of crude oil that is difficult to process in domestic refineries, which is high-acid crude oil. Taking some crude oil in my country as an example, the acid value of northern Xinjiang crude oil is 4.5mgKOH / g, the acid value of Bohai crude oil is 3.61mgKOH / g, and the acid value of Liaohe crude oil is 2.69mgKOH / g. The processing of the above high-acid crude oil will also bring serious equipment corrosion problems.

[0005] CN114106874A discloses a method and device for thermal deacidification of high-acid crude oil or high-acid residual oil. The method comprises the following steps: inputting the heated raw material into a gas-liquid separation tank to separate water and light gas oil; the raw material separated from water and light gas oil flows out from the bottom of the gas-liquid separation tank and enters the top of the shallow thermal cracking reaction tower from the bottom to flow out, and after rapid cooling, shallow thermal cracking generated oil, i.e., deacidified product, is obtained. By applying the technical scheme of the present invention, a shallow thermal cracking process is adopted, and high-acid crude oil or high-acid residual oil is used as raw material, preferably under the conditions of reaction temperature of 370°C to 450°C, residence time of 20 minutes to 200 minutes, and reaction pressure of normal pressure to 1.0 MPa, the viscosity of the shallow thermal cracking generated oil is reduced, and the acid value is greatly reduced, with a reduction of more than 90%. The deacidified product meets the acid value requirements of fuel oil products, or can be used as a raw material for subsequent processing to reduce the cyclohexane acid corrosion of equipment. However, this method cannot completely avoid the corrosion 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, there are many problems in the processing technology of high-sulfur crude oil and high-acid crude oil. For this reason, researchers are constantly exploring a new desulfurization and deacidification technology. Among them, alkali metal treatment technology has the advantages of low reaction severity, high desulfurization and deacidification selectivity, energy saving and environmental protection, etc., and has received widespread attention. Summary of the invention

[0007] Through in-depth research, the inventors found that the 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 the alkali metal to form intermediate species bonded by the alkali metal 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 the alkali metal, forming a competitive reaction, thereby adjusting the conversion rate of the sulfur-containing compounds in the reactor, and then controlling the concentration of the 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 view of the shortcomings of the prior art, the present invention provides a mixed processing method of high-sulfur crude oil and high-acid crude oil. The method processes high-sulfur crude oil and high-acid crude oil together to provide low-sulfur, low-acid high-quality raw materials for subsequent processing.

[0009] A mixed processing method of high-sulfur crude oil and high-acid crude oil, the method comprising the following contents: (1) Pre-treating high-sulfur crude oil and high-acid crude oil respectively; (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; (3) The reaction effluent obtained in step (2) is post-treated to obtain the final product.

[0010] 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 %.

[0011] In the above method, the total acid value of the high-acid crude oil in step (1) is 2.0-20.0 mgKOH / g, preferably 5.0-12.0 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.

[0012] 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 to 1.0 g / 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.%.

[0013] In the above method, the pretreatment in step (1) includes desalting and dehydrating treatment. The present invention has no limitation on the method of desalting and dehydrating treatment, and any desalting and dehydrating treatment technology that can be implemented in the prior art can be adopted, such as thermal demulsification, chemical demulsification, electrical desalting and dehydration, ultrasonic demulsification, microwave demulsification, membrane demulsification, cyclone separation and freeze-thaw demulsification. One or more of them can be adopted.

[0014] 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 0.08wt.%, preferably less than 0.04wt.%; and the salt content is less than 8mg / L, preferably 4mg / L.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] In the above method, the specific process flow of the alkali metal treatment reaction zone in step (2) is as follows: S1, the pretreated high-acid crude oil is fractionated 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, and then mixed with alkali metal and 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 into a second alkali metal treatment reactor for reaction.

[0019] Furthermore, the cutting point in step S1 is 450-540°C, preferably 480-520°C.

[0020] 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.

[0021] 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 ° C, 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 .

[0022] Furthermore, in step S3, the operating conditions of the second alkali metal treatment reactor 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 1.0-3.0MPa higher, reaction time or residence time 0.2-0.5h longer, hydrogen-to-oil volume ratio 200-350Nm 3 / m 3 .

[0023] 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).

[0024] 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.

[0025] In the above method, in step (3), the sulfur content of the second liquid phase stream (final product) is controlled to be less than 0.8wt%, the acid value is less than 0.5mgKOH / g, and the solid content is 10-65ppm; preferably, the sulfur content is less than 0.5wt%, the acid value is less than 0.3mgKOH / g, and the solid content is 15-45ppm.

[0026] The present invention introduces high-acid crude oil into the reaction system, so that petroleum acid competes with sulfur-containing compounds for alkali metals, forming a competitive reaction, thereby reducing the concentration of intermediate species in the reaction system and reducing the occurrence of side reactions such as coking. The main factors affecting the above-mentioned effect are the concentration of petroleum acid in the reaction system and the molecular structure of petroleum acid.

[0027] Furthermore, the inventors used rapid distillation cutting methods to find that the distribution of petroleum acid in high-acid crude oil has the following rules: on the one hand, as the fraction temperature increases, the acid value continues to increase; when the fraction temperature rises to the range of 450-540°C, the acid value decreases slightly; on the other hand, as the fraction becomes heavier, the average molecular weight of the petroleum acid continues to increase, and the structure becomes more complex. The present invention cuts the high-acid crude oil, and the cutting point is 450-540°C, preferably 480-520°C, and the obtained light high-acid crude oil and heavy high-acid crude oil enter the first and second alkali metal treatment reactors respectively. The acid values ​​of light high-acid crude oil and heavy high-acid crude oil are not much different, and the mass yield is also very close. Then, light high-acid crude oil and heavy high-acid crude oil are introduced into the two reactors respectively, and the petroleum acid concentration is basically the same. However, the petroleum acid contained in the light high-acid crude oil has a simple molecular structure and a small steric hindrance effect, and is easy to contact with alkali metals for reaction, which can more effectively reduce the concentration of intermediate species and reduce the occurrence of side reactions such as coking. 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.

[0028] In the present invention, the sulfur content of high-sulfur crude oil is the highest, and the concentration of intermediate species in the reaction system is the highest when it reacts alone. Therefore, the light high-acid crude oil is first mixed with the high-sulfur crude oil and enters the first alkali metal treatment reactor for reaction, which can give full play to its role; the sulfur content of the reaction effluent is relatively reduced, and it is mixed with the heavy high-acid crude oil and enters the second alkali metal treatment reactor for reaction. According to the characteristics of the feeds of the two reactors, the present invention introduces light and heavy high-acid crude oils at different stages of the reaction system, thereby realizing efficient utilization of high-acid crude oil.

[0029] Compared with the prior art, the advantages of the present invention are: 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.

[0030] 2. The method of the present invention solves the coking problem of high-sulfur crude oil during the alkali metal treatment process. High-acid crude oil is rich in petroleum acid components such as cyclohexane acid. When high-acid crude oil is introduced into the reaction system, the petroleum acid can compete with sulfur-containing compounds for alkali metals, forming a competitive reaction, thereby adjusting the conversion rate of sulfur-containing compounds in the reactor, and then controlling the concentration of intermediate species in the reaction system, reducing the occurrence of side reactions such as coking.

[0031] 3. The method of the present invention sets up two alkali metal treatment reactors, and introduces light and heavy high-acid crude oils at different stages of the reaction system according to the properties of the feeds of the two reactors, thereby achieving efficient utilization of high-acid crude oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Attached Figure 1 The present invention provides a process flow diagram of a method for mixing high-sulfur crude oil and high-acid crude oil.

[0033] 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.

[0034] Attached 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.

[0035] 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 a first alkali metal treatment reactor, 12 is the reaction effluent of the first alkali metal treatment reactor, 13 is a second alkali metal treatment reactor, 14 is the reaction effluent of the second alkali metal treatment reactor; 15 is a first separation device; 16 is a first liquid phase stream; 17 is a solid phase stream; 18 is a purification treatment device; 19 is waste gas; 20 is the effluent of the purification treatment device; 21 is an acidic additive; 22 is a second separation device; 23 is a second liquid phase stream (final product); 24 is a solid phase stream. Implementation

[0036] The method provided by the present invention is described below in conjunction with the accompanying drawings.

[0037] 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 flow 11 and a solid phase flow 10; the first liquid phase flow 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 flow (final product) 18 and a solid phase flow 19.

[0038] like Figure 1 As shown, the high-sulfur crude oil 2 and the high-acid crude oil 3 enter the pretreatment devices 4 and 5 for pretreatment respectively to obtain the pretreated high-sulfur crude oil 6 and the pretreated high-acid crude oil 7; the pretreated high-acid crude oil 7 enters the fractionation tower 8 for cutting to obtain the light high-acid crude oil 9 and the 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 the 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 the 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 the first liquid phase stream 16 and the 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 the second liquid phase stream (final product) 23 and the solid phase stream 24.

[0039] The following examples will further illustrate the method provided by the present invention, but are not intended to limit the present invention.

[0040] The examples and comparative examples were tested on an alkali metal treatment pilot plant designed independently in the laboratory.

[0041] The raw materials used in the examples and comparative examples are high-sulfur crude oil A and high-acid crude oil B, and their properties are shown in Table 1.

[0042] Table 1 Properties of high sulfur crude oil A and high acid crude oil B

[0043] Example 1 use Figure 1 The process flow is shown.

[0044] (1) Pretreatment of high-sulfur crude oil and high-acid crude oil was performed respectively; the pretreatment adopted electric desalting and dehydration technology, and the demulsifier used was D203 demulsifier produced by Fushun Yilong Chemical Co., Ltd., with a dosage of 60μg / g. The specific operating conditions were as follows: temperature 30℃, electric field strength 2000V / cm, and electric field residence time 60min. The water content of high-sulfur crude oil after pretreatment was 0.03wt%, and the salt content was 0.9mg / L; the water content of high-acid crude oil after pretreatment was 0.02wt%, and the salt content was 1.6mg / L.

[0045] (2) The pretreated high-sulfur crude oil and the pretreated high-acid crude oil obtained in step (1) are mixed in a mass ratio of 5:1, and then mixed with an 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.

[0046] (3) The reaction effluent obtained in step (2) is fed into a high-speed centrifuge for solid-liquid separation to obtain a first liquid phase stream, the speed of the high-speed centrifuge 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 fed into a high-speed centrifuge for solid-liquid separation to obtain a second liquid phase stream (final product), the speed of the high-speed centrifuge is 6000 r / min, and the time is 15 min.

[0047] Example 2 Steps (1) to (3) are the same as those in Example 1.

[0048] Example 3 use Figure 2 The process flow is shown.

[0049] (1) Same as Example 1; (2) 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 480°C; the pretreated high-sulfur crude oil and light high-acid crude oil are mixed, mixed with alkali metal and enter the first alkali metal treatment reactor for reaction; the reaction effluent is mixed with heavy high-acid crude oil, mixed with alkali metal and enter the second alkali metal treatment reactor for reaction. The mass ratio of the pretreated high-sulfur crude oil to the pretreated high-acid crude oil is 7.5:1; the alkali metal treatment reactor adopts a stirred tank reactor, and the speed is set to 600r / min.

[0050] (3) Same as Example 1.

[0051] Example 4 Steps (1) to (3) are the same as those in Example 3, except that the mass ratio of the pretreated high-sulfur crude oil to the pretreated high-acid crude oil is 10:1.

[0052] Example 5 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, and the cut point is 520° C.; the mass ratio of the pretreated high-sulfur crude oil to the pretreated high-acid crude oil is 10:1.

[0053] Comparative Example 1 Comparative Example 1 processes only high-sulfur crude oil.

[0054] (1) Pretreatment of high-sulfur crude oil; the pretreatment adopts electric desalting and dehydration technology, and the demulsifier used is D203 demulsifier produced by Fushun Yilong Chemical Co., Ltd., with a dosage of 60μg / g. The specific operating conditions are as follows: temperature 30℃, electric field strength 2000V / cm, and electric field residence time 60min. The water content of the high-sulfur crude oil after pretreatment is 0.03wt%, and the salt content is 2mg / L.

[0055] (2) The pretreated high-sulfur crude oil obtained in step (1) is mixed with an 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.

[0056] (3) Same as step (3) of Example 1.

[0057] Comparative Example 2 (1) Pretreatment of high-sulfur crude oil and high-acid crude oil was performed respectively; the pretreatment adopted electric desalting and dehydration technology, and the demulsifier used was D203 demulsifier produced by Fushun Yilong Chemical Co., Ltd., with a dosage of 60μg / g. The specific operating conditions were as follows: temperature 30℃, electric field strength 2000V / cm, and electric field residence time 60min. The water content of high-sulfur crude oil after pretreatment was 0.03wt%, and the salt content was 2mg / L; the water content of high-acid crude oil after pretreatment was 0.02wt%, and the salt content was 6mg / L.

[0058] (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, wherein the deacidifying agent was a mixture of imidazole and ethanol, and the mass ratio of the two was 3:7; the specific operating conditions were as follows: agent-oil mass ratio 0.65, time 10 min, temperature 30 °C, 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 (3) The pretreated high-sulfur crude oil obtained in step (1) and the deacidified crude oil obtained in step (2) are mixed, and then mixed with an 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.

[0059] (4) Same as step (3) in Example 1.

[0060] Tables 2 and 3 show the operating conditions and test results of the examples and comparative examples. It can be seen that after being processed by the alkali metal treatment technology, the sulfur content and acid value of high-sulfur crude oil and high-acid crude oil are greatly reduced, which can effectively alleviate the problems of equipment corrosion in the subsequent processing process. Furthermore, the introduction of high-acid crude oil can reduce the coking tendency of high-sulfur crude oil and improve the liquid phase yield.

[0061] Table 2 Operating conditions of the examples and comparative examples

[0062] Table 3 Test results of embodiments and comparative examples

Claims

1. A method for mixing high-sulfur crude oil and high-acid crude oil, characterized in that: The method includes the following contents: (1) Pre-treating high-sulfur crude oil and high-acid crude oil respectively; (2) the pretreated high-sulfur crude oil and the pretreated high-acid crude oil obtained in step (1) are mixed, and then mixed with an alkali metal and introduced into an alkali metal treatment reaction zone for reaction; (3) The reaction effluent obtained in step (2) is post-treated to obtain the final product.

2. The method according to claim 1, characterized in that: 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 %.

3. The method according to claim 1, characterized in that: The total acid value of the high-acid crude oil in step (1) is 2.0-20.0 mgKOH / g, preferably 5.0-12.0 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.

4. The method according to claim 1, characterized in that: 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 to 1.0 g / cm 3 ; Metal content 10 ~ 350μg / g, preferably 50 ~ 250μg / g; chemical elements include C, H, S, N, O and metal elements, C content is 83 ~ 87wt.%, H content is 11 ~ 14wt.%.

5. The method according to claim 1, characterized in that: The pretreatment in step (1) includes 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.

6. The method according to claim 1, characterized in that: The pretreated high-sulfur crude oil and the pretreated high-acid crude oil obtained in step (1) have a water content of less than 0.08 wt.%, preferably less than 0.04 wt.%; and a salt content of less than 8 mg / L, preferably 4 mg / L.

7. The method according to claim 1, characterized in that: In step (2), the mass ratio of the pretreated high-sulfur crude oil to the pretreated high-acid crude oil is (1-15):1, preferably (3-12):1, and more preferably (5-10):

1.

8. The method according to claim 1, characterized in that: 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.

9. The method according to claim 1, characterized in that: 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.

10. The method according to claim 1, characterized in that: The specific process flow of the alkali metal treatment reaction zone in step (2) is as follows: S1, the pretreated high-acid crude oil is fractionated 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, and then mixed with alkali metal and 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 into a second alkali metal treatment reactor for reaction.

11. The method according to claim 10, characterized in that: The cutting point in step S1 is 450-540°C, preferably 480-520°C.

12. The method according to claim 10, characterized in that: Calculated as a single substance of 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, preferably (1.0-2.0):

1.

13. The method according to claim 10, characterized in that: 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 ° C, 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 .

14. The method according to claim 10, characterized in that: 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 The preferred operating conditions are: reaction temperature 10-25°C higher, hydrogen partial pressure 1.0-3.0MPa higher, reaction time or residence time 0.2-0.5h longer, hydrogen-to-oil volume ratio 200-350Nm 3 / m 3 .

15. The method according to claim 1, characterized in that: 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).

16. The method according to claim 15, 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.

17. The method according to claim 15, characterized in that: In step (3), the sulfur content of the second liquid phase stream (final product) is controlled to be less than 0.8wt%, the acid value is less than 0.5mgKOH / g, and the solid content is 10-65ppm; preferably, the sulfur content is less than 0.5wt%, the acid value is less than 0.3mgKOH / g, and the solid content is 15-45ppm.

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