Method for removing organochlorine in crude oil

Abstract

The invention relates to a method for removing organic chlorine in crude oil, which comprises the following steps: carrying out contact reaction on the crude oil, a chlorine transfer agent and water in a reactor for dechlorination, and then carrying out oil-water separation, fibers are contained in the reactor. The method provided by the invention can increase the two-phase mass transfer area and reduce the usage amount of the chlorine transfer agent.

Description

Technical Field

[0001] The invention relates to the field of removing organic chlorine from crude oil, and in particular to a method for removing organic chlorine from crude oil. Background Art

[0002] The chlorine in crude oil is divided into inorganic chlorine and organic chlorine. The two-stage or three-stage electrical desalting process currently used can reduce the content of inorganic chlorine to below 3 mg / L, but the corrosion of chlorine to the equipment of the oil refining unit and the poisoning of the catalyst are still very serious. This is due to the increasing deterioration of crude oil, the large-scale use of chlorine-containing additives in the secondary and tertiary recovery of oil fields, and the gradual increase in the content of organic chlorine in crude oil. However, since electrical desalting is only a physical process, it can only remove inorganic chloride ions. The organic chloride in crude oil is hydrolyzed into chloride ions under the combined action of high temperature and water vapor during the distillation process to generate highly corrosive hydrogen chloride. For the heat exchangers of the low-temperature system of the refining and chemical sector and the reaction distillate of the hydrogen system, there are serious ammonium chloride salting and corrosion problems.

[0003] The phase transfer nucleophilic substitution method is currently widely used for the removal of organic chlorides in crude oil. The principle of this method is that for organic chlorides in crude oil, the phase transfer nucleophilic substitution reaction overcomes the problem that the nucleophilic substitution reaction is difficult to fully contact with the organic chlorides in the oil phase by adding a small amount of phase transfer agent in the dechlorination reaction system, reducing the interfacial tension between oil and water, so that the organic chlorides and nucleophilic reagents can fully contact and react, converting organic chlorides into inorganic chlorine, and enabling the generated inorganic chlorides to be transferred to the water phase. Finally, the organic chlorides in crude oil are removed by oil-water separation, and the dechlorination effect is good.

[0004] Shi Junge et al. (Shi Junge, Wu Mei, Yang Defeng, "Research on the Removal of Organic Chlorides from Crude Oil", Petroleum Refining and Chemical Industry, April 2018, Vol. 49, No. 4, pp. 8-14) conducted experiments and found that the phase transfer agent is preferably tetrabutylammonium hydroxide, the nucleophile is preferably ethylenediamine, and the agent-chlorine ratio n (phase transfer agent): n (nucleophile): n (organic chlorine) is 5:5:1. Most of the organic chlorides in crude oil can be removed, and the dechlorination rate can reach more than 90%. However, the disadvantage of this method is that the phase transfer agent and the organic chlorine in the crude oil are not fully mixed, and the amount used is large.

[0005] In view of the problems existing in the current use of crude oil chlorine transfer agents, there is an urgent need for a more effective method for removing organic chlorine from crude oil that reduces the amount of chlorine transfer agents used. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects of the prior art crude oil chlorine transfer agent that fails to fully play its role and is used in large amounts, and to provide a method for removing organic chlorine from crude oil.

[0007] In order to achieve the above object, the present invention provides a method for removing organic chlorine from crude oil, comprising the following steps: contacting and reacting crude oil, chlorine transfer agent and water in a reactor to dechlorinate, and then separating the oil and water; the reactor contains fibers.

[0008] Specifically, since the reactor is equipped with metal or non-metallic fibers, when crude oil, water and chlorine transfer agent enter from the top of the reactor, due to capillary action, the tension of oil and water on the fiber surface is different, and the affinity of oil and water to the fiber is different. The water phase is easier to spread on the fiber surface, forming a liquid film flowing in the forward direction between the fibers. Due to the different flow rates of the two phases, the friction between the two phases pulls the liquid film very thin, providing a large enough place for two-phase mass transfer. During the mass transfer process, the organic chlorine in the crude oil reacts with the chlorine transfer agent to generate salt compounds that dissolve in the water phase. When the mass transfer is completed, the water phase flows directly to the bottom of the tank along the fiber, while the oil phase with a lighter density floats on top, and the two phases are separated, and the organic chlorine in the crude oil escapes with the water phase.

[0009] As a specific embodiment of the present invention, preferably, the fiber is a metal and / or non-metal fiber; further preferably, the metal fiber is selected from at least one of stainless steel wire and carbon steel wire; and / or the non-metal fiber is at least one of glass fiber, polyamide fiber and polyester fiber. Specifically, the fiber can be various industrial fiber products, such as 310S series stainless steel wire purchased from Tianjin Haobo Metal Materials Co., Ltd., 6 mm glass fiber purchased from Renqiu Senyi Glass Fiber Cloth Factory, Hebei Province, and polyester fiber purchased from Tai'an Quanyou Engineering Materials Co., Ltd., Shandong Province.

[0010] According to the present invention, the mass transfer space cylinder of the fiber membrane reactor can be of a size that can provide the required size for removing organic chlorine and water from crude oil. Preferably, the aspect ratio of the mass transfer space cylinder is 20-60.

[0011] As a specific embodiment of the present invention, preferably, the reactor is a fiber membrane reactor.

[0012] As a specific embodiment of the present invention, preferably, the chlorine transfer agent includes a phase transfer agent, a nucleophile and a solvent. Further preferably, the chlorine transfer agent consists of a phase transfer agent, a nucleophile and a solvent. Even more preferably, the molar ratio of the phase transfer agent, the nucleophile and the solvent is 0.7-1.3:1.3-0.7:2.

[0013] Specifically, when the organic chlorine in the crude oil reacts with the chlorine transfer agent, the organic chlorine in the crude oil and the nucleophilic reagent react under the catalytic action of the phase transfer agent, and the generated salt compound dissolves in the water phase.

[0014] As a specific embodiment of the present invention, preferably, the phase transfer agent is selected from at least one of tetrabutylammonium hydroxide and polyethylene glycol, and more preferably tetrabutylammonium hydroxide; and / or the nucleophilic reagent is selected from at least one of ethylenediamine, triethylamine, and trimethylamine, and more preferably ethylenediamine.

[0015] As a specific embodiment of the present invention, preferably, the solvent is selected from at least one of anhydrous ethanol and methanol, and more preferably anhydrous ethanol.

[0016] As a specific embodiment of the present invention, preferably, the ratio of the amount of the phase transfer agent, the nucleophilic reagent and the organic chlorine in the crude oil is 1:1:1-2:2:1.

[0017] As a specific embodiment of the present invention, preferably, based on the total volume of the metal and / or non-metallic fibers in the reactor, the crude oil feed rate is a volume space velocity of 2-12h -1 ; and / or water is added in an amount of 2-20% by weight of the crude oil, preferably 4-12%.

[0018] As a specific embodiment of the present invention, preferably, the operating temperature of the reactor is 80-140° C., and the working pressure is 0.1-1.0 MPa.

[0019] As a specific embodiment of the present invention, preferably, the following steps are further included: the crude oil obtained after oil-water separation is further desalted and dehydrated; further preferably, the desalting and dehydrating is carried out in an electric desalter.

[0020] The crude oil method for removing organic chlorine provided by the present invention can be used in combination with an existing electric desalting device to remove organic chlorine from mixed crude oil processed by refining enterprises, and can assist chlorine transfer agents to fully exert their effects, thereby significantly reducing the amount of chlorine transfer agents used during crude oil dechlorination. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the method for removing organic chlorine from crude oil according to the present invention, wherein:

[0022] 1-chlorine transfer agent storage tank, 2-chlorine transfer agent delivery pump, 3-chlorine transfer agent heat exchanger, 4-water tank, 5-water delivery pump, 6-water heat exchanger, 7-crude oil storage tank, 8-crude oil delivery pump, 9-crude oil heat exchanger, 10-fiber membrane reactor, 11-sedimentation tank, 12-crude oil, 13-wastewater. DETAILED DESCRIPTION

[0023] The technical scheme of the present invention is further described below by specific embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be obtained commercially.

[0024] The present invention provides a method for removing organic chlorine from crude oil, which comprises: contacting and reacting the crude oil with a chlorine transfer agent in a fiber membrane reactor, and after oil and water are separated, the crude oil enters an electric desalting device for further desalting and dehydration. Figure 1 As shown, the chlorine transfer agent is fed from the chlorine transfer agent storage tank 1 to the chlorine transfer agent heat exchanger 3 through the chlorine transfer agent delivery pump 2, and then enters the fiber membrane reactor 10 after being heated. At the same time, water is fed from the water tank 4 to the water heat exchanger 6 through the water delivery pump 5, and then enters the fiber membrane reactor 10 after being heated. The crude oil is fed from the crude oil storage tank 7 to the crude oil heat exchanger 9 through the crude oil delivery pump 8, and then enters the fiber membrane reactor 10 after being heated. The crude oil, the chlorine transfer agent and the water are contacted and reacted in the fiber membrane reactor, and then enter the settling tank 11 for oil-water separation, and the crude oil and the sewage are respectively output from the settling tank 11, and the crude oil subsequently enters the electric desalting device for further desalting and dehydration.

[0025] The fiber membrane reactor 10 in the present invention is a high-efficiency mass transfer equipment. The fiber membrane reactor can be a cylindrical body with openings at both ends, the two ends being a feed end and a discharge end. There are two feed ports on the feed end, and the discharge end is connected to a subsequent settling tank for oil-water separation. A fluid distributor and a mass transfer space cylinder are sequentially arranged from the feed end to the discharge end in the fiber membrane reactor. A fluid redistributor and fiber filaments are sequentially arranged in the mass transfer space cylinder from the feed end to the discharge end. The fluid distributor and the fluid redistributor can be selected from one of a perforated plate type, an overflow type and a plate type fluid distributor, and there can be more than one set of fluid redistributors. The fluid distributor and the fluid redistributor enable the fluid entering the fiber membrane reactor to be well distributed on the cross section of the fiber filament, thereby making the mass transfer effect of the fluid in the fiber membrane reactor better. The fiber filaments are installed in the mass transfer space cylinder of the fiber membrane reactor. The evenly distributed fluid from the distributor flows through the fiber filaments. By utilizing capillary action and the different surface tensions of the water phase and the oil phase on the fiber filaments, the water phase and the oil phase added to the fiber membrane reactor form a liquid film on the surface of the fiber filaments, thereby increasing the surface area of ​​contact between the two phases and greatly improving the mass transfer efficiency.

[0026] In the present invention, the chlorine transfer agent, crude oil and water enter from the top of the fiber membrane reactor. During the mass transfer process, the organic chlorine in the crude oil and the nucleophilic reagent in the chlorine transfer agent react under the action of the phase transfer catalyst to generate salt compounds that dissolve in the water phase. After the mass transfer is completed, the water phase flows directly to the bottom of the tank along the fiber, while the oil phase with a lighter density floats on the surface, and the two phases are separated, and the organic chlorine in the crude oil is removed with the water phase. Finally, the crude oil and sewage are obtained through oil-water sedimentation separation.

[0027] In a more preferred embodiment, in order to further reduce the organic chlorine content of the crude oil obtained after treatment according to the method of the present invention, so as to obtain a further improved organic chlorine removal effect, the following technologies are combined for implementation: (1) the fibers of the fiber membrane reactor are metal wires or non-metal wires; (2) the aspect ratio of the mass transfer space cylinder of the fiber membrane reactor is 20-60; (3) the molar ratio of various components in the chlorine transfer agent is preferably n (phase transfer agent): n (nucleophile): n (anhydrous ethanol) = 0.7-1.3: 1.3-0.7: 2; (4) the amount of chlorine transfer agent satisfies: the agent-chlorine ratio is n (phase transfer agent): n (nucleophile): n (organic chlorine) = 1: 1: 1-2: 2: 1; (5) the implementation conditions of the fiber membrane reactor include: the feed rate of crude oil is based on the volume of the fiber filaments in the fiber membrane reactor, and the volume space velocity is 2-12h -1 The operating temperature of the fiber membrane reactor is 80-140°C and the working pressure is 0.1-1.0MPa.

[0028] The present invention will be described in detail by way of examples. In the following examples, the salt (inorganic chlorine) content in crude oil is determined by SY / T 0536-2008; the water content in crude oil is determined by GB / T 9168; the total chlorine content in crude oil is determined by microcoulometry; the organic chlorine in crude oil = total chlorine - inorganic chlorine; the dechlorination rate = organic chlorine content in crude oil after removal / organic chlorine content in crude oil * 100%.

[0029] The industry's requirements for crude oil desalting and dehydration are:

[0030] Water content <0.2m%; salt content <3mg / L.

[0031] The crude oil raw material is imported mixed crude oil processed by a refinery. The properties of the two batches of crude oil used are shown in Table 1.

[0032] Table 1

[0033]

[0034] Example 1

[0035] This example is used to illustrate the method for removing organic chlorine from crude oil of the present invention.

[0036] (1) Removal of organic chlorine: Preheat crude oil 1 to 90°C, and preheat the chlorine transfer agent (the phase transfer agent is tetrabutylammonium hydroxide, the nucleophile is ethylenediamine, the solvent is anhydrous ethanol, and the molar ratio of each component is 1:1:2) to 50°C. Inject crude oil 1, chlorine transfer agent and water into the fiber membrane reactor together. Install 310S series stainless steel wire from Tianjin Haobo Metal Materials Co., Ltd. in the mass transfer space cylinder of the fiber membrane reactor. The aspect ratio of the mass transfer space cylinder is 60, and the weight of the installed fiber wire is 5.5kg. The operating conditions of the fiber membrane reactor are: temperature 80°C, pressure 0.1MPa. The crude oil feed rate is a volumetric space velocity of 12h -1 (Based on the total volume of the metal and / or non-metallic fibers in the reactor), the amount of water added is 8m% of the amount of crude oil used, and the agent-chlorine ratio is n (phase transfer agent): n (nucleophile): n (organic chlorine in crude oil) = 1:1:1.

[0037] (2) Oil-water separation: The product discharged from the organic chlorine removal step is allowed to stand in a sedimentation tank for 40 minutes. The settled sewage discharged from the lower outlet is sent to the sewage treatment unit. 7 mg / kg of Nalco-3 oil-soluble demulsifier produced by Nalco (China) Environmental Technology Service Co., Ltd., 0.5 mg / kg of Yueshou-3 water-soluble demulsifier produced by Guangdong Yueshou New Technology Co., Ltd. and 6% water by weight of crude oil are added to the crude oil on the upper layer of the sedimentation tank, heated to 80°C and then mixed in a primary mixer, and placed in a primary electric desalting tank and energized to stand. The operating conditions of the primary electric desalting tank are: standing temperature: 130°C, electric field strength of 1000V / cm, standing time of 30 minutes, and then oil-water separation is performed.

[0038] The crude oil from the primary desalter is added with 5% water of the crude oil dosage, heated to 80°C, and then mixed in the secondary mixer, and then placed in the secondary desalter for energization and standing. The operating conditions are the same as those of the primary desalter.

[0039] The total chlorine, salt and water contents of the crude oil obtained by the fiber membrane reactor and the two-stage electrical desalting were determined. The results are shown in Table 2.

[0040] Example 2

[0041] This example is used to illustrate the method for removing organic chlorine from crude oil of the present invention.

[0042] (1) Removal of organic chlorine: Preheat crude oil 1 to 90°C, and preheat the chlorine transfer agent (the phase transfer agent is tetrabutylammonium hydroxide, the nucleophile is ethylenediamine, the solvent is anhydrous ethanol, and the molar ratio of each component is 1:1:2) to 50°C. Inject crude oil 1, chlorine transfer agent and water into the fiber membrane reactor together. 6 mm glass fiber filaments from Senyi Glass Fiber Cloth Factory, Renqiu City, Hebei Province are installed in the mass transfer space cylinder of the fiber membrane reactor. The aspect ratio of the mass transfer space cylinder is 40, and the weight of the installed fiber filaments is 1.8 kg. The operating conditions of the fiber membrane reactor are: temperature 135°C, pressure 1.0 MPa. The crude oil feed rate is a volumetric space velocity of 2h -1 (Based on the total volume of the metal and / or non-metallic fibers in the reactor), the amount of water added is 8m% of the amount of crude oil used, and the agent-chlorine ratio is n (phase transfer agent): n (nucleophile): n (organic chlorine) = 2:2:1.

[0043] (2) Oil-water separation: This step is the same as in Example 1.

[0044] The total chlorine, salt and water contents of the crude oil obtained by the fiber membrane reactor and the two-stage electrical desalting were determined. The results are shown in Table 2.

[0045] Example 3

[0046] This example is used to illustrate the method for removing organic chlorine from crude oil of the present invention.

[0047] (1) Removal of organic chlorine: Preheat crude oil 1 to 90°C, and preheat the chlorine transfer agent (the phase transfer agent is tetrabutylammonium hydroxide, the nucleophile is ethylenediamine, the solvent is anhydrous ethanol, and the molar ratio of each component is 1:1:2) to 50°C. Inject crude oil 2, chlorine transfer agent and water into the fiber membrane reactor together. Polyester fiber filaments from Shandong Tai'an Quanyou Engineering Materials Co., Ltd. are installed in the mass transfer space cylinder of the fiber membrane reactor. The aspect ratio of the mass transfer space cylinder is 20, and the weight of the installed fiber filaments is 0.9kg. The operating conditions of the fiber membrane reactor are: temperature 110°C, pressure 0.5MPa. The crude oil feed rate is a volumetric space velocity of 7h -1 (Based on the total volume of the metal and / or non-metallic fibers in the reactor), the amount of water added is 8m% of the amount of crude oil used, and the agent-chlorine ratio is n (phase transfer agent): n (nucleophile): n (organic chlorine) = 1.5:1.5:1.

[0048] (2) Oil-water separation: This step is the same as in Example 1.

[0049] The total chlorine, salt and water contents of the crude oil obtained by the fiber membrane reactor and the two-stage electrical desalting were determined. The results are shown in Table 2.

[0050] Example 4

[0051] The method of Example 1 is followed, except that crude oil 2, a chlorine transfer agent (a phase transfer agent is polyethylene glycol, a nucleophile is ethylenediamine, a solvent is anhydrous ethanol, and the molar ratio of each component is 1:1:2), and 8 mg / kg of Nalco-3 oil-soluble demulsifier produced by Nalco (China) Environmental Technology Service Co., Ltd. and 1.0 mg / kg of Yueshou-3 water-soluble demulsifier produced by Guangdong Yueshou New Technology Co., Ltd. are added to the crude oil in the upper layer of the settling tank.

[0052] The total chlorine, salt and water contents of the crude oil obtained by the fiber membrane reactor and the two-stage electrical desalting were determined. The results are shown in Table 2.

[0053] Example 5

[0054] The method of Example 2 is followed, except that crude oil 2, a chlorine transfer agent (a phase transfer agent is polyethylene glycol, a nucleophilic agent is ethylenediamine, a solvent is anhydrous ethanol, and the molar ratio of each component is 1:1:2), and 8 mg / kg of Nalco-3 oil-soluble demulsifier produced by Nalco (China) Environmental Technology Service Co., Ltd. and 1.0 mg / kg of Yueshou-3 water-soluble demulsifier produced by Guangdong Yueshou New Technology Co., Ltd. are added to the crude oil in the upper layer of the settling tank.

[0055] The total chlorine, salt and water contents of the crude oil obtained by the fiber membrane reactor and the two-stage electrical desalting were determined. The results are shown in Table 2.

[0056] Example 6

[0057] The method of Example 2 is followed, except that crude oil 2, a chlorine transfer agent (a phase transfer agent is polyethylene glycol, a nucleophilic agent is ethylenediamine, a solvent is anhydrous ethanol, and the molar ratio of each component is 1:1:2), and 8 mg / kg of Nalco-3 oil-soluble demulsifier produced by Nalco (China) Environmental Technology Service Co., Ltd. and 1.0 mg / kg of Yueshou-3 water-soluble demulsifier produced by Guangdong Yueshou New Technology Co., Ltd. are added to the crude oil in the upper layer of the settling tank.

[0058] The total chlorine, salt and water contents of the crude oil obtained by the fiber membrane reactor and the two-stage electrical desalting were determined. The results are shown in Table 2.

[0059] Comparative Example 1

[0060] The method of Example 1 is followed, except that demetallization is performed by electro-desalting. The reagent-chlorine ratio is n (phase transfer agent): n (nucleophilic agent): n (organic chlorine in crude oil) = 5:5:1.

[0061] After adding 7mg / kg of Nalco-3 oil-soluble demulsifier produced by Nalco (China) Environmental Technology Service Co., Ltd., 0.5mg / kg of Yueshou-3 water-soluble demulsifier produced by Guangdong Yueshou New Technology Co., Ltd. and 6m% of water used for crude oil into crude oil, the crude oil is heated to 80°C and then mixed in a primary mixer, and then placed in a primary electric desalter and energized for standing. The operating conditions of the primary electric desalter are: standing temperature: 130°C, electric field strength of 1000V / cm, standing time of 30 minutes, and then oil-water separation is performed.

[0062] The crude oil from the primary desalter is added with 5% water of the crude oil dosage, heated to 80°C, and then mixed in the secondary mixer, and then placed in the secondary desalter for energization and standing. The operating conditions are the same as those of the primary desalter.

[0063] The crude oil from the secondary electric desalter is added with 4% water of the crude oil dosage, heated to 80°C, and then mixed in the tertiary mixer, and then placed in the tertiary electric desalter for energization and standing. The operating conditions are the same as those of the primary electric desalter.

[0064] The total chlorine, salt and water contents of the crude oil obtained after the three-stage electrical desalting treatment were determined. The results are shown in Table 2.

[0065] Comparative Example 2

[0066] The method of Example 1 is followed, except that no fibers are added into the fiber membrane reactor, which is only used as a simple oil-water separation tank.

[0067] The total chlorine, salt and water contents of the crude oil obtained after the reactor and two-stage electro-desalting treatment were determined. The results are shown in Table 2.

[0068] Table 2

[0069]

[0070] It can be seen from the implementation results of the above embodiments and comparative examples that the method for removing organic chlorine from crude oil provided by the present invention can achieve the effect of removing organic chlorine from crude oil and obtain crude oil raw materials that meet industrial requirements. Specifically, compared with the conventional electrical desalting technology used in Comparative Example 1, Example 1 reduces the use of 1 / 3 of electricity, thereby reducing energy consumption. The agent-chlorine ratio in Example 1 is n (phase transfer agent): n (nucleophilic agent): n (organic chlorine in crude oil) = 1:1:1; while the agent-chlorine ratio in the comparative example is n (phase transfer agent): n (nucleophilic agent): n (organic chlorine in crude oil) = 5:5:1, the latter is 5 times the former. Therefore, Example 1 can save the amount of chemical reagents. In Comparative Example 2, the reactor is not filled with fibers, the contact area between the two phases is not expanded, and the reaction cannot be fully carried out, so the organic chlorine removal rate is low.

[0071] It can be seen that the method provided by the present invention can save electricity consumption, increase the two-phase mass transfer area, and reduce the amount of chemical reagents used.

[0072] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A method for removing organic chlorine from crude oil, characterized in that: The following steps are involved: Crude oil, chlorine transfer agent and water are contacted and reacted in a reactor to dechlorinate, and then the oil and water are separated; the reactor contains fibers.

2. The method according to claim 1, characterized in that The fibers are metal and / or non-metal fibers; preferably, the metal fibers are selected from at least one of stainless steel wire and carbon steel wire; and / or the non-metal fibers are at least one of glass fibers, polyamide fibers and polyester fibers.

3. The method according to claim 1 or 2, characterized in that The reactor is a fiber membrane reactor.

4. The method according to any one of claims 1 to 3, characterized in that The chlorine transfer agent comprises a phase transfer agent, a nucleophile and a solvent. Preferably, the chlorine transfer agent consists of a phase transfer agent, a nucleophile and a solvent. Preferably, the molar ratio of the phase transfer agent, the nucleophile and the solvent is 0.7-1.3:1.3-0.7:

2.

5. The method according to claim 4, characterized in that The phase transfer agent is selected from at least one of tetrabutylammonium hydroxide and polyethylene glycol, preferably tetrabutylammonium hydroxide; and / or the nucleophilic agent is selected from at least one of ethylenediamine, triethylamine and trimethylamine, preferably ethylenediamine.

6. The method according to claim 4 or 5, characterized in that The solvent is selected from at least one of anhydrous ethanol and methanol, preferably anhydrous ethanol.

7. The method according to any one of claims 4 to 6, characterized in that The ratio of the amount of the phase transfer agent, the nucleophilic reagent and the organic chlorine in the crude oil is 1:1:1-2:2:

1.

8. The method according to any one of claims 1 to 7, characterized in that Based on the total volume of the metal and / or non-metallic fibers in the reactor, the crude oil feed rate is a volume space velocity of 2-12 h -1 ; and / or water is added in an amount of 2-20% by weight of the crude oil, preferably 4-12%.

9. The method according to any one of claims 1 to 8, characterized in that The operating temperature of the reactor is 80-140°C and the working pressure is 0.1-1.0 MPa.

10. The method according to any one of claims 1 to 9, characterized in that The following steps are also included: The crude oil obtained after oil-water separation is further desalted and dehydrated; preferably, the desalting and dehydrating is carried out in an electric desalter.

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