A process for producing a low sulfur low mercaptan gasoline

Abstract

The application discloses a method for producing low-sulfur and low-sulfmercaptan gasoline, and the method comprises the following steps: sequentially feeding a gasoline raw material into a hydrofining reaction zone and an alkali metal treatment reaction zone, and obtaining a clean gasoline product through separation of materials obtained after reaction; and controlling the sulfmercaptan sulfur content of the hydrofining reaction zone reaction effluent to be 20-60 μg / g, and preferably 30-50 μg / g. The method organically combines hydrofining and alkali metal treatment technologies, and can directly produce clean gasoline with low sulfur and low sulfmercaptan by using high-sulfur gasoline raw materials.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of petroleum chemical industry, and relates to a method for producing low-sulfur and low-sulfur gasoline, in particular to a method for producing low-sulfur and low-sulfur gasoline from catalytic cracking gasoline. BACKGROUND

[0002] With the increasingly stringent environmental protection requirements, higher requirements for the quality of vehicle fuels are put forward in the world. Sulfur content is the most critical environmental protection index in vehicle gasoline. In order to further reduce the emission of automobile pollutants, the national standard of the fifth stage of China was implemented nationwide on January 1, 2018, and the sulfur content index limit was reduced from 50 ppm in the fourth stage to 10 ppm, which was reduced by 80%.

[0003] At present, catalytic cracking gasoline is the main blending component of domestic commercial gasoline, accounting for about 70-80wt% of the total amount of gasoline pool. The sulfur content of catalytic cracking gasoline is relatively high, and more than 90wt% of the sulfur in gasoline products comes from catalytic cracking gasoline. As can be seen from the above, reducing the sulfur content of catalytic cracking gasoline is the key to producing clean gasoline. An effective way to solve the above problem is to carry out hydrofining desulfurization on catalytic cracking gasoline. In the process of catalytic cracking gasoline hydrodesulfurization treatment, in order to inhibit the saturation of olefins and avoid the loss of octane number, mild reaction conditions such as low temperature and medium pressure are usually adopted. However, under mild reaction conditions, olefins and hydrogen sulfide are more likely to react to form macromolecular mercaptans, especially when producing low-sulfur gasoline, the reaction of olefins and hydrogen sulfide to form mercaptans under selective hydrogenation process conditions is even close to equilibrium. Therefore, solving the problem of excessive mercaptans after gasoline hydrofining has become the key to producing ultra-low sulfur gasoline.

[0004] CN101619234A discloses a method for producing low-sulfur gasoline from light gasoline, which can produce high-quality clean gasoline with a sulfur content of less than 10μg / g. The process adopts two-stage hydrogenation technology: the first stage uses a selective hydrodesulfurization catalyst to selectively hydrodesulfurize the gasoline raw material, and the reaction product enters the second stage reactor to contact with a hydrodesulfurization catalyst, and the clean gasoline product is obtained after reaction. The selective hydrodesulfurization catalyst used contains alumina as the carrier, molybdenum and cobalt as the active components, and potassium and phosphorus as the additives. The hydrodesulfurization catalyst used contains copper and zinc as the main components.

[0005] CN102757818A discloses a method for producing sulfur-free gasoline, wherein full-range gasoline is first fractionated into light gasoline fraction and heavy gasoline fraction; the light gasoline is subjected to mercaptan removal in an alkali extraction unit and then enters a product tank; the heavy gasoline fraction is subjected to diene removal in a first reaction zone and then subjected to selective hydrodesulfurization in a second reaction zone. The liquid phase stream separated from the second reactor outlet material is subjected to hydrodesulfurization in a third reaction zone, and the liquid phase stream separated from the third reactor effluent is subjected to fractionation and then enters the product tank. The light gasoline fraction and the heavy gasoline fraction in the product tank are mixed to obtain full-range gasoline product.

[0006] The above-mentioned method has the following problems: first, the hydrogenation technology undertakes all the desulfurization functions, however, the deep hydrodesulfurization process needs to further improve the reaction severity, which will cause the increase of olefin saturation rate and the increase of octane loss; second, the macromolecular mercaptan generated by the reaction between olefin and hydrogen sulfide is difficult to remove, and if the hydrogenation method is used, on the one hand, the energy consumption will increase and the cost will rise, on the other hand, the cyclic hydrogenation will further increase the olefin saturation degree, which will cause the octane loss. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application provides a method for producing low-sulfur and low-mercaptan gasoline. The method combines the hydrogenation refining and alkali treatment technologies, and can directly produce clean gasoline with low sulfur and low mercaptan from high-sulfur gasoline raw material.

[0008] A method for producing low-sulfur and low-mercaptan gasoline, the method comprising the following contents: the gasoline raw material is sequentially subjected to reaction in a hydrogenation refining reaction zone and an alkali treatment reaction zone, and the obtained material is separated to obtain clean gasoline product; the mercaptan sulfur content of the hydrogenation refining reaction zone reaction effluent is controlled to be 20-60 μg / g, preferably 30-50 μg / g.

[0009] In the above-mentioned method for producing low-sulfur and low-mercaptan gasoline, the total sulfur content of the hydrogenation refining reaction zone reaction effluent is controlled to be 30-120 μg / g, preferably 40-80 μg / g.

[0010] A specific method for producing low-sulfur and low-mercaptan gasoline, the method comprising the following steps:

[0011] (1) the gasoline raw material is subjected to fractionation to obtain light gasoline fraction and heavy gasoline fraction;

[0012] (2) the heavy gasoline fraction obtained in step (1) is subjected to reaction in a hydrogenation refining reaction zone in the presence of hydrogen to obtain reaction effluent by contacting with a hydrogenation refining catalyst;

[0013] (3) The reaction effluent obtained in step (2) and the light gasoline fraction obtained in step (1) are mixed with an alkali metal and fed into an alkali metal treatment reaction zone for reaction;

[0014] (4) The reaction effluent obtained in step (3) is fed into a separation and purification zone to obtain a clean gasoline product.

[0015] In the above method for producing low-sulfur and low-thiol gasoline, the gasoline feedstock in step (1) is catalytically cracked gasoline; the total sulfur content of the gasoline feedstock is 50-1500 μg / g, the thiol sulfur content is 20-200 μg / g, and the olefin volume fraction is 5-60%.

[0016] In the above method for producing low-sulfur and low-thiol gasoline, the cutting point of the light gasoline fraction and the heavy gasoline fraction in step (1) is 60-120°C, preferably 80-100°C.

[0017] In the above method for producing low-sulfur and low-thiol gasoline, the thiol sulfur content of the light gasoline fraction in step (1) is controlled to be 100-250 μg / g; the thiol sulfur content of the material less than C4 is controlled to be 80-200 μg / g.

[0018] In the above method for producing low-sulfur and low-thiol gasoline, the hydrofining reaction zone in step (2) is provided with 1-3 hydrofining reactors, which can use one or several of fixed bed reactor, moving bed and fluidized bed reactor, preferably fixed bed reactor.

[0019] In the above method for producing low-sulfur and low-thiol gasoline, the hydrofining reaction zone in step (2) generally includes 1-4, preferably 2-3 hydrofining catalyst beds along the liquid phase flow direction.

[0020] In the above method for producing low-sulfur and low-thiol gasoline, the hydrofining catalyst in step (2) includes a carrier and active metals; the carrier is alumina and / or amorphous silica-alumina; the active metals include main active metals and auxiliary metals, the main active metals are Group ⅥB metals in the Periodic Table, such as W and / or Mo; the auxiliary metals are Group Ⅷ metals in the Periodic Table, such as Co and / or Ni. The hydrofining catalyst can be prepared according to the common knowledge in the art, or a commercial catalyst can be selected, such as the commercial catalysts with trade names of RGO-3 and RSDS series produced by Sinopec Catalyst Co., Ltd. Changling Branch.

[0021] In the above method for producing low-sulfur and low-thiol gasoline, the operating conditions of the hydrofining reaction zone in step (2) are as follows: reaction temperature 160-360°C, reaction pressure 1.0-5.0 MPa, volume space velocity 2.0-10.0 h -1 , hydrogen / oil volume ratio 200-1000 Nm 3 / m 3 .

[0022] In the above method for producing low-sulfur and low-sulfur mercaptan gasoline, the alkali metal in step (3) is one or more of lithium, sodium and potassium, preferably sodium; the molar ratio of the alkali metal to the total sulfur content of the feed is (2.0-3.5):1, and the total sulfur content of the feed is the total sulfur content of the mixture of the reaction effluent obtained in step (2) and the light gasoline fraction obtained in step (1).

[0023] In the above method for producing low-sulfur and low-sulfur mercaptan gasoline, the alkali metal treatment reaction zone in step (3) is provided with 1-3 alkali metal treatment reactors; the alkali metal treatment reactors can be any of the reactors capable of realizing liquid-liquid two-phase mixing in the prior art, such as a tubular reactor and / or an autoclave reactor.

[0024] In the above method for producing low-sulfur and low-sulfur mercaptan gasoline, the operating conditions of the alkali metal treatment reaction zone in step (3) are as follows: reaction temperature 250-380℃, reaction pressure 1.0-18.0 MPa, reaction time / residence time 0.1-1.0 h, hydrogen / oil volume ratio 300-1800 Nm 3 / m 3 .

[0025] In the above method for producing low-sulfur and low-sulfur mercaptan gasoline, the separation and purification zone in step (4) includes a desolidification separation zone and an extraction separation zone.

[0026] In the above method for producing low-sulfur and low-sulfur mercaptan gasoline, the specific process flow of the separation and purification zone in step (4) is as follows:

[0027] (a) The reaction effluent obtained in step (3) enters the desolidification separation zone to obtain a desolidified stream;

[0028] (b) The desolidified stream obtained in step (a) enters the extraction separation zone, and after being mixed and contacted with an extractant, clean gasoline product is obtained through separation.

[0029] In the above step (a), the desolidification separation zone is a solid-liquid separation, and there is no limitation on the means of solid-liquid separation, which can be any of the means capable of realizing solid-liquid separation in the prior art, such as one or more of sedimentation, filtration, membrane filtration, pressure filtration and centrifugation.

[0030] In the above step (b), the extractant is selected from one or more of ethanol, furfural, diethylene glycol, dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF); and the extractant / oil volume ratio of the desolidified stream is 0.5-1.0.

[0031] In the step (b) above, the extraction separation zone adopts a liquid-liquid extraction means, which is a unit operation for removing alkali metal mercaptide and other impurities by using different solubilities of components in the desolidification stream in the extractant. The liquid-liquid extraction means includes one or more of single-stage extraction, multi-stage cross-flow extraction, multi-stage countercurrent extraction and continuous countercurrent extraction.

[0032] Compared with the prior art, the present application has the following advantages:

[0033] 1. The method of the present application organically combines hydrofining and alkali metal treatment technologies, and can directly produce clean gasoline with low sulfur and low mercaptan from high-sulfur gasoline.

[0034] 2. The method of the present application transfers difficult-to-remove sulfur compounds such as dibenzothiophene sulfides, heavy olefins and secondary mercaptans generated by the reaction of hydrogen sulfide to the alkali metal treatment reaction zone for processing by controlling the mercaptan sulfur content and total sulfur content of the reaction effluent of the hydrofining reaction zone. Further, the method of the present application reduces the requirements for the reaction effluent of the hydrofining reaction zone, thereby further reducing the reaction severity of the hydrofining reaction zone and reducing the saturation degree of olefins and the loss of octane value.

[0035] 3. The method of the present application cuts the gasoline feedstock into a light gasoline fraction and a heavy gasoline fraction, and the light gasoline fraction is mixed into the feed of the alkali metal treatment reaction zone. The light gasoline fraction is rich in small-molecule mercaptans, which have high activity and can be used as initiators, thereby accelerating the reaction rate and promoting the reaction. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is a process flow diagram of another method for producing low-sulfur and low-mercaptan gasoline according to the present application.

[0037] In the figure, 1 is a gasoline feedstock, 2 is a hydrofining reactor, 3 is a reaction effluent of the hydrofining reactor, 4 is an alkali metal, 5 is an alkali metal treatment reactor, 6 is a reaction effluent of the alkali metal treatment reactor, 7 is a gas-liquid separator, 8 is a solid-liquid two-phase stream, 9 is a hydrogen-containing gas, 10 is a hydrogen compressor, 11 is high-pressure hydrogen, 12 is a solid-liquid separator, 13 is a solid-phase stream, 14 is a liquid-phase stream, 15 is an extractant, 16 is an extraction reactor, 17 is a raffinate phase, 18 is a clean gasoline product, and 19 is fresh hydrogen.

[0038] Figure 2 It is a process flow diagram of another method for producing low-sulfur and low-mercaptan gasoline according to the present application.

[0039] Among them, 1 is gasoline feedstock, 2 is hydrorefining reactor, 3 is hydrorefining reactor effluent, 4 is alkali metal, 5 is alkali metal treatment reactor, 6 is alkali metal treatment reactor effluent, 7 is gas-liquid separator, 8 is solid-liquid two-phase stream, 9 is hydrogen-containing gas, 10 is hydrogen compressor, 11 is high-pressure hydrogen, 12 is solid-liquid separator, 13 is solid stream, 14 is liquid stream, 15 is extractant, 16 is extraction reactor, 17 is raffinate, 18 is clean gasoline product, 19 is new hydrogen, 20 is fractionation tower, 21 is light gasoline fraction, and 22 is heavy gasoline fraction. Implementation

[0040] The method provided by the present invention will now be described with reference to the accompanying drawings.

[0041] like Figure 1 As shown, gasoline feedstock 1 is mixed with high-pressure hydrogen 11 and then enters hydrorefining reactor 2 to react with hydrorefining catalyst, yielding reaction effluent 3. Reaction effluent 3 is mixed with alkali metal 4 and enters alkali metal treatment reactor 5 for further reaction. Reaction effluent 6 enters gas-liquid separator 7 for separation, yielding solid-liquid two-phase stream 8 and hydrogen-containing gas 9. Hydrogen-containing gas 9 is mixed with fresh hydrogen 19 and enters hydrogen compressor 10 to obtain high-pressure hydrogen 11. Solid-liquid two-phase stream 8 enters solid-liquid separator 12 for separation, yielding solid stream 13 and liquid stream 14. Liquid stream 14 enters extraction reactor 16 and is extracted countercurrently with extractant 15 to obtain raffinate 17 and clean gasoline product 18.

[0042] like Figure 2 As shown, gasoline feedstock 1 enters fractionation tower 20 and is split to obtain light gasoline fraction 21 and heavy gasoline fraction 22. Heavy gasoline fraction 22 is mixed with high-pressure hydrogen 11 and then enters hydrorefining reactor 2 to react with hydrorefining catalyst, yielding reaction effluent 3. Reaction effluent 3 and light gasoline fraction 21 are mixed with alkali metal 4 and enter alkali metal treatment reactor 5 for reaction. Reaction effluent 6 enters gas-liquid separator 7 and is separated to obtain solid-liquid two-phase stream 8 and hydrogen-containing gas 9. Hydrogen-containing gas 9 is mixed with fresh hydrogen 19 and enters hydrogen compressor 10 to obtain high-pressure hydrogen 11, while solid-liquid two-phase stream 8 enters solid-liquid separator 12 and is separated to obtain solid stream 13 and liquid stream 14. Liquid stream 14 enters extraction reactor 16 and is countercurrently contacted with extractant 15 for extraction to obtain raffinate phase 17 and clean gasoline product 18.

[0043] The following embodiments will further illustrate the method provided by the present invention, but do not limit the present invention.

[0044] Unless specifically stated otherwise, throughout the specification and claims, the term "comprise" or variations such as "comprises" or "comprising" will be understood to imply the inclusion of a stated element or group of elements but not the exclusion of any other element or group of elements.

[0045] In this document, relational terms such as "first," "second," and the like can be used solely to distinguish one entity or action from another, without necessarily implying a relationship or order between such entities or actions. Numerical designations, such as "first," "second," and the like, are used to distinguish between two or more instances of an element, and are not necessarily intended to indicate relative importance or order of use.

[0046] In this document, the terms "first," "second," etc. are used merely as labels, and are not intended to impose numerical or other order unless specifically stated otherwise.

[0047] In this document, all numerical values of parameters (e.g., of quantities or conditions) are to be interpreted in a relative sense unless otherwise explicitly stated to the contrary.

[0048] The gasoline feedstock properties employed in the examples and comparative examples are shown in Table 1.

[0049] Table 1 Gasoline feedstock properties

[0050]

[0051] Example 1

[0052] The process flow shown was employed, as follows: Figure 1

[0053] (1) The gasoline feedstock entered a hydrofining reaction zone, which was provided with one fixed-bed hydrofining reactor. The reactor was packed with commercial RGO-3, RSDS-21 and RSDS-22 hydrofining catalysts produced by Sinopec Catalyst Co., Ltd. Changling Branch, at a packing volume ratio of 30:30:40. The mercaptan sulfur content of the hydrofining reaction zone effluent was 26 μg / g, and the total sulfur content was 48 μg / g.

[0054] ​(2) The reaction effluent of the hydrofining reaction zone is mixed with sodium and enters the alkali metal treatment reaction zone for reaction. The alkali metal treatment reaction zone is provided with one high-pressure kettle type reactor with stirring, and the rotating speed is 800 r / min.

[0055] (3) The reaction effluent of the alkali metal treatment reaction zone is subjected to solid-liquid separation by a high-speed centrifuge, and the rotating speed of the centrifuge is 8000 r / min. The liquid phase stream obtained by the solid-liquid separation enters an extraction reactor and is contacted with ethanol for three-stage countercurrent extraction. The volume ratio of the solvent to the oil is 0.8, the extraction temperature is 35°C, and the extraction time is 15 min. Finally, clean gasoline product is obtained.

[0056] Example 2

[0057] Compared with Example 1, the difference is that:

[0058] (1) The mercaptan sulfur content of the reaction effluent of the hydrofining reaction zone is 25 μg / g, and the total sulfur content is 41 μg / g.

[0059] Example 3

[0060] The process flow shown in FIG. 1 is adopted, and the specific process is as follows: Figure 2

[0061] (1) The gasoline raw material enters a fractionating column to obtain light gasoline fraction and heavy gasoline fraction by fractionation. The cut point is 80°C, the mercaptan sulfur content of the light gasoline fraction is 162 μg / g, and the mercaptan sulfur content of the carbon four is less than 147 μg / g.

[0062] (2) The heavy gasoline fraction obtained in step (1) enters a hydrofining reaction zone. The hydrofining reaction zone is provided with one fixed bed hydrofining reactor. The reactor is filled with commercial hydrofining catalysts with trade names of RGO-3, RSDS-21 and RSDS-22 produced by Changling Branch Company of Sinopec Catalyst Co., Ltd., and the filling volume ratio is 30:30:40. The mercaptan sulfur content of the reaction effluent of the hydrofining reaction zone is 53 μg / g, and the total sulfur content is 112 μg / g.

[0063] (3) The reaction effluent obtained in step (2) and the light gasoline fraction obtained in step (1) are mixed with sodium and enter the alkali metal treatment reaction zone for reaction. The alkali metal treatment reaction zone is provided with one high-pressure kettle type reactor with stirring, and the rotating speed is 800 r / min.

[0064] ​(4) The reaction effluent from the alkali metal treatment reaction zone in step (3) is subjected to solid-liquid separation by a high-speed centrifuge, the centrifuge speed is 8000 r / min; the liquid phase stream obtained by the solid-liquid separation is introduced into the extraction reactor again, and is contacted with dimethyl sulfoxide to perform four-stage countercurrent extraction, the volume ratio of agent to oil is 0.9, the extraction temperature is 40°C, and the extraction time is 15 min, and finally the clean gasoline product is obtained.

[0065] Example 4

[0066] Compared with Example 3, the difference lies in that:

[0067] (1) The cutting point is 100°C, the mercaptan sulfur content of the light gasoline fraction is 136 μg / g, and the mercaptan sulfur content less than C4 is 115 μg / g.

[0068] (2) The mercaptan sulfur content of the hydrogenation refining reaction effluent is 34 μg / g, and the total sulfur content is 67 μg / g.

[0069] Example 5

[0070] Compared with Example 3, the difference lies in that:

[0071] (1) The cutting point is 100°C, the mercaptan sulfur content of the light gasoline fraction is 136 μg / g, and the mercaptan sulfur content less than C4 is 115 μg / g.

[0072] (2) The mercaptan sulfur content of the hydrogenation refining reaction effluent is 34 μg / g, and the total sulfur content is 67 μg / g.

[0073] The reaction conditions and product properties of Examples 1-5 are shown in Tables 2 and 3.

[0074] Table 2 Reaction conditions of Examples 1-5

[0075]

[0076] Table 3 Product properties of Examples 1-5

[0077]

[0078] Comparative Example 1

[0079] The gasoline feedstock enters a hydrofining reaction zone, which is provided with two fixed-bed hydrofining reactors, a first reactor and a second reactor. The first reactor is filled with commercial hydrofining catalysts of RGO-3, RSDS-21 and RSDS-22 produced by Sinopec Catalyst Co., Ltd. Changling Branch, with a volume ratio of 30:30:40. The second reactor is filled with commercial hydrofining catalyst of RSDS-22 produced by Sinopec Catalyst Co., Ltd. Changling Branch. The reaction conditions and product properties are shown in Table 4.

[0080] Table 4 Reaction conditions and product properties of Comparative Example 1

[0081]

Claims

1. A process for producing low sulfur gasoline, characterized by: The method comprises the following steps: (1) a gasoline raw material is fractionated to obtain a light gasoline fraction and a heavy gasoline fraction; the cut point of the light gasoline fraction and the heavy gasoline fraction is 60-120°C; (2) the heavy gasoline fraction obtained in step (1) is introduced into a hydrofining reaction zone, and is reacted with a hydrofining catalyst in the presence of hydrogen to obtain a reaction effluent; the mercaptan sulfur content of the reaction effluent of the hydrofining reaction zone is controlled to be 20-60 μg / g, and the total sulfur content is controlled to be 30-120 μg / g; (3) the reaction effluent obtained in step (2) and the light gasoline fraction obtained in step (1) are mixed with an alkali metal, and are introduced into an alkali metal treatment reaction zone to react; (4) the reaction effluent obtained in step (3) is introduced into a separation and purification zone to obtain a clean gasoline product.

2. The method of claim 1, wherein: The mercaptan sulfur content of the reaction effluent of the hydrofining reaction zone is controlled to be 30-50 μg / g.

3. The method of claim 1, wherein: The total sulfur content of the reaction effluent of the hydrofining reaction zone is controlled to be 40-80 μg / g.

4. The method of claim 1, wherein: The gasoline raw material in step (1) is catalytically cracked gasoline; the total sulfur content of the gasoline raw material is 50-1500 μg / g, the mercaptan sulfur content is 20-200 μg / g, and the olefin volume fraction is 5-60%.

5. The method of claim 1, wherein: The cut point of the light gasoline fraction and the heavy gasoline fraction in step (1) is 80-100°C.

6. The method of claim 1, wherein: The mercaptan sulfur content of the light gasoline fraction in step (1) is controlled to be 100-250 μg / g; the mercaptan sulfur content of less than carbon four is controlled to be 80-200 μg / g.

7. The method of claim 1, wherein: The hydrofining reaction zone in step (2) is provided with 1-3 hydrofining reactors; the hydrofining reactor adopts one or more of a fixed bed reactor, a moving bed and a fluidized bed reactor.

8. The method of claim 7, wherein: The hydrofining reactor adopts a fixed bed reactor.

9. The method of claim 1, wherein: The hydrofining reaction zone in step (2) comprises 1-4 hydrofining catalyst beds along the liquid phase flow direction.

10. The method of claim 9, wherein: The hydrofining reaction zone in step (2) comprises 2-3 hydrofining catalyst beds along the liquid phase flow direction.

11. The method of claim 1, wherein: The operating conditions of the hydrofining reaction zone in step (2) are as follows: reaction temperature 160-360°C, reaction pressure 1.0-5.0 MPa, volume space velocity 2.0-10.0 h -1 , hydrogen / oil volume ratio 200-1000 Nm 3 / m 3 .

12. The method of claim 1, wherein: The alkali metal in step (3) is one or more of lithium, sodium and potassium; the molar ratio of the alkali metal to the total sulfur content of the feed is (2.0-3.5):1; the total sulfur content of the feed is the total sulfur content of the mixture obtained by mixing the reaction effluent obtained in step (2) and the light gasoline fraction obtained in step (1).

13. The method of claim 12, wherein: The alkali metal in step (3) is sodium.

14. The method of claim 1, wherein: The alkali metal treatment reaction zone in step (3) is provided with 1-3 alkali metal treatment reactors; the alkali metal treatment reactor adopts a tubular reactor and / or a kettle reactor.

15. The method of claim 1, wherein: The operating conditions of the alkali metal treatment reaction zone in step (3) are as follows: reaction temperature 250-380°C, reaction pressure 1.0-18.0 MPa, reaction time / residence time 0.1-1.0 h, hydrogen / oil volume ratio 300-1800 Nm 3 / m 3 .

16. The method of claim 1, wherein: The separation and purification zone in step (4) comprises a solid removal separation zone and an extraction separation zone.

17. The method of claim 16, wherein: The specific process flow of the separation and purification zone in step (4) is as follows: (a) the reaction effluent obtained in step (3) is introduced into a solid removal separation zone to obtain a solid removal stream; (b) the solid removal stream obtained in step (a) is introduced into an extraction separation zone, is mixed with an extractant, and is separated to obtain a clean gasoline product. In step (b), the extractant is selected from one or more of ethanol, furfural, diethylene glycol, dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF); and the volume ratio of the extractant to the oil in the de-solids stream is 0.5-1.

0.

18. The method of claim 17, wherein: In step (a), the de-solids separation zone is a solid-liquid separation, which employs one or more of sedimentation, filtration and centrifugation.

19. The method of claim 18, wherein: The de-solids separation zone is a solid-liquid separation, which employs one or more of membrane filtration and pressure filtration.

20. The method of claim 17, wherein: In step (b), the extractive separation zone employs a liquid-liquid extraction means, which includes one or more of single-stage extraction, multi-stage cross-flow extraction, multi-stage counter-current extraction and continuous counter-current extraction.

Images