A solid acid alkylation reaction process

Abstract

A process for the solid acid alkylation reaction characterized in that an aromatic hydrocarbon and a long chain alkene are contacted in the presence of a solid acid catalyst to perform an alkylation reaction to obtain a linear alkyl aromatic hydrocarbon, the process further comprising: when the conversion of the long chain alkene is ≥ 99%, every 5-36 h, an A step of stopping the feed of the aromatic hydrocarbon and the long chain alkene and flushing the solid acid catalyst with an aromatic hydrocarbon material at 130-350 DEG C, and when the conversion of the long chain alkene is < 99%, a B step of calcining the solid acid catalyst with an oxygen-containing gas at 400-600 DEG C.

Description

Technical Field

[0001] This invention relates to a solid acid alkylation reaction method, and more specifically, to an alkylation reaction method for preparing straight-chain alkyl aromatics using a solid acid as a catalyst and aromatics and long-chain olefins as raw materials. Background Technology

[0002] Linear alkylbenzenes, obtained by alkylation of benzene and long-chain olefins, are an important chemical intermediate in the synthesis of various detergents. This intermediate can be further processed through sulfonation and neutralization to yield alkylbenzene sulfonates, a high-performance anionic surfactant. This reaction, which began in the 1940s, laid the foundation for the synthetic detergent industry.

[0003] Currently, 83% of global linear alkylbenzene production uses the HF process, 9% uses the AlCl3 process, and 8% uses the DEL process. Both the HF and AlCl3 processes have various drawbacks, including high environmental pollution, severe equipment corrosion, difficulty in product separation, and high investment costs.

[0004] The Detal process is a solid acid process jointly developed by UOP (United States Petroleum Corporation) and CEPSA (Spain Petroleum Company), and was industrialized in the mid-1990s. Because the Detal process uses a fluorine-containing amorphous silica-alumina catalyst, it suffers from problems such as fluorine loss, discontinuous alkylation reactions and catalyst regeneration, high operating costs, and frequent regeneration, which to some extent limits its widespread adoption and development.

[0005] Developing green and environmentally friendly solid acid alkylation technology is a future trend. Research institutes such as the Petrochemical Research Institute, East China University of Science and Technology, Nanjing Alkylbenzene Plant, and the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, have all conducted research on the synthesis of straight-chain alkylbenzenes from benzene and long-chain olefins via solid acid catalysis, primarily employing molecular sieves and heteropolyacid-type solid acid catalysts. However, the problems of easy deactivation and short single-pass lifespan of solid acid catalysts have not been effectively solved. Therefore, developing green solid acid catalyst technology that enables long-term stable operation and easy regeneration has significant economic and social benefits.

[0006] To improve the single-cycle lifetime and extend the stable operating time of solid acid catalysts in this reaction, research has largely focused on the synthesis of catalytic materials or process optimization from a process perspective; however, for the regeneration of solid acid catalysts, solvent elution is commonly used. These methods generally suffer from poor reaction performance of the catalytic materials, frequent regeneration process operations, and high costs.

[0007] CN1043524C discloses a method for benzene alkylation using fluorinated silica-alumina and straight-chain monoolefins. Under alkylation conditions, benzene and straight-chain monoolefins are contacted with a fluorinated silica-alumina catalyst comprising silica and alumina in a weight ratio of 1:1 to 9:1 and a fluoride content of 1 to 6 wt%, using C6 to C4 olefins. 20 A linear monoolefin is used to alkylate benzene, achieving 98% olefin conversion, 85% or better selectivity for the monoalkylbenzene, and at least 90% linearity with respect to the monoalkylbenzene produced. However, this method suffers from low olefin conversion and environmental pollution problems due to fluoride ion loss.

[0008] CN101535221A discloses a method for preparing alkylbenzenes on a solid acid catalyst with a low benzene to olefin ratio and low heavy matter formation, wherein small crystals and acidic FAU molecular sieves are used as catalysts.

[0009] CN111514924A discloses a catalytic synthesis method for long-chain alkyl aromatics, the method comprising: first, feeding the raw material aromatics into a fixed-bed alkylation reactor and filling the reactor; then, feeding the raw material aromatics and raw material C6-C... 24 A mixture of long-chain olefins and additive long-chain alkyl aromatic solvents or long-chain alkane solvents is fed into a fixed-bed reactor and contacted with an SBA-15 type mesoporous molecular sieve alkylation solid acid catalyst to carry out the alkylation reaction of aromatics and long-chain olefins, generating long-chain alkyl aromatics as the product. A portion of the effluent from the alkylation reactor is used as the reactor's circulating fluid, while the other portion is sent to a distillation separation system to separate the excess feed and product effluent.

[0010] US5648579A discloses a method for the alkylation reaction of benzene and 1-dodecene using a pulsed feed method. In this method, benzene is continuously fed into the feedstock, while the 1-dodecene feed is stopped at intervals to achieve pulsed feed. The molar ratio of benzene to olefin is between 8 and 20, the number of carbon atoms in the straight-chain olefin is between 10 and 14, and the pulse feed interval is between 10 and 60 mins. Summary of the Invention

[0011] The inventors discovered that periodically rinsing the catalyst with aromatics during the reaction process, and treating it with oxygen-containing gas at a certain temperature and pressure when long-chain olefins are not completely converted, can extend the catalyst's single-cycle life and achieve efficient and stable catalyst regeneration. Based on this, the present invention was developed.

[0012] Therefore, the purpose of this invention is to provide an alkylation method that differs from the prior art. This method can optimize and delay the coking rate of the catalyst, ensure efficient and stable catalyst regeneration, thereby improving the single-cycle life of the alkylation catalyst and ensuring long-term stable operation of the equipment.

[0013] To achieve the above objectives, the present invention provides a solid acid alkylation method, characterized in that an aromatic hydrocarbon and a long-chain olefin are contacted under alkylation reaction conditions and in the presence of a solid acid catalyst to carry out an alkylation reaction to obtain a straight-chain alkyl aromatic hydrocarbon. The method further includes step A: when the conversion rate of the long-chain olefin is ≥99% and the process has been running for 5–36 h, the solid acid catalyst is washed with an aromatic substance at 130–350 °C; and step B: when the conversion rate of the long-chain olefin is <99%, the solid acid catalyst is calcined with an oxygen-containing gas at 400–600 °C.

[0014] In the method of this invention, the aromatic hydrocarbon has a total carbon number of 6 to 18, preferably 6 to 12. The aromatic hydrocarbon has a side chain with a carbon number of 0 to 8, preferably 0 to 4. The aromatic hydrocarbon has a side chain with a carbon number of 0 to 8, preferably 0 to 6, such as benzene, toluene, xylene, diethylbenzene, trimethylbenzene, tetramethylbenzene, and their various isomers. The long-chain olefins are selected from C14. 10 ~C 14 One or more of the long-chain olefins. Preferred long-chain olefins are selected from decene, undecene, dodecene, tridecene, tetradecene, and their isomers.

[0015] The solid acid catalyst contains 20–95 wt% molecular sieves and 5–80 wt% inorganic oxides. The molecular sieves are selected from one or more molecular sieves having FAU, MWW, MOR, and BEA topologies; preferably, the molecular sieve has a FAU topology; more preferably, the molecular sieve is a Y-type molecular sieve.

[0016] This invention reveals that the deactivation of the alkylation reaction of aromatics and long-chain olefins is caused by the blockage of catalyst pores by the heavy alkyl aromatics generated during the reaction. This reaction can be catalyzed not only by Brønsted acids but also by Lewis acids. Therefore, appropriately controlling the catalyst cell size can ensure the integrity of the catalyst crystal structure and guarantee sufficient Brønsted acid active sites for the reaction. Therefore, the Y-zeolite described in this invention has a cell size of 2.448–2.457 nm, preferably 2.452–2.455 nm.

[0017] Further research in this invention revealed that, since heavy alkyl aromatics are key to catalyst deactivation, a specific ratio of mesopores can promote the timely diffusion of macromolecules such as heavy alkyl aromatics from the pores, thus delaying catalyst coking. The ratio of mesopore volume to total pore volume is 0.15–0.29, preferably 0.18–0.26. Both the mesopore volume and total pore volume described in this invention can be determined by static low-temperature nitrogen adsorption capacity method (BET). BET determination is well-known to those skilled in the art; for example, it can be performed using an ASAP2420 adsorption instrument from Mack Company, USA. The determination process is as follows: the sample is first dried in an oven at 110°C for 2 hours to remove surface water. Then, a certain amount of sample is weighed and placed in a degassing unit, evacuated to a vacuum degree less than 1.33 Pa, and treated at 90°C for 1 hour, followed by heating to 330°C for 9–10 hours. The sample is then subjected to nitrogen adsorption-desorption testing under liquid nitrogen cooling conditions to obtain adsorption-desorption curves. The specific surface area and pore volume are calculated using the BET formula.

[0018] The inorganic oxide is selected from one or more of silicon oxide, aluminum oxide, zirconium oxide, and titanium oxide.

[0019] In the method of this invention, in step A, the aromatic hydrocarbon is one or more monocyclic or polycyclic aromatic hydrocarbons; preferably, the aromatic hydrocarbon is the same as the aromatic hydrocarbon used in the alkylation reaction. In step A, the temperature is 200–280°C, preferably 230–270°C; the space velocity of the aromatic hydrocarbon is 1–100 h⁻¹. -1 Preferably 5-60h -1 More preferably 10-30h -1 The rinsing time is 1–72 h, preferably 10–36 h, and more preferably 15–28 h. The temperature is increased from the alkylation reaction temperature to the A step temperature at a rate of 1–20 °C / min, preferably 1–15 °C / min, and more preferably 1–12 °C / min.

[0020] In the method of this invention, in step B, the oxygen-containing gas is a mixture of oxygen and one or more inert gases. Nitrogen is a preferred inert gas. The oxygen volume fraction in the mixture is 1%–99%, preferably 5%–50%, and more preferably 10%–35%. In step B, the oxygen-containing gas flow rate is 20–500 mL / min / g catalyst, preferably 40–400 mL / min / g catalyst, and more preferably 90–200 mL / min / g catalyst; the pressure is 0–5 MPa, preferably 0.1–4 MPa, and more preferably 0.2–3 MPa. Step B is preferably carried out at a constant temperature for 1–20 h, preferably 3–16 h, and more preferably 4–12 h. The temperature of step B is 200–900 °C, preferably 350–750 °C, and more preferably 400–600 °C. The temperature is increased from the alkylation reaction temperature to the temperature of step B at a rate of 1–20 °C / min, preferably 1–15 °C / min, and more preferably 1–12 °C / min.

[0021] In the method of this invention, the alkylation reaction conditions are: temperature 70–280°C, pressure 1.5–4 MPa, and the mass hourly space velocity (HHSV) of the feedstock, including aromatics and long-chain olefins, is 1–20 h⁻¹. -1 .

[0022] The inventors discovered that in the alkylation reaction of aromatic benzene and long-chain olefins catalyzed by solid acid, the deactivation of the solid acid is caused by the blockage of the solid acid pores by the heavy alkyl aromatic macromolecules generated during the reaction. Treating the solid acid with aromatic substances after a period of time in the alkylation reaction can remove most of the carbonized precursors of the heavy alkyl aromatic macromolecules generated in the solid acid pores, thus extending the catalyst's single-cycle lifetime. Furthermore, after the solid acid is deactivated (i.e., manifested as a decrease in long-chain olefin conversion to <99%), calcining the solid acid with oxygen-containing gas can almost completely remove the carbonized components in the solid acid, restoring its catalytic activity. Therefore, the method provided by this invention combines step A (periodic treatment of the solid acid with aromatic substances) when the long-chain olefin conversion is ≥99%, and step B (treatment of the solid acid with oxygen-containing gas) when the long-chain olefin conversion is <99%.

[0023] The inventors further discovered that these two steps alone are far from sufficient. To achieve good LAB selectivity and a 2-LAB ratio while significantly improving the single-cycle life of the solid acid and extending the stable operation time of the device, it is necessary to properly match the operating parameters of steps A and B. For example, the operating parameters in step A, which involves rinsing the solid acid with aromatics, include the interval between two adjacent aromatic rinsings, the heating rate to raise the alkylation reaction temperature to the temperature required for step B, the rinsing temperature, pressure, the mass hourly space velocity (MHV) of the aromatics, and the rinsing time. Similarly, the operating parameters in step B, which involves roasting the solid acid with oxygen-containing gas, include temperature, pressure, the heating rate to raise the alkylation reaction temperature to the temperature required for step B, the oxygen-containing gas flow rate, and the isothermal treatment time. Optimal operating parameters can significantly extend the single-cycle life, provide better alkylation activity and selectivity, and achieve unexpected technical effects. Therefore, the most preferred conditions for the method provided by this invention are: in step A, the temperature is 230–270°C; and the MHV of the aromatics is 10–30 h⁻¹. -1 The rinsing time is 15–28 h, and the temperature is increased from the alkylation reaction temperature to the temperature of step A at a rate of 1–12 °C / min. In step B, the oxygen-containing gas has an oxygen volume fraction of 10%–35%, and the oxygen-containing gas flow rate is 90–200 mL / min / g catalyst; the pressure is 0.2–3 MPa. Step B is carried out at a constant temperature of 400–600 °C for 4–12 h, and the temperature is increased from the alkylation reaction temperature to the temperature of step B at a rate of 1–12 °C / min.

[0024] The solid acid alkylation method provided by this invention can be implemented in various reaction apparatuses, such as fluidized beds, fixed beds, and slurry beds. In this invention, the method is implemented using a fixed bed, but its application is not limited to this.

[0025] The present invention uses two indicators, single-cycle lifetime and product distribution, to evaluate the performance of alkylation reactions.

[0026] in:

[0027] Single-cycle lifetime is based on a long-chain olefin conversion rate ≥ 99%, where the long-chain olefin conversion rate is: x = ((w0 - w)) p () / w0)×100%, where w0 is the mass fraction of long-chain olefins in the feedstock before the reaction; w p This represents the mass fraction of the long-chain olefin after the reaction.

[0028] Product distribution was based on linear alkylbenzenes (LAB) and 2-LAB. The products were analyzed using an Agilent Technologies 7890A gas chromatograph with a DB-5MS column. The column temperature program was 50 °C for 5 min, then increased to 300 °C at a rate of 5 °C / min and held for 5 min. A flame ionization detector (FID) was used with an H₂ flow rate of 40 mL / min, an air flow rate of 400 mL / min, and a N₂ make-up flow rate of 25 mL / min. Detailed Implementation

[0029] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0030] The present invention will be described in detail below through embodiments. It should be understood that the specific embodiments described herein are only for illustration and explanation of the present invention, but do not limit the scope of the present invention.

[0031] Example 1

[0032] This embodiment illustrates the solid acid alkylation reaction method of the present invention.

[0033] The raw material was benzene, the raw material long-chain olefin was n-dodecene, and the solid acid catalyst was prepared by mixing Y molecular sieve (purchased from Sinopec Catalyst Branch) and alumina in a weight ratio of 4:1. The resulting solid acid catalyst was designated A1, wherein the Y molecular sieve had a cell constant of 2.448 nm and a mesopore volume to total pore volume ratio of 0.05.

[0034] The reaction was carried out in a fixed-bed reactor. 5g of solid acid catalyst (Y molecular sieve + alumina) was packed into a fixed-bed reactor with an inner diameter of 10mm and a length of 1m. The reaction temperature was 120℃, the reaction pressure was 3MPa, and the feed mass hourly space velocity (WHSV) was 7h⁻¹. -1 The molar ratio of benzene is 40.

[0035] The single-cycle lifetime of the solid acid catalyst is determined by the breakthrough time of n-dodecene in the product of the alkylation reaction. The single-cycle lifetime refers to the total time (h) during which the catalyst processes the feedstock within the time (h) when the conversion of n-dodecene is ≥99%. The conversion of n-dodecene is obtained by gas chromatography analysis of the product and calculated by the following formula.

[0036] n-Dodecene conversion rate: x = ((w0 - w) p ) / w0)×100%

[0037] w0 represents the mass fraction of n-dodecene in the feedstock before the reaction; w p This represents the mass fraction of n-dodecene after the reaction.

[0038] When the conversion rate of n-dodecene is ≥99%, the catalyst is subjected to the aromatics flushing scheme of step A until the conversion rate of n-dodecene is <99%. Specific conditions are shown in Table 1.

[0039] When the conversion rate of n-dodecene is <99%, the treatment scheme of step B is implemented using oxygen-containing gas, and the specific conditions are shown in Table 2.

[0040] The alkylation results are shown in Table 3. In Table 3, LAB and 2-LAB represent the selectivity of linear alkylbenzenes and 2-LAB in the product.

[0041] Comparative Example 1

[0042] This comparative example is the same as Example 1, except that steps A and B of Example 1 are not used.

[0043] The results of the alkylation reaction are shown in Table 3.

[0044] Comparative Example 2

[0045] This comparative example is the same as Example 1, except that step B of Example 1 was not used. That is, only the aromatic rinsing scheme of step A was used, and the oxygen-containing gas roasting treatment scheme of step B was not used.

[0046] The specific conditions for step A are shown in Table 1, and the results of the alkylation reaction are shown in Table 3.

[0047] Comparative Example 3

[0048] This comparative example is the same as Example 1, except that step A of Example 1 was not used. That is, only the oxygen-containing gas roasting treatment scheme of step B was used, and the aromatic rinsing scheme of step A was not used.

[0049] The specific conditions for step B are shown in Table 1, and the results of the alkylation reaction are shown in Table 3.

[0050] Example 2

[0051] This embodiment illustrates the use of both the aromatic rinsing scheme in step A and the oxygen-containing gas roasting treatment scheme in step B, but under conditions where the aromatic rinsing scheme in step A is not optimal.

[0052] The specific conditions for steps A and B are shown in Table 1, and the results of the alkylation reaction are shown in Table 3.

[0053] Example 3

[0054] This embodiment illustrates the situation where both the aromatic rinsing scheme in step A and the oxygen-containing gas roasting treatment scheme in step B are used, but the oxygen-containing gas roasting treatment scheme in step B is not under optimal conditions.

[0055] The specific conditions for steps A and B are shown in Table 1, and the results of the alkylation reaction are shown in Table 3.

[0056] Table 1

[0057]

[0058] Table 2

[0059]

[0060] Table 3

[0061]

[0062] As can be seen from the results in Table 3, the alkylation performance of p-benzene and n-dodecene described in Example 1 is significantly better than that of Comparative Example 1, which does not employ aromatic rinsing and oxygen-containing gas treatment. Furthermore, even when only one of the two methods, aromatic rinsing or oxygen-containing gas treatment, is used, as in Comparative Examples 2 and 3, the alkylation performance is not optimal. In Examples 2 and 3, where both aromatic rinsing and oxygen-containing gas treatment are used, but at least one of the treatment conditions is not within the optimal range, the alkylation performance is also relatively low.

[0063] The deactivation of the benzene-dodecene alkylation reaction is caused by the blockage of catalyst pores by the heavy alkylbenzenes generated during the reaction. Aromatic flushing after a period of time in the alkylation reaction can remove most of the large molecular carbon precursors generated in the catalyst pores, extending the catalyst's single-cycle life. Furthermore, treating the catalyst with oxygen-containing gas after deactivation can almost completely remove the carbonized components, effectively restoring the catalyst's alkylation activity.

[0064] Comparative Examples 1-3, which did not undergo aromatic flushing and / or oxygen-containing gas treatment, showed significantly poor alkylation single-cycle lifetime, lifetime after 6 oxidation regenerations, LAB selectivity, and 2-LAB selectivity. Examples 2 and 3, which involved alkylation reactions with treatment conditions outside the preferred range, also performed much worse than Example 1.

[0065] The deactivation of the benzene-dodecene alkylation reaction is caused by the blockage of catalyst pores by the heavy alkylbenzenes generated during the reaction. Step A, which involves aromatic flushing after the alkylation reaction has proceeded for a period of time, can remove most of the large molecular carbon precursors generated in the catalyst pores, thus extending the catalyst's single-cycle life. Furthermore, step B, which involves treating the catalyst with oxygen-containing gas after deactivation, can almost completely remove the carbonized components from the catalyst, thereby fully restoring the catalyst's alkylation activity and significantly increasing the stable operating time of the unit.

[0066] Example 4

[0067] Same as Example 1, except that the Y molecular sieve used had a cell constant of 2.453 nm and a mesopore / total pore value of 0.22. The alkylation reaction results are shown in Table 4.

[0068] Example 5

[0069] Same as Example 1, except that the Y molecular sieve used had a cell constant of 2.455 nm and a mesopore / total pore value of 0.18. The alkylation reaction results are shown in Table 4.

[0070] Example 6

[0071] Same as Example 1, except that the Y molecular sieve used had a cell constant of 2.452 nm and a mesopore / total pore value of 0.29. The alkylation reaction results are shown in Table 4.

[0072] Table 4

[0073]

Claims

1. A solid acid alkylation reaction method, characterized in that, A method for obtaining straight-chain alkyl aromatics by contacting aromatics and long-chain olefins in the presence of a solid acid catalyst and performing an alkylation reaction, further comprising: step A, when the conversion rate of long-chain olefins is ≥99%, stopping the feed of aromatics and long-chain olefins every 5-36 hours and rinsing the solid acid catalyst with an aromatic substance at 130-350°C; and step B, when the conversion rate of long-chain olefins is <99%, calcining the solid acid catalyst with an oxygen-containing gas at 400-600°C. The aromatic hydrocarbon has a total carbon number of 6 to 18; the long-chain olefin is selected from C64. 10 ~C 14 The solid acid catalyst contains one or more long-chain olefins; the solid acid catalyst contains 20-95 wt% Y molecular sieve and 5-80 wt% inorganic oxide, wherein the Y molecular sieve has a cell size of 2.448-2.457 nm and a mesopore volume to total pore volume ratio of 0.15-0.

29. In step A: the aromatic substance is one or more monocyclic or polycyclic aromatic hydrocarbons; the temperature for rinsing the solid acid catalyst is 130–350°C, and the space velocity of the aromatic substance is 1–100 h⁻¹. -1 The rinsing time is 1 to 72 hours; The temperature is increased from the alkylation reaction temperature to the temperature of step A at a rate of 1–20 °C / min. In step B, the oxygen-containing gas flow rate is 20–500 mL / min / g catalyst, and the pressure is 0–5 MPa; step B is carried out at a constant temperature for 1–20 h. The temperature is increased from the alkylation reaction temperature to step B at a rate of 1–12 °C / min.

2. The method according to claim 1, characterized in that, The aromatic hydrocarbons have a total carbon number of 6 to 12.

3. The method according to claim 1, characterized in that, The aromatic hydrocarbon side chain has 0 to 8 carbon atoms.

4. The method according to claim 3, characterized in that, The aromatic hydrocarbon side chain has 0 to 6 carbon atoms.

5. The method according to claim 1, characterized in that, The aromatic hydrocarbon is selected from one or more of benzene, toluene, xylene, diethylbenzene, trimethylbenzene, tetramethylbenzene and their isomers.

6. The method according to claim 1, characterized in that, The aromatic hydrocarbon is benzene or toluene.

7. The method according to claim 1, characterized in that, The long-chain olefin is selected from one or more of decene, undecene, dodecene, tridecene, tetradecene, and their isomers.

8. The method according to claim 1, characterized in that, The Y molecular sieve has a cell size of 2.452–2.455 nm and a mesopore volume to total pore volume ratio of 0.18–0.

26.

9. The method according to claim 1, characterized in that, The inorganic oxide is selected from one or more of silicon oxide, aluminum oxide, zirconium oxide, and titanium oxide.

10. The method according to claim 1, characterized in that, In step A, the aromatic hydrocarbon is benzene, toluene, xylene, diethylbenzene, trimethylbenzene, tetramethylbenzene, and their isomers.

11. The method according to claim 1, characterized in that, In step A, the aromatic substance is the same as the aromatic substance in the alkylation reaction.

12. The method according to claim 1, characterized in that, In step A, the temperature for rinsing the solid acid catalyst is 155–280 °C, and the space velocity of the aromatics is 5–60 h⁻¹. -1 The rinsing time is 10 to 36 hours.

13. The method according to claim 1, characterized in that, In step A, the space velocity of the aromatic hydrocarbons is 10–30 h⁻¹. -1 The rinsing time is 15 to 28 hours.

14. The method according to claim 1, characterized in that, The temperature is increased from the alkylation reaction temperature to the temperature of step A at a rate of 1–12 °C / min.

15. The method according to claim 1, characterized in that, In step B, the oxygen-containing gas is a mixture of oxygen and one or more inert gases.

16. The method according to claim 15, characterized in that, The oxygen volume fraction in the mixed gas is 1% to 99%.

17. The method according to claim 16, characterized in that, The oxygen volume fraction in the mixed gas is 5% to 50%.

18. The method according to claim 17, characterized in that, The oxygen volume fraction in the mixed gas is 10% to 35%.

19. The method according to claim 1, characterized in that, In step B, the oxygen-containing gas flow rate is 40–400 mL / min / g catalyst, and the pressure is 0.1–4 MPa.

20. The method according to claim 1, characterized in that, In step B, the oxygen-containing gas flow rate is 90–200 mL / min / g catalyst, and the pressure is 0.2–3 MPa.

21. The method according to claim 1, characterized in that, Step B is carried out at a constant temperature for 3 to 16 hours.

22. The method according to claim 1, characterized in that, The alkylation reaction conditions are a temperature of 70–280 °C, a pressure of 1.5–4 MPa, and a mass hourly space velocity (HHSV) of 1–20 h⁻¹ for the feedstocks, including aromatics and long-chain olefins. -1 .

23. The method according to claim 1, characterized in that, The temperature is increased from the alkylation reaction temperature to the A-step temperature at a rate of 1–12 °C / min; in step A, the temperature is 230–270 °C, and the space velocity of the aromatics is 10–30 h⁻¹. -1 The rinsing time is 15-28 h; the temperature is increased from the alkylation reaction temperature to the temperature of step B at a rate of 1-12 °C / min; in step B, the oxygen-containing gas has an oxygen volume fraction of 10%-35%, a flow rate of 90-200 mL / min / g catalyst, and a pressure of 0.2-3 MPa; step B is carried out at a constant temperature of 400-600 °C for 4-12 h.

24. The method according to claim 1 or 23, characterized in that, Step A is performed multiple times when the conversion rate of long-chain olefins is ≥99%, and Step B is performed multiple times when the conversion rate of long-chain olefins is <99%.

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