RU2312096C1 - Method for preparing linear alkylbenzene using catalyst of micro-mesoporous structure - Google Patents

Abstract

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention proposes a method for synthesis of linear alkylbenzenes involving the alkylation reaction of benzene with (C₈-C₂₀)-alpha-olefin at temperature 100-450⁰C and under pressure 0.2-5 MPa on catalyst of micro-mesoporous structure with part of micropores from 0.03 to 0.90 and part of mesopores from 0.97 to 0.10. Catalyst comprises microporous crystalline silicates of zeolite structure and having the composition of anionic carcass of the formula: T₂O₃(10-1000)SiO₂ wherein T means elements chosen from group consisting of p-element of group III or d-elements of groups IV-VIII, or their mixtures. Catalyst of micro-mesoporous structure comprises, in particular, microporous crystalline silicate of zeolite structure of the following type: FAU, LTL, FER, MAZ, MOR, BEA, MFI, MEL and MTW. Invention provides increasing yield of linear alkylbenzenes and with high selectivity by sum of linear alkylbenzenes and 2-phenyl isomer and in retaining catalytic stability of catalyst.

EFFECT: improved method of synthesis.

6 cl, 2 tbl, 2 dwg, 29 ex

Description

The present invention relates to a method for producing linear alkylbenzenes. The invention will find application in the processes of petrochemistry, oil refining and organic synthesis.

Linear alkylbenzenes (LABs) having chains typically containing 10-14 carbon atoms are commercially available products that are further sulfonated to produce surfactants. widely used in the manufacture of detergents.

To date, it is recognized that the method for producing LAB with a high conversion of alpha-olefin, high selectivity for the formation of a 2-phenylisomer, which is characterized by increased solubility and, accordingly, improved washing properties, as well as a good susceptibility to microbiological degradation in nature and long operating time of the used one, is relevant. catalyst.

In industry, LABs are usually prepared using the classical Friedel-Crafts reaction on homogeneous Lewis (AlCl ₃ ) or Brestod acids (HF). The above methods due to the use of these catalysts are characterized by the absence of a stereoselective effect under homogeneous conditions and the formation of hazardous waste during the isolation of target products from the mixture, which have a corrosive effect on structural materials.

A known method of obtaining LAB, carried out in the presence of a heterogeneous catalyst for fluorinated aluminosilicate prepared by impregnation of aluminosilicate HF (US 4,463,205, US 5,196,574, US 5,334,793, US 4,463,205, US 6,521,804). The alkylbenzenes obtained using this catalyst have 95% linearity with a content of the main by-product, tetralin, of less than 0.5%. This process is characterized by low selectivity for the formation of the most important 2-phenylisomer in a mixture of linear isomers, the proportion of which is only 25%.

Known methods for producing LAB by alkylation of benzene with alpha-olefins in the presence of heterogeneous catalysts: mordenite zeolite (US 6,448,458, US 5,770,782, US 5,019,669, US 5,146,026, US 6,315,964), BETA (US 7,008,914, US 6,448,458, US 5,770,782, US NES (US 6,448,458), X, Y, USY, MSM-22 (US 5,191,135), A, X, Y, L, erionite and omega (US 5,019,669), bentonite, montmorillonite, hectorite, saponite, chlorite, ilite, galloisite, faujasite, kaolinite, sepiolite, paligorskite, chabazite and erionite (US 5,146,0265).

With a high conversion of alpha-olefins (95-100%), the obtained LABs are characterized by low selectivities for the sum of linear alkylbenzenes and 2-phenylisomers. The low selectivity of the target product depends on the application of all of the above traditional zeolites, both natural and synthetic. In addition, these catalysts are unstable due to rapid deactivation. These catalysts have a micropore system with a diameter of less than 2 nm, which leads to difficulties in the mass transfer of reagent molecules to the active centers of the zeolite located inside its channels, as well as reaction products from the reaction zone.

The closest is the method of obtaining LAB with high yields of 2-phenylisomer using offretitis, ZSM-12, dealuminated mordenitis. The catalyst can be used in pure form, can be subjected to heat treatment before use, or molded with a binder, for example, Al ₂ O ₃ (US 4,301,317).

However, the described process is characterized by instability due to the rapid deactivation of the catalyst, determined by its structure, characterized by the presence of narrow transport pores of the zeolite with a channel diameter or mouth pores of 6-7 Å.

The present invention is based on the technical task to develop a method for producing linear acylbenzenes through the use of a catalyst with a micromesoporous structure and an appropriate selection of technological parameters, which would provide high selectivity for the formation of linear alkylbenzenes, mainly 2-phenylisomers, with high catalytic stability of the catalyst.

The problem is solved in that a method for producing linear alkylbenzenes by alkylating benzene with an alpha-olefin having from 8 to 20 carbon atoms, at a temperature of 50-450 ° C and a pressure of 0.2-5 MPa on a catalyst with a micromesoporous structure, characterized by a micropore fraction of 0.03 to 0.90 and fractions of mesopores from 0.97 to 0.10, including microporous crystalline silicates with a zeolite structure having the composition of the anionic framework T ₂ O ₃ (10-1000) SiO ₂ , where T are elements selected from the group consisting of p-elements of group III or d-elements of group IV-VIII, silt mixtures thereof.

The technical result is to increase the yield of linear alkylbenzenes with high selectivity by the sum of linear alkylbenzenes and 2-phenylisomer while maintaining the catalytic stability of the catalyst.

The use of a catalyst that combines the advantages of zeolites and mesoporous molecular sieves, the structure of which increases the access of reactants and reaction products to its active centers, as well as the appropriate selection of temperature parameters and pressures that are optimal for the alkylation process and catalyst operation, ensure the achievement of the named technical result.

The interaction of benzene with an alpha-olefin having a linear chain of 8 to 20 carbon atoms is advisable to be carried out under continuous flow in a reactor with a fixed catalyst bed under liquid-phase or gas-liquid phase alkylation at a mass feed rate of 0.5 to 330 g / g · h and a molar ratio of benzene to alpha olefin of from 4: 1 to 10: 1 in the presence of an inert gas, for example nitrogen. The diluent gas transmission rate should be used in the range of 5-50 ml / min. In this case, the maximum conversion of olefins and high stability of the catalyst.

It is advisable to carry out the alkylation at a temperature of from 100 to 300 ° C, a pressure of 1 MPa to 3 MPa, a feed rate of 1 to 3 g / g · h and a molar ratio of benzene to alpha-olefin of 7-9: 1. Under such conditions, the maximum selectivity of the formation of the target product, mainly 2-phenylisomer, is achieved.

The implementation of the conversion at lower temperatures and at higher feed rates of the reagents and high pressure leads to a noticeable decrease in the conversion of the feedstock. Conversion at higher temperatures and at lower feed rates of reagents and pressure leads to a noticeable increase in the formation of reaction by-products, mainly crack products, and, consequently, to a decrease in selectivity for the target reaction products. Carrying out the process with a molar ratio of benzene to alpha-olefin of 4-10: 1. predominantly 7-9: 1, it is advisable, since at a lower benzene content the olefin is poorly soluble in benzene, in addition, the isomerization and oligomerization of olefin are intensively carried out, while at a higher benzene content the reaction becomes economically disadvantageous.

It is advisable to use silicates with the structure of zeolites FAU, LTL, FER, MAZ, MOR, BEA, MFI, MEL, MTW as microporous crystalline silicates.

The invention will be further described in detail in the description and examples of its implementation with reference to the accompanying drawings, in which according to the invention:

Figure 1 depicts the diffraction patterns of the starting aluminosilicates and used in the catalyst process.

Figure 2 depicts the isotherms of low-temperature adsorption-desorption of nitrogen of the starting aluminosilicates and used in the catalyst process.

The proposed method for the alkylation of benzene with an alpha olefin is as follows. Preliminary preparation of the catalyst is carried out by heating in a stream of inert gas (nitrogen, helium) to 350 ° C for 1 hour and calcining at this temperature for 30 minutes, then the reactor is cooled to an alkylation temperature. A mixture of benzene with an alpha-olefin is fed to a fixed flow catalyst type reactor. The process is carried out under a pressure of 0.2-5 MPa in the temperature range of 50-450 ° C. The feed rate is selected in the range from 0.5 to 330 g / g · h, the molar ratio of benzene: olefin is from 4: 1 to 10: 1 in the presence of an inert gas, for example nitrogen. The transmission rate of the diluent gas is taken in the range of 5-50 ml / min.

At the outlet of the reactor, the resulting products are separated into liquid and gaseous, the component composition is determined by chromatographic method. The results of the alkylation process (table 2) are presented one hour after the start of the reaction, which corresponds to the establishment of a stationary mode in the system.

A catalyst with a micromesoporous structure is obtained by suspending microporous crystalline silicates with a zeolite structure having a composition of T ₂ O ₃ (10-1000) SiO ₂ in an alkaline solution until the residual zeolite content in the suspension is 3-90 wt.%, The silicate is introduced into the suspension a solution of a cationic surfactant, followed by the addition of acid to form a gel and hydrothermal treatment of the gel with the release of the finished product.

Along with silicon atoms, forming a silicate crystal lattice, Al or Ga, or B, or Fe, or Zn, or Ti, or Zr, or V, or Cr, or a mixture thereof are used.

The obtained micromesoporous catalyst retains the crystalline structure of the starting microporous crystalline silicate, as can be seen in Fig. 1, where curve 1 shows the diffraction pattern of microporous aluminosilicate with the MOR structure, curve 2 shows the diffraction pattern of the catalyst with micromesoporous structure obtained from the aluminosilicate with the MOR structure, and - a diffraction pattern of an aluminosilicate with a known mesoporous structure that is not crystalline.

Suspension of microporous crystalline silicates is carried out in an alkaline solution with a concentration of hydroxide ions of 0.2-1.5 mol / L, after which the alkaline suspension of zeolite is mixed with a solution of cationic surfactant and acid is added until a gel is formed with a pH of 7.5-9.0.

Hydrothermal treatment of the gel is carried out at a temperature of 100-150 ° C at atmospheric pressure or in an autoclave for 10-72 hours.

Quaternary alkylammonium salts of the composition С _n Н _{2n + 1} (СН ₃ ) ₃ NAn, where n = 12-18, An - Cl, Br, HSO ₄ ^- , which provide electrostatic interaction between negatively charged (in as a result of adsorption of hydroxide ions) by highly dispersed crystal fragments of the initial silicate and silicate ions and positively charged micelles of a surfactant. As a result of this interaction, a mesoporous phase is formed.

Pore volume, micropore fraction and mesopore fraction are calculated from isotherms of low-temperature nitrogen adsorption, as shown in Fig. 2, where curve 4 depicts the isotherm of low-temperature nitrogen adsorption-desorption for microporous silicate with the MFI zeolite structure, curve 5 shows the isotherm of low-temperature nitrogen adsorption-desorption material with a micromesoporous structure, obtained on the basis of microporous silicate with the structure of the zeolite MFI, curve 6 is the isotherm of low-temperature adsorption-desorption of nitrogen for the known silicate with mesoporous oh structure. As follows from figure 2, the adsorption isotherm of the micromesoporous catalyst (curve 5) is similar to the isotherm of the mesoporous catalyst (curve 6), which indicates the formation of a developed regular structure. The location of the isotherms of the micromesoporous catalyst (curve 5) and microporous silicate (curve 6) indicates a 2.5-fold increase in pore volume.

A feature of the catalyst with a micromesoporous structure is the presence of two types of pores - micropores (whose share in the total pore volume of the material is 0.03-0.90) and mesopores (whose share in the total pore volume of the material is 0.10-0.97). The presence of micropores is due to the presence of highly dispersed fragments of microporous crystalline silicates homogeneously distributed in the bulk of the mesoporous phase formed by the stereoregular mesopore system.

To obtain micromesoporous catalysts, microporous crystalline silicates of different crystal structures and different chemical compositions were used, the properties of which are presented in Table 1.

Table 1 Structure Structure Pore volume, cm ³ / g The proportion of micropores one Mor Al ₂ O ₃ 97SiO ₂ 0.195 1.0 2 Bea Al ₂ O ₃ 84 SiO ₂ 0.184 1.0 3 Mfi Al ₂ About ₃ 80SiO ₂ 0.164 1.0

Commercially available mordenite with a SiO ₂ / Al ₂ O ₃ = 97 (MOR) ratio, beta with a SiO ₂ / Al ₂ O ₃ = 84 ratio (BEA), and ZSM-5 with a SiO ₂ / Al ratio are used as initial microporous zeolites. ₂ O ₃ = 80 (MFI).

The following examples illustrate the invention, but do not limit it.

Example 1

Preparation of Micromesoporous Catalyst (ReMOR).

5 g of microporous crystalline aluminosilicate with a mordenite structure are added to 30 ml of a 0.48 mol / L NaOH solution. The resulting suspension was stirred at room temperature for 0.5 h, after which it was mixed with a solution of 7.76 g of hexadecyltrimethyl ammonium bromide (C ₁₆ H ₃₃ (CH ₃ ) ₃ NBr) in 48 ml of H ₂ O. 10 ml of 2 mol / L hydrochloric acid was added to the resulting mixture. acid to gel with a pH of 7.5. After homogenizing the gel for 0.5 h, it is transferred to an autoclave, which is closed and heated for 24 h at 110 ° C. At the end of the hydrothermal treatment, the material is separated on the filter, washed with distilled water, dried at 100 ° C for 24 hours, calcined at 550 ° C for 24 hours. As a result, a micromesoporous catalyst with a zeolite mordenite structure with a pore volume of 0.360 cm ³ / g is obtained , with fractions of micropores and mesopores in the pore volume of 0.48 and 0.52, respectively.

Example 2

Alkylation of benzene with dodecene-1.

The micromesoporous catalyst obtained in example 1 is placed in a flow reactor, purged with nitrogen at a temperature of 350 ° C for 1 hour and calcined at this temperature for 30 minutes, then the temperature is reduced to 100 ° C and a mixture of benzene with dodecene-1 is fed at a pressure of 3 MPa, a feed rate of 2.5 g / g · h, a molar ratio of benzene: dodecene-1 = 8: 1 The diluent gas speed N ₂ 10 ml / min. The experimental results are presented in table 2.

Example 3-11

The process of alkylation of benzene with dodecene-1 is carried out analogously to example 2, the difference is that the process conditions are changed: temperature, pressure, feed rate of the reagents, as well as the molar ratio of benzene: dodecene-1. The experimental conditions and results are presented in table 2.

Example 12

Similar to example 2, the difference is that an alpha-olefin of composition C ₂₀ H _{40 was} used as the alkylating agent. The experimental results are presented in table 2.

Example 13

Similar to example 2, the difference is that as the alkylating agent used alpha-olefin composition C ₈ H ₁₆ . The experimental results are presented in table 2.

Example 14

Similar to example 2, the difference is that the results are presented 6 hours after the start of the experiment. The experimental results are presented in table 2.

Example 15

Similar to example 2, the difference is that they use a microporous catalyst MOR. The experimental results are presented in table 2.

Example 16

The catalyst is prepared analogously to example 1, but 5 g of a microporous crystalline aluminosilicate with a mordenite structure are added to 30 ml of a 1.6 mol / L NaOH solution. The result is a micromesoporous catalyst with a mordenite zeolite structure, pore volume of 0.850 cm ³ / g, with fractions of micropores and mesopores in the pore volume of 0.03 and 0.97, respectively.

Example 17

Similar to example 2, the difference is that they use the catalyst described in example 16. The results of the experiment are presented in table 2.

Example 18

A micromesoporous catalyst (ReBEA) is prepared as follows: 5 g of a microporous crystalline aluminosilicate with a BEA structure are added to 30 ml of a 0.75 mol / L NaOH solution. The resulting suspension was stirred at room temperature for 0.5 h, after which it was mixed with a solution of 6.56 g of dodecyl trimethylammonium bromide (C ₁₂ H ₂₅ (CH ₃ ) ₃ NBr) in 48 ml of H ₂ O. To the resulting mixture was added 10 ml of 2 mol / L hydrochloric acid to gel with a pH of 9.0. After homogenizing the gel for 0.5 h, it is transferred to an autoclave, which is closed and heated for 72 h at 100 ° C. At the end of the hydrothermal treatment, the material is separated on the filter, washed with distilled water, dried at 100 ° C for 24 hours, calcined at 550 ° C for 24 hours. As a result, a micromesoporous catalyst with a BEA zeolite structure with a pore volume of 0.760 cm ³ / g is obtained , with fractions of micropores and mesopores in the pore volume of 0.18 and 0.82, respectively.

Example 19

Similar to example 2, the difference is that a mixture of benzene with dodecene-1 is supplied at a temperature of 100 ° C, a pressure of 3 MPa, a feed rate of 330 g / g · h, a molar ratio of benzene: dodecene-1 = 8: 1. In this case, use the catalyst described in example 18. The experimental results are presented in table 2.

Example 20

A micromesoporous catalyst (FeReMOR) is prepared as follows: 5 g of a microporous crystalline silicate with a MOR structure are added to 30 ml of a 1.0 mol / L NaOH solution. The resulting suspension was stirred at room temperature for 2 hours, after which it was mixed with a solution of 7.76 g of cetyltrimethylammonium bromide (C ₁₆ H ₃₃ (CH ₃ ) ₃ NBr) in 48 ml of H ₂ O. 15 ml of 2 mol / L hydrochloric acid was added to the resulting mixture. acid to form a gel with a pH of 8. After homogenizing the gel for 1 h, it is transferred to an autoclave, which is closed and heated for 48 h at 110 ° C. At the end of hydrothermal treatment, the catalyst is separated on a filter, washed with distilled water, dried at 100 ° C for 24 hours, calcined at 550 ° C for 24 hours. As a result, a material with a MOR zeolite structure of SiO ₂ / Fe ₂ O ₃ = 20, pore volume 0.50 cm ³ / g, with fractions of micropores and mesopores in the pore volume 0.20 and 0.80, respectively.

Example 21

Similar to example 19, the difference is that they use the catalyst described in example 20. The results of the experiment are presented in table 2.

Example 22

Similar to Example 20, the difference is that a microporous crystalline iron aluminum silicate with a MOR zeolite structure is used to prepare a micromesoporous catalyst (FeAlReMOR), a gel with a pH of 8 is obtained by adding 10 ml of 2 mol / L hydrochloric acid, and hydrothermal treatment is carried out for 24 hours. The result is a catalyst with a mordenite zeolite structure (MOR), composition Al ₂ O ₃ · Fe ₂ O ₃ · 50SiO ₂ , pore volume 0.65 cm ³ / g, with fractions of micropores and mesopores in the pore volume 0.30 and 0.70, respectively.

Example 23

Similar to example 19, the difference is that they use the catalyst described in example 22. The results of the experiment are presented in table 2.

Example 24

Similar to Example 22, the difference is that for the preparation of the micromesoporous catalyst (GaReBEA), a 1.5 mol / L NaOH solution, a microporous crystalline gallosilicate with a BEA zeolite structure are used, 8.40 g octadodecyl trimethylammonium bromide (C ₁₈ H ₃₇ (CH ₃ ) ₃ NBr). The result is a catalyst with a BEA zeolite structure, with a SiO ₂ / Ga ₂ O ₃ ratio of 50, a pore volume of 0.45 cm ³ / g, and micropores and mesopores in the pore volume of 0.38 and 0.62, respectively.

Example 25

Similar to example 19, the difference is that they use the catalyst described in example 24. The results of the experiment are presented in table 2.

Example 26

Similar to Example 20, the difference is that for the preparation of a micromesoporous catalyst (TiAlReBEA), a 5.5 mol / L KOH solution, a microporous crystalline titanoaluminosilicate with a BEA structure are used, the suspension is stirred for 0.5 h, the hydrothermal treatment is carried out for 24 hours at 150 ° C. The result is a catalyst with the structure of BEA zeolite, composition Al ₂ O ₃ · TiO ₂ · 70SiO ₂ with a pore volume of 0.65 cm ³ / g, with fractions of micropores and mesopores in the pore volume of 0.10 and 0.90, respectively.

Example 27

Similar to example 19, the difference is that they use the catalyst described in example 26. The results of the experiment are presented in table 2.

Example 28

Similar to Example 22, the difference is that for the preparation of the micromesoporous catalyst (ReMFI) they use a 0.5 mol / L NaOH solution, a microporous crystalline aluminosilicate with an MFI structure, the suspension is stirred for 1 h, 7.76 g of hexadecyltrimethylammonium bromide (С ₁₆ Н ₃₃ (CH ₃ ) ₃ NBr). The result is a micromesoporous catalyst with an MFI zeolite structure with a pore volume of 0.510 cm ³ / g, with fractions of micropores and mesopores in the pore volume of 0.20 and 0.80, respectively.

Example 29

Similar to example 19, the difference is that they use the catalyst described in example 28. The results of the experiment are presented in table 2.

table 2 Example No. Catalyst T, ° C R, MPa Mass feed rate, g / g / h Benzene: Olefin Properties of the catalyst with a micromesoporous structure The conversion of olefin,% Yield of 1 phenylalkanes, mol% The content in the group of phenylalkanes, wt.% pore volume, cm / g micropore fraction mesopore fraction Linear phenylalkanes 2-phenylalkane 2 Remor one hundred thirty 2.5 8: 1 0.360 0.48 0.52 100.0 70.8 91.4 71.3 3 Remor one hundred thirty twenty 8: 1 0.360 0.48 0.52 99.4 73.8 91.4 71.7 four Remor one hundred thirty 330 8: 1 0.360 0.48 0.52 63.3 26.5 97.1 82.0 5 Remor one hundred 0.2 5 8: 1 0.360 0.48 0.52 100.0 41.1 89.5 65.9 6 Remor one hundred 0.9 5 8: 1 0.360 0.48 0.52 100.0 68.3 91.3 70.8 7 Remor fifty thirty 5 8: 1 0.360 0.48 0.52 99.6 72.6 92.8 77.8 8 Remor 230 thirty 5 8: 1 0.360 0.48 0.52 97.2 28.4 36.4 10.9 9 Remor 450 fifty 0.5 8: 1 0.360 0.48 0.52 100.0 10.0 21.4 5.3 10 Remor one hundred thirty 330 4: 1 0.360 0.48 0.52 99.4 5.0 65.8 20.3 eleven Remor one hundred thirty 330 10: 1 0.360 0.48 0.52 64.8 37.1 99.7 84.9 12 Remor one hundred thirty 330 8: 1 0.360 0.48 0.52 40.5 10.2 87.0 67.9 13 Remor one hundred thirty 330 8: 1 0.360 0.48 0.52 87.9 44.6 98.1 74.7 fourteen Remor one hundred thirty 2.5 8: 1 0.360 0.48 0.52 100.0 74.4 91.5 71.5 fifteen Mor one hundred thirty 330 8: 1 0.240 1.0 0.0 66.0 15.0 90.5 83.6 17 Remor one hundred thirty 330 8: 1 0.850 0.03 0.97 26.9 1.8 87.3 72.3 19 Reba one hundred thirty 330 8: 1 0.760 0.18 0.82 59.4 6.6 91.0 72.2 21 FeReMOR one hundred thirty 330 8: 1 0.500 0.20 0.80 59.2 23.0 98.5 81.2 23 FeAlReMOR one hundred thirty 330 8: 1 0.650 0.30 0.70 61.7 19.7 94.9 78.6 25 GaRebea one hundred thirty 330 8: 1 0.450 0.38 0.62 58.0 22.3 91.2 76.1 27 TiAlReBEA one hundred thirty 330 8: 1 0.650 0.90 0.10 60.1 18.4 95.4 78.2 29th Remi one hundred thirty 330 8: 1 0.510 0.20 0.80 18.2 9.8 98.3 88.1

Claims (6)

1. The method of producing linear alkylbenzenes by alkylation of benzene with an alpha olefin having from 8 to 20 carbon atoms, at a temperature of 50-450 ° C and a pressure of 0.2-5 MPa on a catalyst with a micromesoporous structure, characterized by a micropore fraction of from 0.03 to 0.90 and mesopore fractions from 0.97 to 0.10, including microporous crystalline silicates with a zeolite structure having the composition of the anionic framework T ₂ O ₃ (10-1000) SiO ₂ , where T are elements selected from the group consisting of p-elements of group III or d-elements of group IV-VIII, or mixtures thereof. 2. The method according to claim 1, characterized in that the named alpha olefin having 12 carbon atoms is used. 3. The method according to claim 1, characterized in that said process is carried out under continuous flow conditions in a reactor with a fixed catalyst bed and under gas-liquid phase alkylation conditions. 4. The method according to any one of claims 1 to 3, characterized in that the alkylation is carried out at a feed rate of from 0.5 to 330 g / (g · h) and a molar ratio of benzene to alpha-olefin of 4-10: 1 in the presence of inert gas. 5. The method according to any one of claims 2 and 3, characterized in that the said process is carried out at a temperature of from 100 to 300 ° C, a pressure of 1 MPa to 3 MPa, a feed rate of 1 to 3 g / (g · h) and a molar ratio of benzene to alpha olefin of from 7-9: 1 in the presence of nitrogen. 6. The method according to claim 1, characterized in that the said catalyst with a micromesoporous structure includes a microporous crystalline silicate with a zeolite structure of the type FAU, LTL, FER, MAZ, MOR, BEA, MFI, MEL, MTW.

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