Composite adsorbent for separating ethylbenzene by adsorption distillation and its application

Abstract

A composite adsorbent for separating ethylbenzene from C arenes by adsorptive distillation, comprising 1-50 wt. % of a xylene adsorbent and 50-99 wt. % of a carrier liquid, wherein the carrier liquid is selected from one or two of an alkane, an aryl-substituted alkane, decalin, and an alkyl-substituted decalin, and the alkane is a C 10 -C 26 alkane, and the aryl-substituted alkane is C 13 -C 16 The composite adsorbent can enhance the volatility of ethylbenzene compared with other C8 arenes, thus enabling separation of high-purity ethylbenzene from C8 arenes by adsorptive distillation.

Description

Technical Field

[0001] The present invention relates to a composite adsorbent for adsorption distillation separation and its application, and specifically to a method for separating ethylbenzene from C8 arenes by adsorption distillation using the composite adsorbent.

Background Art

[0002] Ethylbenzene is an important basic chemical substance mainly used in the production of styrene. Currently, ethylbenzene is mainly produced by the alkylation of benzene and ethylene. In the petroleum refining and chemical industries, there are abundant ethylbenzene resources. Ethylbenzene accounts for about 18% by mass of the reformed C8 fraction and about 50% by mass of the ethylene cracking C8 fraction. If this part of ethylbenzene can be directly separated, the usage amounts of ethylene and benzene can be saved, and the distribution of chemical industrial resources can be optimized. Furthermore, after separating ethylbenzene from the C8 fraction, using xylene that does not contain ethylbenzene or has a significantly reduced amount of ethylbenzene as the raw material of the arene complex plant can significantly improve the function of the arene complex plant. Therefore, it is necessary to develop a new method for efficiently separating ethylbenzene from mixed C8 arenes.

[0003] Currently, there are three methods for separating ethylbenzene from C8 arenes: the superfractionation method, the adsorption method, and the extraction method. Separating ethylbenzene from the C8 fraction using the superfractionation method is a traditional method. Since the boiling points of the four isomers of mixed C8 arenes are close, and the boiling point difference between ethylbenzene and p-xylene is only 2.2 °C, it is difficult to separate them by distillation.

[0004] GB1198592 describes a method for separating C8 arenes using a single or multiple distillation columns, which requires at least 250, preferably 365, trays and a reflux ratio of 100 - 250:1. This method can separate a mixture of ethylbenzene, ortho-xylene, para-xylene, and meta-xylene by distillation. Para-xylene is further separated from the mixture of para-xylene and meta-xylene by crystallization, and the other components are isomerized. This method has high energy consumption and no economic advantages.

[0005] There are two types of separation of ethylbenzene by adsorption. One is to preferentially adsorb the non-ethylbenzene components of C8 arenes to obtain an ethylbenzene product from the raffinate. For example, US3917734, US4079094, and US4108915 respectively use Ca-X / Y, Sr-K-X, or Sr-X zeolites to preferentially adsorb the xylene isomers of C8 arenes to obtain an ethylbenzene product from the raffinate. However, it is difficult to obtain a high-purity ethylbenzene product using such adsorbents, and its purity is easily affected by the composition of the raw material. The other is to preferentially adsorb ethylbenzene. CN100577617C discloses a method for separating ethylbenzene and para-xylene in a mixed C8 arene using the pressure swing adsorption method. During the separation by pressure swing adsorption, a purge gas is used to purge the adsorption bed layer, and the adsorbent used is a ZSM-5 molecular sieve. Such an adsorbent adsorbs both p-xylene and ethylbenzene as attractants and cannot separate them. The selectivity of the adsorbent for the target products p-xylene and ethylbenzene is low.

[0006] The extractive distillation method is a method of using an extractant to increase the relative volatility of the components to be separated in order to improve the separation efficiency. The solvents currently reported for separating ethylbenzene by extractive distillation cannot provide ideal selectivity, and the separation efficiency is low.

[0007] US4292142 discloses a method for separating ethylbenzene and para-xylene by extractive distillation. Maleic anhydride and phthalic anhydride are used as a composite solvent for extractive distillation. An oxygen-containing compound can be further added to lower the freezing points of maleic anhydride and phthalic anhydride. Under the condition that the solvent ratio is 1.5, the relative volatility of ethylbenzene and p-xylene reaches 1.22.

[0008] US5135620 discloses a method for separating ethylbenzene from C8 arenes by extractive distillation, using a copper(I) salt of a hydrocarbon sulfonic acid as an entrainer to separate ethylbenzene from C8 arenes by extractive distillation. The sulfonic acid includes p-toluenesulfonic acid, p-dodecylbenzenesulfonic acid, p-hexadecylbenzenesulfonic acid, naphthalenesulfonic acid, phenolsulfonic acid, naphtholsulfonic acid or halogenobenzenesulfonic acid. First, the entrainer is introduced into the extractive distillation column, the component rich in ethylbenzene is discharged from the top of the column, and the entrainer dissolved with xylene is discharged from the bottom of the column. Xylene and the entrainer can be separated through the distillation column. Xylene is discharged from the top of the column, and the entrainer dissolved with xylene is discharged from the bottom of the column and returned to the extractive distillation column. Under the condition that the solvent ratio is 2, the relative volatility of ethylbenzene and p-xylene reaches 1.16.

Summary of the Invention

[0009] The object of the present invention is to provide a composite adsorbent for separating ethylbenzene from C8 arenes by adsorption distillation and its application. The composite adsorbent can enhance the volatility of ethylbenzene compared with other C8 arenes, and thus high-purity ethylbenzene can be separated from C8 arenes by adsorption distillation.

[0010] The composite adsorbent provided by the present invention for separating ethylbenzene from C8 arenes by adsorption distillation comprises 1 to 50% by mass of a xylene adsorbent and 50 to 99% by mass of a carrier liquid, and the carrier liquid is selected from one or two of alkanes, aryl-substituted alkanes, decalin, and alkyl-substituted decalins. The alkane is C 10 -C 26 alkane, and the aryl-substituted alkane is C 13 -C 16 aryl-substituted alkane.

[0011] The composite adsorbent provided by the present invention is obtained by mixing an appropriate amount of a xylene adsorbent with a carrier liquid. It can be used to separate ethylbenzene and xylene from C8 arenes by the method of adsorption distillation to obtain a high-purity ethylbenzene product. The method can reduce the fixed investment and the energy consumption for separating ethylbenzene.

Brief Description of the Drawings

[0012]

Figure 1

Embodiments for Carrying Out the Invention

[0013] The composite adsorbent provided by the present invention comprises a xylene adsorbent and a carrier liquid. The xylene adsorbent adsorbs xylene in the adsorption distillation process and can easily separate ethylbenzene from the xylene of C8 arenes. The carrier liquid is used to carry the xylene adsorbent to flow, does not react with C8 arenes, and preferably has a boiling point of 180 °C or higher. Thus, in the adsorption distillation process, the carrier liquid does not volatilize at the top of the adsorption distillation column, and the adsorbent adsorbed with xylene can be carried to the distillation desorption column. The xylene of the adsorbent is desorbed in the distillation desorption column. The carrier liquid carries the regenerated xylene adsorbent and returns it to the adsorption distillation column for reuse. The adsorbent can significantly increase the volatility of ethylbenzene with respect to each isomer of xylene, and high-purity ethylbenzene can be separated from C8 arenes by adsorption distillation.

[0014] The xylene adsorbent of the composite adsorbent of the present invention is used to increase the relative volatility of ethylbenzene with respect to each isomer of xylene, and the carrier liquid is used to carry the xylene adsorbent to flow. The composite adsorbent preferably contains 5 to 35% by mass of the xylene adsorbent and 65 to 95% by mass of the carrier liquid.

[0015] The xylene adsorbent is preferably a Y zeolite having group IA and / or group IIA metal ions occupying cation sites, and the group IA metal ions are preferably Li + or Na + and the group IIA metal ions are preferably Sr 2+ or Ba 2+ and more preferably NaY zeolite.

[0016] The particle size of the crystal particles of the Y zeolite is preferably 0.1 to 2 microns, more preferably 0.2 to 1.5 microns.

[0017] The carrier liquid is selected from one or any two of alkanes, aryl-substituted alkanes, decalin, and alkyl-substituted decalin, and the alkane is n-alkane or isoalkane, preferably C 10 -C24 n-alkane, more preferably C 11 -C 20 n-alkane.

[0018] The aryl-substituted alkane is preferably C 13 -C 16 diphenylalkane.

[0019] The alkyl of the alkyl-substituted decalin is C1-C 12 alkyl, preferably C3-C 10 alkyl, more preferably C2-C6 alkyl, may be. The number of substituted alkyls can be 1 to 4, preferably 1 to 2.

[0020] The method for separating ethylbenzene by adsorption distillation provided by the present invention includes a step of introducing a C8 arene mixture into the central part of an adsorption distillation column. The composite adsorbent of the present invention is introduced into the upper part of the adsorption distillation column. After adsorption distillation, ethylbenzene is discharged from the top of the adsorption distillation column, and the composite adsorbent rich in xylene is discharged from the bottom of the column and enters the central part of a distillation desorption column. After distillation desorption, the mixed xylene is discharged from the top of the column, and the regenerated composite adsorbent is obtained at the bottom of the column and returned to the upper part of the adsorption distillation column for reuse.

[0021] In the above method, the top pressure of the adsorption distillation column is preferably 0.01 to 0.2 MPa. The theoretical number of trays is preferably 30 to 100, more preferably 30 to 80. The composite adsorbent preferably enters the column at a temperature of 90 to 130 °C, the bottom temperature of the column is preferably 140 to 250 °C, and the top temperature of the column is preferably 70 to 100 °C.

[0022] The mass ratio of the composite adsorbent to the C8 aromatic hydrocarbon mixture entering the adsorption distillation column is preferably 5 to 30, more preferably 8 to 23. The mass ratio of the xylene adsorbent in the composite adsorbent to the C8 aromatic hydrocarbon mixture is preferably 1.5 to 6, more preferably 2 to 5. The mass ratio of the carrier liquid to the xylene adsorbent is preferably 1.5 to 20, more preferably 2 to 10. The reflux ratio at the upper part of the column is preferably 1 to 15, more preferably 1 to 8.

[0023] The top pressure of the distillation desorption column is preferably 0.01 to 0.15 MPa, more preferably 0.01 to 0.06 MPa. The theoretical number of trays is preferably 20 to 50, more preferably 25 to 45. The bottom temperature of the column is preferably 160 to 280 °C, and the top temperature of the column is preferably 60 to 90 °C. The reflux ratio at the upper part of the distillation desorption column is preferably 0.3 to 3, more preferably 0.5 to 2.

[0024] In the above method, the reflux ratio is the mass ratio of the material returning to the upper part of the column to the material discharged from the top of the column.

[0025] The adsorption distillation column and the distillation desorption column may be a packed column or a plate column.

[0026] In the present invention, the ethylbenzene content in the C8 aromatic hydrocarbon mixture is preferably 10 to 85% by mass, more preferably 15 to 60% by mass.

[0027] In adsorption distillation, the relative volatility is used to represent the separation effect of the solvent. The relative volatility (α) can reflect the difficulty of separating two components in the distillation process, and refers to the ratio of the volatility of the easily volatile component i to the volatility of the hardly volatile component j in the solution to be separated. The relative volatility of the two components i and j separated when reaching the gas-liquid equilibrium is calculated using Equation (1).

[0028]

Equation

[0029] In formula (1), x is the liquid-phase molar fraction of the component in the equilibrium state, and y is the gas-phase molar fraction of the component in the equilibrium state. When α is 1, the volatilities of the two components are equal, indicating that the two components cannot be separated by adsorption distillation. The larger α is and the higher the value of α, the easier it is to separate the two components by adsorption distillation.

[0030] Hereinafter, the present invention will be further described with reference to the drawings.

[0031] In FIG. 1, the C8 aromatic mixture from pipeline 1 is introduced into the central part of the adsorption distillation column 3. The composite adsorbent is introduced into the upper part of the adsorption distillation column from pipeline 2. The C8 aromatics perform adsorption and distillation by countercurrent contact with the composite adsorbent inside the column. The xylene in the C8 aromatics is adsorbed by the xylene adsorbent. Ethylbenzene is distilled to the top of the column and discharged from pipeline 7 at the top of the column, and condensed to obtain an ethylbenzene product. The composite adsorbent adsorbed with xylene is discharged from the bottom of the adsorption distillation column and enters the central part of the distillation desorption column 4 through pipeline 5. Xylene is desorbed from the composite adsorbent by distillation, and the desorption and regeneration of the xylene adsorbent are realized. The desorbed xylene is discharged from the top pipeline 8 of the distillation desorption column and condensed to obtain xylene. The regenerated composite adsorbent is discharged from the bottom of the distillation desorption column and returns to the adsorption distillation column via pipeline 6 and pipeline 2 for reuse. The said xylene basically does not contain ethylbenzene and can be used as an isomerization raw material for producing p-xylene.

[0032] Hereinafter, the present invention will be further described through examples, but the present invention is not limited thereto.

[0033] In the examples and comparative examples, the method for measuring the relative volatility of each composition of C8 arenes is as follows: The sample to be measured is added to the headspace sampler of Agilent 7694, left for a certain period of time, and when vapor-liquid equilibrium is reached, the gas-phase and liquid-phase components of the sampler are measured using Agilent 7890 chromatography, and the relative volatility of the components is calculated by formula (1).

[0034] Example 1 Ethylbenzene, p-xylene, o-xylene, and m-xylene were mixed at the same mass ratio to prepare a C8 arene mixture as the feedstock oil. The content of ethylbenzene in the feedstock oil was 25% by mass. NaY molecular sieve powder with a crystal particle size of 0.2 - 1 micron was used as the xylene adsorbent, and n-tetradecane was used as the carrier liquid. The xylene adsorbent was mixed with the carrier liquid to prepare a composite adsorbent with a xylene adsorbent content of 20% by mass and a carrier liquid content of 80% by mass.

[0035] The composite adsorbent and the feedstock oil were added to the headspace sampler. Here, the mass ratio of carrier liquid / xylene adsorbent / feedstock oil was 8:2:1, and the mass ratio of the composite adsorbent to the feedstock oil was 10:1. Also, it was left standing at 80 °C for 45 minutes to achieve vapor-liquid equilibrium. For composition analysis, the gas phase and the liquid phase were sampled respectively. The measured relative volatility of ethylbenzene with respect to each xylene isomer of the feedstock oil after the addition of the composite adsorbent is shown in Table 1.

[0036] Example 2 The relative volatility of ethylbenzene with respect to each xylene isomer of the feedstock oil after the addition of the composite adsorbent was measured in the same manner as in the method of Example 1, except that the mass ratio of the carrier liquid / xylene adsorbent / feedstock oil used was 8:3:1, and the mass ratio of the composite adsorbent to the feedstock oil was 11:1. The measurement results are shown in Table 1.

[0037] Example 3 Except that the mass ratio of the carrier liquid / xylene adsorbent / feedstock oil used was 8:4:1 and the mass ratio of the composite adsorbent to the feedstock oil was 12:1, in the same manner as in Example 1, the relative volatility of ethylbenzene with respect to each xylene isomer in the feedstock oil after the addition of the composite adsorbent was measured. The measurement results are shown in Table 1.

[0038] Example 4 Except that the mass ratio of the carrier liquid / xylene adsorbent / feedstock oil used was 13:2:1 and the mass ratio of the composite adsorbent to the feedstock oil was 15:1, in the same manner as in Example 1, the relative volatility of ethylbenzene with respect to each xylene isomer in the feedstock oil after the addition of the composite adsorbent was measured. The measurement results are shown in Table 1.

[0039] Example 5 Except that the mass ratio of the carrier liquid / xylene adsorbent / feedstock oil used was 18:2:1 and the mass ratio of the composite adsorbent to the feedstock oil was 20:1, in the same manner as in Example 1, the relative volatility of ethylbenzene with respect to each xylene isomer in the feedstock oil after the addition of the composite adsorbent was measured. The measurement results are shown in Table 1.

[0040] Example 6 Except that the carrier liquid used was n-undecane, in the same manner as in Example 1, the relative volatility of ethylbenzene with respect to each xylene isomer in the feedstock oil after the addition of the composite adsorbent was measured. The measurement results are shown in Table 1.

[0041] Example 7 Except that the carrier liquid used was n-hexadecane, in the same manner as in Example 1, the relative volatility of ethylbenzene with respect to each xylene isomer in the feedstock oil after the addition of the composite adsorbent was measured. The measurement results are shown in Table 1.

[0042] Example 8 Except that the carrier liquid used was diphenylmethane, in the same manner as in Example 1, the relative volatility of ethylbenzene with respect to each xylene isomer in the feedstock oil after the addition of the composite adsorbent was measured. The measurement results are shown in Table 1.

[0043] Examples 9 - 10 The relative volatility of ethylbenzene with respect to each xylene isomer in the feedstock oil after addition of the composite adsorbent was measured in the same manner as in Example 1, except that the carrier liquids used were butyldecalin and decalin, respectively. The measurement results are shown in Table 1.

[0044] Example 11 The relative volatility of ethylbenzene with respect to each xylene isomer in the feedstock oil after addition of the composite adsorbent was measured in the same manner as in Example 1, except that the mass ratio of ethylbenzene / p - xylene / o - xylene / m - xylene in the feedstock oil used was 1:2:1:1 and the ethylbenzene content of the feedstock oil was 20% by mass. The measurement results are shown in Table 1.

[0045] Example 12 The relative volatility of ethylbenzene with respect to each xylene isomer in the feedstock oil after addition of the composite adsorbent was measured in the same manner as in Example 1, except that the mass ratio of ethylbenzene:p - xylene:o - xylene:m - xylene in the feedstock oil used was 2:1:1:1 and the ethylbenzene content of the feedstock oil was 40% by mass. The measurement results are shown in Table 1.

[0046] [Table 1]

[0047] Comparative Example 1 The relative volatility of ethylbenzene with respect to each xylene isomer in the feedstock oil was measured in the same manner as in Example 1, except that no composite adsorbent was used. The measurement results are shown in Table 1.

[0048] Comparative Example 2 Except for not using the composite adsorbent and the mass ratio of ethylbenzene:p-xylene:o-xylene:m-xylene in the raw material oil used being 1:2:1:1, in the same manner as in the method of Example 1, the relative volatility of ethylbenzene with respect to each xylene isomer in the raw material oil was measured. The measurement results are shown in Table 1.

[0049] Comparative Example 3 Except for not using the composite adsorbent and the mass ratio of ethylbenzene:p-xylene:o-xylene:m-xylene in the raw material oil used being 2:1:1:1, in the same manner as in the method of Example 1, the relative volatility of ethylbenzene with respect to each xylene isomer in the raw material oil was measured. The measurement results are shown in Table 1.

[0050] Comparative Example 4 Only n-tetradecane was added to the raw material oil. Except for the mass ratio of n-tetradecane to the raw material oil being 8:1, in the same manner as in the method of Example 1, the relative volatility of ethylbenzene with respect to each xylene isomer in the raw material oil was measured. The measurement results are shown in Table 1.

[0051] As can be seen from Table 1, by using the composite adsorbent of the present invention, the relative volatility of ethylbenzene with respect to each xylene isomer can be significantly increased compared with the method of not using the composite adsorbent or using only the carrier liquid, which indicates that ethylbenzene can be separated from C8 arenes by using the composite adsorbent of the present invention.

[0052] Example 13 Ethylbenzene and xylene in C8 arenes were separated in the flow shown in FIG. 1 using the composite adsorbent and the raw material oil of Example 1. The operating conditions of the adsorption distillation column and the distillation desorption column and the purity of the obtained product are shown in Table 2.

[0053] Comparative Example 5 Ethylbenzene and xylene in the raw material oil of Example 1 were separated using a general distillation column. The operating conditions of the distillation column and the purity of the obtained product are shown in Table 2.

[0054] Comparative Example 6 Ethylbenzene was separated from C8 arenes using an extractive distillation method. The C8 arenes were introduced into the central part of the extractive distillation column, and the extractive solvent was introduced into the upper part of the column. After extractive distillation, ethylbenzene was discharged from the top of the column. The rich solvent rich in xylene was discharged from the bottom of the column and put into a solvent recovery column. After distillation, xylene was discharged from the top of the column, and the dilute solvent was discharged from the bottom of the column and returned to the extractive distillation column. 1,2,4-Trichlorobenzene was used as the extractive solvent. The C8 arene feedstock oil was formulated by the method of Example 1. The operating conditions of the extractive distillation column and the solvent recovery column and the purity of the obtained product are shown in Table 2.

[0055] [Table 2]

[0056] Example 14 Using the composite adsorbent of Example 1, the feedstock oil was the reformed product C8 fraction, and the mass ratio of ethylbenzene:p-xylene:m-xylene:o-xylene was 18:19:39:24. Ethylbenzene and xylene in the C8 fraction were separated by the flow shown in Figure 1. The operating conditions of the adsorption distillation column and the distillation desorption column and the purity of the obtained product are shown in Table 3.

[0057] Comparative Example 7 Ethylbenzene and xylene in the feedstock oil of Example 14 were separated using a general distillation column. The operating conditions of the distillation column and the purity of the obtained product are shown in Table 3.

[0058] [Table 3]

[0059] Example 15 Using the composite adsorbent of Example 1, the feedstock oil was the C8 fraction of ethylene cracking gasoline, and the mass ratio of ethylbenzene:p-xylene:m-xylene:o-xylene was 52:10:23:15. The ethylbenzene and xylene in the C8 fraction were separated in the flow shown in Figure 1. Table 4 shows the operating conditions of the adsorption distillation column and the distillation desorption column and the purity of the obtained products.

[0060] Comparative Example 8 The ethylbenzene and xylene in the feedstock oil of Example 15 were separated using a normal distillation column. Table 4 shows the operating conditions of the distillation column and the purity of the obtained products.

[0061]

Table 4

[0062] As can be seen from Tables 2 to 4, compared with separating ethylbenzene using a general distillation column or extractive distillation alone, separating ethylbenzene from C8 arenes using the adsorption distillation of the present invention can significantly reduce the energy consumption and improve the separation efficiency of ethylbenzene and xylene.

Claims

1. It contains 1 to 50% by mass of a xylene adsorbent and 50 to 99% by mass of a carrier liquid. The carrier liquid is selected from one or two of alkanes, aryl-substituted alkanes, decalin, and alkyl-substituted decalin. The alkane is a C10-C24 n-alkane, the aryl-substituted alkane is a C13-C16 diphenylalkane, the alkyl of the alkyl-substituted decalin is a C1-C12 alkyl, and the number of substituted alkyls is 1 to 4. The xylene adsorbent is a Y zeolite having Group IA and / or Group IIA metal ions occupying cation sites. The particle size of the crystal particles of the Y zeolite is 0.1 to 2 microns. For separating ethylbenzene from C ８ A composite adsorbent for separating ethylbenzene from arenes by adsorption distillation.

2. The composite adsorbent according to claim 1, characterized in that it contains 5 to 35% by mass of a xylene adsorbent and 65 to 95% by mass of a carrier liquid.

3. The composite adsorbent according to claim 1, characterized in that the xylene adsorbent is a NaY zeolite.

4. The alkane is C １１ -C ２０ n-alkane, and the alkyl of the alkyl-substituted decalin is C ３ -C １０ alkyl. The composite adsorbent according to claim 1 is characterized in that.

5. C ８Introduce the arenes mixture into the central part of the adsorption distillation column (3), introduce the composite adsorbent according to claim 1 into the upper part of the adsorption distillation column (3), after adsorption distillation, discharge ethylbenzene from the top of the adsorption distillation column, discharge the composite adsorbent rich in xylene from the bottom of the column, put this into the central part of the distillation desorption column (4), after distillation desorption, discharge the mixed xylene from the upper part of the column, obtain the regenerated composite adsorbent at the bottom of the column, and return it to the upper part of the adsorption distillation column for reuse, a method for separating ethylbenzene by adsorption distillation.

6. The top pressure of the adsorption distillation column is 0.01 to 0.2 MPa, the theoretical number of trays is 30 to 100, the composite adsorbent enters the column at a temperature of 90 to 130 °C, and the bottom temperature of the column is 140 to 250 °C. The method according to claim 5, characterized in that.

7. The mass ratio of the xylene adsorbent of the composite adsorbent entering the adsorption distillation column to the C ８ The mass ratio to the arenes mixture is 1.5 to 6, the mass ratio of the carrier liquid to the xylene adsorbent is 1.5 to 20, and the reflux ratio is 1 to 15. The method according to claim 6, characterized in that.

8. The top pressure of the distillation desorption column is 0.01 to 0.15 MPa, the theoretical number of trays is 20 to 50, and the bottom temperature of the column is 160 to 280 °C. The method according to claim 5, characterized in that.

9. The reflux ratio of the distillation desorption column is 0.3 to 3. The method according to claim 8, characterized in that.

10. C ８ The content of ethylbenzene in the arenes mixture is 10 to 85% by mass. The method according to claim 5, characterized in that.

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