JP2007203148A - Catalyst composition for conversion reaction of aromatic hydrocarbon, and conversion process of aromatic hydrocarbon using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst composition for conversion reaction of aromatic hydrocarbons which is capable of recovering benzene with high quality and to provide a conversion process of aromatic hydrocarbons using the same. <P>SOLUTION: The catalyst composition for the conversion reaction of aromatic hydrocarbons is characterized by containing 40-90 pts.wt. of mordenite and 60-10 pts.wt. of an inorganic oxide per 100 pts.wt. based on the total weight of mordenite and the inorganic oxide, 0.05-2 wt.% of rhenium in the catalyst composition and 0.05 to 5 wt.% of silver in the catalyst composition. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a catalyst composition for conversion reaction of aromatic hydrocarbons and an aromatic hydrocarbon conversion method using the same. In particular, aromatics that produce aromatic hydrocarbons such as xylene and benzene from aromatic hydrocarbon raw materials containing C9 alkyl aromatic hydrocarbons by at least one of disproportionation, transalkylation, and dealkylation reactions The present invention relates to a catalyst composition for a conversion reaction of a compound and a method for converting an aromatic hydrocarbon using the same.

  Aromatic hydrocarbon disproportionation and / or transalkylation reactions such as the production of xylene and benzene by disproportionation of toluene and the production of xylene by transalkylation of toluene and trimethylbenzene are industrially important reactions, Many catalyst systems have been proposed in the past. Recently, crystalline aluminosilicate zeolites such as faujasite and mordenite have been found to be effective catalysts. In particular, mordenite has a high disproportionation activity of toluene (for example, patent documents). 1).

  However, mordenite alone is not sufficient in both activity and catalyst life, and it is disclosed that rhenium is combined with mordenite in order to improve activity and improve the catalyst life (for example, see Patent Document 2). Moreover, the high conversion activity of toluene, the low catalyst deactivation rate, and the reduction | decrease of a non-aromatic by-product are disclosed by making mordenite contain nickel (for example, refer patent document 3).

  On the other hand, it is disclosed that xylene can be efficiently produced by a transalkylation reaction from an aromatic hydrocarbon-containing raw material containing C9 aromatic hydrocarbon by combining mordenite and a hydrogenation active metal (for example, Patent Document 4). reference).

Benzene by-produced by the reaction is also an industrially important raw material such as ethylbenzene synthesis or cyclohexane synthesis. High purity is required for benzene for use as a crude material for ethylbenzene synthesis or cyclohexane synthesis. The benzene-containing aromatic hydrocarbon obtained by the reaction usually separates benzene by distillation separation. However, cyclohexane (boiling point 80.7 ° C.) having a boiling point close to benzene (boiling point 80.1 ° C.) and fats such as methyl-cyclopentane, dimethyl-cyclopentane, and methyl-cyclohexane, which are azeotropic components with benzene. If a ring compound is present, separation from benzene becomes difficult by the distillation method, and the purity of the benzene decreases. The presence of the hydrogenation active metal hydrogenates the aromatic nuclei of the aromatic hydrocarbons in the feedstock, increasing these components that are difficult to separate from benzene by distillation, reducing benzene purity.
Japanese Patent Publication No. 47-46051 (Example 1) Japanese Examined Patent Publication No. 62-45849 (Example 1) Japanese Patent Application Laid-Open No. 5-22184 (column 8, lines 6 to 11) JP-A-11-70334 (Example 7)

  An object of the present invention is to provide a catalyst composition for the conversion reaction of an aromatic hydrocarbon capable of recovering benzene having a high purity and a method for converting an aromatic hydrocarbon using the same.

  In addition, when an aromatic hydrocarbon-containing raw material containing ethyltoluene is used and the conversion reaction is performed in the presence of hydrogen, the hydrocracking reaction of aromatic nuclei is suppressed, xylene is efficiently produced, and high-purity benzene is produced. The present invention provides a catalyst composition for conversion reaction of aromatic hydrocarbons to be produced and a method for converting aromatic hydrocarbons using the same.

  That is, as a useful method for producing xylene and benzene, there is a method in which a raw material containing toluene is subjected to a disproportionation reaction and / or a transalkylation reaction. However, toluene has a utility value as a part of a gasoline base material for increasing the octane number. On the other hand, C9 alkyl aromatic hydrocarbons have little industrial utility value and are often used as fuel. Ethyltoluene contained in C9 alkyl aromatic hydrocarbons is converted into toluene by dealkylation reaction, and industrially useful xylene and / or benzene is obtained by disproportionation reaction with two toluene molecules or transalkylation reaction with toluene and trimethylbenzene. Can be manufactured. When dehydrating ethyltoluene and converting it to toluene, hydrodealkylation with hydrogenated active metal in the presence of hydrogen eliminates the constraint of thermodynamic equilibrium, and theoretically close to 100% of toluene. Can be converted. However, in the presence of hydrogen, the hydrogenated active metal causes a part of the aromatic hydrocarbon in the feedstock to cause a nuclear hydrogenation reaction, producing an alicyclic compound and lowering the benzene purity.

  Therefore, the present invention provides an aromatic hydrocarbon conversion catalyst composition capable of recovering high-purity benzene while maintaining a high xylene yield even in the above case, and a conversion method using the same Is an issue.

  In order to solve the above-mentioned problems, the present inventors have intensively studied. A catalyst composition for conversion reaction of an aromatic hydrocarbon, characterized in that rhenium is contained in the catalyst composition in an amount of 0.05 to 2% by weight, and silver is contained in the catalyst composition in an amount of 0.05 to 5% by weight. The present inventors have found that high-purity benzene can be produced by suppressing the hydrogenolysis reaction to aromatic nuclei and efficiently producing xylene.

  According to the present invention, xylene can be produced efficiently and high-purity benzene can be produced.

  The zeolite used in the present invention is mordenite. The mordenite is preferably a mordenite having a silica / alumina molar ratio of 12 to 25, more preferably 15 to 20. In order to obtain mordenite having a silica / alumina molar ratio of 12 to 25, there are a method of dealumination of mordenite having a low silica / alumina molar ratio by acid extraction and a method of directly synthesizing mordenite having a silica / alumina molar ratio of 12 to 25. Directly synthesized synthetic mordenite is preferably used. A method for synthesizing mordenite is disclosed, for example, in American Mineralist 57 卷 (1972), pages 1146 to 1151, Japanese Examined Patent Publication No. 63-51969, and Japanese Examined Patent Publication No. 2-31006.

  Inorganic oxides are essential to disperse and support zeolite and rhenium. Examples of the inorganic oxide include alumina, silica / alumina, silica, titania, magnesia and clay. Of these, alumina is particularly preferable. Known aluminas include boehmite, boehmite gel, dibsite, vialite, norstrandite, diaspore, amorphous alumina gel, and the like. Any alumina can be used, but boehmite is preferred. Examples of clays include natural or refined clays such as montmorillonite, kaolin, sepiolite, and acid clay.

  The blending ratio of mordenite and inorganic oxide is 40 to 90 parts by weight of mordenite, 60 to 10 parts by weight of inorganic oxide, 40 to 60 parts by weight of mordenite, and inorganic when the total of both is 100 parts by weight. It is preferred that the oxide is 60 to 40 parts by weight.

  The catalyst composition of the present invention is usually used after being molded. Examples of the molding method include a compression molding method, a rolling method, and an extrusion method, and the extrusion method is more preferable. In the extrusion method, a binder is used to bind the synthetic zeolite powder and the inorganic oxide. Examples of the binder include alumina sol, alumina gel, bentonite, and kaolin. In particular, alumina sol and alumina gel are preferable. These binders also function as inorganic oxides in which zeolite is dispersed. Accordingly, these binders are also included in an anhydrous state as inorganic oxides in the ratio of zeolite to inorganic oxide in the catalyst composition. If necessary, a surfactant such as sodium dodecylbenzenesulfonate, span or twin is added as a molding aid and kneaded. If necessary, a machine such as a kneader is used. The kneaded material is extruded from the screen. Industrially, for example, an extruder called an extruder is used. The kneaded product extruded from the screen becomes a noodle-like product. The size of the molded body is determined by the screen diameter to be used. The screen diameter is preferably 0.2 to 2.0 mmφ. The noodle-like molded body extruded from the screen is preferably treated with a malmerizer to round off the corners. The molded body molded in this way is dried at 50 to 250 ° C. After drying, in order to improve the molding strength, baking is performed at 250 to 600 ° C, preferably 350 to 600 ° C.

In the molded body thus produced, hydrogen ions and / or ammonium ions which are hydrogen ion precursors are introduced by ion exchange in order to develop solid acidity. Ion exchange may be performed simultaneously or separately. As a method for imparting solid acidity, a compound directly containing an acid (for example, HCl, HNO ₃ , H ₃ PO _4, etc.), a method of introducing hydrogen ions into the ion exchange site of zeolite, or a compound containing ammonium ions (For example, NH ₄ Cl, NH ₄ NO ₃ , (NH ₄ ) ₂ SO _4, etc.), ion exchange treatment is performed, NH ₄ ions are introduced into the ion exchange site of the zeolite, and then hydrogen ions are dried and calcined. However, the former is preferably subjected to ion exchange treatment with the latter, that is, a compound containing ammonium ions which are hydrogen ion precursors, because the zeolite structure may be destroyed. The ion exchange treatment may be either a distribution method or a batch method. The temperature is from room temperature to 95 ° C., and preferably from 50 to 85 ° C. in order to increase the ion exchange rate. The concentration of the aqueous ammonium salt solution used for ion exchange is 1 to 15% by weight, preferably 2 to 10% by weight.

  For the purpose of improving the catalytic activity, it is also preferable to treat the catalyst with an aqueous solution containing an organic acid such as tartaric acid, oxalic acid, succinic acid, malic acid or the like. The treatment with the organic acid aqueous solution is performed at room temperature to 95 ° C., preferably at room temperature to 50 ° C. The organic acid concentration in the organic acid aqueous solution is 1 to 15% by weight, preferably 2 to 10% by weight.

  Next, the silver contained in the conversion reaction catalyst composition of the present invention will be described. Silver is introduced by silver ion exchange into mordenite. The silver ion may be any compound that is soluble in water, but nitrate is preferably used. Silver ion exchange may be performed simultaneously with ammonium ion exchange, or may be performed separately. The ion exchange treatment is usually carried out with an aqueous solution by a batch method or a distribution method. The treatment temperature is usually from room temperature to 100 ° C. A preferable loading amount of silver is 0.05 to 5% by weight, more preferably 0.5 to 4% by weight in the catalyst composition.

  Rhenium may exist in a metal form or in the form of an oxide, sulfide, selenide or the like, and those that can be particularly preferably used as the rhenium component include perrhenic acid and ammonium perrhenate. The following method is most preferable as an embodiment for supporting the rhenium component. A preferable rhenium loading is 0.01 to 2% by weight, more preferably 0.05 to 1% by weight in the catalyst composition. Mordenite and inorganic oxide are uniformly mixed, molded, dried and fired. Next, a method in which hydrogen ions, ammonium ions, and silver ions are introduced into mordenite and then impregnated with an aqueous solution containing rhenium is preferable. The catalyst carrying rhenium is subsequently dried and calcined. Ammonium-type zeolite becomes hydrogen-type mordenite during the calcination process. Preferable firing conditions are 300 to 650 ° C. in an oxygen-containing atmosphere.

  Using the catalyst composition in question, an aromatic hydrocarbon, preferably an aromatic hydrocarbon containing a C9 alkyl aromatic hydrocarbon such as ethyltoluene, trimethylbenzene, etc., is fed (sometimes referred to as “feedstock oil”). To produce xylene and / or benzene from the feedstock through at least one of a conversion reaction, specifically a disproportionation reaction, a transalkylation reaction, a dealkylation reaction. The contact is preferably performed in the presence of hydrogen.

As mentioned above, when performing the said reaction using the catalyst composition prepared as mentioned above, it can carry out according to conventionally well-known various reaction operation. The reaction system is preferably a fixed bed reaction system and is used under the following reaction conditions. That is, the reaction operating temperature is 300 to 600 ° C, preferably 350 to 550 ° C. The reaction operation pressure is from atmospheric pressure to 10 MPa-G, preferably 0.3 to 5 MPa-G. The gas hourly space velocity (WHSV) representing the contact time of the reaction is 0.1 to 20 hr ⁻¹ , preferably 0.5 to 10 hr ⁻¹ . The ratio of hydrogen to feedstock oil is 0.5 to 10 molar ratio, preferably 1 to 5 molar ratio. More preferably, the feedstock oil is contacted with the catalyst in the gas phase.

The feedstock oil is preferably a C9 aromatic hydrocarbon such as ethyltoluene or trimethylbenzene as an aromatic hydrocarbon or one containing it, and particularly preferably contains at least 5% by weight of ethyltoluene for xylene production. This is because ethyltoluene becomes toluene by hydrodealkylation reaction on the catalyst composition of the present invention, and the toluene and trimethylbenzene generate xylene by transalkylation reaction. Also, the feedstock oil tends to azeotrope with benzene on the catalyst composition according to the present invention, and cyclohexane, methyl-cyclopentane, dimethyl-cyclopentane, and methyl-cyclohexane, which are difficult to separate from benzene by distillation, are reduced. . For this reason, when the reaction product is separated and recovered by a distillation method, the purity of the obtained benzene can be improved. Here, benzene purity is defined as follows.
Benzene purity (wt%)
= ([Benzene]) / ([benzene] + [methyl-cyclopentane] + [dimethyl-cyclopentane] + [cyclohexane] + [methyl-cyclohexane]) × 100
(In the formula, [] represents the weight of the substance in [].)

  In the conversion method of the present invention, it is one of the embodiments of the present invention that toluene and benzene are allowed to coexist in the feedstock. For example, a composition containing benzene and one or more alicyclic compounds selected from methyl-cyclopentane, dimethyl-cyclopentane, cyclohexane, and methyl-cyclohexane, for example, some of the above obtained by distillation separation of benzene obtained in the present invention It is also one embodiment that the composition of benzene containing the alicyclic compound, partly or entirely recycled to the feedstock oil, and again brought into contact with the catalyst to further improve the benzene purity. In addition, as a composition containing the said alicyclic compound and benzene, the composition collect | recovered by other reaction may be sufficient.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

(Synthesis of mordenite type zeolite)
Solid caustic soda (NaOH content 96.0% by weight, H ₂ O content 4.0% by weight, Kirk Corporation) 21.3 grams, tartaric acid powder (tartaric acid content 99.7% by weight, H ₂ O content 0.3% by weight) , Kirk Co., Ltd.) 21.3 grams was dissolved in 586.8 grams of distilled water. To this solution was added 29.2 grams of sodium aluminate solution (Al ₂ O ₃ content 18.5 wt%, NaOH content 26.1 wt%, H ₂ O content 55.4 wt%, Sumitomo Chemical Co., Ltd.) A uniform solution was obtained. Hydrous silicic acid (SiO ₂ content 91.6 wt%, Al ₂ O ₃ content 0.33 wt%, NaOH content 0.27 wt%, Nipsil VN-3, Nippon Silica Industry Co., Ltd.) 111.5 Grams were added slowly with stirring to prepare a uniform slurry aqueous reaction mixture. The composition ratio (molar ratio) of this reaction mixture was as follows.
SiO ₂ / Al ₂ O ₃ 30
OH ⁻ / SiO ₂ 0.5
A / Al ₂ O ₃ 2.5 (A: tartrate)
H ₂ O / SiO ₂ 20

  The reaction mixture was sealed in a 1 L autoclave and then reacted at 160 ° C. for 72 hours while stirring at 250 rpm. After completion of the reaction, washing with distilled water 5 times and filtration were repeated, followed by drying at about 120 ° C. overnight. As a result of measuring the obtained product with an X-ray diffractometer using Cu tube and Kα ray, it was found to be mordenite type zeolite.

  The silica / alumina molar ratio of this mordenite-type zeolite was 18.6 as a result of fluorescent X-ray diffraction analysis.

  As a result of FE-SEM observation at a magnification of 10,000, the crystallite size was mainly about 0.5 microns.

(Preparation of catalyst)
Example 1 (Catalyst 1)
30 g of mordenite-type zeolite powder on the basis of absolute dryness (calculated from the loss on ignition when calcined at 500 ° C. for 20 minutes), hydrous alumina (SASOL, Al ₂ O ₃ content 75% by weight) 26.7 g (Al ₂ O ₃ (20 grams) and alumina sol (Al ₂ O ₃ content 10 wt%, Nissan Chemical Industries, Ltd.) 75 grams (7.5 grams as Al ₂ O ₃ ) were added and mixed well. Then, it put into 120 degreeC dryer and dried until it became clay-like water | moisture content. The kneaded product was extruded through a screen having a 1.2 mmφ hole. The extrudate was dried at 120 ° C. overnight, then gradually heated from 350 ° C. to 500 ° C. and fired at 500 ° C. for 2 hours. The ratio of mordenite to inorganic oxide (aluminum) was 52 parts by weight of mordenite and 48 parts by weight of inorganic oxide. 30 grams of the baked mordenite molded body was taken, placed in an aqueous solution in which 4.5 grams of ammonium chloride (Aldrich) was dissolved in 90 ml of distilled water, and subjected to ion exchange treatment at 80 ° C. for 1 hour with occasional stirring. After the treatment, the aqueous solution was removed, washed once with distilled water, and filtered. Again, it was put into an aqueous solution in which 4.5 g of ammonium chloride was dissolved in 90 ml of distilled water, and subjected to ion exchange treatment with occasional stirring at 80 ° C. for 1 hour, followed by washing with water / filtration. This operation was repeated a total of 5 times. After the ion exchange treatment, washing with distilled water and filtration were repeated 5 times. Subsequently, it was immersed in 90 ml of an aqueous solution containing 3 grams of tartaric acid (Tokyo Kasei Kogyo Co., Ltd.) and left to stir occasionally for 2 hours at room temperature. Thereafter, washing with distilled water and filtration were repeated 5 times. Silver nitrate (Tokyo Chemical Industry Co., Ltd.) (1.42 grams) was immersed in an aqueous solution dissolved in 90 ml of distilled water, and allowed to stand at room temperature for 2 hours with occasional stirring. Thereafter, washing with distilled water and filtration were repeated 5 times. It was immersed at room temperature in 45 ml of a perrhenic acid aqueous solution (Rare Product Metal Co., Ltd.) containing 120 milligrams of Re and stirred for 2 hours with stirring every 30 minutes. Then, the liquid was cut off and dried at 120 ° C. overnight. After drying, it was baked in air at 540 ° C. for 2 hours. This catalyst is referred to as “catalyst 1”. Further, the silver concentration in the catalyst 1 was 2.8% by weight from fluorescent X-ray analysis. As a result of measuring the amount of rhenium supported by ICP emission spectrometry, it was 0.28% by weight as Re metal.

Comparative Example 1 (Catalyst 2)
Take 30 grams of molded mordenite molded and calcined in the same manner as Catalyst 1, put it in an aqueous solution of 4.5 grams of ammonium chloride (Aldrich) in 90 ml of distilled water and stir occasionally at 80 ° C. for 1 hour. Ion exchange treatment was performed. After the treatment, the aqueous solution was removed, washed once with distilled water, and filtered. Again, it was put into an aqueous solution in which 4.5 g of ammonium chloride was dissolved in 90 ml of distilled water, and subjected to ion exchange treatment with occasional stirring at 80 ° C. for 1 hour, followed by washing with water / filtration. This operation was repeated a total of 5 times. After the ion exchange treatment, washing with distilled water and filtration were repeated 5 times. Subsequently, it was immersed in 90 ml of an aqueous solution containing 3 grams of tartaric acid (Tokyo Kasei Kogyo Co., Ltd.) and left to stir occasionally for 2 hours at room temperature. Thereafter, washing with distilled water and filtration were repeated 5 times. It was immersed at room temperature in 45 ml of a perrhenic acid aqueous solution (Rare Product Metal Co., Ltd.) containing 120 milligrams of Re and stirred for 2 hours with stirring every 30 minutes. Then, the liquid was cut off and dried at 120 ° C. overnight. After drying, it was baked in air at 540 ° C. for 2 hours. This catalyst is referred to as “catalyst 2”. The amount of rhenium supported in the catalyst 2 was 0.30% by weight as Re metal as measured by ICP emission spectrometry.

Comparative Example 2 (Catalyst 3)
Take 30 grams of molded mordenite molded and calcined in the same manner as Catalyst 1, put it in an aqueous solution of 4.5 grams of ammonium chloride (Aldrich) in 90 ml of distilled water and stir occasionally at 80 ° C. for 1 hour. Ion exchange treatment was performed. After the treatment, the aqueous solution was removed, washed once with distilled water, and filtered. Again, it was put into an aqueous solution in which 4.5 g of ammonium chloride was dissolved in 90 ml of distilled water, and subjected to ion exchange treatment with occasional stirring at 80 ° C. for 1 hour, followed by washing with water / filtration. This operation was repeated a total of 5 times. After the ion exchange treatment, washing with distilled water and filtration were repeated 5 times. Subsequently, it was immersed in 90 ml of an aqueous solution containing 3 grams of tartaric acid (Tokyo Kasei Kogyo Co., Ltd.) and left to stir occasionally for 2 hours at room temperature. Thereafter, washing with distilled water and filtration were repeated 5 times. 2.84 grams of silver nitrate (Tokyo Chemical Industry Co., Ltd.) was immersed in an aqueous solution dissolved in 90 ml of distilled water and allowed to stand at room temperature for 2 hours with occasional stirring. Thereafter, washing with distilled water and filtration were repeated 5 times. It was immersed at room temperature in 45 ml of a perrhenic acid aqueous solution (Rare Product Metal Co., Ltd.) containing 120 milligrams of Re and stirred for 2 hours with stirring every 30 minutes. Then, the liquid was cut off and dried at 120 ° C. overnight. After drying, it was baked in air at 540 ° C. for 2 hours. This catalyst is referred to as “catalyst 3”. The silver concentration in the catalyst 3 was 5.6% by weight from fluorescent X-ray analysis. The amount of rhenium supported was 0.29% by weight as Re metal as measured by ICP emission spectrometry.

Comparative Example 3 (Catalyst 4)
Take 30 grams of molded mordenite molded and calcined in the same manner as Catalyst 1, put it in an aqueous solution of 4.5 grams of ammonium chloride (Aldrich) in 90 ml of distilled water and stir occasionally at 80 ° C. for 1 hour. Ion exchange treatment was performed. After the treatment, the aqueous solution was removed, washed once with distilled water, and filtered. Again, it was put into an aqueous solution in which 4.5 g of ammonium chloride was dissolved in 90 ml of distilled water, and subjected to ion exchange treatment with occasional stirring at 80 ° C. for 1 hour, followed by washing with water / filtration. This operation was repeated a total of 5 times. After the ion exchange treatment, washing with distilled water and filtration were repeated 5 times. Subsequently, it was immersed in 90 ml of an aqueous solution containing 3 grams of tartaric acid (Tokyo Kasei Kogyo Co., Ltd.) and left to stir occasionally for 2 hours at room temperature. Thereafter, washing with distilled water and filtration were repeated 5 times. 6.0 grams of barium nitrate (Katayama Chemical Co., Ltd.) was immersed in an aqueous solution dissolved in 90 ml of distilled water, and allowed to stand at 80 ° C. for 2 hours with occasional stirring. Thereafter, washing with distilled water and filtration were repeated 5 times. It was immersed at room temperature in 45 ml of a perrhenic acid aqueous solution (Rare Product Metal Co., Ltd.) containing 120 milligrams of Re and stirred for 2 hours with stirring every 30 minutes. Then, the liquid was cut off and dried at 120 ° C. overnight. After drying, it was baked in air at 540 ° C. for 2 hours. This catalyst is referred to as “catalyst 4”. The barium concentration in the catalyst 4 was 1.9% by weight as Ba as a result of fluorescent X-ray analysis. The amount of rhenium supported was 0.29% by weight as Re metal as measured by ICP emission spectrometry.

Example 2
6.92 g of catalyst 1 was taken and charged into a reaction tube. A feedstock having the composition shown in Table 1 was fed at 14.55 g / h and hydrogen at 12.12 L / h, and reacted at a reaction pressure of 2.64 MPa-G and a reaction temperature of 380 ° C. The reaction product was analyzed 124 hours after the reaction temperature reached 380 ° C. The analysis used three gas chromatographs with a hydrogen flame detector. The separation column is as follows.

(1) Gas components (components from methane to n-butane in the gas):
Filler “Unipak S” (“Unipak S”) 100-150 mesh,
Column made of stainless steel 4m length 3mmφ inside diameter
N ₂ 1.65 kg / cm ² -G
80 ℃

(2) Component having boiling point around benzene in liquid component (from methane dissolved in liquid to n-butane and liquid component 2-methyl-butane to benzene component):
Filler 25% polyethylene glycol 20M / carrier "Simalite" 60-80 mesh,
Column made of stainless steel 12m long, 3mm inside diameter
N ₂ 2.25 kg / cm ² -G
The temperature was increased from 68 ° C. to 180 ° C. at a rate of temperature increase of 2 ° C./min.

(3) Components with boiling points higher than liquid components benzene (from benzene to heavy-end components):
Spellco Wax Fused Silica Capillary Length 60m Inner Diameter 0.32mmφ Film Thickness 0.5μm
He linear velocity: 23 cm / sec. Temperature: From 67 ° C. to 1 ° C./min, from 80 ° C. to 2 ° C./min.

  The results are shown in Table 1. Xylene was produced at 34.3% by weight.

In Table 1, the purity of benzene is a value determined as follows.
Benzene purity (wt%)
= ([Benzene]) / ([benzene] + [methyl-cyclopentane] + [dimethyl-cyclopentane] + [cyclohexane] + [methyl-cyclohexane]) × 100
(In the formula, [] represents the weight of the substance in [].)

  From Table 1, methyl-cyclopentane, dimethyl-cyclopentane, cyclohexane, and methyl-cyclohexane that were coexisting in the feedstock decreased, and the purity of benzene in the feedstock was 92.51 wt% after the reaction. It can be seen that is improved to 99.10% by weight.

Comparative Example 4
Using catalyst 2, the reaction was carried out in the same manner as in Example 1. The product was analyzed 232 hours after the reaction temperature reached 380 ° C. The results are shown in Table 1. The purity of the produced benzene was 98.50% by weight, which was found to be worse than that of catalyst 1.

Comparative Example 5
The reaction was carried out in the same manner as in Example 1 using the catalyst 3. The product was analyzed 90 hours after the reaction temperature reached 375 ° C. The results are shown in Table 1. The purity of the produced benzene was 98.56% by weight, which was found to be worse than that of catalyst 1.

Comparative Example 6
The reaction was conducted in the same manner as in Example 1 using the catalyst 4. The product was analyzed 121 hours after the reaction temperature reached 391 ° C. The results are shown in Table 1. The purity of the produced benzene was 97.06% by weight, which was found to be worse than that of catalyst 1.

Example 3
About 2 liters of the reaction product liquid obtained in Example 2 was batch-distilled using a distillation tower HP-1000 manufactured by Shibata Kagaku Co., Ltd. And analyzed by gas chromatography. If a benzene component was detected, it was considered that a component having a lower boiling point than benzene could be removed. Then, the distillation was continued. Similarly, when about 10 ml was stored in the upper receiver of the distillation column, the liquid was taken out and analyzed by gas chromatography. When toluene began to be detected, the distillation was stopped. In this way, a component having a boiling point lower than that of benzene was separated, and a component having a boiling point higher than that of benzene was separated to obtain purified benzene. This benzene was mixed with the C9 aromatic hydrocarbon mixture used in Example 1 to provide a feedstock. The composition is shown in Table 2. This feedstock was reacted in the same manner as in Example 1 using Catalyst 1. The reaction product was analyzed 124 hours after the reaction temperature reached 380 ° C. The results are shown in Table 2.

  The benzene purity in the feedstock was 99.00 wt%, but improved to 99.86 wt% after the reaction.

Claims (9)

When the total amount of mordenite and inorganic oxide is 100 parts by weight, mordenite is 40 to 90 parts by weight, inorganic oxide is 60 to 10 parts by weight, rhenium is 0.05 to 2% by weight in the catalyst composition, and silver is A catalyst composition for conversion reaction of an aromatic hydrocarbon, characterized by containing 0.05 to 5% by weight in the catalyst composition. 2. The catalyst composition according to claim 1, wherein the mordenite has a silica / alumina molar ratio of 12 to 25. The catalyst composition according to claim 1 or 2, wherein the inorganic oxide contains at least one selected from alumina, silica / alumina, silica, titania, magnesia and clay. A method for converting an aromatic hydrocarbon, comprising contacting the aromatic hydrocarbon with the catalyst composition for the conversion reaction of an aromatic hydrocarbon according to any one of claims 1 to 3. The method for converting an aromatic hydrocarbon according to claim 4, wherein the raw aromatic hydrocarbon contains at least 5% by weight of ethyltoluene. 6. The method for converting an aromatic hydrocarbon according to claim 4, wherein xylene and / or benzene are produced. An aromatic hydrocarbon containing at least 5% by weight of ethyltoluene is brought into contact with the aromatic hydrocarbon conversion catalyst composition according to any one of claims 1 to 3 and represented by the following formula: A method for converting an aromatic hydrocarbon, characterized by improving purity (% by weight).
Benzene purity (% by weight) = ([benzene]) / ([benzene] + [methyl-cyclopentane] + [dimethyl-cyclopentane] + [cyclohexane] + [methyl-cyclohexane]) × 100
(In the formula, [] represents the weight of the substance in [].) The method for converting an aromatic hydrocarbon according to any one of claims 3 to 7, wherein the aromatic hydrocarbon is brought into contact with the catalyst composition for the conversion reaction of the aromatic hydrocarbon in the presence of hydrogen. Benzene purity is improved by supplying a raw material aromatic hydrocarbon with a composition containing at least one alicyclic compound selected from methyl-cyclopentane, dimethyl-cyclopentane, cyclohexane, and methyl-cyclohexane and benzene. The method for converting an aromatic hydrocarbon according to any one of claims 4 to 8, which is improved.