JPH0827039A - Production of aromatic hydrocarbon and its catalyst - Google Patents

Abstract

PURPOSE:To obtain a catalyst having high activity and high selectivity of an aromatic hydrocarbon and a long catalyst life so as to make an aliphatic hydrocarbon and/or an alicyclic hydrocarbon raw material into an aromatic hydrocarbon. CONSTITUTION:This catalyst comprises crystalline aluminozincosilicate having 14-67 Si/Al atomic ratio, 30-350 Si/Zn atomic ratio, <=0.4wt.% of an alkali metal content, 20-35% ratio of a solid strong acid to a solid acid amount and 0.09-0.16mumol/mg Brphinsted acid obtained by pyridine adsorption measurement by Fourier transfer infrared spectrometry. The catalyst is used to produce a method for producing an aromatic hydrocarbon from a raw material containing at least 50wt.% of a 2-7C aliphatic hydrocarbon and/or alicyclic hydrocarbon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to aromatic compounds obtained by contacting a raw material containing an aliphatic hydrocarbon and / or alicyclic hydrocarbon having 2 to 7 carbon atoms as a main component with a crystalline aluminazine cosilicate as a catalyst. The present invention relates to a method for producing a hydrocarbon and a catalyst thereof.

[0002]

2. Description of the Related Art Many methods for converting aliphatic hydrocarbons and / or alicyclic hydrocarbons into aromatic hydrocarbons for the purpose of reforming petroleum products have been proposed, among which ZSM-5 and A method for converting a hydrocarbon composed of paraffin, olefin and / or naphthene into an aromatic compound with a high selectivity using a so-called zeolite catalyst is already known (Japanese Patent Publication No. 56-42639).

Further, it is disclosed in the above-mentioned patent publication that the yield of aromatic compounds is improved by using zinc-H-ZSM-5 obtained by substituting ZSM-5 type zeolite with zinc cation, or a catalyst supporting zinc. ing.

Further, it is possible to synthesize a zincosilicate having a structure in which aluminum of ZSM-5 is replaced with zinc, and such a zincosilicate catalyst and a platinum-supported zincosilicate catalyst are used for producing aromatic hydrocarbons from lower paraffin hydrocarbons. It is also known to show excellent selectivity (USP Re 29948, JP-A-63-
8342).

Zinc-substituted with such a zinc cation
The H-ZSM-5 catalyst or the zeolite catalyst supporting zinc has a drawback that zinc is lost from the catalyst during the reaction and the catalytic activity decreases with time.
Zinc silicate having a structure in which aluminum is replaced with zinc in 5 has a low acid strength, and it cannot be said that the catalytic activity and the life are sufficient. Therefore, in order to solve the above-mentioned drawbacks, some of the present inventors have Aluminum of ZSM-5 type zeolite (aluminosilicate) is partially replaced with zinc, and a crystalline aluminozine cosilicate catalyst having a specific Si / Al atomic ratio and a specific Si / Zn atomic ratio is used to have 2 to 7 carbon atoms. Proposed a method for producing an aromatic hydrocarbon from the aliphatic hydrocarbon and / or alicyclic hydrocarbon described in JP-A-3-178934.

Further, in order to maintain the activity of the crystalline aluminozine cosilicate catalyst for a long time, an aromatic carbonization using a crystalline aluminozine cosilicate catalyst in which the alkali metal in the catalyst is 0.4% by weight or less. A method for producing hydrogen has been proposed (JP-A-4-95034).
Further, in order to improve the life of the crystalline aluminozincosilicate catalyst, it was proposed to use a catalyst in which the ratio of the solid strong acid amount to the solid acid amount is 20 to 30% (Japanese Patent Laid-Open No. 5-339178). .

[0007]

This catalyst is highly active, has a high aromatic selectivity, and has a long catalyst life as compared with conventional catalysts, and is an excellent catalyst. It was still insufficient to maintain catalytic activity over. The inventors of the present invention studied the catalyst for producing an aromatic hydrocarbon having a long catalyst life by further improving the above crystalline aluminozine cosilicate catalyst, and as a result, these catalysts consist of solid acids such as silica-alumina. However, the catalyst life is not only the amount of solid strong acid in solid acid,
It was found that it is affected by the amount of Bronsted acid in the crystalline aluminozine cosilicate, and found that the catalyst life is significantly improved by adjusting the amount of solid strong acid and the amount of Bronsted acid possessed by the catalyst to a specific range. The invention was reached.

[0008]

According to the present invention, the Si / Al atomic ratio is 14 to 67 and the Si / Zn atomic ratio is 30 to 3.
50, the alkali metal content is 0.4% by weight or less, the ratio of the solid strong acid amount to the solid acid amount is 20 to 35%, and the Bronsted acid amount obtained by pyridine adsorption measurement by Fourier transform infrared spectroscopy is 0.09-0.16 μmo
Contacting a catalyst consisting of 1 / mg of crystalline aluminozine cosilicate and a raw material containing at least 50% by weight of an aliphatic hydrocarbon and / or alicyclic hydrocarbon having 2 to 7 carbon atoms with the aluminosine cosilicate catalyst. Is a method for producing an aromatic hydrocarbon.

Crystalline aluminosilicates containing cations are known as zeolites both naturally and synthetically. Aluminosilicate has a three-dimensional skeleton structure in which SiO ₄ tetrahedron and AlO ₄ tetrahedron are crosslinked by sharing oxygen atoms. On the other hand, the crystalline aluminozin cosilicate used in the present invention is one in which the aluminum of the aluminosilicate is partially replaced with zinc, and silicon, aluminum and zinc atoms are crosslinked by sharing oxygen, and have the same skeleton as the crystalline aluminosilicate. Have a structure. In this case, all of the silicon, aluminum, or zinc atoms do not necessarily have to have the same crystal structure, and some of them may coexist in other forms such as their respective oxides.

In the aluminozine cosilicate of the present invention, most of the cations are replaced with sodium ions, elemental analysis is performed, and the Na / Al ratio is determined.
It can be distinguished from an aluminosilicate substituted with zinc ions by ion exchange or an aluminosilicate carrying zinc. That is, the aluminosilicate substituted with zinc ions or the aluminosilicate supporting zinc has a Na / Al ratio of less than 1, while the aluminozincosilicate has a Na / Al ratio of more than 1. This is because zinc, which constitutes the crystal lattice of aluminosine cosilicate, provides a cation exchange site together with aluminum.

Further, the aluminozincosilicate and the zincosilicate of the present invention can be distinguished by the temperature programmed desorption measurement of ammonia. That is, in Zincosilicate,
A thermal desorption curve as shown in B of 300 to 45 is obtained.
While the desorption of ammonia at 0 ° C. is small, this is remarkably observed in the temperature programmed desorption curve A of aluminozine cosilicate. This is because zinc forming the crystal lattice does not generate a strong acid point, whereas aluminum forms a strong acid point.

In the crystalline aluminozin cosilicate of the present invention, the Si / Al atomic ratio is 14 to 67, the Si / Zn atomic ratio is 30 to 350, and the alkali metal content is 0.4% by weight.
It is the following. If the atomic ratio of Si / Al is less than 14, it is difficult to obtain a catalyst whose catalyst performance deteriorates slowly with time. On the other hand, if the atomic ratio of Si / Al is greater than 67, the activity of the catalyst is insufficient and deterioration with time becomes fast. Further, when the Si / Zn atomic ratio is less than 30, the formation of crystals is poor and the deterioration of the catalyst over time is rapid. On the other hand, if the atomic ratio is larger than 350, the selectivity of aromatics will be low. If the content of alkali metal, especially sodium, in the catalyst exceeds 0.4% by weight, the life of the catalyst will be shortened.

Further, in the present invention, the amount of solid strong acid contained in the catalyst is in the range of 20% to 35% of the total amount of solid acid, and the amount of brene obtained by pyridine adsorption measurement by Fourier transform infrared spectroscopy. Sted acid amount is 0.09 ~
It is characterized by being 0.16 μmol / mg. Here, the solid strong acid means one having an acidity function H ₀ of −8.2 or less, and the solid strong acid amount and the total solid acid amount can be measured by the temperature programmed desorption method of ammonia. The temperature programmed desorption method of ammonia is a method in which ammonia is adsorbed on a catalyst at a predetermined temperature, and after the adsorption is equilibrated, the desorption of ammonia is observed while raising the temperature of the catalyst layer.
The amount of ammonia desorbed up to 0 to 650 ° C is the total solid acid amount, and the amount of ammonia desorbed up to 300 to 650 ° C is the solid strong acid amount. Specifically, the catalyst temperature is 100 ° C, 10
After equilibrium adsorption of ammonia at 0 Torr and deaeration of unadsorbed ammonia, the temperature is raised to 100 ° C per minute under conditions of 7 ° C / min.
To 650 ° C., the amount of desorbed ammonia was measured, and the temperature-programmed desorption curve of FIG.
The ratio of the peak area of 300 to 650 ° C. (hatched area) to the peak area of is calculated and used as the ratio of the amount of solid strong acid to the amount of solid acid. If the ratio of the amount of solid strong acid to the amount of solid acid is more than 35%, the catalyst life is short, and if it is less than 20%, sufficient catalytic activity cannot be obtained.

The Bronsted acid is a substance capable of giving a proton to another substance, that is, a proton donor, and can be quantified by pyridine adsorption measurement by Fourier transform infrared spectroscopy (FT-IR). The measuring method is to adsorb pyridine on the acid point of the catalyst, and confirm the type of acid point of the catalyst (clear absorption of Bronsted acid and Lewis acid is recognized) from the position of its infrared absorption spectrum.
The acid amount (μmol / mg) is determined from the peak area intensity of the spectral absorption of Bronsted acid.

More specifically, the measurement method by this Fourier transform infrared spectroscopy will be described.
After performing pretreatment by evacuation, the infrared absorption spectrum of the pyridine-unadsorbed catalyst is measured to obtain the background. Next, pyridine is adsorbed on the catalyst at 150 ° C. for 20 minutes. Then, after evacuation at 150 ° C. for 1 hour, the infrared absorption spectrum is measured. An example of this infrared absorption spectrum is shown in FIG. In FIG. 2, a peak a near 1545 cm ⁻¹ is a proton-union type pyridine, which shows an absorption spectrum of pyridine adsorbed on Bronsted acid.
The peak b near 454 cm ⁻¹ shows the absorption spectrum of pyridine adsorbed by Lewis acid as a coordination pyridine. Of these, the area intensity of the peak of the absorption spectrum of pyridine adsorbed on the Bronsted acid is calculated, and then the amount of Bronsted acid (μmol / mg) is calculated from the formula (1) according to the Lambert-berr's law. . However, the integrated absorption coefficient in this measurement is 1.0 cm
μmol ⁻¹ is used.

[0016]

[Equation 1] Wherein, Ai is 1545 cm ^-1 vicinity of the peak area intensity (cm ^-1), S is the sample cross-sectional area (cm ^2), epsilon is the integral absorption coefficient (1.0cm · μmol ^-1), W is sample weight ( mg) is shown. ]

The Bronsted acid amount is 0.16 μmo.
If it is larger than 1 / mg, the catalyst life will be short and 0.09 μmo
If it is less than 1 / mg, sufficient catalytic activity cannot be obtained.

The ratio of the amount of strong solid acid to the amount of solid acid and the amount of Bronsted acid can be adjusted by various methods described later.

The crystalline aluminozin cosilicate used in the present invention preferably has an X-ray diffraction pattern shown in Table 1 similar to ZSM5 type.

[0020]

[Table 1] Powder X-ray diffraction of aluminozine cosilicate

The crystalline aluminozine cosilicate is prepared by mixing a silicon compound, an aluminum compound, a zinc compound, an alkali metal salt, water, and optionally an organic nitrogen compound and an acid, and maintaining the temperature at 100 to 220 ° C. for 3 to 200 hours. Can be synthesized.

As an example of the silicon compound, sodium silicate, potassium silicate, silica, or a mixture of two or more of them can be used.

As the aluminum compound, aluminum sulfate, aluminum nitrate, aluminum chloride, sodium aluminate, potassium aluminate, aluminum hydroxide, alumina, or a mixture of two or more thereof can be used.

As the zinc compound, zinc sulfate, zinc nitrate, zinc chloride, zinc oxide, zinc hydroxide, or a mixture of two or more thereof can be used.

As the alkali metal salt, sodium, potassium hydroxide, chloride, bromide, sulfate, nitrate, acetate, or a mixture of two or more thereof can be used.

As the organic nitrogen compound, hydroxides, bromides and chlorides of quaternary ammonium such as tetrapropylammonium, tetrabutylammonium and tripropylmethylammonium, amines such as tripropylamine, tributylamine and morpholine, triamine Amino alcohols such as ethanolamine and diethanolamine, amides such as acetamide and propionamide, alkylureas such as methylurea and 1,3-dimethylurea,
Nitriles such as acetonitrile and propionitrile, or a mixture of two or more thereof can be used.

As the acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, phosphoric acid, or a mixture of two or more of these can be used.

Further, these raw materials do not have to be used alone, and may be in a premixed state such as silica alumina, or a compound. The raw materials are not limited to those exemplified here.

The synthesized aluminosine cosilicate is ion-exchangeable, and most of the cations can be used by exchanging it with H ⁺ ions.

The amount of strong solid acid possessed by the crystalline aluminozine cosilicate is set to 20% to 35% of the total amount of solid acid, and the Bronsted acid obtained by pyridine adsorption measurement by Fourier transform infrared spectroscopy is 0.09 to 0. 16 μmol
In order to adjust the amount to / mg, the aluminozine cosilicate having an alkali metal content of 0.4% by weight or less is 400 to 700.
Steam treatment may be carried out at a temperature of 500 ° C, preferably 500 to 550 ° C. This steam treatment may be performed in a closed system by utilizing the water content adsorbed by the zeolite and / or the binder. Alternatively, it may be carried out while blowing steam in an open system such as a kiln.

The crystalline aluminozin cosilicate can be used as a catalyst as it is, or can be molded by adding a granulating agent. As the granulating agent, commonly known ones such as silica, alumina, clay, inorganic salts, organic polymers and surfactants can be used. The steam treatment is
It may be carried out either before or after molding by adding the granulating agent, but it is preferably carried out after molding.

Such crystalline aluminozine cosilicate is used as a catalyst for producing aromatic hydrocarbons from aliphatic hydrocarbons and / or alicyclic hydrocarbons having 2 to 7 carbon atoms. As an aliphatic hydrocarbon,
Ethane, propane, n-butane, iso-butane, n-
Saturated hydrocarbons such as pentane, iso-pentane, neopentane, n-hexane, methylpentane, dimethylbutane, n-heptane, methylhexane, dimethylpentane, ethylene, propylene, butene, butadiene, pentene, pentadiene, hexene, hexadiene, heptene Unsaturated hydrocarbons such as heptadiene, cyclopentene, methylcyclopentene, cyclohexene, methylcyclohexene, cycloheptene, cyclohexadiene and methylcyclohexadiene.

Further, examples of the alicyclic hydrocarbon include cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, cycloheptane, ethylcyclopentane and the like.

The raw material supplied to the reaction has 2 to 2 carbon atoms as described above.
It contains at least 50% by weight of aliphatic hydrocarbons and / or alicyclic hydrocarbons of No. 7, and is mixed with components other than the above, for example, benzene, toluene, hydrocarbons having a carbon number of C ₈ or more, methanol, dimethyl ether and the like. You can do it.

The aromatization reaction is suitably carried out in the temperature range of 350 to 600 ° C. If the reaction temperature is lower than 350 ° C., the yield of aromatic hydrocarbon is insufficient,
If it is higher than ℃, the deterioration of catalyst performance due to coke formation is rapid.
Although the feed rate of the raw material depends on the composition of the raw material, the reaction temperature, and the kind of the catalyst, the weight hourly space velocity is preferably in the range of 0.1 to 10 Hr ⁻¹ . When the weight hourly space velocity is less than 0.1 Hr ^-1 , the production efficiency of aromatic hydrocarbons is low, while 10
If it is larger than Hr ^-1, the yield of aromatic hydrocarbon is not sufficient.

The pressure of the aromatization reaction is 0 to 10 kg / cm.
Pressure ² · G are suitable. At a pressure of 10 kg / cm ² · G or higher, the yield of aromatic hydrocarbons is not high. The aliphatic hydrocarbon having 2 to 7 carbon atoms which is a reaction raw material may be supplied as it is, but may be supplied together with hydrogen, nitrogen and carbon dioxide.

[0037]

The present invention will be described below in detail with reference to examples. Preparation of catalyst (1) Solution C in which 26 g of sodium chloride and 1.9 g of tetrapropylammonium bromide were dissolved in 104 ml of distilled water, 1.34 g of zinc sulfate, 1.71 g of aluminum sulfate and 5 parts of tetrapropylammonium bromide in 60 ml of distilled water. A solution in which 0.6 g and 5.3 g of concentrated sulfuric acid were dissolved and a solution B in which 69 g of water glass No. 3 was dissolved in 45 ml of distilled water were added simultaneously and continuously while stirring. At that time, sodium hydroxide or sulfuric acid was added and adjusted so that the pH of the mixed solution was maintained at 10. This mixed solution was transferred to an autoclave, heated to 160 ° C. in 3 hours, and continuously maintained at 160 ° C. for 20 hours while stirring. After cooling, the solid matter was taken out, washed with water, immersed in an ammonium nitrate aqueous solution to replace cations with NH ₄ ⁺ ions, washed with water and dried to obtain a crystalline aluminozine cosilicate. This crystalline aluminozine cosilicate is baked at 540 ° C. for 3.5 hours,
A crystalline aluminozine cosilicate catalyst A having a lattice spacing according to the X-ray diffraction diagram shown in Table 1 was obtained.

Next, this catalyst A was left to stand overnight at room temperature in a desiccator containing a saturated aqueous solution of calcium chloride,
Adsorb 5 to 10% by weight of water. This was filled in a reactor, sealed and heat-treated at 520 ° C. The steam generated at this time increased the pressure in the system to 5 to 7 kg / cm ² · G. This was left for 1 hour for steam treatment. This was designated as catalyst B.

The catalyst A was left in a desiccator containing a saturated aqueous solution of calcium chloride at room temperature overnight,
Moisture of 5 to 10% by weight was adsorbed, and the reactor was filled with the water and sealed, and heat-treated at 600 ° C. The steam generated at this time increased the pressure in the system to 5 to 7 kg / cm ² · G. This was left for 1 hour for steam treatment. This was designated as catalyst C.

(2) In 104 ml of distilled water, 26 g of sodium chloride and 1.9 tetrapropylammonium bromide.
g of C solution, 60 ml of distilled water, and 1.3 g of zinc sulfate.
4 g, 1.71 g of aluminum sulfate, 5.6 g of tetrapropylammonium bromide, 5.3 g of concentrated sulfuric acid, and B solution of 69 g of water glass No. 3 dissolved in 45 ml of distilled water were stirred and continuously at the same time. Added to. At that time, sodium hydroxide or sulfuric acid was added and adjusted so that the pH of the mixed solution was maintained at 10. The gel was recovered from this mixture by centrifugation, crushed for 1 hour, and combined with the supernatant obtained by centrifugation. Transfer the mixture to an autoclave,
The temperature was raised to 160 ° C. in 3 hours, and the stirring was continued to 16
Hold at 0 ° C. for 20 hours. After cooling, the solid matter is taken out, washed with water, immersed in an aqueous solution of ammonium nitrate to replace cations with NH ₄ ⁺ ions, washed with water, dried, baked at 540 ° C., and the lattice according to the X-ray diffraction diagram shown in Table 1 is used. A crystalline aluminozine cosilicate with interplanar spacing was obtained. This crystalline aluminozine cosilicate is further treated at 500 ° C. for 20
The catalyst D was obtained by heating for 0 hours.

(3) To 1040 ml of distilled water, 260 g of sodium chloride and tetrapropylammonium bromide 1
Liquid C in which 9 g was dissolved was mixed with 60 ml of distilled water to prepare zinc sulfate 1.
34 g, 1.71 g of aluminum sulfate, 56 g of tetrapropylammonium bromide, and 53 g of concentrated sulfuric acid were dissolved in solution A, and solution B in which 690 g of water glass No. 3 was dissolved in 450 ml of distilled water was added simultaneously and continuously while stirring.
At that time, sodium hydroxide or sulfuric acid was added and adjusted so that the pH of the mixed solution was maintained at 10. This mixed solution was transferred to an autoclave and heated to 160 ° C for 3 hours,
It was kept at 160 ° C. for 20 hours while stirring. After cooling, the solid matter was taken out, washed with water, immersed in an aqueous ammonium nitrate solution to replace the cations with NH ₄ ⁺ ions, washed with water and dried to obtain a crystalline aluminozine cosilicate. 90 g of this crystalline aluminozine cosilicate was mixed with 10 g of a silica binder, water was added and molded, then immersed in an aqueous ammonium nitrate solution to replace the cations with NH ₄ ⁺ ions, washed with water and dried to form H-form, The mixture was put in a kiln and baked in an open system at 500 ° C. for 2 hours while supplying a large amount of water. This was designated as catalyst E.

Measurement of catalytic acid amount For each of the catalysts A to E obtained above, the amount of acid was measured by the temperature programmed desorption method of ammonia, and 100 to 650 was measured.
The ratio of the amount of solid strong acid to the total amount of solid acid was calculated from the ratio of the peak area of 300 to 650 ° C to the peak area of ° C.

The amount of Bronsted acid was determined from the peak area intensity around 1545 cm ^-1 in the absorption spectrum obtained by pyridine adsorption measurement by Fourier transform infrared spectroscopy (FT-IR), based on the formula shown above. .

Table 2 shows the composition of each of the catalysts A to E, the ratio of the amount of strong solid acid to the total amount of solid acid obtained by the above measurement, and the amount of Bronsted acid.

[0045]

[Table 2]

Aromatization reaction Each of the catalysts A to E prepared above was charged into a reactor and kept at 520 ° C., and light naphtha as a reaction raw material having the composition shown in Table 3 was subjected to a weight hourly space velocity of 5 hr ^{−. 1} for 3 kg /
Aromatization reaction was carried out by flowing under a pressure of cm ³ .

[0047]

[Table 3]

The reactor outlet gas was collected, its composition was analyzed by gas chromatography, and the conversion of light naphtha was calculated from the analysis value according to the following formula. Light naphtha conversion rate (%) = 100−C ₁ / (C ₁ +
C ₂ ) × 100 where C ₁ = light naphtha concentration in the reactor outlet gas (wt%) C ₂ = product concentration in the reactor outlet gas (wt%) Also, in order to compare the aromatic yield, the reactor The aromatic hydrocarbon concentration (% by weight) in the outlet gas was measured.

Time course curves of the conversion of light naphtha (1 to 5) and the concentration of aromatic hydrocarbons (1 'to 5') in the reactor outlet gas in the aromatization reaction carried out using catalysts A to E. Is shown in FIG. As is clear from this figure, the aluminosine cosilicate-containing catalysts of the present invention, in which the ratio of the amount of strong solid acid to the amount of fixed acid and the amount of Bronsted acid within the specified ranges, are B, E are aromatization reactions of hydrocarbons. In, the high conversion and aromatic yield are maintained for a long time. On the other hand, the catalyst having a ratio of the solid strong acid amount and the Bronsted acid amount out of this range has a high initial activity, but the activity is lowered due to long-term operation, or the initial activity itself is low.

This aromatization reaction is the result of an accelerated test under severe conditions in order to check the catalyst life, and the conversion of light naphtha was 90% in actual operation.
There is a more noticeable difference in the time to deteriorate to below
150 hours at catalyst B, 2000 hours at catalyst B, 360 at catalyst D
The time is estimated to be 800 hours with the catalyst E, and it can be seen that the catalysts B and E of the present invention are remarkably excellent.

[0051]

The present invention has a specific range of Si / Al atomic ratio,
A catalyst containing aluminazine cosilicate having a Si / Zn atomic ratio, an alkali metal content of not more than a specified amount, and a ratio of a solid strong acid amount to a solid acid amount and a Bronsted acid amount in a specified range was used. As a result, not only can aromatic hydrocarbons be obtained from aliphatic hydrocarbons and / or alicyclic hydrocarbons with high conversion and aromatic yield, but also catalyst activity can be maintained for a long time, so the catalyst life is extremely long,
This is an industrially advantageous method.

[Brief description of drawings]

FIG. 1 is a diagram showing a temperature programmed desorption curve of ammonia for aluminozincosilicate and zincosilicate.

[Explanation of symbols]

A: ammonia desorption curve of aluminozincosilicate B: desorption curve of ammonia of zincosilicate

FIG. 2 is an infrared absorption spectrum of a pyridine adsorption catalyst by Fourier transform infrared spectroscopy.

[Explanation of symbols]

a: infrared absorption peak of pyridine adsorbed on Bronsted acid b: infrared absorption peak of pyridine adsorbed on Lewis acid

FIG. 3 is a diagram showing changes over time in the conversion rate of light naphtha by various catalysts and the concentration of aromatic hydrocarbons in the outlet gas.

[Explanation of symbols]

1: conversion of light naphtha in reaction using catalyst A 2: catalyst B 〃 3: catalyst C 〃 4: catalyst D 〃 5: catalyst E 〃 1 ': aromatics in outlet gas in reaction using catalyst A Hydrocarbon concentration 2 ': Catalyst B 〃 3': Catalyst C 〃 4 ': Catalyst D 〃 5': Catalyst E 〃

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Fukase 3-17-35, Shinzonan, Toda City, Saitama Prefecture Within Japan Energy Co., Ltd. (72) Kazuhiko Suzuki 4-1-21, Nihombashi-Muromachi, Chuo-ku, Tokyo Mizusawa Chemical Co., Ltd. (72) Inventor Hiroo Inoue 4-1-21, Nihombashi Muromachi, Chuo-ku, Tokyo Mizusawa Chemical Co., Ltd. (72) Inventor Hiroshi Ono 4-1-21, Nihombashi Muromachi, Chuo-ku, Tokyo Mizusawa Chemical Co., Ltd.

Claims (4)

[Claims] 1. A raw material containing at least 50% by weight of an aliphatic hydrocarbon and / or alicyclic hydrocarbon having 2 to 7 carbon atoms and having an Si / Al atomic ratio of 14 to 67, and Si / Zn.
The atomic ratio is 30 to 350, the alkali metal content is 0.4% by weight or less, and the ratio of the solid strong acid amount to the solid acid amount is 20.
.About.35%, and the amount of Bronsted acid obtained by pyridine adsorption measurement by Fourier transform infrared spectroscopy was 0.09.
A method for producing an aromatic hydrocarbon, which comprises contacting the crystalline aluminodine cosilicate at a concentration of 0.16 μmol / mg. 2. The method for producing an aromatic hydrocarbon according to claim 1, wherein the crystalline aluminosine cosilicate has a powder X-ray diffraction peak shown below. 3. A Si / Al atomic ratio of 14 to 67,
Si / Zn atomic ratio is 30-350, alkali metal content is 0.4 wt% or less, the ratio of solid strong acid amount to solid acid amount is 20-35%, and pyridine adsorption measurement by Fourier transform infrared spectroscopy A catalyst for producing an aromatic hydrocarbon, which is obtained from the above and comprises crystalline aluminosine cosilicate having an amount of blenthred acid of 0.09 to 0.16 μmol / mg. 4. The catalyst according to claim 3, wherein the crystalline aluminozine cosilicate has a powder X-ray diffraction peak shown below.