JPH07108771B2 - L-type zeolite and catalyst for aromatic hydrocarbon production - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an L-type zeolite and a catalyst for producing an aromatic hydrocarbon, and more specifically, a novel L-type zeolite carrying platinum and a halogen component, and an aromatic compound comprising the L-type zeolite. The present invention relates to a catalyst suitable for a chemical reaction, and a method for efficiently producing an aromatic hydrocarbon from a non-aromatic hydrocarbon such as paraffinic hydrocarbon using the catalyst.

[0002]

2. Description of the Related Art Conventionally, platinum-alumina-based catalysts have been used as catalysts for aromatizing non-aromatic hydrocarbons such as aliphatic hydrocarbons to produce aromatic hydrocarbons. However, in recent years, a method of using a platinum-supported L-type zeolite catalyst having an improved conversion rate has been proposed (Japanese Patent Publication No. 58-57408, Sho 58-2).
23614, Japanese Patent Laid-Open No. 59-80333).

However, none of the platinum-supported L-type zeolite catalysts used in these methods has a low aromatic selectivity and a short catalyst life, which is unsatisfactory. As an improved version of this, alkaline earth metals (B
Although a platinum-supported L-type zeolite catalyst into which (a, Sr, Ca) has been introduced has been proposed (Japanese Patent Laid-Open No. 58-133835), according to the follow-up examination by the present inventors, this catalyst also has an aromatic selectivity. Moreover, the catalyst life is not sufficiently improved, and the catalyst stability is low, which is not practical.

Further, by subjecting the L-type zeolite carrying a Group VIII metal to oxychlorination treatment, a catalyst having improved catalytic activity and catalyst life (Japanese Patent Laid-Open No. 60-168539).
(JP-A-61-138539), a catalyst which is treated with a solution consisting of a platinum solution and a non-platinum metal salt in order to uniformly disperse and support platinum (JP-A-61-138539), and an L-type zeolite treated with a halogen-containing compound. A catalyst supporting platinum (Japanese Unexamined Patent Publication No. 62-57653), a catalyst obtained by treating an L-type zeolite supporting platinum with a halogen-containing compound (Japanese Unexamined Patent Publication No. 63-91334), and the like have been proposed.

However, since the oxychlorination treatment is carried out at a high temperature in the step of preparing the catalyst, the processing equipment is expensive and the economy is extremely low, and the catalyst has insufficient catalytic activity. Further, in the cases of and, although the catalyst activity is improved, the catalyst life is not sufficient, and special equipment for halogen treatment is required. In addition, as the halogen-containing compound, chlorofluorocarbon, which has recently become a problem in terms of environmental impact, has been used, and its use is not environmentally desirable. As described above, the conventional catalysts have problems in preparation process, catalyst activity, catalyst life, and the like, and the present situation is that a catalyst that is practically satisfactory has not yet been proposed.

[0006]

Therefore, the present inventors have
As a catalyst for aromatic production, the above-mentioned problems of conventional catalysts are solved, and a catalyst having a high activity and a long life, which can be obtained in a simple process without requiring a special apparatus for preparation, is earnestly developed. Repeated research. As a result, a catalyst composed of an L-type zeolite that supports a platinum component and a halogen component, increases the electron density of the supported platinum, and suppresses the dealumination amount as much as possible is suitable for the above purpose. Found. The present invention has been completed based on such findings.

That is, the present invention relates to an L-type zeolite containing a halogen-containing compound and carrying a platinum-containing compound, wherein the supported X-ray absorption near edge structure of platinum. XANE
S) Provided is an L-type zeolite characterized in that the peak intensity in the measurement is 0.4 or less and the dealumination amount in the zeolite is 3% or less of the total aluminum amount. The present invention provides a catalyst for aromatic production. Furthermore, the present invention provides one or more hydrocarbons selected from the group consisting of paraffinic hydrocarbons, olefinic hydrocarbons, acetylene hydrocarbons, cyclic paraffinic hydrocarbons and cyclic olefinic hydrocarbons as described above. The present invention also provides a method for producing an aromatic hydrocarbon, which is characterized by contacting with a catalyst.

Preparation of the novel L-type zeolite of the present invention
Conventional L-type zeolite is used as a raw material. here
The raw material L-type zeolite has a composition formula of 0.9 to 1.3M._{2 / n}O
Al ₂O₃・ 5.0-7.0SiO₂・ 0-9H₂O (expression
Inside, M is an alkali metal or alkaline earth metal
However, n shows the valence of M. )
Specifically, specifically, JP-A No. 58-133835, No. 9 to
Disclosed on page 10 and page 5 of JP-A-59-80333.
It has been done.

The novel L-type zeolite of the present invention is prepared by supporting the above-mentioned starting L-type zeolite with a platinum-containing compound and a halogen-containing compound. Thus, by supporting the platinum component and the halogen component, it is possible to impart unprecedentedly excellent catalytic activity and catalyst life.

Here, the platinum-containing compound is not particularly limited as long as it serves as a platinum source, but a platinum salt is usually used. Specific examples thereof include tetraammineplatinum chloride, chloroplatinic acid, chloroplatinate, tetraammineplatinum hydroxide, and dinitrodiaminoplatinum.

As the halogen-containing compound, various compounds can be mentioned. Specifically, chlorine-containing compounds such as hydrogen chloride and ammonium chloride, fluorine-containing compounds such as hydrogen fluoride and ammonium fluoride, iodine-containing compounds such as hydrogen iodide and ammonium iodide, hydrogen bromide and ammonium bromide, etc. Examples thereof include bromine-containing compounds. As the halogen-containing compound, one kind or a mixture of two or more kinds of the above compounds may be used.

The method for preparing the novel L-type zeolite of the present invention is not particularly limited as long as it is a method in which the platinum component and the halogen component are supported on the starting material L-type zeolite, and the usual atmospheric pressure is used. It can be performed by an impregnation method, a vacuum impregnation method, an infiltration method, an ion exchange method, or the like. When the platinum-containing compound and the halogen-containing compound are loaded on the starting material L-type zeolite, they can be loaded simultaneously, or they can be loaded with platinum and then loaded with halogen, or vice versa. The supported amount in the supporting treatment is not particularly limited, but the supported amount of the platinum-containing compound is usually 0.1 to 5 as platinum based on the total weight of the catalyst.
0 wt% is preferable, and the range of 0.3 to 1.5 wt% is most suitable. Further, the supported amount of the halogen-containing compound is preferably 0.1 to 5% by weight in terms of halogen based on the total weight of the catalyst. Further, the dealumination amount in the L-type zeolite of the present invention is preferably as small as possible, usually 0 to 3.0% by weight, preferably 0 to 2.0% by weight based on the amount of aluminum in the skeleton of the starting L-type zeolite. , And more preferably 0 to 1.0% by weight. Here, the amount of dealumination in the L-type zeolite is measured by determining the proportion of the coordination of aluminum atoms around the Si atom by ²⁹ Si-NMR measurement, and thereby calculating the amount of aluminum in the skeleton. . Furthermore, the platinum X supported on the L-type zeolite of the present invention
The peak intensity measured by ANES is 0.4 or less. Here, XANES, that is, the X-ray near absorption edge structure reflects the electronic state of the measurement element. The above XANES measurement is
The L3 absorption edge of platinum in L-type zeolite was measured, and the obtained X-ray absorption spectrum includes background absorption due to coexisting atoms. The XANES spectrum as shown in FIG. 2 is obtained by approximating the Victoreen equation as the background absorption. This XANES
The spectrum is related to the number of v-band holes and is considered to represent the electron density of platinum. The obtained XANES
The following parameters were measured from the spectrum. h: (Initial peak top intensity)-(Initial valley intensity) H: Intensity at 12.7 keV The parameter (h / H) thus obtained is X
It means the peak intensity measured by ANES. L of the present invention
Type zeolite, h / H is 0.4 or less, preferably
It is 0.3 or less, and more preferably 0.25 or less. In the present invention, the conditions of the supporting treatment are not particularly limited and may be appropriately selected depending on various situations, but are from room temperature to 90 ° C. for 1 minute to
The L-type zeolite may be contacted with the platinum-containing compound and the halogen-containing compound for 10 hours.

The catalyst of the present invention comprises the above-mentioned L-type zeolite, but if necessary, a natural or synthetic inorganic oxide such as alumina, silica, aluminosilicate, etc. can be added as a binder. . The amount of these binders used is preferably 5 to 90% by weight based on the total weight of the catalyst.

As described above, the catalyst of the present invention has a special device,
It can be prepared without any steps. The obtained catalyst is used as a so-called aromatization catalyst for producing aromatic hydrocarbons in high yield from various hydrocarbons under appropriate reaction conditions, but according to the method of the present invention, it is extremely efficient. Aromatic hydrocarbons can be produced well.

In the method for producing an aromatic hydrocarbon of the present invention, the group consisting of paraffinic hydrocarbons, olefinic hydrocarbons, acetylene hydrocarbons, cyclic paraffinic hydrocarbons and cyclic olefinic hydrocarbons as the starting hydrocarbons. One or two or more kinds of hydrocarbons selected from the above are used in contact with the catalyst of the present invention to produce an aromatic hydrocarbon.

The paraffinic hydrocarbon preferably has 6 to 10 carbon atoms, specifically, n-hexane, methylpentane, n-heptane, methylhexane,
Examples thereof include dimethyl pentane and n-octane.

Examples of the olefinic hydrocarbons include olefins having 6 to 10 carbon atoms, specifically hexene, methylpentene, heptene, methylhexene, dimethylpentene, octene and the like. As the acetylene-based hydrocarbon, those having a carbon number of 6 to 10, specifically, hexyne, heptin, octyne and the like can be mentioned.

The cyclic paraffin hydrocarbon has a carbon number of 6 to 10, specifically, methylcyclopentane,
Examples thereof include cyclohexane, methylcyclohexane and dimethylcyclohexane. Further, the cyclic olefin hydrocarbon has a carbon number of 6 to 10,
Specific examples include methylcyclopentene, cyclohexene, methylcyclohexene, dimethylcyclohexene and the like.

The method of the present invention proceeds by bringing the above-mentioned raw material hydrocarbon into contact with the above-mentioned catalyst, and there are no particular restrictions on the conditions at that time. However, in order to obtain good results, a temperature of 350-600 ° C, preferably 400
˜550 ° C., pressure 0-40 kg / cm ² G, preferably 0-10 kg / cm ² G, liquid hourly space velocity (LHSV) 0.
It should be ¹ to 20 hr ^-1 , preferably ¹ to 10 hr ^-1 . In addition, the hydrogen gas / feedstock hydrocarbon feed ratio is 0.1.
If it is selected in the range of ˜50 mol / mol, even better results can be expected.

[0020]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. Example 1 (1) Preparation of catalyst L-type zeolite (manufactured by Tosoh Corporation; TSZ-500KO)
A) 100 parts by weight of silica binder (Nissan Chemical Co., Ltd.)
(Manufactured by Snowtex) 20 parts by weight was added and kneaded and molded. Then, air baking was performed at 500 ° C. for 2 hours to obtain a silica binder-molded L-type zeolite. Then 1.39 g of 3.6% by weight hydrogen chloride solution, ammonium fluoride 0.0
97 g, tetraammineplatinum chloride 0.171 g and ion-exchanged water 3.6 g were mixed to prepare an impregnating solution. The impregnating solution prepared in this manner was used as the above silica binder molding L.
The mixture was gradually added dropwise to 10 g of type zeolite while stirring, and platinum and halogen loading treatments were simultaneously performed. Then, after drying at room temperature overnight, the catalyst was prepared by treating in air at 300 ° C. for 30 minutes.

(2) Production of Aromatic Hydrocarbon 0.5 g of the catalyst prepared in Example (1) was charged into a quartz reaction tube and treated in a hydrogen stream at 540 ° C. for 24 hours. Then, light naphtha and hydrogen having a weight composition ratio of n-hexane / isohexane / methylcyclopentane = 49/43/8 are supplied at a weight hourly space velocity of 2 hr ⁻¹ and hydrogen / light naphtha = 5 mol / mol, respectively. Pressure 5kg /
It was adjusted to cm ² G and temperature of 500 ° C., and the conversion reaction to aromatic was carried out. The change with time in the aromatic yield at this time is shown in FIG.

Comparative Example 1 (1) Preparation of Catalyst L Silica binder molding L obtained in Example 1 (1) above
20 g of type zeolite was filled in a quartz reaction tube and maintained at 200 ° C. for 30 minutes while flowing nitrogen, and then the gas was switched to monochlorotrifluoromethane and the temperature was raised to 500 ° C. After heating to 500 ° C. and treating for 2 hours, the gas was switched to nitrogen again and the temperature was lowered to obtain a halogen-treated L-type zeolite. Next, this halogen-treated L-type zeolite
An impregnating solution consisting of 0.171 g of tetraammineplatinum chloride and 4.0 g of ion-exchanged water was gradually added dropwise to 0 g of the solution while stirring to carry it. After loading, the catalyst was prepared by drying in a dryer at 80 ° C. for 3 hours.

(2) Production of Aromatic Hydrocarbon In Comparative Example 1 as the catalyst in the above Example 1 (2)
Example 1 except that the catalyst obtained in (1) was used
The conversion reaction was carried out in the same manner as in (2). The time-dependent change in aromatic yield is shown in FIG.

Comparative Example 2 (1) Preparation of catalyst Silica binder molded L obtained in Example 1 (1) above
Tetraammineplatinum chloride 0.
An impregnating solution consisting of 171 g and ion-exchanged water 4.8 g was gradually added dropwise with stirring, dried at room temperature for 2 hours, and further treated in air at 80 ° C. for 3 hours to obtain a catalyst. The obtained catalyst was filled in a quartz reaction tube, kept at 200 ° C. for 1 hour while flowing nitrogen, and then heated to 480 ° C. At 480 ° C., the gas was changed to Freon 112 / nitrogen = 0.1 / 99.9 (volume%) and treated for 10 hours. Then, the gas was switched to nitrogen again and the temperature was lowered to prepare a catalyst.

(2) Production of Aromatic Hydrocarbon In Comparative Example 2 as the catalyst in Example 1 (2) above.
Example 1 except that the catalyst obtained in (1) was used
The conversion reaction was carried out in the same manner as in (2). The time-dependent change in aromatic yield is shown in FIG.

Example 2 (1) Preparation of catalyst The same as in Example 1 (1) above.

(2) Production of aromatic hydrocarbons 0.05 g of the catalyst obtained in Example 2 (1) was sampled and charged in a pulse reactor. Then, the temperature was raised to 500 ° C. over 1 hour in a hydrogen stream, and the temperature was kept at 500 ° C. for 1 hour. The reaction temperature was adjusted to 470 ° C., and 3 microliters of n-hexane was pulsed in a hydrogen stream (2.2 liter / hour),
The conversion reaction was carried out. The yield of benzene in this case is 55.7%
Met.

Comparative Example 3 (1) Preparation of catalyst Silica binder molding L obtained in Example 1 (1) above
Tetraammineplatinum chloride 0.171 on 10g type zeolite
g and ion-exchanged water 4.8 g were added dropwise with stirring, and the mixture was dried overnight at room temperature and then in air 30
The catalyst was prepared by treating at 0 ° C. for 30 minutes.

(2) Production of aromatic hydrocarbon In the above Example 2 (2), the above Comparative Example 3 was used as a catalyst.
Example 2 except that the catalyst obtained in (1) was used.
The conversion reaction was carried out in the same manner as in (2). The yield of benzene at this time was 32.1%.

Example 3 (1) Preparation of catalyst L-type zeolite (manufactured by Tosoh Corporation; TSZ-500KO)
A) 100 parts by weight of silica binder (Nissan Chemical Co., Ltd.)
(Manufactured by Snowtex) 20 parts by weight was added and kneaded and molded. Then, air baking was performed at 500 ° C. for 2 hours to obtain a silica binder-molded L-type zeolite. Next, 0.097 g of ammonium fluoride and tetraammineplatinum chloride.
171 g and ion-exchanged water 4.8 g were mixed to prepare an impregnation liquid. The impregnating solution thus prepared was gradually added dropwise to 10 g of the above-mentioned silica binder-molded L-type zeolite while stirring to simultaneously carry out platinum and halogen loading treatment. Then, after drying overnight at room temperature, 300 in air
The catalyst was prepared by treating at 3 ° C. for 3 hours.

(2) Production of Aromatic Hydrocarbon 0.5 g of the catalyst prepared in Example 3 (1) was charged into a quartz reaction tube and treated in a hydrogen stream at 540 ° C. for 24 hours. Next, light naphtha having a weight composition ratio of n-hexane / isohexane / methylcyclopentane = 49/43/8 was supplied at a weight hourly space velocity of 16 hr ⁻¹ and hydrogen / light naphtha = 5 mol / mol, and a pressure of 5 kg. / Cm ²
After adjusting G and temperature to 517 ° C., the temperature was maintained for 20 hours to carry out a conversion reaction to an aromatic compound. The yield of aromatics in this case is 52.
It was 9%.

Example 4 (1) Preparation of catalyst Silica binder molding L obtained in the above Example 3 (1)
Type zeolite 10g to ammonium fluoride 0.097g,
Ammonium chloride 0.075 g, tetraammine platinum chloride
An impregnation liquid consisting of 0.171 g and 4.8 g of ion-exchanged water was gradually added dropwise with stirring, dried overnight at room temperature, and further treated in air at 300 ° C. for 3 hours to prepare a catalyst.

(2) Production of Aromatic Hydrocarbon In Example 3 (2), the above-mentioned Example 4 was used as a catalyst.
Example 3 except that the catalyst obtained in (1) was used.
The conversion reaction was carried out in the same manner as in (2). At this time, the yield of aromatics was 63.8%.

Example 5 (1) Preparation of catalyst Silica binder molding L obtained in the above Example 3 (1)
Type zeolite 10g to ammonium fluoride 0.097g,
Ammonium bromide 0.061 g, tetraammine platinum chloride
An impregnation liquid consisting of 0.171 g and 4.8 g of ion-exchanged water was gradually added dropwise with stirring, dried overnight at room temperature, and further treated in air at 300 ° C. for 3 hours to prepare a catalyst.

(2) Production of aromatic hydrocarbon In Example 3 (2), the above-mentioned Example 5 was used as a catalyst.
Example 3 except that the catalyst obtained in (1) was used.
The conversion reaction was carried out in the same manner as in (2). At this time, the yield of aromatics was 60.9%.

Comparative Example 4 (1) Preparation of Catalyst Silica Binder Molded L Obtained in Example 3 (1) Above
Tetraammineplatinum chloride 0.171 on 10g type zeolite
g and ion-exchanged water (4.8 g) are slowly added dropwise with stirring, dried at room temperature for 2 hours, and further in air 1
It was treated at 20 ° C. for 3 hours to obtain a platinum-supported catalyst.

(2) Production of aromatic hydrocarbon In Example 3 (2), the catalyst of Comparative Example 4 was used as the catalyst.
Example 3 except that the catalyst obtained in (1) was used.
The conversion reaction was carried out in the same manner as in (2). At this time, the yield of aromatics was 35.2%.

Example 6 (1) Preparation of catalyst L-type zeolite (manufactured by Tosoh Corp .: TSZ-500KO)
A) 100 parts by weight of silica binder (Nissan Chemical Co., Ltd.)
(Manufactured by: Snowtex) 20 parts by weight was added and kneaded and molded. Then, air baking was performed at 500 ° C. for 2 hours to obtain a silica binder-molded L-type zeolite. Next, tetraammineplatinum chloride 0.171 g, ammonium fluoride 0.1
67 g, ammonium chloride 0.075 g and deionized water
An impregnation liquid was prepared by mixing 4.5 g. The impregnating liquid thus prepared was gradually added dropwise to 10 g of the above silica binder-molded L-type zeolite with stirring to carry out a platinum and halogen supporting treatment. Then, after drying, 3 in air
The catalyst was prepared by treating at 00 ° C. for 3 hours.

(2) Evaluation of physical properties of catalyst Amount of dealumination The catalyst of Example 6 (1) was subjected to ²⁹ Si-NMR measurement, the measurement result was separated into waveforms, and the amount of aluminum in the skeleton was calculated. The dealumination amount was determined in comparison with zeolite. This value is shown in Table 1. XANES measurement The catalyst of Example 6 (1) above was subjected to hydrogen reduction (hydrogen flow rate 6.5 liter / hr) at 540 ° C. for 24 hours, the sample was crushed and molded, and put into an in situ measurement device, and again at 540 ° C., 1 Hydrogen reduction (hydrogen flow rate 10 cc / min) was performed for an hour. Then, the system was evacuated at the same temperature, cooled to room temperature, and then nitrogen was introduced to seal the system. XANES measurement was performed using the sample thus prepared. The results obtained were calculated according to the definitions given above. This value is shown in Table 1.

(3) Aromatic hydrocarbon production reaction After charging 0.25 g of the catalyst of Example 6 (1) above into a quartz reaction tube, hydrogen reduction was performed at 540 ° C. for 24 hours (hydrogen flow rate 6.5).
Liter / hr). Then, light naphtha having a weight composition ratio of n-hexane / isohexane / methylcyclopentane = 49/43/8 and hydrogen are supplied at a weight hourly space velocity of 32 h ⁻¹ and hydrogen / hydrocarbon = 5 mol / mol, respectively. The pressure was adjusted to 5 kg / cm ² G and the external temperature was adjusted to 517 ° C., and the conversion reaction to aromatic hydrocarbon was performed. The aromatic yield after 5 hours from the start of the reaction is shown in Table 1.

Comparative Example 5 (1) Preparation of catalyst Silica binder molded L obtained in Example 6 (1) above
20 g of type zeolite was filled in a quartz reaction tube and kept at 200 ° C. for 30 minutes while flowing nitrogen, after which the gas was switched to monochlorotrifluoromethane and the temperature was raised to 500 ° C. After the temperature was raised to 500 ° C. and treated for 2 hours, the gas was switched to nitrogen again and the temperature was lowered to room temperature to obtain a halogen-treated L-type zeolite having the same halogen amount as in Example 6. Next, to 10 g of this halogen-treated L-type zeolite, an impregnating solution consisting of 0.171 g of tetraammineplatinum chloride and 4.5 g of ion-exchanged water was gradually added dropwise with stirring to carry the particles. After the supporting, the catalyst was prepared by drying in a dryer at 120 ° C. for 3 hours.

(2) Evaluation of physical properties of catalyst In Comparative Example 5 as a catalyst in the above Example 6 (2)
Example 6 except that the catalyst obtained in (1) was used.
It carried out like (2). The values at that time are shown in Table 1.

(3) Production Reaction of Aromatic Hydrocarbon In Comparative Example 5 as the catalyst in Example 6 (3) above.
Example 6 except that the catalyst obtained in (1) was used.
It carried out like (3). The values at that time are shown in Table 1.

Comparative Example 6 (1) Preparation of Catalyst L Silica binder molding L obtained in Example 6 (1) above
Tetraammineplatinum chloride 0.
An impregnating solution consisting of 171 g and ion-exchanged water 4.5 g was gradually added dropwise with stirring to carry the particles. After the supporting, the catalyst was prepared by drying at 120 ° C. for 3 hours with a dryer.

(2) Evaluation of physical properties of catalyst In the above-mentioned Example 6 (2), the catalyst of Comparative Example 6 was used as a catalyst.
Example 6 except that the catalyst obtained in (1) was used.
It carried out like (2). The values at that time are shown in Table 1.

(3) Aromatic Hydrocarbon Production Reaction In the above Example 6 (3), the above Comparative Example 6 was used as a catalyst.
Example 6 except that the catalyst obtained in (1) was used.
It carried out like (3). The values at that time are shown in Table 1.

Comparative Example 7 (1) Preparation of catalyst 0.107 g of potassium fluoride, 0.0735 of potassium chloride
g, tetraammineplatinum chloride 0.120 g and ion-exchanged water 3.50 g were mixed to prepare an impregnating solution. The impregnating liquid thus prepared was gradually added dropwise to 7 g of the silica binder-molded L-type zeolite obtained in Example 6 (1) while stirring. Then, it was dried at room temperature overnight and then treated in air at 300 ° C. for 30 minutes to prepare a catalyst.

(2) Evaluation of physical properties of catalyst In the above-mentioned Example 6 (2), the above-mentioned Comparative Example 7 was used as a catalyst.
Example 6 except that the catalyst obtained in (1) was used.
It carried out like (2). The values at that time are shown in Table 1.

(3) Aromatic Hydrocarbon Production Reaction In the above Example 6 (3), the above Comparative Example 7 was used as a catalyst.
Example 6 except that the catalyst obtained in (1) was used.
It carried out like (3). The values at that time are shown in Table 1.

[0050]

[Table 1]

From the above results, the treatment with the inorganic halogen compound suppressed the production of dealumination and made it possible to prepare a catalyst having a high electron density of platinum. Moreover, such a catalyst also showed high activity in the aromatization reaction of hydrocarbons.

[0052]

INDUSTRIAL APPLICABILITY As described above, the catalyst of the present invention can be prepared by a simple process which has been conventionally carried out without the need for a special device and the like, and can enhance aromatic hydrocarbons from various hydrocarbons. It can be produced with high activity and high yield and stably for a long period of time, and can be effectively used as a catalyst for producing aromatic hydrocarbons. Further, according to the method for producing an aromatic hydrocarbon of the present invention, it is possible to produce an aromatic hydrocarbon in a high yield, and since the catalyst can maintain high activity for a long time, continuous operation over a long period of time is performed. Also, the yield of aromatic hydrocarbons is very high. Furthermore, the catalyst of the present invention has a significantly improved catalyst life,
The catalyst has an industrial advantage that the frequency of regeneration is reduced, the productivity is improved, and the manufacturing cost is reduced, and its utility value is very high. Therefore, the present invention can be widely and effectively utilized in the fields such as the petrochemical industry for producing aromatic hydrocarbons and the petroleum industry for producing high octane fuel.

[Brief description of drawings]

FIG. 1 is a graph showing changes with time in aromatic yield in Example 1, Comparative Example 1 and Comparative Example 2.

FIG. 2 is an XANES spectrum of a platinum-containing compound in L-type zeolite.

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Claims (4)

[Claims] 1. An L-type zeolite containing a halogen-containing compound and supporting a platinum-containing compound, wherein the supported platinum has a peak intensity of 0.4 or less in the X-ray near-absorption edge structure measurement. Further, the amount of dealumination in the zeolite is 3% or less of the total amount of aluminum, L-type zeolite. 2. A catalyst for producing an aromatic hydrocarbon, which comprises the L-type zeolite according to claim 1. 3. One or more hydrocarbons selected from the group consisting of paraffinic hydrocarbons, olefinic hydrocarbons, acetylene hydrocarbons, cyclic paraffinic hydrocarbons and cyclic olefinic hydrocarbons. A method for producing an aromatic hydrocarbon, which comprises bringing the catalyst into contact with the catalyst of 2. 4. Hydrocarbons at a temperature of 350 to 600 ° C., a pressure of 0 to 40 kg / cm ² G, and a liquid hourly space velocity of 0.1 to 20 h.
The method for producing an aromatic hydrocarbon according to claim 3, wherein the catalyst is brought into contact with r ^-1 and the hydrogen gas / hydrocarbon feed ratio of 0 to 50 (molar ratio).