JPH11562A - Halogen containing catalyst - Google Patents

Abstract

(57) [Summary] [Problem] A halogen content distribution in a catalyst is uniform,
As a result, an object of the present invention is to provide a catalyst for producing an aromatic hydrocarbon, which can suppress the cracking activity. A halogen-containing catalyst containing a halogen compound and having a uniform halogen content distribution in the catalyst,
In particular, the relationship between the X-ray intensity (I) and the cross-sectional width direction distance (x: distance from one catalyst surface) obtained by performing a line analysis measurement of a halogen atom in one direction on the cross section of the catalyst using an EPMA apparatus is shown. In the figure, x for I (x) is the tangent to the tangent of the curve at the minimum and minimum values of the curve representing the X-ray intensity from the integral (F) between one catalyst surface and the other catalyst surface. The ratio α [(F−F _O ) / F] between the value obtained by subtracting the integral value (F _O ) of the line intensity I _O (x) between the above and the integral value F is 0.17 or less. The above halogen-containing catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst for producing aromatic hydrocarbons, and more particularly to a halogen-containing catalyst such as a halogen-treated platinum-supported L-type zeolite catalyst having a uniform halogen content distribution and capable of suppressing decomposition activity. And a method for producing an aromatic hydrocarbon using the catalyst.

[0002]

2. Description of the Related Art Conventionally, platinum / alumina catalysts have been used as catalysts for producing aromatic hydrocarbons by aromatizing non-aromatic hydrocarbons such as aliphatic hydrocarbons. However, such a catalyst system has a drawback that it is not possible to efficiently convert a hydrocarbon having 6 or 7 carbon atoms into an aromatic hydrocarbon. In order to solve such a problem, Japanese Patent Publication No. 58-57408 proposes a catalyst in which platinum is supported on an L-type zeolite. After that, the L-type zeolite is improved in activity, selectivity, catalyst life and the like. Alternatively, various methods have been proposed to simplify the catalyst preparation method. For example, L carrying a group VIII metal
A catalyst having improved catalytic activity and catalyst life by subjecting zeolite to oxychlorination (Japanese Patent Application Laid-Open No. 60-168).
No. 539), a catalyst for treating with a solution comprising a platinum solution and a non-platinum metal salt to uniformly disperse and support platinum (Japanese Patent Application Laid-Open No. 61-138439), and an L-type zeolite treated with a halogen-containing compound. A catalyst comprising platinum supported on platinum (JP-A-62-57653); a catalyst obtained by treating a platinum-supported L-type zeolite with a halogen-containing compound (JP-A-63-91334); There has been proposed a catalyst prepared by a simple preparation method in which a component and a halogen component are simultaneously supported (JP-A-5-49936).

[0003]

However, the above-mentioned catalysts have problems in practical use, and all of them have high decomposition activity, and as a result, aromatic selectivity cannot be said to be sufficient. . The present invention has been made under the above circumstances. That is, an object of the present invention is to provide a catalyst for producing aromatic hydrocarbons, which has a uniform halogen content distribution in the catalyst and, as a result, can suppress the decomposition activity.

[0004]

Means for Solving the Problems The present inventors have been keen to solve the above-mentioned problems of the conventional catalyst and to develop a practical catalyst capable of suppressing the decomposition activity as a catalyst for producing aromatics. As a result of repeated studies, when producing the above-mentioned catalyst, a catalyst having a uniform halogen content distribution in the catalyst, which is obtained by reducing the water evaporation rate in the drying step, can effectively achieve the object of the present invention. I found that. The present invention has been completed based on such findings. That is, the present invention is a halogen-containing catalyst containing a halogen compound and having a uniform halogen content distribution in the catalyst, in particular,
The cross section of the catalyst was analyzed by Electron Probe Micro Analysis (Electron Probe Micro).
(X: distance from one catalyst surface) obtained by performing a line analysis measurement of a halogen atom in one direction using an Analysis (hereinafter, referred to as EPMA) apparatus.
In the figure showing the relationship between X-ray intensity (I) and
The x-ray intensity I of the tangent to the curve at the minimum and the minimum value of the curve showing the X-ray intensity is obtained from the integral value (F) of x from one catalyst surface to the other catalyst surface with respect to (x).
The ratio α [(F−F _O ) of the value obtained by subtracting the integrated value (F _O ) of _O (x) between the above and the above integrated value (F)
/ F] is 0.17 or less, and a method for producing an aromatic hydrocarbon from a non-aromatic hydrocarbon using the halogen-containing catalyst.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The halogen-containing catalyst of the present invention has a uniform halogen content distribution as described above.
FIG. 1 is a diagram showing a halogen content distribution in such a halogen-containing catalyst of the present invention. When a halogen atom is subjected to line analysis measurement using EPMA, the obtained cross-sectional direction distance (x) and X-ray intensity are shown. It is a figure showing the relationship of (I). FIG. 2 is a perspective view showing an example of the L-type zeolite catalyst used for the EPMA measurement.

Hereinafter, the present invention will be described in more detail with reference to FIGS. When the catalyst of the present invention has, for example, a columnar shape as shown in FIG. 2, the EPMA line analysis measurement is performed on a cut surface parallel to the bottom surface in a linear direction as shown in the figure. FIG. 1 shows the relationship between the X-ray intensity (I) indicating the halogen atom concentration on the horizontal axis and the vertical axis as the distance in the cross-sectional width direction (x: distance from one catalyst surface). The figure is shown. According to FIG. 1, the halogen-containing catalyst of the present invention is characterized in that x is the above-mentioned x in I between one catalyst surface (x = 0) and the other catalyst surface (x = x ₀ ).
Integration in; (0 to x ₀ x) between the integral value from the (F) above for x tangent of the X-ray intensity of the curve at the minimum and the minimum value of the curve indicating the X-ray intensity (I _O) of The ratio α [(F−F _O ) / F] of the value (F−F _O ) obtained by subtracting the value (F _O ) from the integral value (F) is 0.17 or less. When the above-mentioned α value is larger than 0.17, the decomposition selectivity increases, and as a result, the aromatic selectivity decreases, which is not preferable. From such a point, in the present invention, the α value is preferably 0.15 or less. In addition, the above-mentioned line analysis measurement of the present invention can be applied to any shape, and if it has the above-mentioned α value, the specific effects of the present invention can be exhibited. Therefore, the shape of the catalyst of the present invention is not particularly limited. However, in the present invention, a column having a cylindrical shape can be preferably used from the viewpoint of ease of molding and catalyst strength.

Preparation of novel L-type zeolite of the present invention
Uses a conventional L-type zeolite 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 _TwoO_Three・ 5.0-7.0SiO_Two・ 0-9H_TwoO (expression
In the formula, M represents an alkali metal or an alkaline earth metal.
And n represents the valency of M)
Specifically, JP-A-58-133835, Nos. 9-10
And JP-A-59-80333, page 5.
Is what it is. The novel L-type zeolite of the present invention comprises:
A platinum-containing compound and a halo are added to the raw material L-type zeolite.
It is prepared by supporting a gen-containing compound. like this
In addition, by supporting a platinum component and a halogen component,
To provide unprecedented excellent catalyst activity and catalyst life
Can be.

Here, the platinum-containing compound is not particularly limited as long as it can be a platinum source, but a platinum salt is usually used. Specific examples include tetraammineplatinum chloride, chloroplatinic acid, chloroplatinate, tetraammineplatinum hydroxide, dinitrodiaminoplatinum and the like. The halogen-containing compound includes various compounds and is not particularly limited. Specifically, compounds such as 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, and hydrogen bromide and ammonium bromide. And bromine-containing compounds. As the halogen-containing compound, one or a mixture of two or more of the above compounds can be used, and a combination of a chlorine-containing compound and a fluorine-containing compound is particularly preferable.

The method for preparing the novel L-type zeolite of the present invention is not particularly limited as long as a platinum component and a halogen component are supported on the raw material L-type zeolite. Any of an impregnation method, a vacuum impregnation method, a permeation method, and an ion exchange method can be used.
In order to support the platinum-containing compound and the halogen-containing compound on the raw material L-type zeolite, the supporting treatment may be performed at the same time. Alternatively, the platinum may be previously supported and then the halogen may be supported.
The reverse is also possible. The amount supported in the supporting treatment is not particularly limited, but the amount of the platinum-containing compound to be supported is usually preferably 0.1 to 5.0% by weight, more preferably 0.3 to 1.5% by weight based on the total weight of the catalyst. The range of% is optimal. Also,
The loading amount of the halogen-containing compound is generally preferably 0.1 to 5.0% by weight as halogen based on the total weight of the catalyst. When the loading amount of the platinum-containing compound and the halogen-containing compound is out of the above range, the effect of improving the catalytic activity may not be exhibited.

In the present invention, the conditions of the supporting treatment are not particularly limited and may be appropriately selected depending on the situation.
The L-type zeolite may be contacted with the platinum-containing compound and the halogen-containing compound at room temperature to 90 ° C. for 1 minute to 10 hours. In the preparation of the halogen-containing catalyst of the present invention, the supported L-type zeolite is then subjected to a drying treatment in a drying step. At this time, any of a vacuum drying method and a normal pressure drying method is used. It is possible, and in the present invention, rotary drying or vacuum rotary drying is preferable in terms of halogen distribution. Drying may be performed at a constant temperature or while increasing the temperature as long as the moisture evaporation rate is 15% by weight / hr or less. When performing while heating,
The temperature may be raised at a step rate or at a constant rate. The water evaporation rate is 15% by weight / hr
If it is larger, the halogen may be unevenly supported on the catalyst, which may be undesirable. From such a point, the water evaporation rate is more preferably 10% by weight / hr or less. In the present invention, as a preferred embodiment of the drying step, for example, a method of drying at 40 ° C. for 2 hours, then heating to 100 ° C. over 40 minutes, and performing rotary drying or vacuum rotary drying at 100 ° C. for 30 minutes, 100 over 2 hours 30 minutes
A method of heating to 100 ° C. and spin-drying or spin-drying at 100 ° C. for 30 minutes, but is not limited thereto.

The calcination of the catalyst is preferably carried out at a temperature higher than the above drying temperature, for example, preferably at a temperature of 250 to 350 ° C. If the calcination temperature is outside the above range, the catalytic activity may not be sufficient. The atmosphere at the time of firing is not particularly limited in the present invention, but can be usually performed in air. In this case, it can be carried out with air flowing, but it can also be carried out without flowing air. The halogen-containing catalyst of the present invention comprises the above-mentioned L-type zeolite. If necessary, a natural or synthetic inorganic oxide such as alumina, silica, or aluminosilicate can be added as a binder. . The use amount of these binders is preferably 5 to 90% by weight based on the total weight of the catalyst.

The hydrocarbon as a raw material to which the halogen-containing catalyst of the present invention can be applied is selected from the group consisting of paraffin hydrocarbons, olefin hydrocarbons, acetylene hydrocarbons, cyclic paraffin hydrocarbons and cyclic olefin hydrocarbons. One or more selected hydrocarbons may be mentioned. As the paraffinic hydrocarbon, a carbon number of 6 to 1 is used.
0 is preferable, and specific examples thereof include n-hexane, methylpentane, n-heptane, methylhexane, dimethylpentane, and n-octane. Examples of the olefinic hydrocarbon include olefins having 6 to 10 carbon atoms, specifically, hexene, methylpentene, heptene, methylhexene, dimethylpentene, octene, and the like. Examples of the acetylene-based hydrocarbon include those having 6 to 10 carbon atoms, specifically, hexine, heptin, and octin. Examples of the cyclic paraffinic hydrocarbon include those having 6 to 10 carbon atoms, specifically, methylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane and the like. Further, as the cyclic olefin-based hydrocarbon, those having 6 to 10 carbon atoms, specifically, methylcyclopentene, cyclohexene, methylcyclohexene,
Dimethylcyclohexene and the like can be mentioned.

[0013]

Next, the present invention will be described more specifically 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 Co., Ltd.) and kneaded and molded. Thereafter, air calcination was performed at 500 ° C. for 2 hours to obtain a silica binder molded L-type zeolite. Next, 0.086 g of tetraammineplatinum chloride and 0.086 g of ammonium fluoride were used.
Then, 088 g, 0.019 g of ammonium chloride and 2.1 g of ion-exchanged water were mixed to prepare an impregnation liquid. The impregnating solution thus prepared was gradually dropped into 5 g of the above-mentioned silica binder-molded L-type zeolite while stirring to carry out a treatment for supporting platinum and halogen. Next, in the drying step, 4
After initial vacuum spin drying at 0 ° C. for 2 hours, 100
The temperature was raised to 100 ° C., and vacuum rotary drying was performed at 100 ° C. for 30 minutes. Then, it was calcined at 320 ° C. for 1 hour in the air to prepare a catalyst.

Comparative Example 1 (1) Preparation of Catalyst 5 g of L-type zeolite subjected to the supporting treatment in Example 1 was heated from room temperature to 100 ° C. over 60 minutes, and vacuum-rotated at 100 ° C. for 3 hours. . Except for the drying step, it is the same as Example 1. Example 2 (1) Preparation of Catalyst 5 g of L-type zeolite which had been subjected to the loading treatment in Example 1
The temperature was raised from 0 ° C to 100 ° C over 2 hours 30 minutes,
Vacuum rotary drying was performed at 30 ° C. for 30 minutes. Except for the drying step, it is the same as Example 1.

Example 3 (1) Preparation of Catalyst 5 g of L-type zeolite subjected to the loading treatment in Example 1 was heated from room temperature to 90 ° C. over 2 hours while rotating at normal pressure, and then heated at 90 ° C. for 3 hours. Retention drying was performed. Except for the drying step, it is the same as Example 1. Example 4 (1) Preparation of Catalyst 5 g of the L-type zeolite subjected to the supporting treatment in Example 1 was heated from room temperature to 90 ° C. over 3 hours while rotating at normal pressure, and kept at 90 ° C. for 3 hours. Drying was performed. Except for the drying step, it is the same as Example 1.

(2) Evaluation of physical properties of catalystEPMA measurement Each of the catalysts obtained above was converted to a resin (PMMA: polymethylmeta).
(Crylate), cut parallel to the bottom and shown in Fig. 2.
Bring out such a measuring surface. Using a normal EPMA device,
Acceleration voltage 15 kV, beam size 1 μm, sample current 0.0
The α value was determined by measuring at 5 μA. The results are shown in Table 1.Pulse response evaluation For each of the catalysts obtained above, the powder was crushed to 32 to 65 mesh.
Weigh 50 mg of the crushed catalyst and fill the reactor.
After setting in the device, from a room temperature at a hydrogen flow rate of 100 cc / min.
The temperature was raised to 540 ° C in 35 minutes, and hydrogen reduction was performed at 540 ° C for 1 hour.
Do time. After hydrogen reduction is completed, the temperature is set at 460 ° C. Anti
The reactant is nC₆It was used. Pulse size 0.5μ
l, 1.0μl, 2.0μl, 3.0μl
Change the rate. The results are shown in Table 1. C_1-4Selectivity
The lower the better, the better the catalyst. Note that C _1-4Selectivity depends on product
Was calculated as follows. C_1-4Selectivity = (C_1-4Weight / (C_1-5+ Benzene) heavy
Amount) x 100

[0017]

[Table 1]

[0018]

As described above, the halogen-containing catalyst of the present invention can make the halogen content distribution in the catalyst uniform by reducing the water evaporation rate in the drying step.
As a result, the platinum can be highly dispersed, the decomposition selectivity decreases, and the aromatic selectivity increases, so that the decomposition activity can be suppressed. Therefore, the present invention is widely and effectively used in fields such as the petrochemical industry for producing aromatic hydrocarbons or the petroleum industry for producing high octane fuel.

[Brief description of the drawings]

FIG. 1 is a cross-sectional width direction distance (x) obtained when a halogen atom is subjected to a line analysis measurement using an EPMA apparatus.
FIG. 3 is a diagram illustrating a relationship between the intensity and the X-ray intensity (I).

FIG. 2 is a perspective view showing an example of an L-type zeolite catalyst used for EPMA measurement.

Claims (4)

[Claims] 1. A halogen-containing catalyst containing a halogen compound and having a uniform halogen content distribution in the catalyst. 2. A cross section of the catalyst is formed by an electron probe probe.
The relationship between the X-ray intensity (I) and the cross-sectional width direction distance (x: distance from one catalyst surface) obtained by performing a line analysis measurement of a halogen atom in one direction using a micro-analysis (EPMA) apparatus is shown. In the figure, x for the above I (x) is the X-ray of the tangent to the curve at the minimum and minimum value of the curve showing the X-ray intensity from the integral value (F) between the one catalyst surface and the other catalyst surface. A value obtained by subtracting the integral value (F _O ) between the above for the intensity I _O (x);
The halogen-containing catalyst according to claim 1, wherein a ratio α [(F- _FO ) / F] to the integral value F is 0.17 or less. 3. The halogen-containing catalyst according to claim 1, which is a halogen-treated platinum-supported L-type zeolite. 4. A method for producing an aromatic hydrocarbon from a non-aromatic hydrocarbon using the halogen-containing catalyst according to claim 1.