KR20010013357A - Halogen-Containing Catalyst and Process for Preparing Same - Google Patents

Abstract

A halogen-containing catalyst wherein halogen is uniformly distributed, particularly one exhibiting an alpha ratio of 0.17 or below in the figure obtained in the line analysis of the section of the catalyst for halogen atoms in one direction with an electron probe microanalyzer (EPMA) which shows a curve of intensity (I) of X-rays vs. distance (x) in the sectional widthwise direction (from one surface of the catalyst), with the alpha ratio being defined by the formula: (F-F 0)/F (wherein F is an intensity value of X-rays obtained by integrating the above curve I(x) between one of the surfaces of the catalyst and the other thereof anf F 0 is one obtained by integrating the tangent line I 0 (x) of the above curve at the minimum and lowest point thereof between them; and a process for the preparation of a halogen-containing catalyst, characterized by making a carrier such as L-zeolite support a halogen thereon and drying the resulting carrier at an evaporation rate of moisture of 15 wt.%/h or below. The catalyst has a uninform halogen distribution and is therefore lowered in the decomposing activity, thus being suitable for the preparation of aromatic hydrocarbons.

Description

Halogen-containing catalyst and method for preparing same {Halogen-Containing Catalyst and Process for Preparing Same}

To date, platinum-alumina catalysts have been used to produce aromatic hydrocarbons by aromatizing non-aromatic hydrocarbons such as aliphatic hydrocarbons. However, platinum-alumina catalysts have the drawback that they cannot effectively convert hydrocarbons having 6 or 7 carbon atoms into aromatic hydrocarbons.

In order to overcome such a problem, a catalyst in which platinum is immobilized on an L-type zeolite is disclosed in Japanese Patent Publication No. 57408/1983, in order to improve the activity of the catalyst, selectivity of the catalyst, catalyst life, or the like, or Various methods for the L-type zeolite have been proposed to simplify the catalyst preparation method.

For example, (1) a catalyst which improves catalytic activity and catalyst life by oxychlorination of L-type zeolite which fixes Group VIII metal (Japanese Patent Application Publication No. 168539/1985), (2) uniformly dispersing platinum, Catalysts treated with a platinum solution and a solution containing a non-platinum metal salt for the purpose of immobilization (Japanese Patent Application Laid-open No. 138539/1986), (3) a catalyst in which platinum is immobilized on an L-type zeolite treated with a halogen-containing compound, ( 4) Fixing and treating at least one halogen compound and platinum component simultaneously on a catalyst obtained by treating L-type zeolite fixed with platinum with a halogen-containing compound (Japanese Patent Application Laid-open No. 91334/1998) and (5) L-type zeolite A catalyst (Japanese Patent Application Laid-Open No. 49936/1993) obtained by a simple manufacturing method including the same has been proposed.

However, the catalysts mentioned in (1) to (5) have some problems in practical use, and the cracking activity is high in all catalysts. In conclusion, aromatic selectivity is insufficient.

The present invention relates to a catalyst used in the production of aromatic hydrocarbons and a process for producing the same. More specifically, the present invention relates to a halogen-containing catalyst and one or more halogen components immobilized on the L-type zeolite and a halogen-containing catalyst such as a platinum catalyst, in which the amount of halogen is uniform, and that the cracking activity can be reduced. It relates to a manufacturing method.

Figure 1 illustrates the relationship between the widthwise distance (x) and the X-ray intensity (I) when halogen atoms are subjected to linear analytical measurements using an EPMA device.

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

Best way to carry out the invention

The halogen-containing catalyst of the present invention has a uniform distribution of halogen amounts as mentioned above. FIG. 1 illustrates the relationship between the widthwise distance (x) and the X-ray intensity (I) when linear analysis is performed on halogen atoms using the distribution of halogen amounts and EPMA in the halogen-containing catalyst of the present invention. . In addition, FIG. 2 is a perspective view showing an example of an L-type zeolite catalyst used for the aforementioned EPMA measurement.

The invention will be described in more detail with reference to FIGS. 1 and 2.

If the catalyst of the present invention is cylindrical, for example as shown in Fig. 2, the EPMA linear analysis is performed in the straight direction shown in the figure with respect to the cut plane parallel to the bottom surface. FIG. 1 shows the obtained linear analysis measurement results associated with the relationship between the cross-sectional area direction distance (x: distance from one catalyst surface) in the abscissa and the X-ray intensity (I) indicative of the halogen atom concentration in the ordinate. According to Fig. 1, in the halogen-containing catalyst of the present invention, the cross-sectional widthwise distance (x: one side) obtained by performing linear analytical measurements in one direction using an electron probe microanalysis (EPMA) device on halogen atoms on the catalyst cross section. In the figure showing the relationship between the distance from the catalyst surface of the surface and the X-ray intensity (I), the above relation with respect to x between one catalyst surface (x = 0) and the other catalyst surface (x = x ₀ ). From the integral value F of I, the integral value of the X-ray intensity I _{0 which} is the tangent of the curve with respect to the minimum and minimum values of the curve indicating the X-ray intensity with respect to x between one catalyst surface and the other catalyst surface. The ratio α [(FF ₀ ) / F] between the value obtained by subtracting (F ₀ ) and the integral value F is 0.17 or less. If the alpha value is 0.17 or more, the cracking selectivity increases, and as a result, the aromatic selectivity decreases, which is undesirable. In view of this, the alpha value of the present invention is preferably 0.15 or less.

In addition, the above-described linear analytical measurement of the present invention can be applied to a catalyst having any shape, and a unique effect on the present invention can be exerted as long as the catalyst has the above-mentioned alpha value. Therefore, there is no particular limitation on the shape of the catalyst according to the present invention. However, in the present invention, the catalyst having a cylindrical shape can be preferably used in view of convenience of casting and catalyst strength.

In order to prepare the novel L-type zeolite catalyst of the present invention, an existing L-type zeolite is used as a raw material. A raw material L-type zeolite has the composition formula _{0.9-1.3M 2 / n O · Al 2} O 3 · 5.0-7.0SiO 2 · 0-9H 2 O ( wherein M is an alkali metal or alkaline earth metal, and n is the valence of M And zeolite, examples of general zeolites are disclosed on pages 9 to 10 of Japanese Patent Application Publication No. 133835/1983 and on page 5 of Japanese Patent Application Publication No. 80333/1984.

The novel L-type zeolite catalysts of the present invention can be prepared by immobilizing one or more halogen components and metal-containing compounds, in particular platinum-containing compounds, on the abovementioned raw material L-type zeolites. By fixing one or more halogen components and metal components such as platinum components in this manner, catalysts having excellent catalytic activity and catalyst life that have not existed to date can be prepared.

Examples of halogen containing compounds include various compounds, with no particular limitation. Examples of common halogen-containing compounds include chlorine-containing compounds such as hydrochloric acid and ammonium chloride, hydrogen fluoride, fluorine-containing compounds such as ammonium fluoride, iodine-containing compounds such as hydrogen iodide and ammonium iodide, and bromine-containing compounds such as hydrogen bromide and ammonium bromide. Compound. With regard to halogen-containing compounds, the above-mentioned compounds may be used alone or in a mixture of two or more, with a mixture of chlorine-containing compounds and fluorine-containing compounds being particularly preferred.

In addition, a platinum-containing compound is preferably used as the metal-containing compound, and platinum salts are generally used, although no particular limitation is placed on the platinum-containing compound as long as the compound is a platinum raw material. General examples of platinum containing compounds include tetrachlorine chloride, chloroplatinic acid, chloroplatinum salts, tetramineplatinum hydroxide and dinitrodiaminoplatinum.

In the process for producing the novel L-type zeolite catalyst of the present invention, there is no particular limitation on the method of fixing the metal component such as platinum component and at least one halogen component on the raw material L-type zeolite, and is generally performed in the atmosphere. Filling method, vacuum filling method, osmotic pressure method and ion exchange method can be used. In addition, when the metal-containing compound and the at least one halogen-containing compound are fixed to the raw material L-type zeolite, they may be fixed at the same time, or the metal may be fixed first and then the halogen may be fixed later. The reverse procedure is also possible.

In the fixing step, no particular limitation is imposed on the amount of the immobilized compound, and the amount of the metal containing compound such as the platinum containing compound to be immobilized is generally preferably 0.1 to 5.0% by weight as the metal content relative to the total weight of the catalyst, in particular 0.3 To 1.5% by weight is most preferred. In addition, the amount of one or more halogen-containing compounds to be fixed is generally preferably 0.1 to 5.0% by weight as halogen content relative to the total weight of the catalyst. When the metal-containing compound and the halogen-containing compound to be fixed are outside the above-mentioned ranges, the effect of improving the catalytic activity sometimes does not appear.

In the present invention, no particular limitation is imposed on the fixing conditions, and may be appropriately selected in some cases. In general, L-type zeolites can cause contact with one or more halogen-containing compounds and metal-containing compounds for 1 minute to 10 hours from room temperature to 90 ° C.

In the preparation of the halogen-containing catalyst of the present invention, the fixed L-zeolite is dried after one or more halogens and metals are fixed, or between steps of fixing the metals and halogens, wherein the vacuum drying and atmospheric drying methods Can be used. In the present invention, rotation drying or vacuum rotation drying methods are preferred in view of halogen distribution.

In addition, in the present invention, after the halogen fixing is performed, it is preferable to perform drying at a relatively slow speed. If metals such as platinum and one or more halogen compounds are fixed in this order continuously, it is preferred that the drying rate is relatively slow in the drying step after halogen fixing. Instead, if more than one halogen component and the metal are fixed in this order continuously, the drying rate in the drying step after halogen fixing, i.e., the drying rate in the drying step between the halogen fixing step and the metal fixing step is relatively slow. desirable. It is also preferable to dry the zeolite slowly in the drying step after supporting the metal as well as in the drying step between the step of fixing at least one halogen component and the metal in this order continuously.

Instead, if the metal and one or more halogen components are fixed at the same time, it is preferable that the drying rate is slow in the drying step after fixing.

Depending on the drying operation, drying is preferably carried out at a low temperature primarily for a specific time and then at a high temperature, or when the drying is performed at an elevated temperature, it is preferable to reduce the rate of temperature rise.

In addition, the vacuum drying method is particularly preferable among the above-mentioned drying methods in order to remove moisture from the system. In the vacuum drying method, the degree of vacuum is optional within the range satisfying the water evaporation rate of the present invention, but is preferably 5 to 750 torr, more preferably 30 to 720 torr.

In addition, in the drying step mentioned above, drying is preferably performed at a water evaporation rate of 15% by weight or less per hour. If the moisture evaporation rate exceeds 15% by weight, the halogens are fixed unevenly on the catalyst, which is sometimes undesirable. In this respect, the water evaporation rate is more preferably 10% by weight or less per hour. If the moisture evaporation rate is 15% by weight or less per hour, drying can be carried out at a constant temperature or at an elevated temperature. When drying is carried out at an elevated temperature, the temperature rises at a step rate or at a constant rate. In the present invention, drying is carried out at a temperature of 25 to 65 ° C. for 10 to 180 minutes, and then the temperature is raised to 70 to 250 ° C. for 5 to 120 minutes, the temperature is maintained for 10 to 180 minutes, and all temperatures Method for performing rotary drying or vacuum rotary drying in the range or raising the temperature from 0 to 60 ° C. to 70 to 250 ° C. for 100 to 180 minutes, maintaining this temperature for 10 to 80 minutes, for all temperature ranges Particular preference is given to using methods of carrying out rotary drying or vacuum rotary drying. First of all, preferred examples of the above-mentioned drying step include drying at 40 ° C. for 2 hours, then raising the temperature to 100 ° C. over 40 minutes, and then holding at 100 ° C. for 30 minutes, in all these temperature ranges. Method of using a rotary drying method or a vacuum drying method, and a rotary drying method or a vacuum rotation in all temperature ranges while increasing the temperature from 40 ° C to 100 ° C for 2 hours and 30 minutes, and maintaining the temperature at 100 ° C for 30 minutes. It includes a method of performing a drying method.

It is also preferable to calcinate the catalyst at the above-mentioned temperatures, for example at high temperatures of 250 to 350 ° C or higher. If the calcination temperature is out of the above-mentioned range, enzymatic activity sometimes becomes insufficient. In the present invention, no limitation is placed on the atmosphere upon calcination, but can generally be carried out in air. In such a case, calcination can be carried out under an air stream, or even if no air flow is present.

The halogen-containing catalyst according to the present invention contains the above-mentioned L-type zeolite, but if necessary, natural or synthetic inorganic oxides such as alumina, silica or aluminosilicate can be added as a binder. The amount of binder used is preferably 5 to 90% based on the total weight of the catalyst.

Examples of hydrocarbons as raw materials to which the halogen-containing catalyst of the present invention can be applied include paraffin hydrocarbons, olefin hydrocarbons, acetylene hydrocarbons, cycloparaffin hydrocarbons, and cycloolefin hydrocarbons, which can be used in the form of a single or two or more mixtures.

The above-mentioned paraffinic hydrocarbons preferably have 6 to 10 carbon atoms, and general examples of paraffinic hydrocarbons include n-hexane, methylpentane, n-pentane, methylhexane, dimethylpentane, and n-octane.

In addition, the above-mentioned olefin hydrocarbons preferably have 6 to 10 carbon atoms, and examples of general olefin hydrocarbons include hexene, methylpentene, heptene, methyl hexene, dimethylpentene and octene. The above-mentioned acetylene hydrocarbons preferably have 6 to 10 carbon atoms, and examples of typical acetylene hydrocarbons include hexine, heptin, and octin.

The above-mentioned cycloparaffinic hydrocarbons preferably have 6 to 10 carbon atoms, and examples of typical cycloparaffinic hydrocarbons include methylcyclopentene, cyclohexene, methylcyclohexene, and dimethylcyclohexene.

In addition, the above-mentioned cycloolefin hydrocarbons preferably have 6 to 10 carbon atoms, and examples of general cycloolefin hydrocarbons include methylcyclopentene, cyclohexene, methylcyclohexene, and dimethylcyclohexene.

As mentioned above, in the halogen-containing catalyst of the present invention, it is possible to make the distribution of halogen content in the catalyst constant by slowing the water evaporation rate in the drying step of the manufacturing process, and as a result, metals such as platinum are widely diffused and cracked. Lowers selectivity and increases aromatic selectivity; Therefore, the cracking activity can be regulated.

The present invention will be described in more detail with reference to Examples and Comparative Examples.

The present invention has been developed under such circumstances. That is, it is an object of the present invention to provide a catalyst which is uniform in the distribution of halogen amount in the catalyst, so that the cracking activity can be reduced, and is used for the production of aromatic hydrocarbons.

Another object of the present invention is to provide a process for preparing the above-mentioned catalyst.

The present inventors have been intensively researched with the intention to develop a practical catalyst that reduces the cracking activity mentioned above as a catalyst for producing an aromatic compound, and as a result, moisture in the drying step during catalyst preparation. It was found that when the evaporation rate is slow, a catalyst having a uniform distribution of halogen content in the catalyst can be obtained, thereby effectively achieving the object of the present invention. The present invention has been completed based on such knowledge.

That is, the primary aspect of the present invention relates to a halogen-containing catalyst containing at least one halogen component and having a uniform distribution of halogen content in the catalyst. In particular, halogen atoms on the cross section of the catalyst are referred to as an electron probe microanalysis apparatus (hereinafter referred to as EPMA). In the figure showing the relationship between the cross-sectional widthwise direction (x: distance from one catalyst surface) and X-ray intensity (I) obtained by performing linear analytical measurement in one direction, from one catalyst surface Curve for the minimum and minimum values of the X-ray intensity plot of x from the integral value F of x with respect to x between the other catalyst surface and the catalyst surface from one catalyst surface to the other The present invention relates to a halogen-containing catalyst having a ratio α [(FF ₀ ) / F] obtained by subtracting the integral value (F ₀ ) of the X-ray intensity I ₀ , which is a tangent of, from the integral value F.

Another aspect of the present invention provides a process for preparing a halogen-containing catalyst comprising the step of immobilizing at least one halogen component on a carrier, in particular on an L-type zeolite and subsequently drying at a water evaporation rate of up to 15% by weight per hour. It is about a method.

Example 1

(1) Preparation of Catalyst

20 parts by weight of silica binder (Snowtex, manufactured by Nissan Chemical Co., Ltd.) is added to 100 parts by weight of L-type zeolite (TSZ-500KOA, manufactured by Tosoh Corporation), followed by mixing and casting. Thereafter, calcination at 500 ° C. for 2 hours in air is carried out to obtain a cast silica L-type zeolite.

A saturated solution is prepared by mixing 0.086 g of tetrachloride platinum, 0.088 g of ammonium fluoride, 0.019 g of ammonium chloride, and 2.1 g of ion-exchanged water. The saturated solution thus prepared is slowly added dropwise to the above-mentioned cast L-type zeolite having a silica binder which fixes platinum and halogen. In the drying step, the initial vacuum drying is carried out at 40 ℃ for 2 hours, then the temperature is raised to 100 ℃ over 40 minutes in the vacuum rotating conditions, and vacuum drying drying for 30 minutes at 100 ℃. In addition, the vacuum degree in vacuum rotation drying is 40 Torr. Calcination is then carried out in air at 320 ° C. for 1 hour to produce a catalyst.

Comparative Example 1

(1) Preparation of Catalyst

5 g of L-type zeolite carried out to the fixing step of Example 1 was heated to room temperature to 100 DEG C over 60 minutes under vacuum rotary drying conditions, and maintained at 100 DEG C for 3 hours under vacuum rotary drying conditions. The same procedure as in Example 1 was carried out except for the drying step. In addition, the vacuum degree in vacuum rotation drying is 40 Torr.

Example 2

(1) Preparation of Catalyst

5 g of the L-type zeolite carried out in the fixing and processing steps in Example 1 was heated over 40 minutes to 40 ° C. to 100 ° C. under vacuum rotary drying conditions, and maintained at 100 ° C. for 30 minutes under vacuum rotary drying conditions. The same method as in Example 1 was carried out except for the drying step. In addition, the vacuum degree in vacuum rotary drying is 40 Torr.

Example 3

(1) Preparation of Catalyst

5 g of the L-type zeolite carried out in the fixing and treating steps in Example 1 was heated at room temperature to 90 ° C. while rotating at atmospheric pressure for 2 hours, and then maintained at 90 ° C. for 3 hours under atmospheric rotation conditions. It is carried out in the same manner as in Example 1 except for the drying step.

Example 4

(1) Preparation of Catalyst

5 g of the L-type zeolite carried out in the fixing and processing steps in Example 1 was heated to 40 ° C. to 100 ° C. over 100 minutes under vacuum rotation drying conditions, and then maintained at 100 ° C. for 30 minutes under vacuum rotation drying conditions. do. It is carried out in the same manner as in Example 1 except for the drying step. In addition, the vacuum degree in vacuum rotation drying is 40 Torr.

Example 5

(1) Preparation of Catalyst

5 g of the L-type zeolite carried out in the fixing and processing steps in Example 1 was heated for 3 hours while rotating at room temperature to 90 ° C. under atmospheric pressure, and then maintained at 90 ° C. for 3 hours under atmospheric rotation conditions. The same method as in Example 1 was carried out except for the drying step.

(2) Evaluation of Catalyst Characteristics

Measurement of moisture content

In the above-mentioned examples and comparative examples, the catalyst was precipitated during drying, and the water content was measured by TG-DTA. The 10 mg catalyst was weighed while the catalyst was in the form of castings and then mounted in the apparatus. The temperature was raised from room temperature to 1000 ° C. under 70 cc / min airflow. The temperature rise rate was 20 ° C / min. The mass of catalyst decreased until reaching 500 ° C. was regarded as water content and the evaporation rate was calculated. The results are shown in Table 1.

EPMA Measurement

Each catalyst obtained above was captured in resin (PMMA: polymethyl methacrylate), and the resin containing the catalyst was cut parallel to the bottom surface to expose the measurement surface as shown in FIG. Using a general EPMA apparatus, alpha values were measured at 15 kV acceleration voltage, 1 μm beam size, and 0.05 mA sample current. The results are shown in Table 1.

Evaluation of pulse response

Each catalyst obtained is filled with 32 to 65 mesh and 50 mg of the filled catalyst is filled into the reactor after weighing. After the reactor was mounted in the apparatus, the temperature was raised to 540 ° C. over 35 minutes at 100 cc / min hydrogen flow rate, and hydrogen reduction was performed at 540 ° C. for 1 hour. After performing hydrogen reduction, the temperature is maintained at 460 ° C. NC ₆ was used as the reaction material. Pulse size was varied by 0.5 μL, 1.0 μL, 2.0 μL and 3.0 μL to change the conversion. The results are shown in Table 1. Lower C _1-4 selectivity is better catalyst. In addition, C _1-4 selectivity for each product was calculated as follows.

C _1-4 selectivity = [C _1-4 weight / (C _1-5 + benzene) weight] × 100

Water evaporation rate (wt% / hour) EPMA measurement C1 distribution (α) C _1-4 selectivity (wt%) at 60 wt% benzene yield Example 1 6 0.12 3.0 Comparative Example 1 30 0.20 10.5 Example 2 6 0.12 3.0 Example 3 15 0.17 5.5 Example 4 15 0.15 5.0 Example 5 4 0.06 2.5

Therefore, the halogen-containing catalyst of the present invention and its preparation method can be widely and effectively used in the petrochemical industry for producing aromatic hydrocarbons and the petroleum industry for producing high octane fuel and similar industries.

Claims (11)

Halogen-containing catalyst comprising at least one halogen component and having a uniform distribution of halogen amounts in the catalyst. The cross section widthwise direction distance (x: distance from one catalyst surface) obtained by performing linear analytical measurements of halogen atoms on a catalyst cross section in one direction using an electron probe microanalysis (EPMA) apparatus; In the figure showing the relationship between the X-ray intensity (I), from the integral value (F) of I to x between one catalyst surface and the other catalyst surface, from the other catalyst surface to the other catalyst surface The ratio between the integrated value F and the ratio α [(FF ₀ ) minus the integral value (F ₀ ) of the X-ray intensity I _{0 which} is the tangent of the curve for the minimum and minimum values of the curve representing the X-ray intensity with respect to x / F] is a halogen-containing catalyst having 0.17 or less. The halogen-containing catalyst according to claim 1 or 2, which contains platinum and at least one halogen component immobilized on the L-type zeolite. A process for producing aromatic hydrocarbons from non-aromatic hydrocarbons using the halogen-containing catalysts described in claim 1. Fixing at least one halogen component on a carrier, followed by drying at a water evaporation rate of up to 15% by weight per hour. Fixing at least one halogen component and at least one metal on a carrier, followed by drying at a water evaporation rate of up to 15% by weight per hour. A method for preparing a halogen-containing catalyst comprising the step of immobilizing at least one halogen component and platinum on an L-type zeolite, followed by drying at a water evaporation rate of up to 15% by weight per hour. 8. Process according to any one of claims 5 to 7, wherein the rate of water evaporation is up to 10% by weight per hour. The process according to any one of claims 5 to 8, wherein drying is carried out at a low temperature, followed by drying at a high temperature. 10. The process according to claim 5, wherein the halogen-containing catalyst is subjected to vacuum drying. A method for preparing a halogen-containing catalyst comprising the step of fixing at least one halogen component to a carrier, drying at a water evaporation rate of 15% by weight or less per hour and then fixing platinum thereto.