JP3167376B2 - Catalyst for producing aromatic hydrocarbon, method for producing the same, and method for producing aromatic hydrocarbon using the catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst for the production of aromatic hydrocarbons, and more particularly, to a method for producing a raw material mainly composed of an aliphatic hydrocarbon having 2 to 7 carbon atoms and / or an alicyclic hydrocarbon. TECHNICAL FIELD The present invention relates to a catalyst for converting into a catalyst, a method for producing the catalyst, and a method for producing an aromatic hydrocarbon using the catalyst.

[0002]

2. Description of the Related Art In a method of converting an aliphatic hydrocarbon and / or an alicyclic hydrocarbon into an aromatic hydrocarbon using a crystalline aluminozincosilicate catalyst, a catalyst is prepared by supporting a transition metal on a crystalline aluminozincosilicate. It has been proposed to increase the activity (see, for example, JP-A-63-8342).
JP-A-3-99025). However, the catalyst supporting the transition metal has a problem that the supported metal is aggregated during use and the effect of improving the catalytic activity cannot be maintained for a long time.In addition, when zinc is used as the supported metal, the catalyst is used. During this process, there is a problem that zinc is volatilized and is lost, and the catalytic activity is reduced.

[0003]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that zinc is converted into a composite oxide with aluminum or silicon and mixed with crystalline aluminodine cosilicate. The present inventors have found that zinc agglomeration and loss can be prevented and the activity of the catalyst can be improved.

An object of the present invention is to provide a catalyst for producing an aromatic hydrocarbon which has a higher catalytic activity and which can maintain the activity for a long time, a method for producing the same, and a C2-7 catalyst using the same. An object of the present invention is to provide a method for efficiently converting an aliphatic hydrocarbon and / or an alicyclic hydrocarbon into an aromatic hydrocarbon.

[0005]

According to the present invention, the atomic ratio of Si / Al is 14-1000 and the atomic ratio of Si / Zn is 15-100.
0 for the production of aromatic hydrocarbons containing a crystalline aluminozincosilicate having an alkali metal content of 0.4% by weight or less and a composite oxide of zinc and aluminum or a composite oxide of zinc and silicon A catalyst, a zinc compound and an aluminum compound, or a zinc compound and a silicon compound are mixed and calcined at a temperature of 300 ° C. or higher to obtain a zinc-aluminum composite oxide or a zinc-silicon composite oxide. Si / Al atomic ratio is 14-1000,
A method for producing a catalyst for producing an aromatic hydrocarbon, which comprises mixing with a crystalline aluminodine cosilicate having an Si / Zn atomic ratio of 15 to 1000 and an alkali metal content of 0.4% by weight or less, and carbon number At least 50% by weight of 2 to 7 aliphatic hydrocarbons and / or alicyclic hydrocarbons
This is a method for producing an aromatic hydrocarbon, which comprises contacting a contained raw material with the catalyst.

The above Si / Al atomic ratio is 14-1000,
The crystalline aluminozincosilicate having an Si / Zn atomic ratio of 15 to 1000 and an alkali metal content of 0.4% by weight or less is an alkali metal ion of the crystalline aluminozincosilicate having the above atomic ratio, particularly a sodium ion. Can be prepared by immersing a crystalline aluminozincosilicate in an aqueous solution of nitric acid, hydrochloric acid, sulfuric acid or ammonium salt, and calcining the material after exchanging for hydrogen ions or ammonium ions. Prior to this exchange, the crystalline aluminozincosilicate may be calcined, for example, at 540 ° C. in air. In these ion exchanges, an operation of immersing in an aqueous solution to remove gas by heating, decompression, or the like may be added. Further, one obtained by exchanging most of the alkali metal ions of the aluminozincosilicate with alkaline earth metal ions can also be used.

[0007] Thus, the alkali metal content is made 0.4 wt% or less, more preferably 0.1 wt% or less. If the content of alkali metal, especially sodium, in the crystalline aluminodine silicate exceeds 0.4% by weight, the catalyst life is shortened.

On the other hand, crystalline aluminosilicate is a substance obtained by partially substituting aluminum in aluminosilicate with zinc. Silicon, aluminum and zinc atoms share oxygen to crosslink, and have the same skeletal structure as crystalline aluminosilicate. It has. In this case, all of the silicon, aluminum and zinc atoms do not always constitute the same crystal structure, and some of them may coexist in another form such as a respective oxide.

[0009] This crystalline aluminodine cosilicate is
A silicon compound, an aluminum compound, a zinc compound, an alkali metal salt, water, and optionally an organic nitrogen compound and an acid are mixed, and the mixture is mixed at a temperature of 100 ° C to 220 ° C for 3 to 200 minutes.
It can be prepared with keeping time. In this case, as the silicon compound, sodium silicate, potassium silicate, silica, or a mixture of two or more of these 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 of these can be used. As the zinc compound, zinc sulfate, zinc nitrate, zinc chloride, zinc oxide, zinc hydroxide, or a mixture of two or more of these can be used. Alkali metal salts include sodium and potassium hydroxide, chloride, bromide, sulfate, nitrate, acetate,
Alternatively, a mixture of two or more of these can be used. As organic nitrogen compounds, tetrapropylammonium, tetrabutylammonium, quaternary ammonium hydroxides such as tripropylmethylammonium, bromide, chloride, or tripropylamine, tributylamine, amines such as morpholine, triethanolamine, Amino alcohols such as diethanolamine, amides such as acetamide and propionamide, alkyl ureas such as methyl urea and 1,3-dimethyl urea, nitriles such as acetonitrile and propionitrile, and mixtures of two or more of these can be used. . As the acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, phosphoric acid, or a mixture of two or more thereof can be used. These raw materials do not need to be used alone, and may be in a pre-mixed state such as silica alumina or a compound. The raw materials are not limited to those exemplified here.

As the crystalline aluminozincosilicate of the present invention, those having an atomic ratio of Si / Al of 14 to 1000 and an atomic ratio of Si / Zn of 15 to 1000 are used. This is because if the atomic ratio of Si / Al is less than 14, it is difficult to form a crystal with slow deterioration of the catalyst performance over time, whereas if the atomic ratio is more than 1000, the activity of the catalyst is not sufficient and the deterioration with time is accelerated. That's why. The atomic ratio of Si / Zn is 1
If it is less than 5, crystal formation is poor and the catalyst deteriorates with time, and if it is more than 1,000, the selectivity of aromatics is low.

It is preferable to use the crystalline aluminodine cosilicate having an X-ray diffraction pattern shown in Table 1 similar to the ZSM-5 type zeolite.

[Table 1]

The catalyst of the present invention is obtained by adding a composite oxide of zinc and aluminum or a composite oxide of zinc and silicon to the above crystalline aluminodine cosilicate.
This zinc-aluminum composite oxide or zinc-silicon composite oxide is unlikely to form metallic zinc even when exposed to a reducing gas because zinc is very well dispersed in the composite oxide, and may cause agglomeration. There is little risk of zinc loss due to volatilization. For this reason, it is a catalyst with increased zinc which is stable and has high dehydrogenation catalytic activity. It is thought that the zinc-aluminum composite oxide and the zinc-silicon composite oxide have an acid property in addition to dehydrogenation. Significantly promotes the conversion of hydrogen to aromatic hydrocarbons.

The composite oxide of zinc and aluminum can be prepared by a common coprecipitation method, an adsorption method, a dry method, or the like. The coprecipitation method involves mixing a solution containing zinc and a solution containing aluminum, or adding an alkali or acid to a solution containing both zinc and aluminum to obtain a coprecipitate such as a hydroxide of zinc and aluminum. The adsorption method is a method in which a solution containing one of zinc and aluminum and the other oxide are added, mixed, dried, and fired. In addition, the dry method is a method in which zinc oxide and aluminum oxide are mixed in a dry or wet manner and fired.

[0014] In each of the above cases, firing is performed at a temperature of 300 ° C or higher. If the temperature is lower than 300 ° C., a composite oxide is not easily generated.

The zinc raw materials used in these methods include zinc nitrate, zinc sulfate, zinc chloride, zinc acetate, zinc hydroxide,
Examples thereof include zinc oxide, zinc aluminum sulfate, and sodium zincate. Examples of the aluminum compound include aluminum nitrate, aluminum sulfate, aluminum chloride, aluminum acetate, sodium aluminate, aluminum hydroxide, aluminum oxide, aluminum isopropoxide, and aluminum ethoxide.

The atomic ratio of zinc to aluminum in the composite oxide of zinc and aluminum is preferably in the range of 0.01 to 10, preferably 0.1 to 1. When the atomic ratio is less than 0.01, the effect of increasing the catalytic activity is small,
If it is larger than 10, zinc tends to volatilize, which is not preferable.

The composite oxide of zinc and silicon can be prepared by a coprecipitation method, an adsorption method, a dry method or the like in the same manner as described above. In this case, the same zinc compound as in the case of the composite oxide of zinc and aluminum can be used as the zinc raw material. Further, as a silicon raw material, sodium silicate, potassium silicate, silicon oxide, colloidal silica,
Tetraethoxysilane or the like can be used.

The atomic ratio of zinc to silicon is 0.01
-10, preferably 0.1-2. When the atomic ratio is less than 0.01, the effect of increasing the catalytic activity is small, and when the atomic ratio is greater than 10, zinc is easily volatilized,
Not preferred.

The composite oxide of zinc and aluminum or the composite oxide of zinc and silicon is mixed with a crystalline aluminozincosilicate and used as a catalyst. The content of the composite oxide of zinc and aluminum or the composite oxide of zinc and silicon in the entire catalyst is desirably 0.1 to 70% by weight, preferably 1 to 30% by weight. In this case, when the content of these composite oxides is 0.1% by weight or less, the effect of addition is poor, and when the content is 70% by weight or more, the catalytic activity decreases.

The composite oxide and the crystalline aluminodicosilicate can be used as a catalyst in a state of being simply mixed as they are, or even when molded. For this molding,
What is generally used as a granulating agent, such as silica, alumina, granular soil, inorganic salts, organic polymers, and surfactants, can be used.

In the production of the catalyst, the order of the steps of ion exchange and calcination of the crystalline aluminozincosilicate, mixing of the composite oxide with the crystalline aluminozincosilicate, and molding are not particularly limited.

The catalyst produced by the above method has 2 carbon atoms.
Used as a catalyst for producing an aromatic hydrocarbon from an aliphatic hydrocarbon and / or an alicyclic hydrocarbon having from 7 to 7 carbon atoms, such as ethane, propane, n-butane, Saturated hydrocarbons such as iso-butane, n-pentane, iso-pentane, neopentane, n-hexane, methylpentane, dimethylbutane, n-heptane, methylhexane, dimethylpentane, ethylene, propylene, butene, butadiene, pentene, pentadiene , Hexene, hexadiene, heptene, heptadiene, cyclopentene, methylcyclopentene, cyclohexene,
Examples include unsaturated hydrocarbons such as methylcyclohexene, cycloheptene, cyclohexadiene, and methylcyclohexadiene.

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

The raw materials supplied to the reaction are those having 2 to 2 carbon atoms as described above.
7, containing at least 50% by weight of an aliphatic hydrocarbon and / or an alicyclic hydrocarbon of component 7,
For example, benzene, toluene, hydrocarbons having 8 or more carbon atoms,
Even if methanol, dimethyl ether or the like is mixed, it does not matter.

The aromatization reaction is suitably carried out in a temperature range of 350 to 600 ° C. If the reaction temperature is lower than 350 ° C., the yield of aromatic hydrocarbon is not sufficient,
If the temperature is higher than ℃, the catalyst performance is rapidly degraded due to coke formation.
The feed rate of the raw material composition of the feed, the reaction temperature, depending on the type of catalyst, the weight hourly space velocity (WHSV) is suitably in the range of 0.1 to 10 ^-1. A WHSV of 0.1 hr ^-1 smaller than aromatic low production efficiency of hydrocarbons, whereas, is not sufficient yield 10 hr ^-1 larger than aromatic hydrocarbons.

The pressure for the aromatization reaction is suitably from 0 to 50 kg / cm ² · G. At a pressure of 50 kg / cm ² · G or more, the yield of aromatic hydrocarbon is not high. 2 to 2 carbon atoms as reaction raw materials
The aliphatic hydrocarbon of No. 7 may be supplied as it is, or may be supplied together with hydrogen, nitrogen and carbon dioxide.

[0027]

【Example】Example 1  [Preparation of catalyst] 26 ml of sodium chloride was added to 104 ml of distilled water.
g, dissolve 1.9 g of tetrapropylammonium bromide
1.34 g of zinc sulfate in 60 ml of distilled water and sulfuric acid
1.71 g of luminium, tetrapropylammonium bromide
Liquid A containing 5.6 g of amide and 5.3 g of concentrated sulfuric acid, and 4 parts of distilled water
While stirring solution B in which 69 g of No. 3 water glass was dissolved in 5 ml,
Were added simultaneously and continuously. At that time, the pH of the mixture
Sodium hydroxide or sulfuric acid so that it is maintained at 10.
In addition, it was adjusted. Collect the gel from this mixture by centrifugation
For 1 hour and combined with the supernatant by centrifugation.
Transfer the mixture to an autoclave and reach 160 ° C in 3 hours
The temperature is raised and maintained at 160 ° C. for 20 hours with stirring.
Was. The solid was taken out by cooling, washed with water and dried. this
Is referred to as A. This A was calcined at 540 ° C.
Aluminosinus with lattice spacing by X-ray diffraction
A silicate was obtained.

5 g of A was immersed in 250 ml of a 1N aqueous ammonium nitrate solution, stirred at 80 ° C. for 2 hours to remove the supernatant, washed with water, dried, calcined at 540 ° C., immersed again in an aqueous ammonium nitrate solution, washed with water, Dried and fired. This is called B.

Next, a composite oxide of zinc and aluminum was prepared as follows. That is, 74 g of zinc nitrate hexahydrate and 188 g of aluminum nitrate nonahydrate were added to 350 ml of water.
And aqueous ammonia was added thereto while stirring to adjust the pH to 7, and zinc hydroxide and aluminum hydroxide were coprecipitated. The precipitate is collected by centrifugation, washed with water,
After drying at 500C, the mixture was calcined at 500C for 2 hours to obtain 45 g of a composite oxide. This is called C. Zn / Al of this C
The ratio was 0.22.

A composite oxide of zinc and silicon was prepared as follows. That is, the silicon content is 28 in terms of SiO _2.
A solution of 63 g of zinc nitrate hexahydrate and 100 ml of water was added with stirring to a solution obtained by adding 100 ml of water to 126 g of an aqueous sodium silicate solution containing weight percent, and a nitric acid solution was added to adjust the pH to 7, and silicon hydroxide and water were added. Zinc oxide was co-precipitated. After collecting the precipitate by centrifugation and washing with water,
After drying at a temperature of 110 ° C., the mixture was calcined at 500 ° C. for 2 hours to obtain 43 g of a composite oxide D. Its Zn / Si ratio is 0.1
It was 6.

[Aromatization reaction] 2 g of a catalyst in which 90% by weight of B and 10% by weight of C were mixed in a mortar was charged into a reactor having a diameter of 10 mm, the catalyst bed temperature was set at 525 ° C, and the pressure was 3 kg / kg. c
At m ² · G, aromatization reaction was carried out by flowing n-pentane at a feed rate of 2 g / h. The reactor outlet gas was sampled and its composition was analyzed by gas chromatography.
-The pentane conversion and the aromatic selectivity were calculated by the following equations.

Embedded image

Table 1 shows n-pentane conversion and aromatic selectivity at 1 hour, 100 hours and 200 hours after the start of the raw material distribution.

[0033]Example 2  90% by weight of B and 10% by weight of D mixed in a mortar
2 g of n-pentane in the same manner as in Example 1 except for using 2 g of a medium.
An aromatization reaction was performed. N-pentane conversion of the result
Table 2 shows the selectivity and the aromatic selectivity.

[0034]Example 3  Catalyst in which 90% by weight of B and 5% by weight of C are mixed in a mortar
Using 2 g, catalyst bed temperature of 525 ° C., 0 kg / cm^Two・ G pressure
Force, n-pentane feed rate 4 g / h, others as in Example 1
The aromatization reaction was performed under the conditions. The resulting n-penta
Table 3 shows the conversion and the aromatic selectivity.

[0035]Comparative Example 1  Except that 2 g of B was used as the catalyst, n-pe
The aromatization reaction of tin was performed. The resulting n-pen
Table 2 shows the tan conversion and the aromatic selectivity.

[0036]Comparative Example 2  The same procedure as in Example 1 was repeated except that 2 g of C was used as the catalyst.
The aromatization reaction of tin was performed. The resulting n-pen
Table 2 shows the tan conversion and the aromatic selectivity.

[0037]Comparative Example 3  Except that 2 g of D was used as a catalyst, n-pe
The aromatization reaction of tin was performed. The resulting n-pen
Table 2 shows the tan conversion and the aromatic selectivity.

[Table 2]

[0038]Comparative Example 4  Except that 2 g of B was used as the catalyst, n-pe
The aromatization reaction of tin was performed. The resulting n-pen
Table 3 shows the tan conversion and the aromatic selectivity.

[Table 3]

[0039]Example 4  Light naphtha having the composition shown in Table 4 as a reaction raw material
The aromatization reaction was carried out in the same manner as in Example 1 except that
Was. The conversion and the aromatic yield were determined by the following equations.

[Table 4]

The conversion after one hour from the start of the raw material distribution is 100
%, Aromatic selectivity is 50% by weight, 99% after 100 hours, 47% by weight, and 98 hours after 200 hours.
%, 45 wt%.

[0041]

According to the present invention, an aromatic hydrocarbon can be obtained from an aliphatic hydrocarbon and / or an alicyclic hydrocarbon with a high conversion and an aromatic selectivity by using the catalyst of the present invention as described above. In addition, since the catalyst activity can be maintained for a long time, the catalyst life is extremely long, and there is a special effect that an aromatic hydrocarbon can be produced industrially advantageously.

Continuation of front page (56) References JP-A-4-95034 (JP, A) JP-A-3-178934 (JP, A) JP-A-1-226833 (JP, A) JP-A-2-258618 (JP) , A) JP-A-48-83092 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01J 21/00-38/74 C07C 2/42 C07C 15/00

Claims (3)

(57) [Claims] 1. The method according to claim 1, wherein the Si / Al atomic ratio is 14 to 1000,
A crystalline aluminozincosilicate having an i / Zn atomic ratio of 15 to 1000 and an alkali metal content of 0.4% by weight or less, and a composite oxide of zinc and aluminum or a composite oxide of zinc and silicon. A catalyst for the production of aromatic hydrocarbons. 2. A zinc compound and an aluminum compound, or a zinc compound and a silicon compound are mixed and fired at a temperature of 300 ° C. or more to obtain a zinc-aluminum composite oxide or a zinc-silicon composite oxide. This is Si / A
l atomic ratio is 14-1000, Si / Zn atomic ratio is 15-
A method for producing a catalyst for producing aromatic hydrocarbons, which comprises mixing with a crystalline aluminozincosilicate having a weight of 1000 and an alkali metal content of 0.4% by weight or less. 3. An aromatic material, comprising contacting a raw material containing at least 50% by weight of an aliphatic hydrocarbon and / or an alicyclic hydrocarbon having 2 to 7 carbon atoms with the catalyst according to claim 1. A method for producing hydrocarbons. [0001]