JPH06199B2 - Preparation method of catalyst loaded with alkali metal - Google Patents

Description

Description: TECHNICAL FIELD The present invention is effective for various reactions caused by a base catalyst in which a powder of an anhydrous potassium compound is loaded with an alkali metal by a specific method. The present invention relates to a method for preparing a catalyst having a catalytic action.

[Conventional technology]

As a conventional preparation method in which an alkali metal is supported on a potassium compound, for example, British Patent Specification No. 1269280,
Japanese Examined Patent Publication No. Sho 42-22474 discloses a method of depositing and supporting sodium on potassium carbonate, or using an inert gas atmosphere.
A method for mixing and supporting sodium melted at 150 to 400 ° C. is described. These conventional methods generally require a special preparation device for melting or vapor-depositing an alkali metal at a high temperature, and the operation is complicated, and in the obtained catalyst, the dispersion of the alkali metal on the carrier is uneven and uneven. This is sufficient, and the exchange rate between the alkali metal and potassium derived from the carrier is low, which causes problems such as low activity as a catalyst.

[Problems to be solved by the invention]

The inventors of the present invention have found that the conventional method for preparing a catalyst in which an alkali metal is supported on a potassium compound has the above-mentioned problems, and therefore, in order to improve this, a simple method as compared with the conventional method can be used. A method for preparing a highly active catalyst was examined.

[Means / Action for Solving the Invention]

As a result, they have found that the above object can be achieved by adopting the following method, and completed the present invention. That is, according to the method of the present invention, powders of an alkali metal and an anhydrous potassium compound are mixed at a temperature equal to or higher than the melting point of the alkali metal in a liquid hydrocarbon catalyst inert to the alkali metal. Provided is a method for preparing a catalyst in which an alkali metal is supported on an anhydrous potassium compound powder.

In the present invention, an alkali metal is supported on a powder of an anhydrous potassium compound as a carrier by a specific method described later.
Specific examples of the anhydrous potassium compound in this case include anhydrous carbonates of inorganic potassium compounds such as potassium carbonate, potassium silicate, potassium sulfate, potassium fluoride, potassium chloride, potassium bromide and potassium phosphate. . Among these anhydrous potassium compounds, anhydrous potassium carbonate is particularly suitable. The alkali metal is lithium, sodium, potassium, rubidium, cesium or the like, of which sodium is preferred.

With respect to the powder of the anhydrous potassium compound used in the present invention, the powder of the compound obtained by a conventionally known ordinary method can be used. In the present invention, it is not particularly necessary to use powders of anhydrous potassium compounds having different physical properties, and powders of anhydrous potassium compounds having appropriate physical properties according to the type of reaction intended by the catalyst. Can be used. As an example of this case, when the catalyst of the present invention, for example, a catalyst obtained by supporting an alkali metal on a powder of potassium carbonate is used in a reaction for side chain alkylation of an alkyl-substituted aromatic hydrocarbon with an aliphatic monoolefin, It is preferable to use a powder of potassium carbonate having the following physical properties because the activity becomes particularly high. That is, the bulk density is usually 0.85 g / cm ³
Below, the average particle size is usually 100 to 800μ and the powder weight in the range of 100 to 800μ is usually 60 of the total powder weight.
It is preferable to use a potassium carbonate powder that accounts for at least 100% because the yield of the side chain alkylation reaction product is high.

In the present invention, the powder of the above-mentioned anhydrous potassium compound and the alkyl metal are mixed at a temperature not lower than the melting point of the alkali metal in a liquid hydrocarbon catalyst inert to the alkali metal to give an alkali metal to the powder. A catalyst on which is supported is prepared. Specific examples of the liquid hydrocarbon catalyst inert to the alkali metal in this case include benzene, toluene, ethylbenzene, isopropylbenzene, xylene, mesitylene, and other aromatic hydrocarbons substituted with an alkyl group, and hexane and heptane. , Octane, decane, dodecane, tridecane, and other saturated aliphatic hydrocarbons and tetralin, decalin, cyclohexane and other alicyclic hydrocarbons can be exemplified, but in the present invention, among these, toluene,
It is preferable to use xylene, hexane, n-octane, and n-decane. In the present invention, the hydrocarbon catalyst may be used alone, or may be mixed and used if necessary. In the present invention, with respect to the ratio of the powder of the anhydrous potassium compound and the alkali metal used in preparing the catalyst, the alkali metal is usually 0.5 to 10 parts by weight, preferably 100 parts by weight of the powder, preferably Is 1 to 7 parts by weight. When the amount of the alkali metal is 0.5 parts by weight or less, the activity of the catalyst is low with respect to the reaction to which the catalyst of the present invention described below is applied, and when it is 10 parts by weight or more, uniform loading is difficult. Not only the high boiling point substance is by-produced during the reaction to which the catalyst of the present invention described below is applied to poison the catalyst, and in an extreme case, a pit-like solid substance is generated and the reactor is blocked. It is not preferable because it causes trouble. The ratio of the hydrocarbon catalyst used in the present invention is usually 100 to 1000 parts by weight, preferably 150 to 500 parts by weight, based on 100 parts by weight of the anhydrous potassium compound powder.

In the present invention, the powder of the alkali metal and the anhydrous potassium compound is mixed in the hydrocarbon catalyst at a temperature equal to or higher than the melting point of the alkali metal to allow the alkali metal to be supported on the powder of the anhydrous potassium compound. However, the temperature in this case is usually 120 to 2
It is 50 ° C, preferably 150 to 230 ° C. The temperature is 120
When the temperature is lower than 0 ° C, a highly active catalyst cannot be obtained because the interaction between the potassium ion and the alkali metal and the exchange reaction between the potassium derived from the potassium compound and the alkali metal to be supported, such as sodium, are unlikely to occur. Not preferable. If the temperature is 250 ° C or higher,
When toluene, ethylbenzene, xylene or the like is used as a hydrocarbon catalyst, a coupling reaction or the like occurs at the time of catalyst preparation, and the catalyst is poisoned and loses its activity. Also in the case of saturated hydrocarbons, a large amount of metallic potassium is by-produced,
It is not preferable because a pit-like solid substance is formed during the reaction.

In the present invention, the catalyst obtained by supporting the alkali metal on the powder of the anhydrous potassium compound by the above method is then removed from the hydrocarbon catalyst and subjected to the reaction in an inert gas atmosphere containing no water. It may be stored until it is stored, or may be stored as it is in the dispersion medium containing no water.

The catalyst obtained by the method of the present invention described above, the powder of the anhydrous potassium compound of the carrier is usually 0.5 to 10 wt% alkali metal not derived from the potassium carbonate based on the carrier,
The amount is preferably 1 to 7% by weight.

According to the method of the present invention, a catalyst having a high activity for the reaction described below can be obtained by a simple method at a relatively low temperature as compared with the conventional method.

In the present invention, the catalyst prepared by the above-mentioned method is, for example, an alkyl-substituted aromatic hydrocarbon in which an alkyl-substituted aromatic hydrocarbon is reacted with an aliphatic monoolefin to increase the number of carbon atoms by a side-chain alkylation reaction. To obtain alkenylbenzene by reacting alkylbenzene with a conjugated diene, dimerization and codimerization of lower olefins, isomerization reaction of olefins, dehydrogenation reaction, hydrogenation reaction, reduction of conjugated dienes It can be used as a catalyst for various reactions caused by conventionally known base catalysts such as polymerization reaction, addition reaction, transesterification reaction and various condensation reactions. As a specific example of the reaction in this case, for example, a catalyst obtained by carrying out the method of the present invention on which an alkali metal is supported on a potassium carbonate powder is excellent when used in the side chain alkylation reaction. Shows the catalytic action of toluene, ethylbenzene,
Alkyl-substituted aromatic hydrocarbons such as xylene are reacted with aliphatic monoolefins such as ethylene, propylene and butene to produce n-propylbenzene, isobutylbenzene,
sec-Putylbenzene, amyltoluene, etc. can be obtained in high yield.

Further, similarly, regarding the production of the alkenylbenzenes, for example, toluene, xylene, ethylbenzene, trimethylbenzene, and methylnaphthalene are substituted with alkyl-substituted aromatic hydrocarbons such as 1,3-butadiene, 1,3-pentadiene,
By reacting with isoprene or 1,3-hexadiene
It is possible to obtain n-pentenylbenzene, n-pentenyltoluene, n-hexenylbenzene, sec-pentenylbenzene, 3-methylpentenylbenzene and the like in high yield.

Further, as another reaction example to which the catalyst of the present invention can be applied, in the case of a dimerization reaction of α-olefin, a lower α such as ethylene, propylene, 1-butene, isobutylene, 1-pentene is used.
The reaction can be carried out with olefins. For example, production of 4-methyl-1-pentene by dimerization of propylene, production of 4-methyl-1-pentene by co-dimerization of 1-butene and ethylene, 2-methyl-1-pentene by co-merization of isobutylene ethylene. The catalyst of the present invention can be used for the production of In particular, the catalyst of the present invention can be preferably used for the production of 3-methyl-1-pentene by the dimerization of propylene. The dimerization reaction can be usually performed at a reaction temperature of 0 to 300 ° C. and a reaction pressure of 1 to 200 kg / cm ² -G.

〔The invention's effect〕

According to the method of the present invention, a catalyst in which an alkali metal is supported on a powder of an anhydrous potassium compound can be obtained by a method simpler than the conventional method.

〔Example〕

Hereinafter, the method of the present invention will be specifically described with reference to Examples.

Example 1 A granular powder obtained by mist-drying a slurry of potassium carbonate 1.5 hydrate at 150 ° C was calcined at 400 ° C for 2 hours, and then the bulk density and the particle size distribution were measured by the Rotap method under a dry nitrogen atmosphere. It was measured at. The bulk density of this potassium carbonate is 0.67 g / ml, the average particle diameter (median diameter Dmed) is 420 μ,
Further, particles having a particle size of 100 to 800 μ accounted for 92% of the whole.
58 g of this potassium carbonate powder and 2 g of sodium metal were placed in an autoclave (1) together with 200 ml of toluene, and the catalyst of the present invention was prepared by stirring at 190 ° C. for 2 hours at a rotation speed of 600 rpm. When the alkali metal of this catalyst was analyzed by atomic absorption spectrometry, the atomic ratio of metal K to metal Na was 107: 1. After the temperature was lowered to 150 ° C., 400 ml of toluene was added, propylene was injected under pressure, and the initial reaction pressure was set to 60 kg / cm ² . A reaction started at the same time as the introduction of propylene, and a pressure drop was observed.
At the time when the pressure in the container reached 30 kg / cm ² , propylene was injected again to return the pressure to 50 kg / cm ² , and the reaction was restarted. After repeating this operation three times, the reaction was terminated, and the contents were analyzed by gas chromatography (column PEG 6000, 4 m).
The total reaction time was 4 hours. The results are shown in Table 1.

Example 2 80 g of powder obtained by calcining commercially available potassium phosphate at 400 ° C. for 3 hours was placed in an autoclave containing 100 ml of n-decane, and a rotation speed of 800 rpm was applied together with 2 g of metallic sodium pieces.
With stirring, the temperature was raised to 230 ° C. and kept for 3 hours. The pressure at this time was 7 kg / cm ² . According to this method, a catalyst in which metallic sodium was supported on a potassium phosphate powder could be obtained. The catalyst obtained by this method was subjected to a co-dimerization reaction with ethylene. That is, after setting the reaction temperature at 150 ° C., 14 g of ethylene and 21 g of propylene were injected under pressure, and the reaction was carried out for 3 hours while stirring at a rotation speed of 400 rpm. As a result of analyzing the reaction product by gas chromatography, the reaction rate was 55 mol%, and as a product, 1-pentene was 87%, 2-pentene was 5%, 4-methyl-1-pentene was 4% and 3%. -Ethyl-1-pentene was obtained with a selectivity of 2%.

Example 3 3 g of metallic sodium and 70 g of anhydrous potassium sulfate dried by calcining at 400 ° C. were sealed in an autoclave containing 200 ml of cyclohexane, and the catalyst was vigorously stirred at 210 ° C. for 3 hours to catalyst. Prepared. The temperature in the container
After the temperature was set to 110 ° C., 200 ml of dried toluene was added, and 30 g of butadiene was further pressed. Initial pressure was 7 kg / cm ² 5
After reacting for a time, the product was analyzed by gas chromatography. 72% of butadiene was reacted and 5-phenylpentene-2 was produced with a selectivity of 88%. The remaining 12% was a low polymer.

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Claims (1)

[Claims] 1. A powder of an alkali metal and an anhydrous potassium compound is mixed at a temperature not lower than the melting point of the alkali metal in a liquid hydrocarbon catalyst inert to the alkali metal. A method for preparing a catalyst in which powder is loaded with an alkali metal.