JPS63196527A - Production of inner olefin - Google Patents

Abstract

PURPOSE:To improve catalytic activity and to obtain the aimed compound with a small amount of catalyst and efficiently in producing a stable inner olefin, by isomerizing an olefin, by using a solid basic catalyst obtained by treating alumina with an alkali metal at a specific temperature. CONSTITUTION:In producing a stable inner olefin by isomerizing the double bond of olefin, hydrous alumina especially hydrous alumina of gamma-, x- rho-type having large surface area is heat-treated with >=equivalent based on water mol amount of the alumina, preferably 1.01-2 equivalents based on the alumina of an alkali metal in an inert gas atmosphere at 180-350 deg.C, preferably 200-300 deg.C to give a solid basic catalyst. The solid basic catalyst is used and the aimed compound is obtained with an extremely smaller amount of catalyst than by a conventional procedure, in a remarkably high efficiency, in high yield, safely, industrially and advantageously without causing by-products such as polymers, etc., and danger such as ignition, etc.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for producing internal olefins, and more particularly to a method for producing more stable internal olefins by isomerizing olefins in the presence of a specific catalyst. It is.

<Prior Art 1: Problems to be Solved by the Invention> Various methods are known for isomerizing olefins into more stable internal olefins. However, generally known methods often have many undesirable elements such as decomposition of olefins, formation of unnecessary olefin polymers, and randomization, and are economically disadvantageous and limited. .

As catalysts for such isomerization reactions, liquid bases such as mixtures of alkali metal hydroxides and aprotic organic solvents, alkali metal amides and amines, or organic alkali metals and aliphatic amines are known. however,
Methods using such liquid base reagents do not have sufficient catalytic activity, require large amounts of expensive reagents, and are difficult to separate and recover from the reaction mass, requiring complicated separation. There is a problem that not only a recovery process is required but also a large amount of energy is consumed.

Also, as solid isomerization catalysts, catalysts in which alkali metals are dispersed in carriers with large surface areas, such as activated carbon, silica gel, alumina, etc., are known (J, Am
, Chew, Soc, 82387 (1960)
).

However, in such solid catalysts, the alkali metal itself is simply finely dispersed on a carrier, and when it comes into contact with air, it ignites and becomes deactivated, so there are major drawbacks in terms of operability and safety. Also, the isomerization ability was unsatisfactory.

The present inventors have already developed a new catalyst using alumina, alkali metal hydroxide, and an alkali metal as raw materials and a new catalyst using hydrous alumina and an alkali metal as raw materials as efficient catalysts that do not have the problems of isomerization catalysts. In addition to discovering new catalysts, we also discovered that these solid base catalysts are safer and are excellent as catalysts for the isomerization of olefins to internal olefins, without the risk of ignition even in the air. (Japanese Patent Publication No. 57-21378, Japanese Patent Publication No. 55-29055, Japanese Patent Publication No. 41562-1982, Japanese Patent Publication No. 55-29056, Japanese Patent Publication No. 55-29058).

The present inventors conducted further studies in order to find a more industrially superior method for producing internal olefins using such solid base catalysts, and as a result, they heated hydrous alumina and an alkali metal, which are raw materials for the catalyst. They discovered that the temperature at which the catalyst is activated is particularly important, and that if the catalyst is prepared at a specific temperature, the catalytic activity can be significantly improved, and isomerization can proceed efficiently with a small amount of catalyst.After further various studies, the present invention was completed. .

In other words, the present invention isomerizes the double bonds of olefins and produces more stable internal olefins by isomerizing the double bonds of olefins. amount of alkali metal in an inert gas atmosphere, 180
The present invention provides an industrially excellent method for producing internal olefins, which is characterized by using a solid base catalyst heated at a temperature of 350' to 350'C.

As the hydrated alumina that is the raw material for the solid base catalyst in the present invention, various forms of hydrated alumina other than α-alumina are used.

Alumina is usually produced by firing aluminum hydroxide, but it is known that alumina exists in various forms, taking various metastable structures and varying amounts of water depending on the firing temperature and time. There is. In the present invention, such alumina is mainly used. In particular, hydrous alumina with a high surface area such as r-type and χ-1ρ-type is preferably used. Also, hydrated bodies of alumina-containing materials,
For example, water-containing substances such as kaolin and alumina silicate can be used, but the alumina mentioned above is particularly preferred, and it is said that as the firing temperature increases, alumina will eventually convert to α-alumina, and the loss of alumina on heating will disappear. Although it is not so easy to measure the amount of water contained in alumina, it can be expressed as the amount of water lost by heating until the initial various forms of alumina are converted to α-alumina. The water content of the hydrated alumina is usually in the range of 1.3 to 10% by weight, preferably 2 to 7% by weight.

Further, examples of the alkali metal which is the other raw material of the catalyst used in the present invention include sodium, potassium, rubidium, etc. of Group 1 of the periodic table. Two or more of these alkali metals may be used, or an alloy thereof, such as an alloy of sodium and potassium, may be used.

The amount of the alkali metal to be used must be more than an equivalent to the molar amount of water in the hydrated alumina, and preferably 1. It is 1 to 2 times equivalent.

When making the alkali metal act on the hydrated alumina, a predetermined amount of the alkali metal may be added at once, or an amount equivalent to the water content of the hydrated alumina may be added to cause a sufficient reaction, and then the remaining alkali metal may be added. In the latter case, the alkali metal added first and the alkali metal added later may be different.

The catalyst used in the present invention is prepared by making the above-mentioned hydrated alumina and alkali metal interact with each other at a specific temperature in an inert gas atmosphere. , argon, etc.

For the catalyst used in the present invention, the preparation temperature, that is, the temperature at which hydrated alumina and alkali metal are allowed to interact with each other, is extremely important.The catalyst preparation temperature is 180 to 350"C, which has a significant effect on the catalytic activity. Preferably, the temperature is 200 to 330° C. If the catalyst is prepared at such a temperature, a catalyst with extremely high activity never seen before can be obtained, and the desired reaction can be efficiently completed with a small amount of catalyst.

The heating time varies depending on the selected temperature conditions, etc., but is usually 15 minutes.
Minutes to 10 hours is sufficient.

In this way, a catalyst can be obtained which is safer than known solid base catalysts without the risk of ignition, and has significantly higher activity.

The present invention uses such a solid base catalyst to isomerize olefins to more stable internal olefins,
Such raw material olefins include, for example, 1-butene, 1
-Pentene, 1-hexene, ■-hebutene, l-nonene, ■-decene, 2-methyl-1-butene, 3-methyl-
1-butene, 4-methyl-1-pentene, 3-methyl-
Chain compounds such as 1-pentene, 2-methyl-1-pentene, 2,3-dimethyl-1-butene, aromatic compounds such as allylbenzene, allyltoluene, 2-isopropenylnorbornane, 5-isopropenyl- Bridged ring compounds such as 2-norbornene and 6-methyl-5-vinylnorbornene (excluding 5-vinyl-2-norbornene),
Cyclic compounds such as methylenecyclopenkune and methylenecyclohexane, 1,4-pentadiene, 1,5-hexadiene, 2,5-dimethyl-1,4-hexadiene, 2.
Terminal olefin compounds such as non-conjugated olefins such as 5-dimethyl-1,5-hexadiene, 4-methyl-2-pentene, 5-(2-propenyl)-2-norbornene, etc. having a double bond other than the terminal However, examples include compounds that can be isomerized to a more stable position.

In producing internal olefins, the amount of solid base catalyst used is usually 1/3000 to 1150 liters, preferably 1/2000 to 1/2000 liters, of the weight of the raw material.
100 weight. Regarding the temperature of isomerization, there is no need to particularly heat the reaction as the reaction proceeds sufficiently at room temperature, but depending on the purpose it may be heated.
0''C Preferably carried out at a temperature range of -10 to 100°C.

If necessary, the reaction can be carried out by diluting with an inert medium, for example, a hydrocarbon such as pentane, hexane, heptane, dodecane, etc., but no medium is sufficient.The method of the present invention can be carried out by either a batch method or a continuous method. , for isomerization,
It is also effective to pre-treat the raw material with a desiccant such as alumina.

In order to carry out isomerization more safely and reliably, it may be carried out under an inert gas atmosphere.

The isomerization reaction product is analyzed by a known method such as gas chromatography and separated from the catalyst by filtration or the like.

<Effects of the Invention> In this way, an internal olefin isomerized to a more stable position, which is the object of the present invention, can be obtained, but according to the method of the present invention, olefins can be produced extremely efficiently even with a significantly smaller amount of catalyst than in the known method. The isomerization reaction can be completed, and internal olefins can be obtained in high yield without producing by-products such as polymers.

In addition, the reaction can proceed safely without any risk of ignition, so it is extremely useful as an industrial method for producing internal olefins.

<Examples> The present invention will be explained in more detail with reference to the following examples, but the present invention is not limited only to the examples.

Reference Example 1 30.0 g of γ-alumina containing 2.2% by weight of water was placed in a 100 d flask and heated to 300° C. while stirring under nitrogen gas flow. 1.2 g of metallic sodium was introduced, stirred at the same temperature for 1 hour, and then allowed to cool. 30.9 g of a gray-blue catalyst was obtained.

Reference Example 2 30.0 g of γ-alumina containing 2.0% by weight of water was placed in a 100-mm flask and heated to 260° C. while stirring under nitrogen gas flow. 0.75g of metallic sodium
After adding 0.45 g of metallic potassium and stirring for 1 hour, the mixture was allowed to cool. 31.0 g of a gray-blue catalyst was obtained.

Reference Example 3 30.0 g of γ-alumina containing 2.2% by weight of water was placed in a 100 ml flask and heated to 210'C while stirring under nitrogen gas flow. Metallic sodium 1.
2g of the mixture was introduced, stirred at the same temperature for 1 hour, and then allowed to cool. 30.8 g of a gray-blue catalyst was obtained.

Reference example 4 30.0 g of T-alumina containing 2.21 g% water
The mixture was placed in a 100-jd flask and heated to 400° C. with stirring under nitrogen gas flow. Metallic sodium 1.2
After stirring at the same temperature for 1 hour, the mixture was allowed to cool. 30.9 g of a gray-blue catalyst was obtained.

Example 1 0.25 g of the solid base prepared in Reference Example 1 and 4-methyl-1-pentene (&[
l composition: 4-methyl-1-pentene 98.9%, 4-methyl-2-pentene 1.1%) 22.2g was added and 15-20%
After stirring at °C for 16 hours, the reaction solution was analyzed and found that 4-
Methyl-1-pentene 0.4%, 4-methyl-2-pentene 10.8%, 2-methyl-2-pentene 88.8%
Met.

Example 2 0.20 g of the solid base prepared in Reference Example 2 and 4-methyl-1-pentene (&
Formation: Add 28.0g (same as Example 1) and mix at 15-20℃
After stirring for 16 hours, the reaction solution was analyzed and found to be 4.
-Methyl-1-pentene 0/.%, 4-methyl-2-pentene 9.0%, and 2-methyl-2-pentene 90.6%. .

Example 3 10 (0.23 g of the solid base prepared in Reference Example 3 and 20.7 g of 4-methyl-1-pentene (composition: same as Example 1) were added to an LD flask under a nitrogen atmosphere at 15 to 20°C. After stirring for 16 hours, the reaction solution was analyzed and found to be 0.6% of 4-methyl-1-pentene, 37.8% of 4-methyl-2-pentene, and 61.6% of 2-methyl-2-pentene. Ta.

Comparative Example 1 0.25 g of the solid base prepared in Reference Example 4 and 4-methyl-l-pentene (&l
After addition of 22.2 g (same composition as in Example 1) and stirring at 15 to 20°C for 16 hours, analysis of the reaction solution revealed that 1.5% of 4-methyl-1-pentene and 53% of 4-methyl-2-pentene were added. .2% and 2-methyl-2-pentene 45.3%.

Example 4 0.25 g of the solid base prepared in Reference Example 1 and 2,3-dimethyl-1-butene (composition: 2,3-dimethyl-1-butene 99.4%, 2
, 3-dimethyl-2-butene (0.6%)) and stirred at 15 to 20° C. for 24 hours. After the reaction, the catalyst was separated by filtration to obtain 43.3 g of a reaction solution. When this product was analyzed by gas chromatography, 2.
3-dimethyl-1-butene was 8.0% and 2.3-dimethyl-2-butene was 92.0%.

Comparative Example 2 0.24 g of the solid base prepared in Reference Example 4 and 43.2 g of 2,3-dimethyl-1-butene used in Example 4 were added to a 100 jd flask under a nitrogen atmosphere, and the mixture was heated at 15 to 20°C.
After the reaction was stirred for 4 hours, the catalyst was separated by filtration.
41.5 g of reaction solution was obtained. When this product was analyzed by gas chromatography, 2.3-dimethyl-1-butene was 34.8% and 2.3-dimethyl-2-butene was 65%.
It was 2%.

Claims (1)

[Claims] In producing stable internal olefins by isomerizing olefins, hydrated alumina and an alkali metal in an amount exceeding the equivalent amount to the molar amount of water in the alumina are mixed in an inert gas atmosphere at a temperature of 180 to 350°C. A method for producing internal olefins, characterized by using a solid base catalyst subjected to heating action.