JPH0840944A - Production of inner olefin - Google Patents

Abstract

PURPOSE:To enable the production of an inner olefin by isomerization of a terminal olefin in high yield. CONSTITUTION:A terminal olefin is isomerized into inner olefins by using a catalyst prepared by subjecting hydrated alumina and metallic sodium to thermal dispersion in which (a) the water content in the alumina is controlled to 0.5-2.5wt.% and (b) the metallic sodium is used in an amount of more than twice equivalent of the moisture in the alumina.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing internal olefins. More specifically, it relates to a method of producing an internal olefin in a high yield by isomerizing a terminal olefin in the presence of a specific catalyst having excellent activity.

[0002]

2. Description of the Related Art Various methods are known for producing internal olefins by isomerizing terminal olefins. In general, the base catalyst has a high selectivity for the isomerization reaction. Above all, as a solid catalyst that is easy to handle,
It is known that an alkali metal is dispersed and carried on a carrier having a large surface area. For example, J. Am. Chem. Soc., 82 , 38
7 (1960) discloses a catalyst in which sodium metal is supported on dry alumina. However, this catalyst has a drawback that a large amount of catalyst is required due to its low activity.

Further, Japanese Patent Publication No. 55-29055 and Japanese Patent Publication No.
57-21378 discloses a catalyst comprising hydrous alumina and sodium metal in an amount of 1.01 to 2 times equivalent to the amount of water. However, this catalyst also has the drawback of low activity and requiring a large amount of catalyst.

JP-A-62-129145, JP-A-63-19652
Japanese Unexamined Patent Publication (Kokai) No. 7 discloses a catalyst prepared by limiting the loading degree of sodium metal on the catalyst having the same composition as in Japanese Examined Patent Publication No. 55-29055. Although it is possible to use a small amount of the catalyst, there is a drawback that a long reaction time is required because the activity is not sufficiently high.

US Pat. No. 396,309 discloses a catalyst composed of potassium and alumina. However, the use of expensive potassium, which has relatively good activity selectivity, poses a large economic problem for industrial use.

[0006]

OBJECT OF THE INVENTION The object of the present invention is to improve the above-mentioned problems of the prior art in the production of internal olefins by isomerizing terminal olefins. An object of the present invention is to provide an improved process for producing an internal olefin which can obtain a high selectivity in a large amount.

[0007]

Means for Solving the Problems The present invention is a method for producing an internal olefin by isomerizing a terminal olefin using a catalyst obtained by heating and dispersing hydrous alumina and sodium metal. 0.5 to 2.5 wt% and (b) relative to the water content in the alumina,
The present invention relates to a method for producing an internal olefin, which comprises using sodium metal in an amount of 2 times equivalent or more.

As the alumina used in the present invention, various forms of alumina can be used. Of these, high surface area γ, χ, and ρ-type alumina are preferable, and γ-alumina is particularly preferable. Water content in hydrous alumina is 0.5 to
It is 2.5 wt%. It is preferably 0.7 to 2.2 wt%. When the water content is out of the above range, the isomerization activity of the catalyst is lowered.

The water content of alumina can be expressed by the amount of heat loss from the initial various forms of alumina to the conversion to α-alumina. Alumina eventually turns into α-alumina as the firing temperature rises, and there is no heating loss of alumina. The temperature at which α-alumina is transferred is 1000 ° C or higher according to the Chemical Handbook (Applied). Alternatively, according to the Catalysis Engineering Course (catalyst manual for each element), it is 1100-1200 ° C.

The amount of sodium metal used is at least twice the equivalent of the amount of water in the alumina. Preferably 2 to
It is 5 times equivalent. If the amount used is less than twice the equivalent amount, the isomerization activity is reduced, and thus a large amount of catalyst is required. If the amount of sodium metal used is too large, there are problems that the catalyst is likely to become a paste and the effect of improving the activity is reduced. You may use together sodium metal and a small amount of potassium metal.

The catalyst can be prepared by catalytically mixing hydrous alumina and sodium metal. As a mixing method, various methods such as stirring and rotation in an inert gas atmosphere can be used. The mixing order is
A predetermined amount of sodium metal can be added all at once to the hydrous alumina, or can be added in portions.

The mixing temperature is not particularly limited, but is preferably not lower than the melting point of sodium metal and not higher than 450 ° C.

The shape of the catalyst is not particularly limited, and it can be used in any shape such as powder, granules, pellets and spheres. Of these, powdery or granular form is preferable.

Various materials can be used as the terminal olefin of the raw material that can be used in the present invention. For example, 1-butene, 1-pentene, 1-hexene, 1-heptene,
1-nonene, 1-decene, 2-methyl-1-butene, 3-methyl-1
-Linear or branched aliphatic hydrocarbon compounds such as butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 2-methyl-1-pentene, 2,3-dimethyl-1-butene Can be mentioned.

Substituted aromatic compounds having an unsaturated hydrocarbon group such as allyl, such as allylbenzene and allyltoluene, may be mentioned.

Cycloaliphatic compounds such as 2-isopropenyl norbornane, 5-isopropenyl-2-norbornene, 5-vinyl-2-norbornene, methylenecyclopentane, methylenecyclohexane and the like can be mentioned.

1,4-pentadiene, 1,5-hexadiene, 2,
Examples include non-conjugated diene compounds such as 5-dimethyl-1,4-hexadiene and 2,5-dimethyl-1,5-hexadiene.

Among the above compounds, 1-hexene, 1-heptene, 4-methyl-1-pentene and 2-methyl-1-pentene are used as raw materials, and each double bond moves to the adjacent carbon position. It can be suitably used for the production of 2-hexene, 2-heptene, 4-methyl-2-pentene and 2-methyl-2-pentene.

Particularly, it can be preferably used for production of 4-methyl-2-pentene by isomerization of 4-methyl-1-pentene or production of 2-hexene by isomerization of 1-hexene.

The method of the present invention can be carried out by a batch method or a continuous method. Either the liquid phase method or the gas phase method may be used, but the liquid phase method is more preferable. If necessary, it may be diluted with an inert medium, for example, a hydrocarbon such as hexane, but usually the reaction proceeds sufficiently even without using a medium. The reaction is carried out in an inert gas atmosphere, but it is preferable to pretreat the raw material with a desiccant in advance.

As for the reaction temperature, since the reaction proceeds sufficiently even at room temperature, there is no need to particularly heat it, but depending on the purpose,
The reaction may be performed by heating to about 120 ° C. Similarly -10
The reaction may be performed by cooling to about ℃. The amount of catalyst used in the reaction is 1/1000 to 5/10 by weight ratio to the raw material.
0 is preferable, and 5/1000 to 3/100 is particularly preferable.

[0022]

INDUSTRIAL APPLICABILITY By the method of the present invention, the terminal olefin can be isomerized to produce the internal olefin in high yield.

[0023]

【Example】

Example 1 25 g of γ-alumina containing 1.56 wt% of water and 1.170 g of sodium metal were placed in a 100 mL flask and mixed with stirring under a nitrogen atmosphere at 150 ° C. for 2 hours to prepare a catalyst. 50 mL of 0.30 g of this catalyst and 12.90 g of 4-methyl-1-pentene
The mixture was placed in a flask and stirred at room temperature under a nitrogen atmosphere. 0.5
After the lapse of time, the reaction solution was sampled and analyzed by gas chromatography.The conversion rate of 4-methyl-1-pentene was 92.
The yield of 7% and 4-methyl-2-pentene was 91.5%. After that, sampling was performed at 1.0 hours, 2.0 hours, and 3.0 hours, and gas chromatographic analysis was performed. The catalyst preparation and reaction conditions are shown in Table 1, and the results are shown in Table 2.

Examples 2 and 3 Catalyst preparation and reaction were performed in the same manner as in Example 1 except that the mixing temperature of sodium metal with γ-alumina was changed. The catalyst preparation and reaction conditions are shown in Table 1, and the results are shown in Table 2.

Examples 4 and 5 Catalyst preparation and reaction were carried out in the same manner as in Example 1 except that the amount of sodium metal used and the mixing temperature of γ-alumina and sodium metal were changed. The catalyst preparation and reaction conditions are shown in Table 1, and the results are shown in Table 2.

Examples 6 and 7 Catalyst preparation and reaction were carried out in the same manner as in Example 2 except that the water content of γ-alumina and the amount of sodium metal used were changed. The catalyst preparation and reaction conditions are shown in Table 1, and the results are shown in Table 2.

Example 8 A catalyst was prepared and reacted in the same manner as in Example 2 except that the amount of catalyst used in the reaction was 0.15 g. The catalyst preparation and reaction conditions are shown in Table 1, and the results are shown in Table 2.

Example 9 A catalyst was prepared and reacted in the same manner as in Example 2 except that olefin was replaced by hexene-1. The catalyst preparation and reaction conditions are shown in Table 1, and the results are shown in Table 2.

Comparative Example 1 Catalyst preparation and reaction were carried out in the same manner as in Example 3 except that the amount of sodium metal used was reduced. The catalyst preparation and reaction conditions are shown in Table 1, and the results are shown in Table 2.

Comparative Example 2 A catalyst was prepared and reacted in the same manner as in Example 7 except that the amount of sodium metal used was reduced. The catalyst preparation and reaction conditions are shown in Table 1, and the results are shown in Table 2.

Comparative Example 3 A catalyst was prepared and reacted in the same manner as in Example 2 except that γ-alumina having a high water content was used. The catalyst preparation and reaction conditions are shown in Table 1, and the results are shown in Table 2.

Comparative Example 4 A catalyst was prepared by using γ-alumina having a high water content and reducing the amount of sodium metal used.
Catalyst preparation and reaction were carried out in the same manner as in Example 2 except that the amount was 2.00 g. The catalyst preparation and reaction conditions are shown in Table 1, and the results are shown in Table 2.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

[0036]

[Table 4]

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Claims (1)

[Claims] 1. In a method for producing an internal olefin by isomerizing a terminal olefin using a catalyst obtained by heat-dispersing hydrous alumina and sodium metal, (a) the water content in alumina is 0.5 to 2.5 wt%. And (b) a method for producing an internal olefin, which comprises using sodium metal in an amount of at least twice the amount of water in the alumina.