JPH06157376A - Production of higher secondary alcohol - Google Patents

Abstract

PURPOSE:To separate and reuse an aq. soln. of catalyst and obtain the subject compound in a high yield by allowing acetic acid to coexist in a reaction system containing a heteropolyacid and a >=8C higher alpha-olefin. CONSTITUTION:The compound is obtained by hydrating (A) a >=8C higher alpha-olefin (e.g. 1-octene and 1-decene) in the presence of (B) acetic acid in a synthetic system containing an aq. soln. of heteropolyacid (e.g. silicotungstic acid) preferably at 100-180 deg.C for 1-6hr. Further, acetic acid and alpha-olefin are mixed preferably at a B/A molar ratio of 1-30 and a water/alpha-olefin molar ratio in hydration reaction is preferably of 1-15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a higher secondary alcohol useful as a detergent raw material, and more particularly to a method for producing a higher secondary alcohol by hydration reaction of a higher α-olefin.

[0002]

2. Description of the Related Art There are many reports on a two-stage hydration method in which an α-olefin is reacted with sulfuric acid to form a sulfuric acid ester, and the sulfuric acid ester is hydrolyzed to an alcohol. However, this two-stage hydration method has the drawback that the device is corroded by sulfuric acid and the product alcohol is colored. Therefore, a method for producing a secondary alcohol by directly hydrating an α-olefin without using sulfuric acid has also been developed.

For example, JP-B-49-36203 discloses that a lower α-olefin such as propylene or butene is directly hydrated by using a heteropolyacid as a catalyst to obtain a lower 2 such as isopropanol, sec-butanol or tert-butanol. Methods for synthesizing secondary and tertiary alcohols are disclosed. In Japanese Patent Publication No. 58-39134, tert-butanol is produced by selectively hydrating isobutylene from an olefin mixture containing n-butene and isobutylene using an aqueous solution containing 10% by weight or more of heteropolyacid. A method is disclosed.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
It only discloses an example of producing a lower secondary alcohol by direct hydration of a lower α-olefin, and does not mention obtaining a higher secondary alcohol from a higher α-olefin having 8 or more carbon atoms. The reason is that (i) in the case of directly hydrating a higher α-olefin to obtain a higher secondary alcohol, the higher α-olefin is hardly soluble or insoluble in the aqueous solution of heteropolyacid, so that the reaction system is heterogeneous. System, and (ii) thermodynamic chemical equilibrium constant K of direct hydration reaction
It is presumed that the hydration reaction hardly progresses and the yield of the higher secondary alcohol as the target product is extremely low because the value of is extremely small.

In order to improve the solubility of the higher α-olefin in the aqueous solution of the heteropolyacid, a solubilizing agent may be allowed to coexist. However, when the solubilizing agent is used, the organic product and the heteropolyimide after the reaction are completed. Acid aqueous solution (catalyst aqueous solution)
However, there is a problem that the phase separation with the above becomes difficult, the heteropolyacid aqueous solution cannot be separated and reused, and a new heteropolyacid aqueous solution must be used for each reaction.

Therefore, an object of the present invention is to obtain a higher secondary alcohol in a high yield by a hydration reaction of a higher α-olefin, and to separate and reuse an aqueous catalyst solution used in the reaction, thereby using a catalyst. It is intended to provide a novel method for producing a higher secondary alcohol, which can reduce the amount.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, in the presence of heteropolyacid,
In producing a higher secondary alcohol by hydrating a higher α-olefin having 8 or more carbon atoms, it is possible to obtain a higher secondary alcohol in a high yield by allowing acetic acid to coexist in the reaction system, and a heteropoly acid. It was found that the aqueous solution can be separated and reused, and the amount of the catalyst used can be remarkably reduced, and the present invention has been completed.

That is, the present invention is characterized in that acetic acid is allowed to coexist in the reaction system in producing a higher secondary alcohol by hydrating a higher α-olefin having 8 or more carbon atoms in the presence of a heteropolyacid. The gist is a method for producing a secondary alcohol.

The present invention will be described in detail below. In the present invention, the higher α-olefin used as a raw material has 8 carbon atoms.
The above is mentioned, for example, 1-octene (C ₈ ), 1-
Decene (C _10), 1- dodecene (C _12), 1- tetradecene (C _14), 1- hexadecene (C _16), 1- octadecene (C _18), and the like.

In the present invention, the heteropolyacid used as a catalyst contains tungsten (W), molybdenum (Mo) or vanadium (V) as a condensation coordination element. For example, silicotungstic acid (SiO ₂ .1)
2wo _3), phosphotungstic acid (P ₂ O ₅ · 24WO
₃ ), phosphomolybdic acid (P ₂ O ₅ .24MoO ₃ ) and the like. These heteropolyacids are hydrated in water (nH
_It may or may not have ₂ O).

In the hydration reaction of higher α-olefins,
Heteropoly acid as a catalyst is used in the form of an aqueous solution,
Even when the above-mentioned higher α-olefin is added to the aqueous solution of the heteropolyacid, the former is hardly soluble or insoluble in the latter as described above, so that the reaction system becomes heterogeneous and the hydration reaction of the higher α-olefin is extremely high. It proceeds slowly and the target higher secondary alcohol can be obtained only in a low yield.

Therefore, as a result of repeated studies to solve this problem, the present inventor found that when acetic acid was allowed to coexist in a reaction system containing a higher α-olefin and a heteropolyacid aqueous solution, the α-olefin and the heteropolyacid aqueous solution in the reaction system. And the hydration reaction proceeds smoothly to obtain a higher secondary alcohol in a high yield, and the phase separation of the organic product and the heteropolyacid aqueous solution after the reaction is easy. It was confirmed that the heteropolyacid aqueous solution can be separated and reused, and the amount of catalyst used can be significantly reduced. Therefore, the present invention requires that acetic acid coexists in a reaction system containing a higher α-olefin and an aqueous solution of a heteropolyacid. The amount of acetic acid to coexist is such that A / O (mol / mol) is 0.1 to 10 when acetic acid is expressed as A and α-olefin is expressed as O.
An amount of 0 is preferable. The reason is that if the A / O is less than 0.1, the dispersibility between the higher α-olefin and the aqueous solution of the heteropolyacid may be deteriorated, while the A / O is 100.
If it exceeds, the phase separation between the organic product after the reaction and the heteropolyacid aqueous solution may be difficult. Particularly preferred A / O is 1-30.

As will be apparent from the comparative examples described below, even if formic acid and propionic acid, which are closely related compounds to acetic acid, are allowed to coexist in the reaction system, the high yield achieved simultaneously when acetic acid is used. It is impossible to simultaneously achieve the production of higher secondary alcohol and the separation and reuse of the catalyst aqueous solution. This shows a remarkable effect of acetic acid located between formic acid and propionic acid in classifying compounds.

In the hydration reaction, the ratio (W / O) of water (W) to higher α-olefin (O) is 1 to 30.
Is preferred. When W / O is less than 1, the hydration reaction may not proceed, and when W / O exceeds 30, the reaction vessel needs to be large, which is economically unfavorable. Particularly preferable W / O is 1 to 15.

The lower the reaction temperature, the more advantageous it is from the viewpoint of reaction equilibrium. However, in consideration of the reaction rate, it is usually room temperature (25 ° C.) to 200 ° C., particularly preferably 100 to 180 ° C. The reaction pressure may be any pressure that allows the reaction system to maintain the liquid phase without vaporization of the reaction liquid. In order to keep the reaction system in the liquid phase, pressurization with an inert gas may be appropriately performed. The reaction time is not particularly limited, but is usually 0 to 24 hours, and practically about 1 to 6 hours is preferable. The reaction system is not particularly limited, and the reaction can be performed in a batch system, a semi-batch system, a continuous system or the like.

[0016]

The present invention will be further described with reference to the following examples.

Example 1 In a 50 cc glass autoclave, 7.0 g of 1-decene (higher α-olefin), 6.3 g of phosphotungstic acid (heteropolyacid as a catalyst), 2.7 g of water, and 9.9 g of acetic acid. The mixture was mixed so as to be 0 g. The molar ratio (W / O) of water (W) to the higher α-olefin (O) was 3, and the molar ratio of acetic acid (A) to the higher α-olefin (O) (A / O) was also 3. . The obtained mixture is kept at 150 ° C. and pressure of 3.3 kg / cm ² G for 1 hour.
The reaction was carried out by stirring at 500 rpm. After the reaction was completed, the organic product and the phosphotungstic acid aqueous solution were clearly phase-separated, and the phosphotungstic acid aqueous solution could be separated and reused. The obtained organic product phase was analyzed by gas chromatography, and as a result, as shown in Table 1, the yield of secondary alcohol was 0.32 g and the yield of secondary alcohol was 4.0 mo.
%, and the amount of secondary alcohol produced per 1 g of the catalyst used was 0.0508 g.

Comparative Example 1 A hydration reaction of 1-decene was tried under the same conditions as in Example 1 except that acetic acid was not used.
Almost no grade alcohol was produced.

Comparative Example 2 Hydration reaction of 1-decene under the same conditions as in Example 1 except that acetic acid was not used and the amount of the catalyst used in Example 1 was only 6.3 g, which was 42.0 g. Was done. As a result, as shown in Table 1, the secondary alcohol yield similar to that in Example 1 could be finally obtained by making the amount of the catalyst about 7 times the amount of the catalyst in Example 1.

[0020]

[Table 1]

From Table 1, 2 by the hydration reaction of 1-decene
In the production of the primary alcohol, it was revealed that by allowing acetic acid to coexist in the reaction system, the secondary alcohol can be obtained in a high yield with a small amount of the catalyst, and the catalyst aqueous solution after the reaction can be separated and reused. On the other hand, when acetic acid does not coexist in the reaction system, when the same catalytic amount as in the case of acetic acid coexisting, the reaction hardly proceeds, and the catalytic amount of approximately 7% in the case of acetic acid coexisting. It was clarified that the same result as when coexisting acetic acid was obtained for the first time by using a double amount of the catalyst.

Examples 2 to 7 Using acetic acid as a dispersant, various conditions were changed as shown in Table 2, and an experiment for producing a higher alcohol by a hydration reaction of 1-decene was conducted. The results are shown in Tables 2 and 3.

[0023]

[Table 2]

[0024]

[Table 3]

As is clear from Tables 2 and 3, secondary alcohols were obtained in high yield also in Examples 2 to 7,
It was also confirmed that the aqueous catalyst solution could be separated and reused.

Examples 8-10 1-octene as the higher α-olefin (Example 8),
Hydration reaction of a higher α-olefin was carried out in the same manner as in Example 1 except that 1-dodecene (Example 9) and 1-tetradecene (Example 10) were used and various reaction conditions were changed as shown in Table 1. High-grade secondary alcohol was obtained. The results are shown in Table 4.
Shown in.

[0027]

[Table 4]

As is clear from Table 4, the secondary alcohol was obtained in high yield and the catalyst aqueous solution was also separated when 1-octene, 1-dodecene and 1-tetradecene were used as the higher α-olefin. It was confirmed that it could be reused.

Example 11 and Comparative Examples 3 to 4 Acetic acid and its related compounds, formic acid and propionic acid, were added as carboxylic acid species to hydrate 1-decene. As a result, as shown in Table 5, in Example 11 using acetic acid, the dispersibility of 1-decene and the catalyst aqueous solution was good during the reaction, and the secondary alcohol could be obtained in a high yield and after the reaction. It was revealed that the catalyst aqueous solution of 1 was also very easily separated from the organic product, and the separated catalyst aqueous solution could be reused. On the other hand, in Comparative Example 3 using formic acid, the dispersibility of 1-decene and the aqueous catalyst solution was poor during the reaction, the reaction rate was slow, and the secondary alcohol was obtained only in a low yield. Further, in Comparative Example 4 using propionic acid, the system became uniform during the reaction,
Although the secondary alcohol could be obtained in high yield, the aqueous catalyst solution could not be separated from the organic product after the reaction,
It became clear that they were not industrially compatible.

[0030]

[Table 5]

Example 12 According to the method of the present invention, the catalyst aqueous solution separated after the reaction was separated, and in order to confirm that it could be repeatedly used, four repeated experiments were carried out as shown below. That is, first, under the conditions shown in Table 6, the first reaction (Run No.
1) was performed. The results of the first reaction are shown in Table 6.

After the first reaction, the second reaction (Run No. 2) was performed under the conditions shown in Table 6 using the catalyst aqueous solution separated and recovered and the novel 1-decene. The results of the second reaction are shown in Table 6. After the second reaction, a third reaction (Run No. 3) was performed under the conditions shown in Table 6 using the separated and recovered aqueous catalyst solution and novel 1-decene. The results of the third reaction are shown in Table 6. After the third reaction, the catalyst aqueous solution separated and recovered and the novel 1-decene were used to perform the fourth reaction under the conditions shown in Table 6.
A round reaction (Run No. 4) was performed. The results of the fourth reaction are shown in Table 6.

[0033]

[Table 6]

As is clear from Table 6, the secondary alcohol yields in the first reaction, the second reaction, the third reaction and the fourth reaction were 5.6%, 5.3% and 5%, respectively. .3
% And 5.2%, and almost no decrease in secondary alcohol yield was observed.

[0035]

According to the present invention, a higher secondary alcohol can be obtained in a high yield by a hydration reaction of a higher α-olefin, and an aqueous catalyst solution used in the reaction can be separated and reused. Provided is a novel method for producing a higher secondary alcohol capable of significantly reducing the amount.

Claims (1)

[Claims] 1. A higher secondary alcohol characterized by allowing acetic acid to coexist in a reaction system when a higher secondary α-olefin having 8 or more carbon atoms is hydrated in the presence of a heteropolyacid to produce a higher secondary alcohol. Manufacturing method.