JPS5995227A - Preparation of unsaturated alcohol - Google Patents

Abstract

PURPOSE:To improve the yield of the titled compound, without causing the problems such as environmental pollution, lowering of catalytic activity, etc., in the preparation of the titled compound by the hydrogenation of an unsaturated aldehyde, unsaturated fatty acid, etc., by using a composite catalyst having a specific composition and obtained from iron sulfate. CONSTITUTION:The objective compound can be prepared by hydrogenating an unsaturated aldehyde, unsaturated fatty acid or its ester in the presence of a composite catayst containing iron oxide and zinc oxide at an atomic ratio (Fe: Zn) of 9:1-8:2 and obtained from iron sulfate. The catalyst can be prepared, e.g. by adding a precipitant to a mixed aqueous solution of iron sulfate and a zinc salt, and drying and calcining the resultant coprecipitate. The pH of the system in the coprecipitation process is adjusted to 7.0-11.0, preferably 8.0- 9.0. the temperature for the pyrolysis of the precipitate to oxides is 300-800 deg.C, preferably 350-500 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing unsaturated alcohols. More specifically, the present invention relates to a method for producing an unsaturated alcohol using a solid catalyst whose main raw material is iron oxide, which is industrially inexpensive.

Conventionally, various methods for producing unsaturated alcohols have been proposed. Japanese Patent Publication No. 45-2562 proposes a fixed bed reaction method using a zinc-chromium catalyst or a zinc-aluminum catalyst.

Further, Japanese Patent Publication No. 51-36731 proposes a fixed bed reaction system using a four- or five-component catalyst consisting of zinc oxide and/or cadmium oxide, aluminum oxide, chromium oxide and notrium oxide.

However, in the fixed bed reaction method, great care must be taken in refining the raw material fats and oils in terms of catalyst life, and it is difficult to say that it is an efficient manufacturing method when the production volume is small, so unsaturated This is not always a satisfactory method for producing alcohol.

On the other hand, many proposals have been made regarding methods for producing unsaturated alcohols using a suspended bed reaction method. However, most of these proposals have not achieved industrially satisfactory performance in terms of activity and selectivity. However, even those that are satisfactory in terms of performance use highly toxic metals such as cadmium or chromium, which are not desirable from the standpoint of pollution control.

Therefore, the present inventors have achieved excellent selectivity and economy,
Furthermore, as a result of intensive research to find a method for producing unsaturated alcohol that does not cause pollution problems, the present invention was completed. That is,
The present invention provides a method for producing an unsaturated alcohol in which an unsaturated aldehyde, an unsaturated fatty acid, or an ester thereof is hydrogenated using a composite oxide consisting of iron oxide and zinc oxide as a catalyst.
The present invention provides a method for producing an unsaturated alcohol, characterized in that a composite oxide is prepared using iron sulfate as a raw material, and the atomic ratio thereof is Fe:Zn=9:1 to 8:2.

The use of iron and zinc composite oxide catalysts in methods for producing unsaturated alcohols has been known for a long time. For example, in Industrial Chemistry Magazine, Volume 44, Volume 6, Page 74.0 (194, 1), a composite catalyst of iron oxide/zinc oxide = 9575 obtained using ferric nitrate as a raw material was published in Patent No. 15.
No. 1980 describes iron/zinc obtained from iron nitrate.
A composite catalyst of 2/1 to 1/2 has been proposed.

However, although the production method using the above catalyst solves problems such as pollution, it is not necessarily satisfactory in terms of selectivity regarding activity and double bond retention performance.

Therefore, the present inventors have made efforts to improve the above-mentioned iron/zinc composite oxide catalyst, and the present invention has been achieved.

The composite catalyst used in the method of the present invention has a composition of Fe
: It is important that Zn=9:1 to 8:2 and that it is prepared using iron sulfate as a raw material.

When the Fe:Zn ratio is outside this range, activity and selectivity decrease. If a compound other than iron sulfate is used as a raw material, such as a well-known nitrate, the selectivity will be significantly reduced. There are no limitations on zinc salts.

As a catalyst preparation method, any known preparation method can be used as long as the above conditions are satisfied. For example, a method may be mentioned in which a precipitate obtained by a coprecipitation method in which a precipitant is added to a mixed aqueous solution of iron sulfate and zinc salt is dried and calcined.

Precipitants include ammonia, urea, ammonium carbonate,
Aqueous solutions such as thorium carbonate, sodium hydroxide, and potassium hydroxide are used.

p I-I during coprecipitate formation greatly influences catalyst performance. The coprecipitate obtained in the present invention has a pH of 7.0 to 11.
0, preferably between 8o and 90o. In addition, the temperature at which the precipitate is decomposed into oxides has a large effect on catalyst performance.
3oo''C from 8o.

It may be within the range of 350°C, preferably 350°C
Fire in the range of 00'C.

The iron/zinc composite oxide catalyst obtained by the above method is produced under conditions more relaxed than those of known catalysts, that is, the catalyst amount is 1
Even at a reaction temperature of 0% and a reaction temperature of 300'C, unsaturated fatty acids or their esters can be rapidly reduced to the corresponding unsaturated alcohols in high yield and with high selectivity.

The production method of the present invention can be carried out in any of a suspended bed reaction system, a fluidized bed reaction system, or a fixed bed reaction system, in which case the catalyst shape is molded into a shape suitable for each reaction system.

The reaction conditions selected when producing an aliphatic unsaturated alcohol by a suspended bed reaction method are as follows. The amount of catalyst used is preferably from 5% to 30% by weight based on the raw material oil, but if the amount of catalyst is too large, hydrocarbon generation and double bond saturation are likely to occur, resulting in a decrease in selectivity. . Reaction temperature ranges from 250'C to 35
A range of 0°C is preferred, but the higher the reaction temperature, the lower the selectivity. Hydrogen pressure is 150kg/clr to 30
A range of 0 Icy 10 J is preferred.

When charging a catalyst, a catalyst calcined in an oxidizing atmosphere or an inert gas atmosphere can be charged in an oxide state, but it is preferable to use a catalyst that has been appropriately pre-reduced, and more preferably in a raw material oil or fat. A catalyst that has been subjected to a preliminary reduction treatment under the above reaction conditions is charged into the produced alcohol.

The catalyst thus subjected to the reaction can be used repeatedly,
Moreover, no deterioration in catalyst performance was observed.

As described above, since the catalyst used in the present invention has good catalytic performance and a long life, it can be said to be a catalyst suitable for the industrial production of unsaturated alcohols.

Examples are shown below, but the present invention is not limited to these Examples.

Preparation of catalyst (invention product 1) Ferric sulfate (containing 360% Fe2(SO4)) 67.6
g and zinc nitrate 11.0! Add 400 g of water to i' to dissolve the metal salt, and then heat to 90°C. Add 538 g of a 170% aqueous sodium carbonate solution dropwise over 1 hour while stirring and maintaining the temperature at 90"C. After the addition is complete, age at 90°C for 1 hour, separate the precipitate fO, and wash with water from Step 4 (Step 1). do.

After drying the precipitate washed with water at 110°C for a day and night,
Calcinate at 20°C for 2 hours to obtain a catalyst.

The composition of the obtained catalyst was 86% by weight of triiron tetroxide;
14 weight percent zinc oxide.

(Pe:Zn=86.6:13.4 (atomic ratio)) surface, from the X-ray diffraction experiment of the catalyst, the 2θ of the peak corresponding to iron oxide
The value was as shown below, and it was confirmed that it was triiron tetroxide (magnetite).

2θ=355°, 626°, 302°, 569°, 43
1°, 534°.

Preparation of 371° and 185° catalysts (comparative products 1 to 5) Catalysts shown in Table 1 (2) were prepared according to the above method while varying the amounts of ferric sulfate and zinc nitrate.

Table 1, I:) Measurement by atomic absorption spectrometry Example 1 Comparative Examples 1 to 5 Methyl oleate 5oy (saponification value (SV) = 194, iodine value (IV) = 84) and the catalyst prepared by the above method (this Invention product 1, comparative products 1 to 5) 5.09 with rotating stirring type 0
．． 56 autoclave and hydrogen pressure 250 k(j
The reaction was carried out for 15 to 5 hours at a temperature of 300'C and a stirring speed of 700 rpm. The analytical values of the obtained unsaturated alcohol are shown in Table 2.

Table 2 In the method of the present invention using a catalyst having a molar mass of Fe of 866, good results were obtained in terms of both reaction rate and selectivity (retention of double bonds).

Example 2 Using the catalyst of Invention Product 1, hydrogen reduction of methyl oleate was carried out five times under the reaction conditions described in Example 1, using the catalyst repeatedly. The results are shown in Table 3.

Table 3 Preparation of catalyst (invention product 2) Ferric sulfate (containing 360% of Pe2(804)) 63.7
1i' and zinc nitrate 14-91. A catalyst was prepared according to the method described in Example 1 using 550 g of 10% sodium carbonate aqueous solution.

The composition of the obtained catalyst was Fe:Zn=81.8:
It was 18.2.

Example 2 The same operation as in Example 1 was carried out using the catalyst of Invention Product 2. The analytical values of the reaction product were as follows.

OI (V = 185 SV = 10.O After dissolving the salt, 100 cc of 5N ammonia water is added dropwise at room temperature while stirring for 30 minutes.After the dropwise addition is complete, the precipitate is
After washing with water for 1' and 0°C overnight,
Calcinate at 00"C for 1 hour to prepare a catalyst.The composition is Fe
: Zn=86.6 : 13.4.

Comparative Example 6 Hydrogen reduction was performed using the catalyst of Comparative Product 6 under the same conditions as in Example 1. The analytical values of the reaction product are as follows.

0I-IV=185 SV=9.3 IV=76.9 Patent applicant: Kao Soap Co., Ltd.

Claims (1)

[Claims] 1. In a method for producing unsaturated alcohols in which unsaturated aldehydes, unsaturated fatty acids, or their esters are hydrogenated using a composite oxide consisting of iron oxide and zinc oxide as a catalyst, the composite oxide is prepared using iron sulfate as a raw material, and its atoms The ratio is F
A method for producing an unsaturated alcohol, characterized in that e:Zn=9:1 to 8:2.