JPH06157396A - Method for producing fatty acid - Google Patents

Abstract

(57) [Summary] [Purpose] Fatty acids can be easily synthesized from aldehydes using a catalyst in the gas phase oxidation method. [Composition] Platinum group element, Cr, M
A fatty acid is produced by contacting a solid catalyst containing at least one selected from the group consisting of n, Fe, Co, Ni, Cu, and Au in the gas phase. According to the present invention, a fatty acid can be synthesized under a reaction condition milder than that of a conventional method, and an operation of separating a product and a catalyst required for a liquid phase oxidation reaction is not required. Further, industrially important acetic acid can be easily synthesized from acetaldehyde.

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 fatty acid, which is a raw material for fibers, pharmaceuticals, resins and the like, from an aldehyde by a gas phase oxidation method using a catalyst in the chemical industry.

[0002]

2. Description of the Related Art The synthesis of fatty acids from aldehydes is an industrially important reaction such as the synthesis of acetic acid from butyraldehyde and the synthesis of benzoic acid from benzaldehyde. In particular,
The synthesis of acetic acid from acetaldehyde is of great industrial importance because acetic acid is a raw material for the production of vinyl acetate, ethyl acetate, etc., and is also used as a raw material for medicines, dyes, and food seasonings.

As a method of synthesizing acetic acid, a method of oxidizing acetaldehyde using manganese acetate as a catalyst in a liquid phase has long been used. After that, a method of oxidizing n-butane or naphtha in a liquid phase with a catalyst such as manganese acetate or a method of synthesizing nickel and cobalt or the like from methanol and carbon monoxide as a catalyst (BASF method) was changed to this.

Further, at present, a method of synthesizing methanol and carbon monoxide in a liquid phase using an Rh complex (Monsan)
to method) has been used. The reason why the method using the Rh complex is the mainstream at present is that the selectivity is high and the reaction conditions are more relaxed than the conventional methods. Further, recently, a method of synthesizing carbon monoxide and hydrogen (synthesis gas), which are inexpensive raw materials, by a gas phase reaction has been studied.

[0005]

However, in the reaction in the liquid phase, there is a problem that it is necessary to separate the product and the catalyst, and in the method using the Rh complex, the iodine compound is selected. Because it improves the
Corrosion measures for the reactor are required, and the reaction conditions are 180-220 ° C.
There is a problem that it is necessary to make the pressure high.

Further, the method of synthesizing carbon monoxide and hydrogen also has the problems that high temperature and high pressure are required, the selectivity is low, and the catalyst life is short.

In view of the above, the present invention has an object to easily synthesize a fatty acid from an aldehyde by a gas phase oxidation method.

[0008]

According to the present invention, an aldehyde and oxygen are added to a platinum group element, Cr, Mn, Fe, Co, Ni, Cu,
A fatty acid is produced by contacting a solid catalyst containing at least one selected from the group consisting of Au in a vapor phase.

[0009]

According to the present invention, the gasified aldehyde and oxygen are converted into platinum group elements, Cr, Mn, Fe, Co, Ni, Cu and A.
A fatty acid is produced by contacting a solid catalyst containing at least one selected from the group consisting of u in the gas phase and oxidizing the aldehyde. Examples of the platinum group element include platinum, palladium, rhodium, iridium, osmium, and ruthenium. These catalysts are used by supporting them on a metal oxide in a reduced or oxidized state with high dispersion. If the reaction temperature is too high, the aldehyde is completely oxidized into carbon dioxide and water, so the reaction is carried out under a fairly mild condition of about room temperature. Further, since the reaction is a heterogeneous system, a complicated reaction device is not required, the reaction can be carried out by a flow method, and it is not necessary to separate the product from the catalyst.

Further, fatty acids can be synthesized with high selectivity by using a catalyst in which platinum is highly dispersed and supported on an inorganic compound such as alumina. In particular,
It is desirable to use metal oxides with a large specific surface area such as alumina and silica. Further, the platinum-supported metal oxide catalyst largely depends on the amount of platinum supported, and by increasing the supported amount, a highly active catalyst can be obtained. Furthermore, the activity also largely depends on the loading method, and by localizing it near the surface of the catalyst layer, the yield of fatty acids can be increased.

[0011]

EXAMPLES Example 1 100 g of γ-alumina, 7 g of chloroplatinic acid as Pt and 200 g of water were added, thoroughly mixed using a ball mill, calcined at 500 ° C. for 1 hour, pulverized and supported on platinum. Alumina was prepared.

Similarly, a palladium catalyst, a rhodium catalyst, and a gold catalyst were prepared by using an aqueous palladium nitrate solution, an aqueous rhodium nitrate solution, and an aqueous chloroauric acid solution in place of chloroplatinic acid so that the loading amount was the same as that of Pt. did.

Further, Cr, Mn, Fe, Co, Ni, Cu,
Each oxide catalyst was prepared by thermally decomposing an aqueous nitric acid solution of Zn, Mg, Ca, and Ba at 500 ° C. in air.

1 g of each of these catalysts was placed in a 150 cm ³ glass container, and acetaldehyde was enclosed so that the acetaldehyde content was 10 vol%. The reaction temperature was constant at 30 ° C. In these, the gas other than acetaldehyde was air. After 3 hours from the introduction of acetaldehyde, acetic acid adsorbed on the glass wall and the catalyst was desorbed under reduced pressure and the yield to acetic acid was determined by GC.

For comparison, γ-alumina not supporting white metal was also reacted. The results are shown in (Table 1).

As shown in Table 1, platinum group, Cr, Mn,
By using Fe, Co, Ni, Cu, Au as a catalyst, acetic acid can be obtained with high selectivity. In particular, by supporting platinum on an alumina catalyst, the most highly active catalyst can be obtained.

Although the batch reactor was used in this example, acetic acid can be continuously synthesized by using the flow reactor if the reaction conditions are appropriately set.

Although the production of acetic acid from acetaldehyde was described in this example, the same catalyst can be applied to the synthesis of fatty acid from other aldehydes.

[0019]

[Table 1]

Example 2 A Pt catalyst was similarly prepared by using silica, titania, cerium oxide, and coconut husk activated carbon powder in place of γ-alumina in Example 1. The activated carbon-supported catalyst was calcined at 300 ° C in a nitrogen stream.

Using these catalysts, acetaldehyde was oxidized in the same manner as in Example 1. The results (Table 2)
Shown in. As shown in (Table 2), it is understood that when platinum is supported on an inorganic compound, it is more effective than when it is supported on an organic compound such as activated carbon. It is speculated that this is because the organic compound such as activated carbon adsorbs the aldehyde on the carrier.

[0022]

[Table 2]

[0023]

INDUSTRIAL APPLICABILITY As described above, according to the method for producing a fatty acid of the present invention, a fatty acid can be easily synthesized from an aldehyde by a gas phase oxidation method.

Front page continuation (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B01J 23/56 301 X 8017-4G 23/72 X 8017-4G 23/74 X 8017-4G C07C 51/235 9356 −4H 53/122 9356-4H 53/124 9356-4H 53/126 9356-4H (72) Inventor Kyoe Yamade 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. An aldehyde and oxygen are added to a platinum group element, C
A method for producing a fatty acid, which comprises contacting a solid catalyst containing at least one selected from the group consisting of r, Mn, Fe, Co, Ni, Cu, and Au in a gas phase to produce a fatty acid. 2. The method for producing a fatty acid according to claim 1, wherein the solid catalyst is an inorganic compound supporting platinum.