JPH05246915A - Method for hydrogenating organic carboxylic acid and/or carboxylic acid ester - Google Patents

Abstract

(57) [Summary] [Objective] In the presence of a highly active supported catalyst having excellent dispersibility, hydrogenation reaction of an organic carboxylic acid and / or a carboxylic ester is efficiently progressed under mild conditions. [Structure] A noble metal of Group VIII of the periodic table, with a BET surface area of 2
A supported catalyst formed by supporting porous carbon of 000 m ² / g or more is used. [Effect] By using high surface area porous carbon as a carrier, the dispersibility and catalytic activity of the obtained supported catalyst can be remarkably enhanced. Therefore, organic carboxylic acid and / or carboxylic acid ester can be used for catalytic hydrogenation reaction. It is possible to obtain corresponding alcohols with high yield and high selectivity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for hydrogenating an organic carboxylic acid and / or a carboxylic acid ester, and particularly to the organic carboxylic acid and / or carboxylic acid ester in the presence of a highly active supported catalyst having excellent dispersibility. The present invention relates to a method for hydrogenating an organic carboxylic acid and / or a carboxylic acid ester, which can efficiently proceed the hydrogenation reaction under mild conditions.

[0002]

2. Description of the Related Art Heretofore, many methods have been known for hydrogenating an organic carboxylic acid and / or a carboxylic acid ester to produce a corresponding alcohol.

For example, as a method for obtaining an alcohol from an organic carboxylic acid, a method in which a carboxylic acid is esterified with a lower alcohol in advance and then catalytically reduced with an Adkins catalyst (copper chromite catalyst) is well known. However, this catalytic reduction is generally carried out under a hydrogen pressure of 200 atm or higher, which is an uneconomical method in terms of energy and equipment. Further, as long as such a Cu-based catalyst is used, there is a problem that the organic carboxylic acid cannot be directly reduced, and the carboxylic acid must be once converted into a carboxylic acid ester for reduction.

On the other hand, a catalyst capable of directly catalytically reducing an organic carboxylic acid is known, and a catalyst in which a noble metal of Group VIII of the periodic table is combined with rhenium, tin or germanium has been proposed. For example, US Pat. No. 4,104,478 describes that the selectivity of alcohol is improved by adding rhenium oxide to a ruthenium-supported activated carbon catalyst. Also, in US Pat. No. 4,659,686,
Using a palladium-rhenium catalyst supported on activated carbon,
A method for producing tetrahydrofuran or γ-butyrolactone from an aqueous maleic acid solution is described. Further, European Patent 282,409 describes a hydrogenation reaction of a higher fatty acid ester using a catalyst in which ruthenium-tin is supported on a porous carrier.

All of these methods have relatively high selectivity for the alcohol or ether produced.

[0006]

However, among the methods using the above-mentioned noble metal-based catalysts, US Pat.
In the method described in Nos. 478 and 4,659,686, 1
A hydrogen pressure of 50 atm or higher is required, and a sufficiently satisfactory reaction activity cannot be obtained. In addition, European Patent 282
The method of No. 409 also does not give sufficiently satisfactory reaction activity.

The present invention solves the above-mentioned conventional problems, and makes the hydrogenation reaction of an organic carboxylic acid and / or carboxylic acid ester proceed efficiently under mild conditions in the presence of a highly active supported catalyst having excellent dispersibility. It is an object of the present invention to provide a method for hydrogenating an organic carboxylic acid and / or a carboxylic acid ester which can be used.

[0008]

A method for hydrogenating an organic carboxylic acid and / or a carboxylic acid ester according to claim 1 is a method of bringing an organic carboxylic acid and / or a carboxylic acid ester into contact with hydrogen in the presence of a catalyst to produce hydrogen. In the method of converting into a catalyst, a supported catalyst comprising one or more noble metals of Group VIII of the periodic table supported on a carrier made of porous carbon having a BET surface area of 2000 m ² / g or more is used. And

The method for hydrogenating an organic carboxylic acid and / or carboxylic acid ester according to claim 2 is characterized in that, in the method according to claim 1, the noble metal of Group VIII is palladium and / or ruthenium.

A method for hydrogenating an organic carboxylic acid and / or a carboxylic acid ester according to claim 3 is the method according to claim 1 or 2, wherein a noble metal of Group VIII of the periodic table is used as a catalyst.
It is characterized by using a supported catalyst in which one or more metal components selected from the group consisting of tin, rhenium and germanium are supported on a carrier.

That is, the inventors of the present invention have conducted extensive studies on a catalyst for reducing a carboxylic acid and / or a carboxylic acid ester, which has a higher activity than conventional noble metal-based catalysts, and as a result, the BET surface area as a carrier is higher than a specific value. The present invention has been completed by finding that the maximum activity is exhibited by using a supported catalyst in which a noble metal is supported on surface area porous carbon.

In the present invention, the organic carboxylic acid is a broadly defined organic carboxylic acid including its acid anhydride. The BET surface area is a known surface area display means, and is a value calculated by measuring the nitrogen adsorption amount and using the BET formula by the mercury porosimetry.

The present invention will be described in detail below.

The noble metal of Group VIII of the Periodic Table, which constitutes the catalyst used in the present invention, includes palladium (Pd), platinum (Pt), rhodium (Rh), ruthenium (Ru) and iridium (Ir). .. These precious metals are 1
The seeds may be used alone or in combination of two or more, and palladium and ruthenium are particularly preferably used.

In the present invention, in addition to the above noble metal, one or more metal components of tin, rhenium and germanium (hereinafter sometimes referred to as "second metal component") are contained in the catalyst. Coexistence is preferable from the viewpoint of improving the selectivity of the product.

On the other hand, as a carrier for supporting these noble metals and further the second metal component, a BET surface area of 2000 m
² / g or more, preferably 2000 to 5000 m ² / g of porous carbon is used.

Such high surface area porous carbon may be obtained from plant raw materials such as coconut main coal, porous carbon obtained from peat or coal, or activated carbon derived from carbonized polymers. It is known that the compound can be produced by treating it with a steam activation method or by treating it with potassium hydroxide at a high temperature (J. Amer. Chem. Soc., 113 ).
1636 ('91)).

The amount of the noble metal supported on the carrier made of such high surface area porous carbon is not particularly limited,
The supported amount is preferably 0.1 to 20% by weight based on the weight of the carrier. Further, when the second metal component is used together with the noble metal, the supported amount thereof is preferably 0.1 to 20% by weight.

In order to produce the supported catalyst of the present invention, for example, the high surface area porous carbon is brought into contact with the raw material compound of the noble metal component and further the second metal component to support it, and then the reduction treatment is carried out. It is sufficient to generate a metal. in this case,
As the compound of the noble metal component and the second metal component used, mineral acid salts such as nitric acid, sulfuric acid and hydrochloric acid are generally used, but organic acid salts such as acetic acid, hydroxides, oxides or complex salts, etc. Can also be used.

The method of contacting the raw material compounds of the noble metal component and the second metal component with the high surface area porous carbon is not particularly limited, but in the usual case, the dipping method can be adopted. That is, for example, a raw material compound is dissolved in a solvent capable of dissolving it, for example, water to form a solution, and high surface area porous carbon is immersed in this solution and impregnated and supported. After the supporting, it is dried and, if necessary, calcined and then reduced. As the reduction process,
Known liquid phase reduction and gas phase reduction are used, and in the case of gas phase reduction, it is usually 100 to 500 ° C., preferably 250 to 35.
Performed at 0 ° C.

The precious metal thus obtained (and the second
The reduction reaction of the organic carboxylic acid and / or carboxylic acid ester of the present invention with hydrogen, which uses a catalyst composed of (metal component) supported high surface area porous carbon, is usually carried out at a temperature of 130 to 35.
0 ° C, preferably 180-300 ° C, hydrogen pressure 10-30
0 kg / cm ² , preferably 50 to 200 kg / cm ²
It is performed in the range of. In this case, either liquid phase suspension reaction or fixed bed reaction can be adopted as the reaction system. Further, the hydrogenation reaction may be carried out without a solvent or, if necessary, a solvent may be used. When a solvent is used, the solvent is not particularly limited as long as it does not adversely affect the reaction, and specifically, water; alcohols such as methanol, ethanol, octanol and dodecanol; tetrahydrofuran, dioxane, tetra Ethers such as ethylene glycol dimethyl ether;
Hydrocarbons such as hexane, cyclohexane and decalin are exemplified.

The amount of the catalyst used in the reaction is preferably 0.1 to 100 parts by weight with respect to 100 parts by weight of the organic carboxylic acid and / or carboxylic acid ester as a raw material.
According to various conditions such as reaction temperature or reaction pressure, it can be arbitrarily selected within a range where a practical reaction rate can be obtained.

The organic carboxylic acid, carboxylic acid anhydride and carboxylic acid ester to be hydrogenated in the present invention may be any one which can be catalytically reduced using the catalyst of the present invention, There is no particular limitation,
For example, acetic acid, caproic acid, caprylic acid, undecenoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, oxalic acid, maleic acid, adipic acid, sebacic acid, cyclohexanecarboxylic acid, benzoic acid, Examples thereof include phthalic acid, esters thereof, phthalic anhydride, maleic anhydride and the like. The alcohol portion constituting the carboxylic acid ester is not particularly limited, but a lower alcohol such as methanol or ethanol is preferable.

In the present invention, in particular, an aliphatic monocarboxylic acid having 1 to 15 carbon atoms and its ester, or 4 carbon atoms.
The dicarboxylic acids of to 6 and their esters, or their acid anhydrides are preferably used. When a C4 dicarboxylic acid is subjected to a hydrogenation reaction according to the present invention, a lactone, a cyclic ether or the like is obtained as a hydrogenation product in addition to the corresponding diol.

[0025]

[Function] BE of porous carbon which has been conventionally provided
The T surface area is 1500 m ² / g or less (carbon 67
148 ('71)). On the other hand, in the present invention, the catalyst carrier has a BET surface area of 2000 m ² / g.
The above-mentioned high surface area porous carbon is used. By using such a high surface area porous carbon, the dispersibility and catalytic activity of the obtained supported catalyst are remarkably enhanced, and thus the yield and selectivity of the catalytic hydrogenation reaction are significantly improved.

[0026]

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist. In the following, "%" means "% by weight".

Example 1 Ruthenium (III) chloride and tin (II) chloride were dissolved in water,
Activated carbon having a BET surface area of 2025 m ² / g was added as a carrier, water was removed by a rotary vacuum dryer, and then under a nitrogen atmosphere,
Bake at 150 ° C for 2 hours, then under a hydrogen atmosphere at 300
Reduction was carried out at 0 ° C. for 2 hours to obtain a 5% Ru-5% Sn / activated carbon catalyst.

0.5 g of maleic anhydride was dissolved in 9.5 g of water and 70 m together with 0.2 g of the catalyst prepared by the above method.
l Spinner stirred autoclave, 10 at room temperature
Hydrogen of 0 kg / cm ² was injected under pressure, and the reaction was carried out at 200 ° C. for 2 hours. The reaction results are shown in Table 1.

Example 2 In Example 1, the carrier has a BET surface area of 3500.
A catalyst was prepared in the same manner except that m ² / g of activated carbon was used, and the hydrogenation reaction was carried out in the same manner. The results are shown in Table 1.

The porous carbon having a BET surface area of 2000 m ² / g or more used in Examples 1 and ² was obtained by mixing coconut shell char with an excess of potassium hydroxide and firing the mixture at about 800 ° C. It is a thing.

Comparative Example 1 In Example 1, the carrier has a BET surface area of 1140.
A catalyst was prepared in the same manner as above, except that m ² / g of activated carbon was used, and the hydrogenation reaction was carried out in the same manner. The results are shown in Table 1.

[0032]

[Table 1]

Example 3 0.15 g of the same catalyst as used in Example 2 was charged into a 70 ml spinner stirring autoclave together with 1.5 g of methyl laurate, and 100 kg / cm ² of hydrogen was introduced under pressure at room temperature at 230 ° C. The reaction was carried out for 2 hours, and the results are shown in Table 2.

Comparative Example 2 A hydrogenation reaction was carried out in the same manner as in Example 3 except that 0.15 g of the same catalyst as used in Comparative Example 1 was used, and the results are shown in Table 2.

[0035]

[Table 2]

[0036]

As described in detail above, according to the method for hydrogenating an organic carboxylic acid and / or a carboxylic acid ester of the present invention, it is possible to enhance the organic carboxylic acid and / or carboxylic acid ester by catalytic hydrogenation reaction. It is possible to obtain corresponding alcohols in high yield and with high selectivity.

According to the method of claim 2, the reaction efficiency is further enhanced. According to the method of claim 3, the selectivity of the product is further improved.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location C07D 307/08 307/33 // C07B 61/00 300

Claims (3)

[Claims] 1. A method of hydrogenating an organic carboxylic acid and / or a carboxylic acid ester by contacting with hydrogen in the presence of a catalyst, wherein one or more noble metals of Group VIII of the periodic table are used as the catalyst. A method for hydrogenating an organic carboxylic acid and / or a carboxylic acid ester, which comprises using a supported catalyst supported on a carrier made of porous carbon having a BET surface area of 2000 m ² / g or more. 2. The method for hydrogenating an organic carboxylic acid and / or a carboxylic acid ester according to claim 1, wherein the noble metal of Group VIII is palladium and / or ruthenium. 3. A supported catalyst comprising a noble metal of Group VIII of the periodic table and one or more metal components selected from the group consisting of tin, rhenium and germanium, as a catalyst. The method for hydrogenating an organic carboxylic acid and / or a carboxylic acid ester according to claim 1 or 2.