JPH062702B2 - Method for producing methyl isobutyl ketone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a method for producing methyl isobutyl ketone by a one-step reaction using acetone and hydrogen as raw materials.

Methyl isobutyl ketone (hereinafter referred to as MIBK) is useful as a raw material for organic solvents, paints, stabilizers and the like.

<Prior Art> MIBK is industrially produced from acetone and hydrogen as raw materials by the following three-step method.

The feature of this three-step method is that the steps of condensation, dehydration, and hydrogenation shown in the above formula are sequentially performed. First, using acetone as a base catalyst such as barium hydroxide,
Diacetone alcohol was synthesized by reacting in the liquid phase at atmospheric pressure, and the resulting diacetone alcohol was condensed at 100-120 ℃
The mixture is heated to a dehydration reaction to obtain mesityl oxide.
Subsequently, the mesityl oxide is separated and purified, and then hydrogenated in the presence of a Raney nickel catalyst or the like to produce MIBK.

Although this method is widely used industrially, it has three reaction steps of condensation, dehydration and hydrogenation, and each step requires separation and purification of intermediates such as diacetone alcohol and mesityl oxide. Yes, operation is complicated.
Furthermore, since the condensation reaction of acetone to diacetone alcohol is an equilibrium reaction, there is a problem that the conversion rate is as low as about 15%.

Therefore, studies are being made to produce methyl isobutyl ketone from acetone and hydrogen in one step. This method is advantageous in equilibrium, can increase the raw material conversion rate per one pass, and is economically advantageous as compared with the three-step method.
Conventionally, as a method for manufacturing MIBK by such a one-step method,
Method using an acid type ion exchange resin and palladium-carbon as a catalyst (German Patent No. 1238453), method using a catalyst in which palladium is supported on zirconium phosphate (JP-B-49-6994), H type A method using a catalyst supporting zeolite palladium (Japanese Patent Publication No. 46-2643) has been reported.

However, these conventional methods have the disadvantages that the reaction temperature cannot be raised because a resin is used, the raw material conversion rate is low, the catalyst preparation is complicated, or the MIBK yield is low. The result was not satisfactory.

<Problems to be Solved by the Invention> The present invention has drawbacks in the conventional method for producing MIBK from acetone and hydrogen as raw materials, namely, low raw material conversion rate, low yield of MIBK, and catalyst. The object is to improve the drawbacks such as complicated preparation and to obtain MIBK in a high yield by a simple operation.

<Means for Solving Problems> The present invention relates to a method for producing methyl isobutyl ketone by reacting acetone and hydrogen, and one or two kinds selected from alumina and calcium oxide, magnesium oxide, or strontium oxide. The present invention relates to a method for producing methyl isobutyl ketone, which comprises using a catalyst in which palladium is supported on a carrier composed of the above metal oxide.

Hereinafter, the present invention will be specifically described.

The catalyst used in the method of the present invention is one in which palladium is supported on a carrier composed of alumina and one or more metal oxides selected from calcium oxide, magnesium oxide and strontium oxide. The carrier used in the method of the present invention is usually produced by immersing alumina in an aqueous solution of calcium acetate and then calcining. Gamma-alumina is preferably used as alumina. As an aqueous solution of calcium, magnesium and strontium, an aqueous solution of acetate, nitrate, oxalate of these metals is used, and preferably an aqueous solution of acetate of these metals is used. Firing is usually performed at a temperature of 300 to 600 ° C. When activated below 300 ° C or above 600 ° C, only low activity is obtained.

The amount of palladium supported is usually 0.01 to 5.0% by weight, preferably 0.05 to 1.0% by weight. If it is less than 0.01% by weight, good activity cannot be obtained, and if it is more than 5.0% by weight, the supported palladium cannot be effectively used.

The catalyst used in the method of the present invention is usually produced by immersing alumina in an aqueous solution of calcium acetate or the like, calcining it, and then supporting palladium, but in some cases, after supporting palladium on an alumina carrier, it is treated with calcium acetate or the like. It can also be manufactured by dipping in an aqueous solution and firing.

As the reaction mode of the method of the present invention, the catalyst may be packed in an adiabatic or isothermal reactor and a so-called fixed bed flow reaction in which acetone and hydrogen are passed therethrough, or the catalyst may be suspended in acetone. , Hydrogen may be blown into it to carry out the reaction. When the reaction is carried out by a fixed bed flow reaction, the reaction may be carried out in the gas phase or the liquid phase, but the reaction is preferably carried out in the liquid phase. When the reaction is carried out by the suspension method, the reaction may be carried out batchwise or continuously.

The reaction temperature is usually 80 to 250 ° C, preferably 120 to 250 ° C.
It is carried out at 200 ° C. At temperatures lower than this temperature, the reaction rate becomes slower, and at temperatures higher than this temperature, highly condensation products of acetone increase.

The reaction pressure is usually from atmospheric pressure to 50 atm, and it is preferably from 10 to 30 atm, although it depends on the reaction temperature.

According to the method of the present invention, the preparation of the catalyst is easy, the activity of the catalyst is high, and the selectivity is good. Furthermore, the high stability of the catalyst and its long life make it stable for a long time with a high yield of MIB.
K can be manufactured.

Hereinafter, the method of the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited thereto.

<Example> Example 1. Alumina pellets (KHD-24 manufactured by Sumitomo Aluminum Co., Ltd.) 100 m in 3 mol of 1 mol / l calcium acetate aqueous solution 3
Soak for hours. Then, the pellets were taken out and fired at 400 ° C.

This carrier was immersed in an aqueous solution of palladium chloride, reduced with hydrazine, and calcined at 300 ° C. The amount of palladium carried is 0.1
% By weight.

100 m of this catalyst was filled in a vertically arranged reaction tube with an inner diameter of 28 mm, and acetone was added under the conditions of a temperature of 160 ° C. and a pressure of 20 kg / cm ^2.
158 g / hr (LHSV = 2) and hydrogen at a feed rate of 256 Nm / min were introduced into the reactor to carry out the reaction, and the results shown in Table 1 were obtained. The reaction result was obtained by gas chromatography analysis of the reaction solution.

Examples 2 to 4. Catalysts were prepared using the compounds shown in Table 2 instead of the calcium acetate used in Example 1, and MIBK synthesis reaction was carried out using these catalysts. The catalyst preparation conditions and reaction conditions except that the compounds shown in Table 2 were used in place of calcium acetate
The conditions were the same as described in 1.

Examples 5 to 7. Using the catalyst prepared according to the preparation method described in Example 1, the reaction was carried out under the reaction conditions shown in Table 3, and the results shown in Table 3 were obtained. The reaction was carried out under the same conditions as described in Example 1 except for the reaction conditions shown in Table 3.

Example 8. In an autoclave with an internal volume of 200 m equipped with a magnetic stirrer, 100 m of acetone and the catalyst prepared by the method described in Example 1 were crushed, 2 g of the powdered catalyst was added, and the autoclave was heated to 160 ° C. The pressure inside the autoclave is 20 kg / cm ²
The reaction was carried out while adding hydrogen so as to be stirred.
Hydrogen consumed as the reaction progresses is continuously replenished,
The total pressure was always kept at 20 kg / cm ² . After reacting for 2 hours, the autoclave was cooled, the reaction product was taken out, hydrogen and the catalyst were separated, and then analyzed by gas chromatography to obtain the following results.

Acetone conversion rate ………… 45.7% MIBK selectivity ………… 93.1% IPA selectivity ……… 1.5% DIBK selectivity ……… 2.4% Comparative Example 1. Alumina pellets (KHD-24 made by Sumitomo Aluminum) 100m in palladium chloride Soak in aqueous solution and reduce with hydrazine 30
The catalyst was prepared by firing at 0 ° C. The amount of palladium carried is
It was 0.1% by weight.

MIBK was synthesized using 100 m of this catalyst. The reaction conditions other than the catalyst were the same as those described in Example 1.

Sampling was performed 10 hours after the start of the reaction, and the reaction solution was analyzed by gas chromatography to obtain the following results.

Acetone conversion rate …… 19.8% IPA selectivity …… 9.6% MIBK selectivity …… 86.4% DIBK selectivity …… 3.0% <Effect of the invention> As described above, according to the present invention, alumina and calcium oxide, magnesium oxide, and strontium oxide were selected. Methyl isobutyl ketone is obtained in a high yield in a one-step reaction by reacting acetone and hydrogen in the presence of a catalyst in which palladium is supported on a carrier composed of one or more metal oxides selected from the above. Came to be.

Claims (1)

[Claims] 1. A method for producing methyl isobutyl ketone by reacting acetone with hydrogen, the carrier comprising alumina and one or more metal oxides selected from calcium oxide, magnesium oxide and strontium oxide. A method for producing methyl isobutyl ketone, which comprises using a catalyst having palladium supported on it.