JPH05301842A - Production of lower fatty acid ester - Google Patents

Abstract

PURPOSE:To produce a fatty acid ester in excellent productivity (space yield) by reacting a lower fatty acid with a lower olefin. CONSTITUTION:The reaction between a lower fatty acid and a lower olefin is carried out in the presence of phosphotungstomolybdic acid, silicotungstomolybdic acid or at least one salt selected from the group consisting of (1) cesium salt, (2) rubidium salt, (3) thallium salt, (4) ammonium salt and (5) potassium salt of the acids.

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 ester by reacting a lower fatty acid and a lower olefin with extremely high productivity (hereinafter referred to as space-time yield).

[0002]

2. Description of the Related Art Conventionally, a method of reacting a lower fatty acid with a lower olefin to produce a corresponding ester using a strongly acidic cation exchange resin as a catalyst, or as disclosed in JP-B-53-6131. , Mineral acids such as sulfuric acid and phosphoric acid, and heteropolyacids such as phosphotungstic acid and phosphomolybdic acid, as catalysts, or JP-A No.
As disclosed in 7-183743, a method of using aromatic disulfonic acid and / or its ester as a catalyst has been announced.

[0003]

However, in the reaction using the above-mentioned conventional catalyst as compared with the present invention, the space-time yield is low and the catalyst life is short, so that the production method is far from industrialization. The present invention has been made in view of the above circumstances, the space-time yield is significantly higher than that of the conventional method, and
It is an object of the present invention to find a catalyst having a long life and to provide a method for easily producing a lower fatty acid ester.

[0004]

In order to achieve the above object, in the method of the present invention, phosphorus tungstomolybdic acid, silicotungstomolybdic acid, or (1) cesium salt or (2) rubidium salt thereof is used as a catalyst. The lower fatty acid and the lower olefin are reacted in the presence of a catalyst of at least one salt selected from the group consisting of (3) thallium salt, (4) ammonium salt, and (5) potassium salt.

The lower fatty acids used in the method of the present invention include formic acid, acetic acid, propionic acid, valeric acid, acrylic acid, methacrylic acid and crotonic acid, and the lower olefins include ethylene, propylene and butene-. 1,
Butene-2 and isobutylene are listed. When an olefin having 5 or more carbon atoms is used, the production reaction of a fatty acid ester is slow, and if the reaction pressure or reaction temperature is increased to compensate for it, not only the by-products such as a polymer increase but also the catalyst life increases. Noticeably shorter. The reaction mode according to the present invention is a gas phase reaction.

The reaction pressure is in the range of 0 to 50 kg / cm ² G, preferably 0 to 10 kg / cm ² G. The reaction temperature is 50 to 3
The temperature is preferably 00 ° C, particularly 100 to 250 ° C. If the reaction temperature is lower than 50 ° C, the reaction rate becomes slow and the space-time yield remarkably decreases. On the other hand, when the temperature exceeds 300 ° C, the by-products increase and the catalyst life shortens. The molar ratio of the lower olefin to the lower fatty acid of the feedstock is 1 to 30, preferably 3 to 20.

Although alcohol is produced in the presence of water in the reaction, the reason for which the reason is not clear is that adding 1% by volume of water vapor to the raw material gas prolongs the catalyst life. In this reaction, the space velocity (SV) is 100 to 5000 Hr ⁻¹ , especially 300 to 2 under the standard condition of the mixed gas.
It is preferred to pass the catalyst at 000 Hr ^-1 .

The mixed coordination type heteropolyacid catalyst used in the present invention preferably has a large surface area, a high acid strength and a large amount of acid, and may be used by itself or supported on a carrier. The carrier to be used may be a porous material that is generally used as a carrier or a substance that can be granulated into a porous material, and examples thereof include one or more of silica, diatomaceous earth, titania, activated carbon, alumina and silica-alumina. A mixture of is used.

As a supporting method, adhesion (coating)
Means such as a method, an impregnation method, an evaporation-drying method, and a kneading-molding method are applied. Preparation of the catalyst according to the method of the present invention, specifically, for example, commercially available phosphorus tungstomolybdic acid or silicate tungstomolybdic acid, etc. is dissolved in an appropriate amount of water, to which cesium, rubidium, thallium, ammonium, potassium, etc. A solid heteropolyacid salt can be obtained by mixing nitrates, carbonates and the like as powders, or by mixing them in an aqueous solution with an aqueous solution of phosphotungstic acid and the like and evaporating to dryness. When supported on a carrier, the above-mentioned mixed solution (slurry or uniform) is impregnated and supported on the carrier, kneaded with a carrier powder, or a solid heteropolyacid salt is adhered (for example, coated) to the carrier, and any means can be used. Done in. After that, the obtained solid matter is heated at 50 to 350 ° C., preferably 1 at 50 ° C. under an inert gas atmosphere such as air or nitrogen.
It is obtained by heat treatment at 00 to 300 ° C.
If the temperature is less than 50 ° C, the removal of water will be insufficient, and 3
If it exceeds 50 ° C, the catalyst deteriorates.

[0010]

[Equation 1]

[0011]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. Example 1 250 g of phosphorus tungstomolybdic acid (manufactured by Nippon Inorganic Chemical Co., Ltd.) was dissolved in 175 cc of pure water using a 1 liter flask, and 50 g of cesium nitrate (manufactured by Wako Pure Chemical Industries) was added to pure water 3
The solution dissolved at 50 cc was added dropwise over 90 minutes to obtain a yellow precipitate. The water content in the deposited precipitate was evaporated in a hot water bath to form a slurry, and then dried in air at 150 ° C. for 3 hours. The dried product was crushed, a product having a diameter of 1 to 2 mm was separated, and further baked in air at 200 ° C. for 5 hours. 10 g of the calcined product obtained by this operation is used as a catalyst in the reaction.

A gas obtained by mixing acetic acid: ethylene: steam in a volume ratio of 6.8: 92.2: 1 at a reaction temperature of 150 ° C. and a pressure of 5 kg / cm ² G was introduced at a flow rate of 10.7 l / Hr. ,
The reaction was carried out. The reaction product gas was cooled, and the condensed reaction solution was analyzed by gas chromatography to evaluate the activity. As a result, the acetic acid conversion rate was 65.1% and the yield was 64.
7%, and the space-time yield of acetic acid obtained from this result was 1
It became 85.

Example 2 The same conditions as in Example 1 were used except that 26 g of potassium nitrate (manufactured by Wako Pure Chemical Industries) was used instead of cesium nitrate. As a result, the conversion rate of acetic acid was 61.7%, and the yield was 61.5%. The space-time yield of ethyl acetate determined from this result was 17%.
It became 6.

Example 3 Ammonium nitrate (manufactured by Wako Pure Chemical Industries) instead of cesium nitrate
Was the same as in Example 1, except that the amount was 15 g. As a result, the conversion of acetic acid was 68.1% and the yield was 67.4%. The space-time yield of ethyl acetate calculated from this result was 19%.
It became 3.

Example 4 The same conditions as in Example 1 were used except that thallium nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) was 51 g instead of cesium nitrate. As a result, the conversion rate of acetic acid was 45.8% and the yield was 44.7%. The space-time yield of ethyl acetate obtained from this result was 12
It became 8.

Example 5 Rubidium carbonate (manufactured by Wako Pure Chemical Industries) instead of cesium nitrate
Was the same as in Example 1 except that the amount was 22 g. As a result, the conversion rate of acetic acid was 42.0% and the yield was 41.2%. The space-time yield of ethyl acetate obtained from this result was 11%.
It became 8.

Example 6 Using a 1-liter flask, 25 g of phosphorus tungstomolybdic acid (manufactured by Nippon Inorganic Chemical Co., Ltd.) was dissolved in 25 cc of pure water, and 100 cc of a silica carrier was added and impregnated and supported.
The supported carrier was dried and calcined under the same conditions as in Example 1 above and used as a catalyst for reaction under the same conditions as in Example 1. As a result, the conversion rate of acetic acid was 90.0% and the yield was 88.5%, and the space-time yield of ethyl acetate determined from this result was 253.

Example 7 Using the same catalyst (35 g) as in Example 1, a reaction temperature of 180 was used.
At a temperature of 5 ° C. and a pressure of 5 kg / cm ² G, a mixed gas of acrylic acid: ethylene: steam in a volume ratio of 1: 18: 1 was used, and the flow rate was 35.
The reaction was carried out by introducing with 1 / Hr. The reaction product gas was cooled, the condensed reaction liquid was analyzed by gas chromatography, and the activity was evaluated. As a result, the conversion rate of acrylic acid was 64.6%, and the yield was 60.4%. The space-time yield of ethyl acrylate obtained from these results was 135.

Example 8 150 g of phosphorus tungstomolybdic acid (manufactured by Nippon Inorganic Chemical Co., Ltd.) was dissolved in 75 cc of pure water using a 1 l flask.
To this, 22 g of cesium nitrate (manufactured by Wako Pure Chemical Industries) was added to pure water 160
The substance dissolved in cc was added dropwise over 90 minutes to obtain a yellow precipitate. 500 cc of silica having a diameter of 1 to 2 mm was put in this and stirred, and the water content in this was evaporated in a hot water bath until it became a slurry, then dried in air at 150 ° C for 3 hours, and further in air at 200 ° C. It was baked for 5 hours. 35 g of the calcined product obtained by this operation was used as a catalyst in the reaction under the same conditions as in Example 4. As a result, the conversion of acrylic acid was 86.6% and the yield was 81.4%, and the space-time yield of ethyl acrylate obtained from this result was 182.

Example 9 Using 10 g of the same catalyst as in Example 2, a reaction temperature of 150
A gas prepared by mixing acetic acid: propylene: steam at a volume ratio of 6.8: 98.2: 1 at a temperature of 5 kg / cm ² G was introduced at a flow rate of 10.7 l / Hr to carry out a reaction. The reaction product gas was cooled, the condensed reaction liquid was analyzed by gas chromatography, and the activity was evaluated. As a result, the conversion rate of acetic acid was 41.1%, and the yield was 38.6%. The space-time yield of propyl acetate calculated from these results was 128.

Example 10 Using a 1 liter flask, 250 g of calcium tungstomolybdic acid (manufactured by Nippon Inorganic Chemicals Co., Ltd.) was dissolved in 135 cc of pure water, and 37 g of cesium nitrate (manufactured by Wako Pure Chemical Industries) was added to pure water 2
The material dissolved at 60 cc was added dropwise over 90 minutes to obtain a yellow precipitate. The water content in the deposited precipitate was evaporated in a hot water bath to form a slurry, and then dried in air at 150 ° C. for 3 hours. The dried product was crushed, a product having a diameter of 1 to 2 mm was separated, and further baked in air at 200 ° C. for 5 hours. 10 g of the calcined product obtained by this operation was used as a catalyst in the reaction under the same conditions as in Example 1. As a result, the conversion rate of acetic acid was 62.8.
%, The yield was 62.5%, and the space-time yield of ethyl acetate determined from this result was 179.

Comparative Example 1 Commercially available phosphotungstic acid (manufactured by Nippon Inorganic Chemical Co., Ltd.)
After drying at 13 ° C for 13 hours, the mixture was molded into tablets, which were crushed and sieved, and a product having a diameter of 1 to 2 mm was separated, and 10 g of the product was used as the catalyst under the same conditions as in Example 1. ..

Comparative Example 2 The same conditions as in Example 1 were used except that a commercially available phosphomolybdic acid (manufactured by Wako Pure Chemical Industries, Ltd.) was used as a catalyst in the same manner as in Comparative Example 1.

Comparative Example 3 The same conditions as in Example 1 were used except that a commercially available silicotungstic acid (manufactured by Wako Pure Chemical Industries, Ltd.) was used as a catalyst in the same manner as in Comparative Example 1.

Comparative Example 4 The same conditions as in Example 1 were used except that a commercially available silicomolybdic acid (manufactured by Wako Pure Chemical Industries, Ltd.) was used as a catalyst in the same manner as in Comparative Example 1.

Comparative Example 5 The conditions were the same as in Example 6 except that phosphotungstic acid (manufactured by Nippon Inorganic Chemical Co., Ltd.) was used instead of phosphorus tungstomolybdic acid.

Comparative Example 6 The same conditions as in Example 6 were used except that phosphomolybdic acid (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of phosphotungstomolybdic acid.

Comparative Example 7 The conditions were the same as in Example 6 except that silicotungstic acid (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of phosphorus tungstomolybdic acid.

The above-mentioned Examples 1 to 10 and Comparative Examples 1 to 7
Table 1 shows the catalyst product names and amounts, raw material mixed gas and reaction temperature, reaction pressure, conversion rate, yield and the like.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

As described above, in the method of the present invention, phosphorus tungstomolybdic acid, silicotungstomolybdic acid or a cesium salt or rubidium salt thereof,
Since at least one salt selected from the group consisting of thallium salt, ammonium salt and potassium salt is used as a catalyst, the space-time yield is high and the catalyst life is long.
There is an advantage that lower fatty acid esters such as acetic acid ester and acrylic acid ester can be efficiently produced.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location C07C 69/54 Z 8018-4H // C07B 61/00 300

Claims (1)

[Claims] 1. A lower fatty acid and a lower olefin are combined with phosphorus tungstomolybdic acid, silicotungstomolybdic acid, or cesium salt, rubidium salt, thallium salt, ammonium salt and potassium salt of phosphorus tungstomolybdic acid or silicotungstomolybdic acid. A method for producing a lower fatty acid ester, which comprises reacting in the presence of a catalyst of at least one salt selected from the group consisting of: