JP2000178213A - Production of 1,4-butanediol and/or tetrahydrofuran - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce 1,4-butanediol and/or tetrahydrofuran useful as an organic solvent or the like stably at high yield a long term while broadening a feasible temperature range where reaction for forming the above product(s) is carried out by adopting a single metal oxide catalyst as a catalyst. SOLUTION: When reacting a fatty acid ester of 1,4-butanediol with water in the presence of a catalyst, a single metal oxide catalyst is used as a catalyst. It is preferable that the oxide catalyst is at least one kind selected from the group consisting of oxides of metal elements of groups IV, V and XIII (concretely alumina, zirconia, titania and niobium oxides) and the fatty acid ester is an acetate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing 1,4-butanediol and / or tetrahydrofuran. More specifically, the present invention relates to a method of reacting a fatty acid ester of 1,4-butanediol with water in the presence of a catalyst. The present invention relates to a novel method for producing 1,4-butanediol and / or tetrahydrofuran in a stable and high yield over a long period of time.

[0002]

2. Description of the Related Art 1,4-Butanediol and tetrahydrofuran are extremely useful substances as organic synthetic materials such as organic solvents and high molecular substances, and have been produced by various methods.

[0003] For example, as a method for producing tetrahydrofuran, a method of catalytically hydrogenating furan obtained by decarbonylation of furfural, a method of hydrogenating butynediol obtained from acetylene and formaldehyde to form butanediol, and then performing a dehydration cyclization. A method or a method of reacting 1,4-butanediol acetate with water in the presence of an acid catalyst is known. As a method for producing 1,4-butanediol, a method of hydrogenating butynediol, a method of hydrolyzing an acetate of 1,4-butanediol, and the like are known.

In a method of reacting an acetate of 1,4-butanediol with water in the presence of an acid catalyst, 1,4-butanediol and tetrahydrofuran can be produced simultaneously, and a method using sulfuric acid as a catalyst ( JP 52
-93762), a method using a cation exchange resin (JP-A-54-32409), a method using a composite oxide catalyst, for example, a method using activated clay (GB117).
0222) or a method using silica alumina (Japanese Patent Laid-Open No.
-95656).

[0005]

However, the conventional production methods for producing 1,4-butanediol and tetrahydrofuran from 1,4-butanediol acetate ester have drawbacks when using any of the catalysts. The improvement is desired. That is, in the method using sulfuric acid as a catalyst, high-concentration sulfuric acid is used, but under such high-sulfuric-acid concentration conditions, the reaction solution is significantly colored, and it is difficult to separate from the reaction product. There is a disadvantage that the reactor is corroded severely and the yield is low. Further, in the method using a cation exchange resin, the reaction cannot be carried out at a high temperature which is advantageous for the reaction, so that the activity is low, and the amount of water required for the reaction is large. There is a drawback that a large load is required for processing. Furthermore, the method using a composite oxide catalyst such as activated clay or silica-alumina has drawbacks such as low selectivity of the reaction, high separation cost due to the large amount of water required, and low yield. .

The present invention solves the above-mentioned conventional problems,
It is an object of the present invention to provide a method for producing 1,4-butanediol and / or tetrahydrofuran in a stable and high yield over a long period of time by reacting a fatty acid ester of 1,4-butanediol with water in the presence of a catalyst. And

[0007]

The process for producing 1,4-butanediol and / or tetrahydrofuran according to the present invention comprises:
A method for producing 1,4-butanediol and / or tetrahydrofuran by reacting a fatty acid ester of 1,4-butanediol with water in the presence of a catalyst, wherein a single metal oxide catalyst is used as a catalyst. And

That is, the present inventors have made intensive studies to solve the above-mentioned problems, and as a result, when producing 1,4-butanediol and / or tetrahydrofuran from a fatty acid ester of 1,4-butanediol and water, the catalyst was used as a catalyst. When a solid acid composed of a single metal oxide is used, the yield is improved as compared with the case where sulfuric acid or a composite oxide is used. The reaction can be performed at a wide range of reaction temperatures from low to high. There is no by-product formation. The catalyst does not deteriorate even at high temperature or for a long time. That is, since the catalyst does not have a strong acid point, catalyst degradation does not occur even if the reaction is continued. Since no mineral acid or the like is used, there is no danger of equipment corrosion, and high-grade materials are not required for the reactor. Even if the amount of water required for the reaction is reduced, the reaction proceeds completely, and the burden of subsequent water separation can be reduced. Heading that
The present invention has been completed.

As the single metal oxide catalyst used in the present invention, any one having an acidic point can be used, but preferably a single metal oxide belonging to Groups 4, 5, and 13 of the periodic table, More preferably, alumina, zirconia, titania, and niobium oxide are used.

As the fatty acid ester of 1,4-butanediol as a starting material, an acetate of 1,4-butanediol is preferred.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The single metal oxide catalyst used in the present invention is an oxide catalyst which does not correspond to a composite oxide, and any catalyst having an acidic point can be used. Group 5, Group 13, Group 13 single metal oxides, more preferably alumina, zirconia, titania,
And niobium oxide. These single metal oxide catalysts may be used alone or in combination of two or more.

Although such a single metal oxide is desirably as pure as possible, it may contain other elements as impurities. The content of these impurities is generally not more than 5%, preferably not more than 3%, more preferably not more than 1%, particularly preferably not more than 0.5% of the single metal oxide catalyst by weight.

The single metal oxide catalyst used in the present invention may have any specific surface area, but preferably has a large specific surface area (SA). For example, alumina is preferably 30 m ² / g or more, more preferably 50 m ² / g or more. Preferably not less than 10 m ² / g in the zirconia, 50 m ²
/ G or more is more preferable. In titania, 5
Those having m ² / g or more are preferable, and those having 20 m ² / g or more are more preferable.

The fatty acid ester of 1,4-butanediol used in the present invention is not particularly limited, and may be either a monoester or a diester. In particular, an ester of a saturated fatty acid having 2 to 4 carbon atoms is preferable. Esters are preferred.

The reaction of the present invention can be carried out by any of a batch system, a semi-batch system and a continuous system as in the conventional method.

The reaction of the present invention can be carried out in either a gas phase or a liquid phase, but it is advantageous to carry out the reaction in a gas phase.

The conditions for conducting the reaction in the gas phase will be described below.

When the reaction is carried out in the gas phase, generally, the raw material 1,4 is charged in a reaction column packed with a single metal oxide catalyst.
-A method of supplying a fatty acid ester of butanediol and water is employed.

In this case, 1,4-per unit catalyst capacity
Feed rate of fatty acid ester of butanediol (LHS
V) can vary over a wide range but is generally between 0.01 and 1000 hr ^-1 , preferably between 0.05 and 50 hr.
0 hr < ^-1 >, More preferably, it is 0.1-100 hr < ^-1 >.

The amount of water used in this reaction is not particularly limited, but is generally 0.01 to 100 times, preferably 0.1 times, the molar ratio to the fatty acid ester of 1,4-butanediol. ~ 50 times, more preferably 0.3 ~ 20
And especially preferably 0.5 to 15 times. In the present invention, by using a single metal oxide catalyst, 1,4-butanediol and / or tetrahydrofuran can be easily produced with a high conversion and a high selectivity even with a small amount of water as compared with a conventional catalyst. By performing the reaction with such a small amount of water, the amount of water remaining after the reaction can be extremely reduced, and the burden of subsequent separation of the product and water can be reduced.

In the present invention, the production ratio of 1,4-butanediol and tetrahydrofuran can be arbitrarily changed. 0.05 to 15 mole ratio, preferably 0.3 to 5 mole ratio, to the ester group which is equivalent to the fatty acid ester,
In particular, tetrahydrofuran can be easily produced at a high conversion and selectivity even with 0.5 mole ratio of water, which is industrially extremely advantageous.

On the other hand, when 1,4-butanediol is obtained as the main product, the amount of water must be at least 1 times the molar ratio of the ester group. In this case, the amount of water to be used may be any as long as it is at least 1 molar ratio to the ester group, but is preferably 1 to 100 times, more preferably 2 to 50 times.

The reaction temperature can be in a wide range, but is generally 50 to 350 ° C., preferably 150 to 350 ° C.
300 ° C. In the high-temperature reaction, the single metal oxide catalyst of the present invention hardly increases the by-products and deteriorates the catalyst even at a high temperature. The reaction is easily performed at a high temperature that is advantageous in speed.

The reaction pressure is not particularly limited, but is usually 0.01 to 1 MPa, preferably 0.03 to 0.8 MPa.
a, more preferably in the range of 0.05 to 0.5 MPa.

When the reaction is carried out in the gas phase, an inert gas such as nitrogen, argon or carbon dioxide may be used as a diluent gas in addition to the raw material fatty acid ester of 1,4-butanediol and water. it can.

Next, conditions for carrying out the reaction in the liquid phase will be described.

The amount of the catalyst used in the reaction is not particularly limited, but is generally 0.001 to 100 times, preferably 0.005 to 100 times by weight the fatty acid ester of 1,4-butanediol. 10 times, more preferably 0.01 to 1
Doubled.

This reaction may be performed without a solvent, or may be performed using a solvent. When a solvent is used, basically any solvent can be used as long as it does not adversely affect the reaction. Further, it is preferable to use a substance having a boiling point higher than that of tetrahydrofuran to be formed as a solvent, because the product can be easily separated. Specific examples of the solvent include (cyclic) aliphatic or aromatic hydrocarbons having 6 or more carbon atoms, aromatic halides such as chlorobenzene, ethers such as dimethoxyethane, alcohols such as propanol, N, Amides such as N-dimethylformamide and sulfoxides such as dimethyl sulfoxide can be used. Further, since the generated tetrahydrofuran has a lower boiling point than that of the raw material, a method of removing the product out of the reaction system by reactive distillation to cause the reaction while shifting the equilibrium of the reaction can also be suitably adopted.

The reaction time can be varied over a wide range but is generally from 0.01 to 50 hours, preferably from 0.1 to 50 hours.
It is for 0.5 to 20 hours, more preferably for 0.1 to 5 hours.

Other conditions in the liquid phase reaction conform to the reaction conditions in the gas phase reaction.

The thus obtained 1,4-butanediol and / or tetrahydrofuran is further purified by separating it from the raw material fatty acid ester, fatty acid such as acetic acid and water by distillation.

[0033]

The present invention will be described more specifically 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, “%” indicates “mol%”.

Example 1 Zirconia (manufactured by Norton, SA335m ² /
g, 10-20 mesh, purity 99.8% or more) 3 ml
Using a glass reactor filled with
At 0 ° C., 1,4-diacetoxybutane (1,4
-DAB) 8.1 mmol / hr, water 31.4 mmol
/ Hr (water / 1,4-DAB = 4), nitrogen 1.35 L /
hr was supplied at normal pressure.

The product liquid obtained from the bottom of the reactor was analyzed by GC (gas chromatography), and the following results were obtained (hereinafter, all analyzes used GC).

Conversion (1,4-diacetoxybutane): 84.2% Selectivity (tetrahydrofuran): 99.9% Further, no coloring was observed in the catalyst after the reaction, and the reaction was continued for 7 hours. No deterioration was observed. The product liquid after 7 hours was analyzed, and the following results were obtained.

Conversion (1,4-diacetoxybutane): 84.9% Selectivity (tetrahydrofuran): 99.9% Example 2 9.92 mmol / hr water (water / 1,4-DAB = 1.
2) Example 1 except that 0.73 L / hr of nitrogen was used.
The reaction was performed in the same manner as described above, and the product solution was analyzed in the same manner. The following results were obtained.

Conversion rate (1,4-diacetoxybutane): 74.2% Selectivity (tetrahydrofuran): 98.8% Further, no coloring was observed in the catalyst after the reaction, and the reaction was continued for 10 hours. No deterioration was observed.

Example 3 A reaction was carried out in the same manner as in Example 1 except that the temperature was changed to 280 ° C., and the product was analyzed in the same manner. The following results were obtained.

Conversion (1,4-diacetoxybutane): 99.7% Selectivity (tetrahydrofuran): 98.8% Further, no coloring was observed in the catalyst after the reaction, and the reaction was continued for 6 hours. No deterioration was observed.

Example 4 1,4-diacetoxybutane 3.42 mmol / hr,
Water 74.1 mmol / hr (water / 1,4-DAB = 2
2) The temperature was 160 ° C., and zirconia (manufactured by Norton, SA106 m ² / g, 1) was used as a single metal oxide catalyst.
The reaction was carried out in the same manner as in Example 1 except that 5 ml of 0 to 20 mesh (purity: 99.8% or more) was used, and the product was analyzed in the same manner, and the following results were obtained.

Conversion (1,4-diacetoxybutane): 16.3%
Selectivity (tetrahydrofuran + 1,4-butanediol): 99.4% Producing ratio (1,4-butanediol / tetrahydrofuran): 12.5 Further, no coloring was observed in the catalyst after the reaction, and the reaction was continued for 18 hours. No deterioration was observed.

Example 5 3.42 mmol / hr of 1,4-diacetoxybutane
(Water / 1,4-DAB = 9). As the single metal oxide catalyst, γ-alumina (SA250m ² / g, manufactured by Rhone Poulenc, 10-20 mesh, purity 9)
The reaction was carried out in the same manner as in Example 1 except that 5 ml (9.9% or more) was used, and the product was analyzed in the same manner, and the following results were obtained.

Conversion (1,4-diacetoxybutane): 99.6% Selectivity (tetrahydrofuran): 99.3% Further, no coloring was observed in the catalyst after the reaction, and the reaction was continued for 6 hours. No deterioration was observed.

Comparative Example 1 1,4-diacetoxybutane 3.46 mmol / hr,
9.92 mmol / hr of water (water / 1,4-DAB =
3), the temperature of 200 ° C., silica zirconia (ZrO ₂ 5 as a composite oxide catalyst in place of a single metal oxide catalysts
The reaction was carried out in the same manner as in Example 1 except that 3 ml (mol%, 10 to 20 mesh) was used, and the resulting solution was analyzed in the same manner.

Conversion (1,4-diacetoxybutane): 45.9% Selectivity (tetrahydrofuran): 100% In this case, the catalyst after the reaction is colored deeply, and the activity is deteriorated when the reaction is continued for 7 hours. Was. The product liquid after 5 hours was analyzed and the following results were obtained.

Conversion (1,4-diacetoxybutane): 38.1% Selectivity (tetrahydrofuran): 99.7% As is clear from the above Examples and Comparative Examples, a single metal oxide catalyst was used as the catalyst. In the production method of the present invention used, even when the reaction was carried out at a high temperature which is advantageous for the reaction rate, catalyst deterioration did not occur, and high conversion and selectivity were obtained (Example 1,
2, 3, 5). In addition, the amount of water is about 0.5 with respect to the ester group of the difatty acid ester of 1,4-butanediol.
Even when the molar amount was reduced to twice the molar amount (that is, water / 1,4-DAB = 1), high conversion and selectivity were obtained (Example 2). This means that the reaction product liquid hardly contains water, which indicates that the burden of water separation in the subsequent step is extremely light as compared with the conventional method. Also, if the conditions are changed,
4-butanediol can also be obtained as a main component (Example 4).

On the other hand, when the conventional composite oxide catalyst is used, the conversion is inferior and the yield is low, and there is a problem of catalyst deterioration due to long-term use (Comparative Example 1).

[0049]

As described in detail above, according to the present invention,
From a fatty acid ester of 1,4-butanediol and water, 1,
In producing 4-butanediol and / or tetrahydrofuran, the yield is improved by using a single metal oxide as a catalyst. The reaction can be performed at a wide range of reaction temperatures from low to high. No by-products are formed. Since the catalyst does not deteriorate even at a high temperature reaction, the catalyst can be used for a long time. Since no sulfuric acid or the like is used, it is not necessary to use a high-grade material for the reactor, so that an inexpensive reactor can be used. Even if the amount of water required for the reaction is reduced, the reaction proceeds completely, so that the burden of water separation after the reaction is reduced. Such as 1,4-butanediol and / or
Alternatively, tetrahitrofuran can be industrially advantageously produced.

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Claims (4)

[Claims] 1. A method for producing 1,4-butanediol and / or tetrahydrofuran by reacting a fatty acid ester of 1,4-butanediol with water in the presence of a catalyst, wherein a single metal oxide catalyst is used as a catalyst. A process for producing 1,4-butanediol and / or tetrahydrofuran, characterized by using 2. The method according to claim 1, wherein the single metal oxide catalyst is selected from group 4 of the periodic table.
The production of 1,4-butanediol and / or tetrahydrofuran according to claim 1, characterized in that it is at least one kind selected from the group consisting of oxides of Group 5 and Group 13 metal elements. Law. 3. The 1,4- catalyst according to claim 2, wherein the single metal oxide catalyst is one or more selected from the group consisting of alumina, zirconia, titania and niobium oxide. A method for producing butanediol and / or tetrahydrofuran. 4. The method for producing 1,4-butanediol and / or tetrahydrofuran according to claim 1, wherein the fatty acid ester is an acetic acid ester.