JPH0912492A - Production of 1,4-butanediol and/or tetrahydrofurane - Google Patents

Abstract

PURPOSE: To obtain 1,4-butanediol and/or tetrahydrofurane at a high yield by a catalytic hydrogenation using a specific acid or its mixture as a raw material and a specific catalyst having a high activity under relatively mild reaction conditions. CONSTITUTION: This method for producing 1,4-butanediol and/or tetrahydrofurane by a catalytic hydrogenetion using maleic anhydride, maleic acid, succinic anhydride, succinic acid, γ-butyrolactone or their mixtures in the presence of a hydrogenation catalyst obtained by loading ruthenium and tin on a carrier, comprises carrying out the reaction by flowing an excess hydrogen into the reaction system while removing the product accompanying with it to outside of the system.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention uses maleic anhydride, maleic acid, succinic anhydride, succinic acid, γ-butyrolactone or a mixture thereof as a raw material, and produces 1,4-butanediol and / or by a catalytic hydrogenation reaction. It relates to a method for producing tetrahydrofuran. 1,4-butanediol is
It is mainly used as a raw material for plastics such as polybutylene terephthalate and polyurethane, and is also used as a production intermediate for pyrrolidine and adipic acid. Tetrahydrofuran is used as a solvent because it has a low boiling point and an excellent dissolving power, and is also used as a raw material for polytetramethylene ether glycol, tetrahydrothiophene and the like.

[0002]

2. Description of the Related Art Heretofore, many methods have been reported for hydrogenating oxygen-containing C4 hydrocarbons such as maleic anhydride. For example, the best known method is to use a copper-based catalyst. However, in this method, an organic carboxylic acid such as maleic acid cannot be directly reduced, and the carboxylic acid must be once converted into an ester and then reduced, resulting in a long manufacturing process. Further, in this method, the reaction is generally carried out under a hydrogen pressure of 200 atm or higher, which is uneconomical in terms of energy and equipment.

On the other hand, some catalysts which can directly reduce carboxylic acids such as maleic acid have been proposed. For example, JP-A-63-218636 and US Pat.
No. 686 describes a method for producing tetrahydrofuran or γ-butyrolactone from an aqueous maleic acid solution using a palladium-rhenium catalyst supported on activated carbon. However, the method described in JP-A-63-218636 has a low reaction substrate concentration, and the method described in US Pat. No. 4,659,686 requires a hydrogen pressure of 150 atm or higher when carrying out the reaction. There is a drawback that

US Pat. No. 4,827,001 proposes a method for directly reducing maleic acid using ruthenium-iron oxide as a catalyst. In this method, 1,4-butane is used. The selectivity of diol, tetrahydrofuran and γ-butyrolactone is not sufficient. Thus, conventionally, in the hydrogenation reaction of maleic acid or the like, it has been necessary to carry out the reaction under relatively high hydrogen pressure conditions or low substrate concentration conditions in order to enhance the reactivity.

[0005]

Therefore, according to the present invention, 1,4-butanediol is hydrogenated by hydrogenating maleic acid or the like using a specific hydrogenation catalyst under mild conditions using a catalyst having high reaction activity. And / or a method for producing tetrahydrofuran, particularly by providing a production method by carrying out the reaction while removing the reaction product out of the system, and without decomposing the target product and obtaining the target product with high yield. The purpose is to

[0006]

In the present invention, maleic anhydride, maleic acid, succinic anhydride, succinic acid, γ-butyrolactone or a mixture thereof is used as a raw material, and ruthenium (Ru) and tin (Sn) are used as carriers. When 1,4-butanediol and / or tetrahydrofuran is produced by a catalytic hydrogenation reaction in the presence of a supported hydrogenation catalyst, excess hydrogen is passed through the reaction system to remove entrained products from the system. The method for producing 1,4-butanediol and / or tetrahydrofuran is characterized in that the reaction is carried out while removing it.

Hereinafter, the present invention will be described in detail. In the method of the present invention, maleic anhydride, maleic acid, succinic anhydride, succinic acid, γ-butyrolactone or a mixture thereof is used as a reaction raw material. In the method of the present invention, the (anhydrous) maleic acid is hydrogenated to (anhydrous) succinic acid, then γ-butyrolactone, and finally the final product, in view of the estimated reaction mechanism and the analysis result of the reaction product. It is presumed that the product produces 1,4-butanediol and / or tetrahydrofuran. Therefore, in the present invention, any of the above compounds can be used as a reaction raw material, and a mixture of two or more thereof may be used.

Ru-S employed in the method of the present invention
As the n-supporting hydrogenation catalyst, platinum (Pt), rhodium (Rh), or Ru to which both Pt and Rh (hereinafter referred to as "precious metal component") are added, a precious metal component and Sn are further supported on a carrier. Is preferred. As a carrier for the catalyst, a porous carrier such as activated carbon, diatomaceous earth, silica, alumina, titania, zirconia or the like can be used alone or in combination of two or more kinds.

The method for preparing these supported catalysts is not particularly limited, but the dipping method is usually used. In the case of the dipping method, for example, a catalyst raw material compound is dissolved in a solvent, for example, water to form a solution, and a separately prepared porous carrier is immersed in the solution to support the catalyst component on the carrier.

The order of loading each catalyst component on the carrier is not particularly limited, and all the metal components may be loaded simultaneously at the same time, each component may be loaded individually one by one, or some of the components may be loaded. The effect of the present invention can be achieved by combining the above and supporting the same a plurality of times. However, particularly, when Ru and Sn are first loaded on the carrier, and then at least one selected from Pt and Rh is additionally loaded on the carrier, the effect of the present invention can be further enhanced. The cause of improving the reaction activity by supporting at least one selected from Pt and Rh after Ru and Sn is not known in detail,
This is because these metals can be supported on the catalyst surface by supporting Pt or Rh, which has a high hydrogen activating ability or hydrogenation reaction activity, on the catalyst surface, and the metal on this surface effectively functions in the hydrogenation reaction. Presumed.

After the solution of the metal component is dipped and carried (whenever it is dipped and carried out a plurality of times, each time), it is dried. After that, firing and reduction are performed as necessary. When performing a baking process, it is usually performed in a temperature range of 100 to 600 ° C. Further, when performing the reduction treatment, a known liquid-phase reduction method or vapor-phase reduction method is adopted, and in the case of the vapor-phase reduction method, it is usually in the temperature range of 100 to 500 ° C., preferably 20.
It is performed in the range of 0 to 350 ° C. The details of the structure of the catalyst after the reduction treatment are unknown, but it is estimated that under the above-mentioned reducing conditions, substantially all of the noble metal component is reduced to metal, and Sn is partially Is divalent or 4
It is estimated that the price will remain.

The loading amounts of the noble metal component and Sn are respectively
It is usually 0.5 to 50% by weight, preferably 1 based on the carrier.
-20% by weight. It is preferable that Pt and / or Rh coexist in an amount of 0.01 to 10 times by weight relative to Ru from the viewpoint of improving the activity. It is preferable that Sn is present in an amount of usually 0.1 to 5 times by weight with respect to the noble metal component from the viewpoint of improving the selectivity of the product. As the raw material compound of the noble metal component and tin, nitric acid, sulfuric acid, hydrochloric acid and like mineral salts of these metals are generally used, but organic acid salts such as acetic acid, hydroxides, oxides or complex salts are also used. It can also be used.

In the method of the present invention, in the presence of the above-mentioned hydrogenation catalyst, the temperature is usually 130 to 350 ° C., preferably 160 to 300 ° C., the hydrogen pressure is 10 to 300 kg / cm ² ,
Preferably, under conditions of 50 to 200 kg / cm ^2, an excess of hydrogen over the amount consumed in the reaction is passed through the reaction system,
The reaction is carried out while entraining a part of the product together with hydrogen and removing it out of the system. This is carried out especially for the purpose of removing tetrahydrofuran outside the reaction system.

That is, when the produced tetrahydrofuran is present in the reaction system for a long period of time, the hydrogenolysis reaction of tetrahydrofuran proceeds to cause a decrease in the yield, and the increase in the partial pressure of tetrahydrofuran causes the partial pressure of hydrogen in the system to increase. However, there was a problem that the reaction rate was lowered and the reaction rate was lowered. Among them, the known catalysts have low activity and low activity of hydrogenolysis reaction of ethers, and the problem of decomposition of tetrahydrofuran was not remarkable, but Ru used in the present invention was used.
-Sn-based catalysts and the like are catalysts exhibiting remarkably high activity as compared with conventional catalysts, and are apt to cause a hydrocracking reaction of ethers. Therefore, the method of the present invention is effective while fully utilizing the ability of the catalyst. It is effective because it can obtain the target object.

The flow amount of hydrogen may be larger than the amount consumed in the reaction at the reactor inlet, that is, more than 5 mol times with respect to the reaction substrate, but if it is too large, energy will be lost. The specific amount of hydrogen used depends on the type of reactor used and the reaction conditions (substrate concentration, reaction temperature, composition of reaction mixture, etc.), but the entrainment efficiency is usually 7 to 200 relative to the reaction substrate. Molar times, especially 10 to 100 molar times are used. The amount of the catalyst used in the reaction is 0.1-5 with respect to 100 parts by weight of the reaction raw material such as maleic anhydride.
The amount is preferably 100 parts by weight, and more preferably 1 to 100 parts by weight, but can be arbitrarily selected within the range where a practical reaction rate can be obtained according to various conditions such as reaction temperature or reaction pressure.

The reaction system may be either a liquid phase suspension reaction or a fixed bed reaction. The reaction may be carried out without a solvent, or, if necessary, a type of solvent that does not adversely affect the reaction may be used. The solvent that can be used at this time is not particularly limited, but specifically, water; alcohols such as methanol, ethanol, octanol, and dodecanol; ethers such as dioxane and tetraethylene glycol dimethyl ether; other, hexane, cyclohexane, decalin And the like hydrocarbons.

The 1,4-butanediol and / or tetrahydrofuran produced in the reaction is separated and purified by a known method such as distillation. Unreacted raw materials remaining after the separation and purification or γ-butyrolactone as a reaction intermediate can be reused as a reaction raw material.

[0018]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. In the following, “%” indicates “% by weight”. Example 1 In a sample bottle having a volume of 50 ml, RuCl ₃ .3H ₂ O was added to 1.
811 g, 0.950 g of SnCl ₂ .2H ₂ O was weighed and put in each, and 3.6 ml of 5N-HCl aqueous solution was further put in to dissolve, and SiO ₂ (Fuji Davison product, special grade 12 specific surface area 679 m ² /
g, pore volume 0.37 ml / g) was added, and the mixture was shaken well. After that, the contents were transferred to a 100 ml eggplant-shaped flask, and the solvent water was removed at 60 ° C. and 25 mmHg in a rotary vacuum dryer, and the mixture was baked at 150 ° C. for 2 hours in a nitrogen atmosphere and then 300 ° C. in a hydrogen atmosphere. And reduced for 2 hours to prepare a catalyst of 7% Ru-5% Sn / SiO ₂ .

In a 200 ml capacity autoclave, water 35
A solution prepared by dissolving 15 g of maleic anhydride in g was charged, and then 4 g of the catalyst prepared by the above method was charged, 20 kg / cm ² of hydrogen was injected under stirring at room temperature, and the temperature was raised to 240 ° C. While maintaining the internal temperature of the autoclave at 240 ° C,
Hydrogen was injected under pressure to increase the hydrogen pressure to 70 kg / cm ² , and hydrogen was passed through the reactor outlet at 30 normal liters (Nl) / hour, and the reaction was carried out at this pressure for 2 hours. At this time, the total amount of hydrogen used was 20.6 times the mol of the reaction substrate. After completion of the reaction, the reaction product was analyzed by gas chromatography. The results are shown in Table 1.

Example 2 1.578 g of RuCl ₃ .3H ₂ O and H ₂ PtCl ₆ .6
H ₂ O to 0.451 g, the SnCl ₂ · 2H ₂ O 0.95
0 g, 5N-HCl aqueous solution (3.6 ml) and SiO ₂ (8.72 g) as a carrier were prepared in the same procedure as in Example 1 to give 6.1% Ru-1.7% Pt-5%.
A Sn / SiO ₂ catalyst was prepared. Using this catalyst, hydrogenation reaction of maleic anhydride was carried out in the same procedure as in the example described in Example 1. Table 1 shows the analysis results of the reaction products.

Comparative Example 1 Using the catalyst of Example 1, the hydrogen was not passed through (the hydrogen consumed was constantly supplemented and the total pressure in the system was kept at 70 kg / cm ² ), and the product was discharged to the outside of the system. The hydrogenation reaction of maleic anhydride was carried out by the same procedure as in the example described in Example 1 except that the above was not removed. Table 1 shows the analysis results of the reaction products.

Comparative Example 2 Using the catalyst of Example 2, the hydrogen was not passed through (the hydrogen consumed was constantly supplemented and the total pressure in the system was kept at 70 kg / cm ² ), and the product was discharged to the outside of the system. The hydrogenation reaction of maleic anhydride was carried out by the same procedure as in the example described in Example 1 except that the above was not removed. Table 1 shows the analysis results of the reaction products.

[0023]

[Table 1]

In Table 1, the following abbreviations are used. CML: maleic anhydride THF: tetrahydrofuran BDO: 1,4-butanediol

[0025]

According to the method of the present invention, maleic anhydride, maleic acid, succinic anhydride, succinic acid, γ-butyrolactone or a mixture thereof is used as a raw material, and catalytic hydrogenation is performed using a highly active specific catalyst. In carrying out the reaction under relatively mild reaction conditions, the target 1,4-butanediol and / or
Alternatively, tetrahydrofuran can be produced in a high yield, and its industrial utility value is extremely high.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area C07C 27/04 C07C 27/04

Claims (3)

[Claims] 1. Catalytic hydrogen in the presence of a hydrogenation catalyst comprising maleic anhydride, maleic acid, succinic anhydride, succinic acid, γ-butyrolactone, or a mixture thereof as a raw material and ruthenium and tin supported on a carrier. When producing 1,4-butanediol and / or tetrahydrofuran by a chemical reaction, excess hydrogen is circulated in the reaction system, and the reaction is carried out while removing entrained products out of the system. For producing 1,4-butanediol and / or tetrahydrofuran. 2. A catalyst comprising ruthenium, platinum and / or rhodium and tin supported on a carrier is used as a hydrogenation catalyst, and 1,4-butanediol and / or tetrahydrofuran are used in claim 1. Manufacturing method. 3. The 1,4-butanediol and / or tetrahydrofuran as claimed in claim 1 or 2, wherein the product that is removed from the reaction system along with hydrogen is mainly tetrahydrofuran. Manufacturing method.