JP2022083663A - Method for producing alcohol - Google Patents

Abstract

To provide a method for producing an alcohol by hydration of an olefin with reduced formation of acetaldehyde and butene as by-products.SOLUTION: As a catalyst for alcohol production, used is a silica-carrying heteropoly acid catalyst with a total volume of pores with a pore size of 6 nm or less of 0.05 mL/g or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for producing an alcohol by a hydration reaction of an olefin.

Industrial ethanol is an important industrial chemical product widely used as an intermediate for organic solvents, organic synthetic raw materials, disinfectants, chemicals and the like. For industrial ethanol, liquid acids such as sulfuric acid and sulfonic acid, zeolite catalysts, metal oxide catalysts such as tungsten, niobium and tantalum, or heteropolyacids or phosphoric acids such as tonguestophosphoric acid and tonguestosilicic acid are used as silica carriers or diatomaceous earth carriers. It is known to be obtained by a hydration reaction of ethylene in the presence of a supported solid catalyst.

In the case of a liquid phase ethylene hydration reaction catalyzed by a liquid acid such as sulfuric acid or sulfonic acid, post-treatment of the acid used in the reaction is required, and in addition, there is a problem that the activity is low. , There were restrictions on industrial use. On the other hand, since the hydration reaction of ethylene using a carrier-supported solid catalyst can be carried out by a gas phase reaction, it is easy to separate the reactant and the catalyst, and the high temperature is advantageous in terms of reaction rate, or There is an advantage that the reaction can be carried out under high pressure conditions which are advantageous in terms of equilibrium theory.

Many proposals have been made for solid acid catalysts, and in particular, a gas phase reaction process using a solid acid catalyst in which phosphoric acid is supported on a carrier has already been industrially carried out. However, in an industrial process using a catalyst in which this phosphoric acid is carried on a carrier, the outflow of phosphoric acid, which is an active component, occurs continuously, and as a result, the activity and selectivity are reduced, and continuous phosphoric acid is produced. Supply was needed. In addition, since the outflowing phosphoric acid corrodes the equipment, regular maintenance of the reactor and other equipment is required, and there is a problem that the maintenance of the equipment is costly. In addition, the supported phosphoric acid catalyst causes physical and chemical deterioration of the catalyst due to contact with water vapor. After long-term use, the activity is reduced, and when the activity is severe, the carrier particles aggregate with each other to form a block, which may cause difficulty in replacing or extracting the catalyst. Therefore, in the ethylene hydration reaction, a novel carrier and a supported catalyst that solve these problems are being developed.

For example, there is known a hydration reaction of ethylene using a catalyst containing titanium oxide as a carrier and titanium oxide and tungsten oxide as essential components so that phosphoric acid does not flow out (see Patent Document 1).

Further, a method for producing ethanol by a hydration reaction of ethylene using a supported phosphoric acid catalyst in which phosphoric acid is supported on a silica carrier having an average pore volume of at least 1.23 mL / g is disclosed (Patent). See Document 2). According to the method disclosed in Patent Document 2, it is said that the yield and selectivity are excellent as compared with the conventional supported phosphoric acid catalyst, and the decrease in the particle strength of the carrier can be suppressed.

Further, as an ethanol production-supporting catalyst by a hydration reaction of ethylene with improved performance, a heteropolyacid-based catalyst in which a heteropolyacid is supported on fumed silica by a combustion method is disclosed (see Patent Document 3). As a method for improving the performance of a heteropolyacid catalyst, a catalyst in which a heteropolyacid is supported on a clay carrier treated with a hot acid has also been proposed (see Patent Document 4).

On the other hand, as a carrier of a supported catalyst suitable for an olefin hydration reaction, a silica carrier having a specific range of pore volume, specific surface area, and pore diameter is disclosed, and ethylene hydration using the carrier is disclosed. The production of ethanol by reaction is exemplified (see Patent Document 5).

However, in Patent Documents 1 to 5, caulking, which is one of the causes of catalyst deterioration, is caused by the outflow of the supporting component of the catalyst and the selectivity of ethylene hydration is poor, and by-products such as acetaldehyde and butene are used. The situation was not yet sufficient for industrial use, as the production was not sufficiently suppressed.

Japanese Unexamined Patent Publication No. 10-298122 Japanese Unexamined Patent Publication No. 10-101601 Japanese Unexamined Patent Publication No. 8-192047 Japanese Patent Application Laid-Open No. 8-225473 Japanese Patent Application Laid-Open No. 2003-190786

The present invention has been made in view of the above background, and an object of the present invention is to provide a method for producing an alcohol by a hydration reaction of an olefin in which the production of acetaldehyde and butene, which are by-products, is suppressed.

As a result of diligent studies, the present inventors have specified the total volume of pores of a specific size obtained by adjusting the amount of catalyst supported on the carrier material using a carrier material having an appropriate pore diameter. It has been found that the production of by-products can be significantly suppressed in the production of ethanol by the ethylene hydration reaction by using the silica-supported heteropolyacid catalyst in the range of the above, and the present invention has been completed.

That is, the present invention relates to the following [1] to [4].
[1]
A method for producing an alcohol, wherein the heteropolyacid or a salt thereof is hydrated with an olefin having 2 to 5 carbon atoms in the presence of a silica-supported heteropolyacid catalyst supported on a silica carrier to produce an alcohol.
The silica-supported heteropolyacid catalyst is a method for producing an alcohol, wherein the pore diameter is 6 nm or less and the total volume of pores is 0.05 mL / g or less.
[2]
The heteropolyacid is at least one selected from the group consisting of silicotung acid, phosphotungnic acid, phosphomolybdic acid, phytomolybdic acid, cavanadotungstate, limbanadotungsic acid, and limbanadomolybdic acid, [1]. The method for producing an alcohol according to.
[3]
The amount of the heteropolyacid or a salt thereof supported on the silica-supported heteropolyacid catalyst is 50 to 200 parts by mass with respect to 100 parts by mass of the silica carrier, according to any one of [1] and [2]. Production method.
[4]
The method for producing an alcohol according to any one of [1] to [3], wherein the olefin is ethylene and the alcohol is ethanol.

According to the present invention, a silica-supported heteropolyacid catalyst having a pore diameter of 6 nm or less and a total pore volume of 0.05 mL / g or less is used for producing an alcohol by a hydration reaction of an olefin, for example, ethylene. , The production of acetaldehyde and butene, which are by-products, can be suppressed.

It is a graph which shows the pore diameter distribution of the silica-supported heteropolyacid catalyst produced in an Example and a comparative example.

Hereinafter, preferred embodiments of the present invention will be described, but the present invention is not limited to these embodiments, and various applications are possible within the spirit and practice thereof.

<Alcohol manufacturing method>
The method for producing an alcohol according to an embodiment uses a solid acid catalyst in which a heteropolyacid or a heteropolylate is supported on a silica carrier (hereinafter, may be referred to as "catalyst for alcohol production") and water. This is a method for obtaining an alcohol by supplying an olefin having 2 to 5 carbon atoms to a reactor and allowing it to undergo a hydration reaction in a gas phase.

（式中、Ｒ^１～Ｒ^４は、それぞれ独立して、水素原子又は炭素原子数１～３のアルキル基を表し、Ｒ^１～Ｒ^４の合計の炭素原子数は０～３である。） A specific example of the alcohol production reaction by the hydration reaction of an olefin having 2 to 5 carbon atoms is shown in the following formula (1).

(In the formula, R ¹ to R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and the total number of carbon atoms of R ¹ to R ⁴ is 0 to 3).

The hydration reaction of the olefin using the alcohol production catalyst is an equilibrium reaction, and the conversion rate of the olefin is the equilibrium conversion rate at the maximum. For example, the equilibrium conversion rate in the production of ethanol by hydration of ethylene is calculated to be 7.5% at a temperature of 200 ° C. and a pressure of 2.0 MPaG. Therefore, in the method for producing alcohol by hydration of olefin, the maximum conversion rate is determined by the equilibrium conversion rate, and as seen in the example of ethylene, the hydration reaction of olefin tends to have a small equilibrium conversion rate. Industrially, there is a strong demand for highly efficient olefin hydration reaction under mild conditions.

The olefin having 2 to 5 carbon atoms applied to the method for producing an alcohol of one embodiment is not particularly limited. The olefin having 2 to 5 carbon atoms is, for example, ethylene, propylene, n-butene, isobutene, pentene, or a mixture of two or more thereof, and is preferably ethylene.

There is no limit to the ratio of olefin and water used, but the concentration of olefin depends on the reaction rate, and if the water concentration is high, the energy cost of the alcohol production process increases. The molar ratio is preferably water: olefin = 0.01 to 2.0, and more preferably water: olefin = 0.1 to 1.0.

There is no limitation on the type of hydration reaction of the olefin using the catalyst for alcohol production, and any reaction type can be used. Preferred types include, for example, a fixed bed type, a fluidized bed type, a suspension bed type, and the like from the viewpoint of ease of separation from the catalyst and reaction efficiency, and more preferably separation from the catalyst. It is a fixed floor type that requires the least energy.

The gas space velocity when the fixed bed type is used is not particularly limited, but is preferably 500 to 15,000 / hr, more preferably 1000 to 10000 / hr from the viewpoint of energy and reaction efficiency. If the gas space velocity is 500 / hr or more, the amount of catalyst used can be effectively reduced, and if it is 15,000 / hr or less, the gas circulation amount can be reduced. Alcohol can be produced more efficiently.

There is no limitation on the reaction pressure in the hydration reaction of the olefin using the catalyst for alcohol production. Since the hydration reaction of olefin is a reaction in which the number of molecules is reduced, it is generally advantageous to carry out the hydration reaction at high pressure. The reaction pressure is preferably 0.5 to 7.0 MPaG, more preferably 1.5 to 4.0 MPaG. Here, "G" means gauge pressure. If the reaction pressure is 0.5 MPaG or more, a sufficient reaction rate can be obtained, and if it is 7.0 MPaG or less, equipment related to olefin condensation measures and olefin evaporation is installed, and equipment related to high-pressure gas safety measures. It is not necessary to install the gas, and the cost related to energy can be further reduced.

The reaction temperature of the hydration reaction of the olefin using the alcohol production catalyst is not particularly limited and can be carried out in a wide range of temperatures. The preferred reaction temperature is 100 to 550 ° C, more preferably 150 to 350 ° C, considering the thermal stability of the heteropolyacid or heteropolylate and the temperature at which water, which is one of the raw materials, does not condense.

In the olefin hydration reaction using an alcohol production catalyst, the loss of the olefin can be reduced by recycling the unreacted olefin to the reactor. There is no limitation on the method of recycling the unreacted olefin to the reactor, and the olefin may be isolated and recycled from the process fluid coming out of the reactor, or may be recycled together with other inert components. Industrial grade ethylene usually contains very small amounts of ethane. Therefore, when recycling unreacted ethylene to a reactor using ethylene containing ethane, a part of the recovered ethylene gas should be purged to the outside of the system in order to prevent the concentration and accumulation of ethane. Is desirable.

In the hydration reaction of an olefin using a catalyst for producing an alcohol, the produced alcohol may be dehydrated to produce an ether compound as a by-product. For example, when ethanol is obtained by hydration of ethylene, diethyl ether is produced as a by-product. This diethyl ether is considered to be generated by a dehydration reaction from two molecules of ethanol, and when ethanol is produced by a hydration reaction of ethylene, the yield of the reaction is significantly reduced. By recycling the by-produced diethyl ether into a reactor, the diethyl ether is converted into ethanol, and ethanol can be produced from ethylene with extremely high efficiency. The method of recycling the by-produced ether compound into the reactor is not particularly limited, and for example, a method of isolating the ether compound from the components distilled from the reactor and recycling it into the reactor, a gas together with an unreacted olefin. As an ingredient, there is a method of recycling to a reactor.

<Silica-supported heteropolyacid catalyst (catalyst for alcohol production)>
In one embodiment of the method for producing an alcohol, silica is a solid acid catalyst in which a heteropolyacid or a salt thereof (also referred to as “heteropolyate” in the present disclosure) is supported on a silica carrier as a catalyst for alcohol production. A carrier heteropolyacid catalyst is used.

(Heteropolyacids, heteropolylates)
Heteropolyacids are acids consisting of a central element and peripheral elements to which oxygen is bound. The central element is usually silicon or phosphorus, but can be selected from any one selected from various elements of Groups 1 to 17 of the Periodic Table of the Elements.

Examples of the central element constituting the heteropolyacid include cupric ion; divalent beryllium, zinc, cobalt or nickel ion; trivalent boron, aluminum, gallium, iron, cerium, arsenic, antimony, phosphorus and bismuth. , Chromium or rhodium ions; tetravalent silicon, germanium, tin, titanium, zirconium, vanadium, sulfur, tellurium, manganese, nickel, platinum, thorium, hafnium, cerium ions and other rare earth ions; pentavalent phosphorus, Examples thereof include, but are not limited to, arsenic, vanadium, antimony ion; hexavalent tellurium ion; and heptavalent iodine ion.

Examples of peripheral elements constituting the heteropolyacid include, but are not limited to, tungsten, molybdenum, vanadium, niobium, tantalum and the like.

Such heteropolyacids are known as "polyoxoanions", "polyoxometal salts" or "metal oxide clusters". Some of the well-known structures of anions are named after the researchers in this field, for example, the Keggin-type structure, Wells-Dawson. A type structure and an Anderson-Evans-Perloff type structure are known. For details, refer to the description of "Chemistry of Polyacid" (edited by The Chemical Society of Japan, Quarterly Chemistry Review No. 20, 1993). Heteropolyacids are usually high molecular weight and have, for example, a molecular weight in the range of 700-8500 and include not only their monomers but also dimeric complexes.

The heteropolyate is a metal salt or an onium salt in which a part or all of the hydrogen atom of the above heteropolyacid is substituted. For example, metal salts of lithium, sodium, potassium, cesium, magnesium, barium, copper, gold, and gallium, and onium salts such as ammonia can be mentioned, but are not limited thereto.

Heteropolyacids have relatively high solubility in other protic solvents such as water or oxygenated solvents, especially if the heteropolyacid is in the form of a free acid or some salt. The solubility of heteropolyacids can be controlled by selecting the appropriate counterion.

Examples of the heteropolyacid that can be supported on the silica carrier as a catalyst include, but are not limited to, the following.
Chitungstic acid H ₄ [SiW ₁₂ O ₄₀ ] · xH ₂ O
Phosphor Tungstic Acid H ₃ [PW ₁₂ O ₄₀ ] · xH ₂ O
Phosphomolybic acid H ₃ [PMo ₁₂ O ₄₀ ] · xH ₂ O
Molybdic acid H ₄ [SiMo ₁₂ O ₄₀ ] · xH ₂ O
Keibanado Tungstic Acid H _{4 + n} [SiV _n W _12-n O ₄₀ ] · xH ₂ O
Limbanad Tungstic Acid H _{3 + n} [PV _n W _12-n O ₄₀ ] · xH ₂ O
Limbanado molybdic acid H _{3 + n} [PV _n Mo _12-n O ₄₀ ] · xH ₂ O
Keibanado molybdic acid H _{4 + n} [SiV _n Mo _12-n O ₄₀ ] · xH ₂ O
Keimoribdo Tungstic Acid H ₄ [SiMon W _{12-n O 40} ] · xH ₂ O
Phosphoribd Tungstic Acid H ₃ [PMon W _{12-n O 40} ] · xH ₂ O
(In the formula, n is an integer of 1 to 11 and x is an integer of 1 or more.)

As the heteropolyacid, silicotung acid, phosphotung acid, phosphomolybdic acid, phytomolybdic acid, cavanadotungstate, limbanadotungstate, or limbanadomolybdic acid is preferable, and phytonicic acid, phosphotungstate, and cyvanadotungsten Acids, or limbanadotungstates, are more preferred.

The method for synthesizing such a heteropolyacid is not particularly limited, and any method may be used. For example, a heteropolyacid can be obtained by heating an acidic aqueous solution (about pH 1 to pH 2) containing a salt of molybdenum acid or tungsten acid and a simple oxygen acid of a hetero atom or a salt thereof. The heteropolyacid compound can be isolated by crystallization separation as a metal salt from the generated heteropolyacid aqueous solution, for example.

A specific example of the production of heteropolyacids is 1413 of "New Experimental Chemistry Course 8 Synthesis of Inorganic Compounds (III)" (edited by The Chemical Society of Japan, published by Maruzen Co., Ltd., August 20, 1984, 3rd edition). It is described on the page, but is not limited to this. The structure of the synthesized heteropolyacid can be confirmed by X-ray diffraction, UV, or IR measurement in addition to chemical analysis.

Preferred examples of the heteropolylate salt include lithium salt, sodium salt, potassium salt, cesium salt, magnesium salt, barium salt, copper salt, gold salt, gallium salt, ammonium salt and the like of the above-mentioned preferred heteropolyacid.

Specific examples of the heteropolycatemate include lithium silicate of phytonic acid, sodium salt of silicate phosphite, cesium salt of silicate phosphite, copper salt of silicate phosphite, gold salt of silicate phosphite, and gallium salt of silicate phosphite. Lithium salt of phosphotung acid, sodium salt of phosphotung acid, cesium salt of phosphotung acid, copper salt of phosphotung acid, gold salt of phosphotung acid, gallium salt of phosphotung acid; lithium salt of phosphomolydic acid, Sodium salt of phosphomolybdic acid, cesium salt of phosphomolybdic acid, copper salt of phosphomolybdic acid, gold salt of phosphomolybdic acid, gallium salt of phosphomolybdic acid; lithium salt of silicate molybdic acid, sodium salt of phytomolybdic acid, kay. Cesium salt of molybdenum acid, copper salt of silicate molybdic acid, gold salt of silicate molybdic acid, gallium salt of silicate molybdic acid; lithium salt of cybanado tungstate, sodium salt of keibanado tungstate, cesium salt of keibanado tungstate , Copper salt of cavanado tungsten acid, gold salt of cavanado tungsten acid, gallium salt of cavanado tungsten acid; lithium salt of limbanado tungsten acid, sodium salt of limbanado tungsten acid, cesium salt of limbanado tungsten acid, limba Copper salt of nadtungstate, gold salt of limbanadotungstate, gallium salt of limbanadotungstate; lithium salt of limbanadomolybdic acid, sodium salt of limbanadomolybdenum, cesium salt of limbanadomolybdenum, limbanadomolybdenum Copper salt of acid, gold salt of limbanado molybdenum acid, gallium salt of limbanado molybdenum acid; lithium salt of keibanado molybdenum acid, sodium salt of keibanado molybdenum acid, cesium salt of keibanado molybdenum acid, cesium salt of keibanado molybdenum acid Examples thereof include a copper salt, a gold salt of cavanado molybdenum acid, and a gallium salt of cavanado molybdenum acid.

Heteropolylates include lithium phytonic acid, sodium phytonic acid, cesium cesium salt, cesium cesium salt, copper phytonic acid, gold phytonic acid, gallium phosphotung acid; phosphotungsten. Lithium salt of acid, sodium salt of phosphotung acid, cesium salt of phosphotung acid, copper salt of phosphotung acid, gold salt of phosphotung acid, gallium salt of phosphotung acid; lithium salt of phosphomolydic acid, phosphomolybdic acid Sodium salt, cesium salt of phosphomolybdic acid, copper salt of phosphomolybdic acid, gold salt of phosphomolybdic acid, gallium salt of phosphomolybdic acid; Cesium salt, copper salt of silicate molybdic acid, gold salt of cocoa molybdenate, gallium salt of cocoa molybdenum; lithium salt of keibanado tung acid, sodium salt of keibanado tung acid, cesium salt of keibanado tung acid, keibanado Copper salt of tungsten acid, gold salt of cavanado tungsten acid, gallium salt of cavanado tungsten acid; lithium salt of limbanado tungsten acid, sodium salt of limbanado tungsten acid, cesium salt of limbanado tungsten acid, limbanado tungsten acid Copper salt, gold salt of limbanado tungstate, gallium salt of limbanado tungstate; lithium salt of limbanado molybdenum, sodium salt of limbanado molybdenum, cesium salt of limbanado molybdenum, copper of limbanado molybdenum. Salts, gold salts of limbanado molybdenum acid, gallium salts of limbanado molybdenum acid; lithium salts of cybanado molybdenum acid, or sodium salts of cybanado molybdenum acid are preferred.

Heteropolylates include lithium silicate of silicate, sodium salt of silicate, cesium salt of cesium, copper salt of cesity, gold salt of silicate, gallium salt of phytonic acid; phosphotungsten. Lithium salt of acid, sodium salt of phosphotung acid, cesium salt of phosphotung acid, copper salt of phosphotung acid, gold salt of phosphotung acid, gallium salt of phosphotung acid; Sodium salt of tungsten acid, cesium salt of cavanado tungsten acid, copper salt of cavanado tungsten acid, gold salt of cavanado tungsten acid, gallium salt of cavanado tungsten acid; lithium salt of limbanado tungsten acid, limbanado tungsten acid Sodium salt, cesium salt of limbanado tungstate, copper salt of limbanado tungstate, gold salt of limbanado tungstate, or gallium salt of limbanado tungstate is more preferred.

As the heteropolymate, a lithium salt of caytungstic acid or a cesium salt of phosphotungstic acid is particularly suitable.

(Silica carrier)
The heteropolyacid or heteropolylate is used by supporting it on a silica carrier.

The silica used as the silica carrier is not limited, and for example, naturally obtained silica or synthetic silica obtained by synthesizing various silica raw materials can be used. Generally, synthetic amorphous silica is produced by either a dry method or a wet method. The combustion method of burning silicon tetrachloride in a hydrogen flame in the presence of oxygen is classified as a dry method, and the growth of primary particles is promoted by advancing the neutralization reaction of sodium silicate and mineral acid in the acidic pH range. The gel method that causes aggregation in a suppressed state, the sol gel method that hydrolyzes alkoxysilane, and the ion exchange of sodium silicate to prepare active silicic acid, and then the particles in the seed particle-containing aqueous solution whose pH is adjusted under heating. The water glass method for growing is classified as a wet method.

Generally, silica obtained by the combustion method is fumed silica gel, silica gel obtained by the gel method is silica gel, and silica obtained by dispersing silica particles obtained by the sol-gel method and water glass method in a medium such as water is used. It is called colloidal silica gel.

The silica carrier of one embodiment is obtained by kneading fumed silica obtained by a combustion method, silica gel obtained by a gel method, and colloidal silica obtained by a sol-gel method or a water glass method to obtain a kneaded product. It can be obtained by molding the obtained kneaded product into a molded product and then firing the molded product.

When fumed silica, silica gel, and colloidal silica are kneaded, molded, and fired, the primary and secondary particles of the silica carrier after firing depend on the mixing ratio of each component, kneading method, firing conditions, and the like. The size of the silica gel and the internal state of the porous body change. Therefore, the higher-order structure of the silica carrier cannot be defined. The composition formula of the silica carrier is SiO ₂ .

When fumed silica is used, there is no particular limitation, and general fumed silica can be used. Commercially available fumed silica includes, for example, Aerosil (trademark) (manufactured by Nippon Aerosil Co., Ltd.), Leolosil (trademark) (manufactured by Tokuyama Corporation), CAB-O-SIL (trademark) (manufactured by Cabot Corporation), etc. Can be mentioned. There are hydrophilic and hydrophobic grades of fumed silica on the market, but any of them can be used.

Typical fumed silica has, for example, a primary particle diameter of 7 to 40 nm and a specific surface area of 50 to 500 m ² / g as physical properties, is not porous, has no internal surface area, is amorphous, and is oxidized. It has a high purity of 99% or more as silicon and is characterized by containing almost no metal or heavy metal.

The silica gel is not particularly limited, and general silica gel can be used. Examples of commercially available silica gel include NIPGEL (manufactured by Tosoh Silica Co., Ltd.), MIZUKASIL (manufactured by Mizusawa Industrial Chemicals Co., Ltd.), CARiACT (manufactured by Fuji Silysia Chemical Ltd.), and Sunsphere (manufactured by AGC SI-Tech Co., Ltd.). And so on.

Generally, silica gel is prepared under acidic conditions by using sodium silicate obtained by dissolving sodium silicate glass (cullet) obtained by mixing and melting silica gel (SiO ₂ ) and soda ash (Na ₂ CO ₃ ) in water as a raw material. Below, it is produced by reacting the sodium silicate with a mineral acid such as sulfuric acid to cause aggregation in a state where the growth of primary particles is suppressed, and gelling the entire reaction solution.

The physical characteristics of silica gel are not particularly limited, but silica gel has the characteristics that the primary particles are small, the specific surface area is high, and the secondary particles are hard. Specific physical properties of silica gel include, for example, a BET specific surface area of 200 to 1000 m ² / g, a secondary particle diameter of 1 to 30 μm, and a pore volume by a nitrogen gas adsorption method (BJH method: Barrett, Joiner, Hallender method). Is 0.3 to 2.5 mL / g. The higher the purity of silica gel, the more preferable, and the preferable purity is 95% by mass or more, more preferably 98% by mass or more.

Colloidal silica is not particularly limited, and general colloidal silica can be used. Examples of commercially available colloidal silica include Snowtex (trademark) (manufactured by Nissan Chemical Co., Ltd.), Silica Doll (manufactured by Nippon Chemical Industrial Co., Ltd.), Adeleite (manufactured by ADEKA Co., Ltd.), and CAB-O-SIL (trademark). ) TG-C colloidal silica (manufactured by Cabot Corporation), Quattron (trademark) (manufactured by Fuso Chemical Industrial Co., Ltd.) and the like can be mentioned.

Colloidal silica is silica fine particles dispersed in a medium such as water. As a method for producing colloidal silica, there are a water glass method and a sol-gel method by hydrolyzing alkoxysilane, and colloidal silica produced by either production method can be used. Colloidal silica produced by the water glass method and colloidal silica produced by the sol-gel method may be used in combination.

Typical physical properties of colloidal silica include, for example, a particle size of 4 to 80 nm and a solid content concentration of silica dispersed in water or an organic solvent of 5 to 40% by mass. The concentration of impurities in colloidal silica is preferably low because it may affect the catalytically active component to be carried. The silica purity in the solid content is preferably 99% by mass or more, more preferably 99.5% by mass or more.

The silica carrier can be obtained by kneading fumed silica, silica gel, and colloidal silica to obtain a kneaded product, molding the obtained kneaded product into a molded product, and then firing the molded product. Appropriate additives may be added during kneading.

The blending ratio of fumed silica, silica gel, and colloidal silica is preferably 5 to 50 parts by mass of fumed silica, 40 to 90 parts by mass of silica gel, and 5 to 30 parts by mass of solid content of colloidal silica. More preferably, it is 15 to 40 parts by mass of fumed silica, 45 to 70 parts by mass of silica gel, and 5 to 15 parts by mass of solid content of colloidal silica.

When mixing fumed silica, silica gel, and colloidal silica, water or an additive can be added for the purpose of improving moldability, improving the strength of the final silica carrier, and the like. The additive is not particularly limited, and an additive used in producing a general ceramic molded product can be used. Depending on the purpose, a binder, a plasticizer, a dispersant, a lubricant, a wetting agent, an antifoaming agent and the like can be used.

Examples of the binder include wax emulsion, arabic rubber, lignin, dextrin, polyvinyl alcohol, polyethylene oxide, starch, methyl cellulose, Na-carboxymethyl cellulose, hydroxyethyl cellulose, sodium alginate, argin ammonium, traganth rubber and the like. Since the viscosity of the kneaded product changes greatly depending on the type and concentration of the binder, the type and amount of the binder are appropriately selected so that the viscosity is suitable for the molding method to be used.

Examples of the plasticizer include glycerin, polyethylene glycol, dibutyl phthalate and the like, and the plasticizer can enhance the flexibility of the kneaded product.

Examples of the dispersant include various amines such as ammonium carboxymethyl cellulose (CMC-NH ₄ ), an oligomer of acrylic acid or an ammonium salt thereof, an anionic surfactant, ammonium polycarboxylate, a wax emulsion, and monoethylamine. Examples thereof include pyridine, piperidine, tetramethylammonium hydroxide and the like. In the non-aqueous system, for example, fatty acids, fatty acid esters, phosphate esters, synthetic surfactants, benzenesulfonic acids and the like can be mentioned. By adding these dispersants, it is possible to obtain a silica carrier having a uniform fine structure after firing while avoiding the formation of aggregated particles.

Examples of the lubricant include liquid paraffin, paraffin wax, chlorinated hydrocarbon and the like in the hydrocarbon type, and fatty acid amide type and the like in the fatty acid type, for example, stearic acid, lauric acid and metal salts thereof. Can be mentioned. By adding the lubricant, the friction between the powders can be reduced, the fluidity can be improved, the molding can be facilitated, and the molded product can be easily removed from the mold.

Wetting agents can be added to improve the wetting properties of the silica powder and the dispersant. Examples of the wetting agent include nonionic surfactants, alcohols, glycols and the like in the aqueous system, and polyethylene glycol ethyl ether, polyoxyethylene ester and the like in the non-aqueous system. These substances are easily adsorbed on the solid-liquid interface and reduce the interfacial tension to improve the wetting of the solid.

When handling a slurry-based kneaded product, a defoaming agent such as a nonionic surfactant, a polyalkylene glycol-based derivative, or a polyether-based derivative can be added.

These additives can be used alone or in combination of two or more at the same time. As an additive, it is effective and inexpensive, it does not react with powder, it is soluble in water or solvent, and it is completely in an oxidizing or non-oxidizing atmosphere, for example, at a relatively low temperature of 400 ° C. or lower. It is desirable that ash, especially alkali metals and heavy metals, do not remain after decomposition and explosion, that the decomposition gas is not toxic and corrosive, and that it does not interfere with the recycling of unfinished debris.

The shape of the silica carrier is not particularly limited. For example, a spherical shape, a columnar shape, a hollow columnar shape, a plate shape, an elliptical shape, a sheet shape, a honeycomb shape and the like can be mentioned. It is preferably spherical, cylindrical, hollow cylindrical, or elliptical, and more preferably spherical or cylindrical (pellet-shaped), because it facilitates filling in the reactor and support of the catalytically active ingredient. be.

The particle size of the silica carrier is also not particularly limited. The particle size of the carrier varies depending on the form of the reaction, but when used in the fixed bed method, it is preferably 2 mm to 10 mm, more preferably 3 mm to 7 mm.

The method for molding the silica carrier is not particularly limited. It is molded from a kneaded product containing fumed silica, silica gel, and colloidal silica by any convenient method such as cast molding, extrusion molding, rolling granulation, spray drying and the like.

General mold molding involves putting the kneaded material in a metal mold, filling it well while hitting it with a mallet, etc., pressurizing it with a piston, and then removing it from the mold, which is also called stamp molding. .. Extrusion generally involves packing the kneaded material into a press, extruding it from a die, cutting it to a suitable length and forming it into a desired shape. Rolling granulation involves dropping the kneaded material onto a rotating disk placed at an angle and rolling the granules on the disk to grow them into a spherical shape. Spray drying generally involves spraying a thick slurry into hot air to obtain porous particles, although it does not result in very large particles.

The size of the silica carrier is not particularly limited. Since it affects the handling at the time of manufacturing or filling the catalyst carrying the catalytically active component, the differential pressure after filling in the reactor, the reaction performance of the catalytic reaction, etc., it is desirable to make the size in consideration of these. Since the silica carrier shrinks when the molded product is fired, the size of the silica carrier is determined by the firing conditions.

When the silica carrier is spherical, the size of the silica carrier (after firing) is preferably 0.5 mm to 12 mm, more preferably 1 mm to 10 mm, and 2 mm to 8 mm in diameter. Is more preferable. When the silica carrier has a non-spherical shape, the size of the silica carrier (after firing) is preferably 0.5 mm to 12 mm, which is the maximum dimension when the size is measured, and is preferably 1 mm to 1 mm. It is more preferably 10 mm, further preferably 2 mm to 8 mm.

When the particle size of the silica carrier is 0.5 mm or more, it is possible to prevent a decrease in productivity during carrier production and an increase in pressure loss when used as a catalyst. When the particle size of the silica carrier is 12 mm or less, it is possible to prevent a decrease in the reaction rate due to the rate-determining diffusion in the carrier and an increase in by-products.

Before or after firing, a treatment using Malmölizer (registered trademark) (manufactured by Fuji Powder Co., Ltd.) or the like may be performed to adjust the shape of the silica carrier, if necessary. For example, by treating a columnar molded body before firing with the Malmö riser (registered trademark), it can be molded into a spherical shape.

The calcination method is not particularly limited, but there is an appropriate calcination temperature range from the viewpoint of decomposing additives and preventing structural destruction of silica. The firing temperature is preferably 300 ° C to 1000 ° C, more preferably 500 ° C to 900 ° C. When the calcination temperature is in this range, the additive is completely decomposed and the performance of the silica carrier is not adversely affected. It also improves the specific surface area of the silica carrier.

The firing treatment can be carried out under either oxidizing or non-oxidizing conditions. For example, the firing treatment may be performed in an air atmosphere or in an inert gas atmosphere such as nitrogen gas. The time of the firing treatment is also not particularly limited, and can be appropriately determined according to the shape and size of the molded product, the type and amount of the additive used, and the like.

The average pore diameter of the mesopores obtained by the gas adsorption method of the silica carrier (BJH method: Barrett, Joiner, Hallender method) is preferably 5 to 16 nm. The average pore diameter of the mesopores obtained by the gas adsorption method (BJH method) of the silica carrier is more preferably 6 to 14 nm, still more preferably 7 to 12 nm. When the average pore diameter of the mesopores by the gas adsorption method (BJH method) of the silica carrier is in the range of 5 to 16 nm, the specific surface area by the BET method becomes a sufficient value.

The specific surface area (BET specific surface area) of the silica carrier by the BET method is preferably 200 to 500 m ² / g. The BET specific surface area of the silica carrier is more preferably 220 to 400 m ² / g, still more preferably 240 to 400 m ² / g. When the BET specific surface area of the silica carrier is in the range of 200 to 500 m ² / g, a sufficient reaction rate can be obtained when catalyzed.

The bulk density of the silica carrier is preferably 300 to 700 g / L. The bulk density of the silica carrier is more preferably 400 to 650 g / L, still more preferably 450 to 600 g / L. When the bulk density of the silica carrier is in the range of 300 to 700 g / L, a required amount of the active ingredient can be supported and the strength of the carrier can be maintained.

(Method for supporting a heteropolyacid on a silica carrier)
The method for supporting the heteropolyacid or a salt thereof on the silica carrier is not particularly limited. Generally, it can be carried out by dissolving or suspending a heteropolyacid or a salt thereof in a solvent, allowing the obtained solution or suspension to be absorbed by a carrier, and then evaporating the solvent.

Examples of the method of supporting the heteropolyacidate on the carrier include a method of supporting the raw material of the element forming the salt after supporting the heteropolyacid on the carrier, and a method of supporting the raw material of the heteropolyacid and the element forming the salt together on the carrier. Examples thereof include a method of supporting a heteropolyacidate prepared in advance on a carrier, a method of supporting a raw material of an element forming a salt on a carrier, and then a method of supporting a heteropolyacid, but the present invention is not limited thereto. do not have. In any of the above methods, the heteropolyacid, its salt, and the raw material of the element forming the salt can be dissolved or suspended in a suitable solvent and supported on a carrier. The solvent used at this time may be any one that can dissolve or suspend the heteropolyacid, its salt, or the raw material of the element forming the salt, and for example, water, an organic solvent, or a mixture thereof is preferably used. Water, alcohol, or a mixture thereof is used.

(Amount of heteropolyacid carried on silica carrier)
The amount of the heteropolyacid or its salt supported on the silica carrier can be adjusted, for example, by dissolving the heteropolyacid or its salt in distilled water corresponding to the amount of water absorbing liquid of the carrier and impregnating the carrier with the solution. can.

In another embodiment, the amount of the heteropolyacid or salt carried on the silica carrier is such that the silica carrier is immersed in an excess amount of a solution of the heteropolyacid or salt thereof with moderate movement and then filtered for excess. It can also be adjusted by removing the heteropolyacid or a salt thereof.

The volume of the solution or suspension varies depending on the carrier used, the supporting method, and the like. A silica-supported heteropolyacid catalyst, which is a solid acid catalyst supported on the carrier, can be obtained by evaporating the solvent of the carrier impregnated with the heteropolyacid or a salt thereof in a heating oven for several hours. The drying method is not particularly limited, and various methods such as a stationary type and a belt conveyor type can be used. Further, the amount of the heteropolyacid or its salt supported on the carrier can be accurately measured by chemical analysis such as ICP and XRF.

The amount of the heteropolyacid or its salt carried on the carrier is preferably 10 to 300 parts by mass, preferably 50 to 200 parts by mass, based on 100 parts by mass of the silica carrier. Is more preferable, and 80 to 130 parts by mass is further preferable.

(Total volume of pores with a pore diameter of 6 nm or less)
Since the pores of the silica carrier are closed as the amount of the heteropolyacid supported increases, it is possible to control the pore size distribution of the silica-supported heteropolyacid catalyst by adjusting the amount of the heteropolyacid supported.

In the silica-supported heteropolyacid catalyst, the total volume per 1 g of the silica-supported heteropolyacid catalyst of the pores having a pore diameter of 6 nm or less by the gas adsorption method (BJH method: Barrett, Joiner, Hallender method) is 0.05 mL / g or less. be. The total volume is more preferably 0.04 mL / g or less, still more preferably 0.02 mL / g or less.

The total volume of the pores having a diameter of 6 nm or less by the gas adsorption method (BJH method) can be measured by the method described in Examples.

It is considered that the pores having a pore diameter of 6 nm or less have poor diffusibility of the produced ethanol and ethylene as a substrate. Therefore, by reducing the pores having a pore diameter of 6 nm or less, the diffusivity of ethanol or ethylene to the outside of the catalyst is improved, which leads to a reduction in the residence time in the catalyst, and as a result, it is produced by the sequential reaction of ethanol. The production of by-products such as butene produced by the dimerization of acetaldehyde and ethylene is suppressed.

The present invention will be further described with reference to the following examples and comparative examples, but these examples and the like show the outline of the present invention, and the present invention is not limited to these examples and the like. do not have.

(Measuring method of pore diameter of silica-supported heteropolyacid catalyst)
The pore distribution was measured by the BJH method. Specifically, the pore size distribution of the silica-supported heteropolyacid catalyst by nitrogen gas adsorption was measured using a gas adsorption device (TriStar3000, manufactured by Shimadzu Corporation).

(Analysis of the total volume of pores with a pore diameter of 6 nm or less)
By the BJH method, at the same time as the measurement of the pore distribution, the total volume per 1 g of the catalyst of the pores having a pore diameter of 6 nm or less was analyzed.

(Analysis of reaction gas)
The sampled gas was analyzed using a gas chromatography device (device name: 7890, manufactured by Agilent) by a system program with a plurality of columns and two detectors under the following conditions.
-Gas chromatography conditions:
Oven: Hold at 40 ° C for 3 minutes, then heat up to 200 ° C at 20 ° C / min Carrier gas: Helium Split ratio: 10: 1
-Column used: HP-1 (2m) + GasPro (30m) 32m x 320μm x 0μm manufactured by Agilent Technologies
DB-624: 60m x 320μm x 1.8μm
·Detector:
Front detector: FID (heater: 230 ° C, hydrogen flow rate 40 mL / min, air flow rate 400 L / min)
Back detector: FID (heater: 230 ° C, hydrogen flow rate 40 mL / min, air flow rate 400 L / min)
Aux detector: TCD (heater: 230 ° C, reference flow rate 45 mL / min, make-up flow rate 2 mL / min)

(Analysis of reaction solution)
The sampled reaction solution was analyzed using a gas chromatography device (device name: 6850, manufactured by Agilent). The water concentration in the reaction solution was analyzed with a Karl Fischer analyzer manufactured by Mitsubishi Chemical Corporation.
-Column used: PoraBONDQ 25m x 0.53mm ID x 10μm
・ Oven temperature: After holding at 100 ℃ for 2 minutes, raise the temperature to 240 ℃ at 5 ℃ / min ・ Injection temperature: 250 ℃
・ Detector temperature: 300 ℃

(Calculation method of reaction results)
The ethanol air-time yield, ethanol selectivity, acetaldehyde selectivity, and butene selectivity were calculated by the following formulas.
Ethanol airtime yield (kg / h / m ³ ) = (mass of ethanol produced per hour) / (volume of catalyst used)
Ethanol selectivity (%) = (number of moles of ethanol produced / number of moles of ethylene supplied) x 100
Acetaldehyde selectivity (mol%) = (number of moles of acetaldehyde produced / number of moles of ethylene supplied) x 100
Butene selectivity (mol%) = (number of moles of butene produced / number of moles of ethylene supplied) x 100
The amount of butene was the total amount of 1-butene and 2-butene.

<Example 1>
(Preparation of silica carrier A)
Fumed silica (Aerosil ™ 300, manufactured by Nippon Aerosil Co., Ltd.) 40 parts by mass, silica gel (CARIACT G8, manufactured by Fuji Silicia Chemical Co., Ltd.) 60 parts by mass, and colloidal silica (Snowtex O, manufactured by Nissan Chemical Co., Ltd.) ) After kneading 40 parts by mass with water, methylcellulose (SM-4000, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) as an additive, and a resin-based binder (Selander (registered trademark) YB-132A, Yuken Kogyo Co., Ltd.) (Manufactured) was put into a kneader in an appropriate amount and further kneaded to prepare a kneaded product.

Next, the prepared kneaded product was put into an extrusion molding machine equipped with a die having a circular hole of 3 mmφ at the tip. An intermediate product extruded from the extruder was cut with a cutter so as to have a length of 3 mm to obtain a columnar pre-baking molded product. The obtained pre-baked molded body is formed into a spherical shape with Malmöllizer (registered trademark), pre-dried at 70 ° C., and then fired at a temperature of 820 ° C. in an air atmosphere to obtain silica carrier A. Got

(Measurement of water absorption rate of silica carrier A)
The water absorption rate of the obtained silica carrier A was measured by the following method.
(1) About 5 g of the carrier was weighed (W1 (g)) with a balance and placed in a 100 mL beaker.
(2) About 15 mL of pure water (ion-exchanged water) was added to the beaker so as to completely cover the carrier.
(3) It was left for 30 minutes.
(4) The carrier and pure water were poured over the wire mesh, the pure water was drained by the wire mesh, and the carrier was taken out.
(5) The water adhering to the surface of the carrier was lightly pressed with a paper towel until the surface became dull to remove it.
(6) The total mass of the carrier + pure water obtained in (5) was measured (W2 (g)).
(7) The water absorption rate of the carrier was calculated using the following formula.
Water absorption rate (g-water / g-carrier) (%) = (W2-W1) / W1 × 100
Therefore, the water absorption amount (g) of the carrier can be calculated by "water absorption rate of the carrier (g-water / g-carrier) (%) x mass (g) of the carrier used".

(Preparation of silica-supported heteropolyacid catalyst 1)
Weigh 15.0 g of commercially available Keggin-type silicotuntic acid / 26 hydrate (H ₄ SiW ₁₂ O ₄₀ / 26H ₂ O, manufactured by Nippon Inorganic Chemical Industry Co., Ltd.) in a 100 mL beaker, and add a small amount of distilled water. After dissolving, the solution was transferred to a 200 mL graduated cylinder. Next, distilled water was added so that the amount of the silica tung acid solution in the measuring cylinder was 95% of the water absorption rate of the silica carrier A to be carried, and the mixture was stirred so as to be uniform as a whole. After stirring, the aqueous solution of silicotung acid is transferred to a 200 mL volumetric flask, and then 30 mL (about 16 g) of silica carrier A is put into the 200 mL volumetric flask so that the aqueous solution of silicate carrier is spread over the entire carrier. Was mixed in a volumetric flask, and silicotung acid was supported on the silica carrier A. The silica carrier A carrying the silicotungstic acid was transferred to a magnetic dish, air-dried for 1 hour, and then dried in a hot air dryer adjusted to 130 ° C. for 5 hours. After drying, the mixture was transferred into a desiccator and cooled to room temperature to obtain a silica-supported heteropolyacid catalyst 1.

(Heteropolymetalate carrier amount)
Table 1 shows the supported amount of the heteropolyacid (caytungstic acid) per 100 parts by mass of the carrier, assuming that the entire amount of the heteropolyacid used for the preparation is supported.

(Measurement of pore size distribution)
The pore size distribution of the obtained silica-supported heteropolyacid catalyst 1 was measured by the above method. The results are shown in FIG.

(Analysis of the total volume of pores with a pore diameter of 6 nm or less)
For the obtained silica-supported heteropolyacid catalyst 1, the total volume per 1 g of the catalyst having pores having a pore diameter of 6 nm or less was analyzed by the above method. The results are shown in Table 1.

(Hydration reaction of ethylene)
30 mL of the obtained silica-supported heteropolymetalate catalyst 1 was weighed, filled in a vertical gas phase fixed bed reactor manufactured by SUS, replaced with nitrogen gas, and then the pressure was increased to 2.0 MPaG. Next, the reactor was heated to 180 ° C., and when the temperature became stable, the GHSV (Gas Whole Space Velocity) was 3000 / hr and the molar ratio to ethylene was 0.3, and the amount of water vaporized by the evaporator was increased. , Ethylene was fed to the reactor to carry out a hydration reaction of ethylene.

(Calculation of reaction results)
After feeding water and ethylene, after the temperature became stable, the temperature of the reactor was adjusted so as to have the target average temperature of the catalyst layer shown in Table 1. After 2 hours when the temperature became stable, the gas passing through the reactor was cooled, and the condensed liquid (reaction liquid) and the reaction gas from which the condensed liquid (reaction liquid) had been removed were sampled for 1 hour each. The obtained condensate (reaction solution) and reaction gas were analyzed by the above methods, respectively, and the reaction results of the silica-supported heteropolyacid catalyst 1 were calculated from the mass, the gas flow rate, and the analysis results. The results are shown in Table 1.

<Example 2>
(Preparation of silica carrier B)
Natural silica powder (purity 99.0%, average pore diameter 8 nm), methyl cellulose SM-4000 as an additive, manufactured by Shin-Etsu Chemical Co., Ltd., and a resin-based binder (Selander (registered trademark) YB-132A, Yuken Kogyo) (Made by Co., Ltd.) was added to prepare a kneaded product, which was rolled and granulated into a 3 mm spherical shape, and calcined at 650 ° C. in an air atmosphere. B was prepared. Moreover, the water absorption rate of the silica carrier B was measured by the same method as in Example 1.

(Preparation of silica-supported heteropolyacid catalyst 2)
A silica-supported heteropolyacid catalyst 2 was prepared in the same manner as the silica-supported heteropolyacid catalyst 1 except that 30 mL (about 18 g) of the silica carrier B was used.

For the obtained silica-supported heteropolyacid catalyst 2, the heteropolyacid-supported amount was calculated by the same method as in Example 1, the pore size distribution was measured, and the total volume of pores having a pore size of 6 nm or less was analyzed. .. Subsequently, a hydration reaction of ethylene was carried out in the same manner as in Example 1, and the reaction results were evaluated. The results are shown in Table 1.

<Example 3>
(Preparation of silica carrier C)
As the silica carrier C, 30 mL (about 19 g) of silica gel (Carrieract G6, manufactured by Fuji Silysia Chemical Ltd.) was used, and the water absorption rate of the silica carrier C was measured by the same method as in Example 1.

(Preparation of silica-bearing heteropolyacid catalyst 3)
A silica-supported heteropolyacid catalyst 3 was prepared in the same manner as in Example 1 except that the silica carrier C was used and 22.7 g of silicotungonic acid / 26 hydrate was used.

For the obtained silica-supported heteropolyacid catalyst 3, the heteropolyacid-supported amount was calculated in the same manner as in Example 1, the pore size distribution was measured, and the total volume of pores having a pore size of 6 nm or less was analyzed. .. Subsequently, a hydration reaction of ethylene was carried out in the same manner as in Example 1, and the reaction results were evaluated. The results are shown in Table 1.

<Comparative Example 1>
(Preparation of silica carrier C)
The same silica carrier C as in Example 3 was prepared.

(Preparation of silica-supported heteropolyacid catalyst 4)
A silica-supported heteropolyacid catalyst 4 was prepared in the same manner as in Example 1 except that the silica carrier C was used.

For the obtained silica-supported heteropolyacid catalyst 4, the heteropolyacid-supported amount was calculated by the same method as in Example 1, the pore size distribution was measured, and the total volume of pores having a pore size of 6 nm or less was analyzed. .. Subsequently, a hydration reaction of ethylene was carried out in the same manner as in Example 1, and the reaction results were evaluated. The results are shown in Table 1.

The present invention provides an alcohol production method by a olefin hydration reaction using a silica-supported heteropolyacid catalyst having a pore diameter of 6 nm or less and a total pore volume of 0.05 mL / g or less. It can reduce the production of by-products and is industrially useful.

Claims (4)

A method for producing an alcohol, wherein the heteropolyacid or a salt thereof is hydrated with an olefin having 2 to 5 carbon atoms in the presence of a silica-supported heteropolyacid catalyst supported on a silica carrier to produce an alcohol.
The silica-supported heteropolyacid catalyst is a method for producing an alcohol, wherein the pore diameter is 6 nm or less and the total volume of pores is 0.05 mL / g or less. The heteropolyacid is at least one selected from the group consisting of silicotung acid, phosphotungnic acid, phosphomolybdic acid, phytomolybdic acid, cavanadotungstate, limbanadotungstate, and limbanadomolybdic acid, claim 1. The method for producing an alcohol according to. The method for producing an alcohol according to any one of claims 1 or 2, wherein the amount of the heteropolyacid or a salt thereof supported on the silica-supported heteropolyacid catalyst is 50 to 200 parts by mass with respect to 100 parts by mass of the silica carrier. .. The method for producing an alcohol according to any one of claims 1 to 3, wherein the olefin is ethylene and the alcohol is ethanol.

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