Method for producing alcohol

Abstract

The present invention relates to a method for producing an alcohol by which alcohol can be more selectively obtained by improving an alcohol selectivity in a method for producing an alcohol from a synthetic gas. This method for producing an alcohol comprises the following steps 1 and 2. Step 1: a catalyst producing step for mixing, in a protic solvent, a cobalt-containing compound (a) and a copper-containing compound (b) soluble in the protic solvent so that the amount of copper relative to 1 mol of cobalt is 0.2-0.7 mol inclusive, reacting the mixture with a di- or poly-carboxylic acid compound (c), and obtaining a catalyst from the reaction product; step 2: an alcohol producing step for reacting a synthetic gas in the presence of the catalyst obtained in step 1 to obtain an alcohol.

Description

Alcohol production method

[0001] The present invention relates to a method for producing an alcohol, a method for producing a catalyst, and its use for producing an alcohol.

[0002] Syngas, a mixture of carbon monoxide and hydrogen, is one of the basic raw materials in C1 chemistry and is produced by using steam from coal, natural gas, heavy oil, petroleum exhaust gas, oil shale, biomass, etc. The composition of the syngas thus obtained is adjusted depending on its intended use, and it is used in technologies for producing organic compounds from syngas, such as the Fischer-Tropsch reaction (FT reaction). The inventors focused on a technology for producing alcohol from syngas as an application of this technology.

[0003] One such technique involves the reaction of CO and H in the presence of a cobalt-containing catalyst. ２ A method for producing alcohol by reacting a synthesis gas containing

[0004] Patent Document 1 discloses a catalyst for producing alcohol, which is a SiO 2 of a cobalt and copper compound. ２ A catalyst using a supported catalyst is disclosed, and a method for producing alcohol from synthesis gas using this catalyst is also disclosed. Non-Patent Documents 1 and 2 disclose a composite catalyst containing cobalt and copper as a catalyst for producing alcohol, and a method for producing alcohol from synthesis gas using this catalyst.

[0005] Chinese Patent Publication No. 102319575

[0006] ACS Catalysis, 2015, Vol.5, No.5, p2929-2934ACS Catalysis, 2014, Vol.4, No.8, p2792-2800

[0007] In recent years, efforts to achieve carbon neutrality have been progressing in many countries, and efforts to develop alternative fuels to reduce carbon dioxide emissions from conventional fossil fuels are attracting attention. ２There is a method for producing alcohol using a synthesis gas containing the above-mentioned amines as a raw material. As a method for producing alcohol using a synthesis gas as a raw material, alcohol can be produced by a catalytic reaction using the above-mentioned catalyst. However, in such a catalytic reaction, the proportion of alcohol produced in the reaction product (alcohol selectivity) is insufficient. Even in the disclosures of Patent Document 1 and Non-Patent Documents 1 and 2, the alcohol selectivity in alcohol production using the catalysts remains low.

[0008] The present invention is a method for producing a compound of CO and H ２ The present invention relates to a method for producing alcohol from a synthesis gas containing toluene, which can improve alcohol selectivity and more selectively obtain alcohol.

[0009] The present inventors have found that a catalyst obtained from the reaction product obtained by using a cobalt-containing compound and a copper-containing compound, both of which are soluble in a protic solvent, as raw material compounds in a predetermined ratio with a precipitant containing a divalent or higher carboxylic acid compound in a protic solvent can improve alcohol selectivity when producing alcohol from synthesis gas.

[0010] That is, the present invention relates to the following [1] to [3]. [1] A method for producing an alcohol, comprising the following steps 1 and 2: Step 1: A catalyst production step in which, in a protic solvent, a cobalt-containing compound (a) and a copper-containing compound (b) soluble in the protic solvent are mixed so that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol, and the resulting mixture is reacted with a divalent or higher carboxylic acid compound (c), to obtain a catalyst from the reaction product; Step 2: An alcohol production step in which a synthesis gas is reacted in the presence of the catalyst obtained in step 1 to obtain an alcohol; [2] A catalyst production method in which, in a protic solvent, a cobalt-containing compound (a) and a copper-containing compound (b) soluble in the protic solvent are mixed so that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol, and the resulting mixture is reacted with a divalent or higher carboxylic acid compound (c), to obtain a catalyst from the reaction product. [3] A cobalt-containing compound (a) and a copper-containing compound (b), both soluble in the protic solvent, are mixed in a protic solvent such that the amount of copper per 1 mol of cobalt is 0.2 mol or more and 0.7 mol or less, and reacted with a divalent or higher carboxylic acid compound (c), and use of a catalyst obtained from the reaction product to produce an alcohol by reacting carbon monoxide and hydrogen in a synthesis gas.

[0011] According to the present invention, there are provided a method for producing alcohol from a synthesis gas, which can improve alcohol selectivity and enable more selective production of alcohol, a method for producing a catalyst used in the alcohol production method, and use of the catalyst for producing alcohol.

[0012] The method for producing alcohol of the present invention has the steps described below. [Method for producing alcohol] The method for producing alcohol of this embodiment has the following steps 1 and 2. Step 1: A catalyst production step in which a cobalt-containing compound (a) and a copper-containing compound (b), both soluble in a protic solvent, are mixed in the protic solvent so that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol, and then reacted with a divalent or higher carboxylic acid compound (c), thereby obtaining a catalyst from the reaction product. Step 2: An alcohol production step in which a synthesis gas is reacted in the presence of the catalyst obtained in step 1 to obtain an alcohol.

[0013] According to the present invention, there is provided a method for producing alcohol from a synthesis gas, which can improve the alcohol selectivity and enable more selective production of alcohol.

[0014] In the present invention, "producing alcohol from synthesis gas" means producing alcohol from CO (carbon monoxide) and H ２ In the present invention, "producing alcohol by reacting synthesis gas" refers to the reaction of CO and H in the synthesis gas. ２ and reacting them to produce alcohol.

[0015] In the present invention, "soluble in a protic solvent" means that each component dissolves in the protic solvent described below at the temperature during preparation of the raw material solution, and from the viewpoint of catalyst production efficiency, the solubility is preferably 10 g / 100 g (protic solvent, 25°C) or more, more preferably 20 g / 100 g (protic solvent, 25°C) or more.

[0016] The alcohol production method of this embodiment will be described in detail below. <Step 1> Catalyst Production Step Step 1: In a protic solvent, a cobalt-containing compound (a) and a copper-containing compound (b) soluble in the protic solvent are mixed so that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol, and then reacted with a divalent or higher carboxylic acid compound (c), to obtain a catalyst from the reaction product. More specifically, in step 1, a cobalt-containing compound (a) and a copper-containing compound (b) soluble in the aprotic solvent are mixed in an aprotic solvent so that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol, and then coprecipitated with a precipitant containing a divalent or higher carboxylic acid compound (c), and then a catalyst is obtained from the coprecipitated reaction product. Examples of methods for obtaining a catalyst in this catalyst production step include the catalyst production methods described below.

[0017] [Protic Solvent] The protic solvent used here is a solvent that contains a proton (H ＋The protic solvent is a solvent capable of providing the cobalt-containing compound (a), the copper-containing compound (b), and the divalent or higher carboxylic acid compound (c) and capable of dissolving the precipitant containing the cobalt-containing compound (a), the copper-containing compound (b), and the divalent or higher carboxylic acid compound (c). On the other hand, the protic solvent is a solvent that does not dissolve but precipitates a reaction product obtained by reacting the precipitant containing the divalent or higher carboxylic acid compound (c) with the cobalt-containing compound (a) and the copper-containing compound (b).

[0018] The protic solvent is preferably a solvent that can efficiently proceed with the reaction and obtain a reactant having a uniform composition by coprecipitation. In terms of having good solubility for the raw material compounds and insolubilizing the reactant, the protic solvent has a relative dielectric constant at 20°C of preferably 3.0 or more, more preferably 10.0 or more, even more preferably 15.0 or more, and preferably 85.0 or less, more preferably 40.0 or less, even more preferably 35.0 or less, still more preferably 30.0 or less, and also preferably 3.0 or more and 85.0 or less, more preferably 3.0 or more and 40.0 or less, even more preferably 10.0 or more and 35.0 or less, and still more preferably 15.0 or more and 30.0 or less.

[0019] Examples of the protic solvent include water, alcohol, ether, and ketone, and more specifically, examples thereof include water (dielectric constant: 80.0, 20°C), alcohols such as ethanol (dielectric constant: 24.6, 20°C), isopropanol (dielectric constant: 18.3, 20°C), 1-propanol (dielectric constant: 20.2, 20°C), and 1-butanol (dielectric constant: 17.3, 20°C), ethers such as tetrahydrofuran (dielectric constant: 7.6, 20°C), and ketones such as acetone (dielectric constant: 21.5, 20°C). A mixed solvent of multiple solvents may be used as long as it has the above properties. From the above viewpoints, the protic solvent preferably contains one or more selected from the group consisting of water, alcohols, ethers, and ketones, more preferably one or more selected from the group consisting of ethanol, isopropanol, 1-propanol, 1-butanol, diethyl ether, tetrahydrofuran, and acetone, even more preferably one or more selected from the group consisting of ethanol and isopropanol, and even more preferably isopropanol.

[0020] [Cobalt-containing compound (a)] The cobalt-containing compound (a) is a compound containing cobalt, which serves as a catalytically active material, and which dissolves in a protic solvent and can be coprecipitated with the copper-containing compound (b) described below by reacting with a precipitant containing a divalent or higher carboxylic acid compound (c) in the protic solvent. Examples of the cobalt-containing compound (a) include cobalt salts, and from the viewpoint of improving catalytic performance, the cobalt-containing compound (a) preferably contains at least one selected from the group consisting of cobalt sulfate, cobalt chloride, cobalt bromide, cobalt iodide, cobalt acetate, and cobalt nitrate, and more preferably cobalt nitrate.

[0021] [Copper-containing compound (b)] The copper-containing compound (b) is a compound that contains copper and dissolves in a protic solvent, and can be coprecipitated with the cobalt-containing compound (a) by reaction with a precipitant containing a divalent or higher carboxylic acid compound (c) in the protic solvent. The copper-containing compound (b) is a copper salt, and from the viewpoint of improving catalytic performance, it preferably contains one or more selected from the group consisting of copper acetate, copper nitrate, copper sulfate, copper chloride, copper bromide, and copper iodide, more preferably one or more selected from the group consisting of copper acetate and copper nitrate, and even more preferably copper nitrate.

[0022] [Precipitant Containing Divalent or Higher Carboxylic Acid Compound (c)] This precipitant contains a divalent or higher carboxylic acid compound (c), i.e., a precipitant containing a compound having two or more carboxy groups per molecule. This precipitant containing a divalent or higher carboxylic acid compound (c) (hereinafter sometimes referred to as the "precipitant") is soluble in a protic solvent, and in the protic solvent, the carboxylic acid compound reacts with a cobalt-containing compound (a) and a copper-containing compound (b), resulting in coprecipitating the resulting reaction product (a cobalt-copper composite compound). This precipitant may contain a divalent or higher carboxylic acid compound. From the viewpoint of improving catalytic performance, the divalent or higher carboxylic acid compound preferably contains a carboxylic acid compound having 2 to 6 carbon atoms, more preferably one or more selected from the group consisting of oxalic acid, malonic acid, succinic acid, malic acid, and citric acid, even more preferably one or more selected from the group consisting of oxalic acid, malic acid, and citric acid, even more preferably one or more selected from the group consisting of oxalic acid and citric acid, and even more preferably oxalic acid. When the precipitant contains a divalent or higher carboxylic acid compound, the reactivity with the cobalt-containing compound (a) and the copper-containing compound (b) is improved, allowing for efficient formation of a precipitate. Note that, as the precipitant, a precipitant other than the divalent or higher carboxylic acid compound may also be contained within a range that does not inhibit the formation of the desired cobalt-copper composite compound. Examples of such precipitants include sodium carbonate, sodium bicarbonate, and ammonium carbonate.

[0023] [Catalyst Production Method] The method for obtaining a catalyst in step 1 (catalyst production step) is a method for obtaining a catalyst from a reactant (cobalt-copper composite compound) coprecipitated by a predetermined coprecipitation method using the raw material compounds (a cobalt-containing compound and a copper-containing compound soluble in a protic solvent) as described above. For example, the catalyst production method may include separating the coprecipitated reactant, drying it, and further treating the resulting dried product by a conventionally known treatment method for reduction and immobilization to obtain a catalyst. This catalyst production method is preferably a catalyst production method comprising the following steps 1-1 to 1-5. Step 1-1: A step of mixing a cobalt-containing compound (a) and a copper-containing compound (b) soluble in the protic solvent in the protic solvent so that the amount of copper per 1 mol of cobalt is 0.2 mol or more and 0.7 mol or less, and coprecipitating them with a precipitating agent containing a divalent or higher carboxylic acid compound (c); Step 1-2: A step of separating the reactant coprecipitated in Step 1-1 from the mixed solution after the reaction; Step 1-3: A step of drying the precipitate obtained by separation in Step 1-2; Step 1-4: A step of reducing the dried product obtained by drying in Step 1-3; and Step 1-5: A step of immobilizing the reduced product reduced in Step 1-4 to obtain a catalyst.

[0024] Specifically, a cobalt-copper composite catalyst can be obtained by sequentially performing steps 1-1 to 1-5 described below. <Step 1-1> First, a protic solvent, a cobalt-containing compound (a) soluble in the protic solvent, and a copper-containing compound (b) soluble in the protic solvent are prepared. Next, the prepared cobalt-containing compound (a) and copper-containing compound (b) are uniformly dissolved in the protic solvent and mixed so that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol, thereby obtaining a raw material solution. In addition, a precipitant containing a divalent or higher carboxylic acid compound (c) is prepared. The prepared precipitant may be used as is, or may be dissolved in the protic solvent and used as a precipitant solution.

[0025] Next, the raw material solution and a precipitant are mixed, and the cobalt-containing compound (a) and the copper-containing compound (b) are reacted with the precipitant to co-precipitate (deposit) a cobalt-copper composite compound, which is the reaction product. When the precipitant is used as is, the raw material solution and the precipitant are preferably mixed by adding the precipitant to the raw material solution. When a precipitant solution is used, the precipitant solution may be added to the raw material solution, or the raw material solution may be added to the precipitant solution. In other words, when a precipitant solution is used, Step 1 preferably includes the following Steps 1a, 1b, and 1c. Step 1a: A step of uniformly dissolving the cobalt-containing compound (a) and the copper-containing compound (b) in the protic solvent so that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol, thereby obtaining a raw material solution; Step 1b: A step of dissolving the precipitant in the protic solvent to obtain a precipitant solution; Step 1c: A step of mixing the raw material solution obtained in Step 1a and the precipitant solution obtained in Step 1b, thereby coprecipitating the cobalt-containing compound (a) and the copper-containing compound (b).

[0026] It is believed that the state of network formation in the cobalt-copper complex compound obtained varies depending on the combination of the protic solvent, cobalt-containing compound (a), copper-containing compound (b), and precipitant. Although the details are unknown, it is believed that the state of the network formed here affects the alcohol selectivity in Step 2, which will be described later.

[0027] <Step 1-2> Next, the reactant (cobalt-copper composite compound) coprecipitated (precipitated) in step 1-1 is separated from the post-reaction mixed solution. This separation can be carried out by a common separation procedure used in the field of catalyst production, and preferably involves one or more procedures selected from the group consisting of filtration, evaporation to dryness, and centrifugation. Examples of filtration include filter filtration and filtration with an aid. This separation procedure preferably involves one or more procedures selected from the group consisting of filtration and evaporation to dryness, more preferably one or more procedures selected from the group consisting of filter filtration and evaporation to dryness.

[0028] <Step 1-3> Next, the precipitate obtained by separation in Step 1-2 is dried by a drying treatment commonly used in the field of catalyst production, from the viewpoint of removing the protic solvent. The drying treatment includes one or more selected from the group consisting of air drying, hot air drying, heat drying, and reduced-pressure drying, preferably one or more selected from the group consisting of heat drying and reduced-pressure drying, and more preferably heat drying using a heater.

[0029] <Step 1-4> Furthermore, the dried product obtained by drying in step 1-3 is reduced to obtain a cobalt-copper composite catalyst. This reduction treatment can be performed by a conventional reduction treatment in the field of catalyst production. A hydrogen-containing gas may be used for the reduction treatment. The hydrogen-containing gas is preferably one or more hydrogen-containing gases selected from the group consisting of a mixed gas of carbon monoxide and hydrogen and a hydrogen-containing inert gas, more preferably a hydrogen-containing inert gas. Here, the reduction treatment reduces cobalt to metal. From the viewpoint of improving catalytic activity, the temperature of the reduction treatment (e.g., the temperature of the mixed gas of carbon monoxide and hydrogen or the hydrogen-containing inert gas) is preferably 150°C or higher, more preferably 200°C or higher, even more preferably 250°C or higher, and even more preferably 300°C or higher. From the same viewpoint, it is preferably 800°C or lower, more preferably 700°C or lower, even more preferably 600°C or lower, and even more preferably 500°C or lower. From the same viewpoint, the reduction temperature is preferably 150°C or higher and 800°C or lower, more preferably 200°C or higher and 700°C or lower, even more preferably 250°C or higher and 600°C or lower, and even more preferably 300°C or higher and 500°C or lower. From the viewpoint of improving catalytic activity, the reduction time of the reduction treatment is preferably more than 0 hours, more preferably 2 hours or higher, even more preferably 4 hours or higher, still more preferably 6 hours or higher, and even more preferably 8 hours or higher, and from the same viewpoint, it is preferably 24 hours or lower, more preferably 18 hours or lower, even more preferably 15 hours or lower, and even more preferably 12 hours or lower. From the same viewpoint, the reduction time is preferably more than 0 hours and 24 hours or lower, more preferably 2 hours or higher and 18 hours or lower, even more preferably 4 hours or higher and 15 hours or lower, still more preferably 6 hours or higher and 12 hours or lower, and even more preferably 8 hours or higher and 12 hours or lower. When the reduction treatment is carried out using the hydrogen-containing gas, the hydrogen concentration in the hydrogen-containing gas during the reduction treatment is, from the viewpoint of improving catalytic activity, preferably 1 vol% or more, more preferably 2 vol% or more, even more preferably 3 vol% or more, and still more preferably 4 vol% or more, and from the same viewpoint, preferably 100 vol% or less, more preferably 60 vol% or less, even more preferably 20 vol% or less, and still more preferably 10 vol% or less.

[0030] <Step 1-5> Then, the reduced product obtained in step 1-4 is passivated to improve catalytic activity. The passivation can be performed by a conventional passivation method used in the field of catalyst production. An oxygen-containing gas may be used for the passivation, and an oxygen-containing inert gas is preferred as the oxygen-containing gas. Here, cobalt is stabilized by the passivation. The passivation temperature (e.g., the temperature of the oxygen-containing inert gas) is preferably 100°C or less, more preferably 70°C or less, even more preferably 50°C or less, and even more preferably 40°C or less, from the viewpoint of catalyst stabilization through oxide film formation. From the same viewpoint, the passivation temperature is preferably 0°C or more, more preferably 10°C or more, even more preferably 20°C or more, and even more preferably 25°C or more. From the same viewpoint, the temperature is preferably 0°C or more and 100°C or less, more preferably 10°C or more and 70°C or less, even more preferably 20°C or more and 50°C or less, and even more preferably 25°C or more. The passivation treatment time is preferably 30 minutes or more, more preferably 1 hour or more, even more preferably 2 hours or more, and even more preferably 3 hours or more, from the viewpoint of catalyst stabilization through oxide film formation. From the same viewpoint, it is preferably 10 hours or less, more preferably 8 hours or less, even more preferably 6 hours or less, and even more preferably 4 hours or less. From the same viewpoint, it is preferably 30 minutes to 10 hours, more preferably 1 hour to 8 hours, even more preferably 2 hours to 6 hours, and even more preferably 3 hours to 4 hours. From the viewpoint of catalyst stabilization through oxide film formation, the oxygen concentration in the oxygen-containing gas during the passivation treatment is preferably 0.1 vol% or more, more preferably 0.5 vol% or more, even more preferably 0.8 vol% or more, and even more preferably 1.0 vol% or more. From the same viewpoint, it is preferably 10 vol% or less, more preferably 6.0 vol% or less, even more preferably 2.0 vol% or less, and even more preferably 1.5 vol% or less.

[0031] In this case, from the viewpoint of improving catalytic performance, the amounts of the cobalt-containing compound (a) and the copper-containing compound (b) used in the protic solvent are such that the amount of copper in the copper-containing compound (b) per 1 mol of cobalt in the cobalt-containing compound (a) is preferably 0.2 mol or more, more preferably 0.35 mol or more, even more preferably 0.50 mol or more, and preferably 0.70 mol or less, more preferably 0.65 mol or less, even more preferably 0.60 mol or less, and also preferably 0.2 mol or more and 0.7 mol or less, more preferably 0.35 mol or more and 0.65 mol or less, even more preferably 0.50 mol or more and 0.60 mol or less. The amounts of cobalt and copper used in this catalyst production method are maintained as equivalent amounts in the resulting cobalt-copper composite catalyst.

[0032] When coprecipitating in a protic solvent, as described above, by setting the amount (mol) of copper per mol of cobalt within a predetermined range, the catalyst structure can be further stabilized, and the alcohol selectivity in the alcohol production in Step 2 described below can be improved.

[0033] The amount of the precipitant blended in the protic solvent is such that the molar ratio (precipitant / (cobalt content+copper content)) to the total content of the cobalt content in the cobalt-containing compound (a) and the copper content in the copper-containing compound (b) is preferably 0.9 or more, more preferably 0.95 or more, and is preferably 1.5 or less, more preferably 1.2 or less, and also preferably 0.9 or more and 1.5 or less, more preferably 0.95 or more and 1.2 or less.

[0034] Furthermore, the temperature of the protic solvent and / or the mixture during co-precipitation in the protic solvent is preferably 5°C or higher, more preferably 15°C or higher, even more preferably 20°C or higher, and is preferably 50°C or lower, more preferably 40°C or lower, even more preferably 30°C or lower, from the viewpoint of stability of the reactant (precipitate) and prevention of solvent evaporation, and is also preferably 5°C or higher and 50°C or lower, more preferably 15°C or higher and 40°C or lower, even more preferably 20°C or higher and 30°C or lower.

[0035] <Step 2> Alcohol Production Step In this step 2, carbon monoxide (CO) and hydrogen (H ２ In step 2, alcohol is obtained from synthesis gas containing CO and H in the presence of a cobalt-copper composite catalyst. ２ This method involves reacting a synthesis gas (feedstock gas) containing the above-mentioned cobalt-copper composite catalyst to produce alcohol. For example, alcohol can be produced by placing a solvent and a cobalt-copper composite catalyst in a reaction vessel and passing the synthesis gas through the reaction vessel. Since the catalyst and the synthesis gas exist in different phases, it is desirable to promote mass transfer between the phases by, for example, bubbling the gas into the liquid. By using the cobalt-copper composite catalyst obtained by the above-mentioned method, this embodiment can improve the alcohol selectivity in the reaction mixture compared to conventionally known methods.

[0036] The synthesis gas used in step 2 is CO and H ２ The synthesis gas can be obtained by a conventional method, for example, steam reforming of hydrocarbons such as natural gas and liquefied petroleum gas, or partial oxidation of fuels or biomass. ２ From the viewpoint of improving productivity, the composition of ２ Molar ratio (H ２ / CO) is preferably 1.0 or more, more preferably 1.3 or more, even more preferably 1.8 or more, and is preferably 2.5 or less, more preferably 2.4 or less, even more preferably 2.2 or less, and is preferably 1.0 or more and 2.5 or less, more preferably 1.3 or more and 2.4 or less, even more preferably 1.8 or more and 2.2 or less.

[0037] A gas phase is present in the reaction system when producing alcohol in step 2, and it is preferable to carry out the reaction under a synthesis gas atmosphere in order to maintain the activity of the catalyst. The reaction pressure (gauge pressure) of this gas phase is preferably 3.0 MPa or more, more preferably 4.0 MPa or more, even more preferably 5.0 MPa or more, and even more preferably 5.5 MPa or more from the viewpoint of improving catalyst performance, and is preferably 50 MPa or less, more preferably 30 MPa or less, even more preferably 10 MPa or less, and even more preferably 7.0 MPa or less from the viewpoint of reducing the burden on the equipment. Also, it is preferably 3.0 MPa or more and 50 MPa or less, more preferably 4.0 MPa or more and 40 MPa or less, even more preferably 5.0 MPa or more and 30 MPa or less, and even more preferably 5.5 MPa or more and 7.0 MPa or less.

[0038] The temperature of the solvent in step 2 (reaction temperature) is preferably 100°C or higher, more preferably 150°C or higher, even more preferably 200°C or higher, and still more preferably 230°C or higher, from the viewpoint of improving catalytic activity, and is preferably 300°C or lower, more preferably 270°C or lower, and even more preferably 250°C or lower, from the viewpoint of improving energy efficiency, and is also preferably 100°C or higher and 300°C or lower, more preferably 150°C or higher and 300°C or lower, even more preferably 200°C or higher and 270°C or lower, and still more preferably 230°C or higher and 250°C or lower.

[0039] The reactor in which the reaction of step 2 is carried out is preferably an reactor selected from the group consisting of a slurry bed reactor and a fixed bed reactor, more preferably a slurry bed reactor. In particular, from the viewpoints of catalyst durability (suppression of catalyst pore clogging) and stable production (high reaction heat removal efficiency), it is preferable to use a slurry bed reactor using a slurry bed (liquid-phase reaction). Note that the stable production refers to a state in which consistent quality and production volume can be maintained continuously under certain reaction conditions.

[0040] In the alcohol production method of this embodiment, as described above, CO and H ２In a method for producing alcohol from a synthesis gas containing CO, the alcohol selectivity can be improved, and alcohol can be obtained more selectively. The alcohol obtained in this case is, for example, a straight-chain alcohol having about 1 to 20 carbon atoms, although it is affected by the reaction conditions, etc. The alcohol obtained in this manner can be used as various alcohols, and can also be used as a raw material for various organic compounds. Among them, alcohols having 2 or more carbon atoms can be used as organic solvents, disinfectants, cleaning agents, fuels, etc. The catalyst produced by the catalyst production method of this embodiment is obtained in a step corresponding to step 1 of the alcohol production method, and is a catalyst obtained by reacting CO and H ２ The present invention has the effect of improving the alcohol selectivity in a method for producing alcohol from a synthesis gas containing the above-mentioned compound, and is therefore useful as a catalyst in the method for producing alcohol.

[0041] [Use for Producing Alcohol] The use for producing alcohol of the present embodiment involves mixing a cobalt-containing compound (a) and a copper-containing compound (b), which are soluble in a protic solvent, in the protic solvent so that the amount of copper per 1 mol of cobalt is 0.2 mol or more and 0.7 mol or less, and reacting the mixture with a divalent or higher carboxylic acid compound (c), and then using the catalyst obtained from the reaction product to react carbon monoxide and hydrogen in a synthesis gas to produce alcohol.

[0042] In addition to the above-described embodiments, the present invention discloses the following: <1> A method for producing an alcohol, comprising the following steps 1 and 2: Step 1: A catalyst production step in which a cobalt-containing compound (a) and a copper-containing compound (b), both soluble in a protic solvent, are mixed in the protic solvent such that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol, and the mixture is coprecipitated with a precipitant containing a divalent or higher carboxylic acid compound (c), and a catalyst is obtained from the coprecipitated reaction product; and Step 2: An alcohol production step in which a synthesis gas is reacted in the presence of the catalyst obtained in Step 1 to obtain an alcohol. <2> The alcohol production method according to <1>, wherein the protic solvent has a relative dielectric constant at 20°C of 3.0 to 85.0, preferably 3.0 to 40.0, more preferably 10.0 to 35.0, and even more preferably 15.0 to 30.0. <3> The method for producing an alcohol according to <1> or <2>, wherein the protic solvent is at least one selected from the group consisting of water, an alcohol, an ether, and a ketone, preferably at least one selected from the group consisting of water, ethanol, isopropanol, 1-propanol, 1-butanol, diethyl ether, tetrahydrofuran, and acetone, more preferably at least one selected from the group consisting of water, ethanol, and isopropanol, and even more preferably at least one selected from the group consisting of water, ethanol, and isopropanol.<4> The method for producing an alcohol according to any one of <1> to <3>, wherein the cobalt-containing compound (a) is a cobalt salt, preferably at least one selected from the group consisting of cobalt sulfate, cobalt chloride, cobalt bromide, cobalt iodide, cobalt acetate, and cobalt nitrate, more preferably cobalt nitrate. <5> The method for producing an alcohol according to any one of <1> to <4>, wherein the copper-containing compound (b) is a copper salt, and is preferably at least one selected from the group consisting of copper acetate, copper nitrate, copper sulfate, copper chloride, copper bromide, and copper iodide, more preferably at least one selected from the group consisting of copper acetate and copper nitrate, and even more preferably copper nitrate.<6> The method for producing an alcohol according to any one of <1> to <5>, wherein the precipitating agent is a carboxylic acid compound having 2 to 6 carbon atoms, and is preferably at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, malic acid, and citric acid, more preferably at least one selected from the group consisting of oxalic acid, malic acid, and citric acid, even more preferably at least one selected from the group consisting of oxalic acid and citric acid, still more preferably at least one selected from the group consisting of oxalic acid and citric acid, even more preferably at least one selected from the group consisting of oxalic acid and citric acid, and still more preferably oxalic acid. <7> The method for producing an alcohol according to any one of <1> to <6>, wherein the cobalt-containing compound (a) is a cobalt salt selected from the group consisting of cobalt acetate and cobalt nitrate, the copper-containing compound (b) is one or more selected from the group consisting of copper acetate, copper nitrate, copper sulfate, copper chloride, copper bromide, and copper iodide, the precipitating agent is one or more selected from the group consisting of oxalic acid, malic acid, and citric acid, and the protic solvent is one or more selected from the group consisting of ethanol and isopropanol. <8> The method for producing an alcohol according to any one of <1> to <7>, wherein the cobalt-containing compound (a) is cobalt nitrate, the copper-containing compound (b) is one or more selected from the group consisting of copper acetate and copper nitrate, the precipitating agent is oxalic acid, and the protic solvent is isopropanol. <9> The method for producing an alcohol according to any one of <1> to <8>, wherein the cobalt-containing compound (a) is cobalt nitrate, the copper-containing compound (b) is copper nitrate, the precipitating agent is oxalic acid, and the protic solvent is isopropanol. <10> The molar ratio of hydrogen to carbon monoxide in the synthesis gas (H. ２<1> The method for producing an alcohol according to any one of <1> to <9>, wherein the β-CO ratio (CO / CO) is preferably 1.0 or more, more preferably 1.3 or more, even more preferably 1.8 or more, and preferably 2.5 or less, more preferably 2.4 or less, even more preferably 2.2 or less, and is preferably 1.0 or more and 2.5 or less, more preferably 1.3 or more and 2.4 or less, even more preferably 1.8 or more and 2.2 or less. <11> The method for producing an alcohol according to any one of <1> to <10>, wherein the step 1 includes the following steps 1a, 1b, and 1c: <12> The method for producing an alcohol according to any one of <1> to <11>, further comprising the steps of: Step 1a: uniformly dissolving the cobalt-containing compound (a) and the copper-containing compound (b) in the protic solvent so that the amount of copper per 1 mol of cobalt is 0.2 mol or more and 0.7 mol or less, to obtain a raw material solution; Step 1b: dissolving the precipitant in the protic solvent to obtain a precipitant solution; and Step 1c: mixing the raw material solution obtained in Step 1a with the precipitant solution obtained in Step 1b, to co-precipitate the cobalt-containing compound (a) and the copper-containing compound (b). <12> The method for producing an alcohol according to any one of <1> to <11>, further comprising the steps of separating and drying the co-precipitated reaction product from the mixed solution after the reaction in Step 1. <13> The method for producing an alcohol according to any one of <1> to <12>, wherein in step 1, the coprecipitated reaction product is separated from the mixed solution after the reaction and dried, and the drying is carried out by one or more methods selected from the group consisting of air drying, hot air drying, heat drying, and reduced-pressure drying, preferably by one or more methods selected from the group consisting of heat drying and reduced-pressure drying, and more preferably by heat drying using a heater. <14> The method for producing an alcohol according to any one of <1> to <13>, wherein in step 1, the coprecipitated reaction product is separated from the mixed solution after the reaction and dried, and further, the obtained dried product is subjected to a reduction treatment and a passivation treatment. <15> The method for producing an alcohol according to any one of <1> to <14>, wherein in step 1, the catalyst is obtained by reducing the coprecipitated reaction product, and the reduction treatment is carried out with a hydrogen-containing gas, preferably one or more hydrogen-containing gases selected from the group consisting of a mixed gas of carbon monoxide and hydrogen and a hydrogen-containing inert gas.<16> The method for producing an alcohol according to any one of <1> to <15>, wherein in step 1, the catalyst is obtained by reducing the coprecipitated reaction product, and the temperature of the reduction treatment is preferably 150°C or higher, more preferably 200°C or higher, even more preferably 250°C or higher, still more preferably 300°C or higher, and preferably 800°C or lower, more preferably 700°C or lower, even more preferably 600°C or lower, and still more preferably 500°C or lower; and from the same viewpoint, preferably 150°C or higher and 800°C or lower, more preferably 200°C or higher and 700°C or lower, even more preferably 250°C or higher and 600°C or lower, and still more preferably 300°C or higher and 500°C or lower. <17> The method for producing an alcohol according to any one of <1> to <16>, wherein in step 1, the catalyst is obtained by subjecting the coprecipitated reactant to a reduction treatment, and the time for the reduction treatment is preferably longer than 0 hours, more preferably 2 hours or more, even more preferably 4 hours or more, still more preferably 6 hours or more, still more preferably 8 hours or more, and preferably 24 hours or less, more preferably 18 hours or less, even more preferably 15 hours or less, and still more preferably 12 hours or less; and from the same viewpoint, preferably longer than 0 hours and 24 hours or less, more preferably 2 hours or more and 18 hours or less, even more preferably 4 hours or more and 15 hours or less, still more preferably 6 hours or more and 12 hours or less, and still more preferably 8 hours or more and 12 hours or less. <18> The method for producing an alcohol according to any one of <1> to <17>, wherein in step 1, the catalyst is obtained by reducing the coprecipitated reactant, the reduction is preferably carried out with one or more hydrogen-containing gases selected from the group consisting of a mixed gas of carbon monoxide and hydrogen and a hydrogen-gas-containing inert gas, and the hydrogen concentration in the hydrogen-containing gas during the reduction is preferably 1 vol% or more, more preferably 2 vol% or more, even more preferably 3 vol% or more, still more preferably 4 vol% or more, and preferably 100 vol% or less, more preferably 60 vol% or less, even more preferably 20 vol% or less, and still more preferably 10 vol% or less.<19> The method for producing an alcohol according to any one of <1> to <18>, wherein in step 1, the catalyst is obtained by subjecting the coprecipitated reactant to a reduction treatment and then to a passivation treatment, and the passivation treatment is carried out with an oxygen-containing gas, preferably an oxygen-containing inert gas. <20> The method for producing an alcohol according to any one of <1> to <19>, wherein in step 1, the catalyst is obtained by subjecting the coprecipitated reactant to a reduction treatment and then to a passivation treatment, and the passivation treatment is carried out at a temperature of preferably 100°C or lower, more preferably 70°C or lower, even more preferably 50°C or lower, still more preferably 40°C or lower, and preferably 0°C or higher, more preferably 10°C or higher, even more preferably 20°C or higher, still more preferably 25°C or higher, and also preferably 0°C or higher and 100°C or lower, more preferably 10°C or higher and 70°C or lower, even more preferably 20°C or higher and 50°C or lower, and still more preferably 25°C or higher and 40°C or lower. <21> The method for producing an alcohol according to any one of <1> to <20>, wherein in step 1, the catalyst is obtained by subjecting the coprecipitated reactant to a reduction treatment and then to a passivation treatment, and the time for the passivation treatment is preferably 30 minutes or more, more preferably 1 hour or more, even more preferably 2 hours or more, still more preferably 3 hours or more, and preferably 10 hours or less, more preferably 8 hours or less, even more preferably 6 hours or less, still more preferably 4 hours or less, and also preferably 30 minutes to 10 hours, more preferably 1 hour to 8 hours, even more preferably 2 hours to 6 hours, still more preferably 3 hours to 4 hours. <22> The method for producing an alcohol according to any one of <1> to <21>, wherein in step 1, the catalyst is obtained by subjecting the coprecipitated reactant to a reduction treatment and then to a passivation treatment, the passivation treatment is carried out with an oxygen-containing gas, and the oxygen concentration in the oxygen-containing gas during the passivation treatment is preferably 0.1 vol% or more, more preferably 0.5 vol% or more, even more preferably 0.8 vol% or more, still more preferably 1.0 vol% or more, and preferably 10 vol% or less, more preferably 6.0 vol% or less, even more preferably 2.0 vol% or less, and still more preferably 1.5 vol% or less.<23> The method for producing an alcohol according to any one of <1> to <22>, wherein the step 1 is a catalyst production step of mixing, in a protic solvent, a cobalt-containing compound (a) and a copper-containing compound (b), both soluble in the protic solvent, in an amount such that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol, and coprecipitating the mixture with a precipitating agent containing a divalent or higher carboxylic acid compound (c), and then obtaining a catalyst from the coprecipitated reaction product. <24> The method for producing an alcohol according to any one of <1> to <23>, wherein the reaction in the step 2 is carried out in a reactor selected from the group consisting of a slurry bed reactor and a fixed bed reactor, preferably a slurry bed reactor. <25> The method for producing an alcohol according to any one of <1> to <24>, wherein in step 2, a gas phase is present in the reaction system when producing an alcohol, and the reaction is carried out under an inert gas atmosphere, and the reaction pressure (gauge pressure) of the gas phase is preferably 3.0 MPa or more, more preferably 4.0 MPa or more, even more preferably 5.0 MPa or more, still more preferably 5.5 MPa or more, and preferably 50 MPa or less, more preferably 30 MPa or less, even more preferably 10 MPa or less, still more preferably 7.0 MPa or less, and also preferably 3.0 MPa or more and 50 MPa or less, more preferably 4.0 MPa or more and 40 MPa or less, even more preferably 5.0 MPa or more and 30 MPa or less, still more preferably 5.5 MPa or more and 7.0 MPa or less. <26> The method for producing an alcohol according to any one of <1> to <25>, wherein the reaction temperature in Step 2 is preferably 100°C or higher, more preferably 150°C or higher, even more preferably 200°C or higher, still more preferably 230°C or higher, and preferably 300°C or lower, more preferably 270°C or lower, even more preferably 250°C or lower, or 100°C or higher and 300°C or lower, preferably 150°C or higher and 300°C or lower, more preferably 200°C or higher and 270°C or lower, even more preferably 230°C or higher and 250°C or lower. <27> The method for producing an alcohol according to any one of <1> to <26>, wherein in Step 2, a gas phase is present in the reaction system when producing the alcohol, the reaction pressure (gauge pressure) of the gas phase is 3.0 MPa or higher and 50 MPa or lower, and the reaction temperature is 100°C or higher and 300°C or lower.<28> The method for producing an alcohol according to any one of <1> to <27>, wherein in step 2, a gas phase is present in the reaction system when the alcohol is produced, the reaction pressure (gauge pressure) of the gas phase is 3.0 MPa or more and 50 MPa or less, and the reaction temperature is 150°C or more and 300°C or less. <29> The method for producing an alcohol according to any one of <1> to <28>, wherein in step 2, a gas phase is present in the reaction system when the alcohol is produced, the synthesis gas is reacted under a synthesis gas atmosphere, the reaction pressure (gauge pressure) of the gas phase is 4.0 MPa or more and 40 MPa or less, and the reaction temperature is 200°C or more and 270°C or less. <30> The method for producing an alcohol according to any one of <1> to <29>, wherein in step 2, a gas phase is present in the reaction system when the alcohol is produced, the synthesis gas is reacted under a synthesis gas atmosphere, the reaction pressure (gauge pressure) of the gas phase is 5.0 MPa or more and 30 MPa or less, and the reaction temperature is 230°C or more and 250°C or less. <31> The method for producing an alcohol according to any one of <1> to <30>, wherein in step 2, a gas phase is present in the reaction system when producing the alcohol, the synthesis gas is reacted under a synthesis gas atmosphere, the reaction pressure (gauge pressure) of the gas phase is 5.5 to 7.0 MPa, and the reaction temperature is 230 to 250° C. <32> A method for producing an alcohol, comprising mixing a cobalt-containing compound (a) and a copper-containing compound (b) that are soluble in a protic solvent in an amount of 0.2 mol to 0.7 mol of copper per 1 mol of cobalt, reacting the mixture with a divalent or higher carboxylic acid compound (c), and obtaining a catalyst from the reaction product. <33> A method for producing a catalyst, comprising the following step 1: <34> The method for producing a catalyst according to <33>, further comprising a step of separating the coprecipitated reaction product from the mixed solution after the reaction in step 1. <35> The method for producing a catalyst according to <34>, further comprising a step of drying the separated precipitate in step 1.<36> The method for producing a catalyst according to <35>, further comprising a step of reducing the dried product obtained by drying in step 1. <37> The method for producing a catalyst according to <36>, further comprising a step of immobilizing the reduced product obtained by reduction. <38> The method for producing a catalyst, comprising the following steps 1-1 to 1-5: Step 1-1: a step of mixing, in a protic solvent, a cobalt-containing compound (a) and a copper-containing compound (b), both soluble in the protic solvent, such that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol, and coprecipitating them with a precipitating agent containing a divalent or higher carboxylic acid compound (c); Step 1-2: a step of separating the reactant coprecipitated in Step 1-1 from the mixed solution after the reaction; Step 1-3: a step of drying the precipitate obtained by separation in Step 1-2; Step 1-4: a step of reducing the dried product obtained by drying in Step 1-3; and Step 1-5: a step of immobilizing the product reduced in Step 1-4 to obtain a catalyst. <39> A method for producing an alcohol, comprising reacting a synthesis gas in the presence of a catalyst obtained by the method for producing a catalyst according to any one of <32> to <38>. <40> A method for producing an alcohol by reacting a cobalt-containing compound (a) and a copper-containing compound (b), both soluble in a protic solvent, with a divalent or higher carboxylic acid compound (c) in a protic solvent in an amount of 0.2 mol or more and 0.7 mol or less of copper per 1 mol of cobalt, and using a catalyst obtained from the reaction product to react carbon monoxide and hydrogen in a synthesis gas.

[0043] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. Measurements and evaluations in the examples were carried out by the methods described below. Unless otherwise specified, the samples were prepared at room temperature (25°C) and atmospheric pressure.

[0044] Example 1: Co-Cu Catalyst a) A 0.5 L vessel was charged with a stirrer tip (size 4.0 cm), and 5.18 g (17.8 mmol) of cobalt(II) nitrate hexahydrate (Kanto Chemical Co., Inc.), 1.71 g (7.08 mmol) of copper(II) nitrate trihydrate (Kanto Chemical Co., Inc.), and 120 mL of ethanol were added and stirred at 600 rpm for 30 minutes to prepare Mixed Solution 1 (raw material solution: Cu / Co molar ratio 0.40). A 0.5 L vessel was charged with a stirrer tip (size 4.0 cm), and 2.24 g (24.9 mmol) of oxalic acid and 230 mL of ethanol were added and stirred at 600 rpm for 30 minutes to prepare a precipitant solution. After stirring, Mixed Solution 1 (120 mL) was added dropwise to the precipitant solution over 30 minutes. After the dropwise addition, the mixture was stirred at 600 rpm for 30 minutes. After stirring, the precipitate was filtered (using a 0.2 μm pore size membrane filter (manufactured by ADVANTEC)). The filtered material was dried at 120 ° C for 16 hours under an air atmosphere. The dried catalyst was placed in a reduction furnace (muffle furnace) for 30 minutes and cooled to room temperature (25 ° C). The air in the muffle furnace was replaced with nitrogen, and nitrogen containing 4 vol% hydrogen was passed through the muffle furnace at atmospheric pressure at 40 mL per minute. The temperature was raised from room temperature (25 ° C) to 400 ° C over 3 hours, and the mixture was maintained at 400 ° C for 10 hours to carry out reduction. After completion of reduction, the nitrogen flow rate was changed to 40 mL per minute, and the mixture was cooled to room temperature (25 ° C). Then, nitrogen containing 1 vol% oxygen was passed through the muffle furnace at 15 mL per minute for 240 minutes, and surface passivation treatment was performed to obtain Co-Cu catalyst a.

[0045] Next, a semi-batch autoclave (C-401, manufactured by Toyo Koatsu Co., Ltd.) with an internal volume of 100 mL was used as the reactor for producing alcohol from synthesis gas. 40 mL of n-hexadecane (manufactured by Kanto Chemical Co., Ltd.) and 0.5 g of a catalyst with an average particle size of 1 μm were placed in the reactor, and the inside of the piping was replaced with nitrogen. Then, synthesis gas (H ２A mixture of 1000kJ / CO (molar ratio) = 2.0, hydrogen content = 65 vol%, carbon monoxide content = 32 vol%, and argon content = 3 vol%) was supplied and aerated at 10 L / min, and the gauge pressure was increased to 6.0 MPa. After the pressure was increased, the temperature was increased from room temperature (25°C) to 240°C over 1 hour and 30 minutes. The reaction started when the temperature reached 240°C. The contents in the reactor were stirred at 1200 rpm, and the reaction was carried out for 3 hours, yielding a reaction product containing alcohol.

[0046] (Examples 2 to 4: Co-Cu catalysts b to d) Co-Cu catalyst b (Example 2), Co-Cu catalyst c (Example 3), and Co-Cu catalyst d (Example 4) were obtained in the same manner as in Example 1, except that the compounds and amounts used were as shown in Table 1. Furthermore, the obtained Co-Cu catalysts b to d were subjected to the same operation as in Example 1 to obtain a reaction product containing alcohol from the synthesis gas.

[0047] (Example 5: Co—Cu Catalyst e) A stirrer tip (size: 4.0 cm) was placed in a 1.0 L container, and 350 mL of cobalt(II) nitrate hexahydrate (Kanto Chemical), copper(II) nitrate trihydrate (Kanto Chemical), and isopropanol were added. The mixture was stirred at 600 rpm for 30 minutes to prepare a mixed solution (raw material solution). Citric acid (Kanto Chemical) was added to this mixed solution in the amount shown in Table 1, and the mixture was stirred at 600 rpm for 30 minutes. The stirrer tip was then removed from the container, and the solvent was removed at 10 Torr and 40°C using an evaporator (BUCHI Catalog No. U00210), and the precipitate was recovered. The precipitate was dried in an air atmosphere at 120°C for 16 hours. The dried catalyst was placed in a reduction furnace (muffle furnace) for 30 minutes and then cooled to room temperature (25°C). The air in the muffle furnace was replaced with nitrogen, and nitrogen containing 4% by volume of hydrogen was passed through the muffle furnace at atmospheric pressure at 40 mL per minute. The temperature was raised from room temperature (25 ° C) to 400 ° C over 3 hours, and the furnace was held at 400 ° C for 10 hours to carry out reduction. After completion of reduction, the nitrogen was switched to 40 mL per minute, and the furnace was cooled to room temperature (25 ° C). Then, nitrogen containing 1% by volume of oxygen was passed through the muffle furnace at 15 mL per minute for 240 minutes, and surface passivation treatment was performed to obtain Co-Cu catalyst e (Example 5). Furthermore, the obtained Co-Cu catalyst e was operated in the same manner as in Example 1, and a reaction product containing alcohol was obtained from the synthesis gas.

[0048] (Example 6: Co-Cu catalyst f) Co-Cu catalyst f (Example 6) was obtained in the same manner as in Example 1, except that the compounds and amounts used were as shown in Table 1. Furthermore, the obtained Co-Cu catalyst f was subjected to the same operation as in Example 1 to obtain a reaction product containing alcohol from a synthesis gas.

[0049] (Comparative Example 1: Co Catalyst) A Co catalyst was obtained by the same procedure as in Example 1, except that the compounds and amounts used were as shown in Table 1. Furthermore, the obtained Co catalyst was subjected to the same procedure as in Example 1 to obtain a reaction product containing alcohol from a synthesis gas. (Comparative Examples 2 to 4: Co-Cu Catalysts C1 to C3) A Co-Cu catalyst C1 (Comparative Example 2), a Co-Cu catalyst C2 (Comparative Example 3), and a Co-Cu catalyst C3 (Comparative Example 4) were obtained by the same procedure as in Example 1, except that the compounds and amounts used were as shown in Table 1. Furthermore, the obtained Co-Cu catalysts C1 to C3 were subjected to the same procedure as in Example 1 to obtain a reaction product containing alcohol from a synthesis gas.

[0050] The catalyst, synthesis gas, and reaction products obtained as described above were analyzed for composition and components, and the CO conversion and selectivity for each compound were calculated. The results are summarized in Table 1.

[0051] [Method for Analyzing Gas Components During the Reaction] The gas components during the reaction were introduced every hour through the piping at the outlet of the reaction apparatus into a gas chromatograph (also referred to as GC) equipped with a thermal conductivity detector (also referred to as TCD) or a flame ionization detector (also referred to as FID), and GC analysis was performed using argon as an internal standard substance.

[0052] The volume concentration of carbon monoxide in the gaseous components was calculated by the internal standard method using argon as the internal standard from the GC peak area percentages attributable to carbon monoxide and argon. A calibration curve was prepared by measuring a gas mixture of standard gases consisting of carbon monoxide, methane, and carbon dioxide, and argon, and plotting the peak area ratios of carbon monoxide and argon against the volume concentration ratio of carbon monoxide and argon at each mixture ratio.

[0053] The volume concentration of methane in the gas components was calculated from the GC peak area percentages of methane and argon by the internal standard method using argon as the internal standard. A calibration curve was created by measuring a standard gas consisting of carbon monoxide, methane, and carbon dioxide, and a gas mixture containing argon, and plotting the peak area ratios of carbon monoxide and argon against the volume concentration ratio of methane and argon at each mixture ratio.

[0054] The volume concentration of olefins in the gaseous components was calculated by the following formula: Volume concentration % of olefins = Volume concentration % of methane × (GC peak area derived from all detected olefins of different carbon numbers / GC peak area derived from detected methane).

[0055] The volume concentration of paraffin in the gaseous components was calculated by the following formula: Volume concentration of paraffin % = Volume concentration of methane % × (GC peak area derived from paraffins of all detected carbon numbers / GC peak area derived from detected methane).

[0056] <GC measurement conditions> - For CO and methane Sample amount: 1 mL Gas chromatography: GC-320 (GL Sciences) Detector: TCD (built into gas chromatograph) Column: Active Carbon (GL Sciences, 60-80 mesh, column length 3 m, inner diameter 2 mm) Temperature condition: 80°C constant Carrier gas: H ２ , inlet pressure 200 kPa Sample introduction part temperature: 110°C, detector temperature: 80°C - For olefins and paraffins Sample introduction amount: 0.8 mL Gas chromatography: GC-14B (Shimadzu Corporation) Detector: FID (built into gas chromatograph) Column: Porapak Q (GL Sciences, packing mesh size 80 / 100, column length 3 m, inner diameter 2 mm) Temperature conditions: 70°C → 230°C (heating rate 2°C / min) Carrier gas: N ２ , inlet pressure 200 kPa, sample introduction part temperature: 200°C, detector temperature: 230°C

[0057] [Analysis of Liquid Components of Reaction Product at Reaction Completion] After the reaction was completed and cooled to room temperature, the reactor and ice trap were removed. The products in the ice trap were mixed in the reactor, and deionized water was added to the mixture to separate the organic and aqueous layers. As internal standards, 0.1 g of 1-octanol (Kanto Chemical Co., Inc.) and 0.1 g of dodecane (Kanto Chemical Co., Inc.) were added to the organic layer, and 0.05 g of tert-butanol (Kanto Chemical Co., Inc.) was added to the aqueous layer. After thorough stirring, the resulting solution was subjected to GC analysis. 0.2 μL of each sample was directly introduced into the GC for GC analysis. The alcohol concentration in the organic layer was calculated using a conversion formula based on the area percentage of the detected GC peaks derived from each alcohol and the area percentage of the GC peak derived from dodecane. The conversion formula was determined from the peak areas of each alcohol of known concentration and 1-octanol of known concentration. The concentrations of olefins and paraffins in the organic layer were calculated using a conversion formula from the area % of the detected GC peaks derived from each olefin and paraffin and the area % of the GC peak derived from dodecane. The conversion formula was determined from the peak areas of each olefin, paraffin, and dodecane of known concentrations. The alcohol concentration in the aqueous layer was calculated using a conversion formula from the area % of the detected GC peak derived from each alcohol and the area % of the GC peak derived from tert-butanol. The conversion formula was determined from the peak areas of each alcohol concentration of known concentration and tert-butanol of known concentration. GC measurement conditions Sample introduction amount: 0.2 μL Gas chromatography: GC-2014 (Shimadzu Corporation)

[0058] [Methods for calculating CO conversion, alcohol selectivity, and alcohol selectivity having two or more carbon atoms] The CO conversion, alcohol selectivity, and alcohol selectivity having two or more carbon atoms (C ２＋The conversion rate, alcohol selectivity, and alcohol selectivity were calculated according to the following formula. In the formula below, C-mol% (carbon mole %) is the ratio of the number of moles of carbon atoms in each product to the number of moles of carbon atoms in all products, and is expressed by the following formula: C-mol% (carbon mole %) = (number of moles of carbon atoms in each product / number of moles of carbon atoms in all products) × 100. The total amount of HC produced represents the total amount of hydrocarbons produced, and is calculated by the following formula: Total amount of HC produced (C-mol%) = total amount of olefins produced (C-mol%) + total amount of paraffins produced (C-mol%). The higher the CO conversion, alcohol selectivity, and selectivity to alcohols having two or more carbon atoms, the better the catalyst performance in light of the object of the present invention.

[0059] Calculation formula for reactants CO conversion rate (%) = (1 - (CO concentration (mol%) in gas components at reactor outlet / CO concentration (mol%) in gas supplied to reactor)) × 100 Alcohol selectivity (%; C-mol ratio) = (total amount of ROH produced (C-mol%) / (total amount of ROH produced (C-mol%) + total amount of HC produced (C-mol%))) × 100 C ２＋ Alcohol selectivity (%; C-molar ratio) = (C ２＋ Total amount of ROH produced (C-mol%) / (Total amount of ROH produced (C-mol%)+Total amount of HC produced (C-mol%))×100 Here, the total amount of ROH produced is calculated by dividing the total amount of alcohol produced by the total amount of C ２＋ The total amount of ROH produced means the total amount of alcohols produced having two or more carbon atoms. ２＋ The alcohol selectivity means the selectivity of alcohols having two or more carbon atoms, and differs from the alcohol selectivity in that it does not include methanol.

[0060]

[0061] From the above, it was found that in the alcohol production method of the present embodiment, by setting the production conditions of the obtained catalyst to predetermined conditions, the alcohol selectivity can be improved when alcohol is produced from synthesis gas using the catalyst.

Claims

1. A method for producing an alcohol, comprising the following steps 1 and 2: Step 1: a catalyst production step in which a cobalt-containing compound (a) and a copper-containing compound (b), both soluble in a protic solvent, are mixed in the protic solvent so that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol, and the mixture is reacted with a divalent or higher carboxylic acid compound (c), thereby obtaining a catalyst from the reaction product; and Step 2: an alcohol production step in which a synthesis gas is reacted in the presence of the catalyst obtained in Step 1 to obtain an alcohol.

2. The method for producing an alcohol according to claim 1, wherein the relative dielectric constant of the protic solvent at 20°C is 3.0 or more and 85.0 or less.

3. The method for producing an alcohol according to claim 2, wherein the protic solvent comprises at least one selected from the group consisting of water, ethanol, and isopropanol.

4. The method for producing alcohol according to any one of claims 1 to 3, wherein (c) contains one or more acids selected from the group consisting of oxalic acid and citric acid.

5. The method for producing an alcohol according to any one of claims 1 to 4, wherein step 1 is a catalyst production step comprising mixing a cobalt-containing compound (a) and a copper-containing compound (b), both soluble in a protic solvent, in a protic solvent such that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol, and then coprecipitating the mixture with a precipitating agent containing a divalent or higher carboxylic acid compound (c), and then obtaining a catalyst from the coprecipitated reaction product.

6. The method for producing an alcohol according to any one of claims 1 to 5, wherein step 1 comprises the following steps 1a, 1b, and 1c: step 1a: obtaining a raw material solution by uniformly dissolving the cobalt-containing compound (a) and the copper-containing compound (b) in the protic solvent so that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol; step 1b: obtaining a precipitant solution by dissolving the precipitant in the protic solvent; and step 1c: mixing the raw material solution obtained in step 1a with the precipitant solution obtained in step 1b to co-precipitate the cobalt-containing compound (a) and the copper-containing compound (b).

7. The method for producing alcohol according to any one of claims 1 to 6, wherein step 2 is carried out in a slurry bed reactor.

8. A method for producing a catalyst, comprising: mixing a cobalt-containing compound (a) and a copper-containing compound (b) soluble in a protic solvent in such a manner that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol; reacting the resulting mixture with a divalent or higher carboxylic acid compound (c); and obtaining a catalyst from the reaction product.

9. A cobalt-containing compound (a) and a copper-containing compound (b), both soluble in the protic solvent, are mixed in a protic solvent so that the amount of copper per 1 mol of cobalt is 0.2 mol to 0.7 mol, and the mixture is reacted with a divalent or higher carboxylic acid compound (c), and the catalyst obtained from the reaction product is used to produce alcohol by reacting carbon monoxide and hydrogen in a synthesis gas.

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