JPS6346052B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD OF THE INVENTION The present invention relates to a method for producing monohydric alcohols, particularly methanol and ethanol, directly from carbon monoxide and hydrogen. Alcohol is an industrially important substance and is used for a variety of purposes, including as an intermediate and solvent for the production of many chemical substances. (Prior Art) Methods for producing methanol and/or ethanol in the presence of a ruthenium-containing catalyst are known. For example, JP-A-55-9088 and JP-A No. 55-9088
The method of No. 104217 discloses a method for producing alcohols as esters with a carboxylic acid solvent by using a catalyst consisting of ruthenium and/or osmium in a carboxylic acid-containing liquid solvent. Also, JP-A No. 57-123128, No. 58-
No. 921, No. 58-922, No. 58-8026 and US
P.4436838 discloses a method for producing alcohol using a ruthenium-based binary catalyst containing ruthenium and other metals. Among these, US
The method in P.4436838 discloses a method using ruthenium as the main catalyst and a vanadium compound as the second metal, but the method uses a special catalyst that requires the presence of a quaternary phosphonium salt as a molten salt. system, and no significant effect has been observed by adding vanadium compounds. Furthermore, quaternary phosphonium salts are considered to be thermally unstable and cannot be said to be a preferable catalyst system from an industrial standpoint. Furthermore, the methods disclosed in JP-A-55-115834 and JP-A-56-166133 are methods for producing alcohol and acetaldehyde using ruthenium catalysts, in which a halogen salt is used as a cocatalyst and ethers or aprotic organic amides are used as a solvent. Organic phosphine oxides are preferably used as liquid catalysts in JP-A-57-82837. (Problems to be Solved by the Invention) The methods known to date for producing methanol and ethanol directly from carbon monoxide and hydrogen do not have sufficient selectivity and activity, and have yet to be industrialized. do not have. (Means for Solving the Problems) As a result of intensive study on a method for industrially producing alcohol directly from carbon monoxide and hydrogen, the present inventors found that The present invention was completed based on the discovery that methanol and ethanol can be obtained selectively and efficiently by reacting in a protic polar solvent. That is, the present invention is a method for producing a monohydric alcohol, which is characterized by reacting carbon monoxide and hydrogen under pressure in an aprotic polar solvent containing a ruthenium compound, a hydrogen halide, and a vanadium compound. According to the method of the present invention, there is no need to use a promoter such as a quaternary onium salt, which is considered to be thermally unstable, and therefore it is considered to be a stable and excellent method from an industrial viewpoint. Examples of vanadium compounds used in the method of the invention can be selected from compounds such as inorganic compounds, organic compounds and complexes. That is, examples of inorganic compounds include vanadium oxides such as vanadium trioxide () and vanadium pentoxide (), vanadyl sulfate, vanadyl nitrate, vanadium trichloride, vanadium tetrachloride, vanadyl dichloride, vanadyl trichloride, and vanadium trichloride. Examples include mineral acid salts such as vanadium oxide and vanadium triiodide. Further examples include vanadate salts such as sodium vanadate and ammonium vanadate. Examples of organic compounds that can be used include organic acid salts such as vanadyl oxalate, and alkoxides such as vanadyl triethoxide. Examples of complexes include vanadium acetylacetonate, vanadyl acetylacetonate, bis(cyclopentadienyl)vanadium, bis(cyclopentadienyl)vanadium chloride, cyclopentadienylvanadium tetracarbonyl, vanadium hexacarbonyl, etc. Other examples include vanadium complexes in which vanadium is coordinated with various ligands. Among these vanadium compounds, vanadium oxide, vanadium halide, vanadium carbonyl, vanadium organic acid salt, vanadate,
Preferable examples include vanadium complexes in which at least some of the carbon monoxide ligands of vanadium acetylacetonate, vanadyl acetylacetonate, or vanadyl carbonyl are replaced with other ligands. The amount of vanadium compound used is 0.01 to 50 times, preferably 0.1 to 20 times, in atomic ratio to ruthenium.
More preferably, it is in the range of 0.1 to 10 times. As the ruthenium compound used in the present invention, a wide variety of compounds can be used that can generate a ruthenium complex having carbon monoxide as a ligand under reaction conditions. For example, in addition to metal ruthenium,
Ruthenium oxides such as ruthenium dioxide and ruthenium tetroxide, their hydrates, mineral acid salts of ruthenium such as ruthenium chloride, ruthenium iodide, and ruthenium nitrate, organic acid salts of ruthenium such as ruthenium acetate and ruthenium propionate, etc. There is. Ruthenium compounds can also be used directly in the form of coordination compounds, examples of which include ruthenium carbonyl, such as triruthenium dodecacarbonyl, and ruthenium combined with oxygen, sulfur, halogens, nitrogen, phosphorous, arsenic, etc. Examples include ruthenium complexes coordinated with ligands containing , antimony, bismuth, etc., and salts thereof. Among these ruthenium compounds, ruthenium oxide, ruthenium halide, ruthenium carbonyl, ruthenium acetylacetonate,
Alternatively, a ruthenium complex in which at least some of the carbon monoxide ligands of ruthenium carbonyl are replaced with other ligands is preferable. The concentration of the ruthenium compound used in the method of the present invention in the liquid medium is 0.1 parts by weight per 1000 parts by weight of the liquid medium, expressed as ruthenium metal.
~100 parts by weight. The hydrogen halide used in the present invention may be any hydrogen halide as long as it can generate hydrogen halide (HCl, HBr, and HI) under the reaction conditions, and examples thereof include the following. (1) Halogens and acids: halogens such as Cl ₂ , Br ₂ , I ₂ , hydrogen halides such as HCl, HBr, HI,
HClO, _HClO2 , _HClO3 , _HBrO3 , _HIO3 ,
Examples include oxyacids such as _HClO4 . Among these, halogen and hydrogen halide are usually preferably used. (2) Organic halides: alkyl halides such as methyl chloride, methyl bromide, methyl iodide, methane dichloride, methane dibromide, chloroform, carbon tetrachloride, ethane dibromide, butane iodide,
Acyl halides such as acetyl chloride, acetyl bromide, acetyl iodide, benzoyl bromide,
Aromatic halides such as benzyl chloride, benzyl bromide, and benzene iodide, as well as various halides such as benzenesulfonyl chloride and fucurimide bromide are used. Usually, alkyl halides, acyl halides, benzyl halides, etc. can be suitably used. The amount of hydrogen halide added is 0.01 to 20 halogen atoms based on the number of gram atoms of ruthenium.
times, preferably 0.1 to 10 times, more preferably,
The atomic ratio ranges from 0.1 to 5 times. The aprotic polar solvent used in the method of the present invention is preferably an N-substituted amide, a urea derivative, or a phosphine oxide. Examples of such include N-substituted amides such as N-methylpyrrolidin-2-one, N-ethylpyrrolidin-2-one, N,N-dimethylacetamide, N-methylpyrrolidone, and hexamethylphosphorictriamide. , tetramethylurea, tetraethylurea, 1,
Urea derivatives such as 3-dimethyl-2-imidazolidinone, phosphine oxides such as triethylphosphine oxide, tripropylphosphine oxide, tributylphosphine oxide, trihexylphosphine oxide, trioctylphosphine oxide, triphenylphosphine oxide, etc. Examples include inoxides. These solvents can be used alone or as a mixed solvent. Furthermore, a solvent mixed with alcohols, carboxylic acids, etc., which are reaction products of the method of the present invention, can also be used. Therefore, the reaction liquid taken out from the reactor can be circulated and supplied to the reactor again as a liquid catalyst. In the method of the present invention, the reaction temperature is in the range of 150 to 350°C, preferably 170 to 300°C, and the reaction pressure is usually in the range of 30°C.
~1000Kg/ ^cm2 gauge, preferably 80-600Kg/ ^cm2
It can be fully implemented within the gauge range. The molar ratio of carbon monoxide and hydrogen used as raw materials is preferably in the range of 1:10 to 10:1. Furthermore, there is no problem even if other components inactive to the reaction, such as methane, nitrogen, etc., are present in the raw material synthesis gas. The method of the present invention can be carried out either batchwise or semi-continuously. The ruthenium compound, hydrogen halide, vanadium compound, solvent, etc. may be added to the reactor in batch mode, or may be fed in semi-continuous mode or semi-continuous mode. The product can be removed by known methods such as distillation, stripping, etc. Further, if necessary, the liquid medium containing the ruthenium compound, hydrogen halide, vanadium compound, solvent, etc. can be recycled to the reactor and used again. (Function) In the method of the present invention, carbon monoxide and hydrogen are added to a catalyst system consisting of a vanadium compound, a ruthenium compound, and a hydrogen halide to cause a reaction, which increases the production rate of ethanol and/or ethanol and increases the total production rate of ethanol. It has the effect of increasing the selectivity of methanol and ethanol to liquid products. Therefore, in the prior art, it was necessary to use a co-catalyst such as a thermally unstable quaternary onium salt in a system containing a ruthenium compound as the main catalyst, but with the method of the present invention, This is an excellent and industrially stable method, as there is no need for it. (Example) Hereinafter, the method of the present invention will be explained in more detail with reference to Examples. In the examples, unless otherwise specified, triruthenium dodecacarbonyl is used as the ruthenium compound, the amount of ruthenium used is expressed in milligram atoms, and the amount of hydrogen halide and vanadium compound used is the molar ratio ( or atomic ratio). Further, as a solvent, tributylphosphine oxide (7.0 g) was used unless otherwise specified, and the reaction was carried out at 220°C unless otherwise specified. In addition, the production rate of the product is expressed as the turnover number (expressed as TON) [mol-CO/Ru (g-atoms)/hr]
The selectivity is [TON (methanol) + TON
(ethanol)/total liquid product - TON] x 100. Furthermore, in the table the products are designated as methanol, ethanol and propanol, including those produced as carboxylic esters and dimethyl ethers. Moreover, in the table, each symbol represents the following compound. acac: acetylacetone, Bu ₃ PO: tributylphosphine oxide, (Oct) ₃ PO: trioctylphosphine oxide, DMI: 1,3-dimethyl-2-imidazolidinone, NMP: N-methylpyrrolidin-2-one, V (acac) ₃ : vanadium acetylacetonate, VO (acac) ₂ : vanadyl acetylacetonate, NaVO ₃ : sodium vanadate, V ₂ O ₃ : vanadium trioxide (),
VO _{( C2O4 )} : vanadyl oxalate, _NH4VO3 : ammonium vanadate, _Ru3 (CO) ₁₂ : dodecacarbonyl triruthenium, Ru(acac) ₃ : ruthenium acetylacetonate, HBr: hydrogen bromide, _I2 : Iodine. Example 1 In a stainless steel autoclave with an internal volume of 50ml,
Ruthenium carbonyl 0.15 g (0.70 milligram atom as Ru), 47% hydrogen bromide aqueous solution 0.12 _to 0.70 mmol), vanadium acetylacetonate 0.24 g
(0.7 milligram atom as V) and tri-n-
After charging 7.0 g of butylphosphine oxide and introducing synthesis gas (CO:H ₂ = 1:1) to replace the air in the autoclave, the synthesis gas was
It was charged up to Kg/cm ² gauge (room temperature). Next, the autoclave was heated, and when the internal temperature reached 80°C, stirring was started, and when the internal temperature reached 220°C, the temperature was maintained at a constant temperature to allow reaction. When the internal pressure of the autoclave dropped by 100 kg/cm ² gauge from the maximum pressure, heating was stopped and the autoclave was cooled to room temperature. The contents were then removed and analyzed by gas chromatography. The liquid phase contains 6.5 mmol of methanol, 7.9 mmol of ethanol, 0.8 mmol of propanol, 0.1 mmol of butanol, and acetaldehyde.
0.1 mmol of methyl formate, 0.1 mmol of ethyl formate, 0.3 mmol of methyl acetate, 0.2 mmol of dimethyl ether, and 0.1 mmol of diethyl ether were detected in the gas phase.
12.0 mmol of methane was detected. The reaction conditions and results are summarized in Table 1. Examples 2 to 19 and Comparative Examples 1 to 3 In Example 1, the reaction was carried out by changing the types of ruthenium compound, hydrogen halide, vanadium compound, and solvent as shown in Table 1. These results are shown in Table 1.

【table】

[Table] (Effects of the invention) When vanadium acetylacetonate and vanadyl acetylacetonate are added to the ruthenium-hydrogen halide-tributylphosphine oxide catalyst (Comparative Example 1) (Examples 1 to 4), methanol and ethanol are produced. It can be seen that the speed and selectivity between methanol and ethanol are improved. Comparative Examples 2 and 3 showed the influence of acetylacetone, but the effect was very small compared to the case of vanadium acetylacetonate or vanadyl acetylacetonate. Examples 5 to 15 show the effects of various vanadium compounds. It can be seen that, compared to Comparative Example 1, the addition of the vanadium compound improves the methanol and ethanol production rate and the selectivity between methanol and ethanol. Examples 16 to 19 are the results of changing the type of hydrogen halide and the type of solvent as shown in Table 1, but even under these conditions, high production rate and high selectivity of methanol and ethanol were achieved. shows that it can be achieved. As shown above, when carbon monoxide and hydrogen are reacted under heat and pressure in an aprotic polar solvent containing a ruthenium compound and hydrogen halide, methanol can be produced by using a vanadium compound as an additive. , it was shown that a high production rate and selectivity of ethanol could be obtained.

Claims (1)

[Claims] 1. A method for producing a monohydric alcohol, which comprises reacting carbon monoxide and hydrogen under pressure in an aprotic polar solvent containing a ruthenium compound, a hydrogen halide, and a vanadium compound.