JPS628417B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing oxygen-containing compounds by reacting synthesis gas in the presence of a Ru compound catalyst. More specifically, the present invention relates to an efficient method for producing an oxygen-containing compound, characterized in that the reaction is carried out in the presence of a bisphosphonium salt additive having two positive charges in the molecule. The so-called _C1 chemical technology that produces ethanol and ethylene glycol from synthesis gas, which can be produced from a variety of raw materials such as heavy oil and coal, is an alternative to the conventional petrochemical technology that uses ethylene, propylene, etc. as raw materials. It is expected that it will play a role in the chemical industry, and catalyst development for this purpose is being competed.
Various methods have been proposed for producing oxygen-containing compounds from synthesis gas using ruthenium catalysts, and it is also known that halogen-containing phosphonium salts are effective additives. That is, in JP-A No. 58-29728, synthesis gas is reacted using a Ru catalyst in the presence of (C ₆ H ₅ ) ₄ PCl, (C ₆ H ₅ ) ₃ CH ₃ PI, and Et ₄ PI,
A method for obtaining ethanol, ethylene glycol, etc. is disclosed. Further, JP-A-57-82327 discloses a method using tripropylphosphine oxide as a solvent and adding (CH ₃ ) ₄ PCl.Br or I as an additive. Furthermore, JFKnifton is Ru
Catalysts - It has been reported that various phosphonium salt additives are effective in the reaction of reducing carbon oxide with hydrogen to obtain acetate esters of oxygen-containing compounds. However, these phosphonium salts have a small activity improvement effect when added in small amounts and do not produce oxygen-containing compounds advantageously, so expensive phosphonium salts are required.
It is necessary to use a large amount in excess of Ru, and this cannot be said to be an industrially advantageous method. In order to avoid such drawbacks in the prior art, the present inventors have conducted intensive research on the structure of phosphonium salts, and found that when using the bisphosphonium salt represented by the above general formula () as an additive, The inventors discovered a novel phenomenon in which a higher activity is expressed than the corresponding monophosphonium salt, and based on this knowledge, completed the present invention. That is, the present invention provides an efficient method for producing a C ₂ -oxygen-containing compound from synthesis gas in the presence of a Ru catalyst and using a bisphosphonium salt as an additive. As the Ru compound used as a catalyst in the method of the present invention, any compound that can form a ruthenium carbonyl derivative or a ruthenium carbonyl derivative under the reaction conditions of pressurized synthesis gas can be used. Such ruthenium compounds include various ruthenium complexes, ruthenium inorganic or organic salts, oxides, and the like. Suitable ruthenium compounds include Ru ₃ (CO) ₁₂ , Ru (CO) ₅ , Ru
(CO) ₃ (PPh ₃ ) ₂ , Ru (CO) ₃ Cl ₂ , Ru
(CO) ₃ Br ₂ , Ru(CO) ₃ I ₂ , Cs [Ru(CO) ₃ Cl ₃ ],
PPN [HRu ₃ (CO) ₁₁ ], PPN [HRu (CO) ₄ ],
(1,3,5-cyclooctatriene)(1,5-
cyclooctadiene)ruthenium, _RuCl2
(CO) ₂ (PPh ₃ ) ₂ , [Ru(CO) ₃ Cl ₂ ] _o , RuCl ₃ ,
RuBr ₃ , RuI ₃ , Ru(OAc) ₃ , Ru(acac) ₃ , Ru
Examples include (NO ₃ ) ₃ , RuO ₂ , RuO ₄ and the like. It is also possible to use finely powdered or colloidal ruthenium metal which can form ruthenium carbonyl in the reaction system. The amount of ruthenium catalyst used is 10 ^-7 per ruthenium metal per 10 ml of solvent.
1 g atom, preferably from 10 ⁻⁵ to 10 ⁻² g atom. The organic group R of the bisphosphonium salt represented by the general formula () used in the present invention is not particularly limited, and includes methyl, ethyl, butyl, phenyl, benzyl,
Examples include cyclohexyl. In addition, in the divalent organic group represented by A in the same general formula (), if the number of carbon atoms between two phosphorus atoms is too large, the activity-improving effect will be small compared to a monophosphonium salt. A hydrocarbon chain having a number of C ₁₂ or less and bonding two phosphorus atoms is preferred. Note that the carbon chain here refers to the shortest carbon chain that connects two phosphorus atoms. Further, even if a side chain or various functional groups are bonded to this carbon chain, this does not in any way hinder the implementation of the method of the present invention. Suitable bisphosphonium salts include, for example Ph ₃ P
(CH ₂ ) _o PPh ₃・2X (n is a positive integer of 1≦n≦12, X is Cl, Br, or I), Bu ₃ P
(CH ₃ ) _o PBu ₃・2X (n and X are the same as above),

[Formula] (X is the same as above),

[Formula] (X is the same as above), etc. are included. The amount of these bisphosphonium salts to be used is calculated in terms of the ratio P/Ru of the phosphorus atoms contained therein and the ruthenium atoms contained in the ruthenium catalyst.
It is 0.5 or more, and the preferred range is 1≦P/R≦100. The reaction according to the process of the invention is carried out at a temperature of 100 DEG to 350 DEG C., preferably 150 DEG to 300 DEG C. In addition, the pressure of synthesis gas is 50 to 2000 atmospheres or more,
Preferably, the pressure is in the range of 100 to 1000 atmospheres, and the gas composition is determined by integrating activity and selectivity, since reaction activity increases when the partial pressure of _H2 is high, but by-products such as methane also tend to increase. However, CO/H ₂ is usually set between 5 and 1/10, and the preferred range is between 2 and 1/5. Various solvents can be suitably used in the present invention, including solvents conventionally used in the synthesis of oxygen-containing compounds from synthesis gas. Examples of these include ethers such as tetrahydrofuran, diglyme, and tetraglyme, esters such as ethyl acetate, and γ-butyrolactone;
dimethylformamide, N-methylpyrrolidone,
Amides or ureas such as N-isobuipylpyrrolidone, tetramethylurea, dimethylimidazolidinone, aromatic hydrocarbons such as benzene, toluene, xylene, tripropylphosphine oxide, tributylphosphine oxide, hexamethylphosphoric Examples include phosphine oxides such as triamide, acetonitrile, and sulfolane. The _C2 -oxygenated compounds obtained by the present invention include ethanol, ethylene glycol, etc., and these can be easily separated by commonly used methods such as distillation or extraction of the reaction solution. Next, the embodiments of the present invention will be described in more detail with reference to Examples. Example 1 In a Hastelloy C micro cylinder with an internal volume of 40 ml,
Ru ₃ (CO) ₁₂ at 0.1 mg−atom per Ru atom,
(C ₆ H ₅ ) ₃ P-(CH ₂ ) ₂ -P(C ₆ H ₅ ) 3.2Br converted to phosphorus atom was charged with 0.2 mg _of atom, and 10 ml of N-isopropylpyrrolidone was used as a solvent. in
By pressurizing 300 atm of synthesis gas (CO/H ₂ = 1)
As a result of reacting at 230°C for 3 hours, the following reaction results were obtained. Ethanol production amount 1.321mmol Ethylene glycol production amount 0.61mmol Comparative example 1 (C ₆ H ₅ ) ₃ P (n−C ₄ H ₉ ) Br (C ₆ H ₅ ) ₃ P−
When the reaction was carried out in the same manner as in Example 1 except that (CH ₂ ) ₂ -P(C ₆ H ₅ ) _3.2Br was used, the reaction results were as follows: ethanol production: 0.42 mmol; ethylene glycol production: 0.27 mmol. Nakatsuta. Example 2 - (C ₆ H ₅ ) ₃ P-(CH ₂ ) ₂ -P(C ₆ H ₅ ) 3.Results of reaction in the same manner as in Example 1 using various bisphosphonium salts in place of 2Br _. are shown in Table 1.

[Table] Example 6 (C ₆ H ₅ ) ₃ P-(CH ₂ ) ₂ -P(C ₆ H ₅ ) Instead of ₃・2Br (n-C ₄ H ₉ ) ₃ P-(CH ₂ ) ₂ −P(n−C ₄ H ₉ ) ₃・
When the reaction was carried out in the same manner as in Example 1 except for using 2Br, 0.47 mmol of ethanol was produced. Comparative Example 2 (n-C ₄ H ₉ ) ₄ PBr (n-C ₄ H ₉ ) ₃ P-(CH ₂ ) ₂ −
The reaction was carried out in the same manner as in Example 6 using P( _n -C ₄ H ₉ ) 3.2Br instead, and the amount of ethanol produced was
It was only 0.27 mmol. Example 7 (C ₆ H ₅ ) ₃ P−(CH ₂ ) ₂ −P(C ₆ H ₅ ) ₃・2Br was replaced with (C ₆ H ₅ ) ₂ (CH ₃ )P−CH ₂ −P(CH ₃ )
When the reaction was carried out in the same manner as in Example 1 except that (C ₆ H ₅ ) ₂ ·2Br was used, 7.3 mmol and 1.1 mmol of ethanol and ethylene glycol were produced, respectively.

Claims (1)

[Claims] 1 In reacting carbon monoxide with hydrogen using a Ru compound as a catalyst, the general formula () R ₃ P-A-PR ₃・2X () (R is an alkyl group, a cycloalkyl group, It represents an organic group selected from the group consisting of an aryl group and an aralkyl group, and the three R's may be the same or different, and A may be a branched alkylene group, a cycloalkylene group, a phenylene group, Indicates a divalent organic group selected from the group consisting of aralkylene groups,
represents a halogen atom) A method for producing a C ₂ -oxygen-containing compound, characterized in that the reaction is carried out in the presence of a bisphosphonium salt represented by: 2 Partial pressure ratio of carbon monoxide and hydrogen is 1:20 to 10:1
The method according to claim 1, wherein the total pressure is between 100 and 2000 atm and the reaction temperature is between 150 and 300C. 3. The method according to claim 1, wherein the bisphosphonium salt is added at a ratio of 0.5 mol/g-atom or more to the amount of ruthenium in the ruthenium catalyst. 4. The method according to claim 1, wherein the halogen atom X of the bisphosphonium salt is chlorine, bromine or iodine.