JPS6351130B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for synthesizing oxygen-containing organic compounds such as methanol, ethylene glycol, and methyl formate from carbon monoxide and hydrogen. Using carbon monoxide and hydrogen as raw materials, methanol,
Methods for synthesizing oxygen-containing organic compounds such as ethylene glycol and methyl formate have been known for a long time.
It is particularly practiced as an industrial method for synthesizing methanol, and many proposals have been made regarding its catalyst. Methanol synthesis from carbon monoxide and hydrogen is reported in detail by G.Natta (Catalysis Vo13 p349, Reinhold Publishing
Co., New York, 1955) That is, in the reaction of the following equation, the free energy change of CO + 2H ₂ → CH ₃ OH (1) is positive at temperatures above 180°C, and becomes unbalanced at higher temperatures. Therefore, high pressure is required in order for formula (1) to proceed more favorably, and if a methanol synthesis catalyst with high activity at lower temperatures is developed, the reaction can proceed even at lower pressures, making methanol economically advantageous. This is a synthetic method. For example, with the Zn/Cr oxide catalyst formerly known as the BASF method, the
Whereas the so-called low-pressure method discovered by ICI required a pressure of 350atm, the pressure was 240-280℃ and 50-50atm.
It has become possible to synthesize methanol at 100 atm, and it is currently being adopted as an industrial process in many parts of the world. However, the critical temperature of methanol is 240°C, and even in the ICI low pressure method, the reaction is carried out in a substantially gaseous state, thereby employing a gas phase catalytic reaction. However, even at 240°C, the equilibrium concentration of methanol is only about 40%, and in actual industrial processes, the methanol concentration at the outlet of the reactor is less than 10%. For this reason, the gas leaving the reactor is cooled once,
In addition to separating methanol, a large amount of unreacted synthesis gas must be recycled and reused, which is said to require a large amount of energy. The present inventors investigated reactions using carbon monoxide and hydrogen as raw materials, and found that by using a catalyst that combines specific compounds, not only methanol but also methyl formate can be produced even under low temperature conditions of 200°C or less.
It has been found that oxygenated compounds such as ethylene glycol, ethanol, methyl acetate, propanediol, butanediol, etc. can be obtained. This method enables liquid phase synthesis, which simplifies heat removal, which is one of the problems of conventional methods, and also makes it easy to separate and obtain the product, and virtually eliminates the need to recycle large amounts of unreacted gas. The present invention has been completed based on the discovery that the present invention can be achieved. That is, the present invention relates to a method for synthesizing an oxygen-containing organic compound by reacting carbon monoxide and hydrogen, which is characterized by using a catalyst consisting of a copper compound other than copper oxide and an alkali metal alkoxide. The catalyst used in the present invention may be prepared by mixing the copper compound and the alkali metal alkoxide in advance, or each component may be separately supplied to the reaction system. During preparation, it is preferable to use a liquid organic diluent under the preparation conditions, and a catalyst with excellent performance can be obtained. These may be used to form a copper alcoholate or the like intermediately in the blending system. The copper compounds used in the present invention are copper compounds other than copper oxides such as cuprous oxide and cupric oxide, and specifically include copper methoxide, copper ethoxide, copper iso-propoxide, Copper () and copper () such as copper tert-butoxide and copper octoxide
Alkoxides with about 1 to 10 carbon atoms, copper phenoxides, copper allyl oxides such as copper-P-toroxide, copper halides such as cuprous chloride, cupric chloride, cuprous bromide, cuprous iodide, etc. and its hydrates, copper carboxylates such as copper sulfate, copper hydroxide, copper acetylacetonate, copper acetate, copper propionate, and copper hydrides. Among these, copper alkoxides, copper halides, and copper carboxylates are preferred. The other alkali metal alkoxide is preferably a linear alcohol alkali metal alkoxide, such as sodium methoxide, lithium methoxide, potassium methoxide,
Sodium ethoxide, lithium ethoxide, potassium ethoxide, sodium-n-propoxide, lithium-n-propoxide, potassium-n
-propoxide, sodium-n-butoxide, etc. Among these, alkali metal methoxide is preferred, and sodium is preferred as the alkali metal. In the present invention, other compounds may be combined as necessary to increase the catalytic activity,
Efforts are made to extend the lifespan and to adjust the type, composition, etc. of the oxygen-containing organic compound produced. That is, magnesium, aluminum, manganese,
and titanium compounds. Further, by combining an alkali metal carboxylate such as potassium acetate, the composition ratio of ethylene glycol in the produced oxygen-containing organic compound can be significantly increased. In this case, the reaction temperature is preferably in the range of about 85°C to 140°C. The catalyst system of the present invention may be prepared by mixing each component in advance, or each component may be individually supplied into the reaction system with or without an organic diluent. be exposed. The organic diluent for preparing the catalyst may be arbitrarily selected, except for those that immediately react with the alkali metal alkoxide and substantially consume the catalyst components.
Any substance that is normally liquid can be used. Specifically, dimethyl ether of diethylene glycol, dimethyl ether of tetraethylene glycol (tetraglyme), dimethyl ether,
Ethers such as diethyl ether and 1,2-dimethoxybenzene, esters such as γ-butyrolactone, dimethyl-γ-butyrolactone, and γ-valerolactone, sulfone compounds such as sulfolane, dimethylsulfone, and tetramethylsulfone, glycolic acid, methoxy Carboxylic acids such as acetic acid, ethoxyacetic acid, diglycolic acid, thioglycolic acid, citric acid, alcohols such as methanol, ethanol, 2-methoxyethanol, saturated and unsaturated substances such as hexane, heptane, hexane, cyclohexane, naphtha, kerosene, etc. Hydrocarbons include aromatic hydrocarbons such as benzene, toluene, and xylene. The reaction of the present invention is preferably carried out in the presence of a reaction medium that is in a liquid phase under the reaction conditions. As the reaction medium, the organic diluent used in the preparation of the catalyst may be used as is, or an additional amount of solvent may be added. Furthermore, after adjusting the catalyst using an organic diluent, this organic diluent can be replaced with another solvent and used as a reaction medium as it is. The solvent used for the above purpose is not limited to those exemplified above that can be used as organic diluents, but may also be alcohols such as methanol, ethanol, propanol, and butanol. The amounts of copper compounds, alkali metal alkoxides or further additives added to these reaction media can vary within wide limits. Generally, about 0.001 to 10 mol of copper compound per 1 part of the reaction medium,
Approximately 0.001 to 10 moles of alkali metal alkoxide are blended. The blending ratio of the copper compound and the alkali metal alkoxide may be changed as necessary depending on the type and composition of the desired product. Among these, it is preferable to set the molar ratio of alkali metal alkoxide/copper compound to about 2 or more, particularly about 3 to 50, in order to increase the amount of each product produced. In addition, magnesium, aluminum,
The metal compound selected from manganese and titanium is preferably used in an amount of about 2 mol or less, particularly about 0.001 to 1 mol, based on the reaction medium. The other suitably incorporated compound, the alkali metal carboxylate, is in a molar ratio (alkali metal carboxylate/copper compound) to the copper compound used.
It is preferably about 5 or less, particularly about 0.5 to 4. The molar ratio of carbon monoxide/hydrogen gas supplied to the catalyst system can vary widely depending on the type of oxygen-containing compound desired, but is usually about 2/1 to 1/2.
It is about 5. When the purpose is to synthesize methyl formate, the ratio is preferably 1.5/1 to 1/1.5, and when the purpose is to synthesize methanol, the ratio is preferably 1/1.5 to 1/2.5. The method of the present invention exhibits activity at lower temperatures than conventional methanol synthesis catalysts, and is less than about 200°C, especially from 40°C to
Shows sufficient catalytic activity at 185℃. Considering that conventional methanol synthesis catalysts require temperatures of substantially 230° C. or higher, it is clear that the present invention represents a significant inventive step. In addition, to increase the production rate of methyl formate,
It is desirable that the reaction temperature is about 150°C or less,
For the production of ethylene glycol, the reaction temperature is approximately 80°C.
The temperature is preferably 150°C. It is a common phenomenon in this type of reaction that the higher the reaction pressure, the higher the reaction rate, and in the present invention, the pressure can be set to any pressure above normal pressure. Usually less than 200Kg/ ^cm2 , preferably 20
It is desirable to set it to ~150Kg/ ^cm2 . In any case, the reaction temperature and reaction pressure should be determined based on a comprehensive economic evaluation of the cost of high-pressure equipment, energy cost, and productivity. Generally, when the reaction pressure is increased, the amount of raw material gas consumed increases, and the amount of produced oxygen-containing organic compounds such as methanol and methyl formate also increases. The present invention can be carried out in any batch, semi-continuous or continuous manner. The raw material gas is supplied to the catalyst system and can be brought into contact with the catalyst by a method such as bubbling, but desirable results can be obtained by using rocking, shaking, stirring, or other methods in combination to further improve the contact efficiency. In the present invention, since the reaction can be carried out in the liquid phase, the synthesized oxygen-containing compound can be produced by extractive distillation, etc. by sequentially extracting part or all of the liquid phase reaction mixture without substantially accompanying the raw material gas. It can be separated by Therefore, it is not necessary to circulate a large amount of unreacted gas, which is inevitably entrained in the conventional gas phase reaction when removing the oxygen-containing compound. Further, the catalyst accompanying the oxygen-containing compound can be separated by sedimentation or the like and reused in the reaction. As described above, the present invention is based on the type and proportion of the catalyst,
The type and composition of oxygen-containing organic compounds such as methanol, methyl formate, ethylene glycol, ethanol, methyl acetate, propanediol, and butadiol can be changed as appropriate by appropriately selecting the compounds used in combination, reaction gas composition, reaction temperature, etc. can. Furthermore, heat removal, which is one of the problems of the conventional method, can be facilitated, and furthermore, the circulation of large amounts of unreacted gas can be substantially eliminated. Among the oxygen-containing organic compounds obtained in the present invention, methyl formate is a substance that has traditionally attracted attention as a raw material for synthesizing acetic acid through its rearrangement reaction.
The synthesis of methyl formate has conventionally been carried out by a reaction between methanol and carbon monoxide in the presence of an alkali catalyst, or by an oxidative dehydrogenation reaction of two molecules of methanol in the presence of a copper catalyst. In contrast, according to the present invention, methyl formate can be directly synthesized from carbon monoxide and hydrogen. According to the present invention, compared to conventional methods, methanol,
Methyl formate, ethylene glycol, ethanol,
Oxygen-containing organic compounds such as methyl acetate, propanediol, and butanediol can be efficiently produced under relatively mild conditions. Hereinafter, the present invention will be explained in more detail with reference to Examples. Examples 1 to 4 and Comparative Examples 1 and 2 After purging the inside of a stainless steel autoclave with a capacity of 50 ml with argon, 1 mmol of cuprous chloride, 11 mmol of sodium methoxide, and 10 ml of tetrahydrofuran were placed inside the autoclave, and the autoclave was heated. closed. A mixed gas of carbon monoxide/hydrogen with a molar ratio of 3/7 was introduced into this autoclave from the gas inlet pipe until the pressure inside the reaction system was 70 kg/cm ² -
After the autoclave and its contents were heated to 80° C. with stirring. The pressure drops immediately when the temperature is raised, but carbon monoxide and hydrogen (CO/H ₂ = 3/7 molar ratio) are added as needed.
Increase the internal pressure of the autoclave by adding
Kg/cm ² -G was maintained and the reaction was carried out for 8 hours. The total pressure drop during the reaction period was 273 Kg/cm ² . After the reaction was completed, the mixture was cooled to room temperature, excess gas was discharged into a gas retainer, and the reaction mixture was taken out. This was quantified by gas chromatography, and analysis of the gas phase showed 2% CO2 _and 78% H2, and analysis of the product of the reaction mixture is shown in Table 1 as Example 1. Further, the same procedure as in Example 1 was carried out by changing the composition of the mixed gas, the reaction temperature, and the reaction time. The results are shown in Table 1.

[Table] Examples 5 to 11 and Comparative Example 3 The same procedure as in Example 1 was conducted except that the types of copper compound and alkali metal alkoxide were changed. However, the reaction conditions are as follows. CO/H ₂ molar ratio =
1/1, reaction temperature 125℃, reaction pressure 60-80Kg/cm ²

[Table] Examples 12 and 13 The same procedure as in Example 1 was carried out except that the amount of sodium methoxide was changed relative to 1 mmol of cuprous chloride. The results are shown in Table 3. However, the reaction conditions are as follows. Co/H ₂ molar ratio = 1/1, reaction temperature 125℃, reaction pressure 60-80Kg/cm ² , reaction time 5 hours

[Table] Examples 14 to 17 In order to examine the influence of reaction pressure, reactions were carried out at the pressures shown in Table 4. However, the reaction conditions are as follows. CO/H ₂ = (molar ratio) = 1/1, reaction temperature 125°C,
Reaction time 5 hours

[Table] Examples 18 to 22 The same procedure as in Example 1 was carried out except that other metal compounds were combined and blended. However, the reaction conditions are as follows. CO/H ₂ (molar ratio) = 1/1, reaction temperature 125°C,
Reaction pressure 60-80Kg/cm ² ,

[Table] Examples 23 to 28 The same procedure as in Example 5 was carried out except that potassium acetate was further blended in addition to 1 mmol of cuprous chloride and 3.7 mmol of sodium methoxide.

[Table] Examples 29 to 33 The same procedure as in Example 5 was carried out except that an alkali metal carboxylate was combined in addition to 1 mmol of cuprous chloride and 3.7 mmol of sodium methoxide. However, the reaction conditions are as follows. CO/H ₂ (molar ratio) = 1/1, reaction temperature 125°C,
Reaction pressure 60~80Kg/ ^cm2

【table】

Claims (1)

[Claims] 1. A method for synthesizing an oxygen-containing organic compound by reacting carbon monoxide and hydrogen, in which a copper compound other than copper oxide and at least one member selected from Na and K
A method characterized in that a catalyst comprising two alkali metal alkoxides is used. 2 The copper compound is copper alkoxide, copper allyl oxide, copper halide, copper carboxylate,
2. The method of synthesis according to claim 1, wherein the copper compound is selected from copper hydrides. 3. The synthesis method according to claim 1 or 2, wherein the alkali metal alkoxide is an alkali metal alkoxide of a linear alcohol. 4. The synthesis method according to any one of claims 1 to 3, wherein the alkali metal alkoxide is sodium alkoxide. 5. The synthesis method according to any one of claims 1 to 4, characterized in that the composition of the catalyst is an alkali metal alkoxide/copper compound molar ratio of 3 to 50. 6. The catalyst is a catalyst system in which a catalyst is mixed with a reaction medium, and 0.001 to 10 moles of a copper compound and 0.001 to 10 moles of an alkali metal alkoxide are blended with respect to reaction medium 1. A synthetic method according to any one of claims 1 to 5, characterized in that: 7. The synthesis method according to any one of claims 1 to 6, wherein the reaction temperature is 40 to 185°C, and the reaction pressure is 20 to 150 Kg/cm ² . 8 In a method of synthesizing an oxygen-containing organic compound by reacting carbon monoxide and hydrogen, a copper compound other than copper oxide and at least one selected from Na and K
1. A method for synthesizing an oxygen-containing organic compound, the method comprising using a catalyst comprising an alkali metal alkoxide and an alkali metal carboxylate. 9. The synthesis method according to claim 8, wherein the oxygen-containing organic compound is ethylene glycol. 10. The synthesis method according to claim 8 or 9, wherein the alkali metal carboxylate is potassium, rubidium or cesium carboxylate. 11. The synthesis method according to any one of claims 8 to 10, wherein the alkali metal carboxylate is an alkali metal acetate. 12. The synthesis according to any one of claims 8 to 11, characterized in that the proportion of the alkali metal carboxylate is 0.5 to 4 in molar ratio of alkali metal carboxylate/copper compound. Method. 13. The synthesis method according to any one of claims 8 to 12, wherein the reaction temperature is 85 to 140°C. 14 In a method for synthesizing an oxygen-containing organic compound by reacting carbon monoxide and hydrogen, a copper compound other than copper oxide, at least one alkali metal alkoxide selected from Na and K, and further magnesium, aluminum, titanium, and manganese. A method for synthesizing an oxygen-containing organic compound, the method comprising using a catalyst comprising at least one metal compound selected from: