JPH0411530B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for directly producing organic oxygen-containing compounds from a mixed gas of carbon monoxide and hydrogen (hereinafter referred to as synthesis gas). This invention relates to an improved method for selectively producing organic oxygen-containing compounds by a gas phase direct synthesis method. (Prior Art and Problems to be Solved by the Invention) Organic oxygen-containing compounds such as alcohols, aldehydes, fatty acids, and esters thereof are industrially useful substances as industrial chemicals and solvents. In particular, research into using alcohols alone or in combination with gasoline as automobile fuels is progressing in various countries, and the development of methods to directly produce these organic oxygenated compounds using synthetic gas as a raw material is actively progressing. It is being As a method for producing organic oxygen-containing compounds from synthesis gas using a solid-supported catalyst, a rhodium catalyst with a certain co-catalyst is already known (German Patent Application Publication No. 250233, Japanese Unexamined Patent Publication No. 51-80806, and Kaisho
52-14706). However, this catalyst has the disadvantage that it cannot be used in large quantities because its main component is rhodium, which is a rare and expensive resource on earth. Therefore, there is a need for the development of cheaper catalysts that do not use rhodium. Furthermore, it is known that inexpensive cobalt catalysts are effective in synthesis gas reactions; however, in this case, the main products are hydrocarbons and almost no organic oxygen-containing compounds are produced. Cobalt catalyst modified with copper, chromium, zinc, alkaline earth metals, aluminum, rare earths or iron (French patent no. 4122110)
and German Patent Application Publication No. 2748097) and cobalt catalysts modified with gold, silver, rhenium, etc. (European Patent No. 21330 and Japanese Patent Application Laid-open No. 56-25124), which can convert organic oxygen-containing compounds into synthesis gas reactions. However, these catalysts are very delicate in terms of manufacture and operation. Therefore, they generally require special and sophisticated techniques for catalyst preparation and operation, and the lifetime of the resulting catalyst is also short. Therefore, there is a need for the development of a robust and long-life catalyst that is easy to prepare and that produces organic oxygen-containing compounds from synthesis gas with high selectivity. (Means for Solving the Problems) The present inventors have conducted intensive research to overcome the drawbacks of the conventional catalysts mentioned above and develop a method for producing organic oxygen-containing compounds. By using a cobalt carbonyl compound as a cobalt component in a catalyst in which cobalt is supported on this catalyst, the selectivity of organic oxygen-containing compounds can be essentially increased, and by adding an alkaline earth element as a promoter, It was discovered that the compound selectivity was dramatically improved, and based on this finding, the present invention was completed. That is, the present invention is directed to the production of organic oxygen-containing compounds from synthesis gas containing carbon monoxide and hydrogen by a gas phase reaction, in which the reaction is carried out in the presence of a cobalt catalyst comprising a cobalt carbonyl compound supported on an oxide carrier. The present invention provides a method for producing an organic oxygen-containing compound, which is characterized by carrying out the following steps. The fact that organic oxygen-containing compounds can be synthesized with high selectivity using a catalyst with a simple composition as described above is truly surprising and unexpected. This is because the main products of conventional synthesis gas reactions over cobalt catalysts are hydrocarbons, and it has generally been thought that organic oxygen-containing compounds are not produced. The catalyst used in the present invention is obtained by supporting a cobalt carbonyl compound on an oxide that is a catalyst carrier, preferably an oxide supporting an alkaline earth element. Silica gel, alumina, titania, zirconia, niobium oxide, zeolite, etc. can be used as the oxide catalyst carrier. In the present invention, dicobalt octacarbonyl (Co ₂
(CO) ₈ ), tetracobalt dodecacarbonyl (Co ₄
(CO) ₁₂ ) etc. are used, and it can be supported on a support by the methods used when preparing ordinary solid supported catalysts, such as impregnation support method from a solution of cobalt carbonyl compound or gas phase mixing method. can. Further, alkaline earth elements used in the present invention include beryllium, magnesium, calcium, strontium, barium, radium, etc., and these are preferably acetates, oxalates, various organic acid salts, nitrates, carbonates, chlorides, etc. It is used as a material, etc., and is supported by ordinary impregnation and support methods. In carrying out the present invention, it is preferable to treat the catalyst in advance in a reducing atmosphere such as hydrogen. However, this treatment may be omitted and the reduction may be performed using synthesis gas. In the catalyst used in the present invention, the composition ratio of cobalt is preferably 1/1000 to 1000 parts by weight based on the weight of the carrier, and the alkaline earth element is preferably 1/100 to 30 parts by weight based on the amount of cobalt atoms. The molar ratio is more preferably 1/10 to 10 molar ratio. In the method of the present invention, reaction conditions other than the catalyst are not particularly different from conventional methods. For example, the reaction temperature is 150
The temperature is ~450°C and the space velocity is 1000~10000/h. The reaction pressure is 5 to 150 Kg/cm ² . The synthesis gas used in the present invention is not particularly limited, but the molar ratio of CO/H ₂ is usually 1/20 to 20/1, preferably 1/10 to 10/1. In addition to carbon monoxide and hydrogen, the raw material synthesis gas may also contain inert gases such as argon and nitrogen. The organic oxygen-containing compounds obtained by the method of the present invention have 1 to 10 carbon atoms, and examples of compounds having 2 carbon atoms include ethanol, acetaldehyde, acetic acid, and esters thereof. Each component can be separated from the product by a conventional distillation method or the like. (Effects of the Invention) According to the method of the present invention, organic oxygen-containing compounds can be obtained from synthesis gas with high selectivity, and the catalyst has an excellent effect of having a long life. (Examples) Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Example 1 Commercially available silica gel carrier (Davison #57, specific surface area
^Co n-hexane solution containing 1.45 g of ₂ (CO) ₈
The cobalt-silica catalyst (1) was obtained by immersing it in 50 ml of water and removing the solvent. Of this, 3 ml was filled into a fixed-bed high-pressure flow reactor (SUS316/glass double tube type, inner diameter 11 mm) in a nitrogen gas atmosphere, and after hydrogen treatment at 450°C for 3 hours, synthesis gas (carbon monoxide: hydrogen : Argon = 30:60:10, capacity ratio) at gauge pressure 21Kg/
cm ² and brought into contact with the catalyst at a space velocity of 2000/h. All the products were introduced into a gas chromatograph in a gaseous state and analyzed. Example 2 10 g of the same silica gel carrier as in Example 1 was immersed in 12 ml of an aqueous solution containing 4.41 g of magnesium acetate, and then dehydrated using a rotary evaporator.
After drying, magnesium-silica was obtained. Then,
This was treated with Co ₂ in a nitrogen gas atmosphere as in Example 1.
It was immersed in 50 ml of n-hexane solution containing 1.45 g of (CO) ₈ and the solvent was removed to obtain cobalt-magnesium-silica catalyst (2). Using this, pretreatment, reaction, and analysis were performed in the same manner as in Example 1. Example 3 10 g of the same silica gel carrier as in Example 1 was immersed in 12 ml of an aqueous solution containing 2.20 g of calcium acetate, then dehydrated using a rotary evaporator and dried to obtain calcium-silica. Next, this was treated with Co ₂ in a nitrogen gas atmosphere in the same manner as in Example 1.
It was immersed in 50 ml of n-hexane solution containing 1.45 g of (CO) ₈ and the solvent was removed to obtain cobalt-calcium-silica catalyst (3). Using this, pretreatment, reaction, and analysis were performed in the same manner as in Example 1. Example 4 10 g of the same silica gel carrier as in Example 1 was immersed in 12 ml of an aqueous solution containing 1.84 g of strontium acetate.
Then, it was dehydrated using a rotary evaporator and dried to obtain strontium-silica. Next, in the same manner as in Example 1, 50 ml of an n-hexane solution containing 1.45 g of Co ₂ (CO) ₈ was added under a nitrogen gas atmosphere.
The cobalt-strontium-silica catalyst (4) was obtained by immersing it in water and removing the solvent. Using this, pretreatment, reaction, and analysis were performed in the same manner as in Example 1. Example 5 10 g of the same silica gel carrier as in Example 1 was immersed in 50 ml of an aqueous solution containing 6.49 g of barium acetate, then dehydrated using a rotary evaporator and dried to obtain barium-silica. Next, this was treated with Co ₂ in a nitrogen gas atmosphere in the same manner as in Example 1.
It was immersed in 50 ml of n-hexane solution containing 1.45 g of (CO) ₈ and the solvent was removed to obtain cobalt-barium-silica catalyst (5). Using this, pretreatment, reaction, and analysis were performed in the same manner as in Example 1. Comparative Example 1 10 g of the same silica gel carrier as in Example 1 was immersed in 12 ml of an aqueous solution containing 2.11 g of cobalt acetate, then dehydrated using a rotary evaporator and dried to obtain cobalt-silica catalysts (6). Using this, pretreatment, reaction, and analysis were performed in the same manner as in Example 1. Comparative Example 2 10 g of the same silica gel carrier as in Example 1 was immersed in 12 ml of an aqueous solution containing 2.47 g of cobalt nitrate, then dehydrated using a rotary evaporator and dried to obtain cobalt-silica catalysts (7). Using this, pretreatment, reaction, and analysis were performed in the same manner as in Example 1. Comparative Example 3 10 g of the same silica gel carrier as in Example 1 was immersed in 12 ml of an aqueous solution containing 2.02 g of cobalt chloride, then dehydrated using a rotary evaporator and dried to obtain cobalt-silica catalysts (8). Using this, pretreatment, reaction, and analysis were performed in the same manner as in Example 1. Comparative Example 4 10 g of the same silica gel carrier as in Example 1 was immersed in 12 ml of an aqueous solution containing 1.23 g of strontium acetate.
Then, it was dehydrated using a rotary evaporator and dried to obtain strontium-silica. Next, this was added to cobalt acetate 2.11 in the same manner as in Comparative Example 1.
The cobalt-strontium-silica catalyst (9) was obtained by immersing the cobalt-strontium-silica catalyst (9) in 12 ml of an aqueous solution of g and removing the solvent. Using this, pretreatment, reaction, and analysis were performed in the same manner as in Example 1. The results of Examples and Comparative Examples conducted in this manner are shown in Table 1 below. Note that each code shown in Table 1 indicates the following. (a) In the catalyst section, the numbers in parentheses are the weight ratios of each component (cobalt and alkaline earth elements are converted into metals)
shows. (b) Carbon monoxide addition rate (%) = (supplied CO) mol - (unreacted CO) mol / (supplied CO) mol × 100 (c) Product carbon efficiency (%) (CO converted to each product ) mol/(Supplied CO) mol - (
(unreacted CO) mol x 100 (d) ΣC ₂ -O represents the sum of ethanol, acetaldehyde, acetic acid, and their esters. (e) ΣC ₁ −C ₈ OH indicates the sum of C ₁ to C ₈ alcohols. (f) C _o H _n indicates the sum of C ₁ to C ₂₀ hydrocarbons.

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Claims (1)

[Claims] 1. In the production of organic oxygen-containing compounds from synthesis gas containing carbon monoxide and hydrogen by gas phase reaction, in the presence of a cobalt catalyst comprising a cobalt carbonyl compound supported on an oxide carrier. A method for producing an organic oxygen-containing compound, which comprises carrying out a reaction. 2. The method according to claim 1, wherein the oxide carrier is silica gel. 3. The method according to claim 1, wherein the cobalt catalyst contains an alkaline earth element. 4. The method of claim 3, wherein the alkaline earth element is selected from magnesium, calcium, strontium and barium.