JP2704165B2 - Method for preparing catalyst for producing organic oxygenated compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention uses a mixed gas of carbon monoxide and hydrogen (hereinafter referred to as a synthesis gas) as a raw material and produces a C2 organic compound such as ethanol by a gas phase direct method. The present invention relates to a method for preparing a catalyst for selectively producing an oxygen-containing compound. More specifically, the present invention is for producing an organic oxygenated compound having 2 carbon atoms, such as ethanol, acetic acid, and acetaldehyde, in a high yield, in which cobalt, an alkali metal and a platinum group metal are supported on an oxide carrier. The present invention relates to a method for preparing a catalyst.

[Prior art] Alcohol, fatty acid, aldehyde, fatty acid ester,
In particular, organic oxygenated compounds having two carbon atoms, such as ethanol, acetic acid, and acetaldehyde, are widely used as industrial raw materials and solvents, and are important basic chemical products in the modern petrochemical industry. In addition, ethanol or ethyl acetate is expected to be used alone or as a mixture with gasoline as a non-polluting automobile fuel. Until now, these chemical products have been mainly manufactured using naphtha as a raw material. Considering the depletion of the world's petroleum resources, conversion to a method using synthetic gas as a raw material has been considered. Development is being actively promoted in each country.

As such a method, a method using a combination of a rhodium catalyst and a predetermined cocatalyst as a catalyst (German Patent Application Publication No. 250,233, JP-A-51-80805 and JP-A-52-14706) ) Is known, but rhodium is unsuitable for industrial practice because of its limited resources and difficult to obtain in large quantities. On the other hand, although a cobalt catalyst is known to be effective for a synthesis gas reaction, in many cases, the main component in the product is a hydrocarbon, and almost no oxygen-containing compound is generated. For this purpose, the cobalt catalyst may be modified with copper, chromium, zinc, alkaline earth metals, aluminum, rare earths or iron (French Patent No.
No. 4122110 and German Patent Application Publication No. 2748097) and modification with gold, silver, rhenium and the like (European Patent No.
21330 and JP-A-56-25125). However, these catalysts have drawbacks in that special conditions for preparation and use require special techniques, and the activity of the catalyst is insufficient and the life is short.

Thereafter, a catalyst in which iridium and cobalt or nickel are supported on an oxide carrier as active components (Japanese Patent Application Laid-Open No. 61-18073)
No. 3), a catalyst in which ruthenium, lithium, platinum, palladium, iron, cobalt, and at least one metal selected from the group consisting of nickel and nickel are supported on an oxide carrier as an active component (JP-A-60-161935) ), A method of producing an organic oxygen-containing compound from a synthesis gas at a high selectivity has been proposed, but it cannot be said that the catalyst activity and the life are sufficiently satisfactory.

[Problems to be Solved by the Invention] The present inventors have conducted various studies in order to overcome the drawbacks of catalysts used for producing organic oxygen compounds having 2 carbon atoms from synthesis gas. As a result, first, the carbonyl compound of cobalt is supported on an oxide carrier, and modified with an alkali metal or an alkaline earth metal,
They have found that the selectivity of oxygenates such as ethanol can be dramatically improved, and have proposed a method for producing oxygenates using this catalyst.

The catalyst used in this method is prepared by a method in which an active ingredient is supported on an oxide carrier in the form of a carbonyl compound, and then subjected to a reduction treatment with hydrogen to be converted into a metal form. Since the amount of the active ingredient that can be dispersed thereon is limited, it is not possible to sufficiently enhance the activity and the life.

An object of the present invention is to improve the activity and life of the conventional cobalt catalyst for producing an oxygen-containing compound without deteriorating the preferable characteristics of high selectivity.

[Means for Solving the Problems] The present inventors have conducted intensive studies on supporting an active ingredient such as cobalt or an alkali metal at a high concentration on an oxide carrier, and converted these into an organic carboxylate. Although the catalyst was successfully supported at a much higher concentration than when supported as a conventional carbonyl compound, when the catalyst thus supported was subjected to a hydrogen treatment, cobalt remained divalent as a carrier. It remains in an ultra-highly dispersed state on the top and shows little activity on the synthesis gas reaction ("Report from the Institute of Chemical Technology", vol. 84, p. 549). However, when a small amount of a compound of a platinum group metal such as iridium is added thereto and subjected to a reduction treatment with hydrogen, cobalt on the carrier is reduced to a metal state while maintaining a high dispersion state, and a high catalytic activity is obtained. As shown.

That is, the present invention relates to preparing a catalyst for selectively producing an organic oxygenated compound having 2 carbon atoms by a gas phase direct method using a mixed gas of carbon monoxide and hydrogen as a raw material.
After supporting cobalt and an alkali metal as organic carboxylate salts on the oxide carrier, respectively, reducing treatment with hydrogen, and then at least one metal selected from iridium, ruthenium, platinum, osmium, palladium and rhenium And then carrying out a reduction treatment with hydrogen after supporting the carbonyl compound.

As the oxide carrier used in the method of the present invention,
Silica gel is optimal, but alumina, titania, zirconia, niobium oxide, zeolite, magnesia and the like can also be used.

Next, acetic acid is preferred as the organic carboxylic acid that forms a salt with cobalt and an alkali metal, but propionic acid, citric acid, oxalic acid and the like may also be used.

Therefore, examples of the cobalt salt include cobalt acetate, cobalt propionate, cobalt citrate, and the like. Examples of the alkali metal salt include lithium, sodium, potassium, rubidium and cesium acetate and oxalic acid. Salts may be mentioned.

These cobalt salts and alkali metal salts are sequentially or simultaneously supported on an oxide carrier and then subjected to a reduction treatment with hydrogen. To support the cobalt salt and the alkali metal salt on a carrier, these salts are dissolved in water or another suitable solvent to form a solution, the carrier is immersed in the solution, and the solution is sufficiently impregnated into the carrier. It is convenient to remove the solvent and dry it.

The carrier thus obtained is then brought into contact with a carbonyl compound of at least one metal selected from iridium, ruthenium, platinum, osmium, palladium and rhenium to adsorb these carbonyl compounds. After that, it is again subjected to a reduction treatment with hydrogen. The contact at this time is advantageously performed by a gas phase mixing method.

The amount of the cobalt salt of the organic carboxylic acid used in the method of the present invention is 0.001 to 1 part by weight, preferably 0.01 to 0.1 part by weight, in terms of cobalt per 1 part by weight of the carrier, and the amount of the alkali metal salt of the organic carboxylic acid is cobalt atom. It is in the range of 100: 1 to 1:10, preferably in the range of 50: 1 to 1: 2, in terms of a molar ratio in terms of alkali metal with respect to. Also, iridium,
The used amount of the carbonyl compound of at least one metal selected from ruthenium, platinum, osmium and palladium is 100:
It ranges from 1 to 1: 2, preferably from 20: 1 to 2: 1.

In the method of the present invention, it is necessary to support a cobalt salt and an alkali metal salt on a carrier, or a metal carbonyl compound, and then perform a reduction treatment with hydrogen. It can be carried out by heating the support to 300 to 500 ° C. in a hydrogen atmosphere or a hydrogen stream. By this reduction treatment, the cobalt salt or the metal carbonyl compound supported on the carrier becomes
Each is converted to metal.

In order to carry out the synthesis gas reaction using the catalyst thus prepared, it is possible to carry out the reaction under the same conditions as in the prior art. For example, a reaction temperature of 150 to 450 ° C. and a reaction pressure of 5 to 15
It can be performed at 0 kg / cm ² and space velocity of 1000 to 20000 / h.
The composition of the synthesis gas at this time is not particularly limited, but is usually in a range of a molar ratio of carbon monoxide to hydrogen of 1:20 to 20: 1, preferably 1:10 to 10: 1. Further, in addition to carbon monoxide and hydrogen, an inert gas such as argon or nitrogen gas may be contained in the synthesis gas.

By the reaction of this synthesis gas, a mixture of methanol, ethanol, acetic acid and acetaldehyde is obtained,
When the catalyst prepared by the method of the present invention is used, the selectivity of ethanol can be significantly improved.

[Examples] Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1 Commercially available silica gel carrier (Fuji Davison # 57, specific surface area)
250~350m ² / g, a pore volume 0.95~1.2ml / g, an apparent specific gravity of 0.3
5 ~ 0.43g / 0.43) After exhausting 10g at 200 ℃ for 2 hours,
An aqueous solution containing 2.11 g of cobalt acetate and 0.51 g of lithium acetate
Immerse in 12 ml, stir well, dehydrate using a rotary evaporator, dry, and in a stream of hydrogen at 300 ° C for 3 hours.
To obtain a Co-Li / SiO ₂ of blue-violet and time processing. This was mixed with 0.3 g of iridium carbonyl (Ir ₄ (CO) ₁₂ ) powder (orange) and evacuated at 150 ° C. while stirring well to obtain a black Co—Ir—Li / SiO ₂ catalyst. The composition ratio of each component in this catalyst was 5: 2.1: 0.54: 100 (weight ratio).
After reducing this catalyst at 450 ° C. in a stream of hydrogen, 3 ml of this was packed in a fixed-bed flow high-pressure reactor (sus-316 / glass double tube type, 1 mm inner diameter) in a nitrogen gas atmosphere,
After 3 hours of hydrogen treatment at 21 ° C., a synthesis gas (carbon monoxide: hydrogen: argon = 30: 60: 10) with a gauge pressure of 21 kg / cm ² was introduced and brought into contact with the catalyst at a space velocity of 2000 / h. All of the products were introduced into a gas chromatograph and analyzed in a gaseous state. Table 1 shows the results of the synthesis gas reaction.

Example 2 10 g of the same silica gel carrier as in Example 1 was treated with cobalt acetate.
It was immersed in 12 ml of an aqueous solution containing 2.11 g and 0.34 g of sodium acetate, dehydrated, dried and hydrogen-treated as in Example 1 to obtain Co-Na
/ SiO ₂ was obtained. This was mixed with 0.3 g of iridium carbonyl powder in the same manner as in Example 1, and evacuated at 150 ° C. while stirring well to obtain a Co—Ir—Na / SiO ₂ catalyst.
The composition ratio of each component in this catalyst was 5: 2.1: 0.6: 100 (weight ratio). After reducing this catalyst in a hydrogen stream at 450 ° C., a synthesis gas reaction was carried out under the same conditions as in Example 1. Table 1 shows the results.

Example 3 10 g of the same silica gel carrier as in Example 1 was treated with cobalt acetate.
It was immersed in 12 ml of an aqueous solution containing 2.11 g and 0.37 g of potassium acetate, dehydrated, dried and hydrogen-treated as in Example 1 to obtain Co-K /
SiO ₂ was obtained. This was mixed with 0.3 g of iridium carbonyl powder in the same manner as in Example 1, and evacuated at 150 ° C. while stirring well to obtain a Co-Ir-K / SiO ₂ catalyst. The composition ratio of each component in this catalyst was 5: 2.1: 1.5: 100 (weight ratio). After reducing this catalyst in a hydrogen stream at 450 ° C., a synthesis gas reaction was carried out under the same conditions as in Example 1.
Table 1 shows the results.

Example 4 10 g of the same silica gel carrier as in Example 1 was
It was immersed in 12 ml of an aqueous solution containing 2.11 g and 0.36 g of rubidium acetate, and dehydrated, dried and hydrogenated as in Example 1 to obtain Co-Rb.
/ SiO ₂ was obtained. This was mixed with 0.3 g of iridium carbonyl powder in the same manner as in Example 1, and evacuated at 150 ° C. while stirring well to obtain a Co—Ir—Rb / SiO ₂ catalyst.
The composition ratio of each component in this catalyst was 5: 2.1: 2.2: 100 (weight ratio). After reducing this catalyst in a hydrogen stream at 450 ° C., a synthesis gas reaction was carried out under the same conditions as in Example 1. Table 1 shows the results.

Example 5 10 g of the same silica gel carrier as in Example 1 was added to cobalt acetate.
It was immersed in 12 ml of an aqueous solution containing 2.11 g and cesium acetate 0.49 g, and dehydrated, dried and hydrogen-treated as in Example 1 to obtain Co-Cs
/ SiO ₂ was obtained. This was mixed with 0.3 g of iridium carbonyl powder in the same manner as in Example 1 and evacuated at 150 ° C. while stirring well to obtain a Co—Ir—Cs / SiO ₂ catalyst.
The composition ratio of each component in this catalyst was 5: 2.1: 3.4: 100 (weight ratio). After reducing this catalyst in a hydrogen stream at 450 ° C., a synthesis gas reaction was carried out under the same conditions as in Example 1. Table 1 shows the results.

Comparative Example 1 10 g of the same silica gel carrier as in Example 1 was
It was immersed in 12 ml of an aqueous solution containing 2.11 g, dehydrated and dried in the same manner as in Example 1 to obtain Co / SiO ₂ . This catalyst is placed in a stream of hydrogen
After the reduction treatment at ℃, a synthesis gas reaction was carried out under the same conditions as in Example 1. Table 1 shows the results.

Comparative Example 2 0.3 g of iridium carbonyl powder was mixed with 10 g of the same silica gel carrier as in Example 1 and evacuated at 150 ° C. while stirring well to obtain an Ir / SiO ₂ catalyst. After reducing this catalyst in a hydrogen stream at 450 ° C., a synthesis gas reaction was carried out under the same conditions as in Example 1.
Table 1 shows the results.

Comparative Example 3 10 g of the same silica gel carrier as in Example 1 was
It was immersed in 12 ml of an aqueous solution containing 2.11 g, dehydrated, dried and hydrogen-treated in the same manner as in Example 1 to obtain Co / SiO ₂ . This was mixed with 0.3 g of iridium carbonyl powder in the same manner as in Example 1 and evacuated at 150 ° C. while stirring well to obtain Co-I
An r / SiO ₂ catalyst was obtained. After reducing this catalyst in a hydrogen stream at 450 ° C., a synthesis gas reaction was carried out under the same conditions as in Example 1. Table 1 shows the results.

 Each symbol shown in Table 1 indicates the following.

c) ΔC ₂ -O indicates the sum of ethanol, acetaldehyde, acetic acid and their esters.

d) ΣCO represents the sum of oxygen-containing compounds having 1 to 8 carbon atoms.

e) The hydrocarbon is the sum of hydrocarbons having 1 to 16 carbon atoms.

[Effects of the Invention] According to the method of the present invention, it is possible to obtain a catalyst for a reaction for producing an organic oxygenated compound having 2 carbon atoms from a synthesis gas having a high selectivity for ethanol, a high activity and a long life, from a synthesis gas. .

Continued on the front page (72) Inventor Kazuhiko Takeuchi 1-1-1, Higashi, Tsukuba, Ibaraki Pref., Institute of Chemical Technology, Industrial Technology Institute (72) Inventor Yoshihiro Sugi 1-1-1, Higashi, Higashi, Tsukuba, Ibaraki, Institute of Chemical Technology, Industrial Technology Institute

Claims (1)

(57) [Claims] 1. A catalyst for selectively producing an organic oxygenated compound having 2 carbon atoms by a gas phase direct method using a mixed gas of carbon monoxide and hydrogen as a raw material. Cobalt and alkali metal are each supported as an organic carboxylate, then reduced with hydrogen, and then loaded with a carbonyl compound of at least one metal selected from iridium, ruthenium, platinum, osmium, palladium and rhenium. A method for preparing a catalyst, which comprises subjecting the catalyst to a reduction treatment with hydrogen.