JP2000334301A - Production of catalyst for synthesizing acetaldehyde - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalyst for producing acetaldehyde from methyl acetate, carbon monoxide and hydrogen in a high yield with high selectivity. SOLUTION: A catalyst is produced by treating a compsn., which consists of rhodium and/or a rhodium compd. and palladium and/or a palladium compd., or a compsn., which consists of rhodium and/or a rhodium compd., palladium and/or a palladium compd. and alkali halide and/or alkaline earth metal halide, with an organohalogen compd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an acetaldehyde synthesis catalyst and a method for activating the catalyst.
More specifically, the present invention relates to a method for producing a catalyst used in producing methyl acetaldehyde by reacting methyl acetate with carbon monoxide and hydrogen in a gaseous phase and an activation method. Acetaldehyde is an intermediate such as ethyl acetate, pyridine, and ethylamine, and is a very industrially useful compound.

[0002]

2. Description of the Related Art Acetaldehyde is conventionally produced by the Wacker oxidation of ethylene with oxygen, and there are two methods, a one-step method and a two-step method, using a water-soluble catalyst system of palladium chloride, copper chloride and hydrochloric acid. Has been put to practical use. In the Wacker method, a high chloride ion concentration and a large amount of copper chloride are required, so that the apparatus is highly corrosive, and it is necessary to use a material such as titanium which is practically expensive. Further, since chlorine-based by-products are generated, it is necessary to appropriately separate and dispose of the by-products, and there is a problem of cost.

Under the influence of the raw material circumstances, as a method not using ethylene, (1) a reaction between acetic anhydride and hydrogen at normal temperature, normal pressure and liquid phase using a platinum oxide catalyst or a metal palladium catalyst supported on barium sulfate. (Chem. Ber., 95,
1844 (1962)), (2) A method of producing from acetic anhydride and synthesis gas using a cobalt carbonyl catalyst (Japanese Patent Publication No. 48-19285), (3) Using a rhodium chloride catalyst in the presence of triphenylphosphine Hydrogenation of acetic anhydride at 100-200 ° C. under liquid phase pressure to produce (US Pat.
No. 3579566). In the case of these methods, industrialization is considered difficult because the yield and selectivity of acetaldehyde are very low. Also, in (4) a synthesis method from methyl acetate, carbon monoxide and hydrogen using a catalyst supporting a rhodium compound and a palladium compound (Japanese Patent Publication No.
-37092), the reaction rate of methyl acetate is about 5%, and the selectivity of acetaldehyde is about 88%, which is a low value of the yield of acetaldehyde.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to selectively react acetaldehyde in a gas phase by reacting methyl acetate with carbon monoxide and hydrogen in a gas phase. It is an object of the present invention to provide a method for producing a catalyst produced at a high rate and a method for activating an acetaldehyde synthesis catalyst.

[0005]

Means for Solving the Problems The present inventors have made a carrier comprising a composition comprising rhodium and / or a rhodium compound, palladium and / or a palladium compound and an alkali metal halide and / or an alkaline earth metal halide. By treating with an organic halogen compound after loading, it has been found that acetaldehyde can be produced selectively and in high yield from methyl acetate, carbon monoxide and hydrogen by a gas phase contact reaction, and the present invention has been achieved. That is, the present invention provides (1) a composition comprising rhodium and / or a rhodium compound and palladium and / or a palladium compound, or a rhodium and / or rhodium compound and palladium and / or a palladium compound and an alkali metal halide and / or a halogen. A method for producing an acetaldehyde synthesis catalyst comprising treating a composition comprising an alkaline earth metal with an organic halogen compound, and (2) a catalyst comprising rhodium and / or a rhodium compound and palladium and / or a palladium compound, or rhodium and / or Alternatively, the present invention relates to a method for activating an acetaldehyde synthesis catalyst in which a catalyst comprising a rhodium compound and palladium and / or a palladium compound and an alkali metal halide and / or an alkaline earth metal halide is treated with an organic halogen compound.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A method for producing an acetaldehyde synthesis catalyst according to the present invention will be described below. Usually, in the method for producing an acetaldehyde synthesis catalyst of the present invention, an alkali metal halide and / or an alkaline earth metal halide comprising rhodium and / or a rhodium compound and palladium and / or a palladium compound, if necessary, is further added. It is preferable to treat the composition with an organic halogen compound after supporting the composition on a carrier. However, the composition may be supported on a carrier after treating with an organic halogen compound.

Specific examples of the rhodium compound used as a raw material of the catalyst of the present invention include rhodium trichloride, rhodium hexamine chloride, rhodium ammonium hexachloride, rhodium acetate, and rhodium nitrate. Ammonium palladium chloride,
Palladium acetate, dichlorotetramine palladium, palladium nitrate and the like can be mentioned. Preferred as alkali metal halides and alkaline earth metal halides are alkali metal halides such as lithium, sodium and potassium and alkali earth metal halides such as magnesium, calcium and strontium. These may be used alone or in combination of two or more.

Rhodium, rhodium compound, palladium,
The palladium compound, alkali metal halide and alkaline earth metal halide are usually supported on a carrier. Examples of the carrier include activated carbon, alumina, silica, silica-alumina, zirconia, titania and the like. Preferably, activated carbon or zirconia can be used.
Rhodium, a rhodium compound, palladium, a palladium compound, an alkali metal halide and an alkali earth metal halide carried on a carrier in an amount of 0.
It is 1 to 10% by weight, preferably 0.5 to 5% by weight. The ratio of rhodium and / or rhodium compound to palladium and / or palladium compound to alkali metal halide or alkali earth metal halide may be any value, and can be freely adjusted within this range. The method of supporting rhodium, a rhodium compound, palladium, a palladium compound, an alkali metal halide and an alkaline earth metal halide on a carrier is carried out by a generally known method, for example, by impregnation.

[0009] Rhodium, a rhodium compound, palladium, a palladium compound, an alkali metal halide and an alkaline earth metal halide supported on a carrier are treated with an organic halogen compound. Preferred as organic halogen compounds are methyl iodide, methyl bromide, acetyl iodide, acetyl bromide, and the like, with iodide being particularly preferred. The organic halogen compounds may be used alone or in combination of two or more. The method of treating with an organic halogen compound may be any method. For example, an organic halogen compound or a solution containing an organic halogen compound may be brought into contact with a catalyst. When the organic halogen compound is used by dissolving it in a solvent, the solvent is preferably one that does not adversely affect the catalyst and the reaction, and is preferably methanol, ethanol, acetone, or toluene. Specifically, before the catalyst is filled, the contact may be performed by a batch method, or after the filling, the organic halogen compound-containing solution may be supplied to and contacted with the catalyst by a continuous method instead of the raw material instead of the raw material. . The amount of the organic halogen compound used in the treatment of the catalyst is 0.5 to 5 times, preferably 1 to 5 times the weight of the catalyst.
It is twice. The temperature of the organic halogen compound treatment may be room temperature or higher, and the pressure may be normal pressure or higher.

When the treatment with an organic halogen compound is carried out by a batch method, the above-mentioned amount of the organic halogen compound is added to the catalyst, brought into contact with the catalyst, air-dried, and then filled with the catalyst. The contact time is at least 1 minute, preferably at least 5 minutes. In addition, in the case of performing the continuous method, the above amount of the organic halogen compound may be added to and brought into contact with the catalyst. At this time, a gas may be entrained, and the gas may be a carbon monoxide / hydrogen mixed gas used for the reaction, nitrogen,
An inert gas such as helium or argon may be used. The amount of entrained gas may be about the same as during the reaction, and is 1000 to 3000 h ^{-1 in} GHSV.
Is fine. The supply of the organic halogen compound may be carried out in 10 minutes or more, preferably in 0.5 to 2 hours. Before the reaction or treatment with an organic halogen compound, heat treatment may be performed under a stream of an inert gas such as nitrogen, helium, or argon, or reduction may be performed at 100 to 400 ° C. under a stream of carbon monoxide or hydrogen. Is also good.

Hereinafter, the method for activating the acetaldehyde synthesis catalyst of the present invention will be described. In the method for activating the acetaldehyde synthesis catalyst of the present invention, an alkali metal halide and / or an alkaline earth metal halide comprising rhodium and / or a rhodium compound and palladium and / or a palladium compound may be further added. A catalyst having the composition supported on a carrier is treated with an organic halogen compound. The acetaldehyde synthesis catalyst to be subjected to the activation method of the present invention is used or has insufficient catalytic activity during use. The activation method is the same as the above-described method for treating an acetaldehyde synthesis catalyst of the present invention with an organic halogen compound. Hereinafter, using the catalyst obtained by the method for producing an acetaldehyde synthesis catalyst of the present invention or the method for activating the acetaldehyde synthesis catalyst of the present invention,
A method for producing acetaldehyde from methyl acetate, carbon monoxide and hydrogen will be described.

When acetaldehyde is produced using the catalyst of the present invention, a cocatalyst is required. Halogen compounds used as cocatalysts are iodides, chlorides, bromides and the like, for example, methyl iodide, methyl bromide, acetyl iodide, acetyl bromide and the like. These may be used alone or in combination of two or more. In the reaction of the present invention, methyl acetate, a co-catalyst and hydrogen,
What is necessary is just to flow carbon monoxide and make it react on the said catalyst.
At this time, the reaction can be performed even in the presence of an inert gas such as nitrogen. The ratio of hydrogen to carbon monoxide is 0.1 to 10, preferably 0.25 to 4, in molar ratio (hydrogen / carbon monoxide). The gas amount is 5000 h ⁻¹ or less in GHSV, preferably
The reaction is carried out at 1000-3000 h ^-1 . The raw material methyl acetate and the co-catalyst halogen compound can be supplied separately,
You may supply by mixing. The proportion of the halogen compound in the supply amount (methyl acetate + promoter) is 10 to 50% by weight, preferably 20 to 40% by weight. The reaction is carried out at a supply amount of 10 h ^-1 or less, preferably 5 h ^-1 or less, using WHSV.

The reaction can be carried out under any reaction pressure. However, if the reaction pressure is too high, a liquid phase is likely to be formed on the catalyst. Therefore, it is desirable to carry out the reaction under a relatively low pressure. Generally, 10 MPa or less, preferably 2 MPa or more and 6 MPa or less.
Perform at or below MPa. The reaction temperature is preferably higher than the temperature at which the supplied methyl acetate or cocatalyst is vaporized, and is generally 100 to 3
The reaction is carried out at 00 ° C, preferably at 150-250 ° C. Next, the method of the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the scope of the present invention is not limited by these examples.

[0014]

EXAMPLES Comparative Example 1 Granular activated carbon (Kuraray Chemical Co., Kuraray Coal GC, 10-
32 mesh) is immersed in an aqueous hydrochloric acid solution of palladium chloride and rhodium chloride trihydrate, and the granular activated carbon is separated and dried by an evaporator. A catalyst impregnated and supported on granular activated carbon was prepared. This catalyst was heat-treated at 400 ° C. for 3 hours under a nitrogen stream, and then charged into a zirconium reactor. 2mm diameter above and below the catalyst
The catalyst was fixed by filling a porcelain Raschig ring of φ, height 2 mm. In the reaction, 4 MPa, 200 ° C., a hydrogen / carbon monoxide mixed gas (50/50 mol%) was supplied to the reactor at a rate of GHSV = 3000 h ⁻¹ , and a methyl acetate / methyl iodide mixed solution (80/20 wt.
%), And then supplied to the reactor at a rate of WHSV = 2 h ^-1 . The gas after the reaction was cooled, and the obtained product liquid and generated gas were analyzed by gas chromatography.

As a result, acetaldehyde and acetic acid were obtained as main components. The reaction results are as follows. In the reaction results, selectivity refers to the percentage of the moles of each product to the moles of methyl acetate utilized. Conversion rate of raw material methyl acetate is 13%. Selectivity for acetaldehyde 86% Selectivity for paraaldehyde (trimer of acetaldehyde)
5% Selectivity for acetic acid 103% Selectivity for methane 0.7% Selectivity for ethylidene diacetate 0%

Example 1 An impregnated supported catalyst obtained in the same manner as in Comparative Example 1 was treated under a nitrogen stream.
After heat treatment at 00 ° C. for 3 hours, methyl iodide of the same weight as the catalyst cooled to room temperature was added to the catalyst, and the mixture was stirred for 10 minutes and evaporated to dryness. Thereafter, a zirconium-made reactor was charged with a methyl iodide-treated catalyst in the same manner as in Comparative Example 1, and
The reaction was performed under the same conditions. As a result, the conversion of the raw material methyl acetate was improved as compared with the catalyst not pretreated with methyl iodide, and acetaldehyde and acetic acid were obtained as main components. The reaction results are as follows. Conversion rate of raw material methyl acetate 22% Selectivity of acetaldehyde 91% Selectivity of paraaldehyde (trimer of acetaldehyde)
6% Selectivity for acetic acid 100% Selectivity for methane 1% Selectivity for ethylidene diacetate 0.4%

Example 2 The catalyst after the reaction of Comparative Example 1 was charged into a reactor at 6 MPa, 200 ° C., and a hydrogen / carbon monoxide mixed gas (50%).
/ 50 mol%) at a rate of GHSV = 3000 h ⁻¹ , methyl iodide of the same weight as the catalyst was supplied over 1 hour to treat the catalyst. Thereafter, the reaction was performed under the same conditions as in Comparative Example 1. As a result, the conversion of the raw material methyl acetate was improved as compared with the catalyst not pretreated with methyl iodide, and acetaldehyde and acetic acid were obtained as main components. The reaction results are as follows. Conversion rate of raw material methyl acetate 19% Selectivity of acetaldehyde 94% Selectivity of paraaldehyde (trimer of acetaldehyde)
3% Selectivity for acetic acid 100% Selectivity for methane 0% Selectivity for ethylidene diacetate 0.5%

Comparative Example 2 Granular activated carbon (Kuraray Chemical Co., Kuraray Coal GC, 10-
32 mesh) palladium chloride, rhodium chloride trihydrate
And immersed in an aqueous solution of lithium chloride and hydrochloric acid.
Separated charcoal, dried by evaporator, and 1
wt% palladium chloride equivalent, 1wt% rhodium chloride equivalent
Trihydrate and 0.5% lithium chloride equivalent to granular activated carbon
An impregnated supported catalyst was prepared. Put this catalyst under a stream of nitrogen
 After heat treatment at 400 ℃ for 3 hours, it is made of zirconium
The reactor was charged. Above and below the catalyst, diameter 2mmφ, height
A 2 mm porcelain Raschig ring was filled to fix the catalyst.
The reaction is performed at 4MPa, 200 ℃, hydrogen / carbon monoxide mixed gas (50
/ 50mol%) GHSV = 3000h ^-1To the reactor at the rate of
A mixture of methyl acetate / methyl iodide (80 / 20wt%)
WHSV = 4h^-1To the reactor at a rate of
Was performed. After the reaction, the gas is cooled and the resulting product liquid
And product gas are analyzed by gas chromatography.
Was. As a result, acetaldehyde and acetic acid are the main components
I got it. The reaction results are as follows. Conversion rate of raw material methyl acetate 15% Selectivity of acetaldehyde 95% Selectivity of paraaldehyde (trimer of acetaldehyde)
 0% Selectivity for acetic acid 100% Selectivity for methane 1% Selectivity for ethylidene diacetate 1%

Example 3 In the same manner as in Comparative Example 2, a catalyst in which 0.5% of lithium chloride was impregnated and supported as a metal was prepared. The catalyst was heat-treated at 400 ° C. for 3 hours under a nitrogen stream, and then methyl iodide of the same weight as the catalyst cooled to room temperature was added to the catalyst.
Stir for 10 minutes and evaporate to dryness. Thereafter, the catalyst treated with methyl iodide was charged into a reactor made of zirconium in the same manner as in Comparative Example 2, and the reaction was carried out under the same conditions. As a result, the conversion of the raw material methyl acetate was improved as compared with the catalyst not pretreated with methyl iodide, and acetaldehyde and acetic acid were obtained as main components. The reaction results are as follows. Conversion rate of raw material methyl acetate 22% Selectivity of acetaldehyde 96% Selectivity of paraaldehyde (trimer of acetaldehyde)
2% Selectivity for acetic acid 100% Selectivity for methane 1% Selectivity for ethylidene diacetate 1%

[0020]

By using the catalyst obtained by the method for producing an acetaldehyde synthesis catalyst of the present invention or the method for activating the acetaldehyde synthesis catalyst of the present invention, acetaldehyde can be produced in a high yield from methanol, carbon monoxide and hydrogen. Can be manufactured with high selectivity.

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[Procedure amendment]

[Submission date] June 2, 1999 (1999.6.2)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction contents]

[0020]

EFFECT OF THE INVENTION By using the catalyst obtained by the method for producing the acetaldehyde synthesis catalyst of the present invention or the method for activating the acetaldehyde synthesis catalyst of the present invention, acetate acetate
Acetaldehyde can be produced with high yield and high selectivity from chill , carbon monoxide and hydrogen.

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Claims (4)

[Claims] 1. A composition comprising rhodium and / or a rhodium compound and palladium and / or a palladium compound, or a rhodium and / or rhodium compound and palladium and / or a palladium compound and an alkali metal halide and / or an alkaline earth halide. A method for producing an acetaldehyde synthesis catalyst, comprising treating a composition comprising a class of metals with an organic halogen compound. 2. A catalyst comprising rhodium and / or a rhodium compound and palladium and / or a palladium compound,
Alternatively, activation of an acetaldehyde synthesis catalyst characterized in that a catalyst comprising rhodium and / or a rhodium compound and palladium and / or a palladium compound and an alkali metal halide and / or an alkaline earth metal halide is treated with an organic halogen compound. Law. 3. A process for producing acetaldehyde, which comprises reacting methyl acetate with carbon monoxide and hydrogen in the gas phase in the presence of the catalyst obtained by the process according to claim 1 to produce acetaldehyde. 4. A process for producing acetaldehyde, comprising reacting methyl acetate with carbon monoxide and hydrogen in the gas phase in the presence of a catalyst obtained by the activation method according to claim 2 to produce acetaldehyde. .