JPS59163335A - Gas phase oxidation method for olefins - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for gas phase oxidation of olefins. Specifically, when olefins are gas-phase oxidized with oxygen or oxygen-containing gas in the presence of water vapor to produce acetaldehyde or ketones, a supported catalyst in which palladium salts and vanadyl salts are supported on activated carbon is used as a catalyst. This is a gas phase oxidation method for olefins.

Conventionally, a method for producing acetaldehyde or ketones by oxidizing olefins with oxygen or an oxygen-containing gas in the presence of water using a palladium salt as a catalyst is known as the Varaker method. For example, when an olefin is oxidized with oxygen or an oxygen-containing gas in an aqueous hydrochloric acid solution containing palladium chloride and copper chloride, acetaldehyde or ketones are obtained. However, this liquid phase oxidation method has problems in terms of corrosion of the reactor and by-product of chlorine-containing compounds, and various countermeasures are required for industrial implementation. In particular, when an olefin with a carbon number of 4 or more is oxidized using a palladium chloride-copper chloride catalyst, a large amount of compounds such as chlorinated ketones are produced as by-products in addition to the corresponding ketone, so industrial implementation of the Varaka method is difficult. Limited to oxidation of ethylene and propylene.

Therefore, it has been desired to develop a solid catalyst that does not cause equipment corrosion, has few by-products, is easy to separate and purify products, and can be applied to a wide range of olefins.

For example, Industrial Chemistry Magazine Vol. 73, p. 2165 (1970)
, an activated carbon-supported palladium catalyst has been proposed;
This catalyst has low activity for the oxidation of olefins having 4 or more carbon atoms (problems in industrial implementation).
has proposed a catalyst in which palladium and vanadium pentoxide are supported on α-alumina, but this catalyst is extremely inactive for the oxidation of olefins having 4 or more carbon atoms.

The present inventor has conducted extensive research on carriers and co-catalyst components with the aim of designing a gas-phase Waraker catalyst that exhibits high activity even against olefins having 4 or more carbon atoms and produces fewer by-products. As a result, it was confirmed that a catalyst prepared by supporting a palladium salt and a vanadyl salt on an activated carbon carrier was a high-performance catalyst capable of achieving the above goals, and the present invention was completed.

The most important feature of the present invention is the use of activated carbon as a carrier and the use of vanadyl salt as a cocatalyst component that promotes the reoxidation of palladium. Even if a carrier other than activated carbon and a vanadium compound other than vanadyl salt are used as promoter components, the effects of the present invention cannot be obtained at all.

The activated carbon used as a catalyst carrier in the present invention is not particularly limited, and any known or commercially available carbon may be used as is, preferably after treatment with nitric acid or other activation treatment.

Further, the palladium salt and vanadyl salt used as catalyst components in the present invention are not particularly limited, and known ones can be used. Representative palladium salts suitably used include palladium chloride, palladium sulfate, palladium nitrate, palladium acetate, and the like. It is generally preferable to use palladium sulfate for the oxidation of olefins having 6 or more carbon atoms. Further, representative vanadyl salts suitably used include vanadyl sulfate, vanadyl nitrate, vanadyl sioate, and the like.

The method for supporting the catalyst component of the present invention on a carrier is not particularly limited, and any known method can be employed. A commonly used method is to dissolve a predetermined amount of palladium salt and vanadyl salt in an acidic aqueous solution such as dilute sulfuric acid or dilute hydrochloric acid, add a predetermined amount of activated carbon to the aqueous solution, and then add the predetermined amount of activated carbon to the aqueous solution.
The catalyst of the present invention is obtained by evaporating the water under normal pressure or reduced pressure while sufficiently stirring the mixture at a temperature below C for a necessary period of time, for example, about ω to 100 m, and drying in air or an inert gas.

In the catalyst of the present invention, the amount of palladium salt and vanadyl salt supported on activated carbon cannot be absolutely limited, but in general, the amount of palladium salt supported is 0.1 to 1 on activated carbon in terms of the palladium association name. 5% by weight is suitable, and the vanadyl salt has an atomic ratio (V
/pd) is preferably 2 to 20.

The reaction targeted by the method of the present invention is not particularly limited as long as it is a reaction in which olefins are oxidized in the gas phase with oxygen or an oxygen-containing gas in the presence of water vapor to synthesize acetaldehyde or ketones. The most commonly applied oxidation reactions are the production of acetaldehyde from ethylene, the production of acetone from propylene, the production of methyl ethyl ketone from 1-butene or 2-butene, and the production of cyclohexanone from cyclohexene. The method of the present invention can be applied under gas phase reaction conditions in a wide temperature range from low to high temperatures depending on the physical properties of the olefin to be oxidized, but generally 100 to 20
．． It is carried out at 0°C and 1 to 20 atm. The composition of the reaction raw materials consisting of olefin, oxygen or oxygen-containing gas, and water vapor is not particularly limited, but the reaction is generally carried out at a low oxygen partial pressure to maintain the upper explosive limit.

EXAMPLES In order to explain the present invention more specifically, Examples and Comparative Examples will be described below, but the present invention is not limited to these Examples.

Example 1 Commercially available activated carbon (manufactured by Kuraray Chemical Co., Ltd., GC) at 20 to 40
Grind it into pieces and add 10.0g of it to 100d of 1N nitric acid.
After heating under reflux for 3 hours, the cleaning solution reached a pH of 5,
Wash thoroughly with ion-exchanged water until it becomes 0.
It was air-dried for 5 hours and used as a catalyst carrier. 0.5N hydrochloric acid 10
After dissolving 9°4 x 10-5 moles of palladium chloride in d at room temperature, 2.0 g of the above dry activated carbon was added to this solution and stirred gently at room temperature for 5 hours to completely adsorb palladium chloride on the activated carbon. Then, the sample was thoroughly washed with ion-exchanged water until the pH of the washing solution reached 5.0. Ion exchange water 10
The above palladium chloride-supported activated carbon was added to an aqueous solution in which 9.6 x 10-' mol of vanadyl sulfate was dissolved in 1 and heated at 35°C under a reduced pressure of 20 mmHg with gentle stirring.
The water was removed by evaporation and air-dried at 60°C for 15 hours to obtain a supported catalyst. Catalyst 2.0 thus obtained
g was filled in the center of a Pyrex glass tube with an inner diameter of 1.5 cm and a length of 50 pots, and water vapor, ethylene, and oxygen were heated at 115°C at a rate of 41 m/min, 1011j, and 7rn1.g/min, respectively. I understood. The results were as shown in Table 1. The by-product was methyl ethyl ketone.

Furthermore, for comparison, a catalyst containing only palladium chloride and no vanadyl sulfate was prepared in the same manner as above, and the ethylene oxidation reaction was carried out in the same manner, and the results were as shown in Table 2. . The by-product was methyl ethyl ketone.

Table 1 Table 2 *Ethylene base yarn Example 2 Add 5.5% of 1N substitute acid to 7ml of ion exchange water. ON, 9.4 x 10 mol of palladium sulfate, and 9.6 x 1 [1-' mol] of vanadyl sulfate were added and completely dissolved at room temperature, and then added to this solution in the same manner as in Example 1. Obtained dry activated carbon carrier2. Add Og and stir gently 2.
Water was removed by evaporation at 35°C under a reduced pressure of 0 m7nHg, and
A supported catalyst was obtained by air drying at 0° C. for 15 hours. Catalyst 2 and DI thus obtained were packed into a reactor similar to that in Example 1, and water vapor, propylene and oxygen were passed through at 1,115° C. at a rate of 41 mJjQm7 and 7 ml per minute, respectively. Five hours after the reaction became steady, the conversion of propylene was 15%, and the selectivity of acetone based on glopylene was 97 molar.

Furthermore, for comparison, a propylene oxidation reaction was carried out in the same manner using a catalyst obtained in the same manner as above without using vanadyl sulfate, and the conversion rate of propylene after 5 hours when the reaction became steady. is 6.0% and the selectivity of acetone is 97
Example 3 2.0 g of a catalyst containing palladium sulfate and vanadyl sulfate obtained in the same manner as in Example 2 was charged into the same reactor as in Example 1, and steam was heated at 115°C. , 1-butene and oxygen were passed through at 41 ml/min, 10 #I/min and 7 ml/min, respectively. The conversion rate of 1-butene after 3 hours when the reaction was steady and busy was 14%, and the selectivity of methyl ethyl ketone based on 1-butene was 96 mole. By-products were nibutyl alcohol, biacetyl, acetic acid and acetaldehyde.

Furthermore, for comparison, a 1-butene oxidation reaction was performed in the same manner using a catalyst obtained by operating in the same manner as in Example 2 without using vanadyl sulfate. As a result, the conversion rate of 1-butene after 3 hours when the reaction became steady was 4.7%, and the selectivity of methyl ethyl ketone based on 1-butene was 94%. The by-product was mostly nibutyl alcohol.

Example 4 An oxidation reaction was carried out in the same manner as in Example 3 using 2.0 g of a catalyst containing palladium sulfate and vanadyl sulfate obtained in the same manner as in Example 2 and using cis-2-butene as the olefin. The conversion rate of cis-2-butene was 12% after 5 hours when the reaction became steady;
- The selectivity of methyl ethyl ketone based on butene was 96 mol.

Example 5 A catalyst 2.09 containing palladium sulfate and vanadyl sulfate obtained by operating in the same manner as in Example 2 was charged into a reactor similar to that in Example 1, and steam, cyclo-hexene gas and oxygen were heated at 120°C. 411 and j5yne per minute respectively
and 7 m1 passed. Six hours after the reaction became steady, the conversion rate of cyclohexane7/(n was 11 moles, and the selectivity of Schifte hexanone based on cyclohexene was 95 moles.

Example 6 A predetermined catalyst was obtained in the same manner as in Example 3, except that vanadyl oxalate was used instead of vanadyl sulfate, and then subjected to the reaction of 1-butene.

As a result, after 3 hours when the reaction became steady, the conversion rate of 1-butene was 13%, and the selectivity of methyl ethyl ketone was 96 mol.

Claims (1)

[Claims] A supported catalyst in which palladium salts and vanadyl salts are supported on activated carbon is used as a catalyst when olefins are gas-phase oxidized with oxygen or oxygen-containing gas in the presence of water vapor to produce acetaldehyde or ketones. A method for gas phase oxidation of olefins.