JP2701153B2 - Method for producing carbonyl compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention produces a carbonyl compound from olefin and water by a fuel cell system using an ion conductor provided with a catalyst electrode, and at the same time, extracts power energy as needed. About the method.

Aldehydes and ketones, which are carbonyl compounds, are important intermediates in the field of manufacturing organic industrial chemicals such as carboxylic acids and alcohols. For example, acetic acid, acetic anhydride, ketene, diketene, butanol, etc. are produced from acetaldehyde.

(Prior art) Carbonyl compounds such as ketones and aldehydes have been produced by methods such as dehydration of alcohols, hydration of acetylenes, oxidation of alkanes, and oxidation of olefins. Among them, the direct oxidation of olefins by the so-called Wacker method using a redox catalyst comprising palladium chloride and copper chloride is an industrially important method for producing carbonyl compounds. This method is industrially performed by blowing gaseous olefin and oxygen or air into a hydrochloric acid aqueous solution containing a catalytic amount of palladium chloride and a large excess of copper chloride using a reactor made of a high corrosion-resistant material such as titanium. However, a) Since the reaction is a homogeneous reaction, it is necessary to separate the product and the catalyst. b) Since hydrochloric acid is added to and reacted with a chloride catalyst such as palladium chloride or copper chloride, the reactor is highly corroded and a chlorine-containing compound is by-produced.
c) There is a problem that there is a danger of explosion because a mixed gas of olefin and oxygen is supplied as a reaction gas. Also, a method of obtaining a carbonyl compound by electrochemically oxidizing an olefin by applying a voltage to an electrode is known. However, a large amount of by-products such as carbon dioxide is generated, and the selectivity of a target product is low. Attempts have also been made recently to synthesize useful chemicals using a fuel cell system without applying voltage, but in this case too, it is difficult to control the reaction, and it is necessary to suppress complete combustion and selectively Not to get the object. For example
Electrochimica Acta.Vol.32 No.8 pp 1137-1143 (198
7) describes a method in which an aqueous solution of phosphoric acid is flowed between polybenzimidazole films, only propylene is flowed through one of the palladium electrodes provided on both sides, and oxygen is flowed through the other. The products obtained are acrolein, acrylic acid, carbon dioxide, etc., and almost no acetone is formed.

(Problems to be Solved by the Invention) The present invention selectively produces a corresponding carbonyl compound from olefins and water using a fuel cell system, thereby separating a product and a catalyst in a conventional production method, It solves problems such as corrosion, by-products of chlorine-containing compounds, and the danger of explosion due to mixing of olefin and oxygen.

(Means for Solving the Problems) The present invention uses a fuel cell system in which an olefin and water are brought into contact with one electrode of an ion conductor provided with a catalyst electrode and an oxidizing compound is brought into contact with the other electrode. In this method, the corresponding carbonyl compound is produced at a high selectivity and, at the same time, power energy is extracted as needed.

The olefin used in the method of the present invention is ethylene, propylene, butene or the like. From them, the corresponding carbonyl compounds, acetaldehyde, acetone and methyl ethyl ketone, are selectively obtained.

As the oxidizing compound used in the method of the present invention, any compound that can react with hydrogen on the catalyst of the method of the present invention can be used, but oxygen or air is generally used. Also, aldehydes, nitro compounds, aromatic compounds and other reducible compounds are supplied as oxidizing compounds, and carbonyl compounds are produced from olefins in the anode compartment, while a hydrogenation reaction is carried out in the cathode compartment, and alcohol, An amino compound, a saturated hydrocarbon compound and the like can be produced simultaneously.

In the method of the present invention, it is possible to extract energy corresponding to a change in free energy of the reaction from the reaction system as needed.

FIG. 1 shows a conceptual diagram of a fuel cell reactor for carrying out the method of the present invention.

An anode chamber having a positive electrode or a negative electrode formed of a catalyst electrode and a cathode chamber are separated by an ion conductor, and the positive electrode and the negative electrode are short-circuited by a lead wire. If necessary, a voltage can be applied between the positive electrode and the negative electrode.

As the catalyst electrode used in the method of the present invention, metals such as palladium and platinum or oxides thereof can be used, but in the method of the present invention, palladium is particularly preferred.

Examples of the solid ionic conductor used in the method of the present invention include a solid electrolyte known as a proton conductor such as heteropolyacid, H-mordenite, H-montmorillonite, and zirconium phosphate, and a perovskite-type solid solution based on SrCeO _3. Can be used. Further, one based on a fluorine-containing polymer such as perfluorocarbon, into which one or two kinds of cation exchange groups such as a sulfonic acid group or a carboxylic acid group are introduced, for example, Nafion (Du
Pout registered trademark) can also be used. As the solid ionic conductor used in the method of the present invention, phosphoric acid, sulfuric acid,
A solid material obtained by impregnating a liquid such as a protonic acid such as hydrochloric acid with a solid material such as silica wool may be used.

Olefin and water supplied as raw materials to the anode chamber are
It is usually a gas, but may be dissolved in an inert solvent or water and contacted with the electrode in a liquid phase if necessary. Further, the oxidizing compound supplied to the cathode chamber may be a gas or a liquid.

The reaction temperature is usually −20 to 200 ° C., particularly −5 to 150 ° C.
Is preferred.

The reaction is generally carried out at normal pressure, but may be carried out under increased or reduced pressure as necessary.

The reaction product may be either gaseous or liquid, but can be separated and purified by ordinary methods such as distillation to obtain a high-purity target product.

(Effects of the Invention) The method of the present invention is easier to separate a product and a catalyst because the reaction is a heterogeneous reaction as compared with the conventional production method by the Wacker method. b) Since no corrosive chloride is used, the reactor can be made inexpensive and simple. c) There are no by-products such as chlorine edible compounds. d) There is no danger of explosion because olefin and oxygen are separated and reacted. e) If necessary, energy can be extracted as electric power together with the product. Has many advantages such as:

(Examples) Hereinafter, the method of the present invention will be described specifically with reference to examples, but the reaction method and apparatus are illustrative, and the present invention is not limited to the examples.

Examples 1 to 5 Disc-shaped silica wool (1.0 mm thick, 21 mm diameter)
A 5% phosphoric acid aqueous solution containing 10 mg of palladium black on each side was placed in a reactor as shown in Fig. 1 as an ion conductor with electrodes, and ethylene, steam and helium were flowed into the anode chamber. 12: 1: 20ml / min
At a total of 33 ml / min, oxygen was supplied to the cathode chamber at 25 ml / min. There was no incorporation of bipolar gas through the septum. The product obtained from the anode compartment was analyzed by gas chromatography. Under closed circuit conditions (when no connection was made between the electrodes), only traces of carbon dioxide were generated, and when the circuit was closed, current flowed and acetaldehyde was selectively generated.
Table 1 shows the results 30 minutes after the start of the reaction when the reaction temperature was changed between 45 ° C and 122 ° C. Current efficiency is about 100
%, And the selectivity for acetaldehyde is 96% or more.

Examples 6 to 8 show the results when a voltage was applied between the electrodes to cause a reaction.
Are shown in Table 2 below. The reaction temperature was 83 ° C, and the other conditions were the same as in Example 1.

Example 9 Propylene using propylene instead of ethylene:
Water: The flow rate of helium is 4.6: 2.37.5 (ml / min), respectively.
The reaction was carried out in the same manner as in Example 1 except that the reaction was carried out at a reaction temperature of 95 ° C. As a result, if no voltage is applied to the electrodes, 7.
A current of 5 mA flowed and acetone was obtained at a rate of 0.12 × 10 ⁻⁶ mol / min. 13.2 mA when a voltage of 200 mV is applied to the electrode
And acetone was obtained at a rate of 1.43 × 10 ⁻⁶ mol / min.

[Brief description of the drawings]

FIG. 1 shows a conceptual diagram of a fuel cell type reactor used for carrying out the method of the present invention.

Claims (3)

(57) [Claims] 1. A reactor having a catalyst electrode containing palladium and / or platinum as a main component, and having a solid or solid ionic conductor between the two electrodes. A method for producing a carbonyl compound by a fuel cell system, wherein an oxidizing compound is brought into contact with the electrode. 2. The method according to claim 1, wherein the olefin is ethylene and the carbonyl compound is acetaldehyde. 3. The method according to claim 1, wherein the olefin is propylene and the carbonyl compound is acetone.