JP2947968B2 - Method for producing acetaldehyde - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION Acetaldehyde produces acetic acid, acetic anhydride, ketene, diketene, butanol and the like, and is widely used in organic solvents and the like, and is an extremely important intermediate in the manufacturing field of organic industrial chemicals. .

[0002] The present invention relates to a method for producing acetaldehyde from ethylene, water and an oxidizing compound by a fuel cell system using an ion conductor provided with a catalyst electrode, and at the same time extracting power energy as needed. More specifically, unlike a normal fuel cell system, ethylene, water, and oxidizable compounds are produced by a non-membrane fuel cell system in which the oxidizing side and the reducing side are not separated by a partition but are mixed with an oxidizing substance and a substance to be oxidized. And a method for producing acetaldehyde from the same.

[0003]

2. Description of the Related Art Acetaldehyde has been produced by a method such as dehydrogenation of alcohol, hydration of acetylene, oxidation of ethane and oxidation of ethylene. Among them, the direct oxidation method of ethylene by the so-called Wacker method using a redox catalyst comprising palladium chloride and copper chloride is an industrially important method for producing acetaldehyde. This method is industrially performed by blowing gaseous ethylene 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 chloride catalysts such as palladium chloride and copper chloride, the corrosion of the reactor is severe,
Chlorine-containing compounds are by-produced. There are problems such as.

There is also known a method in which a voltage is applied to an electrode to electrochemically oxidize an olefin to obtain a carbonyl compound such as an aldehyde or a ketone. Product selectivity is low. In addition, recently, attempts have been made to synthesize a useful chemical substance using a fuel cell system without applying a voltage. For example, Electrochemical Agent Act has been attempted.
a. Vol. 32 No8, pp1137-1143
(1987) describes a method in which an aqueous phosphoric acid solution is caused to flow between polybenzimidazole films, only propylene is allowed to flow to one of palladium electrodes provided on both sides thereof, and oxygen is caused to flow to the other. The resulting products are acrolein, acrylic acid, oxygen dioxide, etc., with little formation of acetone. An example of producing acetaldehyde from ethylene using a similar fuel cell system is disclosed in Japanese Patent Application No. 63-24 / 1994 filed by the present inventors.
6062 only. In this patent, both catalyst electrodes are separated by an ion conductor membrane and are manufactured by a diaphragm type fuel cell system in which ethylene and oxygen are not mixed, and the electrode chamber is separated by a diaphragm according to the present invention. In addition, a method using a non-diaphragm fuel cell system in which a reaction proceeds in a state where ethylene and oxygen or an oxidizing compound are mixed as a simple reactor has not been known so far.

[0005]

SUMMARY OF THE INVENTION The present invention provides a method for selectively producing acetaldehyde from ethylene and water using a fuel cell system. An object of the present invention is to solve problems such as by-products of a compound, and also to solve complicated reactors and forms such as a diaphragm which a conventional fuel cell system has.

[0006]

According to the present invention, as shown in FIG. 1, an electrode made of palladium metal and / or a palladium compound is provided on an ion conductive material as an electrode A.
Ruthenium, osmium, iridium,
An electrode made of at least one of rhodium and / or a compound of these metals is installed without both electrodes coming into contact with each other, and both electrodes are connected by a conductive wire or a conductive substance, and ethylene, water and This method involves contacting a mixture of oxygen or an oxidizing compound to produce acetaldehyde at a high selectivity using a non-diaphragm fuel cell system, and at the same time extracting power energy as needed. As the oxidizing compound used in the method of the present invention, any compound that can react with hydrogen on the catalyst electrode of the present invention can be used, but oxygen or air is generally used. If necessary, these can be used after being diluted with another medium. It is also possible to use a reducible compound as the oxidizing compound and simultaneously carry out a hydrogenation reaction.

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

The electrode A used in the method of the present invention is an electrode made of palladium and / or a palladium compound, and the electrode B is ruthenium, osmium,
An electrode made of iridium, rhodium and / or a compound of these metals. Examples of compounds of these metals include metal halides, metal nitrates, metal sulfates, metal oxides, metal phosphates, metal ammonium compounds, metal acetylacetones, metal acetates, metal carbonyl compounds, and the like. Of course, the method of the present invention is not limited to only these compounds. In preparing these electrodes, the above-mentioned metal and / or metal compound can be mixed or supported on a conductive substance, for example, graphite, activated carbon, carbon whisker or the like. Furthermore, when molding the electrode, various binders,
For example, it is also possible to mix Teflon or the like and heat-mold it before use. However, the method of the present invention is not limited only to these preparation methods and molding methods.

The ion conductor used in the method of the present invention is a solid known as a proton acid such as phosphoric acid, hydrochloric acid and sulfuric acid, a heteropolyacid, H-mordenite, H-montmorillonite and zirconium phosphate. An electrolyte, a perovskite-type solid solution containing SrCeO3 as a base, or the like can be used. Further, those based on a fluorine-containing polymer such as perfluorocarbon, into which one or two sulfonic acid groups or carboxylic acid groups are introduced, for example, Nafion (registered trademark of Du Pont)
Can also be used. A liquid such as phosphoric acid can be used by impregnating it with silica wool or the like, or can be used by sandwiching it between ion-permeable filters or membranes.

In the method of the present invention, the electrodes A and B are attached to these ionic conductors, but both electrodes are not brought into direct contact with each other, and these electrodes are connected by a conductive wire or an electrically conductive material. Do it. Thereby, electric energy is taken out from between the two electrodes to the outside and the reaction proceeds smoothly. The conductive wire or the electrically conductive substance used in the present invention is not particularly limited,
Any substance that can conduct electric current can be used, but gold, silver, and copper wires are recommended from the viewpoints of availability and high electrical conductivity.

Ethylene supplied in the process of the present invention,
Water and oxidizing compounds are usually gas or liquid,
If necessary, the catalyst may be dissolved in an inert medium (liquid or gas), diluted by mixing or the like, and brought into contact with the catalyst electrode.

The reaction temperature is usually from -20 ° C to 200 ° C, particularly preferably from -5 ° C to 150 ° C. Further, the reaction is generally carried out at normal pressure, but can be carried out under increased or reduced pressure as required. The reaction product can be separated and purified by ordinary methods such as distillation to obtain high-purity acetaldehyde.

[0013]

The present invention will be specifically described below with reference to examples. However, the reaction method and the reaction apparatus are illustrative, and the present invention is not limited to the examples. Example 1-4 Disk-shaped silica wool (thickness 1.0 mm, diameter 21
mm), an aqueous solution of 85% phosphoric acid was added thereto, and as shown in FIG. 1, 50 mg of graphite powder, 5 mg of Teflon powder and 20 mg of palladium black powder were thoroughly mixed as an electrode A on one of the disks, and then the sheet was hot-pressed. Then, 50 mg of graphite powder, 5 mg of Teflon powder, and 20 mg of ruthenium metal powder were molded and attached to the other electrode B in the same manner as the electrode A. After connecting the electrodes A and B with a gold wire, ethylene, oxygen, and water vapor were supplied at a reaction temperature of 40 ° C. to 100 ° C. by supplying a mixed gas of 16 ml / min, 4 ml / min, and 4.89 ml / min, respectively. Was subjected to a partial oxidation reaction.
As a result, as shown in Table 1, acetaldehyde was obtained in good yield, and at that time, generation of a high current was also recognized.

Comparative Example 1-4 The ethylene partial oxidation reaction was carried out under exactly the same conditions as in Example 1-4 except that the electrodes A and B were not connected. As a result, as shown in Table 1, the production of acetaldehyde was reduced. From these results, it can be seen that the present invention greatly contributes to the fuel cell system.

Example 5 The electrode B was made of 50 mg of graphite powder and 5 m of Teflon powder.
g and 20 mg of metal osmium powder were subjected to the partial oxidation reaction of ethylene under exactly the same conditions as in Example 3 except that the mixture was prepared by the same method as in Example 1-4. The results are shown in Table 1.

Comparative Example 5 A partial oxidation reaction of ethylene was carried out under the same conditions as in Example 5 except that the electrodes A and B were not connected with gold wires. As a result, as shown in Table 1, when the connection was not made, the generation rate of acetaldehyde was decreased. This also indicates that the present reaction is proceeding by the fuel cell system.

Example 6 Electrode B was made of 50 mg of graphite powder and 5 m of Teflon powder.
Example 3 except that a mixture of g and 20 mg of metal iridium powder was prepared and used in the same manner as in Example 1-4.
A partial oxidation reaction of ethylene was carried out under exactly the same conditions as described above.
The results are shown in Table 1.

Comparative Example 6 A partial oxidation reaction of ethylene was carried out under the same conditions as in Example 6 except that the electrodes A and B were not connected by a gold wire.
The results were compared with the case where the connection was made with a gold wire as shown in Table 1. The amount of acetaldehyde produced decreased.

Example 7 The electrode B was made of 50 mg of graphite powder and 5 m of Teflon powder.
g and a mixture of 20 mg of metal rhodium powder in Example 1
Example 3 except that it was prepared and used in the same manner as in Example-4.
The partial oxidation reaction of ethylene was performed under the same conditions as described above. As a result, as shown in Table 1, formation of acetaldehyde was observed in a favorable yield.

Comparative Example 7 A partial oxidation reaction of ethylene was carried out under the same conditions as in Example 7 except that the electrodes A and B were not connected with gold wires.
As shown in Table 1, the production amount of acetaldehyde was reduced.

Embodiments 8-10 The same electrodes and the like as those in Embodiments 1-4 were used, and all the same devices were used.
The raw material mixed gas is oxygen 2 ml / min, steam 4.89 ml
/ Min, and a total of 18 ml of ethylene + argon gas
/ Min, dilute ethylene with argon gas
The production reaction of acetaldehyde from ethylene was carried out under the same conditions as in Example 3 except that the concentration of ethylene introduced was changed. As shown in Table 2, the amount of acetaldehyde generated increased as the ethylene concentration was increased.

Comparative Example 8-10 Except that electrodes A and B were not connected by a conductor, all were held.
The partial oxidation reaction of ethylene was performed under the same conditions as in -10. As shown in Table 2, the amount of acetaldehyde produced clearly decreased.

Examples 11 to 13 Using the same apparatus as in Example 1-4, such as a catalyst electrode, etc., the raw material mixed gas was ethylene 14 ml / min, steam 4.89.
ml / min, and the sum of oxygen + argon gas is 6 ml / min.
Acetaldehyde was produced by a partial oxidation reaction of ethylene while changing the concentration of oxygen introduced so as to obtain the same conditions as in Example 3. Table 3 shows the results
As shown in Table 2, the amount of acetaldehyde produced increased with an increase in the oxygen introduction concentration. Comparative Examples 11-13 The partial oxidation reaction of ethylene was carried out under the same conditions as in Examples 11-13 except that the electrodes A and B were not connected with copper wires, but with different oxygen introduction concentrations. The results, as shown in Table 2, indicate that the amount of acetaldehyde produced was extremely lower than that in the case of connection, and that the reaction was proceeding in the fuel cell system.

Examples 14-16 The amounts of graphite and palladium were changed so that the total of 5 mg of Teflon, graphite powder + palladium black was 70 mg, and this was used as an electrode in the same manner as in Example 1-4. Example 3 except that it was used as electrode A
An ethylene oxidation reaction was carried out under the same conditions as described above. The results show that, as shown in Table 3, as the palladium content increases, the amount of acetaldehyde produced also increases.

Comparative Examples 14-16 Reactions were carried out under the same conditions as in Examples 14-16 except that the electrodes A and B were not connected by wires. Table 3 shows the results
As shown in the figure, the amount of acetaldehyde produced decreased.

Examples 17-19 The composition of ruthenium and graphite was changed so that the Teflon powder (5 mg) and the graphite powder + ruthenium powder were 70 mg, and an electrode B was prepared and used in the same manner as in Examples 1-4. The reaction was carried out under the same conditions as in Example 3 except that the reaction was performed. The results show that as shown in Table 4, the increase in the ruthenium content in the electrode B increases the amount of acetaldehyde generated.

Comparative Examples 17-19 Example 1 was repeated except that the electrodes A and B were not connected by conducting wires.
A partial oxidation reaction of ethylene was performed under the same conditions as in 7-19. As shown in Table 4, the amount of acetaldehyde produced hardly changed even when ruthenium was increased, and the reaction by the fuel cell system was improved by using the electrode B in which ruthenium was increased.

Examples 20-22 The production of acetaldehyde was carried out using the same apparatus and conditions as in Example 3 except that 200, 500 and 1000 millivolts were applied to the electrodes so that electrode A was the anode and electrode B was the cathode. The reaction was performed. As shown in Table 4, as shown in Table 4, the application of a voltage resulted in the generation of an extremely high acetaldehyde, and the application of a voltage in the method of the present invention is also an effective means.

[0029]

[Table 1] 温度 Temperature (℃) Current (mA) Acetaldehyde formation rate (Micromol / min) ─────────────────────────────────── Example 1 40 1.2 0. 51 Example 2 60 2.5 1.21 Example 3 80 4.6 2.17 Example 4 100 9.1 3.55 Comparative Example 1 40 --- 0.24 Comparative Example 2 60 ---- 0. 45 Comparative Example 3 80 --- 0.76 Comparative Example 4 100 --- 1.18 Example 5 80 1.8 1.37 Comparative Example 5 80 --- 0.89 Example 6 80 2.8 1. 85 Comparative Example 6 80 --- 1.15 Example 7 80 5.0 2.03 Comparative Example 7 80 --- 0.78 ── ─────────────

[0030]

[Table 2] ─────────────────────────────────── Flow rate (ml / min) Current Acetaldehyde generation Ethylene Argon Oxygen (mA) Rate (micromol / min) 例 Example 8 6 12 2 2.2 1.07 Example 9 11 7 2 2.4 1.34 Example 10 18 0 2 3.1 1.71 Comparative Example 8 6 12 2 --- 0.47 Comparative Example 9 11 7 2 −−− 0.67 Comparative Example 10 180 2 −−− 0.85 Example 11 144 4 2.4 1.24 Example 12 14 33 3 1.6 1.63 Example 13 14 16 4. 0 2.07 Comparative Example 11 14 42 −−− 0.54 Comparative Example 12 14 33 −−− 0.74 Comparative Example 13 14 16 −−− 0 90 ───────────────────────────────────

[0031]

[Table 3] 電極 Electrode A (mg) Electrode B (mg) Acetaldehyde Formation rate Pd: graphite Ru: degree of graphite (micromol / min) ─────────────────────────────────── Example 14 5:65 20:50 0.62 Example 15 30:40 20:50 2.86 Example 16 50:20 20:50 2.86 Comparative Example 14 5:65 20:50 0.15 Comparative Example 15 30:40 20:50 1.28 Comparative Example 16 50:20 20:50 1.62 Example 17 20:50 5:65 1.57 Example 18 20:50 25:45 2.57 Example 19 20 : 50 50:20 3.00 Comparative Example 17 20:50 5:65 0.88 Comparative Example 18 20:50 25:45 0.93 Comparative Example 19 20:50 50:20 0.83 ───────

[0032]

[Table 4] ─────────────────────────────────── Applied voltage Acetaldehyde generation rate (mV) (micromol / Min) 例 Example 20 200 2.73 Example 21 500 7 .50 Example 22 1000 15.12

[0033]

According to the method of the present invention, a) the reaction is a heterogeneous reaction as compared with the conventional production method by the Wacker method, so that the product and the catalyst can be easily separated. b) Since no corrosive chloride is used, the reactor can be made inexpensive and simple.
c) There are no by-products such as chlorinated products. d) Compared to conventional fuel cell reactors, no diaphragm is required, resulting in a simpler structure and easier operation. f) If necessary, energy can be extracted as electric power together with the product. Has many advantages such as:

[Brief description of the drawings]

 FIG. 1 is a schematic diagram of a non-diaphragm fuel cell system.

FIG. 1 is a schematic diagram of a non-diaphragm fuel cell system.

[Explanation of symbols]

 Reference Signs List 1 electrode A 2 electrode B 3 ion conductive material 4 conductive material 5 ammeter 6 voltmeter

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B01J 27/25 B01J 27/25 X 31/04 31/04 X 31/12 31/12 X C07C 45/28 C07C 45/28 C25B 5/00 C25B 5/00 H01M 8/06 H01M 8/06 R // C07B 61/00 300 C07B 61/00 300

Claims (3)

(57) [Claims] 1. An electrode made of a palladium metal and / or a palladium compound as an electrode A, and ruthenium, osmium, iridium, rhodium and at least one of these metal compounds as an electrode B on an ion conductor material.
At least two kinds of electrodes are attached so that both electrodes do not come into direct contact with each other, and both electrodes are connected by a conductive wire or a conductive material, and a mixture of ethylene, water and an oxidizing compound is brought into contact with the electrodes. Acetaldehyde production method using a non-diaphragm fuel cell system. 2. The method according to claim 1, wherein a voltage is applied to both electrodes. 3. The metal compound is at least one compound selected from metal halides, metal nitrates, metal sulfates, metal oxides, metal hydroxides, metal phosphates and metal ammonium salts. 2. The method according to 1.