JPS62292738A - Production of phenol - Google Patents

Abstract

PURPOSE:To safely and economically improve the selectivity under mild condition of low temperature and pressures, by directly oxidizing benzene in the presence of a specific catalyst in the presence of 1,10-phenanthroline and carbon monoxide to give the titled compound. CONSTITUTION:Benzene is oxidized with, preferably oxygen gas as an oxidizing agent in the presence of a palladium based catalyst, 1,10-phenanthroline and carbon monoxide, normally at 120-250 deg.C, preferably 150-220 deg.C under 5-30kg/ cm<2>G, preferably 7-25kg/cm<2>G pressure to afford the aimed compound. Palladium black and palladium carbon are preferred for the palladium based catalyst. The amount of the catalyst used is 0.05-30.0g atoms, particularly 0.30-3.00g atoms expressed in terms of palladium metal based on 1mol banzene. The amount of the 1,10-phenanthroline used is preferably 0.5-2.0mol based on the palladium metal atom.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for producing phenol, and more specifically, a method for directly oxidizing benzene using a specific catalyst and additives. This invention relates to a method for producing phenol.

[Prior art and its problems] Conventionally, as a method for producing phenol by direct oxidation of benzene, a method of oxidizing with nitrogen or carbon monoxide using an oxide of vanadium, molybdenum, tungsten, or chromium as a catalyst has been conventionally used. JP-A-513-148522) A method of oxidizing with hydrocarbon oxide using a molybdenum catalyst such as MoO3 or MoC12 is known (JP-A-58-210038).

However, in the former method, the reaction temperature was set at 45
There are problems in that the temperature must be raised to a high temperature of 0 to 650°C, and that a highly reactive oxygen anion radical generator such as nitrogen monoxide is required as an oxidizing agent. On the other hand, the latter method, although the reaction conditions are mild, uses organic-JS oxides that are highly dangerous such as explosions, and has many problems such as handling and countermeasures for the reaction equipment. .

[Purpose of IJI] This IJ+ is based on the above-mentioned sentient beings.

That is, one object of the present invention is to provide a method for producing phenol by direct oxidation of benzene, which overcomes the above-mentioned problems.

[Means for achieving the above object] The gist of the present invention for achieving the above object is characterized in that benzene is oxidized in the presence of 1,10-phenanthroline and carbon monoxide using a palladium-based catalyst. This is a method for producing phenol.

The benzene is most preferably pure, but crude benzene obtained from various processes such as petroleum reforming process and catalytic cracking process, recovered benzene, etc. can also be used.

The carbon oxide is most preferably pure, but carbon monoxide-containing gases obtained from water gas, generator gas, coke oven gas, etc. can also be used.

The palladium-based catalysts include palladium black catalyst, colloidal palladium catalyst, palladium bisacetylacetonate catalyst, palladium chloride, palladium acetate, palladium oxide catalyst, palladium hydroxide catalyst, palladium carbon catalyst, palladium hydroxide carbon catalyst, palladium barium sulfate. Examples include catalysts, palladium calcium carbonate catalysts, and other supported palladium catalysts.

Among these various palladium catalysts, palladium black and palladium carbon are preferred.

The amount of palladium component supported on palladium carbon is usually 1 to 20% by weight, preferably 2 to 15% by weight as palladium metal.

The palladium black can be prepared, for example, by reducing an aqueous solution of palladium chloride with molecular hydrogen, formalin, and an alkali.

In addition, methods such as reducing palladium chloride with hydrogen gas in an unsaturated organic compound, reducing an ammonia aqueous solution of palladium chloride with formic acid in an alkaline state, and dissolving palladium metal in aqua regia and treating it with sodium formate can also be used. It can be prepared.

Examples of the form of the palladium component in the palladium carbon or palladium black that can be suitably used as the catalyst as is include highly dispersed metallic palladium and a palladium component that can be converted into this by the reaction.

As the carbon supporting palladium, mention may be made of amorphous carbon, graphite and mixtures thereof.

Among these, ultrafine graphite particles or aggregates thereof, and amorphous carbon are preferable, and amorphous carbon can be particularly preferably used.

Examples of the amorphous carbon include carbon or carbon compositions generally referred to as amorphous carbon, fine grain, amorphous carbon, glassy carbon, and the like. The main component of these amorphous carbons is carbon, but in addition, they usually contain heteroatoms such as hydrogen, oxygen, and nitrogen, and in many cases metal atoms such as iron, and organic components such as ash. It is known to contain.

) t1 amorphous carbon includes carbon blur 2,
List of examples include coke, plants of 5 types, minerals of 5 types, animals of 5 types, synthetic resins of 5 types, and various activated carbons obtained by activating these 5 types or other various carbon materials or carbonaceous materials. Can be done.

Among these various amorphous carbons, porous amorphous carbon, which is usually used as a catalyst carrier or adsorbent, is preferred, and for example, the specific surface area is 200 m''/g7
G or larger carbons can be suitably used, with activated carbon being particularly preferred.

There is no particular restriction on the shape of the penta-element carrier (above) or the solid catalyst substance, and they can be used in various shapes or molded products, such as powder, strips, cross, and cylinder.

The palladium carbon in the present invention may be, for example, a commercially available palladium catalyst supported on activated carbon, palladium carbon catalyst, palladium hydroxide catalyst supported on activated carbon, etc., which may be used in the reaction as is or after an activation treatment such as a reduction treatment. Alternatively, it can be newly prepared and used by various methods from the carbon and various palladium compounds and metallic palladium.

Palladium compounds that can be used in the haladium black or palladium carbon no palladium component described in '61 include palladium halides such as palladium fluoride, palladium chloride, palladium bromide, and palladium iodide;
Inorganic and organic acid salts of palladium such as palladium nitrate, palladium sulfate, palladium acetate, palladium acetylacetonate, palladium sulfide; tetraamine palladium dichloride, hexachloropalladate, hexachloropalladate sodium salt, tetrachloropalladate, dinitro Palladium inorganic complex compounds such as diamine palladium dichloride: palladium oxide.

Palladium hydroxide; [Pd(Co)CjLz]
2, palladium carbonyl complexes such as [Pd(Co)2C]2, palladium diisonitrile complexes, [Pc
IC statement 2 (olefin)]2. [pdlph3)2
(olefin)], [PdC love (η3-C3H5)]
2, palladium olefin or allyl complex such as [Pd(η3-C3Hs) 2 ], [η5-C585Pd
Palladium cyclopentagenyl complex such as [C]
Palladium phosphine complexes such as Pd (PP h3) 4 ], [(CH3) 2PdPPh31, [CH3
Examples include palladium compounds such as various organic palladium compounds such as palladium alkyl complexes such as palladium alkyl complexes, palladium aryl complexes, and palladium acyl complexes. In addition, examples of the metallic palladium include colloidal palladium, Mi particulate palladium, and the like. Among these various palladium compounds and metallic palladium, halogenated palladium such as palladium chloride, tetrachloropalladium, hexachloropalladium acid, palladium hydroxide, and colloidal palladium are preferable, and palladium dichloride and tetrachloropalladium acid are preferable.

The various palladium compounds and metallic palladium may be used alone or in combination in preparing the catalyst.
You may use combinations of more than one species.

Further, the various palladium compounds may be anhydrous or hydrated, and can be used in various forms such as an aqueous solution, suspension, acidic solution, alkaline solution, or dissolved in an organic solvent. can.

Methods for preparing the catalyst include 1 adsorption method from a solution such as an ordinary aqueous solution, impregnation method, immobilization method, dry mixing method, wet kneading method, vapor phase sublimation adsorption method, vapor phase evaporation method, crushing method, etc. Support can be prepared by various methods. For example, as a method for supporting palladium chloride, method A is preferably used, which is an impregnation method using an acidic aqueous solution of palladium chloride in hydrochloric acid.

Support 3 using the above method! The produced solid can be used as it is as a catalyst in a reaction, but is usually activated by reduction or decomposition treatment to produce highly dispersed metallic palladium and highly dispersed palladium hydroxide components on a carbon carrier. It is preferable to use it in the reaction as a so-called supported palladium catalyst.

The reduction method includes a wet reduction method using aldehydes such as sodium formate and formaldehyde, an aqueous or alkaline solution of oxalic acid and hydrazine, or -
Conventional reduction methods can be used, such as dry reduction with reducing gases such as carbon oxide, hydrogen, and ethylene.

The wet reduction treatment can be carried out usually at 0 to 100°C, preferably at room temperature to 90°C. In addition.

This wet reduction treatment may be performed at the same time as the support preparation of the palladium compound, or may be performed before drying the support preparation solid. After separating from the solution by a separation method such as a state, it can be dried by a conventional drying method such as vacuum drying, heat drying, gas flow drying, etc., and can be used as a catalyst in a reaction.

On the other hand, in the dry reduction treatment or thermal decomposition treatment, after separating the liquid such as a solution or a solvent from the supported solid by various methods or impregnation to dryness, if necessary, further conventional drying methods are used. and dry the obtained solid at, for example, 100 to 500°C, preferably 150 to 300°C.
The heat treatment can be carried out at a temperature of 0.degree. C. under the above-mentioned reducing gas or an inert gas such as nitrogen or helium, or under real gravity. Through such treatment, highly dispersed metallic palladium is produced on carbon A supported, and a so-called palladium carbon catalyst can be prepared. Depending on the reaction, it can be subjected to pretreatment such as reduction treatment or steam treatment before being used as a catalyst in the reaction.

Next, 1.10- as an important component in this invention
There are no particular restrictions on phenanthroline, but it is usually preferable to use it after purification.

In the method of this invention, the palladium-based catalyst, -
Phenol can be produced by oxidizing the benzene in the presence of carbon oxide and 1,10-phenanthroline.

As the oxidizing agent required for oxidation, oxygen gas and peroxides capable of generating oxygen can be used.

Oxygen gas can be supplied by blowing into the reaction system.

Examples of the peroxide include hydrogen peroxide, peracids such as peracetic acid, hydroperoxides such as t-butyl hydroperoxide, benzoyl peroxide, and lauroyl peroxide.

In any case, in this invention, oxygen gas is preferred as the oxidizing agent.

A solvent can be used during the oxidation.

The solvent used in the method of the present invention is not particularly limited as long as it is inert to this oxidation reaction, and examples thereof include acetic acid, propionic acid, butanoic acid, and the like.

Preferred is acetic acid. Furthermore, these solvents may contain water; however, in the method of this invention, wood is not an essential component of the reaction system and does not inhibit the oxidation reaction. There is no need to worry about this tree.

In the oxidation reaction, the amount of each component cannot be generally specified, but in general, the amount of the palladium-based catalyst is 0.05 to 30% per mole of benzene in terms of palladium metal. .0g atoms, especially 0.0g atoms.
30 to 3.00 g 'fX child is preferable, and 1. The amount of to-phenanthroline used is desirably 1 to 5.0 mol, preferably 0.5 to 2.0 mol, Q per palladium metal atom.

The amount of solvent to be used may be appropriately determined in consideration of removal of reaction heat, ease of stirring, and the like.

The reaction temperature is usually 120 to 250°C, preferably 1
If the zero reaction temperature, which is 50 to 220°C, is lower than 120°C, the conversion rate of benzene may be low and productivity may be low.

On the other hand, if the reaction temperature is higher than 250°C, the selectivity to phenol may be low or the catalyst activity may be significantly deteriorated.

The pressure of the reaction is usually 5 to 30K g/cm'
G, preferably 7 to 25 Kg1Crn'G. The reaction pressure is determined by the autogenous pressure of the reaction system, that is, the carbon oxide pressure, the vapor pressure of benzene, the vapor pressure of the product, or the vapor pressure of an inert solvent or inert gas used as the case requires. Can be done.

If the pressure of the reaction is lower than 5 Kg/crn''G, i.e., if the pressure of -carbon oxide is low, the selectivity of phenol may decrease significantly. Carbon monoxide is essential in the reaction. , pressure is 30Kg/ctn
If the pressure of carbon oxide is too high, the yield of phenol may be low. That is, in order to improve the yield of phenol, there is an appropriate range for the pressure of -carbon oxide. The reason for this is not clear, but for example, by coordinating carbon monoxide to palladium in the catalyst in an appropriate proportion, the reaction selectivity of benzene improves; on the other hand, if the pressure is too high, palladium It can be considered that the number of active sites decreases as the phenol is coated with carbon monoxide, resulting in a decrease in the yield of phenol.

The reaction time for the above reaction is usually 0.5 to 5 hours, preferably 1 to 3 hours. If this reaction time is shorter than 0.5 hours, the conversion rate of benzene may become low;
Even if the reaction time is longer than 1, it is usually not possible to expect an increase in phenol yield commensurate with the extension of the reaction time, and productivity may decrease.

The reaction may be carried out using a batch method or a semi-batch method.2. ! The reaction can be carried out by various reaction methods and reaction operations such as the I-continuation method.

Further, the catalyst may be used in a slurry state, a fixed bed, a moving bed, or a fluidized bed.

There is no particular restriction on the order of contacting each component of the reaction raw material with the catalyst.

After the reaction, the reaction product can be separated and recovered from the solid such as the catalyst automatically or by a conventional separation method such as filtration or distillation.

This recovered reaction product contains the target product, phenol.

It can be separated and purified from the recovered reaction product by ordinary separation and purification methods such as Zum distillation, solvent extraction, sequential treatments such as alkaline water treatment and acid treatment, or operations that suitably combine these. . Further, a portion of the reaction product and/or unreacted benzene after separating the phenol can be recycled to the reaction system and used again.

When the reaction is carried out batchwise, the catalyst recovered by separating the reaction product after the reaction may be used as is or
After regenerating part or all of it, it can be used repeatedly as a catalyst in reactions.

When the reaction is carried out in a continuous manner, the catalyst, which has been partially or completely deactivated by being subjected to the reaction, can be regenerated and used for the reaction after the reaction is interrupted, or
A part of the catalyst can be continuously or intermittently extracted from the reactor during the reaction, regenerated in a catalyst regenerator, and recycled to the reactor again for use in the reaction.

[Effect of Phase III] According to the present invention, phenol can be selectively and easily produced by directly oxidizing benzene.

In the method of this invention, one reaction is as follows compared to the conventional method:
Since it can be carried out under mild conditions such as low temperature and low pressure, it is extremely advantageous in terms of safety, process safety, and economy.

That is, the present invention can provide a novel method for producing phenol that is industrially superior.

[Example] (Example 1.2) 49.2g of palladium plate of Pd river was cut into pieces and placed in 400m of sewage.
This was dissolved in 1 and left overnight. Thereafter, 400 mg of sodium formate and 200 ml of water were added, and the mixture was allowed to stand overnight for further reduction.

Thereafter, the product was thoroughly washed with warm water every day, washed with n-hexane and acetone, and dried under reduced pressure in a desiccator to obtain palladium black.

A 200 m long autoclave was charged with each component shown in Table 1 in the amount shown in Table 1, and the pressure inside the autoclave was raised to the pressure shown in Table 1 with a mixed gas of carbon monoxide and oxygen. The oxidation reaction was carried out under the conditions shown in Table 1.

After the reaction was completed, the pressure was removed and the resulting solution was analyzed by gas chromatography.

The analysis results are shown in Table 1.

(Example 3) The same procedure as in Example 1 was carried out except that no solvent was used.

The results are shown in Table 1.

(Example 4) 0.82 g of palladium chloride of Pd--"' was dissolved in a mixture of 2.0 mM of 2N hydrochloric acid and 5.0 mM of wood, and 14 mJ1 of water was added, and after heating to 80 °C, In addition, powdered amorphous carbon 9
．． 2g of sodium formate and 3g of sodium carbonate were added and stirred at 80°C for 5 minutes.
After reducing at 100° C. for 10 minutes, it was filtered and dry-cooked at 100° C. for 1 hour to obtain 5% palladium on carbon.

Quality: 1 Direct oxidation was carried out in the same manner as in Example 1, except that the %wt% palladium carbon obtained in the above preparation example was used. The results and reaction conditions are shown in Table 1.

(Comparative Example 1) The same procedure as in Example 1 was carried out except that 1.10-phenanthroline was not used.

The results are shown in Table 1.

(Comparative Example 2) The same procedure as in Example 1 was carried out except that carbon monoxide was not used and the reaction time was 6 hours.

The results are shown in Table 1.

As shown in Table 1, even in the presence of a palladium catalyst, 1. In the absence of lO-phenanthroline,
Phenol yield and selectivity are low, and the absence of -carbon oxide results in extremely low phenol yield and selectivity.

Claims (2)

[Claims] (1) A method for producing phenol, which comprises oxidizing benzene in the presence of 1,10-phenanthroline and carbon monoxide using a palladium-based catalyst. (2) The method for producing phenol according to claim 1, wherein the catalyst is palladium black and palladium carbon.