JP3979127B2 - Method for producing phenyl ester - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a phenyl ester by reacting benzene, an organic carboxylic acid and molecular oxygen in the presence of a specific catalyst. The product phenyl ester, such as phenyl acetate, can be easily hydrolyzed to produce phenol.
[0002]
[Prior art]
Various methods for producing phenyl ester by reacting benzene, organic carboxylic acid and molecular oxygen in the gas phase or liquid phase in the presence of a specific catalyst have been proposed. In this reaction, a noble metal belonging to Group VIII of the periodic table, particularly palladium, is used as a catalyst.
[0003]
For example, Japanese Patent Publication No. 46-33024 discloses a method for producing a phenyl ester using palladium or platinum as a catalyst. In Japanese Patent Publication No. 48-18219, in order to obtain a catalyst with higher activity, a catalyst added with Group IV, V and VI elements of the periodic table, in particular bismuth and tellurium, is used as an activity promoter for palladium or platinum catalysts. A method of reacting in the presence of an alkali metal acetate has been proposed. However, in this method, the activity of the catalyst is low, and a large amount of alkali metal acetate is required, which is not necessarily industrially practical.
In Japanese Patent Publication No. 55-15455, cadmium, zinc, uranium, tin, lead, antimony, bismuth, tellurium and thallium are added as promoters to produce phenyl acetate in the presence of a mixture of an alkali metal fatty acid salt and nitric acid. Although the method is disclosed, the activity of the catalyst is not sufficient, and in addition to the fact that a large amount of alkali metal acetate is required, the use of nitric acid has problems such as corrosion of the equipment. From a practical point of view.
[0004]
In the case of the reaction in the liquid phase, palladium as a catalyst component elutes into the reaction solution, and there is a disadvantage that the catalytic activity decreases with time and expensive palladium is lost. For this reason, Japanese Patent Application Laid-Open No. 63-174950 proposes a method in which bismuth or lead is present in the reaction system as a method for suppressing elution of palladium. However, in this method, by supplying bismuth and lead, elution of palladium as a catalyst component can be improved when the raw material oxygen concentration is low, but when the raw material oxygen concentration is increased to an industrial practical level, the elution of palladium is improved. Occasionally, long-term continuous operation is difficult and uneconomical because expensive palladium is lost.
[0005]
Moreover, when performing reaction in a gaseous phase, it has the fault that activity fall is recognized in a short time.
[0006]
As described above, the conventional methods are not satisfactory in terms of industrial practicality.
[0007]
[Problems to be solved by the invention]
Thus, the present invention provides a method for economically producing a phenyl ester by reducing loss of expensive palladium as a catalyst component when reacting benzene, an organic carboxylic acid and molecular oxygen in the presence of a catalyst. That is.
[0008]
[Means for Solving the Problems]
The present inventors diligently studied in order to solve the problems of the prior art as described above. As a result, in producing phenyl ester by reacting benzene, organic carboxylic acid and molecular oxygen in the presence of a solid catalyst on which palladium is supported, the reaction is carried out in the presence of carbon monoxide, so The inventors have found that phenyl ester can be produced economically with reduced elution, and the present invention has been completed.
[0009]
That is, the present invention is characterized in that when benzene, an organic carboxylic acid and molecular oxygen are reacted in the presence of a palladium-supported solid catalyst to produce a phenyl ester, the reaction is performed in the presence of carbon monoxide. It relates to a method for producing a phenyl ester.
[0010]
Hereinafter, the present invention will be described in detail.
[0011]
The amount of carbon monoxide supplied is preferably 0.005 to 30% by volume, particularly preferably 0.05 to 30% by volume, based on the amount of molecular oxygen supplied.
[0012]
As molecular oxygen, oxygen may be used as it is, but in order to remove the reaction gas composition from the explosion range, a gas obtained by diluting oxygen with an inert gas such as nitrogen, helium or carbon dioxide, or air can be used. .
[0013]
The supply amount of molecular oxygen is appropriately set depending on the reaction type and amount of catalyst, preferably 0.001~100kg / cm ² as an oxygen partial pressure of the solid catalyst layer among them, among others 0.01~50kg / cm ² is Particularly preferred.
[0014]
The method for supplying carbon monoxide is not particularly limited, and examples thereof include a method for supplying carbon monoxide continuously or intermittently. Further, the carbon monoxide supply amount can be appropriately changed according to the change in the palladium elution concentration.
[0015]
The palladium-supported solid catalyst used in the present invention is preferably a solid catalyst having an activity of producing a phenyl ester from benzene, an organic carboxylic acid and molecular oxygen, and having palladium supported on a carrier. A catalyst in which tellurium is supported with palladium as a cocatalyst is preferable because of its high activity.
[0016]
Examples of the carrier for supporting palladium include silica, silica alumina, alumina, zirconia, activated carbon, diatomaceous earth, zeolite, and the like, and silica and zirconia are particularly preferable.
[0017]
In the solid catalyst on which palladium is supported, the amount of palladium supported on the support is preferably 0.01 to 10% by weight as palladium metal with respect to the total weight of the catalyst including the support and the cocatalyst, and in particular, 0.1% ˜5% by weight is particularly preferred.
[0018]
The amount of tellurium in the case where the solid catalyst carrying palladium is a catalyst carrying palladium and tellurium which is a promoter is tellurium / palladium metal atomic ratio (hereinafter referred to as Te / Pd ratio) = 0.01. 10 is preferable.
[0019]
The starting material of palladium or tellurium used for the preparation when preparing a solid catalyst carrying palladium, particularly palladium, or a catalyst carrying palladium and tellurium, can be selected as appropriate. Can be used raw materials used to prepare ordinary palladium catalysts, such as palladium metal, ammonium hexachloropalladate, sodium hexachloropalladate, ammonium tetrachloropalladate, potassium tetrachloropalladate, sodium tetrachloropalladate, Potassium tetrabromopalladate, palladium oxide, palladium chloride, palladium bromide, palladium iodide, palladium nitrate, palladium acetate, potassium dinitrosulfite palladium acid, chlorocarbonyl Indium, dinitrodiammine palladium, tetraammine palladium, dichloro-diammine palladium, dichloro (ethylenediamine) palladium, potassium tetracyano palladium acids and the like can be used.
[0020]
Examples of tellurium raw materials in the case of using tellurium include metal tellurium, tellurium chloride (II), tellurium chloride (IV), tellurium oxide (IV), tellurium oxide (VI), telluric acid (H ₆ TeO ₆ ), tellurium. Examples include potassium acid and sodium tellurate.
[0021]
The method for preparing the palladium-supported solid catalyst can be selected as appropriate, and can be supported on a carrier by a commonly used method. For example, impregnation method, deposition method, ion exchange method Etc. are used.
[0022]
When preparing a solid catalyst carrying palladium and tellurium by the impregnation method, the palladium raw material and the tellurium raw material may be impregnated and supported at the same time, or after impregnating and supporting one of them, the remaining raw materials are impregnated. It may be supported.
[0023]
After the loading, the solvent is removed by an operation such as decantation, filtration, heating or heating under reduced pressure according to a conventional method such as an impregnation method or an ion exchange method. Drying after removing the solvent can be performed by heating, drying under reduced pressure, or the like.
[0024]
Either a method of reducing directly after drying, or a method of reducing after decomposing the palladium raw material or the palladium raw material and the tellurium raw material by firing in air may be used.
[0025]
Firing is preferably performed at 100 to 1000 ° C. in an atmosphere of oxygen, oxygen diluted with an inert gas such as nitrogen, helium, or argon, or air.
[0026]
A known method is used to reduce the solid catalyst. For example, a method of reducing in the gas phase using hydrogen, carbon monoxide, ethylene, methanol or the like as a reducing agent, or a method of reducing in the liquid phase using hydrazine hydrate, formalin, formic acid or the like. Can do. The reduction temperature in the case of reduction in the gas phase is preferably 100 to 1000 ° C, and particularly preferably 200 to 800 ° C.
[0027]
In the method of the present invention, benzene, an organic carboxylic acid and molecular oxygen are reacted in the presence of carbon monoxide in the presence of a catalyst on which palladium is supported.
[0028]
As the organic carboxylic acid used in this case, any organic carboxylic acid corresponding to the target product phenyl ester can be used. For example, aliphatic carboxylic acids such as acetic acid, propionic acid and butyric acid, and aromatic carboxylic acids such as benzoic acid can be used. In the case of producing phenol by hydrolyzing the obtained phenyl ester, acetic acid and propionic acid which are inexpensive and available in large quantities are preferable, and acetic acid is particularly preferable. Benzene is not particularly limited. In the reaction, a solvent may be added as necessary.
[0029]
The ratio of benzene and organic carboxylic acid can be selected as appropriate, and among them, the production efficiency is excellent, and therefore the molar ratio of benzene / organic carboxylic acid is preferably 1 / 0.1 to 1/100.
[0030]
The reactor is not particularly limited, and conventionally known, for example, a fixed bed flow reactor, a multitubular reactor, a batch reactor, a suspension bed reactor and the like are used.
[0031]
The relationship between the supply amount of benzene and organic carboxylic acid and the amount of catalyst may be appropriately selected depending on the reaction method. For example, in the case of a fixed bed, the total supply amount of benzene and organic carboxylic acid per unit solid catalyst volume and unit time. (Hereinafter referred to as LHSV) is preferably 0.1 to 50 h ⁻¹ , particularly preferably 0.1 to 30 h ⁻¹ . In the case of a suspended bed, the solid catalyst concentration is preferably in the range of 0.05 to 30% by weight with respect to the raw material.
[0032]
The reaction temperature is preferably from 100 to 300 ° C, particularly preferably from 100 to 250 ° C, in order to allow the reaction to proceed efficiently.
[0033]
The reaction pressure may be a pressure equal to or higher than normal pressure, but benzene and a part of the organic carboxylic acid must be in a liquid phase, and preferably 1 to 200 kg / cm ² .
[0034]
【Example】
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
[0035]
In addition, the measurement conditions by the gas chromatography of a reaction liquid used capillary column (type: BP21, column length: 25m) by SGE, raised column temperature from 60 degreeC to 230 degreeC, and set FID as a detector. And measured.
[0036]
The concentration of palladium eluted in the reaction solution was measured using an atomic absorption spectrometer (AAnalyst 800 manufactured by PerkinElmer). Atomization was carried out using a furnace method, and the absorbance at a wavelength of 247.6 nm was detected by a high-wavelength band semiconductor detector and measured.
[0037]
Example 1
0.291 g of telluric acid was dissolved in 10.86 g of an aqueous solution of 8.3% by weight of dinitrodiammine palladium nitrate in terms of palladium. This aqueous solution was impregnated in 30 g of zirconia (manufactured by Norton) and then dried under reduced pressure at 50 ° C. and 0.02 kg / cm ² . After drying, the catalyst was reduced at 600 ° C. in a hydrogen stream to obtain a catalyst.
[0038]
10 ml of this catalyst was filled in a stainless steel reaction tube having an inner diameter of 13 mm, the reaction temperature was 190 ° C., the reaction pressure was 40 kg / cm ² , 2.2 g / min of equimolar mixture of benzene and acetic acid, and 37 ml / min of oxygen ( (0 ° C., converted to 1 atm) and nitrogen was supplied at 173 ml / min (0 ° C., converted to 1 atm) to react.
[0039]
When the reaction product was collected at 71 hours after the start of the reaction and analyzed by an atomic absorption spectrometer, the palladium concentration in the effluent reaction solution was 87 ppb in terms of metallic palladium. The reaction was continued, and at 72 hours after the start of the reaction, 0.1 ml / min of carbon monoxide was supplied without changing the supply amounts of benzene, acetic acid, oxygen and nitrogen. The concentration of carbon monoxide with respect to the molecular oxygen supply amount at this time is 0.27% by volume. When the reaction solution was collected and analyzed 73 hours after the start of the reaction, the palladium concentration in the reaction solution was 54 ppb, and the palladium elution concentration decreased with the supply of carbon monoxide.
[0040]
Example 2
The reaction was continued after Example 1. The reaction was performed under the same conditions as in Example 1 except that the supply amount of carbon monoxide was 1 ml / min from 77 hours after the start of the reaction. The concentration of carbon monoxide with respect to the molecular oxygen supply at this time is 2.7% by volume. When the reaction solution was collected and analyzed 78 hours after the start of the reaction, the palladium concentration in the reaction solution was 16 ppb, and the supply of carbon monoxide further reduced the palladium elution concentration.
[0041]
Example 3
The reaction was continued after Example 2. The reaction was performed under the same conditions as in Example 1 except that the supply amount of carbon monoxide was changed to 0.5 ml / min from 100 hours after the start of the reaction. The concentration of carbon monoxide with respect to the molecular oxygen supply at this time is 1.4% by volume. When the reaction solution was collected and analyzed 101 hours after the start of the reaction, the palladium concentration in the reaction solution increased to 28 ppb due to the decrease in the supply amount of carbon monoxide, but it was less than the initial amount. It was.
[0042]
Example 4
The reaction was continued after Example 3. The reaction was carried out under the same conditions as in Example 1 except that the supply amount of carbon monoxide was changed to 2 ml / min from 168 hours after the start of the reaction. The concentration of carbon monoxide with respect to the molecular oxygen supply at this time is 5.4% by volume. When the reaction solution was collected and analyzed 171 hours after the start of the reaction, the palladium concentration in the reaction solution was 11 ppb, and the supply of carbon monoxide further reduced the palladium elution concentration.
[0043]
Comparative Example 1
The reaction was continued after Example 4. The reaction was conducted under the same conditions as in Example 1 except that carbon monoxide was not supplied from 265 hours after the start of the reaction. When the reaction solution was collected and analyzed 270 hours after the start of the reaction, the palladium concentration in the reaction solution was 114 ppb, and the palladium elution concentration increased due to the stop of the supply of carbon monoxide.
[0044]
Example 5
0.648 g of telluric acid was dissolved in 14.48 g of an aqueous solution of 8.3% by weight of dinitrodiammine palladium nitrate in terms of palladium. This aqueous solution was impregnated in 40 g of zirconia (manufactured by Norton) and then dried under reduced pressure at 50 ° C. and 0.02 kg / cm ² . After drying, the catalyst was reduced at 600 ° C. in a hydrogen stream to obtain a catalyst.
[0045]
10 ml of this catalyst was filled in a stainless steel reaction tube having an inner diameter of 13 mm, the reaction temperature was 190 ° C., the reaction pressure was 40 kg / cm ² , 2.2 g / min of equimolar mixture of benzene and acetic acid, and 37 ml / min of oxygen ( (0 ° C., converted to 1 atm) and nitrogen was supplied at 173 ml / min (0 ° C., converted to 1 atm) to react.
[0046]
When the reaction product was collected 47 hours after the start of the reaction and analyzed with an atomic absorption spectrometer, the palladium concentration in the effluent reaction solution was 130 ppb in terms of metallic palladium. The reaction was continued, and at 50 hours after the start of the reaction, 0.2 ml / min of carbon monoxide was supplied without changing the supply amounts of benzene, acetic acid, oxygen and nitrogen. The concentration of carbon monoxide with respect to the molecular oxygen supply at this time is 0.54% by volume. When the reaction solution was collected and analyzed at 53 hours, 190 hours, and 382 hours after the start of the reaction, the palladium concentrations in the reaction solution were 58, 64, and 60 ppb, respectively. The palladium elution concentration decreased, and the palladium elution concentration could be stably reduced even after the reaction time had elapsed.
[0047]
Example 6
0.648 g of telluric acid was dissolved in 14.48 g of an aqueous solution of 8.3% by weight of dinitrodiammine palladium nitrate in terms of palladium. This aqueous solution was impregnated in 40 g of zirconia (manufactured by Norton) and then dried under reduced pressure at 50 ° C. and 0.02 kg / cm ² . After drying, it was calcined at 500 ° C. in an air stream and then reduced at 600 ° C. in a hydrogen stream to obtain a catalyst.
[0048]
10 ml of this catalyst was filled in a stainless steel reaction tube having an inner diameter of 13 mm, the reaction temperature was 190 ° C., the reaction pressure was 40 kg / cm ² , 2.2 g / min of equimolar mixture of benzene and acetic acid, and 37 ml / min of oxygen ( (0 ° C., converted to 1 atm) and nitrogen was supplied at 173 ml / min (0 ° C., converted to 1 atm) to react.
[0049]
When the reaction product was collected 47 hours after the start of the reaction and analyzed with an atomic absorption spectrometer, the palladium concentration in the effluent reaction solution was 135 ppb in terms of metallic palladium. The reaction was continued, and at 50 hours after the start of the reaction, 0.2 ml / min of carbon monoxide was supplied without changing the supply amounts of benzene, acetic acid, oxygen and nitrogen. The concentration of carbon monoxide with respect to the molecular oxygen supply at this time is 0.54% by volume. When the reaction solution was collected and analyzed at 53 hours, 190 hours, and 382 hours after the start of the reaction, the palladium concentrations in the reaction solution were 65, 59, and 45 ppb, respectively. The palladium elution concentration decreased, and the palladium elution concentration could be stably reduced even after the reaction time had elapsed.
[0050]
【The invention's effect】
According to the present invention, when benzene, an organic carboxylic acid and molecular oxygen are reacted in the presence of a palladium-supported solid catalyst to produce a phenyl ester, by reacting in the presence of carbon monoxide, Palladium elution due to the reaction can be reduced, and the phenyl ester can be produced economically.

Claims (3)

Production of phenyl ester characterized by reacting benzene, organic carboxylic acid and molecular oxygen in the presence of palladium-supported solid catalyst to produce phenyl ester. Method. The method for producing a phenyl ester according to claim 1, wherein the supply amount of carbon monoxide is 0.005 to 30% by volume with respect to the supply amount of molecular oxygen. The method for producing a phenyl ester according to claim 1, wherein the solid catalyst is a solid catalyst on which palladium and tellurium are supported.