JPS5849328A - Preparation of ethenylphenol - Google Patents

Abstract

PURPOSE:To prepare the titled compound in high conversion and selectivity, keeping the activity of the reaction catalyst for a long period, by dehydrogenat ing an ethylphenol compound in the presence of a high performance oxide catalyst containing barium and tin and stable structurally even at a high temperature. CONSTITUTION:The objective compound is prepared by dehydrogenating an ethylphenol compound at 500-600 deg.C at a liquid hourly space velocity (LHSV)of 0.1-10hr under atmospheric pressure or a slight negative pressure in the presence of a catalyst comprising an oxide containing Ba and Sn or a combination of said oxide with one or more metal oxides selected from vanadium oxide, manganese oxide, iron oxide, copper oxide, zinc oxide, zirconium oxide, molybdenum oxide, antimony oxide, bismuth oxide and cerium oxide. The ratio of the oxide containing Ba and Sn to the metal oxides is preferably 0.1-10 in terms of atomic ratio of (Ba+Sn)/metal. The performance of the catalyst can be stabiliz ed by heat-treating the catalyst at 400-1,000 deg.C for 1-50hr prior to the reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for dehydrogenating ethylphenols to produce the corresponding ethynylphenols.

Conventionally, methods for dehydrogenating alkanes and aromatic hydrocarbons having alkyl side chains to obtain corresponding unsaturated compounds, methods for dehydrogenating alkenes to produce dienes, etc. have been widely studied1. Many catalysts effective for these reactions have been discovered and are widely used industrially. Furthermore, among these catalysts, chromium oxide, iron oxide, r-alumina,
It is also well known that a catalyst made of oxidized steel in combination with magnesium oxide, potassium oxide, etc. has excellent performance.

However, since ethylphenols have an active phenolic hydroxyl group in their molecules, their reactivity is significantly different from that of alkylbenzenes such as ethylbenzene.
Journal of Agelide Chemistry, Vol. 7, pp. 172-182, April 1975; Chemikano ν Abstracts, Vol. 70, 28534w: Hatsune Shoten Publishing.
Daikichi Ki Kagaku J Vol. 14, p. 83; Chemical Abstracts, Vol. 64, 15039g), Even if the above dehydrogenation catalyst for hydrocarbons is applied to the dehydrogenation of ethylphenols, there will be no isomerization, disproportionation, or dealkylation. Undesirable reactions such as oxidation, decomposition, dehydration condensation, coking on the catalyst surface, and polymerization of dehydrogenated products proceed significantly, and the selectivity of the reaction to the target ethynylphenols is low, making it impractical.

In addition, tin oxide alone or tin oxide combined with metal tin, magnesium oxide, chromium oxide, zinc oxide, etc. is already known to be effective as a dehydrogenation catalyst for ethylphenols. The performance of these catalysts is still not fully satisfactory.

The present inventors conducted intensive research to obtain a catalyst for the dehydrogenation reaction of ethylphenols, and found that oxides containing barium and soot, or such oxides include vanadium oxide, manganese oxide, iron oxide, and steel oxide. A catalyst that combines one or more metal oxides selected from the group consisting of , zinc oxide, zirconium oxide, molybdenum oxide, antimony oxide, bismuth oxide, and cerium oxide has extremely excellent performance in the dehydrogenation reaction of ethylphenols. The present invention was completed based on the discovery that it has high activity, high selectivity, and long catalyst life that is stable for a long period of time, and is structurally stable even at high temperatures.

That is, the gist of the present invention is to provide a method for dehydrogenating ethylphenols to produce corresponding ethynylphenols, in which an oxide containing barium and soot, or vanadium oxide, manganese oxide, acid, iron oxide, A method for producing ethynylphenols containing one or more metal oxides selected from the group consisting of steel oxide, zinc oxide, zirconium oxide, molybdenum oxide, antimony oxide, soot oxide, and cerium oxide.

In the present invention, the oxide containing barium and soot may be a simple mixture of barium oxide and tin oxide, or a part or all of it may be in the form of a complex oxide such as barium stannate. It can be anything.

These oxides can be prepared by mixing barium oxide and tin oxide and heating and calcining the mixture, using organic salts such as barium oxalate and tin oxalate or barium acetate and tin acetate, or other methods of preparing barium and soot. A method of mixing and heating various inorganic salts such as organometallic compounds, hydroxides, halides, carbonates, nitrates, etc., or a method of mixing aqueous solutions of various inorganic or organic salts of barium and soot to produce ammonia, amines, etc. A method in which the gel produced by adding a basic compound to make it weakly alkaline is filtered, washed, dried, and fired.The oxide of either barium or soot is impregnated with an aqueous solution of the metal salt of the other, then dried and fired. or other generally known methods. The barium and soot-containing oxides obtained by these methods can be used as catalysts as they are by adjusting the particle size to an appropriate size, or they can be used by extrusion molding.
In addition, the atomic ratio of barium to soot in the oxide containing barium and soot is preferably in the range of about 0.03:1 to 1021, particularly about 0.0γ to i; Parts may be in forms other than conventional oxides such as barium peroxide or barium carbonate.

Next, when combining the oxide containing barium and soot with other metal oxides mentioned above, use the general mixing method, dipping method,
Preparation by coprecipitation method or any other known method] 7. For example, a method in which these metal oxides are directly mixed with an oxide containing barium and soot and molded, a chloride of these metals, A method in which the oxide is immersed in an aqueous solution of various inorganic or organic salts such as carbonates, sulfates, and nitrates, and a base such as ammonia is added to the solution, followed by drying and firing along with the resulting precipitate. Examples include a method of mixing an aqueous solution of an inorganic or organic salt with an aqueous solution of a metal salt to be combined, adding aqueous ammonia, and drying and calcining the resulting precipitate. The catalyst obtained in this way can be used in the reaction by pulverizing it to an appropriate particle size, as in the case of the oxide containing barium and soot alone, or it can be used by extrusion or tableting. You can also do it.

The blending ratio of oxides containing barium and soot and these metal oxides is not particularly limited, but may be 1 (Ba+Sn).
/metal atomic ratio of about 0.01 to 100, particularly about 0.1 to 10 is preferred.

In addition, although the catalyst used in the method of the present invention does not normally need to be forced into a carrier, it may be used in combination with a carrier if necessary, such as when a particularly large mechanical strength is required. can. It is necessary to use an inert carrier such as α-alumina, silicon carbide, or diatomaceous earth as a carrier for this i-combination, and if an active carrier such as r-alumina or silica is used, carbonaceous precipitation may occur. This is not preferable because it increases side reactions. Furthermore, the catalyst used in the method of the present invention is preliminarily prepared with a
Heat treatment may be performed at 0' to 1000°C for about 1 to 50 hours.

Next, in the present invention, ethylphenols which are reaction raw materials are ethylphenols having an ethyl group at the ortho, meta or para position relative to the phenolic hydroxyl group, and 1 to 4 of the aromatic nuclei of these ethylferrules. This refers to a compound in which five hydrogen atoms have been substituted with a methyl group or a methoxy group, or a compound in which one of the hydrogen atoms bonded to the alpha atom of the methyl group in the above compound has been substituted with a methyl group.

The reaction temperature is generally between about 400 and 750°C, preferably between about 500 and 600°C. Approximately O51~10 hr'
A range of is usually adopted. The reaction pressure can be normal pressure, reduced pressure, or increased pressure, but it is practical to carry out the reaction at a slight reduction from normal pressure. From an equilibrium perspective, the dehydrogenation reaction is easier to proceed under reduced pressure. However, from an industrial perspective, it is advantageous to slightly increase the pressure in the construction and operation of the equipment, so it is also advisable to lower the partial pressure of the reaction raw materials using a diluent or the like to achieve the desired purpose. In this case, carbon dioxide, nitrogen, water vapor, phenol, etc. can be used as the diluent, but generally water vapor or water vapor and nitrogen are used, which have the effect of suppressing carbonaceous precipitation and supplying part of the reaction heat. Preference is given to using mixtures of. The molar ratio of the diluent and ethylphenol introduced into the reaction system is usually in the range of about 2 to 200, particularly about 2 to 100. Further, the reaction is carried out in a catalytic flow system, and the catalyst bed used may be of any type, such as a fixed bed, moving bed, or fluidized bed.

According to the present invention, the corresponding ethynylphenols can be produced at high conversion and selectivity by bringing these ethylphenols into contact with the catalyst at high temperatures, and the catalyst has the advantage that its activity lasts for a long time. The method of the present invention will be specifically explained below with reference to Examples and Comparative Examples.Example 1: 90% by weight of stannic oxide and 8% by weight of 109-8% by weight of stannic oxide were thoroughly mixed. Then, 5% by weight of water was added and mixed well, and then dried at 120°C for 1 day.Next, 1% by weight of graphite was added and mixed well, and a diameter of 3/16
This molded product was molded into tablets of inch, length 4', mmQ size, and was baked in air at 650°C for 8 hours, and then
This calcined product was crushed to a particle size of 6 to 10 mesh to prepare an oxide catalyst containing barium, lithium, and tin.
This catalyst 10- was filled in a quartz reaction tube, reaction temperature was 550°C, LH8V 1. Para-ethylphenol was supplied together with water in a 10-fold molar amount at Ohr', and the reaction was carried out for approximately 5 hours. As a result of analyzing the reaction product by gas chromatography, gel permeation chromatography and Karl Fischer, the conversion rate of para-ethylphenol was 3.
The composition (mol%) of the reaction product is 96.3% of varaethinylphenol, 0.1% of varaethinylphenol 2ffi, 0% of oligomer of 31 or more, phenol and/or (Phenol such as Raffresol!1J was 11.8%, and other 10-decomposed products were 1.8%.Next, using this catalyst, dehydrogenation reaction (550℃, 5 hours) and combustion regeneration (550℃, 5 hours) were performed. 6
The conversion rate of paraethylphenol was 35 to 38%, and the composition (mol%) of the reaction product was the total of paraethylphenol and its dimer or higher oligomer. A value of 96 to 98% was consistently obtained.

Comparative Example 1 After adding 3% by weight of paraffin wax to the stannic oxide powder and mixing well, the powder had a diameter of 5 mm and a length of '
The mixture was compressed into 4 mm tablets, calcined in air at 550°C for 5 hours, and crushed to prepare a catalyst with a uniform particle size of 6 to 10 meshes. A quartz reaction tube was filled with this catalyst lO-, and para-ethylphenol was dehydrogenated under the same reaction conditions as in Example 1. As a result, the conversion rate of para-ethylphenol was 35.1%, and the composition of the reaction product was (mol%)
C. 87.8% of each varaethinylphenol, total of oligomers of dimer or higher of varaethinylphenol 5.1%
%, phenols such as phenol and cresol2.
3%, and other decomposed products were 4.8%. In addition, as a result of repeating the reaction and combustion regeneration 15 times or more using this catalyst in the same manner as in Example 1, the conversion rate of paraethylphenol was 30 to 35%, and the composition (mol X) of the reaction product was A value of 93 to 95% was consistently obtained for the total amount of phenol and its dimer or higher oligomer.

Comparing this result with the result of Example 1-, it is clear that both the conversion rate of paraethylphenol and the selectivity of paraethinylphenol are far superior when using an oxide catalyst containing barium and tin. It is.

Example 2 When the same reaction as in Example 1 was carried out on a 100 times scale, that is, by filling a stainless steel reactor with the catalyst amount IL, no difference was observed due to the increase in the size of the experimental apparatus. The conversion rate of paraethylphenol was 37.3%, and the total proportion of paraethinylphenol and its oligomer in the reaction product 11- was 96.4 mol%.

Example 3 The reaction was carried out in the same manner as in Example 1 except that the reaction time was 24 hours. As a result, the conversion rate of paraethylphenol was 36.9%, and the total production rate of paraethylphenol and its oligomer was 96%. It was .5 mol%. The results show that the oxide catalyst containing barium and tin maintains its activity for a long time in continuous reactions.Example 4 The same oxide catalyst containing barium and tin as used in Example 1 The reaction temperature was 620°C, LJ (SV
1. As a result of carrying out the reaction for 2 hours in the same manner as in Example 1 at a molar ratio of water and para-ethylphenol of 10, the conversion rate of para-ethylphenol was 68,
The compositions (mol%) of the reaction products are 86.3% of paraethinylphenol and 1% of paraethinylphenol.
1.5% dimer of 3-12-phenol, 2.4% oligomer of 1 or more SI, 7.0% phenols such as phenol and valaclesol, and 2.85X of other decomposition products.
Met.

Example 5 In Example 4, an experiment was carried out in the same manner as in Example 4 using a catalyst supported with 30% by weight of ferric oxide instead of manganese dioxide. As a result, the conversion rate of para-, la-ethylphenol was as follows. 61.3%, and the composition of the reaction product (mol%
) are respectively varaethinylphenol 89. θ%, phenol dimer 1.3% in paraethene, oligo trimer or higher? -2.4%, phenols such as phenol and para-cresol 5.2%, and other decomposition products 2.1%
Met.

Example 6 - A catalyst in which 30% by weight of antimony oxide was supported on the same oxide catalyst containing barium and tin as used in Example 1 was used, - Reaction temperature was 550C1LH8VI. 0hr-
1. At a molar ratio of water and para-ethylphenol to 14-10, the reaction was carried out for 5 hours in the same manner as in Example 1. As a result, the conversion rate of para-ethylphenol was 41.0%, and the reaction product The composition (mol%) is 92.2% of varaethinylphenol, 0.6% of dimer of varaethinylphenol, and 1% of oligomer of trimer or higher.
．． 8%, phenols such as phenol and para-cresol 2.8%, and other decomposition products were 2.6X.

Example 7 In Example 4, an experiment was conducted in the same manner as in Example 4 using a catalyst supported with 10% by weight of cerium oxide and 15% by weight of bismuth oxide instead of manganese dioxide. The conversion rate is 70. The compositions (mol%) of the reaction products are 84.3% paraethenylphenol, 1.8% paraethinylphenol dimer, and 4.0X trimer or higher oligomer.

Phenols such as phenol and valaclesol7.
9% and other decomposition products are 2. Example 8 20% by weight of distilled water was added to a mixed powder of 75% by weight of ferric oxide, 10% by weight of tin oxide, 10% by weight of barium carbonate, and 5% by weight of cement. In addition, extrusion molding was performed using an extruder to a diameter of 3 mm and a length of 5 mm. This was aged for 3 days at room temperature, and then for another half day at 130 ml.
Dry at ℃. By calcining this at 650° C. for 5 hours, an oxide catalyst containing iron, soot, and barium was prepared.

Next, ``This catalyst 10- is filled into a quartz reaction tube and 11
Reaction temperature: 550°C, LH8V 1. 2.6 in Ohr'
-') Methyl-4-ethylphenol was supplied together with 10 times the molar amount of water, and the reaction was carried out for 5 hours. As a result, the conversion rate of 2,6-dimethyl-4-ethylphenol was 33.1%1. The composition of the reaction products (mol X) is 2
, 6-dimethyl-4-ethynylphenol 94.8%
, 2i form of 2,6-dimethyl-4-ethynylphenol 0. x%, trimer or higher oligomer 〇%, phenol,
Phenols such as cresol, methylethylphenol, 2.4.6-drimethylphenol and other decomposition products were 2.7% and 2.4%. Example 9 The barium and soot prepared in Example 1 were Using an oxide catalyst containing 1. Ohr', the reaction was carried out in the same manner as in Example 1 at a molar ratio of valisopropylphenol and water of 1/1°. As a result, the conversion rate of valisopropylphenol was 135.2%, and the composition of the reaction product ( mole%), parahydroxy-α-methylstyrene 9
2.8% 2i of rose hydroxy-alpha-methylstyrene
Example 10 In Example 1, gi#! The dehydrogenation reaction of meta-ethylphenol was carried out under the same reaction conditions as in Example 9 using the same catalyst.
As a result, the conversion rate of metaethylphenol 17- was 37.8%, and in the composition (mol%) of the reaction product, metaethynylphenol was 95.2%.
, the dimer and 3i form of metaethynylphenol were each OX.

Examples '11-15 Examples! Metal salts of copper, zinc, zirconium, molybdenum, and bismuth were added one by one to the same oxide catalyst containing barium and tin as used in the above, and the containing side of these metal elements was added to the soot element. The metal salt was supported by a conventional dipping method to a concentration of 10%, and then calcined in air at 500° C. for 4 hours to decompose and remove the nitric acid group or ammonium group of the metal salt. Example 4 using the catalyst of Kokura et al.
The dehydrogenation reaction of para-ethylphenol was carried out in the same manner as in Table 1.

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Claims (2)

[Claims] (1) A method for producing ethynylphenols by dehydrogenating ethylphenols, the method comprising using a catalyst comprising an oxide containing barium and soot. (2) An oxide containing barium and soot, selected from the group consisting of vanadium oxide, manganese oxide, iron oxide, steel oxide, zinc oxide, zirconium oxide, molybdenum oxide, antimony oxide, bismuth oxide, and cerium oxide.
Method 0 according to claim 1, characterized in that a catalyst comprising a combination of more than one metal oxide is used.