JP4472271B2 - Method for producing phenol - Google Patents

Description

＊Ｃ'ｎｏｌ：ジメチルフェニルカルビノール
＊Ｆ．Ｏ．：ジクミルペルオキシド、クミルフェノール、
メチルスチレンダイマー、Ｈ．Ｂ．（高沸点化合物）の合算
＊ＨＡ：ヒドロキシアセトン
＊ｋｇ／ｔ−Ｐｈ：フェノール１ｔあたりの生成量（ｋｇ）
【００４８】
【発明の効果】
無機酸類触媒の存在下にクメンヒドロペルオキシドを主成分とするクメン酸化生成物の分解反応及びα−メチルスチレンの生成反応を行うにあたり、クメン酸化生成物中に含まれるジメチルフェニルカルビノールの濃度が５重量％以下となるように調整することにより、フェノールやα−ＭＳの収率悪化の原因となる高沸点化合物の生成や製品フェノールの品質を悪化させるヒドロキシアセトンの生成を抑制することができ、産業上優位である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing phenol, and more particularly to a method for producing phenol, acetone and α-methylstyrene from a cumene oxidation product containing cumene hydroperoxide as a main component in the presence of inorganic acids. These are useful as intermediates for the production of synthetic resins, agricultural chemicals, dyes, pharmaceuticals and the like.
[0002]
[Prior art]
Conventionally, various methods have been proposed as methods for synthesizing phenol. Among these methods, a cumene method phenol production process in which phenol is synthesized using cumene as a starting material is generally put into practical use. In this method, cumene is oxidized with oxygen or air to produce cumene hydroperoxide (hereinafter abbreviated as CHP), and then the obtained CHP is decomposed in the presence of a mineral acid catalyst to obtain phenol and acetone. It is.
[0003]
In recent years, in a phenol plant that produces phenol, the cumene process, which has mild reaction conditions and is excellent in economic efficiency, has become the mainstream of the world's phenol production process. The production process can be roughly divided into an oxidation system and a concentration system. In the process of cleaving CHP with acid (cribbing system), mineral acid is generally used as a catalyst, and sulfuric acid is generally used.
In this cumene process, phenol and acetone are obtained as main products. At the same time, dimethylphenylcarbinol is by-produced during cumene oxidation, and α-methylstyrene (hereinafter referred to as “dimethylphenylcarbinol”) is dehydrated. , Abbreviated as α-MS). This by-product α-MS can be easily converted to cumene by a hydrogenation reaction and reused as a raw material, and can also be effectively utilized industrially as a resin modifier. .
[0004]
Moreover, in this cumene method process, α-MS and phenol react to produce cumylphenol, or methylstyrene dimer is produced by a dimerization reaction of α-MS. These substances are thermally decomposed in the recovery process of the phenol process, and some of them are recycled again. However, heavier high-boiling compounds cannot be recovered and are discharged out of the system to become fuel. Deteriorate units. As a result, a reaction that causes a decrease in the yield of the target products such as phenol and α-MS due to the decomposition reaction of CHP occurs.
In addition, in the CHP decomposition reaction, a trace amount of hydroxyacetone (hereinafter abbreviated as HA) is generated. Since this HA is difficult to be separated from phenol by distillation, the cumene process is known to require extractive distillation using a solvent, which is known to cause deterioration in steam intensity. Furthermore, it mixes with the product phenol which is the final product, and causes the product quality to deteriorate. For example, when bisphenol A is produced using product phenol mixed with HA as a raw material, the product is colored and the commercial value is significantly reduced. In addition, since HA is water-soluble, there is a problem that the COD load of wastewater is increased.
[0005]
Among these problems, as a method for suppressing side reactions that cause a decrease in the yields of phenol and α-MS, a method in which CHP is diluted with a solvent such as acetone and then an acid decomposition reaction is carried out (Japanese Patent Publication No. Sho-27). 3875, 28-4619, etc.), a method of improving the reaction system, such as a method of dividing the reaction into multiple stages (US Pat. No. 2,757,209, Japanese Examined Patent Publication No. 37-13464, etc.) Proposed. Among these prior arts, a method for performing an acid decomposition reaction of CHP diluted with a solvent such as acetone is described as a side reaction is suppressed by a dilution effect by the solvent and an improvement in contact efficiency between the acid catalyst and CHP. ing.
[0006]
In addition, the method described in US Pat. No. 2,757,209, which is a method in which the reaction is performed in multiple stages, includes, for example, a one-stage production reaction of phenol, acetone, and α-MS as the first reaction. The acid decomposition reaction is carried out under mild conditions where the acid catalyst concentration and the reaction temperature are low, compared with the method terminated in step 3, leaving a few percent of CHP in the reaction product. Next, as a second-stage reaction, a method of introducing the first-stage reaction product into a plug flow reactor and performing a reaction for decomposing the organic peroxide and dimethylphenylcarbinol present in the reaction product. It is.
[0007]
As a measure for preventing the mixing of HA in the product phenol, British Patent No. 1,231,991 describes the reaction product of the acid decomposition reaction of cumene oxidation product mainly composed of CHP, acetone, hydrocarbon Crude phenol obtained by distilling and separating low-boiling components such as alcohol and high-boiling compounds such as unreacted dimethylphenylcarbinol, cumylphenol, and methylstyrene dimer is treated with an acidic ion exchange resin and contained in the crude phenol. A method is described in which HA is converted into a high-boiling compound that is easy to be separated by distillation, and then distilled and separated.
In US Pat. No. 5,064,507, crude phenol is treated with an organic polyamine, and HA in the crude phenol reacts with the added organic polyamine to form a high-boiling compound. A method for separating compounds by distillation is described.
[0008]
However, if these methods are carried out simultaneously, there are problems such as complicating the phenol production process and requiring a large amount of equipment for removing HA. Therefore, in the cumene process, it is practically important to suppress the production of high-boiling compounds that cause a decrease in the yield of the target product and to suppress the production of HA that causes a deterioration in the quality of product phenol. It is a problem.
[0009]
In JP-B-2-51408, as a first step, the concentration of CHP in the reaction mixture is set to 0 using a backmixing reactor at a sulfuric acid concentration of 30 to 100 ppm by weight and a reaction temperature of 50 to 90 ° C. The reaction is reduced to 5-5% by weight. In the first stage reaction, the conversion rate from dimethylphenyl carbinol to dicumyl peroxide is 40 mol% or more. Next, a method is proposed in which a second stage is performed in which the dicumyl peroxide produced in the first stage reactor is decomposed at a temperature of 120 to 150 ° C. by sending it to a plug flow reactor.
[0010]
Furthermore, US Pat. No. 5,254,751 describes the first stage reaction in a non-isothermal reactor with an acid catalyst concentration of 150-500 ppm by weight, a temperature range of 50-62 ° C. and acetone. Is carried out to reduce the CHP concentration to 0.3 to 1.5%. Next, after adding ammonia water to the reaction product of the first stage, it is sent to a plug flow type reactor to decompose the dicumyl peroxide generated in the first stage reaction at a temperature of 80 to 110 ° C. A method of performing is proposed.
[0011]
In JP-A-9-20699, as the first stage, the reaction is carried out at a sulfuric acid concentration of 150 to 350 ppm by weight using a backmixing reactor at a temperature of 55 to 75 ° C. In the second step of decomposing dicumyl peroxide produced at a temperature of 120 ° C. or less, the reaction is carried out in the presence of excess acetone, thereby increasing the boiling point of α-MS and the like as a by-product of HA. A method for simultaneously suppressing life has been proposed.
[0012]
[Problems to be solved by the invention]
The present invention has been made in order to solve the problems in the conventional methods as described above in the method of obtaining phenol, acetone and α-MS from cumene oxidation products containing CHP as a main component. An object of the present invention is to provide a method for obtaining phenol, acetone and α-MS with high efficiency by suppressing by-products of boiling point compounds and HA.
[0013]
[Means for Solving the Invention]
In order to solve the above-mentioned problems, the present inventors have intensively studied a cumene method process by a one-step or multi-step method. The present inventors cleaved CHP obtained by oxidizing cumene with an inorganic acid catalyst to obtain phenol, acetone and α-MS, and the concentration of dimethylphenylcarbinol contained in the cumene oxidation product supplied. By using the cumene oxidation product with an amount of 5% by weight or less, the production of high boiling point compounds causing deterioration of the yield of phenol and α-MS and the production of HA which deteriorates the quality of the product phenol It has been found that the present invention is suppressed, and the present invention has been completed.
[0014]
In the method for producing phenol, acetone and α-methylstyrene, the cumene oxidation product adjusted so that the concentration of dimethylphenylcarbinol contained in the supplied cumene oxidation product is 5% by weight or less is used as a reactor. In the present invention, it is more preferable to carry out the reaction at a reaction temperature of 55 to 90 ° C., an acetone concentration in the reaction mixture of 20 to 70% by weight, and a CHP conversion of 95 to 99.9%.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
The term “inorganic acids” as used in the present invention is a generic term for all acids not containing carbon, and among the acids containing carbon, carbonic acid also belongs. Inorganic acids include binary acids (hydrogen acid) such as hydrochloric acid and hydrofluoric acid and oxo acids (oxygen acids) represented by sulfuric acid, nitric acid, phosphoric acid, perchloric acid and the like. In addition to such homogeneous acids, zeolites, metal oxides, generally referred to acidic ion exchange resins whose ion exchange groups are acids that do not contain carbon, and acids that do not contain carbon are also immobilized on a carrier. Solid acids such as those are also included.
Sulfuric acid is usually used for the decomposition reaction of CHP, but generally referred to as acidic ion exchange resins, zeolites, heterogeneous acid catalysts such as the aforementioned solid acids, and homogeneous acid catalysts such as heteropolyacids and borohydrofluoric acid. Etc. can be used.
[0016]
The method of the present invention is a method for producing phenol, acetone and α-MS from a cumene oxidation product mainly comprising CHP by a reaction method in which an acid decomposition reaction of CHP is mainly performed in the presence of the inorganic acid catalyst. It is.
The raw material contains the cumene oxidation product adjusted so that the concentration of dimethylphenylcarbinol contained in the cumene oxidation product is 5% by weight or less, preferably 4% by weight or less, more preferably 3% by weight or less. Supplied. Although the production method of the cumene oxidation product is not specified, the cumene oxidation product can be obtained by combining the following methods singly or in combination.
[0017]
As a method of suppressing the production of dimethylphenyl carbinol itself, for example, in the presence or absence of sodium, cumene is oxidized with air or oxygen under mild conditions, for example, at a low temperature of 110 ° C. or less, and then the product is oxidized. A method of separating unreacted cumene so as to obtain a predetermined concentration by distillation operation to obtain the cumene oxidation product can be used.
In addition, for example, under the cumene oxidation reaction conditions that are normally performed, a method of performing an oxidation reaction with a CHP concentration of the cumene oxidation product of 30% by weight or less and obtaining the cumene oxidation product by the distillation operation as described above can be used. .
[0018]
When cumene is oxidized by air or oxygen at a high temperature of 110 ° C. or higher, or when cumene is oxidized when the CHP concentration of the cumene oxidation product is 30% by weight or more, the occurrence frequency of radical termination reaction increases and the selection of CHP This is not preferable because the rate deteriorates and the amount of dimethylphenylcarbinol produced increases.
Further, for example, cumene can be produced under the reaction conditions as described above in the presence of a catalyst, specifically a radical scavenging catalyst such as TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl). A method of suppressing the production of dimethylphenyl carbinol by improving the selectivity of CHP by oxidation or the like can be used.
[0019]
Examples of the method for converting or removing dimethylphenylcarbinol produced in the cumene oxidation reaction include a chemical treatment method and a physical separation method.
As a chemical treatment method, for example, a method of oxidizing dimethylphenylcarbinol with a specific oxidizing agent in the presence or absence of a specific catalyst and a solvent to form CHP can be used.
[0020]
As the catalyst here, a solid acid catalyst such as a metal oxide, and a homogeneous catalyst such as inorganic acids can be used. Moreover, organic solvents, such as acetone, water etc. can be used for a solvent. As the oxidizing agent, inorganic oxides such as hydrogen peroxide and metallized oxides, and organic oxides such as methyl hydroperoxide can be used.
This method can be used before and after the step of concentrating the cumene oxidation product obtained by the oxidation reaction of cumene, and can also be used when the product is subjected to a CHP decomposition reaction without concentration. It is.
[0021]
For example, a method of reducing dimethylphenylcarbinol with a specific reducing agent in the presence or absence of a specific metal catalyst to form cumene can be used.
As the metal catalyst, a noble metal catalyst in which a noble metal such as Pt or Ru is supported on a support such as silica or carbon, or an alloy catalyst such as Raney nickel or Raney copper can be used. Moreover, hydrogen, carbon monoxide, etc. can be used for a reducing agent.
[0022]
As a method of physically separating, for example, a method of selectively extracting and separating dimethylphenyl carbinol using a specific extractant can be used.
Further, for example, a method of distilling with a highly efficient distillation column can be used.
[0023]
  As a method combining chemical treatment and physical separation, for example, CHP in cumene oxide is reacted with an aqueous solution of an alkali metal hydroxide or an aqueous solution of an alkaline earth metal hydroxide to form a salt as an aqueous phase. Extract the water phaseInorganic acidsA method of obtaining the cumene oxidation product by the distillation operation as described above after neutralization with CHP can be used. Sodium hydroxide, potassium hydroxide, calcium hydroxide, and the like can be used as the alkali metal hydroxide and alkaline earth metal hydroxide here, but are not particularly limited. Sodium hydroxide is preferred because it is easily and inexpensively available. As will be described in detail later, when cumene oxide is obtained by this method, if salt remains in the cumene oxidation product, it is concentrated to neutralize inorganic acids and inhibit CHP acid decomposition reaction. It is preferred to remove to trace amounts previously.
[0024]
Cumene oxidation products obtained by these methods are CHP (60-90 wt%), dimethylphenyl carbinol (0-5 wt%), cumene (10-40 wt%), acetophenone (0-2 wt%). In addition, it has a component composition such as a small amount of dicumyl peroxide.
[0025]
The case where the method of the present invention is carried out in a two-stage reaction will be described in detail below.
First, the concentration of inorganic acids used in the first stage reaction with respect to the cumene oxidation product is said to exhibit high activity in a lower concentration range than the usual concentration range (100 to 500 ppm by weight), In general, in the process of producing phenol, acetone and α-MS from CHP, acid fluctuations affect the operational stability, so if the concentration is too low, the concentration of water in the reaction solution increases and the cumene oxidation product which is the raw material Under the influence of the sodium salt entrained therein, the acid strength and acid concentration may decrease, and unreacted CHP may increase. The acid decomposition reaction of CHP has a very fast reaction rate of half a second or less, and the heat of decomposition reaction generated is several times that of a general exothermic organic chemical reaction. For this reason, if several percent of CHP instantaneously undergoes a decomposition reaction due to fluctuations in reaction conditions, the temperature of the reaction mixture may rise rapidly, leading to a reactor burst. In addition, it is not preferable to carry out the reaction at an excessively high concentration because the reaction of increasing the α-MS produced is promoted. Therefore, the concentration of the inorganic acid to be used is not particularly limited, but a preferable range is 20 to 300 ppm by weight in view of the above-described influence.
In addition, the CHP conversion rate in the first stage reaction is preferably as high as possible. When the reaction is performed at a low conversion rate, the reaction temperature in the second stage reaction is remarkably increased, and the active ingredient α-MS This is not only unfavorable, but also a problem in the safe operation of the plant. Therefore, it is at least 95% or more and up to 99.9%, preferably 97 to 99.6%.
[0026]
Next, the reaction temperature in the first stage reactor is in the range of 55 to 90 ° C, preferably 55 to 85 ° C. The reaction temperature can be adjusted by cooling and condensing the evaporated acetone and circulating it. When this reaction temperature is higher than 90 ° C., unless the dimethylphenylcarbinol in the cumene oxide as a raw material is removed, the α-MS heavyization reaction is accelerated, and the target product phenol and The yield of acetone is reduced. On the other hand, a temperature of less than 55 ° C. is not preferable because a large amount of equipment is required for removing reaction heat and the stability of the temperature during the acid decomposition reaction is deteriorated.
[0027]
In the method of the present invention, cumylphenol or methylstyrene dimer and a high-boiling compound in which they are heavier are also produced from α-MS in the first stage reaction. In order to suppress this reaction, acetone can be added to lower the α-MS concentration in the reactor to suppress the α-MS heavier reaction, and the addition of acetone is not necessary in the reaction mixture. The acetone concentration is 20 to 70% by weight, and the yield of phenol and α-MS can be prevented from decreasing.
[0028]
Here, when the addition amount of acetone is more than 70% by weight, the α-MS heavyization reaction can be suppressed, but it is necessary to increase the amount of acetone circulating between the reactor and the acetone distillation equipment, As a result, a large amount of energy is required to distill acetone, and the demerit is greater in the entire process. In addition, when the amount of acetone added is less than 35% by weight, the effect of suppressing the α-MS heavy reaction is hardly obtained.
[0029]
For reference, Japanese Patent Application Laid-Open No. 9-20699 describes that in the method of adding acetone to the first stage reaction in a sulfuric acid catalyst, the production of HA increases and the quality deteriorates. In the method of the present invention, the concentration of inorganic acids to be used is kept low, and the water concentration in the acetone to be recycled is kept lower than the concentration range usually referred to, so that the decomposition rate of CHP is higher than the byproduct rate of HA. The increase in hydroxyacetone due to excess acetone is not observed.
[0030]
The residence time of the reaction mixture in the first stage reactor is in the range of 5 to 40 minutes, and is usually adjusted to be about 15 to 30 minutes.
In the first stage reaction, the reaction heat generated when phenol and acetone are produced by the acid decomposition of CHP is several times the amount of reaction heat in a general organic chemical reaction. Therefore, in the reaction in the first stage, the generated heat of reaction is completely removed and maintained at a predetermined reaction temperature, so that the decomposition rate of CHP is made constant. From the first stage reactor, the component composition is stabilized. The reaction temperature must be controlled so that the reaction mixture can be supplied to the second stage reactor.
[0031]
As a type of the reactor that can easily control the temperature, a complete mixing tank reactor is preferable. In addition, for example, a system having a cooling pipe inside the reactor, a system having a jacket for flowing a refrigerant around the outer periphery of the reactor, and removing reaction heat using latent heat of vaporization of acetone co-produced during the reaction. A method etc. can be adopted. The reaction can also be carried out by a reactive distillation system in which the reaction heat is removed and the produced acetone is separated at the same time. At this time, acetone generated in the reaction used for temperature control of the reactor is evaporated by the heat of reaction and extracted from the top of the distillation column attached to the top of the reactor. In this case, the reaction temperature is adjusted by the tower top pressure and the reflux ratio of acetone. Accordingly, it is necessary to select appropriate conditions for the reaction pressure from the range of reduced pressure, normal pressure, and increased pressure depending on the composition of the reactants and the reaction temperature.
[0032]
By performing the first stage reaction by the above method, dimethylphenylcarbinol in the cumene oxidation product as a raw material is converted into dicumyl peroxide as a reaction product with CHP, or in an unreacted state. Present in the reaction mixture, conversion to α-MS, and further to high boilers is suppressed. The reaction mixture thus obtained from the first stage reactor is mainly composed of phenol, acetone, dimethylphenyl carbinol, dicumyl peroxide and cumene, and is continuously supplied to the second stage reactor.
[0033]
Next, in the second stage reaction, a reaction for producing α-MS mainly from dimethylphenylcarbinol or dicumyl peroxide in the reaction mixture is performed. Since the α-MS production reaction is an exothermic reaction, the temperature at the outlet is higher than the temperature at the reactor inlet, and the temperature difference varies depending on the amount of dicumyl peroxide to be reacted. Therefore, it is necessary to control the outlet temperature of the second stage reactor.
In addition, since the reaction rate increases when the reaction temperature is high, it is necessary to perform control such as shortening the reaction time. From these facts, the reaction temperature in the second stage reactor is 55 to 120 ° C, and preferably the temperature from the second stage reactor to less than 120 ° C. When the reaction temperature of the second stage reactor exceeds 120 ° C. and the conversion rate from dicumyl peroxide and dimethylphenylcarbinol to α-MS is 70% or more, cumyl which is a heavy product of α-MS Since the byproduct rate of phenol, methylstyrene dimer and high boiling point compound increases rapidly, it is not preferable.
From these, as the second-stage reactor, a plug flow reactor that can lengthen the column length with respect to the inner diameter or provide a baffle plate inside the reactor to suppress back mixing of the reaction mixture is preferable. Used. The residence time of the reaction mixture in this second stage reactor is usually about 0.1 to 60 minutes, preferably about 0.5 to 30 minutes. The reaction pressure may be any of reduced pressure, normal pressure, and increased pressure.
[0034]
Furthermore, in the second-stage reactor, the reaction product is cooled immediately after the α-MS formation reaction from dicumyl peroxide and dimethylphenylcarbinol is completed, and neutralization treatment of inorganic acids as acid catalysts is performed. It is necessary to stop the reaction. This is because when an acid catalyst is present in the reaction product, even when the decomposition reaction of the organic peroxide (such as CHP) is completed, the α-MS is made heavy, that is, cumylphenol, methylstyrene dimer, Furthermore, the formation reaction of the highly boiling compound proceeds, and the yield of α-MS and phenol deteriorates.
Here, the neutralization treatment of inorganic acids which are acid catalysts in the reaction mixture is usually performed using an aqueous sodium hydroxide solution, sodium phenolate which is a salt of sodium hydroxide and phenol, or an aqueous sodium carbonate solution.
[0035]
In the method of the present invention, the reaction product after neutralization is separated into acetone, phenol, α-MS, cumene and the like in the distillation step. At this time, a part of the separated acetone can be circulated and used as a supply solvent for the reaction diluent and inorganic acids to the first stage reactor.
[0036]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited at all by the following example.
[0037]
  Comparative Example 3
  Cumene is oxidized in air at 100 ° C. and concentrated to produce a cumene oxidation product (composition is CHP 82.9 wt%, dimethylphenyl carbinol 4.5 wt%, acetophenone 0.5 wt%, cumene 10.7 wt%). Obtained. The sodium salt concentration in the cumene oxidation product was 2.8 ppm by weight, and the organic acid concentration was 220 ppm by weight.
  The cumene oxidation product thus obtained is supplied to a continuous complete mixing tank reactor having a heat removal function as a first stage reactor to perform a CHP decomposition reaction, and subsequently as a second stage reactor. The α-MS production reaction was mainly carried out using an adiabatic plug flow reactor.
[0038]
First, 225 g / hr of cumene oxidation product and acetone containing 800 ppm by weight of sulfuric acid (concentration in the reaction solution as 200 ppm by weight) as a catalyst were continuously supplied to the first stage reactor by a pump at 75 g / hr. The reaction temperature was controlled at 78 ° C. by cooling, condensing, and refluxing acetone evaporated in the reactor under normal pressure, thereby obtaining a reaction mixture. The volume of the first stage reactor was 100 ml, and the residence time in the reactor at this time was 17 minutes. Here, acetone supplied together with the catalyst was distilled and separated from the reaction product of the second stage described later, and contained 1000 ppm by weight of aldehydes having a lower boiling point than acetone and 3.0% by weight of water. It was a thing. The water concentration in the reaction mixture was 1.2% by weight.
[0039]
A portion of the resulting reaction mixture was taken for analysis, cooled and neutralized with 20 wt% aqueous sodium carbonate. As a result of analyzing the neutralized reaction solution by gas chromatography, the acetone concentration was 47.1% by weight, the CHP conversion was 99.5%, and the dimethylphenylcarbinol conversion was 85.2%.
[0040]
Next, the reaction mixture distilled from the first-stage reactor was supplied to an adiabatic plug flow reactor heated and heated in advance to carry out the second-stage reaction. The volume of the second stage reactor was 6 ml, the residence time of the reaction mixture in the reactor at this time was 1 minute, and the outlet temperature of the reactor was 118 ° C. The reaction product thus obtained was immediately cooled and neutralized with a 20 wt% aqueous sodium carbonate solution to stop the reaction. This reaction product was analyzed, and the amount of high boiling impurities FO and HA per unit phenol production amount was determined. The results are shown in Table 1.
[0041]
  Reference example 1
  Cumene is oxidized by air under the conditions of 100 ° C. and CHP concentration in the reaction vessel of 15% by weight, and concentrated to produce a cumene oxidation product (composition is 83.0% by weight of CHP, 2.5% by weight of dimethylphenyl carbinol, 0.4 wt%, cumene 12.7 wt%). The same procedure as in Comparative Example 3 was performed except that the cumene oxidation product thus obtained was used as a raw material. The results are shown in Table 1.
[0042]
  Example 3
  Cumene oxidation product obtained by subjecting cumene to air oxidation at 115 ° C. and concentration was converted into dimethylphenylcarbinol and equimolar hydrogen peroxide in the cumene oxidation product.TheWater was added to 5 wt% sulfuric acid so that the ratio of oil to water was 1, and reacted at 60 ° C., then the separated and recovered oil phase was concentrated, and cumene oxidation product (composition was CHP 83.4 wt. %, Dimethylphenyl carbinol 2.4% by weight, acetophenone 0.5% by weight, cumene 12.5% by weight). Other than using the cumene oxidation product thus obtained as a raw material,Comparative Example 3As well as. The results are shown in Table 1.
[0043]
Example 4
The cumene oxidation product obtained by air-oxidizing and condensing cumene at 115 ° C. is reacted with CHP in the cumene oxidation product and a stoichiometric amount of aqueous sodium hydroxide solution to recover the aqueous phase to obtain an aqueous CHP sodium salt solution. It was. Cumene was added to this CHP sodium salt aqueous solution so that the ratio of oil to water was 1, neutralized with sulfuric acid, the oil phase recovered by separation was concentrated, and the cumene oxidation product (composition was CHP 83.4% by weight, dimethylphenylcarbyl). Nool 0.4 wt%, acetophenone 0.1 wt%, cumene 15.0 wt%). The sodium salt concentration of this cumene oxidation product was 0 ppm by weight, and the organic acid concentration was 20 ppm by weight.
[0044]
  The cumene oxidation product thus obtained isComparative Example 3Similarly, acetone containing 225 g / hr and 1840 ppm by weight of sulfuric acid (40 ppm by weight as the concentration in the reaction solution) as a catalyst was continuously supplied to the first stage reactor by a pump at 5 g / hr. The reaction temperature was controlled at 90 ° C. by cooling, condensing, and refluxing acetone evaporated in the reactor at normal pressure, thereby obtaining a reaction mixture. The residence time in the reactor at this time was 22 minutes. Here, acetone supplied with the catalyst isComparative Example 3Similarly, the aldehydes having a boiling point lower than that of acetone were 1000 ppm by weight and water was 3.0% by weight. The acetone concentration in the reaction mixture was 33.2% by weight, and the water concentration was 0.3% by weight.
  The resulting reaction mixture was collected for analysis, cooled and neutralized with 20 wt% aqueous sodium carbonate. As a result of analyzing the neutralized reaction solution by gas chromatography, the CHP conversion rate was 99.9%, and the dimethylphenyl carbinol conversion rate was 88.5%. The second stage reaction was not performed. The results are shown in Table 1.
[0045]
  Comparative Example 1
  Cumene is oxidized by air at 115 ° C. and concentrated to obtain a cumene oxidation product (composition: CHP 83.1 wt%, dimethylphenyl carbinol 6.6 wt%, acetophenone 0.9 wt%, cumene 7.7 wt%). Obtained. The sodium salt concentration in the cumene oxidation product was 3.6 ppm by weight, and the organic acid concentration was 300 ppm by weight. Other than using the cumene oxidation product thus obtained as a raw material,Comparative Example 3As well as. The results are shown in Table 1.
[0046]
  Comparative Example 2
  Dimethylphenylcarbinol reagent (2-phenyl-2-propanol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the cumene oxidation product obtained by subjecting cumene to air oxidation at 115 ° C. and concentration, and a prepared cumene oxidation product (composition was CHP82. 1% by weight, dimethylphenyl carbinol 9.5% by weight, acetophenone 0.8% by weight, cumene 5.9% by weight). Other than using the prepared cumene oxidation product thus obtained as a raw material,Comparative Example 3As well as. The results are shown in Table 1.
[0047]
[Table 1]

* C'nol: Dimethylphenyl carbinol
* F. O. : Dicumyl peroxide, cumylphenol,
            Methylstyrene dimer, H.P. B. Addition of (high boiling point compounds)
* HA: Hydroxyacetone
* Kg / t-Ph: Production amount per 1t of phenol (kg)
[0048]
【The invention's effect】
In the decomposition reaction of cumene oxidation product mainly composed of cumene hydroperoxide and the formation reaction of α-methylstyrene in the presence of an inorganic acid catalyst, the concentration of dimethylphenylcarbinol contained in the cumene oxidation product is 5 By adjusting it to be less than wt%, it is possible to suppress the production of high-boiling compounds that cause the deterioration of the yield of phenol and α-MS and the production of hydroxyacetone that deteriorates the quality of the product phenol. It is superior.

Claims (9)

In a method for producing phenol, acetone and α-methylstyrene by decomposing a cumene hydroperoxide-based cumene oxidation product with inorganic acids, a cumene oxidation product to be supplied (cumene hydroperoxide content: 60 to 90 wt. %) In which the concentration of dimethylphenylcarbinol is 3% by weight or less by one or more of the following methods (b) and (c).
(B) Dimethylphenylcarbinol contained in the cumene oxidation product is converted to cumene hydroperoxide by an oxidizing agent that is an inorganic peroxide or an organic peroxide to reduce the dimethylphenylcarbinol concentration to 3% by weight or less. (C) A solution of cumene hydroperoxide obtained by reacting an aqueous solution of an alkali metal hydroxide or an alkaline earth metal hydroxide with cumene hydroperoxide in the cumene oxidation product in an aqueous phase. Extraction and separation, and neutralizing the aqueous phase with inorganic acids In a method for producing phenol, acetone and α-methylstyrene by decomposing a cumene hydroperoxide-based cumene oxidation product with inorganic acids, a cumene oxidation product to be supplied (cumene hydroperoxide content: 60 to 90 wt. %) In which the concentration of dimethylphenyl carbinol contained is 3% by weight or less by the following method (c).
(C) Extracting and separating a cumene hydroperoxide salt obtained by reacting an aqueous solution of an alkali metal hydroxide or an alkaline earth metal hydroxide with cumene hydroperoxide in the cumene oxidation product into an aqueous phase. And neutralizing the aqueous phase with inorganic acids   The reaction temperature is in the range of 55 to 90 ° C., the acetone concentration in the reaction mixture is in the range of 20 to 70% by weight, and the conversion of cumene hydroperoxide is performed to 95 to 99.9%. The manufacturing method according to claim 1 or 2.   In the method of producing a phenol, acetone and α-methylstyrene by a two-stage reaction by decomposing a cumene oxidation product (cumene hydroperoxide content: 60 to 90% by weight) based on cumene hydroperoxide with inorganic acids. A process for producing phenol, wherein the first stage reaction is carried out by the method according to claim 3 and then the reaction is completed in a second stage reactor having a reaction temperature of 55 to 120 ° C.   The production method according to claim 3 or 4, wherein the acetone evaporated in the reactor is cooled, condensed, and refluxed to maintain the reaction temperature at 55 to 90 ° C.   The production method according to claim 3 or 4, wherein a part of the acetone separated from the reaction product leaving the reactor is circulated to the reactor.   The production method according to claim 6, wherein the water concentration in acetone separated from the reaction product leaving the reactor is controlled to 4 wt% or less and circulated in the reactor.   In a method for producing a phenol, acetone and α-methylstyrene by decomposing a cumene oxidation product mainly composed of cumene hydroperoxide with an inorganic acid, the inorganic acid is a homogeneous acid catalyst, and the concentration in the reaction solution is 20 The production method according to any one of claims 1 to 7, wherein ˜300 ppm by weight is used.   The production method according to claim 1 or 2, wherein the reaction product exiting the reactor is immediately cooled and neutralized to stop the reaction.