KR830001166B1 - Process for preparing phenolic compound - Google Patents

Abstract

None.

Description

Process for preparing phenolic compound

Process flow diagram showing an embodiment of the method according to the invention.

The present invention relates to a method for preparing a phenolic compound. More particularly, the present invention relates to a process for industrially advantageously preparing phenolic compounds in pure form by catalytic acid decomposition of aralkyl hydroperoxides such as cumenehydroperoxides.

The phenolic compound is industrially produced by catalytic acid decomposition of an aralkylhydroperoxide represented by the following general formula (I) or (II).

(Wherein Ar represents a phenyl ring. R ₁ , R ₂ , R ₃ , and R ₄ independently represent a lower alkyl group as a group)

For example, phenols are prepared by contacting cumene hydroperoxide obtained by air oxidation of cumene with an acid such as sulfuric acid to break down cumene hydroperoxide into phenol and acetone and then to separate the phenol from the acid decomposition product.

Among the catalytic acidification products of cumene hydroperoxides are many different impurities, such as salts of acids used for acid decomposition; ethylbenzene and / or p-diisopropylbenzene in raw cumene; unreacted cumene air; In addition to acetophenone, phenyldimethylcarbinol, mesityloxide and hydroxy acetone, which are by-products of the oxidation and catalytic acid decomposition of cumulative peroxide, and phenol and acetone, the main reaction products, 2-methyl- Benzofuran, 2,3-dimentylbenzofuran, and other high boiling by-products. These impurities cannot be completely removed by the fractionation type operation.

As a method for refining crude phenol by the above method, neutralization of acid in an acid decomposition product produced by catalytic cracking of cumenehydroperoxide with an acid, and fractionation of unreacted acetone, reaction solvent with low boiling point expansion, and water After removal by distillation, the residue is distilled as necessary to produce a high boiling point by-product of at least phenol, and the resulting crude phenol is extracted and distilled in the presence of polyalkylene glycol or ether thereof having a higher boiling point than at least phenol. A method for producing a purified phenol characterized by the swelling is described in Japanese Patent Publication No. 5713/61.

Although the method for purifying crude phenol by extractive distillation described in Japanese Patent Publication No. 5713/61 described above is one of the industrially employable refining methods, it still has a problem to be solved. It is not seen. For example, phenols produced by this method contain impurities that cause undesirable coloration when treated with chlorine or sulfonated with sulfuric acid and converted to useful materials for industrial spatula. Industrial applications are limited to the use of phenol derivatives, especially waste phenols, which require high purity as raw materials. Furthermore, in the case of regenerating and using an extractive distillation solvent, the above-described phenol has adverse effects such as lowering the quality of polyalkylene glycool or ether thereof used in the extractive distillation operation depending on the type of impurities.

A method for solving the above-mentioned problem is proposed in Japanese Patent Publication No. 1258/75, which comprises acetone from an acid decomposition product before extraction and distillation of the crude phenol with polyalkylene glycool or ether thereof. The low boiling point impurities are removed by distillation, and the remaining oil is adjusted so that the unreacted cumene content is 0.2 to 1.2 parts by weight and the water content is 0.2 to 1.2 parts by weight based on the phenol parts by weight, and then distillation of the oil is carried out under reduced pressure. The crude phenol obtained from the bottom of the column where water and cumene containing water and cumene are removed from the distillation column by preliminary removal of a portion of the above-mentioned impurities is introduced into an extractive distillation column, and fractionated in the presence of polyalkylene glycol or an ether thereof. Distillation is carried out to remove impurities contained in the crude phenol, and then high-purity phenol is converted into phenol and polyalkylene glycol or Characterized by Sikkim mixture and separating of the salt.

This improved method has been recognized as an effective method for practical industrial operation but must be removed beforehand with acetone and low non-oil content, and is only effective if cumulative amounts of cumene are contained in the acid decomposition products. The same cannot be applied to all methods as in the production of phenol by the men's method.

An object of the present invention is to provide a method for producing an phenolic compound which can produce a high-purity phenolic compound in high yield and solves the drawbacks in the above known methods.

The objects and effects of the bullet of the present invention will become apparent from the following description.

According to the present invention, an operation of catalytically decomposing aralkyl hydroperoxide with an acid to produce a phenol compound, an operation of recovering a crude phenol compound by removing by-products or impurities having a boiling point below and / or more than the acid and the resulting phenol compound A crude phenol compound is introduced into an extractive distillation column, followed by extractive distillation in the presence of a polyalkylene glycool or ether thereof having a boiling point above that of the phenolic compound to separate the phenolic compound from the column bottom fraction, polyalkyleneglycool or ether thereof. (B) an extraction distillation operation is performed such that the phenolic compound from the tower unit is released in an amount of 0.3 to 30% by weight based on the total weight of the phenolic compound in the crude phenolic compound introduced into the extraction column. Wastenol compound produced by steam distillation (B) recycling the bottoms liquid fraction containing the bottoms liquid fraction to an operation after the catalytic acid decomposition operation and before the extraction distillation operation, and separating the column bottoms fraction into a phenol compound, a polyalkylene glycol, or an ether thereof; Provided is a method for producing a phenolic compound, characterized in that consisting of.

In the first operation of the present invention, catalytic acid decomposition of aralkylhydroperoxide is performed. Aralkylhydro hydroxides are generally prepared by air oxidation of alkyl benzenes such as cumene, m-cymene, p-cymene, m-diisopropylbenzene and P-diisopropylbenzene by the conventional method. Or the compound represented by (II). Examples of the aralkylhydroperoxides include cumene hydroperoxide, m-cymenhydro peroxide, p-cymenhydro peroxide, p-diisopropylbenzenehydro peroxide, H-diisopropylbenzenehydro peroxide and the like. In the process of the present invention, it is preferable to use cumene hydroperoxide, m-cymenhydro peroxide and p-cymenhydro peroxide, and particularly preferably cumene hydroperoxide.

Aralkylhydro peroxide is contacted with an acid or strong acid type ion exchange resin such as sulfuric acid, hydrochloric acid, silica-alumina solid acid or the like to decompose into a phenol compound and a ketone by a known method known as a decomposition reaction. For example, phenol and acetone from cumene hydroperoxide, m-cresol and acetone from H-cymenhydro peroxide, p-cresol and acetone from p-cymenhydro peroxide, hydroquinone and acetone from P-isopropylbenzenehydro peroxide and Resorcinol and acetone are prepared from m-diisopropyl benzenehydro peroxide.

The catalytic acid decomposition product contains various by-products and impurities depending on the kind of aralkyl hydroperoxide or acid used in addition to the desired phenol compound, the contact conditions, and the like. Among the decomposition products of cumene hydroperoxides with sulfuric acid, for example, are sulfuric acid, solvents used for catalytic acid decomposition operations (e.g. cumene), mesityl oxoxide, hydroxy acetone, 2-methylbenzofuran, 2,3-dimethylbenzofuran, acet In addition to aldehydes, propion aldehydes, isobutyr aldehydes, α-methylstyrene, acetophenones, pentyldimethylcarbinol and the main products phenol and acetone, other high boiling compounds of unknown structure, which are house products or impurities, will be contained.

Prior to the extractive distillation operation, the crude acid decomposition product is recovered by performing the removal operation of the by-products having a boiling point below and / or above the acid and the spent phenolic compound.

The above-mentioned recovery operation of the phenolol compound can be performed by a conventional method. As a typical method of such a recovery operation, the catalytic acid decomposition product is neutralized with sodium hydroxide and / or sodium phenolite to remove salts generated, distillation removes ketones such as acetone, and then the crude phenol compound is removed. Enumerate the distillation bottoms of the resulting distillate bottom liquid to remove the high boiling point compound that is distilled and distilled column bottom liquid to remove most components (eg, water, cumene and α-methylstyrene) having a lower boiling point than the phenol compound. I can do it

The crude phenol compound thus recovered depends on the method employed in the recovery operation, but generally contains about 95% by weight or more, usually 97 to 99.5% by weight of phenolic compounds and impurities having the following composition ratio.

About 70 to 90% by weight of low boiling hydrocarbons such as cumene and α-methylstyrene

High boiling hydrocarbons such as 2-methylbenzofuran and 2,3-dimethylbenzofuran: about 5 to 20% by weight

Ketones such as acetophenone, mesityl oxide and hydroxy acetone: about 5 to 15% by weight

The crude phenolic compound having the above composition is then introduced into an extraction distillation column where it is extracted and distilled in the presence of polyalkyleneglycool or ether thereof.

The polyalkylene glycools or ethers thereof used for extractive distillation have a boiling point above the phenolic compound in the crude phenolic compound, and preferably has a boiling point of 20 ° C. or higher than the phenolic compound.

In general, it is preferable to use polyalkylene glycols or ethers thereof represented by the following general formula (I).

R ₅ -O-(-R ₆ -O-)-nR ₇ (I)

(Wherein R ₅ and R ₇ are the same or different and each represent a hydrogen atom or a lower alkyl group, R ₆ represents a lower alkylene group and n is an integer of 1 to 4, in particular an integer of 1 to 3).

As used herein, the term "lower" as used for limiting a group or compound means a group or compound having 6 or less carbon atoms, preferably 4 or less carbon atoms.

In the general formula, lower alkyl groups may be exemplified by methyl, ethyl, n or i-propyl and n-, i-, second or tertiary butyl, and examples of lower alkylene groups include ethylene, propylene, 1,2 -Propylene and 2,2-dimethylpropylene.

Examples of preferred polyalkylene glycols or ethers thereof include polyalkylene glycols such as diethylene glycol, triethylene glycol and dipropylene glycol, and diethylene glycol methyl ether, diethylene glycol ethyl ether, and diethylene. Polyalkylene glycol ethers, such as a glycol propyl ether and diethylene glycol butyl ether, can be mentioned. You may use these individually or in mixture of the above. The amount of the polyalkylene glycool or ether thereof is not very important, but varies depending on the type and content of impurities in the crude phenol compound to be introduced and the quality (purity) of the desired phenolic compound. About 0.1 to about 10 parts by weight, preferably about 0.5 to about 5 parts by weight, based on the weight of the phenol compound.

The extraction operation of the crude phenol compound can be carried out by its own known method (for example, refer to Japanese Patent Publication No. 5713/61). For example, the operation conditions in the distillation operation in an extraction distillation column are selected according to the kind of polyalkylene glycol, an ether, etc. which are extraction solvents. Extractive distillation is generally carried out at atmospheric pressure or at a reduced pressure of up to about 10 mmHg (absolute pressure).

The distillation column bottom temperature is preferably set to a temperature at which no decomposition of polyalkylene glycol or ethers thereof occurs, such as 200 ° C. or lower when using diethylene glycol.

In extractive distillation, the polyalkylene glycol or ether thereof is preferably introduced at the stage at the top of which the crude phenol compound is introduced into the distillation column.

In the improved process of the present invention, the extractive distillation operation is characterized in that the phenolic compound from the top portion is 0.3 to 30% by weight, preferably 0.5 to 25% by weight relative to the total weight of the phenolic compound in the crude phenolic compound. More preferably it is important to carry out under conditions that are released in an amount of 1 to 20% by weight.

When the extraction distillation operation is performed under the above-mentioned conditions, unnecessary impurities contained in the crude phenol compound are removed together with the phenol compound as the top refined oil. On the other hand, an oil composed of a phenol compound and polyalkylene glycol or an ether thereof and containing no impurities, especially colored impurities, can be obtained as a bottom oil.

In the extractive distillation, an operation method for distilling the phenolic compound into the above phenolic compound introduced into the top refined oil in an amount within the above range is a known method for those skilled in the art.

In the extractive distillation operation in the method of the present invention, the operation is performed such that the amount of distillation of the phenolic compound in the crude phenol compound introduced into the extractive distillation column is 0.3 to 30% by weight from the tower portion. The extraction distillation operation should preferably be adjusted so that the concentration of the phenolic compound in the overhead refinery is generally at least 10% by weight, preferably at least 20% by weight.

The bottoms fraction of the extraction distillation column operated under the above-mentioned conditions is substantially free of impurities, especially colored impurities, and is substantially composed of the phenolic compound polyalkylene glycool or an ether thereof. The bottom oil can be separated into a top bottom oil composed of a high quality purified phenolic compound and a top bottom fraction composed of a polyalkylene glycol or an ether thereof and a small amount of a phenolic compound introduced by a simple commercial distillation operation. This bottom fraction can be recycled into the extraction distillation column.

Since the column top fraction from the extractive distillation column containing the phenol compound and the impurities contains a significant amount of the phenol compound, steam distillation is performed to perform a recovery operation. Most of the spentol compound is recovered to the bottom liquid of the steam distillation operation, and the oil-rich oil content thus recovered is recycled to the operation after the catalytic acid decomposition operation of the aralkylhydroperoxide and before the extraction distillation operation. The use of steam distillation to recover the recycled phenolic compound is the most reasonable for recovering the phenolic compound, which is another important feature of the improved process of the present invention.

When the steam distillation operation is performed, the phenolic compound is effectively recovered, and a high quality phenolic compound is obtained by releasing a significant amount of impurities in the crude phenolic compound introduced in the extractive distillation operation to the outside of the phenol production system and preventing accumulation of impurities in the crab. Thus, steam distillation operation results in the extraction of the distillation tower refinery components other than the phenolic compounds (ie, at least about 20% by weight, preferably at least about 50% by weight, most preferably at least about 70% by weight of impurities) into the top refinery, It is preferred to perform the operation such that at least about 50%, preferably at least about 70%, and more preferably at least about 90% by weight of the phenolic compounds in the extractive distillate are collected into the bottom oil.

Although the distillation operation in the steam distillation column varies depending on the type of phenolic compound, it is preferable that the distillation operation is performed at atmospheric pressure or at a pressure of up to about 100 mmHg (absolute pressure) when the phenolic compound in the oil is phenol or cresol. .

The amount of water used for steam distillation is not critical, but is generally about 0.05 to about 2.0 parts by weight, preferably about 0.1 to about 2.0 parts by weight, based on the weight of the tower oil from the extractive distillation column.

The column top fraction of the steam distillation is carried out in a conventional manner to separate the oil and water. The oil layer containing no wasteol compound is removed out of the system, and the water layer is recycled to the steam distillation column. The amount of water layer to be recycled is preferably about 0.5 to about 3.0 parts by weight based on the weight part of the export distillation column top fraction.

The top fraction of the steam distillation column mainly contains phenolic compounds and water, and contains a small amount of impurities. This fraction is recycled to either operation after catalytic acid decomposition operation of aralkylhydroperoxide and before extraction distillation operation. If there is a neutralization operation between these operations, it is preferable to recycle the oil to the neutralization operation. This operation is not limited to the neutralization operation, and when fractional distillation is employed to remove by-products or impurities with boiling points below and / or above the resulting phenolic compounds, this fraction is of course recycled to one or more distillation columns during the fractional distillation operation. You can.

The bottom liquid amount of the steam distillation column to be recycled is not critical and can vary widely depending on the operating conditions in the extraction distillation operation and / or the steam distillation operation. In general, all the bottom liquid fractions are recycled, and the amount thereof is about 1 to about I5 parts by weight based on 100 parts by weight of the phenol compound contained in the acid decomposition product.

Various methods may be employed to recover the phenolic compound from the column top fraction of the extractive distillation column. For example, a method of using alkali such as sodium hydroxide is not an industrially suitable method because an excess of alkali is required.

Separation distillation, which is commonly used to separate phenolic compounds from impurities that can degrade the quality of phenolic compounds, makes it difficult to separate them.In case of recycling the recovered phenolic compounds, impurities are gradually accumulated to obtain high quality phenolic compounds. You can't get it in yield. Another drawback is that due to the circulation of impurities accumulated in the system, the loss of thermal energy is significantly increased. By adopting the steam distillation method according to the method of the present invention, it is possible to effectively reuse the phenolic compound recovered from the effectively separated impurities as a recycle filler.

According to an improved process for the preparation of phenolic compounds of the invention, by-products or impurities in the extractive distillation of the crude phenolic compounds with polyalkyrene glycols or ethers thereof are removed together with a fairly small amount of phenolic compounds as the top fraction of the extractive distillation column.

Therefore, a considerable amount of purified phenolic compounds separated from the bottom fraction of the extraction distillation column can be obtained as high purity products. In addition, according to the method of the present invention, since the phenolic compound-containing fraction recovered by steam distillation of the column top fraction of the extractive distillation column is recycled to the crude wasteol compound before introduction into the extractive distillation column, the total recovery rate of the phenolic compound is not reduced. In addition, the method of the present invention is very rational and economical in view of the industrial operation because only the operation of recovering the phenol compound-containing fraction by fractional distillation of the column top fraction of the extraction distillation column and steam distillation of the column top fraction is performed as an additional operation. It is phosphorus processing method. Moreover, the method of this invention has the effect that an extraction solvent does not deteriorate even if it is industrially operated for one year or more.

As described above, the method of the present invention is characterized by the combination of the extraction distillation operation and the steam distillation operation in the extraction distillation column under the above-mentioned conditions for recovering the oil rich in phenolic compound content from the tower top fraction of the extraction distillation column. By using these operations together, a high purity phenolic compound can be obtained in high yield. Moreover, all the ideal methods can be employ | adopted without any specific restriction | limiting in manufacturing crude phenolic compound. Therefore, the industrial effect of the present invention is very large.

The present invention will be described in more detail with reference to the following accompanying drawings, which are process distribution channels, in which parts and percentages refer to parts by weight and percentage by weight unless otherwise specified.

Example 1

Cumene (containing 99.8% purity, 0.1% ethylbenzene and 0.1% mixture of cymen and butyl benzene) was air oxidized at about 100 ° C. and unreacted cumene was distilled off. The reaction product containing about 80% by weight of cumenehydroperoxide was decomposed at about 80 ° C. in the presence of about 0.2% sulfuric acid relative to the weight of the reaction product to completely decompose the cumenehydroperoxide into phenol and acetone.

The catalytic acid decomposition products include about 36% phenol, about 45% acetone, about 14% low-boiling hydrocarbons (boiling point, below 170 ° C.) such as cumene and α-methylstyrene, and mesityl oxide, hydroxyacetone, unknown high boiling hydrocarbon, It was formulated with residual amounts of acetophenone, cumylphenol and sulfuric acid.

The acid decomposition product was also introduced into the tube with the phenolic tablet shown in FIG. More specifically, 288.66 parts of acid decomposition products were introduced into the neutralization tank 3 through the conduit 1 and 32.23 parts of sodium hydroxide aqueous solution was also introduced into the neutralization tank 3 through the conduit 2. 6.04 parts of aqueous sodium sulfate solution was discharged | emitted from the neutralization tank 3 through the conduit 4. In the meantime, the washed neutralization product of the acid decomposition product was transferred through the conduit 5 into the first distillation column 6 and fractionally distilled under atmospheric pressure in the first distillation column 6. Through conduit (7), low-boiling fractions are removed as a total of 201.51 parts, which are about 64% acetone, about 19% low-boiling hydrocarbons such as cumene and α-methylstyrene, about 16% water, and α-methylstyrene and hydroxide It was formulated with the remaining amount of the mixture with roxiacetone. The distillation column bottom fraction in the first distillation column (6) was transferred to the second distillation column (9) through a conduit (8), fractionated and distilled therefrom, and the high boiling fraction was separated at a column head pressure of 300 mmHg. 12.03 parts (about 50% total) of the bottom-floor fraction consisting of acetophenone and cumylphenol and a small amount of phenol and other compounds were discharged through the conduit (10).

The oil fraction distilled from the government of the second distillation column (9) is 104.09 parts of crude wasteol, 101.64 parts of crude phenol, about 1.91 parts of low boiling hydrocarbons such as cumene and α-methylstyrene, and high boiling hydrocarbons such as benzofuran and phenylhexene. About 0.25 parts and about 0.17 parts of ketones such as mesityl oxide and hydroxy acetone were prepared. The crude phenol is then transferred to the extraction distillation column 12 via conduit 11 and 233.32 parts of diethylene glycol alcohol containing about 23 parts of phenol introduced into the government of the distillation column 12 via conduit 13 as a solvent. Extractive distillation was carried out. The extraction distillation operation was performed under the tower top pressure of about 100 mmHg (absolute pressure), the tower top temperature 117 degreeC, and the tower bottom temperature 185 degreeC.

4.10 parts of tower top fractions are obtained from the extraction distillation column, which is 47.9% of low boiling point hydrocarbons such as cumene and α-methylstyrene, 6.9% of high boiling point hydrocarbons such as benzofuran and phenylhexane, hydroxyacetone and mesityl oxide, etc. And ketones of 5.1% and phenol 40.1% (equivalent to 1.64 parts). The bottom fraction of the extractive distillation column is 333.32 parts of the mixture of phenol and ethylene glycol. The mixture was transferred to a fractional distillation column 15 through a conduit 14 and distilled at a tower top pressure of 100 mmHg (absolute pressure) and a tower top temperature of 122 ° C.

As a result of the distillation operation in the fractionation column, diethylene glycol, a high boiling point fraction, was discharged through the conduit 13 in an amount of 233.32 parts (containing about 23 parts of phenol) and recycled to the extraction distillation column 12 as an extractive distillation solvent. The phenol product was recovered via conduit 16 as a low boiling fraction. The amount of phenol produced was 100 parts (recovery rate 96.2%) and its sulfonated coloring value as defined below was 94.

Sulfonation coloration value was measured as follows.

20 ml of phenol samples were heated for 10 minutes in a 45 ° C. hot bath and immediately mixed with 20 ml of concentrated sulfuric acid. The mixture was left at room temperature for 1 minute and in water for 5 minutes. The sample was transferred to a 20 ml cell and the light transmittance was measured at 532 mμ using a photochromic colorimeter and expressed in%. The greater the sulfonated coloring value, the better the purity of the phenol.

Since the low boiling point fraction obtained in the extraction distillation column contained 1.64 parts of phenol, phenol was distilled at a rate of 1.61 parts (1.64 / 101.64 × 100) based on 100 parts by weight of phenol contained in the crude phenol. This fraction was transferred to a steam distillation column 18 through a conduit 17, and steam distillation was carried out at a pressure of 300 mmHg (absolute pressure) of the distillation column, a column bottom temperature of 76 ° C, and a column bottom temperature of 82 ° C. In the operation of steam distillation, 1.08 parts of water were added via conduit 19 and 8.66 parts of the water layer from tower top effluent-separation tank 20 were recycled through conduit 21. An oil layer (2.39 parts) containing about 5.4% of phenol in addition to impurities as a main component was discharged from the separation tank through the conduit 22. On the other hand, the bottoms fraction of the steam distillation column contained 1.51 parts of phenol, 1.08 parts of water and 0.20 parts of impurity, which was recycled to the neutralization tank 3 through the conduit 23.

When the method was operated continuously for one year, the phenol purity could be maintained without decreasing the recovery rate of phenol, and no alteration of diethylene glycol was observed.

Comparative Example 1

Extractive distillation with diethylene glycol and fractional distillation of phenol from the extractive distillation solvent were carried out as in Example 1 and the differences from Example 1 are described below.

The amount of aqueous sodium hydroxide solution used for neutralization was 33.36 parts, the amount of washed neutralization product of the acid decomposition product was 315.98 parts, the low boiling point fraction in the first distillation column was 201.43 parts and the crude phenol amount was 102.52 parts (100.13 parts as phenol). These amounts were substantially the same as the corresponding amounts in Example 1.

The extraction distillation operation was carried out under a tower pressure of 100 mmHg (absolute pressure), a tower top temperature of 110 ° C. and a tower bottom temperature of 185 ° C. As a result, 252 parts of top-level fractions were obtained, which were about 78% of low boiling hydrocarbons such as cumene and α-methylstyrene, about 10% of high boiling hydrocarbons such as benzofuran and phenylhexane, and hydroxyacetone and mesityl oxide. It was composed of about 7% of ketones and about 5% of phenol. The phenol was distilled at a rate of 0.13 parts by weight (0.13 / 100.13 x 100) relative to 100 parts by weight of crude phenol.

The bottom fraction of the extractive distillation column was subjected to fractional distillation to obtain 100 parts of phenol product separated from diethylene glycol, but the sulfonated color value was only 58%.

Example 2

Cumene (purity 99.8%, 0.1% ethylbenzene and 0.1% cymen and butylbenzene mixture) was air oxidized at about 100 ° C. and unreacted cumene was distilled off. The reaction product containing about 80% cumene hydroperoxide was reacted. Acid decomposition was carried out at a temperature of about 80 ° C. in the presence of sulfuric acid of about 0.2% relative to the weight of and completely decomposed into cumenehydroperoxide phenol and acetone.

Catalytic acid decomposition products include about 36% phenol, about 45% acetone, about 14% low-boiling hydrocarbons (boiling point, below 170 ° C) such as cumene and α-methylstyrene, and high boiling points of mesityl oxide, hydroxyacetone and unknown Composition remaining amount with hydrocarbon, acetophenone cumylphenone and sulfuric acid.

The acid degradation product was introduced into the phenolic tablet conduit shown in FIG. In more detail, 288.57 parts of acid decomposition products were introduced into the neutralization tank 3 through the conduit 1, and 31.18 parts of the sodium hydroxide aqueous solution were introduced into the neutralization tank 3 through the conduit 2. 6.04 parts of sodium sulfate aqueous solution were discharged through the conduit (4). On the other hand, 325.65 parts of the washed neutralized product of the acid decomposition product was transferred to the first distillation column through the conduit (5), and fractional distillation was performed under atmospheric pressure in the first distillation column (6). Through the conduit (7), the low boiling fraction was removed in a total amount of 202.84 parts, which was about 64% acetone, about 20% low boiling hydrocarbons such as cumene and α-methylstyrene, about 16% water and mesityl oxide and It consisted of the remainder of the composition with hydrocyacetone. The distillation column bottoms liquid in the first distillation column (6) was transferred to the second distillation column (9) through a conduit (8), and fractional distillation was carried out under a column pressure of 300 mmHg to separate the high boiling fraction. Top bottom liquid fraction (11.85 parts) consisting of acetphenone and cumylphenol (about 50% in total) and a small amount of phenol and other compounds as main components was discharged through conduit 10.

The oil distilled from the second distillation tower (9) was 110.96 parts of crude phenol, which was 109.57 parts of phenol, about 0.59 parts of low boiling hydrocarbons such as cumene and α-methyl styrene, and high boiling hydrocarbons such as benzofuran and phenyl hexane. 0.30 parts and 0.50 parts of ketones such as mesityl oxide and hydroxyacetone. The crude phenol was transferred to the extraction distillation column 12 through the conduit 11, and 262 parts of diethylene glycol alcohol containing about 43 parts of phenol introduced into the column top of the distillation column 12 through the conduit 13 was used as a solvent. Extractive distillation was performed. The extractive distillation was operated under a column head pressure of about 100 mmHg (absolute pressure), a tower head temperature of 117 ° C, and a tower bottom temperature of 185 ° C.

10.96 parts of top-level fractions were obtained from the extraction distillation column, which was 5.42% of low-boiling hydrocarbons such as cumene and α-methylstyrene, 2.7% of high-boiling hydrocarbons such as benzofuran and phenyl hexene, and hydroxyacetone and mesityl oxide. And ketones such as 4.56% and phenol 87.32% (equivalent to 9.57 parts). The bottom fraction of the extractive distillation column is 365 parts of a mixture of phenol and diethylene glycol. The mixture was transferred to a fractional distillation column 15 through a conduit 14, and distilled under a tower pressure of 100 mmHg (absolute pressure) and a column temperature of 122 ° C.

As a result of the distillation operation in the fractionating column, the high-boiling diethylene glycol was discharged to 265 parts (containing about 23 parts of phenol) through the conduit 13 and recycled to the extraction distillation column 12 as an extractive distillation solvent. . Low-boiling phenol was recovered as product via conduit 16. The phenol production amount was 100 parts (recovery rate 97%), and the sulfonated coloring value defined below was 95%.

The sulfonated coloring value was measured as follows.

20 ml of phenol samples were heated for 10 minutes in a 45 ° C. hot bath and immediately mixed with 20 ml of concentrated sulfuric acid. The mixture was left at room temperature for 1 minute and in water for 5 minutes. 20 ml of the sample was transferred to a cell and the light transmittance was measured at 532 mμ using a photochromic colorimeter and expressed in%. The higher the sulfonated coloring value was, the better the purity of the Ksujun phenol was.

Since the low boiling fraction obtained in the extraction distillation column contained 1.64 parts of phenol, distillation was carried out at a ratio of 8.73 parts by weight (9.57 / 109.57 × 100) to 100 parts by weight of phenol contained in the crude phenol. This fraction was transferred to the steam distillation column 18 through the conduit 7, and steam distillation was carried out under a tower pressure of 300 mmHg (absolute pressure), a column temperature of 76 ° C and a tower bottom temperature of 82 ° C. In the steam distillation operation, 2.10 parts of water were added through the conduit 19, and 14.7 parts of the water layer were introduced from the tower top effluent-separation tank 20 through the conduit 21. The oil layer oil (1.32 parts) contained about 17% of phenol in addition to impurities as the main component, and was discharged from the separation tank through the conduit 22. On the other hand, the bottom fraction of the steam distillation column was composed of 9.35 parts of spent phenol and 2.1 parts of water and 0.29 parts of impurities, and the phenol-containing fraction was recycled to the neutralization tank (3) through the conduit (23).

When the method was operated continuously for one year, the purity of the phenol could be maintained without decreasing the recovery rate of phenol, and no alteration of diethylene glycol was observed.

Claims (1)

Contact decomposition of aralkylhydroperoxide with acid to produce phenolic compounds, to recover crude phenolic compounds by removing by-products or impurities with lower or higher boiling point than acid and produced phenolic compounds, and supplying the recovered crude phenolic compounds to an extractive distillation column After extractive distillation in the presence of a polyalkylene glycool or ether thereof having a higher boiling point, the bottom oil is fed to the extractive distillation column in the method for producing a phenolic compound by separating the phenol compound and polyalkylene glycool or ether thereof Extraction and distillation of the phenolic compounds contained in the crude phenolic compound in an amount of about 0.3 to 30% by weight, even if the effluent flows out from the tower, and steam distillation of the phenolic compound-containing oil flowing out from the extraction tower, After the acid catalytic cracking step described above or the bottom oil containing the phenolic compound, Method of preparing the improved phenolic compound characterized by the Sikkim recirculated to any previous step of the extractive distillation step

Images