JP3761342B2 - Method for regenerating catalyst for bisphenol A production - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an organic polymer siloxane having a sulfonic acid group-containing hydrocarbon group and a mercapto group-containing hydrocarbon group, which is a catalyst for producing 2,2′-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A). The present invention relates to a method for regenerating a catalyst whose activity has deteriorated when used in a reaction.
[0002]
[Prior art]
Bisphenol A is usually an excess of 8 to 15 times in a molar ratio with acetone in a solid catalyst such as a mercapto-modified cation exchange resin in which a cation exchange resin or a mercaptoalkylamine is partially neutralized and a mercapto group is immobilized. In the form of a so-called fixed bed flow reaction in which phenol is passed through. Moreover, as a solid catalyst other than an ion exchange resin catalyst, JP-A-8-208545 and DE195536363 describe an organic polymer siloxane catalyst having a sulfonic acid group-containing hydrocarbon group and a mercapto group-containing hydrocarbon group. It is known that the organic polymer siloxane catalyst is a solid catalyst having high heat resistance and very high catalytic activity and selectivity as compared with the ion exchange resin catalyst. In the production method using a heterogeneous catalyst using a solid catalyst, the catalytic activity gradually deteriorates during its use, and after a certain period of use, it must be replaced with a new catalyst. Such a catalyst exchange requires a lot of labor and must be stopped for a long time, which is not economical. Accordingly, there has been a strong demand for the development of a method for industrially regenerating an activated catalyst.
[0003]
As such a catalyst regeneration method, Japanese Patent Application Laid-Open No. 10-174880 describes that the catalytic activity is completely regenerated by washing the ion-exchange resin catalyst whose activity has deteriorated with a water / phenol mixture. . The authors consider that the cause of the activity degradation is a heavy product that is a by-product, and that the catalytic activity has been recovered by removing the heavy product with a water / phenol mixture. At this time, it is also described that when water or phenol is used alone, the catalytic activity is not recovered, and the catalytic activity cannot be completely recovered unless it is a water / phenol mixture.
[0004]
However, in an acid catalyst, water is a poisonous substance that adds to the acid sites to reduce the acid strength and significantly lowers the catalytic activity. In order to resume production of bisphenol A after washing with a water / phenol mixture, Must remove the large amount of water added to the acid sites. In particular, in the case of the aromatic sulfonic acid usually used in this reaction, since the acid strength is very strong, water is strongly added, and much labor is required to remove it. In addition, it is well known that aromatic sulfonic acid is hydrolyzed by water and sulfonic acid is eliminated. Accordingly, water is an inconvenient substance for use in the regeneration treatment, and the method of washing with a water / phenol mixture is not an industrial catalyst regeneration method. Industrially, it is most advantageous to use only phenol, which is one of the raw materials, but ion-exchange resins have low heat resistance, and there is almost no effect of washing with phenol below the heat-resistant temperature such as 80 to 120 ° C. It was difficult to completely recover the catalytic activity.
[0005]
[Problems to be solved by the invention]
The present invention relates to an organic polymer whose activity has deteriorated in producing bisphenol A by dehydration condensation of acetone and phenol in the presence of an organic polymer siloxane catalyst having both a sulfonic acid group-containing hydrocarbon group and a mercapto group-containing hydrocarbon group. Provided is a method for industrially regenerating a siloxane catalyst without using water.
[0006]
[Means for Solving the Problems]
In the production of bisphenol A by dehydration condensation of acetone and phenol in the presence of an organic polymer siloxane having both a sulfonic acid group-containing hydrocarbon group and a mercapto group-containing hydrocarbon group, the present inventors As a result of intensive studies on a method for industrially regenerating the molecular siloxane catalyst, attention was paid to the high heat resistance of the organic polymer siloxane catalyst. The present inventors have found a catalyst regeneration method characterized by washing with one phenol, and have completed the present invention.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The organic polymer siloxane catalyst having a sulfonic acid group-containing hydrocarbon group and a mercapto group-containing hydrocarbon group to be used in the present invention is described in JP-A-8-208545 and DE195536363 in a silica matrix comprising a siloxane bond. An organic polymer siloxane having a structure in which a hydrocarbon group having a sulfonic acid group and a hydrocarbon group having a mercapto group are directly bonded to a silicon atom in a silica matrix by a carbon-silicon bond.
Such an organic polymer siloxane catalyst can be prepared, for example, by the following method. However, the organic polymer siloxane catalyst having a sulfonic acid group-containing hydrocarbon group and a mercapto group-containing hydrocarbon group used in the present invention is not limited to these preparation methods.
[0008]
Examples of easy preparation methods include:
(1) A preparation method in which an alkoxysilane having a sulfonic acid group-containing hydrocarbon group, an alkoxysilane having a mercapto group-containing hydrocarbon group, and a tetraalkoxysilane are mixed at an arbitrary ratio, hydrolyzed, and co-condensed.
(2) Hydrolysis of an alkoxysilane having a water-soluble sulfonic acid group-containing hydrocarbon group, an alkoxysilane having a mercapto group-containing hydrocarbon group, and tetraalkoxysilane as a diluent at an arbitrary ratio, and hydrolysis A preparation method (1) (2) of a so-called alkoxysilane sol-gel method, such as a preparation method for co-condensation by
(3) Preparation method by so-called silylation, in which an alkoxysilane having a mercapto group-containing hydrocarbon group is silylated to a silanol group present in an organic polymer siloxane having a sulfonic acid group-containing hydrocarbon group, and the mercapto group is immobilized ( 3) is known.
In the present invention, an organic polymer siloxane catalyst having a sulfonic acid group-containing hydrocarbon group and a mercapto group-containing hydrocarbon group obtained by these preparation methods is used in a bisphenol A production reaction.
[0009]
In order to carry out the present invention, a fixed bed flow reactor filled with an organic polymer siloxane catalyst which is a reactor for producing bisphenol A is used as it is.
Only phenol, which is one of the raw materials, is passed through the activated organic polymer siloxane catalyst and the temperature is raised. The residence time in this case is not particularly limited, but is usually 0.1 second to 30 hours, preferably 0.5 second to 15 hours. The temperature is 120 ° C to 250 ° C, preferably 140 ° C to 250 ° C, more preferably 150 ° C to 230 ° C. If the treatment temperature is too low, an extremely long treatment time is required to restore the catalyst activity to the initial reaction start level, which is not economical.
On the other hand, if the treatment temperature is too high, the decomposition of the mercapto group occurs and the catalyst may be deactivated. The total amount of phenol used in the regeneration treatment is 1 to 20 times, preferably 2 to 10 times the catalyst weight. After the regeneration treatment, the reactor can be used again for producing bisphenol A as it is.
[0010]
【Example】
Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to these examples.
(A) Synthesis of sulfonic acid group-containing alkoxysilane.
200 ml of methylene chloride was placed in a two-necked 500 ml round bottom flask equipped with a dropping funnel, and 124.02 g (0.585 mol) of phenyltrichlorosilane was added to the flask and ice-cooled. A solution prepared by dissolving 46.80 g (0.585 mol) of anhydrous sulfuric acid in 100 ml of methylene chloride was dropped into this over 30 minutes under a nitrogen stream, and then the ice bath was removed and the mixture was stirred at room temperature for several hours for sulfonation. The dropping funnel was removed, and the mixture was heated to 120 ° C. using an oil bath under a nitrogen stream to distill off methylene chloride and unreacted anhydrous sulfuric acid. After allowing to cool, 161.50 g of ethanol was added dropwise at room temperature over 30 minutes, followed by ethoxylation while removing hydrogen chloride generated by refluxing for several hours while bubbling with nitrogen. The sulfonic acid component in the sol-gel preparation of the organic polymer siloxane catalyst having the following sulfonic acid group-containing hydrocarbon group and mercapto group-containing hydrocarbon group was obtained by using 238.60 g of the obtained phenylsulfonic acid group-containing ethoxysilane ethanol solution. Used as a raw material.
(B) Preparation of an organic polymer siloxane having a sulfonic acid group-containing hydrocarbon group and a mercapto group-containing hydrocarbon group.
[0011]
In a two-necked 500 ml round bottom flask equipped with a stir bar, 26.00 g of the sulfonic acid group-containing ethoxysilane ethanol solution, 35.50 g (170.67 mmol) of tetraethoxysilane, 6.72 g of mercaptopropyltrimethoxysilane ( 34.28 mmol) and 30 ml of ethanol were mixed. 7.53 g (0.418 mol) of water was added dropwise thereto over 30 minutes. This was then heated and stirred at 65 ° C. for 4 hours. After allowing to cool, an aqueous solution in which 28% ammonia water and 75 ml of water were mixed was added dropwise and stirred at room temperature for 4 hours. Further, the mixture was stirred at 65 ° C. for 3 days and aged. This was distilled off under reduced pressure with an evaporator to obtain a white solid. Next, 200 ml of 2N hydrochloric acid was added, and the mixture was stirred at room temperature for 30 minutes to return to the proton type. After separation by filtration, the operation of washing with 500 ml of ion exchange water was repeated 10 times to remove hydrochloric acid. Finally, it was dried at 100 ° C. under reduced pressure for 6 hours. By the above operation, 30.00 g of an organic polymer siloxane having a sulfonic acid group-containing hydrocarbon group and a mercapto group-containing hydrocarbon group was obtained. It was 1.01 meq / g when the solid acid amount of this catalyst was measured.
[0012]
Example 1
A cylindrical reactor (diameter: 16 mm, length: 100 mm) was charged with 10.0 g (20 cc) of the organic polymer siloxane catalyst described above. From the bottom of the reactor, a phenol / acetone mixture having a molar ratio of 12: 1 was passed through the catalyst at a rate of 20.00 g / hr. The reaction temperature was 75 ° C., and the reaction product obtained after 20 hours was analyzed. As a result, the conversion of acetone was 100% and the selectivity for bisphenol A was 95%. Further, the reaction was continued, and the reaction solution obtained after 1000 hours was analyzed. As a result, the conversion of acetone was reduced to 80%, and a decrease in catalytic activity was observed. The reaction was then stopped and phenol was passed through the catalyst from the bottom of the reactor at a rate of 10.00 g / h. The treatment temperature was 150 ° C. and 400 g of total phenol was passed through.
(Phenol residence time: 2 hours)
Next, the temperature of the reactor was lowered to restart the reaction, and a phenol / acetone mixture having a molar ratio of 12: 1 was again passed through the catalyst from the lower side of the reactor at a rate of 20.00 g / hr. The reaction temperature was 75 ° C., and the reaction solution obtained 20 hours after the resumption of the reaction was analyzed. As a result, the conversion of acetone was 100% and the selectivity for bisphenol A was 95%. It was shown that the catalyst activity was completely recovered by the catalyst regeneration method described above.
[0013]
Comparative Example 1
In Example 1, the treatment temperature for catalyst regeneration with phenol was set to 100 ° C. As a result of analyzing the reaction solution obtained 20 hours after the reaction was resumed, the conversion rate of acetone was 85%, and the catalyst activity could not be completely recovered.
[0014]
【The invention's effect】
According to the present invention, only the phenol, which is one of the raw materials, is passed through a reactor filled with a catalyst for producing bisphenol A at 120 to 250 ° C., thereby easily regenerating the organic polymer siloxane catalyst whose activity has deteriorated. be able to. Therefore, a lot of labor as seen in catalyst exchange is not required, and catalyst regeneration can be performed economically.

Claims (1)

When producing bisphenol A by dehydration condensation of acetone and phenol in the presence of an organic polymer siloxane catalyst having both a sulfonic acid group-containing hydrocarbon group and a mercapto group-containing hydrocarbon group, A method for regenerating a catalyst for producing bisphenol A, comprising washing with phenol at 120 ° C to 250 ° C.