JPH09143111A - Hydroperoxide decomposition method - Google Patents

Abstract

(57) Abstract: A method for decomposing hydroperoxide, which comprises subjecting diisopropylbenzene dihydroperoxide to a decomposition reaction in the liquid phase in the presence of an acid catalyst to convert it into dihydroxybenzene and acetone. Provided is a method for decomposing hydroperoxide, which suppresses the by-product of the above to a low level and is advantageous in terms of thermo-economics. A method for decomposing hydroperoxide in which diisopropylbenzene dihydroperoxide is subjected to a decomposition reaction in the liquid phase in the presence of an acid catalyst to convert into dihydroxybenzene and acetone, which comprises the following (A) and ( A method for decomposing hydroperoxide having the characteristics of B). (A): A decomposition reactor equipped with a rectification tower is used, and a decomposition raw material liquid and an acid catalyst are supplied to the decomposition reactor to allow the decomposition reaction to proceed while the decomposition reaction is performed from the upper part of the rectification tower. Removal of at least a part of generated acetone outside the reaction system (B): the concentration of diisopropylbenzene dihydroperoxide in the decomposition raw material liquid supplied to the decomposition reactor is 10
~ 25% by weight

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for decomposing hydroperoxide. More specifically,
The present invention is a method for decomposing hydroperoxide in which diisopropylbenzene dihydroperoxide is subjected to a decomposition reaction in the liquid phase in the presence of an acid catalyst to convert it into dihydroxybenzene and acetone. The present invention relates to a method for decomposing hydroperoxide, which is suppressed to a level and is also advantageous in terms of heat economy.

[0002]

BACKGROUND ART A method for obtaining dihydroxybenzene and acetone by air-oxidizing diisopropylbenzene to diisopropylbenzene dihydroperoxide, and further decomposing the diisopropylbenzene dihydroperoxide in the presence of an acid catalyst is known. is there.
Here, as dihydroxybenzene, resorcin or hydroquinone can be mentioned. By the way, as a method for decomposing the above diisopropylbenzene dihydroperoxide, diisopropylbenzene dihydroperoxide is decomposed in the presence of an acid catalyst to convert into dihydroxybenzene and acetone, and then the obtained dihydroxybenzene is obtained. It has been a conventional method to separate and collect dihydroxybenzene and acetone by subjecting a mixed solution of acetone and acetone to rectification (see, for example, JP-A-53-95929). However, this method has a problem that a considerable amount of tar is by-produced during the decomposition reaction. The generation of the tar leads to loss of dihydroxybenzene and acetone, which are the target products, and the generated tar adheres to the reactor and the piping part, which makes smooth operation difficult, and is an additional component for separating the tar. However, this is very inconvenient, especially from the viewpoint of industrial implementation.

[0003]

Under such circumstances, the problem to be solved by the present invention is to subject diisopropylbenzene dihydroperoxide to decomposition reaction in the liquid phase in the presence of an acid catalyst to give dihydroxybenzene and A method for decomposing hydroperoxide to convert to acetone,
It is to provide a method for decomposing hydroperoxide, which suppresses the by-product of tar to a low level and is advantageous in terms of thermo-economics.

[0004]

[Means for Solving the Problems] That is, the present invention provides a decomposition reaction of diisopropylbenzene dihydroperoxide in the liquid phase in the presence of an acid catalyst to convert it into dihydroxybenzene and acetone. The present invention relates to a method for decomposing hydroperoxide having the following characteristics (A) and (B). (A): A decomposition reactor equipped with a rectification tower is used, and a decomposition raw material liquid and an acid catalyst are supplied to the decomposition reactor to allow the decomposition reaction to proceed while the decomposition reaction is performed from the upper part of the rectification tower. Removal of at least a part of generated acetone outside the reaction system (B): The concentration of diisopropylbenzene dihydroperoxide in the decomposition raw material liquid supplied to the decomposition reactor is 10
~ 25% by weight

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is a hydroperoxide decomposition method in which diisopropylbenzene dihydroperoxide is subjected to a decomposition reaction in the liquid phase in the presence of an acid catalyst to convert it into dihydroxybenzene and acetone.

Examples of diisopropylbenzene dihydroperoxide include metadiisopropylbenzene dihydroperoxide and paradiisopropylbenzene dihydroperoxide. These compounds are usually obtained by air oxidation of the corresponding diisopropylbenzene. At this time, diisopropylbenzene dihydroperoxide is usually obtained as an organic solvent solution by first extracting an aqueous layer with an alkali from the diisopropylbenzene oxidation reaction solution and then re-extracting the alkaline aqueous layer with an organic solvent. To be Since a compound having a 2-hydroxy-2-propyl group, which is mixed in a small amount in diisopropylbenzene dihydroperoxide, may interfere with the decomposition reaction, it should be removed in advance by rectification or extraction. It is preferable.

The decomposition reaction is carried out in the liquid phase. As the solvent at the time of reaction, ketones such as acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl isopropyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone; ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran, dioxane; Alcohols such as methanol, ethanol and propanol; benzenes such as benzene, toluene and xylene; and mixtures thereof are commonly used. Among these, it is preferable from the industrial viewpoint that the organic solvent used for the re-extraction is used as the solvent for the main decomposition reaction. Also,
A solvent that is stable under the decomposition reaction conditions using an acid catalyst is preferred. From these viewpoints, ketones are preferable, and methyl isobutyl ketone is particularly preferable.

As the acid catalyst, sulfuric anhydride; benzenesulfonic acids such as p-toluenesulfonic acid; methanesulfonic acid, trichloromethanesulfonic acid, trifluoromethanesulfonic acid, perchloric acid, phosphoric acid, hydrochloric acid, hydrogen fluoride,
Examples thereof include trichloroacetic acid, trifluoroacetic acid, aluminum chloride, boron trifluoride, boron trifluoride complex, cation exchange resin, and the like, and a compound having a property as an antioxidant containing a sulfur atom or the like can also be used. . Of these, sulfuric anhydride is preferred from the viewpoint of decomposition yield. The amount of the acid catalyst used is 0.005 to 5 of the decomposition raw material liquid.
A range of weight% is preferred. If the amount used is too small, the desired decomposition reaction may not proceed sufficiently, while if the amount used is too large, the reaction may proceed and tar generation may increase. When sulfuric acid anhydride is used as the acid catalyst, the amount used is preferably in the range of 50 to 150 ppm by weight of the decomposition raw material liquid. Sulfuric anhydride is usually supplied to the decomposition reactor in the form of a solution dissolved in acetone. The concentration of the acid catalyst in the acetone solution is usually 0.1 to 10% by weight.

The preferred temperature and pressure conditions for the decomposition reaction are a temperature of 60 to 100 ° C. and a pressure of 200 to 700 Tor.
You can raise r. If the decomposition temperature is too low, the desired decomposition reaction may not proceed sufficiently, while if the decomposition temperature is too high, tar formation may increase. If the decomposition pressure is too low, the reaction temperature may not be kept high, while if the decomposition pressure is too high, the temperature required for distilling acetone may be high, and tar formation may increase. The preferable decomposition reaction time (residence time in the decomposition reaction zone) is 1 to 15 minutes. If the decomposition reaction time is too short, the desired decomposition reaction may not proceed sufficiently, while if the decomposition reaction time is too long, the reaction may proceed and tar formation may increase. Since the decomposition reaction is accompanied by a large amount of heat generation, in order to maintain the above reaction temperature, the reactor is provided with a cooler and the reaction is carried out while cooling.

The present invention uses a cracking reactor equipped with a rectification column at the top, supplies a cracking raw material liquid and an acid catalyst to the cracking reactor, allows the cracking reaction to proceed, and from the upper part of the rectification column. It is carried out by removing at least a part of acetone generated by the decomposition reaction outside the reaction system.

A cracking reactor having a rectification tower at the upper part means a reactor having a structure having a reaction tank for carrying out the cracking reaction and a rectification tower installed directly above the reaction tank. means. The reaction tank is provided with a cooling means for maintaining the reaction temperature. As the rectification column, a tray type or a packed column type is used. As is clear from the structure of the above-mentioned reactor, among the reaction products generated in the reaction tank, acetone having a low boiling point and a part of the reaction solvent rise in the rectification column and are distilled from the top of the column. To be done. Then, the distilled component is cooled and condensed by a cooler, a part of the condensed liquid component is returned to the rectification column as reflux, and the rest is removed to the outside of the reaction system by being sent to a post process. To be done. Here, the amount of acetone generated by the decomposition reaction removed to the outside of the system is preferably 30% or more of the total amount of acetone generated by the decomposition reaction. This makes it possible to maintain the tar by-product accompanying the decomposition reaction at a lower level.

In the present invention, the concentration of diisopropylbenzenedihydroperoxide in the decomposition raw material liquid supplied to the decomposition reactor must be 10 to 25% by weight, and more preferably 15 to 20% by weight. It is necessary to be. If the concentration is too low, the productivity of the target product per reactor volume will decrease, and the energy required for solvent separation in the subsequent step will be large, which will be industrially disadvantageous, while if the concentration is too high, tar generation will increase. To do. Here, the decomposition raw material liquid is a solution containing diisopropylbenzene dihydroperoxide in a solvent, and as the solvent, those mentioned as the solvent in the above reaction are used. That is, the solvent that constitutes the decomposition raw material liquid becomes the solvent during the decomposition reaction. Since the water content in the decomposition raw material liquid may lower the activity of the acid catalyst, it is preferable to subject the decomposition raw material liquid to distillation in advance so that the water content in the decomposition raw material liquid is 1% by weight or less.

In the present invention, diisopropylbenzene dihydroperoxide, solvent and acid catalyst are supplied to the decomposition reactor as main components. Then, acetone and a part of the solvent are recovered from the top of the rectification column, and a mixed liquid composed of dihydroxybenzene, tar, the solvent and a part of the acetone is recovered.

The present invention is usually carried out as a continuous process, but it is preferable to maintain the concentration of diisopropylbenzene dihydroperoxide in the entire decomposition reaction solution in a steady state at 0.5% by weight or less. This allows the tar by-product to be maintained at a much lower level and avoids safety issues associated with hydroperoxide explosion.

According to the present invention, the by-product of tar during the decomposition reaction can be suppressed to a low level. As a reason for this, the present inventors presume as follows as a result of the examination. That is, dihydroxybenzene and acetone react with each other in a heating environment to generate tar, but in the present invention, they are produced by defining the concentration of diisopropylbenzene dihydroperoxide in the decomposition raw material liquid at a relatively low level. The concentration of dihydroxybenzene and acetone was kept low to reduce the chance of tar reaction, and the generated acetone was immediately removed to the outside of the system by rectification to reduce the chance of tar reaction. Therefore, it is possible to prevent the by-product of tar.

Further, the present invention directly utilizes the heat generated in the decomposition reaction as a heat source for rectification, which is an advantageous method from the viewpoint of thermal economy.

[0017]

【Example】

Example 1 Metadiisopropylbenzene dihydroperoxide (m-DHPO) 1 was added to a special reaction flask equipped with a 100 ml bulb as a reaction tank and a rectification column above it.
Methyl isobutyl ketone containing 9.9% by weight (MIB
K) 80 ml of the solution (reaction material liquid) was charged. As the reaction raw material liquid, a MIBK solution of m-DHPO obtained by air-oxidizing diisopropylbenzene was used. While stirring the reaction raw material liquid, a separate reaction raw material liquid and an acetone solution of sulfuric anhydride (sulfuric acid concentration 0.4% by weight) were continuously fed to the flask at 1407 g / hr and 36.5 g / hr, respectively. . At this time, the amount of anhydrous sulfuric acid with respect to the reaction raw material liquid was 101 ppm by weight. The temperature of the reaction liquid was kept at 90 ° C., and the decomposition reaction was performed at a pressure of 520 Torr. The residence time was 3 minutes. The generated light boiling point components such as acetone rise in the rectification column, and from the top of the column, 116.8 g /
The liquid in the reaction tank such as resorcin was withdrawn at a rate of 1326.4 g / hr from the overflow portion of the flask as a distillate. The distillation rate of acetone (acetone removed outside the system / total acetone distilled from the top of the rectification column × 100) was 45%. As a result of collecting and analyzing the bottoms and distillates only for 40 minutes when the system was stable, the substance recovery rate of the entire system was 99.98%, and the decomposition yield [total recovered resorcinol (mol) / M-D supplied
HPO (mol) × 100] was 92.6%, and the tar component yield [collected tar (g) / supplied m-DHP].
O (g) × 100] was 5.18%.

The m-DHPO concentration used to calculate the decomposition yield and the tar component yield was the sodium thiosulfate titration method and the liquid chromatography method, the resorcin concentration was the gas chromatography method, and the tar component concentration was the gel permeation method. Analysis was carried out by the ion chromatography (GPC) method, and the obtained value was used.

Examples 2 to 3 and Comparative Examples 1 to 4 The same procedure as in Examples was carried out except that the conditions shown in Table 1 were used.
The results are shown in Table 1. The following can be seen from the results. All the examples satisfying the conditions of the present invention show satisfactory results. On the other hand, Comparative Example 1, Comparative Example 3 and Comparative Example 4 using a decomposition raw material liquid having an excessively high metadiisopropylbenzene dihydroperoxide concentration, and a decomposition raw material liquid having an excessively high metadiisopropylbenzene dihydroperoxide concentration, and Comparative Example 2 in which acetone was not removed from the upper part of the distillation column showed that the yield of decomposition was low and the yield of tar was high, so that a large amount of tar was produced as a by-product.

[0020]

[Table 1]

[0021]

[Table 2] −−−−−−−−−−−−−−−−−−−−−−−−−−−−− Comparison Example 1 2 3 4 Conditions Reaction temperature ℃ 90 75 105 100 Reaction pressure Torr 510 306 760 760 Residence time min 2.9 9.6 4.4 3.0 Acid catalyst amount wt ppm * 1 102 57 35 103 m-DHPO concentration wt% * 2 27.1 28.3 27.8 27.5 ACT Distillation ratio% * 3 47 0 49 39 Results Decomposition yield % * 4 89.8 83.5 81.1 85.7 Tar yield% * 5 6.43 6.58 8.86 8.98 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

* 1 Amount of acid catalyst: ratio to decomposition raw material liquid * 2 m-DHPO concentration: concentration of metadiisopropylbenzene dihydroperoxide in decomposition raw material liquid * 3 ACT distilling ratio: acetone removed outside system / purified Total acetone distilled from the top of the distillation column × 100 * 4 Decomposition yield: total resorcinol (mol) recovered / m-DHPO (mol) supplied × 100 * 5 Tar yield: recovered tar (g) / Supplied m
-DHPO (g) x 100

[0023]

As described above, according to the present invention, a method for decomposing hydroperoxide in which diisopropylbenzene dihydroperoxide is subjected to a decomposition reaction in the liquid phase in the presence of an acid catalyst to convert into dihydroxybenzene and acetone. In addition, it was possible to provide a method for decomposing hydroperoxide, which suppresses the by-product of tar to a low level and is also advantageous in terms of thermo-economics.

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Claims (1)

[Claims] 1. A method for decomposing hydroperoxide, which comprises subjecting diisopropylbenzene dihydroperoxide to a decomposition reaction in the liquid phase in the presence of an acid catalyst to convert it into dihydroxybenzene and acetone. A method for decomposing hydroperoxide having the characteristics of (B). (A): A decomposition reactor equipped with a rectification tower is used, and a decomposition raw material liquid and an acid catalyst are supplied to the decomposition reactor to allow the decomposition reaction to proceed while the decomposition reaction is performed from the upper part of the rectification tower. Removal of at least a part of generated acetone outside the reaction system (B): The concentration of diisopropylbenzene dihydroperoxide in the decomposition raw material liquid supplied to the decomposition reactor is 10
~ 25% by weight