JP3042366B2 - Method for producing metadiisopropylbenzene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing metadiisopropylbenzene. More specifically,
The present invention relates to a method for continuously producing metadiisopropylbenzene by an alkylation reaction and a transalkylation reaction, using benzene and propylene as raw materials, using a liquid aluminum chloride complex catalyst. Meta-isopropylbenzene, which can be used optimally as a raw material for producing resorcinol through an air oxidation reaction and a decomposition reaction by controlling the amount of ortho-diisopropylbenzene, which is an impurity, to a low level. The present invention relates to a method for producing metadiisopropylbenzene which can be obtained.

[0002]

2. Description of the Related Art A method for producing metadiisopropylbenzene by an alkylation reaction and a transalkylation reaction using benzene and propylene as raw materials using a liquid aluminum chloride complex catalyst is known (for example, Japanese Patent Publication No. Sho 63-54421). Gazette.). Meanwhile, as one of the uses of metadiisopropylbenzene, there is a use as a raw material for producing resorcinol through an air oxidation reaction and a decomposition reaction. That is, metadiisopropylbenzene is converted to metadiisopropylbenzene dihydroperoxide by air oxidation, and resorcinol is further decomposed by acid decomposition of metadiisopropylbenzene dihydroperoxide. Here, if orthodiisopropylbenzene is present as an impurity in metadiisopropylbenzene subjected to air oxidation, the rate of the air oxidation reaction is significantly reduced due to the accumulation of orthodiisopropylbenzene in the oxidized oil system through the recycling process. This causes a problem. This orthodiisopropylbenzene has a boiling point close to that of metadiisopropylbenzene, and it is difficult to separate them from each other by distillation. In the production of metadiisopropylbenzene, it is important to sufficiently promote the reaction to the target product, metadiisopropylbenzene, and to control the amount of by-produced ortho-diisopropylbenzene to a low level. When I saw the technology, I was not always satisfied.

[0003]

In such a situation,
The problem to be solved by the present invention is a method for continuously producing metadiisopropylbenzene by an alkylation reaction and a transalkylation reaction using benzene and propylene as raw materials using a liquid aluminum chloride complex catalyst. The reaction to meta-diisopropylbenzene, which is a product, proceeds sufficiently and the amount of by-produced ortho-diisopropylbenzene, which is an impurity, is controlled to a low level. It is an object of the present invention to provide a method for producing metadiisopropylbenzene which can obtain metadiisopropylbenzene which can be obtained.

[0004]

That is, the present invention provides a method for continuously producing metadiisopropylbenzene by an alkylation reaction and a transalkylation reaction using benzene and propylene as raw materials using a liquid aluminum chloride complex catalyst. Wherein the transalkylation reaction is carried out using two or more reactors arranged in series.

The details will be described below.

[0006] The liquid aluminum chloride complex catalyst (hereinafter referred to as "complex catalyst") used as a catalyst in the present invention is a homogeneous solution complex catalyst comprising aluminum chloride, hydrogen chloride and aromatic hydrocarbon. here,
As the aromatic hydrocarbon, one or a mixture of two or more of benzene, cumene, paradiisopropylbenzene and metadiisopropylbenzene is usually used. A homogeneous solution may be obtained by stirring and mixing 0.5 to 1.0 mol of hydrogen chloride and 2 to 10 mol of aromatic hydrocarbon per 1 mol of aluminum chloride. In this case, the preparation temperature is 2
0-70 ° C is preferred. If the preparation temperature is too high, the catalytic activity will be reduced, and if it is too low, it will take a long time to obtain a homogeneous solution. The preparation time is not particularly limited, but is generally about 10 minutes to 10 hours.

In the alkylation reaction of the present invention, benzene and propylene as raw materials may be brought into contact in the presence of a complex catalyst. Specifically, propylene may be blown into the benzene solution containing the complex catalyst in the reactor.
The raw materials for the alkylation reaction include fresh benzene and propylene newly supplied from outside the reaction system, and benzene and cumene separated and recovered from metadiisopropylbenzene in a separation step after the transalkylation reaction described below. , Paradiisopropylbenzene, triisopropylbenzene, etc. may be recycled and supplied. The molar ratio of fresh benzene and propylene (benzene / propylene) newly supplied from outside the reaction system is usually about 1/2.

[0008] The amount of the complex catalyst used in the alkylation reaction is usually 0.1% based on the concentration of aluminum chloride in the reaction solution.
It is from 0.05 to 1.0% by weight, preferably from 0.1 to 0.5% by weight, more preferably from 0.15 to 0.4% by weight. If the catalyst concentration is low, the reaction is slow, while if the concentration is too high, side reactions increase, and the amount of aluminum chloride used increases, which is uneconomical. In order to promote the alkylation reaction, 0.01 mol per mol of aluminum chloride is used as a co-catalyst.
~ O. Two moles of hydrogen chloride may be added. The reaction temperature is usually from 50 to 150 ° C, preferably from 50 to 120 ° C, more preferably from 60 to 100 ° C. At low temperatures, excessive cooling energy for heat removal of the reaction is required, and at high temperatures, side reaction products such as ethylisopropylbenzene increase. The reaction pressure is generally from atmospheric pressure to about 20 kg / cm ² G
It is. The reaction time depends on the reaction conditions, but generally ranges from 1 to
100 minutes.

The alkylation reaction is a very fast reaction,
One reactor is sufficient and there is no economic benefit to having more than two reactors. The reactor is preferably provided with an external circulation line with a heat exchanger for heat removal.

[0010] In the reaction solution obtained by the alkylation reaction, cumene, orthodiisopropylbenzene, paradiisopropylbenzene, triisopropylbenzene and the like are present in addition to metadiisopropylbenzene as a target substance and benzene as a raw material. By the way, when transalkylation reaction is sufficiently performed, it is known that these compounds reach a certain equilibrium concentration. The concentration of each compound in the equilibrium state is mainly determined by the ratio of the number of moles of isopropyl groups to the number of moles of phenyl groups (hereinafter referred to as “P”).
/ B ". ) And temperature, for example 80
The equilibrium concentration of metadiisopropylbenzene when P / B = 1.55 at ° C is about 35% by weight. However, the reaction solution after the alkylation reaction is generally in a state of not reaching an equilibrium state, and compared with the equilibrium state, the concentration of the target metadiisopropylbenzene is lower, and benzene, paradiisopropylbenzene, and triisopropylbenzene are lower. High concentration of species. Therefore, the composition of the reaction solution is brought close to the equilibrium state (that is, the “equilibrium achievement rate is increased”), the concentration of metadiisopropylbenzene, which is the target substance, is increased, and the concentration of orthodiisopropylbenzene, which is the undesirable impurity, is reduced. It is necessary. In order to achieve this object, the next step, a transalkylation reaction, is performed.

The transalkylation reaction of the present invention is carried out using two or more reaction tanks arranged in series, preferably three or more reaction tanks. As a result, a sufficiently high equilibrium attainment rate can be realized.

As the starting material for the transalkylation reaction, an alkylation reaction solution containing the above-described complex catalyst is used, but the recycle component described in the description of the alkylation reaction may be added. Further, a new complex catalyst or a hydrogen chloride promoter may be added. The reaction temperature is usually 50 to 150 ° C.,
-120 ° C is preferred, and 60-100 ° C is more preferred. At low temperatures, the reaction is slow, and at high temperatures, side reaction products such as ethylisopropylbenzene increase. The reaction pressure is generally from atmospheric pressure to about 10 Kg / cm ² G. Reaction time (total reaction time of all reactors for transalkylation reaction)
Is generally 50 to 300 minutes, depending on the reaction conditions.
In addition, it is preferable that the distribution of the reaction time in each reaction tank is generally substantially equal to each reaction tank. The reaction solution of the transalkylation reaction thus obtained has a sufficiently high equilibrium attainment ratio, that is, the concentration of metadiisopropylbenzene as the target substance is sufficiently high, and the concentration of orthodiisopropylbenzene, which is an undesirable impurity, is high. Is kept low.

[0013] An ordinary method is used to obtain metadiisopropylbenzene as an objective substance from the obtained reaction solution of the transalkylation reaction. For example, after separating the complex catalyst from the reaction mixture by a liquid separation operation or after washing the reaction mixture with water or caustic and removing the complex catalyst, the obtained oil layer is distilled, and benzene, cumene, p-diisopropylbenzene and The target metadiisopropylbenzene fraction can be separated from a plurality of fractions composed of triisopropylbenzenes and the like. At this time, each fraction other than the target substance can be recycled to the alkylation reaction or transalkylation reaction. By such a method, the purity of metadiisopropylbenzene is 9
It is possible to easily obtain a target product having an orthodiisopropylbenzene content of 9% or more and 0.5% or less.

[0014]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention (see Table 1).

Example 1 (1) Preparation of complex catalyst In a 2 l flask, 80% by weight of cumene and 12 parts of benzene were added.
654 g of a mixed solvent containing 1% by weight of hydrogen chloride gas was added thereto, and hydrogen chloride gas was blown into the solution at 15.8 g / Hr with stirring.
At 0 ° C., 300 g of 8-20 mesh solid aluminum chloride was added over 155 minutes. Furthermore, at 40 ° C., 6
The mixture was stirred and mixed for 0 minutes to completely dissolve the aluminum chloride to obtain a liquid aluminum chloride complex. The amount of hydrogen chloride gas dissolved in the above complex determined from the difference between the amount of hydrogen chloride gas fed and the amount of purge was about 0.7 in molar ratio to aluminum chloride.

(2) Alkylation reaction and transalkylation reaction An overflow-type continuous reaction equipment comprising one alkylation reaction tank and three transalkylation reaction tanks arranged in series was used. The above-mentioned complex catalyst, hydrogen chloride co-catalyst, propylene and benzene as well as a recycled cumene fraction and a recycled p-diisopropylbenzene fraction were continuously fed to the alkylation reactor. An aluminum chloride concentration of 0.25% by weight in the reaction solution, a hydrogen chloride / aluminum chloride molar ratio of 0.1, a P / B ratio (isopropyl group with propylene / phenyl group with benzene) of 1.55,
Alkylation reaction tank temperature 80 ° C, transalkylation reaction tank temperature 85 ° C, reaction time in alkylation reaction tank (same as residence time (reactant liquid holding amount in reaction tank / liquid flow rate)) 20
A continuous reaction was performed for a total reaction time of 60 minutes (each tank 20 minutes × 3) in the transalkylation reaction tank for a total reaction time of 80 minutes. As a result, the meta-diisopropylbenzene (MDC) concentration in the reaction solution in the steady state was 34.3% by weight, and the ortho-diisopropylbenzene (ODC) concentration was 0.3% by weight.
13% by weight, the equilibrium attainment rate was 98.0%, and the ODC generation rate was 0.38%. Note that the equilibrium arrival rate and OD
The C generation rate was determined by the following equation. The reaction solution thus obtained was post-treated according to a conventional method to give a purity of 99% or more and an ODC content of 0.1%.
5% or less of MDC was obtained.

Equilibrium achievement rate (%) = 100 × (M of the reaction solution)
(DC weight concentration) / (MDC equilibrium weight concentration) ODC generation rate (%) = 100 × (reaction liquid ODC weight concentration) / (reaction liquid MDC weight concentration)

Example 2 The same procedure as in Example 1 was carried out except that the transalkylation reaction was carried out in two tanks (the liquid holding amount in each tank was 1.5 times that of Example 1). As a result, the MDC concentration in the reaction solution in the steady state was 33.6% by weight, and the ODC concentration was 0.1%.
5% by weight, equilibrium attainment rate 96.0%, ODC generation rate 0.4
5%. The resulting reaction solution was post-treated according to a conventional method to obtain MDC having a purity of 99% or more and an ODC content of 0.5% or less.

Comparative Example 1 Example 1 was conducted except that the transalkylation reaction was carried out in one tank (the amount of liquid held in the tank was set to three times that in Example 1).
The same was done. As a result, in the steady state, the MDC concentration in the reaction solution was 31.0 wt%, and the ODC concentration was 0.19 wt%.
%, Equilibrium attainment rate of 88.6%, and ODC generation rate of 0.61%. The resulting reaction solution was post-treated according to a conventional method, but MDC having a purity of 98.5% and an ODC content of 0.60% was obtained, and MDC having a high purity and a low ODC content as in the example could not be obtained. .

[0020]

[Table 1]------------------------------------------------------------------------------------------------------------------------------------------------------------- (Group) 3 2 1 Reaction result MDC concentration wt% 34.3 33.6 31.0 ODC concentration wt% 0.13 0.15 0.19 Equilibrium attainment% 98.0 96.0 88.6 ODC generation% 0.38 0.45 0.61 −−−−−−−−−−−−−−− −−−−−−−−−−−−−−−−−−−−

[0021]

As described above, according to the present invention, a method for continuously producing metadiisopropylbenzene by an alkylation reaction and a transalkylation reaction using benzene and propylene as raw materials using a liquid aluminum chloride complex catalyst. Metadiisopropyl, which can control the amount of by-produced ortho-diisopropylbenzene, which is an impurity, to a low level, thereby obtaining metadiisopropylbenzene that can be optimally used as a raw material for producing resorcinol through an air oxidation reaction and a decomposition reaction. A method for producing benzene can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroaki Abegawa 5-1, Anesaki Beach, Ichihara-shi, Chiba Sumitomo Chemical Industries Co., Ltd. (72) Inventor Yuki Hamai 5-1, Anesaki Beach, Ichihara-shi, Chiba Sumitomo Chemical Industrial Co., Ltd. In-company (56) References JP-A-58-172327 (JP, A) JP-A-57-40423 (JP, A) JP-A-57-40418 (JP, A) (58) Fields investigated (Int. . ^7, DB name) C07C 2 / 68,5 / 27,6 / 12 C07C 15 / 02,15 / 085

Claims (2)

(57) [Claims] 1. A method for continuously producing metadiisopropylbenzene by an alkylation reaction and a transalkylation reaction using benzene and propylene as raw materials by using a liquid aluminum chloride complex catalyst, wherein two or more tanks are arranged in series. A method for producing metadiisopropylbenzene, wherein a transalkylation reaction is carried out using the reactor of (1). 2. The production method according to claim 1, wherein the transalkylation reaction is carried out using three or more reactors arranged in series.