JPH04305564A - Production of cumene hydroperoxide - Google Patents

Abstract

PURPOSE:To produce cumene hydroperoxide in high concentration efficiently and stably for a long period of time. CONSTITUTION:In continuous production of cumene hydroperoxide by oxidizing cumene in the presence of oxygen or an oxygen-containing gas, the reaction is carried out by two or more multi-stage reactors connected in series in the absence of an alkali salt and a catalyst, total retention time of the reaction solution and temperature of the reaction solution in a range of <=25wt.% concentration of cumene hydroperoxide in the reaction solution are 0.1-25 hours and 100-120 deg.C, respectively, total retention time of the reaction solution and temperature of the reaction solution in a range of >25wt.% concentration are 0.1-10 hours and 90-115 deg.C, total retention of the reaction solution of cumene hydroperoxide is 3-16 hours and reaction pressure is 2-10kg/cm<2> gauge pressure.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention produces cumene hydroperoxide (hereinafter referred to as CHP) by liquid phase oxidation of cumene.
Relating to a method of manufacturing.

0002

[Prior Art] The reaction of oxidizing cumene to synthesize CHP is an important step in the cumene phenol process.
CHP is also widely used as an oxidizing agent in various reactions.

The oxidation of cumene is carried out in the liquid phase in the presence of oxygen or an oxygen-containing gas, generally under pressure of several atmospheres. The substance produced by the reaction, other than CHP, is dimethylphenyl carbinol (hereinafter referred to as C'nol).
and acetophenone (hereinafter referred to as A'none) account for the majority, but some organic acids such as formic acid and acetic acid are also produced as by-products. C
HP is a substance that easily decomposes in an acidic region, and it has been conventional wisdom that a decrease in the pH of the reaction solution due to the production of organic acids is unfavorable in terms of reaction yield. Furthermore, CHP decomposes even in an alkaline region. Therefore, the liquid phase oxidation reaction of cumene is generally carried out in a neutral to weakly alkaline region. Therefore, in conventional methods, the reaction was carried out in a state where the reaction solution was kept in the neutral to slightly alkaline range by adding alkali salts such as sodium carbonate and potassium carbonate.

However, in recent years it has been found that the addition of alkali salts and water, which acts as a dispersant, is not necessarily advantageous in terms of reaction yield. Special Publication No. 54-9185 and Special Publication No. 55
- Japanese Patent Publication No. 8502 discloses an oxidation reaction method that does not involve the addition of these third substances and water;
In the method of No. 9185, the relationship between the CHP concentration and the residence time of the reaction solution, which has a large effect on organic acid production, is not clarified, and therefore the reaction time is long even in the high CHP concentration range. The reaction pressure is low and the oxidation rate is low, which requires improvement in industrial production.
In addition, in the method of Japanese Patent Publication No. 55-8502, the CHP concentration in the oxidation reactor is low, and it is inefficient to concentrate this concentration directly in the concentration step, so it is necessary to use a preconcentration column under reduced pressure before entering the concentration step. C using the heat of reaction to
HP must be pre-concentrated, a pre-concentration column must be installed, and there is a limit to the degree of concentration of CHP, and neither method is industrially satisfactory.

[0005]

[Problem to be Solved by the Invention] In the liquid phase oxidation reaction of cumene in the presence of oxygen or oxygen-containing gas,
In addition to major byproducts such as C'nol and A'none, some organic acids such as formic acid and acetic acid are also produced. In the conventional method of adding alkali salts, by-produced organic acids are neutralized and the reaction solution is maintained in a weakly alkaline to neutral range. Therefore, CHP in the reaction solution does not decompose, and stable reaction operation is performed. However, when the oxidation reaction is carried out without the addition of alkaline salts or catalysts as in the present invention, the by-produced organic acid remains in the reaction solution without being neutralized, and the reaction solution contains CHP. It becomes an acidic region where it is easy to decompose. Among these, reactions at high CHP concentrations or at high reaction temperatures produce a large amount of such organic acids as by-products. The organic acid produced as a by-product lowers the pH of the reaction solution, promotes the acid decomposition of CHP, and produces phenol, which is an oxidation inhibitor, as a by-product, leading to a decrease in the oxidation rate and CHP yield.

Therefore, in general, CHP in the final reaction solution is
Efforts have been made to reduce the by-product of organic acids and, ultimately, phenol, by carrying out the oxidation reaction at a low concentration of 20 to 25% by weight or lower, and/or by lowering the reaction temperature. Furthermore, a method of lowering the reaction pressure is also considered to have the effect of preventing the organic acid from accumulating in the reaction solution, for example, by causing the low-boiling point organic acid or its precursor to flow out of the reactor together with the reactor outflow gas. However, from an industrial standpoint, the former method of reacting at low CHP concentrations is
P: Unfavorable from the viewpoint of equipment costs in the enrichment process and utility costs required for enrichment. Furthermore, the latter two methods have the disadvantage that the oxidation rate is slow and the required reactor volume is large.

[0007]

[Means for Solving the Problems] As a result of intensive study on the above-mentioned problems, the present inventors have completed the present invention.

That is, the present invention provides a method for continuously producing cumene hydroperoxide by oxidizing cumene in a liquid phase in the presence of oxygen or an oxygen-containing gas, in which two or more reactions are connected in series. The reaction was carried out in the absence of alkali salts or catalysts using a multistage reactor, and the total reaction solution residence time and reaction solution temperature were each 0.1 in the region where the concentration of cumene hydroperoxide in the reaction solution was 25% by weight or less.
~15 hours, 100 ~ 120 °C, and the total reaction solution residence time and reaction solution temperature in the region exceeding 25% by weight, respectively, for 0.1 ~ 10 hours, 90 ~ 115 °C.
℃, the total residence time of the cumene hydroperoxide reaction solution was 3 to 16 hours, and the reaction pressure was 2.
This is a method for producing cumene hydroperoxide, characterized in that the reaction is carried out under a gauge pressure of ~10 kg/cm2.

By adopting such a method, the present invention suppresses the by-products of organic acids and phenols, and achieves high oxidation rate and high yield of CH without being inhibited by oxidation by these by-products.
The present invention provides a method for producing P.

In the method of the present invention, two or more reactors are connected in series, and the raw material cumene is supplied to the first reactor. As the reaction progresses to the second and third stages, the CHP concentration of the reaction solution increases, and the concentrations of by-product organic acids and phenol also increase. The amount of organic acid produced is highly dependent on the CHP concentration. It is said that it depends on the temperature of the reaction solution, but it also depends on the residence time in the reactor, that is, the reaction time, to an equally or even greater extent. Although it is not clear, this is produced by the oxidation of alcohol and aldehyde produced by organic acids from CHP, and due to the accelerating action of this organic acid, CHP
This is thought to be due to the sequential reaction in which phenol is produced through acid decomposition. Therefore, it is convenient to shorten the reaction time in the high CHP concentration range where organic acids are likely to be generated, especially in CHP concentrations exceeding 25% by weight, so that the organic acids can flow out of the reactor before they are generated. .

According to the studies conducted by the present inventors, C in the reaction solution
The reaction should be carried out so that the total reaction time in the CHP concentration range where the HP concentration exceeds 25% by weight is 0.1 to 10 hours, and the total reaction time in the entire CHP concentration range is 3 to 16 hours. . In the range of 25% by weight or less, the adverse effect on reaction time is not so great, but from an industrial standpoint, a total reaction time of 0.1 to 15 hours is good.

[0012] In addition, in a multistage reaction system using three or more reactors, and when the CHP concentration in the final reactor exceeds 35% by weight, the CHP concentration in the reaction solution is 25% by weight.
The total reaction time in the range exceeding 35% by weight is 0.1 to 6 hours, the total reaction time in the range exceeding 35% by weight is 0.1 to 4 hours, and total CH
It is preferable to conduct the reaction so that the total reaction time in the P concentration range is 3 to 15 hours. In the region of 25% by weight or less, the total reaction time is 0.1 to 0.1% for the reasons mentioned above.
It is better to set it to 15 hours.

[0013] Also, the temperature of the reaction solution is determined from the viewpoint of oxidation rate, etc.
100 in the area where the CHP concentration is 25% by weight or less
~120℃, 9 in the area exceeding 25% by weight
The temperature is preferably 0 to 115°C. Particularly in the CHP concentration range of 35% by weight or more, the temperature is preferably 90 to 110°C. The lower the reaction pressure is, the more preferable it is from the viewpoint of preventing accumulation of organic acids. However, in order to maintain the oxidation rate at a high level, it is necessary to maintain the oxidation rate at a pressure of at least 2 kg/cm
~10kg/cm2 Gauge pressure is good.

[0014] By carrying out the oxidation reaction under these conditions, it is possible to suppress the by-product of organic acids while maintaining the oxidation rate at a high level, and further to greatly reduce the by-product of phenol, which is an oxidation reaction inhibitor. It becomes possible.

[0015] The feed gas is oxygen and/or an oxygen-containing gas, typically air. Further, the amount is supplied such that the oxygen concentration in the reactor outlet gas is 8 vol % or less, preferably 2 to 7 vol %.

[0016]Although the reactor is generally of the bubble column type, it may also be of the stirred tank or stirred bubble column type. Gas blowing devices are usually designed to distribute the gas as uniformly as possible within the reactor. If gas dispersion is insufficient, the gas-liquid contact area will decrease, and the supply of oxygen to the reaction solution will not be able to keep up with the oxygen consumption rate, resulting in a significant reduction in the reaction rate.

[0017]

EXAMPLES The method of the present invention will be explained in more detail with reference to Examples below.

Example 1 Cumene containing 2.6% by weight of CHP was continuously supplied to a first reactor made of stainless steel with an inner diameter of 30 cm and a liquid depth of 2.7 m at a rate of 38 kg/hour. In addition, 1 vol.% of air was added so that the oxygen concentration in the reactor outflow gas was 5 vol%.
Continuously supplied from a 00 μm sintered plate at 108℃,
The reaction was carried out under 6 kg/cm2 gauge pressure. The residence time of the reaction solution was 4 hours, and the CHP, organic acid, and phenol concentrations were 23% by weight and 125 mg, respectively.
/L, and 11 mg/L.

[0019] This reaction solution was poured into a tube with an inner diameter of 20 cm and a depth of 2.7 cm.
29 kg/h was continuously fed to a second reactor made of stainless steel. The reaction was carried out at a reaction temperature of 100° C. and at the same pressure and oxygen concentration in the outflow gas as in the first reactor. The residence time of the second reaction solution and the concentrations of CHP, organic acid, and phenol were 2.5 hours, 30% by weight, and 1% by weight, respectively.
They were 75 mg/L and 16 mg/L.

[0020] Subsequently, the second reaction solution was transferred to a third stainless steel reactor with an inner diameter of 15 cm and a liquid depth of 2.7 m at a rate of 25 kg per hour.
was fed continuously at a rate of The reaction was carried out at a reaction temperature of 98° C. and at the same pressure and oxygen concentration in the effluent gas as in the first reactor. The residence time and concentration of CHP, organic acid, and phenol of the third reaction solution were 2.0 hours and 35% by weight, respectively.
They were 230 mg/L and 22 mg/L.

[0021] Subsequently, the third reaction solution was transferred to a fourth stainless steel reactor with an inner diameter of 10 cm and a liquid depth of 2.7 m at a rate of 10 kg per hour.
was fed continuously at a rate of The reaction was carried out at a reaction temperature of 98° C. and at the same pressure and oxygen concentration in the effluent gas as in the first reactor. The residence time and concentration of CHP, organic acid, and phenol of the fourth reaction solution were 2.0 hours and 40% by weight, respectively.
, 310 mg/L, and 31 mg/L. Continuous operation was continued for about two weeks under the above conditions, and all reactors were able to operate stably.

Example 2 Cumene containing 2.6% by weight of CHP was continuously supplied at a rate of 60 kg/hour to a first reactor made of stainless steel with an inner diameter of 30 cm and a liquid depth of 2.7 m. In addition, 1 vol.% of air was added so that the oxygen concentration in the reactor outflow gas was 5 vol%.
Continuously supplied from a 00 μm sintered plate at 108℃,
The reaction was carried out under 6 kg/cm2 gauge pressure. The residence time of the reaction solution was 2.5 hours, and the CHP, organic acid, and phenol concentrations were 14% by weight and 65mg/L, respectively.
, 6 mg/L.

[0023] This reaction solution was poured into a tube with an inner diameter of 20 cm and a depth of 2.7 cm.
The mixture was continuously fed to a second reactor made of stainless steel at a rate of 31 kg/hr. The reaction was carried out at a reaction temperature of 104° C., and the same pressure and oxygen concentration in the outflow gas as in the first reactor. The residence time and CHP of the second reaction solution, as well as the concentrations of organic acid and phenol, were 2.2 hours, 23% by weight, and 23% by weight, respectively.
They were 120 mg/L and 11 mg/L.

Next, the second reaction solution was transferred to a third stainless steel reactor with an inner diameter of 15 cm and a liquid depth of 2.7 m at a rate of 20 kg per hour.
was fed continuously at a rate of The reaction was carried out at a reaction temperature of 101° C., and the same pressure and oxygen concentration in the outflow gas as in the first reactor. The residence time and concentration of CHP, organic acid, and phenol in the third reaction solution were 2.1 hours, 30% by weight, 170 mg/L, and 16 mg/L, respectively.

[0025] Subsequently, the third reaction solution was transferred to a fourth stainless steel reactor with an inner diameter of 10 cm and a liquid depth of 2.7 m at a rate of 10 kg per hour.
was fed continuously at a rate of The reaction was carried out at a reaction temperature of 98° C. and at the same pressure and oxygen concentration in the effluent gas as in the first reactor. The residence time and concentration of CHP, organic acid, and phenol of the fourth reaction solution were 1.9 hours and 35% by weight, respectively.
, 220 mg/L, and 21 mg/L. Continuous operation was continued for about two weeks under the above conditions, and all reactors were able to operate stably.

Example 3 Cumene containing 2.6% by weight of CHP was continuously supplied to a first reactor made of stainless steel with an inner diameter of 30 cm and a liquid depth of 2.7 m at a rate of 38 kg/hour. In addition, 1 vol.% of air was added so that the oxygen concentration in the reactor outflow gas was 5 vol%.
Continuously supplied from a 00 μm sintered plate, heated at 107°C,
The reaction was carried out under 6 kg/cm2 gauge pressure. The residence time of the reaction solution was 4 hours, and the CHP, organic acid, and phenol concentrations were 22% by weight and 110 mg, respectively.
/L, 10mg/L.

[0027] This reaction solution was poured into a tube with an inner diameter of 20 cm and a depth of 2.7 cm.
29 kg/h was continuously fed to a second reactor made of stainless steel. The reaction was carried out at a reaction temperature of 103° C., and the same pressure and oxygen concentration in the effluent gas as in the first reactor. Residence time and CHP of the second reaction solution, and organic acid,
The concentrations of phenol were 30% by weight, 170 mg/L, and 17 mg/L for 2.5 hours, respectively.

Subsequently, the second reaction solution was transferred to a third stainless steel reactor with an inner diameter of 15 cm and a liquid depth of 2.7 m at a rate of 29 kg per hour.
was fed continuously at a rate of The reaction was carried out at a reaction temperature of 101° C., and the same pressure and oxygen concentration in the outflow gas as in the first reactor. The residence time and concentration of CHP, organic acid, and phenol of the third reaction solution were 1.4 hours and 34 hours, respectively.
They were 5% by weight, 235 mg/L, and 23 mg/L.

Next, the third reaction solution was transferred to a fourth stainless steel reactor with an inner diameter of 10 cm and a liquid depth of 2.7 m at a rate of 17 kg per hour.
was fed continuously at a rate of The reaction was carried out at a reaction temperature of 99° C. and at the same pressure and oxygen concentration in the effluent gas as in the first reactor. The residence time and concentration of CHP, organic acid, and phenol in the fourth reaction solution were 1.1 hours, 39.5% by weight, 300 mg/L, and 30 mg/L, respectively.

Subsequently, the fourth reaction solution was transferred to a fifth stainless steel reactor with an inner diameter of 10 cm and a liquid depth of 2.7 m at a rate of 15 kg per hour.
was fed continuously at a rate of The reaction was carried out at a reaction temperature of 98° C. and at the same pressure and oxygen concentration in the effluent gas as in the first reactor. The residence time and CHP of the fourth reaction solution, as well as the concentrations of organic acid and phenol, were 1.0 hour and 42.5 hours, respectively.
They were 5% by weight, 340 mg/L, and 34 mg/L. Continuous operation was continued for about two weeks under the above conditions, and all reactors were able to operate stably.

Comparative Example 1 The first reactor was operated under the same conditions as in Example 1. Subsequently, the second reactor was operated under the same conditions as the second reactor of Example 1, except that the first reaction liquid was fed at a rate of 8.5 kg/hour. The residence time of the reaction solution was about 12 hours, and the CHP concentration in the reaction solution temporarily rose to about 40 wt%. However, as organic acids and phenols increased over time, the CHP concentration subsequently decreased. After approximately 2 days of continuous operation, the CHP concentration had decreased to 26% by weight. Furthermore, the organic acid and phenol concentrations reached 1600 mg/L and 300 mg/L, respectively, and no tendency to stabilize was observed.

Comparative Example 2 Comparative Example 1 except that the reaction temperature of the second reactor was 98°C.
The reaction was carried out under the same conditions. As in Comparative Example 1, the CHP concentration in the reaction solution temporarily rose to about 37 wt%. However, as organic acids and phenols increased over time, the CHP concentration subsequently decreased. Approximately 5
After continuous operation for one day, the CHP concentration decreased to 25% by weight. In addition, the organic acid and phenol concentrations were each 150
The concentrations reached 0 mg/L and 250 mg/L, and no tendency toward stabilization was observed.

Comparative Example 3 A reaction was carried out under the same conditions as in Example 1, except that the reaction temperature of the second reactor was 120°C. As in Comparative Example 1, the CHP concentration in the reaction solution temporarily rose to about 39 wt%. However, as organic acids and phenols increased over time, the CHP concentration subsequently decreased. After about 2 days of continuous operation, the CHP concentration decreased to 26% by weight. In addition, the organic acid and phenol concentrations were each 1
The concentrations reached 100 mg/L and 120 mg/L, and no tendency toward stabilization was observed.

Comparative Example 4 The first reactor was operated in the same manner as in Example 1 except that the reaction pressure was 0.7 kg/cm2 gauge pressure. Although the operation was stable, the CHP concentration of the reaction solution was 17% by weight.
This value was lower than that of Example 1.

[0035]

[Effects of the Invention] According to the method of the present invention, even in the absence of alkali salts and catalysts, the amount of by-products of organic acids and phenols is small. Therefore, long-term stable operation under high concentration CHP is possible without being inhibited by the oxidation reaction due to these substances. In addition, since the reaction temperature can be set relatively high in a high CHP concentration region, the oxidation rate increases, which leads to a reduction in the reactor volume. Furthermore, since the CHP concentration in the final reaction solution can be increased, the energy required for the CHP concentration system and the equipment cost of the concentrator can be significantly reduced, making it extremely useful for industry.

Claims (6)

[Claims] Claim 1: A method for continuously producing cumene hydroperoxide by liquid-phase oxidation of cumene in the presence of oxygen or an oxygen-containing gas, in which two or more reactors are connected in series. The reaction was carried out in the absence of alkali salts or catalysts, and the total reaction solution residence time and reaction solution temperature in the region where the concentration of cumene hydroperoxide in the reaction solution was 25% by weight or less were 0.1 to 15 hours, respectively. ,
100 to 120°C, and the total reaction solution residence time and reaction solution temperature in the region exceeding 25% by weight were set to 0.1 to 10 hours, respectively, and 90 to 115°C, and the total reaction solution of cumene hydroperoxide was Residence time 3-16
1. A method for producing cumene hydroperoxide, characterized in that the reaction is carried out under a gauge pressure of 2 to 10 kg/cm2. 2. The reaction is carried out using three or more multi-stage reactors connected in series, and the total reaction solution residence time and reaction solution in a region where the concentration of cumene hydroperoxide in the reaction solution is 25% by weight or less. Temperature 0.1-15 hours, 1
The total reaction solution residence time and reaction solution temperature in the range of 00 to 120°C, exceeding 25% by weight and below 35% by weight were changed for 0.1 to 6 hours, and in the range of 90 to 115°C, exceeding 35% by weight. 2. The total residence time of the reaction solution and the temperature of the reaction solution are respectively 0.1 to 4 hours and 90 to 110° C., and the total residence time of the reaction solution of cumene hydroperoxide is 3 to 16 hours. Method. Claim 3: Claim 1, wherein the concentration of cumene hydroperoxide in the final reactor is 50% by weight or less.
Or the method described in 2. 4. The reaction is carried out in four multistage reactors connected in series, and the cumene hydroperoxide concentration, reaction solution residence time, and reaction solution temperature in the first reactor are each set at 25%.
weight% or less, 0.1 to 15 hours and 100 to 120°C,
The cumene hydroperoxide concentration and the reaction liquid temperature in the second reactor are respectively 25% by weight and 30% by weight or less and 95-115°C, and the cumene hydroperoxide concentration and the reaction liquid temperature in the third reactor are respectively 30% by weight. 35% by weight or less and 90 to 110°C, and the total residence time of the reaction liquid in the second reactor and third reactor is 0.1 to 35% by weight.
6 hours, and the cumene hydroperoxide concentration, reaction solution residence time, and reaction solution temperature in the fourth reactor were set at 35% each.
more than 40% by weight, 0.1 to 4 hours and 90% by weight
2. The method according to claim 1, wherein the temperature is 110 DEG C. and the total residence time of the cumene hydroperoxide reaction solution is 3 to 16 hours. 5. The reaction is carried out in four multi-stage reactors connected in series, and the cumene hydroperoxide concentration and reaction liquid temperature in the first reactor are set to 18% by weight or less and 1% by weight or less, respectively.
00 to 120°C, the cumene hydroperoxide concentration and the reaction liquid temperature in the second reactor were set to more than 18% by weight and less than 25% by weight, and 95 to 115°C, respectively, and the total reaction in the first and second reactors was Liquid residence time 0.1-15
In addition, the cumene hydroperoxide concentration and reaction liquid temperature in the third reactor were determined to be more than 25% by weight and less than 30% by weight and 90 to 110°C, respectively, and the cumene hydroperoxide concentration and reaction liquid temperature in the fourth reactor were determined respectively. 30
more than 35% by weight and 90-105℃, 3rd
The total residence time of the reaction liquid in the reactor and the fourth reactor is 0.
Claim 1: 1 to 10 hours, and the total residence time of the cumene hydroperoxide reaction solution is 3 to 16 hours.
Method described. 6. The reaction is carried out using five multistage reactors connected in series, and the cumene hydroperoxide concentration, reaction solution residence time, and reaction solution temperature in the first reactor are each set at 25%.
% by weight or less, 0.1-15 hours and 100-120°C
, the cumene hydroperoxide concentration and the reaction liquid temperature in the second reactor are more than 25% by weight and less than 30% by weight and 95 to 115°C, and the cumene hydroperoxide concentration and the reaction liquid temperature in the third reactor are each 30% by weight. % to 35% by weight or less and 90 to 110°C, and the total residence time of the reaction liquid in the second reactor and third reactor is 0.1 to 35% by weight.
5 hours, and the cumene hydroperoxide concentration, reaction solution residence time, and reaction solution temperature in the fourth reactor were adjusted to 35 minutes, respectively.
More than 40% by weight, 0.1 to 3 hours and 90% by weight
~110°C, and the cumene hydroperoxide concentration, reaction liquid residence time, and reaction liquid temperature in the fifth reactor were set at 40°C, respectively.
more than 45% by weight, 0.1 to 2 hours and 90% by weight
2. The method according to claim 1, wherein the temperature is 110 DEG C. and the total residence time of the cumene hydroperoxide reaction solution is 3 to 16 hours.