JPS634529B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for removing salts from a hydroperoxide decomposition neutralization solution. Oxidizing an alkyl aromatic hydrocarbon having a tertiary carbon, such as kyumene, cymene, isopropylbenzene, etc. to produce a hydroperoxide,
A non-aqueous solution containing the hydroperoxide, such as an organic solvent solution consisting of acetone, methyl isobutyl ketone, benzene, and a mixture thereof, is treated with sulfuric acid or sulfuric anhydride for acid catalytic decomposition, and the decomposition reaction solution is neutralized, and then the reaction is carried out. It is well known to produce aromatic hydroxides such as phenols, cresols, resorcinols and/or hydroquinones. In the above method, typical methods for neutralizing the acid catalytic cracking reaction solution include NaOH, KOH,
This is a neutralization method using a basic substance such as NH ₃ or alkali phenolates, and in most cases, an aqueous solution of the basic substance is added to the decomposition reaction solution, or the basic substance and water are added separately, and a neutralized salt is added. A method is used in which the salt is dissolved in water and then separated to remove the neutralized salt-containing aqueous layer. However, with this method, although most of the salts such as neutralized salts can be removed as an aqueous layer,
A small amount of water layer is trapped in the oil layer after separation, and as a result, a trace amount of salt is mixed into the oil layer.The oil layer after neutralization may be distilled to recover the solvent, or When attempting to obtain the desired product, neutralized salts precipitate in the distillation column, which may clog the column and have a major impact on the manufacturing process after neutralization. Therefore, for example, it is possible to add water to the oil layer after separating and removing the neutralized salt-containing aqueous layer and wash it, but in this case, a washing device is required and the operation is complicated. In addition, since a large amount of washing water is used, problems such as subsequent wastewater treatment arise. For this reason, the present inventors have investigated various methods for removing salts from the hydroperoxide decomposition and neutralization solution. It was discovered that by separating the neutralized salt-containing water contained in the oil layer and separating and removing it, salts such as the neutralized salt in the oil layer can be easily removed, and the present invention has been achieved. That is, the present invention provides a hydroperoxide decomposition neutralized solution obtained by neutralizing an acid catalytic decomposition reaction solution of a hydroperoxide of an alkyl aromatic hydrocarbon having tertiary carbon with sulfuric acid or sulfuric anhydride with a basic substance in the coexistence of water. In the method of removing the generated neutralized salt, the decomposition reaction liquid is separated into an oil layer and an aqueous layer, the aqueous layer is removed, the oil layer is further cooled, and the generated aqueous layer is separated and removed. This is a method for removing salts from a hydroperoxide decomposition and neutralization solution, which is characterized by the following. Neutralization of the acid catalytic cracking reaction solution and separation and removal of the separated aqueous layer are performed by conventionally known methods and are not particularly limited. For example, liquid separation treatment after neutralization (hereinafter 1)
(referred to as stage separation) is usually carried out at 40 to 70°C,
In this case, the lower the temperature, the worse the separation efficiency tends to be (the content of residual salts in the oil layer increases). In the present invention, the oil layer separated in the one-stage separation process is cooled to a lower temperature than in the one-stage separation process. Although the degree of cooling depends on each condition, it is usually cooled to about 10° C. or more, preferably 15° C. or more lower than the one-stage liquid separation treatment temperature. By performing such cooling, the water containing salts such as neutralized salts entrapped in the oil layer is separated, and the water layer is separated again into the water layer and the oil layer. is called two-stage separation). Thus, by adding a simple operation to the oil layer after the first stage separation, it becomes possible to very easily remove salts such as neutralized salts in the oil layer (organic solvent solution containing decomposition reaction products). In carrying out the method of the present invention, the mixture of the oil layer and water layer to be separated is passed through a coalescer, such as a glass fiber or a stainless steel fiber, before the first-stage separation, the second-stage separation, or both. Passing the oil through a tube filled with fibrous material (including thin wires) is an effective means to coalesce the microscopic water layer particles in the oil layer and proceed with the subsequent liquid separation process quickly and efficiently. It is. The present invention will be explained below using examples. In the examples, % and parts indicate weight units. Comparative Examples 1 to 3 A decomposition reaction solution containing resorcinol and hydroquinone obtained by treating 100 parts of a methyl isobutyl ketone (MIBK) solution containing 20% diisopropylbenzene dihydroperoxide with 2 parts of a 0.5% anhydrous sulfuric acid acetone solution was treated as follows. A neutralization separation process was performed using the method. Decomposition reaction solution and 0.02% NaOH aqueous solution, respectively.
It was continuously supplied to the neutralization layer at 7.0Kg/Hr and 1.7Kg/Hr, and the neutralization reaction liquid was continuously extracted from the neutralization tank and continuously subjected to liquid separation treatment in a liquid separation tank. At this time, the average residence time of the oil layer in the neutralization tank was 5 minutes, and the average residence time of the oil layer in the separation tank was 15 minutes.
In addition, in order to adjust the specific gravity of the aqueous layer during the separation process, mirabilite is added to the NaOH aqueous solution supplied to the neutralization tank so that the mirabilite content in the aqueous solution becomes 3 to 5%, or A part of the separation water separated from the liquid tank was recycled and adjusted. Under these conditions, the temperature of each separation tank is 60℃.
℃, 40℃, and 15℃, and the concentration of Glauber's salt in the resulting decomposed and neutralized oil layer was measured, and the results shown in the table below were obtained.

[Table] From the above results, when neutralization is performed using the one-stage separation method, the lower the separation treatment temperature is, the higher the mirabilite concentration in the decomposed and neutralized oil layer tends to be. It was hot. The concentration of mirabilite in the oil layer referred to here is the value obtained by converting all compounds having -Na groups into mirabilite. (All subsequent values also show converted values.) Examples 1 to 3, Comparative Example 4 Using the same decomposition reaction solution as used in Comparative Example 1,
Neutralization and liquid separation were carried out in the following manner. Similar to the method of Comparative Example 1, the decomposition reaction solution and 0.02%
NaOH aqueous solution 7.0Kg/Hr and 1.7Kg/Hr respectively
was continuously supplied to the neutralization tank. The neutralized reaction liquid from the neutralization layer was continuously drawn out to a liquid separation tank (first stage liquid separation tank), and was continuously subjected to liquid separation treatment in the liquid separation tank. The separated oil layer was cooled with a cooler and continuously transferred to another separation tank (second stage separation tank), and the generated water layer was separated from the oil layer. The temperature of each tank was controlled at 60°C in the neutralization layer and the first stage separation tank, and 60°C (Comparative Example 4), 40°C (Example 1), and 30°C (in the second stage separation tank), respectively. The degree of cooling of the cooler was controlled so that the temperature was 15°C (Example 2) and 15°C (Example 3). In a stable state, the oil layer residence time in the neutralization tank, first-stage separation tank, and second-stage separation tank is 5 minutes each.
It was 15 minutes and 10 minutes. 1st stage separation tank and 2nd stage separation tank
A portion of the separated water separated from the stage separation tank was mixed with NaOH and Na ₂ SO ₄ as in Comparative Example 1.
Water, NaOH and/or Na ₂ SO ₄ were added to adjust the concentration to 0.02% and 3 to 5%, and the mixture was recycled and supplied to the neutralization tank as NaOH water for neutralization. A part of the separated water was also removed from the system. The mirabilite contents in the decomposed and neutralized oil layers obtained under these conditions after each liquid separation treatment were as shown in the table below.

[Table] Examples 4 to 6, Comparative Example 5 The oxidation reaction oil layer containing 20% cymene hydroperoxide obtained by air oxidizing m-, p-cymene mixture in the presence of an alkali was washed with an aqueous sodium carbonate solution. Thereafter, the mixture was concentrated under reduced pressure and the terminally reacted cymene was distilled off to obtain a concentrated oil containing 60% cymene hydroperoxide, which was subjected to a decomposition reaction using 0.5 parts of sulfuric acid per 100 parts of the concentrated oil. Examples 1 to 3 were carried out using the obtained decomposition reaction solution and 0.4% NaOH aqueous solution.
Neutralization and liquid separation were performed in the same manner as above. The results are shown in the table below.

[Table] Examples 7 to 9, Comparative Example 6 The oxidation reaction oil layer containing 20% cumene hydroperoxide obtained by air oxidation of cumene in the presence of an alkali was washed with an aqueous sodium carbonate solution and concentrated under reduced pressure. A concentrated oil containing 60% of cumene hydroperoxide was obtained by distilling off the unreacted cymene, and a decomposition reaction was carried out using 0.5 part of sulfuric acid per 100 parts of the concentrated oil. The resulting cracked reaction oil and 0.4%
Neutralization and liquid separation were carried out using a NaOH aqueous solution in the same manner as in Examples 1 to 3. The results are shown in the table below.

[Table] Example 10 In the methods of Examples 1 to 3, a coalescer made of a SUS or glass cylinder surrounded by a net made of SUS fine wires or filled with glass fibers supported by polypropylene resin was neutralized. If it is installed between the tank and the first-stage separation tank and the decomposition-neutralization reaction liquid is passed through this at a rate of 0.5 to 20 mm/sec, the residence time in the first-stage separation tank can be shortened from 15 minutes to 10 minutes.
The concentration of mirabilite in the first-stage separated oil layer was also reduced from 120 ppm without a coalescer to 80 ppm. Similarly, in the case of Examples 4 to 6,
It decreased from 250 ppm to 170 ppm, and from 200 ppm to 140 ppm in the case of Examples 7 to 9. Example 11 In the methods of Examples 1 to 3, a coalescer similar to Example 10 was provided after the separated oil layer after the first stage separation was cooled with a cooler and before being supplied to the second stage separation tank. When passing through the separated oil layer after the first stage separation, the residence time in the second stage separation tank could be shortened from 10 minutes to 5 minutes, and the concentration of mirabilite in the second stage separation tank could be reduced from 10 to 10 minutes.
We were able to reduce it to 15ppm. Examples 12-14, Comparative Example 7 A decomposition reaction solution containing resorcinol and hydroquinone obtained by treating diisopropylbenzene dihydroperoxide with anhydrous sulfuric acid was neutralized and separated in the same manner as in Examples 1-3. However, in this example, similarly to Examples 10 and 11, coalescers similar to those used in Example 10 were installed in front of the first-stage separation tank and the second-stage separation tank, respectively. In this example, the liquid residence time in each liquid separation tank is as follows.
It was possible to shorten it in the same way as 11. Furthermore, the separation tank temperature and the Glauber's salt concentration in each oil layer obtained by this method were as shown in the table below.

【table】

Claims (1)

[Scope of Claims] 1 Hydroperoxide decomposition neutralization obtained by neutralizing the acid catalytic decomposition reaction solution of hydroperoxide of an alkyl aromatic hydrocarbon having tertiary carbon with sulfuric acid or sulfuric anhydride with a basic substance in the coexistence of water. From the liquid
In the method of removing the generated neutralized salt, the decomposition reaction solution is separated into an oil layer and an aqueous layer, and the aqueous layer is removed;
A method for removing salts from a hydroperoxide decomposition and neutralization solution, characterized in that the oil layer is further cooled and the generated water layer is separated and removed. 2. The method according to claim 1, characterized in that, before the liquid separation process, the mixture of the oil layer and the water layer to be subjected to the liquid separation process is passed through a coalescer in advance. 3. The method according to claim 2, wherein the coalescer is a filling of glass fiber or stainless fiber.