JP5614105B2 - Method for producing ketazine and hydrated hydrazine - Google Patents

Description

  The present invention relates to an industrial process for producing ketazine and hydrated hydrazine.

  Ketazine is generally synthesized by oxidizing ammonia with an oxidizing agent such as sodium hypochlorite or hydrogen peroxide in the presence of a ketone. Non-Patent Document 1 describes a process of synthesizing ketazine from hydrogen peroxide, ammonia and a ketone, and further producing hydrated hydrazine by hydrolysis of ketazine.

  In this process, an aqueous solution containing acetamide and sodium phosphate is used as a working fluid to synthesize ketazine, and methyl ethyl ketone is used as a ketone. In this process, since the activity of the working fluid gradually decreases due to continuous operation, it is necessary to prepare and replenish a new working fluid in order to stably produce ketazine. However, preparation and replenishment of a new hydraulic fluid generally requires complicated and complicated operations.

  Therefore, Patent Document 1 reports a method in which the working fluid is purified with an ion exchange resin to remove impurities that adversely affect the reaction, and then recycled and reused. In this method, ketazine is produced in a high yield by removing by-products from the working fluid to be recycled and reused. However, there is no description about the influence of the ketazine concentration in the residual reaction liquid and the working liquid when ketazine is continuously produced by the same reaction apparatus.

  Further, Patent Document 2 reports a method of adjusting the water concentration in the working fluid by adding a substance azeotropic with water to the working fluid separated from ketazine and distilling it. In this method, ketazine is produced in a high yield by keeping the water concentration in the working fluid within a certain range while suppressing thermal deterioration of the working fluid component that is circulated and reused. However, the use of an azeotropic substance has a large economic burden, and it takes time to treat water mixed with the azeotropic substance.

Japanese Patent No. 3539433 Japanese Patent No. 4131140

Kirkusmer 3rd edition, volume 12, pages 734-755

When ketazine synthesis is continuously performed using the same reaction apparatus, the reaction liquid after ketazine synthesis is extracted from the reaction apparatus as much as possible, and sent to a step of separating the produced ketazine and the working liquid. However, it is difficult to completely extract the reaction solution in the reaction apparatus in a short time, or it is industrially impossible to wash the reaction apparatus for each batch. It was mixed in the reaction solution of the batch, preventing stabilization of the ketazine yield of the next batch.
The present invention solves the problems in the prior art, and when performing continuous ketazine synthesis using the same reaction apparatus, it is substantially free from the influence of the residual reaction liquid in the previous batch and supplemented with a new hydraulic fluid. The purpose of the present invention was to stably produce ketazine in a high yield.

The present inventors can stably produce ketazine at a high yield by adjusting the ketazine concentration of the hydraulic fluid before adding hydrogen peroxide, ammonia and ketone to the hydraulic fluid within a specific range. As a result, the present invention has been completed.
That is, the present invention
(A) synthesizing ketazine from hydrogen peroxide, ammonia and ketone in the presence of a working fluid;
(B) separating the produced ketazine and the working fluid and distilling the separated working fluid;
(C) a step of circulating and reusing the distilled working fluid in step (a);
A method for producing ketazine comprising:
In the step (a), the present invention relates to a method for producing ketazine, characterized in that the concentration of ketazine in a working fluid before adding hydrogen peroxide, ammonia and ketone is adjusted to 0.1 to 3.0% by weight.

  According to the method for producing ketazine of the present invention, it is not necessary to completely extract the reaction residual liquid in step (a), the reaction liquid extraction time can be shortened, and the ketazine concentration of the working liquid can be adjusted. In addition, the working fluid distilled in step (b) can be reused, and ketazine can be stably produced in a high yield without substantially replenishing the new working fluid. Therefore, its industrial value is great.

  Step (a) of the present invention is a step of synthesizing ketazine from hydrogen peroxide, ammonia and a ketone in the presence of a working fluid. In step (a), the ketazine concentration of the working fluid before adding hydrogen peroxide, ammonia and ketone is adjusted, and then hydrogen peroxide, ammonia and ketone are added to the working fluid to synthesize ketazine. Preferably, the working liquid in step (c) is mixed with the reaction residual liquid in the previous batch in the reaction apparatus to prepare the ketazine concentration of the working liquid. By using the hydraulic fluid of the step (c), it is not necessary to replenish the new hydraulic fluid, so that the industrial significance is great. In addition to the working fluid in step (c), the working fluid before adding hydrogen peroxide, ammonia and ketone may be mixed with a working fluid purified by a known method, a new working fluid, or the like.

  In step (a), the ketazine concentration of the hydraulic fluid before adding hydrogen peroxide, ammonia and ketone is adjusted to 0.1 to 3.0% by weight, preferably 0.5 to 2.7% by weight. When the ketazine concentration of the hydraulic fluid exceeds 3.0% by weight, the reaction is remarkably inhibited and the ketazine yield is lowered. On the other hand, since the reaction is hardly inhibited at 0.1% by weight or less, further reduction of the ketazine concentration is not economical. In the step (a), as a method for adjusting the ketazine concentration of the hydraulic fluid before adding hydrogen peroxide, ammonia and ketone, for example, the hydraulic fluid of the step (c) is added to the reaction residual liquid of the previous batch in the reactor. A method of adjusting the mixing amount of the working fluid in the step (c) so that the ketazine concentration of the working fluid in the reaction device is within the above range when mixing.

  As the hydrogen peroxide used in the present invention, a 30 to 90% by weight aqueous hydrogen peroxide solution which is a normal commercial product can be used. Peroxide solution stabilizers such as phosphoric acid, pyrophosphoric acid, citric acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, or ammonium salts or alkali metals of these acids may be added to hydrogen peroxide. The amount of these stabilizers is 1 to 100 ppm, preferably 5 to 25 ppm, of the total amount of the reactant and the working fluid.

  Ammonia may be introduced as aqueous ammonia or ammonia gas. It is preferable to introduce it as ammonia gas because the ketazine yield can be improved while keeping the water concentration in the reaction system low.

The ketone is R ₁ R ₂ C═O (where R ₁ and R ₂ are alkyl groups containing 1 to 12 carbon atoms, branched alkyl groups or cycloalkyl groups containing 3 to 12 carbon atoms, 6 Represents an aromatic group containing ˜12 carbon atoms or a linear or branched alkylene group containing 3-12 carbon atoms, these groups being halogen, NO ₂ groups, hydroxy groups, alkoxy groups or carboxylic acid esters, Preferably, it may be substituted by Cl, NO ₂ or CH ₃ O. R ₁ and R ₂ may be the same or different from each other. Specific examples include acetone, 2-pentanone, 3-pentanone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl cyclohexyl ketone, acetophenone, benzophenone, cyclobutanone, cyclopentanone, and cyclohexanone. In particular, it is preferable to use one or more selected from the group consisting of acetone, methyl ethyl ketone and methyl isobutyl ketone in order to obtain hydrazine hydrate from ketazine.

  The ketone, ammonia and hydrogen peroxide as reaction starting materials can be used in any amount, but the ketone is 0.2 to 5 mol, preferably 1.5 to 4 mol, and ammonia is 1 mol of hydrogen peroxide. 0.1 to 10 mol, preferably 1.5 to 4 mol can be used. The amount of the working fluid is in the range of 0.1 to 1 kg per mole of hydrogen peroxide.

  The working fluid can be prepared by bringing into solution a compound that maintains a ketazine synthesis reaction consisting of one or more compounds selected from organic or inorganic amides, ammonium salts, nitriles or mixtures thereof. . Examples of preferred amides are formamide, acetamide, monochloroacetamide and propionamide. Among the ammonium salts, formate, acetate, monochloroacetate, propionate and the like are preferable. As the nitrile, acetonitrile, propionitrile and the like are preferable.

Moreover, an organic arsenic compound can be used for a hydraulic fluid. Specifically, R′R ″ As (═O) OH or R ′ ″ As (═O) (OH) ₂ (where R ′, R ″, R ′ ″ are alkyl groups or aromatics) Organic arsonic acid and organic arsinic acid represented by a group). Specific examples include methylarsonic acid, ethylarsonic acid, phenylarsonic acid, methylphenylarsonic acid, methoxyphenylarsonic acid, carboxyphenylarsonic acid, chlorophenylarsonic acid, nitrophenylarsonic acid, cacodylic acid, diethylarsinic acid, diphenylarsinic acid Etc. Preferred organic arsenic compounds are cacodylic acid, phenylarsonic acid, methylarsonic acid, p-nitrophenylarsonic acid, diphenylarsinic acid. These acids may be ammonium salts.

  When using an organic arsenic compound, it is preferable to use a carboxylic acid. Examples of carboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, pentanoic acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, dodecanoic acid, linolenic acid, oleic acid and the like. In particular, formic acid, acetic acid, propionic acid, and among them, acetic acid is preferable. Carboxylic acid increases the ammonia concentration in the working fluid during the reaction and contributes to an improvement in yield. The concentration of the carboxylic acid in the working fluid is preferably 5 to 35% by weight, more preferably 5 to 25% by weight.

  The hydraulic fluid is preferably a mixed solution of water and alcohol. As the alcohol, it is preferable to use a saturated aliphatic alcohol having 1 to 6 carbon atoms, particularly 1 to 2 carbon atoms. Moreover, C2-C5 diol can also be used conveniently. Examples include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentanediol.

  The amount of the amide, acid, ammonium salt, or nitrile introduced into the mixture of water and alcohol is preferably 30 to 80% by weight in the working fluid before the reaction. The amount of the organic arsenic compound is preferably 20 to 45% by weight, more preferably 25 to 40% by weight. The organic arsenic compound is improved in yield by being present at a high concentration in the working fluid, but if it is present in an excessive amount, a solid is precipitated and hinders the reaction.

  The contact between the reactant containing hydrogen peroxide, ammonia, and methyl ethyl ketone and the working fluid can be performed by any method. Preferably, the operation is in a homogeneous medium or a medium in which each reactant can be solubilized enough to obtain ketazine. Although the said reaction can be performed in a wide temperature range, Preferably it is 30-110 degreeC, More preferably, it is 30-70 degreeC. This reaction can be carried out at any pressure, but it is easier to operate at atmospheric pressure. Each reactant can be added to the hydraulic fluid simultaneously or individually in any order. As the reaction apparatus, a stirring and mixing tank or a fluidized tank in which the contact between each reactant and the working liquid is favorably performed is preferable.

  In the step (b), the ketazine obtained from the above reaction and the working fluid can be separated by a known method such as liquid-liquid extraction or distillation, or a method combining these. A liquid-liquid separation method using a mixer / settler or a centrifuge is preferable.

  Before reusing the working fluid separated from ketazine, the water derived from the reaction raw material and the water produced by the reaction are removed by distillation. As operating conditions when using a distillation column, the temperature is 60 to 129 ° C, preferably 60 to 100 ° C, and the pressure is 1 to 67 kPa, preferably 1 to 33 kPa, at the top of the column. The distillation column preferably has 5 to 50 theoretical plates, and the working fluid is preferably fed to the 3rd to 20th stages from the bottom. The water concentration in the working fluid before the reaction is 1 to 15% by weight, preferably 6 to 14% by weight. When the hydraulic fluid contains an organic arsenic compound, the compound is precipitated when the water concentration is low, and the yield is reduced when the concentration is high.

  In step (c), the working fluid distilled in step (b) is recycled and reused in step (a). Preferably, impurities in the working fluid are removed at any stage of circulating and reusing the working fluid. The removal of impurities includes purification with a cation exchange resin and / or an anion exchange resin. In addition, it is not necessary to refine | purify the whole quantity of the distilled working fluid, and what is necessary is just to refine | purify a part. The amount of working fluid to be purified depends on the amount of impurities in the working fluid, but the amount of impurities in the working fluid depends on the synthesis conditions of ketazine and the amount of impurities already present in ammonia, hydrogen peroxide and ketone. Depends on.

  Hydrated hydrazine is obtained by hydrolyzing ketazine. As a hydrolysis method, a constant ratio of ketazine and water are continuously supplied to a distillation column to perform a hydrolysis reaction under pressure to obtain a ketone as a distillate and a hydrazine aqueous solution as a bottom. The method is common.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

<Analysis conditions>
The ketazine concentration in the working fluid was determined by a redox titration method. 3 ml of the working fluid was sampled, hydrolyzed to hydrazine with 10 ml of 2 mol / L sulfuric acid, and then heated to 60 ° C. while reducing the pressure to 4 kPa to remove by-produced ketone. Then, after excess sulfuric acid was neutralized with a 4 mol / L sodium hydroxide aqueous solution, titration was performed with a 0.05 mol / L iodine aqueous solution in the presence of sodium hydrogen carbonate. And the ketazine density | concentration in a hydraulic fluid was calculated | required from the amount of iodine required for the end point.
The ketazine yield was determined from the ratio of the amount of ketazine produced in the reaction and the supply amount of hydrogen peroxide as a raw material. The amount of ketazine produced in the reaction was determined from the difference between the amount of ketazine in the reaction solution and the amount of ketazine in the supplied working solution by determining the ketazine concentration in the reaction solution by the same oxidation-reduction titration method as described above.

Example 1
Hydraulic fluid separated and distilled from the reaction liquid for ketazine synthesis (composition of hydraulic fluid: 38.8 wt% ammonium cacodylate, 1.2 wt% ammonium monomethylarsonate, 16.2 wt% ammonium acetate, 8.5 wt% water) %, Ethylene glycol 34.8 wt%, ketazine 0.5 wt%) was charged into a stainless steel reactor having an inner diameter of 2.8 m and a height of 5.95 m. Next, the mixture was heated to 60 ° C. with vigorous stirring using a 1000 kL / h circulation pump, and 850 kg of ammonia was blown in over 20 minutes to saturate the ammonia in the working fluid. Thereafter, 2070 kg of 60 wt% aqueous hydrogen peroxide and 7000 kg of 80 wt% methyl ethyl ketone were fed over 40 minutes, while 1900 kg of ammonia was blown in over 50 minutes. The reaction was terminated by stirring for another 30 minutes after the end of the ammonia blowing. Thereafter, when the reaction solution was extracted, 700 kg of a residual reaction solution remained in the reactor.

  The working liquid is added to the reaction residual liquid, and the concentration of ketazine in the working liquid before adding hydrogen peroxide solution, methyl ethyl ketone, and ammonia (hereinafter sometimes referred to as concentration A) is 1.3% by weight. Prepared. Thereafter, the reaction was carried out under the same conditions as described above to produce ketazine. The yield of ketazine obtained by the reaction was 86.5 mol% with respect to the supplied hydrogen peroxide. The details of the working fluid and reaction raw materials and the results are shown in Table 1.

Examples 2-5
The same as in Example 1 except that the composition of hydraulic fluid, the supply amount of hydraulic fluid and reaction raw materials, and the amount of residual reaction liquid in the reactor were changed to adjust the ketazine concentration (concentration A) to the concentration shown in Table 1. Went to. The details of the working fluid and reaction raw materials and the results are shown in Table 1.

Comparative Example 1
The same as in Example 1 except that the composition of hydraulic fluid, the supply amount of hydraulic fluid and reaction raw materials, and the amount of residual reaction liquid in the reactor were changed to adjust the ketazine concentration (concentration A) to the concentration shown in Table 1. Went to. The details of the working fluid and reaction raw materials and the results are shown in Table 1.

  As shown in Examples 1 to 5, the ketazine concentration after completion of the reaction is reduced by setting the ketazine concentration (concentration A) in the working fluid before contacting hydrogen peroxide, ammonia and ketone to 2.7% by weight or less. It was found that the rate stably showed a high level of 80 mol% or more. Furthermore, even if the content of the organic arsenic compound that exhibits catalytic action in the working fluid to be recycled is changed, it is found that ketazine can be produced in a high yield by adjusting the ketazine concentration (concentration A) in the working fluid. It was. The present invention is an invention that can easily prevent a decrease in yield due to a change in the amount of residual reaction liquid in the previous batch or a change in the composition of the working fluid by adjusting the ketazine concentration of the working fluid before the addition of the reaction raw material to a specific range. Yes, its industrial value is great.

Claims (5)

(A) synthesizing ketazine from hydrogen peroxide, ammonia and ketone in the presence of a working fluid;
(B) separating the produced ketazine and the working fluid and distilling the separated working fluid;
(C) a step of circulating and reusing the distilled working fluid in step (a);
A method for producing ketazine comprising:
In step (a), the ketazine concentration of the hydraulic fluid before adding hydrogen peroxide, ammonia and ketone is adjusted to 1.3 to 3.0% by weight , and before adding the hydrogen peroxide, ammonia and ketone, A method for producing ketazine, wherein the working fluid is obtained by mixing the working fluid of step (c) with the reaction residual solution of the previous batch .   The method according to claim 1, wherein the ketone is one or more selected from the group consisting of acetone, methyl ethyl ketone and methyl isobutyl ketone. The method according to claim 1 or 2 , wherein the hydraulic fluid contains an organic arsenic compound. The method according to any one of claims 1 to 3, hydraulic liquid contains a carboxylic acid. A method for producing a hydrazine hydrate by hydrolyzing the ketazine produced by the method according to any one of claims 1 to 4 .