CN111675656B - Continuous production method of bromochlorohydantoin - Google Patents
Continuous production method of bromochlorohydantoin Download PDFInfo
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- CN111675656B CN111675656B CN202010698348.8A CN202010698348A CN111675656B CN 111675656 B CN111675656 B CN 111675656B CN 202010698348 A CN202010698348 A CN 202010698348A CN 111675656 B CN111675656 B CN 111675656B
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D233/00—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings
- C07D233/54—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members
- C07D233/66—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D233/72—Two oxygen atoms, e.g. hydantoin
- C07D233/80—Two oxygen atoms, e.g. hydantoin with hetero atoms or acyl radicals directly attached to ring nitrogen atoms
- C07D233/82—Halogen atoms
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/141—Feedstock
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Abstract
The invention discloses a continuous production method of bromochlorohydantoin, belonging to the technical field of disinfectant production and comprising the following steps: synthesizing 5, 5-dimethyl hydantoin, namely 5, 5-dimethyl hydantoin, removing ammonia in water to prepare bromochlorohydantoin. The invention uses water, ammonia gas, carbon dioxide and acetone cyanohydrin as raw materials to synthesize 5, 5-dimethyl hydantoin; introducing inert gas into the 5, 5-dimethyl hydantoin aqueous solution to remove dissolved ammonia; adding 5, 5-dimethylhydantoin and inorganic base into a reaction kettle, cooling, introducing bromine and chlorine to perform a bromochlorination reaction, centrifugally drying the reaction material after the reaction is finished, and drying to prepare powdery bromochlorohydantoin. According to the invention, the dissolved ammonia in the 5, 5-dimethylhydantoin aqueous solution is removed by the inert gas, and then the bromochlorohydantoin is synthesized, so that the production steps are reduced, the production cost and the potential safety hazard are reduced, and meanwhile, the continuous production from the synthesis of the dimethylhydantoin to the bromochlorohydantoin is realized by linking all the procedures by adopting the conveying pipeline.
Description
Technical Field
The invention belongs to the technical field of disinfectant production, and particularly relates to a continuous production method of bromochlorohydantoin.
Background
The bromochlorohydantoin is a specific disinfectant, and the residue 5, 5-dimethylhydantoin after the bromochlorohydantoin has the disinfection and sterilization effects can be rapidly degraded into ammonia and carbon dioxide under natural conditions, has small influence on the environment, and is a water treatment chemical advocated and encouraged by the nation. It is widely used in industrial water treatment, flower and seed disinfection, sterilization, breeding industry, fruit preservation and other fields.
At present, the existing production of the bromochlorohydantoin is mainly synthesized by taking 5, 5-dimethylhydantoin, inorganic base, chlorine and bromine as raw materials, has high yield and good product quality, and is mainly used by domestic bromochlorohydantoin production enterprises. However, since 5, 5-dimethylhydantoin needs to be synthesized in advance and then reacts with inorganic base, chlorine and bromine through bromine chlorination to generate bromochlorohydantoin, a continuous production mode cannot be formed, and the defects of complicated production steps and high production cost exist.
Disclosure of Invention
The invention aims to provide a continuous production method of bromochlorohydantoin, and aims to solve the technical problems of complicated production steps and high production cost in the prior art.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
a continuous production method of bromochlorohydantoin comprises the following steps:
s1: preparation of 5, 5-dimethylhydantoin:
A. acetone cyanohydrin and water were mixed in a ratio of 1: adding the mixture into a mixing tank at a ratio of 1-1:1.5 respectively for mixing to obtain a mixed solution of acetone cyanohydrin and water;
B. introducing steam into a reactor jacket, introducing carbon dioxide and ammonia gas from the bottom of the reactor, and introducing a mixed solution of acetone cyanohydrin and water from the top of the reactor to highly disperse a gas phase in a liquid phase for reaction;
C. the mixed material flows into a synthesis reaction kettle from the bottom of the reactor; introducing steam into a jacket of a synthesis reaction kettle, controlling the reaction temperature of the materials at 60-80 ℃, and the reaction time at 2.5-4 hours to prepare a 5, 5-dimethylhydantoin aqueous solution after the reaction is finished;
s2: ammonia removal from 5, 5-dimethylhydantoin aqueous solution:
carrying out dry top-bottom-45 m high-speed transformation by introducing inert gas into the 5, 5-dimethylhydantoin aqueous solution in the synthesis reaction kettle at the inert gas introduction speed of 40m, and displacing ammonia in the 5, 5-dimethylhydantoin aqueous solution in the synthesis reaction kettle; detecting that the ammonia content in the 5, 5-dimethyl hydantoin aqueous solution in the synthesis reaction kettle is less than 0.5-1.0 percent, and finishing the ammonia removal process;
s3: preparing bromine chlorine hydantoin:
(1) adding a 5, 5-dimethylhydantoin aqueous solution and water in a synthesis reaction kettle into a dissolution reaction kettle, introducing a cooling medium into a jacket of the dissolution reaction kettle for cooling, simultaneously adding liquid inorganic base into the dissolution reaction kettle for continuously cooling, and transferring a mixture of dimethylhydantoin and inorganic base into a halogenation synthesis reaction kettle after the temperature of the mixture is reduced to 20-25 ℃;
(2) introducing bromine and chlorine gas into a halogenation synthesis reaction kettle to carry out a bromine chlorination reaction, and controlling the reaction temperature to be 25-30 ℃ to carry out the reaction;
the molar ratio of the 5, 5-dimethylhydantoin to the inorganic base to the bromine is 1: 2.5-3.5: 1.0-2.0;
(2) centrifuging and drying after the completion of the bromochlorination reaction to obtain bromochlorohydantoin;
and the continuous production from the synthesis of dimethyl hydantoin to the synthesis of bromochlorohydantoin is realized by linking the procedures in the steps through a conveying pipeline.
Preferably, after step S1 is completed, the obtained 5, 5-dimethylhydantoin aqueous solution is subjected to replacement of free ammonia in the solution by inert gas, and the ammonia content in the final aqueous solution is 0.5-1.0% or less.
Preferably, the inorganic base is sodium hydroxide or potassium hydroxide.
Preferably, step B is circulated by means of a circulation pump in the middle and at the top of the reactor for 2. + -. 0.5 hours after the addition of acetone cyanohydrin has been completed.
Preferably, the cooling medium in step (1) is liquid halogen, and is used for cooling the dissolution reaction kettle.
Preferably, the bromochlorohydantoin obtained in step (2) is in the form of powder, and is prepared into flaky bromochlorohydantoin after granulation and tabletting.
Preferably, the mixing tank is an enamel mixing tank, the reactor is a tower reactor, and the synthesis reaction kettle and the dissolution reaction kettle are enamel reaction kettles.
Preferably, the ammonia gas displaced in step S2 is absorbed by spraying water to prepare ammonia water, and the ammonia water is used for synthesizing 5, 5-dimethylhydantoin in step S1.
Adopt the produced beneficial effect of above-mentioned technical scheme to lie in: compared with the prior art, the method utilizes water, ammonia gas and carbon dioxide to react to generate ammonium bicarbonate, then uses acetone cyanohydrin and ammonium bicarbonate as raw materials to carry out synthesis reaction to obtain 5, 5-dimethylhydantoin, and introduces inert gas into 5, 5-dimethylhydantoin aqueous solution to remove the dissolved surplus ammonia; adding 5, 5-dimethylhydantoin and inorganic base into a dissolution reaction kettle for cooling, introducing bromine for bromination reaction after the temperature reaches the requirement, introducing chlorine for chlorination reaction, placing the reaction material into a centrifuge for centrifugal drying after the reaction is finished, and drying to prepare powdery bromochlorohydantoin. According to the invention, after the dissolved ammonia in the 5, 5-dimethylhydantoin aqueous solution is removed by the inert gas, the bromochlorohydantoin is synthesized, so that the production steps are reduced, the production cost and the production potential safety hazard are reduced, and meanwhile, the continuous production from the synthesis of the dimethylhydantoin to the bromochlorohydantoin is realized by linking all the working procedures by adopting a conveying pipeline.
Detailed Description
The following is a clear and complete description of the technical solutions in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1: a continuous production method of bromochlorohydantoin comprises the following steps:
1. adding acetone cyanohydrin and water into an enamel mixing tank respectively for mixing to obtain a mixed solution of acetone cyanohydrin and water;
2. introducing steam into a jacket of the tower reactor, introducing carbon dioxide and ammonia gas from the bottom of the tower reactor, introducing a mixed solution of acetone cyanohydrin and water from the top of the reactor, highly dispersing a gas phase in a liquid phase for reaction, circulating the acetone cyanohydrin in the middle and the top of the tower by using a circulating pump for 2 hours after the acetone cyanohydrin is quantitatively added, and flowing the materials into a synthetic enamel reaction kettle from the bottom of the tower. Wherein the molar ratio of acetone cyanohydrin, carbon dioxide and ammonia gas is 1: 2.5: 1.2.
introducing steam into the jacket of the synthetic enamel reaction kettle, controlling the reaction temperature of the materials at 60 ℃ for reacting for 2.5 hours, and preparing the 5, 5-dimethyl hydantoin aqueous solution after the reaction is finished.
3. Introducing inert gas into the 5, 5-dimethylhydantoin aqueous solution in the synthetic enamel reaction kettle at the inert gas introduction speed of 40m, displacing ammonia in the 5, 5-dimethylhydantoin aqueous solution in the synthetic enamel reaction kettle, spraying and absorbing the ammonia with water to prepare ammonia water for use in the dimethylhydantoin synthesis, and realizing the recycling of the ammonia gas; and detecting that the ammonia content of the solution in the synthetic enamel reaction kettle is less than 0.5 percent, and finishing the ammonia removal process.
Because the 5, 5-dimethyl hydantoin aqueous solution is dissolved with surplus ammonia, if the dimethyl hydantoin aqueous solution without ammonia removal is directly used for the bromine chlorine hydantoin synthesis process, the ammonia in the dimethyl hydantoin aqueous solution can react with chlorine gas violently to produce inert gas and hydrogen chloride gas, and simultaneously, the chlorine and the hydrogen chloride react to produce a large amount of white smoke, which is very dangerous.
4. Adding a 5, 5-dimethyl hydantoin aqueous solution and a certain amount of water in a reaction kettle into a reaction kettle for dissolving enamel, introducing frozen liquid halogen into a jacket of the reaction kettle for cooling, simultaneously adding liquid alkali (sodium hydroxide) for continuously cooling, transferring the mixture of the 5, 5-dimethyl hydantoin and the sodium hydroxide into a halogenation synthesis reaction kettle after the temperature of the mixture is reduced to 25 ℃, introducing bromine and chlorine for carrying out a bromine chlorination reaction, and controlling the halogenation reaction temperature to be 30 ℃ for carrying out the bromine chlorination reaction. Wherein the molar ratio of the 5, 5-dimethyl hydantoin to the sodium hydroxide to the bromine is 1: 2.5: 1.0.
5. centrifuging and drying after the completion of the bromochlorination reaction to obtain powdery bromochlorohydantoin; then the powdery bromochlorohydantoin is granulated and tableted to prepare the flaky bromochlorohydantoin.
Example 2:
1. adding acetone cyanohydrin and water into an enamel mixing tank respectively for mixing to obtain a mixed solution of acetone cyanohydrin and water;
2. introducing steam into a jacket of the tower reactor, introducing carbon dioxide and ammonia gas from the bottom of the tower reactor, introducing a mixed solution of acetone cyanohydrin and water from the top of the reactor, highly dispersing a gas phase in a liquid phase for reaction, circulating the acetone cyanohydrin in the middle and the top of the tower by using a circulating pump for 2 hours after the acetone cyanohydrin is quantitatively added, and flowing the materials into a synthetic enamel reaction kettle from the bottom of the tower. Wherein the molar ratio of the acetone cyanohydrin, the carbon dioxide and the ammonia gas is 1:3.5: 2.0.
Introducing steam into the jacket of the synthetic enamel reaction kettle, controlling the reaction temperature of the materials at 80 ℃ for 4 hours, and preparing the 5, 5-dimethyl hydantoin aqueous solution after the reaction is finished.
3. Introducing inert gas into the 5, 5-dimethylhydantoin aqueous solution in the synthetic enamel reaction kettle at the inert gas introduction speed of 45m, displacing ammonia in the 5, 5-dimethylhydantoin aqueous solution in the synthetic enamel reaction kettle, spraying and absorbing the ammonia with water to prepare ammonia water for use in dimethylhydantoin synthesis, and realizing the recycling of the ammonia gas; and detecting that the ammonia content of the solution in the synthetic enamel reaction kettle is less than 1.0 percent, and finishing the ammonia removal process.
4. Adding a 5, 5-dimethyl hydantoin aqueous solution and a certain amount of water in a reaction kettle into a reaction kettle for dissolving enamel, introducing frozen liquid halogen into a jacket of the reaction kettle for cooling, simultaneously adding liquid alkali (sodium hydroxide) for continuously cooling, transferring the mixture of the 5, 5-dimethyl hydantoin and the sodium hydroxide into a halogenation synthesis reaction kettle after the temperature of the mixture is reduced to 20 ℃, introducing bromine and chlorine for carrying out a bromine chlorination reaction, and controlling the halogenation reaction temperature to be 25 ℃ for carrying out the bromine chlorination reaction. Wherein the molar ratio of the 5, 5-dimethyl hydantoin to the sodium hydroxide to the bromine is 1:3.5: 2.0.
5. centrifuging and drying after the completion of the bromochlorination reaction to obtain powdery bromochlorohydantoin; then the powdery bromochlorohydantoin is granulated and tableted to prepare the flaky bromochlorohydantoin.
And the continuous production from the synthesis of dimethyl hydantoin to the synthesis of bromochlorohydantoin is realized by linking the procedures in the steps through a conveying pipeline.
In conclusion, the invention utilizes water, ammonia gas and carbon dioxide to react to generate ammonium bicarbonate, and then acetone cyanohydrin and ammonium bicarbonate are used as raw materials to carry out synthetic reaction to obtain 5, 5-dimethylhydantoin; introducing inert gas into the 5, 5-dimethylhydantoin aqueous solution to remove dissolved surplus ammonia, thereby avoiding potential safety hazard caused by the reaction of the surplus ammonia in the 5, 5-dimethylhydantoin and chlorine in the subsequent step to produce inert gas and hydrogen chloride gas; adding 5, 5-dimethylhydantoin and sodium hydroxide into a dissolution reaction kettle, introducing bromine for bromination reaction after the temperature is reduced to the requirement, and then introducing chlorine for chlorination reaction to generate bromochlorohydantoin; and after the reaction is finished, putting the reaction material into a centrifuge for centrifugal drying, drying to prepare powdery bromochlorohydantoin, and then granulating and tabletting to prepare the flaky bromochlorohydantoin. The method for synthesizing the bromochlorohydantoin can simplify the production process, reduce the production steps, reduce the production cost and potential safety hazards, and simultaneously realize the continuous production from the synthesis of the dimethylhydantoin to the bromochlorohydantoin by linking all the procedures by adopting a conveying pipeline.
In the description above, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and thus the present invention is not limited to the specific embodiments disclosed above.
Claims (5)
1. A continuous production method of bromochlorohydantoin is characterized by comprising the following steps:
s1: preparation of 5, 5-dimethylhydantoin:
A. acetone cyanohydrin and water were mixed in a ratio of 1: adding the mixture into a mixing tank at a ratio of 1-1:1.5 respectively for mixing to obtain a mixed solution of acetone cyanohydrin and water;
B. introducing steam into a reactor jacket, introducing carbon dioxide and ammonia gas from the bottom of the reactor, and introducing a mixed solution of acetone cyanohydrin and water from the top of the reactor to highly disperse a gas phase in a liquid phase for reaction; the molar ratio of acetone cyanohydrin, carbon dioxide and ammonia gas is 1: 2.5: 1.2-1: 3.5: 2.0;
b, after the acetone cyanohydrin is added, circulating the mixture in the middle and the top of the reactor for 2 +/-0.5 hours by a circulating pump;
C. the mixed material flows into a synthesis reaction kettle from the bottom of the reactor; introducing steam into a jacket of a synthesis reaction kettle, controlling the reaction temperature of the materials at 60-80 ℃, and the reaction time at 2.5-4 hours to prepare a 5, 5-dimethylhydantoin aqueous solution after the reaction is finished;
s2: ammonia removal from 5, 5-dimethylhydantoin aqueous solution:
after the step S1 is finished, replacing free ammonia in the obtained 5, 5-dimethyl hydantoin aqueous solution by inert gas to obtain the 5, 5-dimethyl hydantoin aqueous solution with the ammonia content of below 0.5-1.0%;
carrying out dry top-bottom-45 m high-speed transformation by introducing inert gas into the 5, 5-dimethylhydantoin aqueous solution in the synthesis reaction kettle at the inert gas introduction speed of 40m, and displacing ammonia in the 5, 5-dimethylhydantoin aqueous solution in the synthesis reaction kettle; detecting that the ammonia content in the 5, 5-dimethyl hydantoin aqueous solution in the synthesis reaction kettle is less than 0.5-1.0 percent, and finishing the ammonia removal process;
the ammonia gas displaced in the step S2 is sprayed and absorbed by water to prepare ammonia water which is applied to the step S1 to synthesize 5, 5-dimethylhydantoin;
s3: preparing bromine chlorine hydantoin:
(1) adding a 5, 5-dimethylhydantoin aqueous solution and water in a synthesis reaction kettle into a dissolution reaction kettle, introducing a cooling medium into a jacket of the dissolution reaction kettle for cooling, simultaneously adding liquid inorganic base into the dissolution reaction kettle for continuously cooling, and transferring a mixture of dimethylhydantoin and inorganic base into a halogenation synthesis reaction kettle after the temperature of the mixture is reduced to 20-25 ℃;
(2) introducing bromine into a halogenation synthesis reaction kettle for bromination reaction, then introducing chlorine gas for chlorination reaction, and controlling the reaction temperature at 25-30 ℃ for reaction;
the molar ratio of the 5, 5-dimethylhydantoin to the inorganic base to the bromine is 1: 2.5-3.5: 1.0-2.0;
(3) centrifuging and drying after the completion of the bromochlorination reaction to obtain bromochlorohydantoin;
and the continuous production from the synthesis of dimethyl hydantoin to the synthesis of bromochlorohydantoin is realized by linking the procedures in the steps through a conveying pipeline.
2. The continuous production method of bromochlorohydantoin according to claim 1, wherein: the inorganic alkali is sodium hydroxide or potassium hydroxide.
3. The continuous production method of bromochlorohydantoin according to claim 1, wherein: the cooling medium in the step (1) is liquid halogen and is used for cooling the dissolution reaction kettle.
4. The continuous production method of bromochlorohydantoin according to claim 1, wherein: and (4) granulating and tabletting the bromochlorohydantoin obtained in the step (3) to obtain flaky bromochlorohydantoin.
5. The continuous production method of bromochlorohydantoin according to claim 1, wherein: the mixing tank is an enamel mixing tank, the reactor is a tower reactor, and the synthesis reaction kettle and the dissolution reaction kettle are enamel reaction kettles.
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| US7999118B2 (en) * | 2000-01-18 | 2011-08-16 | Albemarle Corporation | Process for producing N-halogenated hydantoins |
| CN202766443U (en) * | 2012-06-18 | 2013-03-06 | 江苏胜意药业有限公司 | Novel Bromo-3-chloro-5,5-dimethylhydantoin (BCDMH) powder producing device |
| CN103333115B (en) * | 2013-07-15 | 2015-01-21 | 河北鑫淘源环保科技有限公司 | Production method of bromo-3-chloro-5,5-dimethylhydantoin (BCDMH) serving as chemical intermediate |
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