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CN-122010791-A - Method for producing taurine by utilizing improved ethylene oxide method

CN122010791ACN 122010791 ACN122010791 ACN 122010791ACN-122010791-A

Abstract

The invention discloses a method for producing taurine by using an improved ethylene oxide method, belonging to the technical field of fine chemical synthesis. In the sulfonation reaction step, ethylene oxide and sulfite are reacted in the presence of a phase transfer catalyst and a free radical inhibitor, preferably copper sulfate and/or an additive having dual functions of free radical inhibition and ammonolysis catalysis are adopted. And then, the obtained isethionate solution is directly subjected to ammonolysis reaction with ammonia water in the presence of the additive (serving as a Lewis acid catalyst), and finally, the high-purity taurine product is obtained through acidification, membrane filtration, crystallization and drying. The invention effectively inhibits side reaction in the sulfonation stage through the innovative design of one-dose double effect, obviously improves the efficiency of ammonolysis reaction, ensures that the whole process is carried out under milder conditions, ensures that the total yield of the final taurine product is high (more than 87 percent), ensures that the purity is stable to more than 99.5 percent, has less three-waste discharge and has obvious industrial application value.

Inventors

  • ZHU HENGBING
  • CHEN WENYU
  • YANG YAYONG
  • XIONG SHUANG
  • HUA ZHENGGEN
  • ZHENG HONGQIANG
  • LIN KE
  • LIN HUI

Assignees

  • 厦门圣元药业有限公司

Dates

Publication Date
20260512
Application Date
20260131

Claims (10)

  1. 1. A process for producing taurine by a modified ethylene oxide process comprising the steps of: (1) Sulfonation reaction, namely, in the presence of a phase transfer catalyst and a free radical inhibitor, ethylene oxide reacts with sulfite in an aqueous solution to generate isethionate; (2) Ammonolysis reaction, namely ammonolysis is carried out on the reaction liquid obtained in the step (1) and ammonia to generate taurine salt; (3) Acidifying and refining, namely acidifying the taurine salt solution obtained in the step (2), and then filtering, concentrating, crystallizing and drying the taurine salt solution through a membrane to obtain a taurine product.
  2. 2. The method according to claim 1, wherein the phase transfer catalyst is one or more selected from quaternary ammonium salt, quaternary phosphonium salt and polyethylene glycol, and the addition amount of the phase transfer catalyst is 0.5% -5% of the mass of the sulfite.
  3. 3. The method according to claim 2, wherein the quaternary ammonium salt is tetrabutylammonium bromide or cetyltrimethylammonium bromide and the polyethylene glycol is PEG-400 or PEG-600.
  4. 4. The method according to claim 1, wherein the free radical inhibitor is one or more of copper sulfate, zinc sulfate or hydrate thereof, and the addition amount of the free radical inhibitor is 1% -3% of the mass of the sulfite; Preferably, the radical inhibitor is a combination of copper sulfate and zinc sulfate, wherein the addition amount of copper sulfate is 1.2% of the mass of sulfite, and the addition amount of zinc sulfate is 0.4% of the mass of sulfite.
  5. 5. The method according to claim 1, wherein the sulfonation reaction is carried out at a reaction temperature of 40-80 ℃, a reaction pressure of 0.1-0.5 MPa, and a reaction time of 1-4 hours.
  6. 6. The method according to claim 1, wherein the molar ratio of ammonia to isethionate in the ammonolysis reaction is (5-15) 1, the reaction temperature is 120-160 ℃, the reaction pressure is 1.0-3.0 MPa, and the reaction time is 2-6 hours.
  7. 7. The method of claim 1, wherein in step (3), the acidification is to adjust the pH of the solution to 3.5-4.5 using mineral acid.
  8. 8. The method of claim 1, wherein in step (3), the membrane filtration is microfiltration or ultrafiltration.
  9. 9. The method of claim 1, wherein the sulfite is sodium bisulfite or ammonium sulfite.
  10. 10. A taurine prepared by the method of any one of claims 1-9.

Description

Method for producing taurine by utilizing improved ethylene oxide method Technical Field The invention belongs to the technical field of fine chemical synthesis, and particularly relates to a method for producing taurine by using an improved ethylene oxide method. Background Taurine, the chemical name of which is 2-aminoethanesulfonic acid, is an important sulfur-containing amino acid and has extremely wide application in the fields of medicine, functional food additives, pet feeds, cosmetics and the like. Currently, the mainstream method for industrially synthesizing taurine worldwide is the ethylene oxide method (also called ethanolamine method), which uses ethylene oxide and sodium bisulphite (or ammonium sulfite) as main raw materials, and generally comprises the following two core steps: The first step is sulfonation reaction, namely nucleophilic ring-opening addition reaction of ethylene oxide and sodium bisulphite in aqueous solution to generate intermediate sodium isethionate. However, the step has the obvious defect that the chemical property of the ethylene oxide is active, and free radical side reactions such as ring-opening polymerization and the like are very easy to occur under the reaction condition, so that polyethylene glycol sulfonate and other byproducts are generated. This not only consumes valuable raw materials, resulting in reduced yield and purity of sodium isethionate, but also increases the difficulty of subsequent separation and the burden of wastewater treatment. The second step is ammonolysis reaction, namely, the reaction of sodium isethionate and ammonia water at high temperature and high pressure to generate the target product sodium taurate. This step is the bottleneck of the overall process. Traditional non-catalytic ammonolysis reactions are extremely demanding and typically require reactions at high temperatures in excess of 150 ℃ and pressures above 3.0 MPa for up to 6 to 8 hours. This not only puts very high demands on the safety of the reaction equipment, resulting in huge energy consumption, but also easily causes side reactions such as product decomposition and coloring after long-time high-temperature treatment, and affects the quality of the final product. In addition, the whole process route also faces the problems of large discharge amount of three wastes, complex product refining process, difficulty in stably reaching the pharmaceutical grade standard and the like. To overcome these difficulties, there have been attempts to improve on a single stage, such as adding inhibitors during the sulfonation step, or adding various types of catalysts during the ammonolysis step, but these improvements are often isolated, localized. At present, a comprehensive solution capable of systematically and integrally optimizing the whole process flow, simultaneously inhibiting side reactions from the source, strengthening main reactions and simplifying operation is still lacking. Therefore, developing a taurine production method with mild reaction conditions, high selectivity, high yield, environmental protection and stable product purity becomes a technical problem to be solved urgently by those skilled in the art. The present invention has been made in this context. Disclosure of Invention The invention aims to overcome the defects of the prior art and provides an improved method for producing taurine by an ethylene oxide method. The method aims at improving the reaction rate and selectivity, reducing the reaction temperature and pressure, reducing the emission of three wastes and finally obtaining the taurine product with high yield and high purity by optimizing a reaction system, introducing a high-efficiency catalyst and improving a post-treatment process. In order to achieve the above purpose, the present invention provides the following technical solutions: a process for producing taurine by a modified ethylene oxide process comprising the steps of: (1) Sulfonation reaction, namely, in the presence of a phase transfer catalyst and a free radical inhibitor, ethylene oxide reacts with sulfite in an aqueous solution to generate isethionate; (2) Ammonolysis reaction, namely ammonolysis is carried out on the reaction liquid obtained in the step (1) and ammonia to generate taurine salt; (3) Acidifying and refining, namely acidifying the taurine salt solution obtained in the step (2), and then filtering, concentrating, crystallizing and drying the taurine salt solution through a membrane to obtain a taurine product. Further, the phase transfer catalyst is selected from one or more of quaternary ammonium salt, quaternary phosphonium salt or polyethylene glycol, and the addition amount of the phase transfer catalyst is 0.5% -5% of the mass of the sulfite. Further, the quaternary ammonium salt is tetrabutylammonium bromide or hexadecyl trimethyl ammonium bromide, and the polyethylene glycol is PEG-400 or PEG-600. Further, the free radical inhibitor is one or more of copper sulfate, z