Treatment process of triazine ring sodium salt cyclization mother liquor

Abstract

The invention belongs to the technical field of wastewater treatment, and particularly relates to a treatment process of triazine ring sodium salt cyclization mother liquor. Comprising the following steps: (1) feeding mother liquor into an alcohol separation tower, recovering methanol by normal-pressure distillation, and extracting a first base solution from the tower bottom; (2) transferring the first base solution into an intermittent evaporation kettle for vaporization, enabling a vapor phase to enter an intermittent rectifying tower for separation and recovery of ethanol, and keeping a second base solution in the kettle; (3) feeding the second base solution into a falling film evaporator to evaporate, separating a vapor phase, feeding the vapor phase into a DMF rectifying tower to recover DMF under reduced pressure, concentrating a concentrated liquid phase through a scraper evaporator, and feeding residual liquid into a residual liquid kettle; and (4) cooling the residual liquid, adding dichloromethane for extraction, and carrying out centrifugal separation and vacuum drying to obtain a sodium acetate solid. According to the treatment process, the problem that the DMF in the triazine ring sodium salt cyclization mother liquor is difficult to recover is solved; and meanwhile, the generation amount of hazardous wastes is effectively reduced, the environment-friendly treatment cost is reduced, and good economic benefits and environment-friendly benefits are achieved.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to the treatment process of mother liquor from the cyclization of sodium triazine cyclohexane. Background Technology

[0002] The triazine ring is a key intermediate in the synthesis of ceftriaxone sodium. It reacts with 7-ACA to synthesize 7-ACT, which is then further reacted with AE-active ester to synthesize ceftriaxone sodium. Ceftriaxone sodium, also known as ceftriazine, is a third-generation cephalosporin antibiotic and the first semi-synthetic broad-spectrum, long-acting cephalosporin. With its broad antibacterial spectrum, definite efficacy, and vast market potential, this product has become a dominant and important product in the antibiotic market.

[0003] The production of cephalosporin drugs relies on high-quality cephalosporin pharmaceutical intermediates. Triazine rings, as a core intermediate in the synthesis of ceftriaxone sodium, require optimized production technology and improved product quality, which are key drivers for the development of the ceftriaxone sodium industry. However, the current industry practices for handling the mother liquor from the sodium triazine ring cyclization process have significant shortcomings: after recovering methanol and ethanol, the industry generally does not recover DMF, directly disposing of the remaining liquid as hazardous waste. This treatment method not only wastes DMF, a high-value solvent, but also exposes companies to the dual challenges of high hazardous waste treatment costs and significant environmental pressure. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a treatment process for the mother liquor of triazine sodium cyclization, which solves the problem of the difficulty in recovering DMF from the mother liquor of triazine sodium cyclization; at the same time, it effectively reduces the amount of hazardous waste generated and lowers the cost of environmental treatment, thus achieving both good economic and environmental benefits.

[0005] The technical solution adopted in this invention is as follows: The treatment process for the mother liquor from the triazine sodium salt cyclization includes the following steps: (1) The mother liquor of sodium triazine ring cyclization is sent to the alcohol separation tower and treated by atmospheric distillation to separate and recover methanol. The bottom material of the alcohol separation tower is taken out as the first bottom liquid. (2) The first bottom liquid obtained in step (1) is sent to the intermittent evaporator. After being heated and vaporized in the intermittent evaporator, the vapor phase component enters the intermittent distillation column for gas-liquid mass transfer separation. The separation operation is completed by the intermittent distillation process, and ethanol is recovered. The remaining material in the intermittent evaporator is taken out as the second bottom liquid. (3) The second bottom liquid obtained in step (2) is sent to a falling film evaporator for evaporation. The vapor phase material after evaporation is separated by a gas-liquid separator and sent to a DMF distillation column. DMF is recovered by vacuum distillation. The liquid phase material after concentration in the falling film evaporator is sent to a scraped evaporator for further evaporation and concentration. The vapor phase after evaporation in the scraped evaporator is sent to a gas-liquid separator, and the residual liquid is sent to a residual liquid tank. (4) After cooling the residual liquid in the residual liquid vessel, dichloromethane is added for extraction. The extracted material is then centrifuged and vacuum dried to obtain sodium acetate solid.

[0006] The mother liquor of the triazine sodium salt cyclization comprises, by mass fraction: 65%~68% methanol, 5%~8% ethanol, 10%~13% DMF, 3%~6% diethyl oxalate, and 9%~12% sodium salt (mainly sodium acetate, containing a small amount of triazine sodium salt).

[0007] In step (1), the bottom operating temperature of the alcohol separation column is 96~98℃, the top operating temperature is 65~66℃, and the top operating pressure is 105~120kPa.

[0008] In step (2), the operating temperature of the batch evaporator is 120~125℃; the operating temperature of the top of the batch distillation column is 79~80℃, and the operating pressure at the top of the column is 105~120kPa.

[0009] In step (3), the operating temperature of the falling film evaporator is 64~66℃.

[0010] In step (3), the bottom operating temperature of the DMF distillation column is 102~105℃, the top operating temperature is 53~55℃, and the top operating pressure is -0.08MPa~-0.09MPa.

[0011] In step (3), the operating temperature of the scraped evaporator is 79~81℃.

[0012] In step (4), the temperature of the residual liquid after cooling is 20~25℃.

[0013] In step (4), the amount of dichloromethane used is 2.9 to 4.3 times the amount of residual liquid.

[0014] In step (4), the vacuum drying temperature is 33~35℃ and the pressure is -0.08MPa~-0.1MPa.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention successfully solves the industry pain point of difficult DMF recovery from the mother liquor of triazine sodium salt cyclization. Through a combination of "falling film evaporation + vacuum distillation", DMF is efficiently purified and recovered. The recovered DMF can be directly recycled as a solvent for subsequent triazine sodium salt cyclization reactions, which reduces the purchase cost of new solvents and avoids resource waste, significantly reducing the overall production cost of the product. At the same time, solvents such as methanol and ethanol are recovered simultaneously in the process, further improving resource utilization and economic benefits. (2) This invention uses a multi-stage separation and purification process to convert sodium acetate in the cyclization mother liquor into a relatively pure solid product. This dried sodium acetate can be disposed of as general solid waste in compliance with regulations, rather than being treated as hazardous waste. This improvement significantly reduces the amount of hazardous waste generated by enterprises and lowers the high costs of hazardous waste disposal; (3) In view of the component characteristics of the mother liquor of sodium triazine ring cyclization, the present invention designed a graded separation route of "atmospheric distillation-batch distillation-reduced pressure distillation". The process links are smoothly connected, the operating parameters are controllable, and it can be flexibly adapted to the processing needs of different batches, ensuring the stability and continuity of production operation and facilitating industrial promotion and application. (4) No harmful additives are introduced in the processing technology described in this invention. The separation process is green and environmentally friendly, which not only ensures product quality but also increases the added value of recycled resources, thus achieving a balance between economic and environmental benefits. Detailed Implementation

[0016] The present invention will be further described below with reference to the embodiments, but these embodiments do not limit the implementation of the present invention.

[0017] Unless otherwise specified, the raw materials used in the examples and comparative examples are all commercially available materials, and the process methods used in the examples and comparative examples are all conventional methods in the art.

[0018] The following is a description of some of the raw materials used in the examples and comparative examples: The mother liquor of triazine sodium salt cyclization, by mass fraction, includes: 66% methanol, 7% ethanol, 12% DMF, 5% diethyl oxalate and 10% sodium salt (mainly sodium acetate, containing a small amount of triazine sodium salt).

[0019] Example 1 The treatment process for the mother liquor from the triazine sodium salt cyclization includes the following steps: (1) 3000 kg of triazine sodium salt cyclization mother liquor was fed into an alcohol separation tower and treated by atmospheric distillation. The operating temperature at the bottom of the alcohol separation tower was controlled at 96℃, the operating temperature at the top of the tower was controlled at 65℃, and the operating pressure at the top of the tower was controlled at 120 kPa. 1975 kg of methanol (purity 94%) was separated and recovered. The bottom material of the alcohol separation tower was collected as the first bottom liquid. (2) The first bottom liquid obtained in step (1) is sent into the batch evaporator. The operating temperature of the batch evaporator is controlled at 120°C. After being heated and vaporized in the batch evaporator, the vapor phase component enters the batch distillation column for gas-liquid mass transfer separation. The separation operation is completed by batch distillation process. The operating temperature of the top of the batch distillation column is controlled at 79°C and the operating pressure at the top of the column is controlled at 105 kPa. 195 kg of ethanol (purity 97%) is recovered. The remaining material in the batch evaporator is taken out as the second bottom liquid. (3) The second bottom liquid obtained in step (2) is sent to a falling film evaporator for evaporation treatment, and the operating temperature of the falling film evaporator is controlled at 64℃; the vapor phase material after being separated by a gas-liquid separator is sent to a DMF distillation column, and 345 kg of DMF (purity 99.5%) is recovered by vacuum distillation process. The operating temperature of the bottom of the DMF distillation column is controlled at 102℃, the operating temperature of the top of the column is controlled at 53℃, and the operating pressure of the top of the column is controlled at -0.08MPa; the liquid phase material after being concentrated by the falling film evaporator is sent to a scraped evaporator, and the operating temperature of the scraped evaporator is controlled at 79℃ for further evaporation and concentration. The vapor phase distilled by the scraped evaporator is sent to a gas-liquid separator, and the residual liquid is sent to a residual liquid tank. (4) After cooling the residual liquid in the residual liquid vessel to 20°C, dichloromethane was added to extract diethyl oxalate. The amount of dichloromethane used was 4.3 times the amount of residual liquid. The extracted material was centrifuged and vacuum dried. The vacuum drying temperature was controlled at 33°C and the pressure was -0.08 MPa to obtain 284 kg of sodium acetate solid.

[0020] Example 2 The treatment process for the mother liquor from the triazine sodium salt cyclization includes the following steps: (1) 3100 kg of triazine sodium salt cyclization mother liquor was fed into an alcohol separation tower and treated by atmospheric distillation. The operating temperature at the bottom of the alcohol separation tower was controlled at 98℃, the operating temperature at the top of the tower was 66℃, and the operating pressure at the top of the tower was 105 kPa. 1982 kg of methanol (purity 97%) was separated and recovered. The bottom material of the alcohol separation tower was collected as the first bottom liquid. (2) The first bottom liquid obtained in step (1) is sent into the batch evaporator. The operating temperature of the batch evaporator is controlled at 125°C. After being heated and vaporized in the batch evaporator, the vapor phase component enters the batch distillation column for gas-liquid mass transfer separation. The separation operation is completed by batch distillation process. The operating temperature of the top of the batch distillation column is controlled at 80°C and the operating pressure at the top of the column is controlled at 110 kPa. 199 kg of ethanol (purity 95%) is recovered. The remaining material in the batch evaporator is taken out as the second bottom liquid. (3) The second bottom liquid obtained in step (2) is sent to a falling film evaporator for evaporation treatment, and the operating temperature of the falling film evaporator is controlled at 66℃; the vapor phase material after being separated by a gas-liquid separator is sent to a DMF distillation column, and 358 kg of DMF (purity 99.0%) is recovered by vacuum distillation process. The operating temperature of the bottom of the DMF distillation column is controlled at 105℃, the operating temperature of the top of the column is controlled at 55℃, and the operating pressure of the top of the column is controlled at -0.09MPa; the liquid phase material after being concentrated by the falling film evaporator is sent to a scraped evaporator, and the operating temperature of the scraped evaporator is controlled at 81℃ for further evaporation and concentration. The vapor phase distilled by the scraped evaporator is sent to a gas-liquid separator, and the residual liquid is sent to a residual liquid tank. (4) After cooling the residual liquid in the residual liquid vessel to 25°C, dichloromethane was added to extract diethyl oxalate. The amount of dichloromethane used was 2.9 times the amount of residual liquid. The extracted material was centrifuged and vacuum dried. The vacuum drying temperature was controlled at 35°C and the pressure was -0.09 MPa to obtain 293 kg of sodium acetate solid.

[0021] Example 3 The treatment process for the mother liquor from the triazine sodium salt cyclization includes the following steps: (1) 3050 kg of triazine sodium salt cyclization mother liquor was fed into an alcohol separation tower and treated by atmospheric distillation. The operating temperature at the bottom of the alcohol separation tower was controlled at 97℃, the operating temperature at the top of the tower was controlled at 65.5℃, and the operating pressure at the top of the tower was controlled at 115 kPa. 1978 kg of methanol (purity 95%) was separated and recovered. The bottom material of the alcohol separation tower was collected as the first bottom liquid. (2) The first bottom liquid obtained in step (1) is sent to the batch evaporator. The operating temperature of the batch evaporator is controlled at 123°C. After being heated and vaporized in the batch evaporator, the vapor phase component enters the batch distillation column for gas-liquid mass transfer separation. The separation operation is completed by batch distillation process. The operating temperature of the top of the batch distillation column is controlled at 79.5°C and the operating pressure at the top of the column is controlled at 120 kPa. 197 kg of ethanol (purity 96%) is recovered. The remaining material in the batch evaporator is taken out as the second bottom liquid. (3) The second bottom liquid obtained in step (2) is sent to a falling film evaporator for evaporation treatment, and the operating temperature of the falling film evaporator is controlled at 65℃; the vapor phase material after being separated by a gas-liquid separator is sent to a DMF distillation column, and 351 kg of DMF (purity 99.3%) is recovered by vacuum distillation process. The operating temperature of the bottom of the DMF distillation column is controlled at 103℃, the operating temperature of the top of the column is controlled at 54℃, and the operating pressure of the top of the column is controlled at -0.085 MPa; the liquid phase material after being concentrated by the falling film evaporator is sent to a scraped evaporator, and the operating temperature of the scraped evaporator is controlled at 80℃ for further evaporation and concentration. The vapor phase distilled by the scraped evaporator is sent to a gas-liquid separator, and the residual liquid is sent to a residual liquid tank. (4) After cooling the residual liquid in the residual liquid vessel to 23°C, dichloromethane was added to extract diethyl oxalate. The amount of dichloromethane used was 3.6 times the amount of residual liquid. The extracted material was centrifuged and vacuum dried. The vacuum drying temperature was controlled at 34°C and the pressure was -0.085MPa to obtain 289kg of sodium acetate solid.

Claims

1. A process for treating the mother liquor from the cyclization of sodium triazine cyclohexane, characterized in that, Includes the following steps: (1) The mother liquor of sodium triazine ring cyclization is sent to the alcohol separation tower and treated by atmospheric distillation to separate and recover methanol. The bottom material of the alcohol separation tower is taken out as the first bottom liquid. (2) The first bottom liquid obtained in step (1) is sent to the intermittent evaporator. After being heated and vaporized in the intermittent evaporator, the vapor phase component enters the intermittent distillation column for gas-liquid mass transfer separation. The separation operation is completed by the intermittent distillation process, and ethanol is recovered. The remaining material in the intermittent evaporator is taken out as the second bottom liquid. (3) The second bottom liquid obtained in step (2) is sent to a falling film evaporator for evaporation. The vapor phase material after evaporation is separated by a gas-liquid separator and sent to a DMF distillation column. DMF is recovered by vacuum distillation. The liquid phase material after concentration in the falling film evaporator is sent to a scraped evaporator for further evaporation and concentration. The vapor phase after evaporation in the scraped evaporator is sent to a gas-liquid separator, and the residual liquid is sent to a residual liquid tank. (4) After cooling the residual liquid in the residual liquid vessel, dichloromethane is added for extraction. The extracted material is then centrifuged and vacuum dried to obtain sodium acetate solid.

2. The treatment process for the mother liquor of triazine cyclization sodium salt according to claim 1, characterized in that, The mother liquor for the cyclization of the triazine sodium salt comprises, by mass fraction: 65%~68% methanol, 5%~8% ethanol, 10%~13% DMF, 3%~6% diethyl oxalate, and 9%~12% sodium salt.

3. The treatment process for the mother liquor from the triazine cyclization of sodium salt according to claim 1, characterized in that, In step (1), the bottom operating temperature of the alcohol separation column is 96~98℃, the top operating temperature is 65~66℃, and the top operating pressure is 105~120kPa.

4. The treatment process for the mother liquor from the triazine cyclization of sodium salt according to claim 1, characterized in that, In step (2), the operating temperature of the batch evaporator is 120~125℃; the operating temperature of the top of the batch distillation column is 79~80℃, and the operating pressure at the top of the column is 105~120kPa.

5. The treatment process for the mother liquor from the triazine cyclization of sodium salt according to claim 1, characterized in that, In step (3), the operating temperature of the falling film evaporator is 64~66℃.

6. The treatment process for the mother liquor of triazine cyclization sodium salt according to claim 1, characterized in that, In step (3), the bottom operating temperature of the DMF distillation column is 102~105℃, the top operating temperature is 53~55℃, and the top operating pressure is -0.08MPa~-0.09MPa.

7. The treatment process for the mother liquor from the triazine sodium cyclization according to claim 1, characterized in that, In step (3), the operating temperature of the scraped evaporator is 79~81℃.

8. The treatment process for the mother liquor from the triazine cyclization of sodium salt according to claim 1, characterized in that, In step (4), the temperature of the residual liquid after cooling is 20~25℃.

9. The treatment process for the mother liquor from the triazine cyclization of sodium salt according to claim 1, characterized in that, In step (4), the amount of dichloromethane used is 2.9 to 4.3 times the amount of residual liquid.

10. The treatment process for the mother liquor of triazine cyclization sodium salt according to claim 1, characterized in that, In step (4), the vacuum drying temperature is 33~35℃ and the pressure is -0.08MPa~-0.1MPa.