Method for recovering and purifying ethanol-ethyl acetate-piperazine waste solvent

A technology of ethyl acetate and a purification method, which is applied in the field of waste liquid purification, can solve the problems of reduced distillation effect and efficiency, low liquid output efficiency, and high difficulty in purification, and achieves reduced waste solvent generation, stable operation, and good quality Effect

Inactive Publication Date: 2021-10-22
四川熔增环保科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

A large amount of waste solvents containing ethanol, ethyl acetate, piperazine, a small amount of water and trace pharmaceutical ingredients are produced in pharmaceutical production. Due to the high difficulty of purification, most of them are discarded and no longer used, resulting in great waste. After incineration or discharge, the environment is also harmful. It will cause great pollution. At the same time, the distillation stage in the recovery and purification process of ethanol-ethyl acetate-piperazine waste solvent will produce ethanol liquid backflow, which will reduce the effect and efficiency of distillation. In addition, after the liquid is discharged, part of the liquid will remain in the In the liquid outlet pipe, the liquid outlet efficiency is not high. Therefore, a recovery and purification method for ethanol-ethyl acetate-piperazine waste solvent is proposed

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  • Method for recovering and purifying ethanol-ethyl acetate-piperazine waste solvent
  • Method for recovering and purifying ethanol-ethyl acetate-piperazine waste solvent
  • Method for recovering and purifying ethanol-ethyl acetate-piperazine waste solvent

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Effect test

Embodiment 1

[0027] Waste solvent ethanol-ethyl acetate-piperazine recovery and purification method, the extraction steps include:

[0028] Take waste solvent containing 53% ethanol, 42% ethyl acetate, 4% piperazine, rectify, and the conditions of rectification are: rectification still bottom temperature 112°C, liquid temperature in the still 109°C, still top temperature 70~78°C , control the reflux ratio of 10:1; separate ethanol, ethyl acetate and a small amount of water; piperazine is extracted from the tower kettle, and after passing the test, it can be packed and stored with nitrogen gas to obtain anhydrous piperazine with a purity ≥ 99.5% (wt). .

[0029] The ethanol and ethyl acetate obtained by the above rectification were added to 1.45 times the volume of waste solvent water, washed with water, the upper layer obtained an organic phase composed of ethyl acetate and water, and the lower layer obtained an aqueous phase composed of ethanol and water.

[0030] The above-mentioned org...

Embodiment 2

[0033] Waste solvent ethanol-ethyl acetate-piperazine recovery and purification method, the extraction steps include:

[0034] Take the waste solvent containing 55% ethanol, 39% ethyl acetate, 5% piperazine, rectify, the conditions of rectification are: rectification still bottom temperature 112°C, liquid temperature in the still 109°C, still top temperature 70~78°C , Control the reflux ratio to 6:1; separate out ethanol, ethyl acetate and a small amount of water; extract piperazine from the tower kettle, pack it in a tank after passing the test, and store it with nitrogen gas to obtain anhydrous piperazine with a purity ≥ 99.5% (wt) .

[0035]The ethanol and ethyl acetate obtained by the above rectification were added to 1.35 times the volume of waste solvent water, washed with water, the upper layer obtained an organic phase composed of ethyl acetate and water, and the lower layer obtained an aqueous phase composed of ethanol and water.

[0036] The above-mentioned organic ...

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Abstract

The invention discloses a method for recovering and purifying an ethanol-ethyl acetate-piperazine waste solvent. The method comprises the following steps: S1, taking a waste solvent ethanol-ethyl acetate-piperazine, rectifying, separating ethanol and ethyl acetate, extracting piperazine from a tower kettle, and obtaining anhydrous piperazine in the purity greater than or equal to 99.5%(wt); S2, adding a certain amount of water into the ethanol and ethyl acetate obtained by rectification, washing with water to obtain an organic phase consisting of ethyl acetate and a small amount of water on the upper layer, and obtaining a water phase consisting of ethanol and water on the lower layer; and S3, carrying out azeotropic distillation on the organic phase obtained by water washing to obtain an azeotropic mixture of ethyl acetate and water at the tower top, and carrying out layering and liquid separation. According to the method, ethanol, ethyl acetate and piperazine are separated and water and other impurities are removed through rectification separation, extraction separation, azeotropic rectification separation and rectification coupling membrane separation and dehydration separation, so that purification, recovery and circulation of a solvent are achieved, generation of a waste solvent is reduced, and the production cost is reduced.

Description

technical field [0001] The invention relates to the technical field of waste liquid purification, in particular to a recovery and purification method for ethanol-ethyl acetate-piperazine waste solvent. Background technique [0002] With the continuous development of the pharmaceutical industry, the application of related pharmaceutical raw materials and intermediates is becoming more and more common, ethanol, ethyl acetate, and piperazine are widely used. A large amount of waste solvents containing ethanol, ethyl acetate, piperazine, a small amount of water and trace pharmaceutical ingredients are produced in pharmaceutical production. Due to the high difficulty of purification, most of them are discarded and no longer used, resulting in great waste. After incineration or discharge, the environment is also harmful. It will cause great pollution. At the same time, the distillation stage in the recovery and purification process of ethanol-ethyl acetate-piperazine waste solvent...

Claims

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Application Information

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IPC IPC(8): C07C29/80C07C31/08C07C67/54C07C69/14C07D295/023C07D295/027
CPCC07C29/80C07C67/54C07D295/023C07D295/027C07C31/08C07C69/14
Inventor 范文林纪王洋鲁加峰张怡
Owner 四川熔增环保科技有限公司
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