阅读说明：本技术 一种用于头孢合成中丙酮废液的回收方法 (method for recovering acetone waste liquid in cephalosporin synthesis ) 是由 郭海超 孔维芳 刘燕 余从立 纪祖焕 庆天 于 2019-11-28 设计创作，主要内容包括：本发明涉及一种用于头孢合成中丙酮废液的回收方法,步骤如下：将头孢合成中的丙酮废液进入粗蒸釜,调酸后采用蒸馏的方式脱除部分水与重组分；粗蒸后得到的丙酮粗蒸液进入氧化罐进行氧化；将氧化后的丙酮粗蒸液送入精馏塔进行精馏进一步除杂,精馏得到的丙酮馏液进入渗透汽化膜分离机组；经渗透汽化膜分离机组分离脱水后得到成品丙酮,料液侧溶液中的水以及少量丙酮以蒸汽形式透过渗透汽化膜得到渗透液,渗透液冷凝后返回精馏塔后再次回收其中的丙酮。本发明回收过程中,回收率高,丙酮成品质量高,工艺过程简单,安全系数高,运行能耗低。(The invention relates to a recovery method of acetone waste liquid in cephalosporin synthesis, which comprises the following steps of feeding the acetone waste liquid in cephalosporin synthesis into a rough distillation kettle, adjusting acid, removing part of water and heavy components by distillation, feeding the acetone rough distillation liquid obtained after rough distillation into an oxidation tank for oxidation, feeding the acetone rough distillation liquid obtained after oxidation into a rectifying tower for rectification, removing impurities by steps, feeding the acetone distillation liquid obtained after rectification into a pervaporation membrane separation unit, separating and dehydrating by the pervaporation membrane separation unit to obtain finished product acetone, allowing water and a small amount of acetone in a solution at a feed liquid side to permeate the pervaporation membrane in a steam form to obtain a penetrating liquid, and returning the penetrating liquid to the rectifying tower to recover the acetone in the penetrating liquid after condensation.)

1, A method for recovering acetone waste liquid in cephalosporin synthesis, which is characterized by comprising the following steps:

step 1: feeding the acetone waste liquid in the cephalosporin synthesis into a rough distillation kettle, adjusting acid, and then removing part of water and heavy components by adopting a distillation mode;

step 2, feeding the acetone crude distillate obtained after concentration in the step 1 into an oxidation tank for oxidation, and adding quantitative oxidant solution, wherein the feeding proportion of the oxidant is 0.15-2 wt% of the acetone crude distillate;

step 3, feeding the acetone crude distillate oxidized in the step 2 into a rectifying tower for rectifying for further impurity removal, and adding quantitative acid liquor into a tower kettle during rectification to control the pH value of tower kettle liquid, wherein the pH value is 1.5-7.5;

and 4, step 4: feeding the acetone distillate obtained in the step 3 after impurity removal into a pervaporation membrane separation unit; separating and dehydrating by a pervaporation membrane separator to obtain finished product acetone, allowing water and a small amount of acetone in the solution on the feed liquid side to permeate the pervaporation membrane in a steam form to obtain a penetrating fluid, condensing the penetrating fluid, returning the penetrating fluid to the rectifying tower, and recovering the acetone again.

2. The method for recovering acetone waste liquid in cephalosporin synthesis according to claim 1, characterized in that: the water content of the acetone waste liquid entering the crude distillation tower in the step 1 is 10-60 wt.%.

3. The method for recovering the acetone waste liquid in the cephalosporin synthesis according to claim 1, characterized in that quantitative acid liquid is added in the acid adjusting process in the step 1, the acid is sulfuric acid, hydrochloric acid, nitric acid or acetic acid, and the adjusted pH value is 1-6.

4. The method for recovering acetone waste liquid in cephalosporin synthesis according to claim 1, characterized in that: after the crude distillation of the crude distillation kettle in the step 1, the acetone content in the acetone crude distillation liquid is concentrated to 80-95 wt.%.

5. The method for recovering acetone waste liquid in cephalosporin synthesis according to claim 1, characterized in that: the oxidant in the step 2 is sodium percarbonate, hydrogen peroxide, potassium permanganate or potassium perchlorate, and the oxidation time is 10-60 min.

6. The method for recovering acetone waste liquid in cephalosporin synthesis according to claim 1, characterized in that: and the rectifying tower in the step 3 adopts intermittent operation.

7. The method for recovering acetone waste liquid in cephalosporin synthesis according to claim 1, characterized in that: in the 4 th step, when pervaporation separation is carried out, the gauge pressure of the feed liquid side of the pervaporation membrane is 0.1-0.4 MPa; the permeation side is connected with a vacuum system, and the absolute pressure of the permeation side is 300-2000 Pa; the membrane adopted by the pervaporation membrane separation unit is a water permeable membrane, specifically a molecular sieve membrane, an amorphous silica membrane or a PVA membrane.

8. The method for recovering acetone waste liquid in cephalosporin synthesis according to claim 1, characterized in that: the water content of the finished acetone is controlled to be 0.05-0.5 wt.%.

9. The method for recovering acetone waste liquid in cephalosporin synthesis according to claim 1, characterized in that the penetrating fluid obtained in the step 4 is condensed and then returned to the rectifying tower in the step 3, distilled into acetone containing water with fixed amount, and then sent to a permeation and vaporization membrane separation unit.

Technical Field

The invention relates to a method for recovering acetone waste liquid in cephalosporin synthesis, in particular to a method for refining the acetone waste liquid in cephalosporin synthesis by pervaporation methods, belonging to the field of pervaporation membrane application.

Background

In the actual production, most of the cephalosporins use acetone as a reaction solvent or washing liquid in or multistep reactions in the synthesis process, such as cefoperazone, cefotiam, ceftizoxime, cefodizime, cefuroxime, ceftriaxone, cefoxitin and the like, after the reaction or washing is finished, the generated acetone waste liquid needs to be separated to obtain recovered acetone with fixed quality indexes (the content is more than or equal to 99.0 or 99.5%, the water content is less than or equal to 0.05-0.5 wt%, the oxidation resistance is more than or equal to 80min, the pH is between 6-8, and the chroma is less than or equal to 5 Hazen) which is used as the reaction solvent again for circulation.

In the traditional process for recovering the cefprozil waste liquid, two-time rectification or rough distillation and rectification modes are generally adopted for recovery, the acetone recovered by the two methods can reach indexes in the aspects of acetone purity and moisture, but indexes such as oxidation resistance, pH, chromaticity, turbidity and the like can cause problems, generally, or more of the problems of pH reduction (pH is less than 6), oxidation resistance deterioration (oxidation resistance time is less than 80 min), color turning to light yellow or light green, turbidity reduction and the like can occur after the recovered acetone is kept still for 2-5 days, the root cause of the problem is that micro impurities are distilled out along with the acetone and dissolved in the acetone distillate, the indexes cannot be influenced when the acetone is distilled out, and the impurities are slowly decomposed along with the increase of the standing time, so that the indexes are deteriorated.

Disclosure of Invention

The invention aims to provide recovery methods for acetone waste liquid in cephalosporin synthesis, which have the characteristics of simple process, small equipment floor area, high safety coefficient, low energy consumption, high acetone yield, cleanness and no pollution.

The technical scheme is as follows:

method for recovering acetone waste liquid in cephalosporin synthesis, comprising the following steps:

step 1, feeding acetone waste liquid in cephalosporin synthesis into a rough distillation kettle, adjusting acid, and removing part of water and heavy components by adopting a distillation mode;

step 2, feeding the crude acetone distillate obtained in the step 1 into an oxidation tank for oxidation;

step 3, feeding the acetone crude distillate oxidized in the step 2 into a rectifying tower for rectifying and further removing impurities in the step ;

step 4, feeding the acetone distillate obtained in the step 3 after impurity removal into a pervaporation membrane separation unit; separating and dehydrating by a pervaporation membrane separator to obtain finished product acetone, allowing water and a small amount of acetone in the solution on the feed liquid side to permeate the pervaporation membrane in a steam form to obtain a penetrating fluid, condensing the penetrating fluid, returning the penetrating fluid to the rectifying tower, and recovering the acetone again.

Preferably, the water content of the acetone waste liquid entering the crude distillation tower in the step 1 is 10-60 wt.%.

Preferably, quantitative acid liquor is added in the acid adjusting process in the step 1, the acid is sulfuric acid, hydrochloric acid, nitric acid or acetic acid, and the adjusted pH value is 1-6.

Preferably, after the crude distillation in the crude distillation kettle in the step 1, the acetone content in the acetone crude distillation liquid is concentrated to 80-95 wt.%.

Preferably, in the oxidation in the step 2, quantitative oxidant solution is added, the feeding proportion of the oxidant is 0.15-2 wt% of the acetone crude distillation liquid, the oxidant is sodium percarbonate, hydrogen peroxide, potassium permanganate or potassium perchlorate, and the oxidation time is 10-60 min.

Preferably, in the step 3, the rectifying tower is operated intermittently, quantitative acid liquor is added into a tower kettle during rectification to control the pH value of tower kettle liquid, and the pH value is 1.5-7.5.

Preferably, in the 4 th step, when the pervaporation separation is performed, the gauge pressure of the feed liquid side of the pervaporation membrane is 0.1 to 0.4 MPa; the permeation side is connected with a vacuum system, and the absolute pressure of the permeation side is 300-2000 Pa; the membrane adopted by the pervaporation membrane separation unit is a water permeable membrane, specifically a molecular sieve membrane, an amorphous silica membrane or a PVA membrane.

Preferably, the water content of the finished acetone is controlled to be 0.05-0.5 wt.%.

Preferably, the penetrating fluid obtained in the step 4 is condensed and then returned to the rectifying tower in the step 3, distilled into acetone containing fixed water, and then sent to a penetrating and vaporizing membrane separation unit.

Advantageous effects

Compared with the traditional process for recovering acetone, the method has the following characteristics:

1. according to the invention, impurities in the cefprozil waste liquid are treated in a targeted manner by combining the processes of rough steaming, oxidation and rectification, so that the problems of unstable indexes such as oxidation resistance, pH, chromaticity, turbidity and the like of the recovered acetone are effectively solved, and the recovered acetone has higher and more stable quality;

2. the invention adopts the pervaporation membrane separation unit for dehydration, so that the dehydration energy consumption is low, the process is simple, and the safety coefficient is high;

3. the pervaporation membrane separation unit has high automation degree, simple and convenient operation and small occupied area of equipment;

4. the method adopts a mode of concentrating to remove impurities and then pervaporation, does not introduce a third component, and ensures the purity of the product;

5. the invention returns the penetrating fluid to the rectifying tower for recovery treatment, reduces the discharge amount of acetone and improves the recovery rate of the acetone.

Drawings

FIG. 1 is a process flow diagram of a method for recovering acetone waste liquid in cephalosporin synthesis;

wherein, 1 is a rough distillation kettle, 2 is an oxidation tank, 3 is a rectifying tower, 4 is a tower kettle, 5 is an evaporator, 6 is a pervaporation membrane separation unit, and 7 is a penetrating fluid condenser.

Detailed Description

The present invention is described in further detail by way of specific embodiments, but those skilled in the art will appreciate that the following examples are illustrative only and should not be taken as limiting the scope of the invention.