CN105646271A

CN105646271A - Method for recovering N,N-dimethyl acetamide from waste liquid generated in cefuroxime acid production through extraction

Info

Publication number: CN105646271A
Application number: CN201510892628.1A
Authority: CN
Inventors: 王承学; 王海军
Original assignee: Changchun University of Technology
Current assignee: Changchun University of Technology
Priority date: 2015-12-08
Filing date: 2015-12-08
Publication date: 2016-06-08

Abstract

The invention relates to a method for recovering N,N-dimethyl acetamide (DMAC) from waste liquid generated in cefuroxime acid production through extraction. The method comprises the following steps: adding alkali (sodium carbonate) into wastewater generated in cefuroxime acid production, wherein DMAC accounts for 17 to 18 wt% of wastewater; allowing the system to stand still, filtering to remove impurities, adding an extractant according to a certain ratio of extractant to alkali containing wastewater, allowing the system to stand still to carry out layering so as to obtain an organic phase, and subjecting the organic phase to rotary evaporation to remove solvents with a low boiling point so as to obtain pure DMAC. The isoelectric point of DMAC is slightly alkaline, so N,N-dimethyl acetamide is recovered by an extractant under an alkaline condition to improve the recovery rate of N,N-dimethyl acetamide. The method can be carried out under a normal pressure at a normal temperature, has the advantages of low energy consumption, simple operation, short time, easy realization, little using amount of alkali, and high recovery rate, and can well process medicinal wastewater.

Description

A kind of method that reclaims DMA in cefuroxime acid production waste liquid that extracts

Technical field

The invention belongs to extraction and separation technology field, be specifically related to a kind of from cefuroxime acid producing waste water extract and separate reclaim the process of DMAC.

Background technology

DMA (DMAC), is a kind of colourless transparent liquid, can mix with organic solvents such as water, alcohol, ethers, and be a kind of polar solvent. In organic synthesis, dimethylacetylamide is fabulous catalyst, can make the reactions such as cyclisation, halogenation, cyaniding, alkylation and dehydrogenation accelerate, and can improve primary product yield. Because it has, favorable solubility, heat endurance are high, the many merits such as facile hydrolysis and being used widely industrial not: (1) prepares pharmaceutical intermediate: dimethylacetylamide is important medical material, is widely used in the production of Amoxicillin, cephalo-type medicine. Dimethylacetylamide is as solvent or co-catalyst, compared with conventional solvent, to product quality and the yield effect of being improved. (2) synthesis of polymer material: in material compound probability, DMAC is for the production of Kapton, soluble polyimide, polyimides one perfluoroethylene-propylene laminated film, polyimides (aluminium) film, soluble polyimide molding powder YS-20 etc. (3) catalyst and reaction dissolvent: dimethylacetylamide can be used as catalyst, electroanalysis solvent, paint scavenger and multiple crystalline solvent adduct and the complex compound of reaction. DMAC is also used as the solvent of synthetic fibers (acrylonitrile) and polyurethane spinning and synthesizing polyamides resin, also for the extractive distillation solvent from C8 cut separating phenylethylene, and is widely used in the aspects such as macromolecule membrane, coating and medicine. In medicine production, especially, in cephalo-type drug production process, often select DMAC to make one of base stock, and also higher to the quality requirement of DMAC. At present, high-end DMAC domestic demand still mainly depends on import. In addition, DMAC is poisonous to human body, and it absorbs through skin, and energy intense stimulus eyes, skin and mucous membrane are simultaneously also compared with difficult for biological degradation, also harmful to environment. If containing the not treated just directly discharge of waste liquid of DMAC, will inevitably cause great harm to human body and environment. Therefore, no matter be the angle from increasing economic efficiency, or from protecting the angle of personnel health, ecological environment, the DMAC reclaiming in medicine production waste liquid have certain significance.

At present, also have much about the research of extraction recovery acid amides both at home and abroad: the phenol of use alkyl (C3-C9), cyclopenta and the cyclohexyl such as the HeinzHohenschutz of Germany makees extractant and reclaims acid amides; The W.M.Langdon of the U.S. etc. use carrene to reclaim DMAC-H2O-KOAc system as extractant; The forests and streams of Tsing-Hua University etc. utilize chloroform do extractant reclaim DMAC in waste water etc. [forests and streams, Zhu Shenlin, Dai Youyuan. solvent extraction taking back and process is containing the research [J] of DMAC waste water. water technology, 2002,28 (4): 196-197]. But there is the shortcomings such as the rate of recovery is low, cost is high, equipment is complicated, energy consumption is large, complicated operation in these methods.

Summary of the invention

Goal of the invention: it is low that the present invention aims to provide a kind of energy consumption, easy operating, DMAC chemical separating method in the high Recycling of waste liquid of the rate of recovery. The present invention adopts extraction at normal temperatures and pressures, under alkali condition, extract DMAC in Recycling of waste liquid, the alkali number that extraction process needs is few, recovery of extraction is high, DMAC in extraction Recycling of waste liquid that can be simple and quick, greatly change complicated operation in existing isolation technics, energy consumption is large, the rate of recovery is low, the present situation of high in cost of production problem.

Technical scheme: in order to solve the above-mentioned technical problem of mentioning, the invention provides a kind of method that extract and separate recovery cefuroxime acid is produced DMAC in waste liquid, add alkali and extractant in waste liquid; Alkali is sodium carbonate; Extractant is the one of chloroform, carrene, benzinum, and wherein extractant and alkali waste volume ratio are 1:1 ~ 2:1.

Wherein, in above-mentioned cefuroxime acid production waste liquid, the mass content of DMAC is 17 ~ 18%.

Wherein, the mode of operation that above-mentioned alkaline extraction is taked is intermittently.

Wherein, to produce the sodium carbonate mass content that adds in waste liquid be waste liquid 2 ~ 5% for above-mentioned cefuroxime acid.

The invention process method: the waste liquid sample that measures certain volume, add 2 ~ 5% sodium carbonate of waste liquid quality to carry out basic treatment, regulate the pH value to 10 of waste liquid, leave standstill and filter out impurity, and then according to alkali waste and extractant volume ratio, add wherein a certain amount of extractant, sealing bottleneck, be placed in thermostat, at 35 DEG C, stir 60min, extractant is fully mixed with alkaline waste liquor, mixed liquor is poured in separatory funnel, treat that stratification then, to sampling respectively mutually up and down, taking n-butanol as internal standard compound, ethanol is made solvent, with gas chromatography determination analysis up and down mutually in the content of DMAC, get its organic phase and can obtain purer DMAC by steaming low boiling point solvent.

Beneficial effect: extraction efficiency is high, alkali consumption is few, selectively strong, and separating technology is simple, and the time is short, and cost is low, economically feasible. Neutralized on the one hand the excessive acid of waste liquid by alkaline extraction, regulate the pH value of waste liquid, make a part of contamination precipitation, cross and filter out, reduce on the other hand the solubility of DMAC in waste liquid, it is more easily extracted in organic phase, has greatly improved distribution coefficient and the recovery of extraction of solute DMAC.

Detailed description of the invention

Below in conjunction with example, the present invention will be further described, it should be noted that, embodiment does not form the restriction to the claimed scope of the present invention.

Embodiment 1:

The waste liquid sample that measures 20ml with graduated cylinder is to conical flask, the sodium carbonate that is slowly incorporated as sample quality mark 2% carries out basic treatment, observe its pH value change with acidometer while stirring, regulate the pH value to 10 of waste liquid, leave standstill and filter out impurity, and then be 1:1 according to alkali waste and extractant volume ratio, add wherein the extractant carrene of 20ml, add magneton, sealing bottleneck, be placed in thermostat, at 35 DEG C, stir 60min, extractant is fully mixed with alkaline waste liquor, mixed liquor is poured in separatory funnel, after stratification, to sampling respectively mutually up and down 2ml, adding 0.5ml n-butanol is internal standard compound, then use etoh solvent constant volume, with gas chromatography determination analysis up and down mutually in the content of DMAC, known after analyzing, in water, contain DMAC1.975g, DMAC2.653g in organic phase, recovery of extraction is 57.32%.

Embodiment 2:

The waste liquid sample that measures 20ml with graduated cylinder is to conical flask, slowly be incorporated as sample quality mark 5% sodium carbonate and carry out basic treatment, observe its pH value change with acidometer while stirring, regulate the pH value to 10 of waste liquid, leave standstill and filter out impurity, and then be 1:1 according to alkali waste and extractant volume ratio, add wherein the extractant carrene of 20ml, add magneton, sealing bottleneck, be placed in thermostat, at 35 DEG C, stir 60min, extractant is fully mixed with alkaline waste liquor, mixed liquor is poured in separatory funnel, after stratification, to sampling respectively mutually up and down 2ml, adding 0.5ml n-butanol is internal standard compound, then use etoh solvent constant volume, with gas chromatography determination analysis up and down mutually in the content of DMAC, known after analyzing, in water, contain DMAC1.806g, DMAC2.704g in organic phase, recovery of extraction is 59.96%.

Embodiment 3:

The waste liquid sample that measures 20ml with graduated cylinder is to conical flask, slowly be incorporated as sample quality mark 2% sodium carbonate and carry out basic treatment, observe its pH value change with acidometer while stirring, regulate the pH value to 10 of waste liquid, leave standstill and filter out impurity, and then be 2:1 according to alkali waste and extractant volume ratio, add wherein the extractant carrene of 40ml, add magneton, sealing bottleneck, be placed in thermostat, at 35 DEG C, stir 60min, extractant is fully mixed with alkaline waste liquor, mixed liquor is poured in separatory funnel, after stratification, to sampling respectively mutually up and down 2ml, adding 0.5ml n-butanol is internal standard compound, then use etoh solvent constant volume, with gas chromatography determination analysis up and down mutually in the content of DMAC, known after analyzing, in water, contain DMAC1.596g, DMAC2.873g in organic phase, recovery of extraction is 64.29%.

Embodiment 4:

The waste liquid sample that measures 20ml with graduated cylinder is to conical flask, slowly be incorporated as sample quality mark 5% sodium carbonate and carry out basic treatment, observe its pH value change with acidometer while stirring, regulate the pH value to 10 of waste liquid, leave standstill and filter out impurity, and then be 2:1 according to alkali waste and extractant volume ratio, add wherein the extractant carrene of 40ml, add magneton, sealing bottleneck, be placed in thermostat, at 35 DEG C, stir 60min, extractant is fully mixed with alkaline waste liquor, mixed liquor is poured in separatory funnel, after stratification, to sampling respectively mutually up and down 2ml, adding 0.5ml n-butanol is internal standard compound, then use etoh solvent constant volume, with gas chromatography determination analysis up and down mutually in the content of DMAC, known after analyzing, in water, contain DMAC1.432g, DMAC2.941g in organic phase, recovery of extraction is 67.25%.

Claims

1. extract a method that reclaims DMA in cefuroxime acid production waste liquid, it is characterized in that in cefuroxime acid producing waste water, adding alkali to precipitate removes impurity, then the separation that adds extractant to carry out DMAC is reclaimed; Alkali is sodium carbonate, and extractant is the one of chloroform, carrene and benzinum, and wherein extractant and alkali waste volume ratio are 1:1 ~ 2:1.

2. a kind of method that reclaims DMA in cefuroxime acid producing waste water that extracts according to claim 1, is characterized in that, in described waste liquid, the original quality content of DMAC is 17 ~ 18%.

3. a kind of method that reclaims DMA in cefuroxime acid producing waste water that extracts according to claim 1, is characterized in that, the mode that described alkaline extraction is taked is intermittently, and while adding alkali removal impurity, waste liquor PH is adjusted to 10.

4. a kind of method that reclaims DMA in cefuroxime acid producing waste water that extracts according to claim 1, is characterized in that, the sodium carbonate adding in described waste liquid is 2 ~ 5% of waste liquid mass content.

5. N in cefuroxime acid producing waste water is reclaimed in a kind of extraction according to claim 1, the method of N-dimethylacetylamide, it is characterized in that, described waste liquid, after extraction is processed, leaves standstill and treats its layering, respectively to sampling mutually up and down, taking n-butanol as internal standard compound, ethanol is made solvent, with gas chromatography determination analysis up and down mutually in the content of DMAC, calculate the recovery of extraction of DMAC.