1. A recovery and purification device for waste solvent ethanol-cyclohexane-piperazine comprises: the device comprises a waste water tank, a rectification separation tower, an ethanol and cyclohexane extraction tower, an ethanol rectification tower and a dehydration tower, and is characterized in that the waste water tank is connected to the rectification separation tower, the rectification separation tower is connected to the ethanol and cyclohexane extraction tower, the ethanol rectification tower is connected to the rectification separation tower, the dehydration tower is connected to the ethanol rectification tower, a vibration flow distribution structure is installed in the ethanol and cyclohexane extraction tower, a flow distribution structure is installed in the dehydration tower, and a multi-section rectification structure is installed in the ethanol rectification tower and the rectification separation tower;

the vibrations reposition of redundant personnel structure includes: the ultrasonic vibration device comprises a plurality of ultrasonic vibration shafts, a concave driving box, a sound wave driving machine, a sound wave rotation driving disc, a plurality of convex rotating rods, a plurality of knocking spring columns, a plurality of rotation sound wave circular ring blocks, a plurality of concave circular ring blocks, a plurality of longitudinal slideways, a plurality of longitudinal sliders, a plurality of clip stoppers, a plurality of transverse slideways, a plurality of transverse sliders, a plurality of transverse spring columns, a plurality of sealant, a plurality of longitudinal spring columns and a plurality of auxiliary balls;

the ethanol and cyclohexane extraction tower is provided with a plurality of sound wave grooves, a plurality of transverse slideways are respectively and oppositely arranged in the sound wave grooves in parallel, a plurality of transverse sliders are respectively arranged on a plurality of square-shaped limiting blocks, a plurality of transverse sliders are respectively and movably inserted in the transverse slideways, a plurality of longitudinal slideways are respectively and oppositely arranged in the square-shaped limiting blocks in parallel, a plurality of longitudinal sliders are respectively arranged on two sides of a plurality of concave circular ring blocks, a plurality of longitudinal sliders are respectively and movably inserted in the longitudinal slideways, a plurality of rotary sound wave circular ring blocks are respectively and movably inserted in the concave circular ring blocks, a plurality of ultrasonic vibration shafts are respectively inserted on the rotary sound wave circular ring blocks, the concave driving box is arranged on the rectification separation tower, and the sound wave driver is arranged on the concave driving box, the sound wave rotation driving disc is arranged on the driving end of the sound wave driver, a plurality of knocking grooves are formed in the sound wave rotation driving disc, a plurality of convex rotating rods are respectively inserted into the knocking grooves through bearings, a plurality of longitudinal spring columns are respectively arranged on a plurality of clip-shaped limiting blocks, the other ends of the plurality of longitudinal spring columns are respectively connected to the plurality of concave circular ring blocks, the plurality of transverse spring columns are arranged in the plurality of sound wave grooves, and it is a plurality of the horizontal spring post other end is connected respectively in a plurality of on the time shape stopper, it is a plurality of rotate the ball groove on having seted up on the rotation sound wave ring piece, it is a plurality of the rolling ball is installed respectively in a plurality of rotate the ball inslot, it is a plurality of it installs respectively in a plurality of to strike the spring post in the sound wave inslot, and it is a plurality of it connects respectively in a plurality of to strike the spring post other end on protruding type dwang.

2. The apparatus for recovering and purifying ethanol-cyclohexane-piperazine as a waste solvent according to claim 1, wherein the multi-stage rectification structure comprises: the system comprises a plurality of flow distribution plates, a plurality of U-shaped drainage tubes, a plurality of U-shaped steam drainage tubes, a plurality of S-shaped anti-backflow tubes, a plurality of flow discharge tubes, a pair of cooling boxes, a pair of cooling drainage coiled tubes, a pair of coolers, a pair of cooling liquid and a plurality of discharge flow distribution tubes;

the plurality of splitter plates are respectively and uniformly arranged in the rectification separation tower and the ethanol rectification tower, the plurality of S-shaped anti-reflux pipes are respectively inserted on the plurality of splitter plates, the plurality of U-shaped drainage pipes are respectively arranged on the plurality of splitter plates and are respectively connected on the plurality of S-shaped anti-reflux pipes, the plurality of discharge pipes are respectively arranged at the bottom ends of the plurality of splitter plates and are respectively connected on the plurality of S-shaped anti-reflux pipes, the plurality of U-shaped steam drainage pipes are respectively arranged on the plurality of splitter plates, a pair of cooling boxes are respectively arranged on the rectification separation tower and the ethanol rectification tower, a pair of cooling drainage coiling pipes are respectively arranged in the pair of cooling boxes, and a pair of cooling drainage coiling pipes are connected on the rectification separation tower and the ethanol rectification tower, the pair of coolers is respectively arranged on the pair of cooling boxes, the cooling liquid is arranged in the pair of cooling boxes, the plurality of discharge branch pipes are respectively arranged on the plurality of branch plates, and the plurality of discharge branch pipes are respectively connected to the plurality of U-shaped steam drainage pipes.

3. The apparatus for recovering and purifying ethanol-cyclohexane-piperazine as a waste solvent according to claim 2, wherein the flow dividing structure comprises: the device comprises a plurality of semicircular drainage tubes, a plurality of square-shaped filter blocks, a plurality of filter membranes and a plurality of U-shaped siphon drainage tubes;

the U-shaped siphon drainage tubes are connected with the bottom ends of the dehydration towers respectively, and are connected with the U-shaped siphon drainage tubes respectively.

4. A method for recovering and purifying waste solvent ethanol-cyclohexane-piperazine is characterized by comprising the following operation steps of S1 and rectification; step S2, liquid-liquid extraction; step S3, distillation; step S4, recycling;

the step S1: guiding the waste solvent ethanol-cyclohexane-piperazine in the waste water tank into a rectification separation tower, rectifying through a multi-section rectification structure to separate ethanol, cyclohexane and a small amount of water, and extracting the piperazine from the gas phase in the tower kettle of the rectification separation tower; obtaining an anhydrous piperazine product with the purity of more than or equal to 99.5 percent (wt);

the step S2: guiding the ethanol and cyclohexane obtained by rectification in the step S1 into an ethanol and cyclohexane extraction tower, adding a certain amount of water into the ethanol and cyclohexane extraction tower, and performing liquid-liquid extraction separation to obtain industrial cyclohexane with the purity of more than or equal to 99.5 percent (wt) on the upper layer; the lower layer is a water phase consisting of ethanol and water;

the step S3: distilling the water phase obtained by the extraction in the step S2, extracting an azeotrope of ethanol and water from steam at the top of the tower, and feeding the azeotrope into a membrane device at a certain flow rate to carry out dehydration in a dehydration tower to obtain industrial absolute ethanol with the purity of more than or equal to 99.9 percent (wt);

the step S4: and (4) returning the residual wastewater in the distillation tower kettle of the step S3 and the wastewater obtained by membrane dehydration to the extraction tower for continuous recycling.

5. The method for recovering and purifying ethanol-cyclohexane-piperazine as a waste solvent according to claim 4, wherein in the step S2, water is added at a volume concentration of 0.5-1000%.

6. The method and apparatus for recovering and purifying ethanol-cyclohexane-piperazine according to claim 5, wherein in step S3, ethanol is subjected to membrane dehydration in the form of steam, and the steam feeding flow rate is 0.1-2m 3/hr.

7. The method and the apparatus for recovering and purifying ethanol-cyclohexane-piperazine as the waste solvent according to claim 6, wherein in the step S1, the rectification conditions are as follows: the temperature of the bottom of the rectifying still is 64-112 ℃, the temperature of the liquid in the still is 62-110 ℃, the temperature of the top of the still is 60-85 ℃, and the reflux ratio is controlled to be 20: 1-0.5: 1.

8. The method and apparatus for recovering and purifying ethanol-cyclohexane-piperazine as a waste solvent according to claim 7, wherein in step S3, distillation conditions are as follows: the temperature of the bottom of the distillation kettle is 79-105 ℃, the temperature of liquid in the kettle is 78-102 ℃, the temperature of the top of the kettle is 78-95 ℃, and the reflux ratio is controlled to be 20: 1-0.5: 1.

9. The method and the equipment for recovering and purifying the waste solvent ethanol-cyclohexane-piperazine according to claim 8, wherein the method comprises the steps of directly rectifying the waste solvent, adding water for extracting and separating cyclohexane and ethanol, and performing membrane dehydration and separation on ethanol and water vapor.

Background

With the continuous development of the chemical industry, the application of related medical raw materials and intermediates is more common, and ethanol, cyclohexane and piperazine are widely applied. In the production process, a large amount of waste solvent containing ethanol, cyclohexane, piperazine, a small amount of water and trace medicinal components is generated, and because the purification difficulty is high, the waste solvent is mostly discarded and is not used, great waste is caused, and the environment is also polluted after incineration or discharge. The invention aims to overcome the defects in the prior art, and the scheme is developed by separating ethanol, cyclohexane and piperazine by rectification separation, extraction separation, distillation separation and coupling membrane dehydration separation, removing water and other impurities, purifying, recycling and recycling the solvent, reducing the generation of waste solvent and saving the production cost.

Disclosure of Invention

The invention aims to solve the problems, designs a method and equipment for recovering and purifying ethanol-cyclohexane-piperazine serving as a waste solvent, and solves part of the problems of the prior art.

The technical scheme of the invention for realizing the aim is as follows: a recovery and purification device for waste solvent ethanol-cyclohexane-piperazine comprises: the device comprises a waste water tank, a rectification separation tower, an ethanol and cyclohexane extraction tower, an ethanol rectification tower and a dehydration tower, wherein the waste water tank is connected to the rectification separation tower, the rectification separation tower is connected to the ethanol and cyclohexane extraction tower, the ethanol rectification tower is connected to the rectification separation tower, the dehydration tower is connected to the ethanol rectification tower, a vibration flow distribution structure is installed in the ethanol and cyclohexane extraction tower, a flow distribution structure is installed in the dehydration tower, and a multi-section rectification structure is installed in the ethanol rectification tower and the rectification separation tower;

the vibrations reposition of redundant personnel structure includes: the ultrasonic vibration device comprises a plurality of ultrasonic vibration shafts, a concave driving box, a sound wave driving machine, a sound wave rotation driving disc, a plurality of convex rotating rods, a plurality of knocking spring columns, a plurality of rotation sound wave circular ring blocks, a plurality of concave circular ring blocks, a plurality of longitudinal slideways, a plurality of longitudinal sliders, a plurality of clip stoppers, a plurality of transverse slideways, a plurality of transverse sliders, a plurality of transverse spring columns, a plurality of sealant, a plurality of longitudinal spring columns and a plurality of auxiliary balls;

the ethanol and cyclohexane extraction tower is provided with a plurality of sound wave grooves, a plurality of transverse slideways are respectively and oppositely arranged in the sound wave grooves in parallel, a plurality of transverse sliders are respectively arranged on a plurality of square-shaped limiting blocks, a plurality of transverse sliders are respectively and movably inserted in the transverse slideways, a plurality of longitudinal slideways are respectively and oppositely arranged in the square-shaped limiting blocks in parallel, a plurality of longitudinal sliders are respectively arranged on two sides of a plurality of concave circular ring blocks, a plurality of longitudinal sliders are respectively and movably inserted in the longitudinal slideways, a plurality of rotary sound wave circular ring blocks are respectively and movably inserted in the concave circular ring blocks, a plurality of ultrasonic vibration shafts are respectively inserted on the rotary sound wave circular ring blocks, the concave driving box is arranged on the rectification separation tower, and the sound wave driver is arranged on the concave driving box, the sound wave rotation driving disc is arranged on the driving end of the sound wave driver, a plurality of knocking grooves are formed in the sound wave rotation driving disc, a plurality of convex rotating rods are respectively inserted into the knocking grooves through bearings, a plurality of longitudinal spring columns are respectively arranged on a plurality of clip-shaped limiting blocks, the other ends of the plurality of longitudinal spring columns are respectively connected to the plurality of concave circular ring blocks, the plurality of transverse spring columns are arranged in the plurality of sound wave grooves, and it is a plurality of the horizontal spring post other end is connected respectively in a plurality of on the time shape stopper, it is a plurality of rotate the ball groove on having seted up on the rotation sound wave ring piece, it is a plurality of the rolling ball is installed respectively in a plurality of rotate the ball inslot, it is a plurality of it installs respectively in a plurality of to strike the spring post in the sound wave inslot, and it is a plurality of it connects respectively in a plurality of to strike the spring post other end on protruding type dwang.

Preferably, the multi-stage rectification structure comprises: the system comprises a plurality of flow distribution plates, a plurality of U-shaped drainage tubes, a plurality of U-shaped steam drainage tubes, a plurality of S-shaped anti-backflow tubes, a plurality of flow discharge tubes, a pair of cooling boxes, a pair of cooling drainage coiled tubes, a pair of coolers, a pair of cooling liquid and a plurality of discharge flow distribution tubes;

the plurality of splitter plates are respectively and uniformly arranged in the rectification separation tower and the ethanol rectification tower, the plurality of S-shaped anti-reflux pipes are respectively inserted on the plurality of splitter plates, the plurality of U-shaped drainage pipes are respectively arranged on the plurality of splitter plates and are respectively connected on the plurality of S-shaped anti-reflux pipes, the plurality of discharge pipes are respectively arranged at the bottom ends of the plurality of splitter plates and are respectively connected on the plurality of S-shaped anti-reflux pipes, the plurality of U-shaped steam drainage pipes are respectively arranged on the plurality of splitter plates, a pair of cooling boxes are respectively arranged on the rectification separation tower and the ethanol rectification tower, a pair of cooling drainage coiling pipes are respectively arranged in the pair of cooling boxes, and a pair of cooling drainage coiling pipes are connected on the rectification separation tower and the ethanol rectification tower, the pair of coolers is respectively arranged on the pair of cooling boxes, the cooling liquid is arranged in the pair of cooling boxes, the plurality of discharge branch pipes are respectively arranged on the plurality of branch plates, and the plurality of discharge branch pipes are respectively connected to the plurality of U-shaped steam drainage pipes.

Preferably, the flow dividing structure includes: the device comprises a plurality of semicircular drainage tubes, a plurality of square-shaped filter blocks, a plurality of filter membranes and a plurality of U-shaped siphon drainage tubes;

the U-shaped siphon drainage tubes are connected with the bottom ends of the dehydration towers respectively, and are connected with the U-shaped siphon drainage tubes respectively.

A method for recovering and purifying waste solvent ethanol-cyclohexane-piperazine comprises the following operation steps of S1 and rectification; step S2, liquid-liquid extraction; step S3, distillation; step S4, recycling;

the step S1: guiding the waste solvent ethanol-cyclohexane-piperazine in the waste water tank into a rectification separation tower, rectifying through a multi-section rectification structure to separate ethanol, cyclohexane and a small amount of water, and extracting the piperazine from the gas phase in the tower kettle of the rectification separation tower; obtaining an anhydrous piperazine product with the purity of more than or equal to 99.5 percent (wt);

the step S2: guiding the ethanol and cyclohexane obtained by rectification in the step S1 into an ethanol and cyclohexane extraction tower, adding a certain amount of water into the ethanol and cyclohexane extraction tower, and performing liquid-liquid extraction separation to obtain industrial cyclohexane with the purity of more than or equal to 99.5 percent (wt) on the upper layer; the lower layer is a water phase consisting of ethanol and water;

the step S3: distilling the water phase obtained by the extraction in the step S2, extracting an azeotrope of ethanol and water from steam at the top of the tower, and feeding the azeotrope into a membrane device at a certain flow rate to carry out dehydration in a dehydration tower to obtain industrial absolute ethanol with the purity of more than or equal to 99.9 percent (wt);

the step S4: and (4) returning the residual wastewater in the distillation tower kettle of the step S3 and the wastewater obtained by membrane dehydration to the extraction tower for continuous recycling.

In the step S2, the volume concentration of the added water is 0.5-1000%.

In the step S3, ethanol is subjected to membrane dehydration in the form of steam, and the steam feeding flow rate is 0.1-2m 3/h.

In the step S1, the rectification conditions are as follows: the temperature of the bottom of the rectifying still is 64-112 ℃, the temperature of the liquid in the still is 62-110 ℃, the temperature of the top of the still is 60-85 ℃, and the reflux ratio is controlled to be 20: 1-0.5: 1.

In the step S3, the distillation conditions are as follows: the temperature of the bottom of the distillation kettle is 79-105 ℃, the temperature of liquid in the kettle is 78-102 ℃, the temperature of the top of the kettle is 78-95 ℃, and the reflux ratio is controlled to be 20: 1-0.5: 1.

The method also comprises the steps of directly rectifying the waste solvent, adding water for extraction and separation of cyclohexane and ethanol, and carrying out membrane dehydration and separation on ethanol and water vapor.

The method and the equipment for recovering and purifying the waste solvent ethanol-cyclohexane-piperazine, which are manufactured by the technical scheme of the invention, are used for separating the components in the waste solvent ethanol-cyclohexane-piperazine, removing water and various impurities by the methods of rectification separation, extraction separation, distillation separation and coupling membrane dehydration separation, through a series of processes with low energy consumption, the waste solvent with the purity of only 50-60% (wt) ethanol, 30-45% (wt) cyclohexane and 3-8% (wt) piperazine is purified to industrial absolute ethanol with the purity of more than or equal to 99.9% (wt), industrial cyclohexane with the purity of more than or equal to 99.5% (wt) and anhydrous piperazine with the purity of more than or equal to 99.5% (wt), so that the waste solvent ethanol-cyclohexane-piperazine is recycled, the pollution degree of the waste solvent to the environment is reduced, the purified solvent can be recycled, and the production cost is saved. The purification method provided by the invention also has the advantages of high yield, low energy consumption, capability of recycling, simple and convenient production process, stable operation, suitability for industrial production and the like.

Drawings

FIG. 1 is a schematic flow diagram of a method and equipment for recovering and purifying ethanol-cyclohexane-piperazine serving as a waste solvent.

FIG. 2 is a schematic sectional view of the waste solvent ethanol-cyclohexane-piperazine recovery and purification method and apparatus in the present invention.

Fig. 3 is a schematic top sectional view of the method and apparatus for recovering and purifying ethanol-cyclohexane-piperazine as a waste solvent according to the present invention.

Fig. 4 is an enlarged view of a portion "a" in fig. 2.

Fig. 5 is an enlarged view of a portion "B" in fig. 3.

In the figure: 1. a wastewater tank; 2. a rectification separation column; 3. an ethanol and cyclohexane extraction tower; 4. an ethanol rectification column; 5. a dehydration tower; 6. ultrasonic vibration shaft; 7. a concave drive box; 8. a sound wave driver; 9. the disk is driven by sound wave rotation; 10. a convex rotating rod; 11. knocking the spring post; 12. rotating the acoustic ring block; 13. a longitudinal spring post; 14. a concave circular ring block; 15. a longitudinal slideway; 16. a longitudinal slide block; 17. a clip-shaped limiting block; 18. a transverse slideway; 19. a transverse slide block; 20. a transverse spring post.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings, and as shown in fig. 1 to 5, an apparatus for recovering and purifying ethanol-cyclohexane-piperazine as a waste solvent comprises: the device comprises a wastewater tank 1, a rectification separation tower 2, an ethanol and cyclohexane extraction tower 3, an ethanol rectification tower 4 and a dehydration tower 5, wherein the wastewater tank 1 is connected to the rectification separation tower 2, the rectification separation tower 2 is connected to the ethanol and cyclohexane extraction tower 3, the ethanol rectification tower 4 is connected to the rectification separation tower 2, the dehydration tower 5 is connected to the ethanol rectification tower 4, a vibration flow distribution structure is installed in the ethanol and cyclohexane extraction tower 3, a flow distribution structure is installed in the dehydration tower 5, and a multi-section rectification structure is installed in the ethanol rectification tower 4 and the rectification separation tower 2; the vibrations reposition of redundant personnel structure includes: the ultrasonic vibration device comprises a plurality of ultrasonic vibration shafts 6, a concave driving box 7, a sound wave driving machine 8, a sound wave rotation driving disc 9, a plurality of convex rotating rods 10, a plurality of knocking spring columns 11, a plurality of rotating sound wave circular ring blocks 12, a plurality of concave circular ring blocks 14, a plurality of longitudinal slideways 15, a plurality of longitudinal sliders 16, a plurality of clip-shaped limiting blocks 17, a plurality of transverse slideways 18, a plurality of transverse sliders 19, a plurality of transverse spring columns 20, a plurality of sealing glue, a plurality of longitudinal spring columns 13 and a plurality of auxiliary balls; the ethanol and cyclohexane extraction tower 3 is provided with a plurality of sound wave grooves, a plurality of transverse slideways 18 are respectively and relatively arranged in the sound wave grooves in parallel, a plurality of transverse sliders 19 are respectively arranged on a plurality of square-shaped limiting blocks 17, a plurality of transverse sliders 19 are respectively and movably inserted in the transverse slideways 18, a plurality of longitudinal slideways 15 are respectively and relatively arranged in the square-shaped limiting blocks 17 in parallel, a plurality of longitudinal sliders 16 are respectively arranged on two sides of a plurality of concave circular ring blocks 14, a plurality of longitudinal sliders 16 are respectively and movably inserted in the longitudinal slideways 15, a plurality of rotary sound wave circular ring blocks 12 are respectively and movably inserted in the concave circular ring blocks 14, a plurality of ultrasonic vibration shafts 6 are respectively inserted in the rotary sound wave circular ring blocks 12, and the concave driving box 7 is arranged on the rectification separation tower 2, the sound wave driving machine 8 is arranged on the concave driving box 7, the sound wave rotation driving disc 9 is arranged on the driving end of the sound wave driving machine 8, a plurality of knocking grooves are arranged on the sound wave rotation driving disc 9, a plurality of convex rotating rods 10 are respectively inserted into the plurality of knocking grooves through bearings, a plurality of longitudinal spring columns 13 are respectively arranged on the plurality of clip-shaped limiting blocks 17, the other ends of the plurality of longitudinal spring columns 13 are respectively connected onto the plurality of concave circular ring blocks 14, a plurality of transverse spring columns 20 are arranged in the plurality of sound wave grooves, the other ends of the plurality of transverse spring columns 20 are respectively connected onto the plurality of clip-shaped limiting blocks 17, a plurality of rotation ball grooves are arranged on the plurality of rotation sound wave circular ring blocks 12, a plurality of rotation balls are respectively arranged in the plurality of rotation ball grooves, a plurality of knocking spring columns 11 are respectively arranged in the plurality of sound wave grooves, the other ends of the knocking spring columns 11 are respectively connected to the convex rotating rods 10; the multi-stage rectification structure comprises: the system comprises a plurality of flow distribution plates, a plurality of U-shaped drainage tubes, a plurality of U-shaped steam drainage tubes, a plurality of S-shaped anti-backflow tubes, a plurality of flow discharge tubes, a pair of cooling boxes, a pair of cooling drainage coiled tubes, a pair of coolers, a pair of cooling liquid and a plurality of discharge flow distribution tubes; the plurality of splitter plates are respectively and uniformly arranged in the rectification separation tower 2 and the ethanol rectification tower 4, the plurality of S-shaped anti-reflux pipes are respectively inserted on the plurality of splitter plates, the plurality of U-shaped drainage pipes are respectively arranged on the plurality of splitter plates and are respectively connected on the plurality of S-shaped anti-reflux pipes, the plurality of discharge pipes are respectively arranged at the bottom ends of the plurality of splitter plates and are respectively connected on the plurality of S-shaped anti-reflux pipes, the plurality of U-shaped steam drainage pipes are respectively arranged on the plurality of splitter plates, a pair of cooling boxes are respectively arranged on the separation tower 2 and the ethanol rectification tower 4, a pair of cooling drainage coil pipes are respectively arranged in the pair of cooling boxes, and a pair of cooling drainage coil pipes are connected on the rectification separation tower 2 and the ethanol rectification tower 4, a pair of said coolers are respectively mounted on a pair of said cooling boxes, said cooling liquid is disposed in a pair of said cooling boxes, a plurality of said discharge branch pipes are respectively mounted on a plurality of said branch plates, and a plurality of said discharge branch pipes are respectively connected to a plurality of said U-shaped vapor draft tubes; the shunting structure includes: the device comprises a plurality of semicircular drainage tubes, a plurality of square-shaped filter blocks, a plurality of filter membranes and a plurality of U-shaped siphon drainage tubes; the U-shaped siphon drainage tubes are connected to the bottom ends of the dehydration towers 5 respectively, and the U-shaped siphon drainage tubes are connected to the semicircular drainage tubes respectively.

A method for recovering and purifying waste solvent ethanol-cyclohexane-piperazine comprises the following operation steps of S1 and rectification; step S2, liquid-liquid extraction; step S3, distillation; step S4, recycling;

the step S1: guiding the waste solvent ethanol-cyclohexane-piperazine in the waste water tank 1 into a rectification separation tower 2, rectifying through a multi-stage rectification structure to separate ethanol, cyclohexane and a small amount of water, and extracting the piperazine from the gas phase at the tower bottom of the rectification separation tower 2; obtaining an anhydrous piperazine product with the purity of more than or equal to 99.5 percent (wt);

the step S2: guiding the ethanol and cyclohexane obtained by rectification in the step S1 into an ethanol and cyclohexane extraction tower 3, adding a certain amount of water into the ethanol and cyclohexane extraction tower 3, and performing liquid-liquid extraction separation to obtain industrial cyclohexane with the purity of more than or equal to 99.5 percent (wt) on the upper layer; the lower layer is a water phase consisting of ethanol and water;

the step S3: distilling the water phase obtained by the extraction in the step S2, extracting an azeotrope of ethanol and water from steam at the top of the tower, and feeding the azeotrope into a membrane device at a certain flow rate to carry out dehydration in a dehydration tower 5 to obtain industrial absolute ethanol with the purity of more than or equal to 99.9 percent (wt);

the step S4: and (4) returning the residual wastewater in the distillation tower kettle of the step S3 and the wastewater obtained by membrane dehydration to the extraction tower for continuous recycling.

In the step S2, the volume concentration of the added water is 0.5-1000%.

In the step S3, ethanol is subjected to membrane dehydration in the form of steam, and the steam feeding flow rate is 0.1-2m 3/h.

In the step S1, the rectification conditions are as follows: the temperature of the bottom of the rectifying still is 64-112 ℃, the temperature of the liquid in the still is 62-110 ℃, the temperature of the top of the still is 60-85 ℃, and the reflux ratio is controlled to be 20: 1-0.5: 1.

In the step S3, the distillation conditions are as follows: the temperature of the bottom of the distillation kettle is 79-105 ℃, the temperature of liquid in the kettle is 78-102 ℃, the temperature of the top of the kettle is 78-95 ℃, and the reflux ratio is controlled to be 20: 1-0.5: 1.

The method also comprises the steps of directly rectifying the waste solvent, adding water for extraction and separation of cyclohexane and ethanol, and carrying out membrane dehydration and separation on ethanol and water vapor.

The present embodiment is characterized by comprising: the device comprises a waste water tank, a rectification separation tower, an ethanol and cyclohexane extraction tower, an ethanol rectification tower and a dehydration tower, wherein the waste water tank is connected to the rectification separation tower, the rectification separation tower is connected to the ethanol and cyclohexane extraction tower, the ethanol rectification tower is connected to the rectification separation tower, the dehydration tower is connected to the ethanol rectification tower, a vibration flow distribution structure is installed in the ethanol and cyclohexane extraction tower, a flow distribution structure is installed in the dehydration tower, and a multi-section rectification structure is installed in the ethanol rectification tower and the rectification separation tower; the vibration shunting structure comprises: the ultrasonic vibration device comprises a plurality of ultrasonic vibration shafts, a concave driving box, a sound wave driving machine, a sound wave rotation driving disc, a plurality of convex rotating rods, a plurality of knocking spring columns, a plurality of rotation sound wave circular ring blocks, a plurality of concave circular ring blocks, a plurality of longitudinal slideways, a plurality of longitudinal sliders, a plurality of clip stoppers, a plurality of transverse slideways, a plurality of transverse sliders, a plurality of transverse spring columns, a plurality of sealant, a plurality of longitudinal spring columns and a plurality of auxiliary balls; the ethanol and cyclohexane extraction tower is provided with a plurality of sound wave grooves, a plurality of transverse slideways are respectively arranged in the sound wave grooves in a relative parallel way, a plurality of transverse sliders are respectively arranged on a plurality of square-shaped limiting blocks, the transverse sliders are respectively movably inserted in the transverse slideways, a plurality of longitudinal slideways are respectively arranged in the square-shaped limiting blocks in a relative parallel way, a plurality of longitudinal sliders are respectively arranged at two sides of a plurality of concave circular ring blocks, the longitudinal sliders are respectively movably inserted in the longitudinal slideways, a plurality of rotary sound wave circular ring blocks are respectively movably inserted in the concave circular ring blocks, a plurality of ultrasonic vibration shafts are respectively inserted in the rotary sound wave circular ring blocks, a concave driving box is arranged on the rectification separation tower, a sound wave driver is arranged on the concave driving box, a sound wave rotary driving disc is arranged on a sound wave driver end, a plurality of knocking grooves are arranged on the sound wave rotary driving disc, the plurality of convex rotating rods are inserted into the plurality of knocking grooves through bearings respectively, the plurality of longitudinal spring columns are installed on the plurality of clip-shaped limiting blocks respectively, the other ends of the plurality of longitudinal spring columns are connected to the plurality of concave circular ring blocks respectively, the plurality of transverse spring columns are installed in the plurality of sound wave grooves, the other ends of the plurality of transverse spring columns are connected to the plurality of clip-shaped limiting blocks respectively, the plurality of rotating sound wave circular ring blocks are provided with a plurality of rotating ball grooves, the plurality of rotating balls are installed in the plurality of rotating ball grooves respectively, the plurality of knocking spring columns are installed in the plurality of sound wave grooves respectively, and the other ends of the plurality of knocking spring columns are connected to the plurality of convex rotating rods respectively; the method comprises the steps of separating components in the waste solvent ethanol-cyclohexane-piperazine, removing water and various impurities, and purifying the waste solvent ethanol with the purity of only 50-60 percent (wt), 30-45 percent (wt) and 3-8 percent (wt) of piperazine to industrial absolute ethanol with the purity of more than or equal to 99.9 percent (wt), industrial cyclohexane with the purity of more than or equal to 99.5 percent (wt) and anhydrous piperazine with the purity of more than or equal to 99.5 percent (wt) through a series of processes with low energy consumption, so that the waste solvent ethanol-cyclohexane-piperazine is recycled, the pollution degree of the waste solvent to the environment is reduced, the purified solvent can be recycled, and the production cost is saved. The purification method provided by the invention also has the advantages of high yield, low energy consumption, capability of recycling, simple and convenient production process, stable operation, suitability for industrial production and the like.

All the electrical components in the present application are connected with the power supply adapted to the electrical components through the wires, and an appropriate controller should be selected according to actual conditions to meet the control requirements, and specific connection and control sequences should be obtained.

Example 1: wastewater in the wastewater tank 1 is drained into a rectification separation tower 2, a waste solvent containing 51% of ethanol, 43% of cyclohexane and 5% of piperazine is taken for rectification, and the rectification conditions are as follows: the temperature of the bottom of the rectifying kettle is 110 ℃, the temperature of liquid in the kettle is 109 ℃, the temperature of the top of the kettle is 62-77 ℃, and the reflux ratio is controlled to be 5: 1; separating out ethanol, cyclohexane and a small amount of water; collecting piperazine from a tower kettle, canning after detection is qualified, filling nitrogen for storage, namely obtaining anhydrous piperazine with the purity of more than or equal to 99.5 percent (wt), rectifying wastewater through a multi-stage rectification structure, adding ethanol and cyclohexane obtained by rectification into water with the volume of 1.53 times of that of a waste solvent for extraction, obtaining cyclohexane on the upper layer, canning after detection is qualified, filling nitrogen for storage, namely industrial grade cyclohexane with the purity of more than or equal to 99.5 percent (wt); the lower layer obtains a water phase consisting of ethanol and water, the water phase runs through a sound wave driver 8 in a concave driving box 7 to drive a sound wave rotation driving disc 9 on the driving end of the sound wave driver 8 to rotate, the sound wave rotation driving disc 9 drives a plurality of convex rotating bars 10 thereon to rotate, the plurality of rotary convex rotating bars 10 rotate to knock a plurality of ultrasonic vibration shafts 6, the ethanol and the mixed liquid in the cyclohexane extraction tower 3 are ultrasonically vibrated through the plurality of ultrasonic vibration shafts 6 to accelerate extraction, the convex rotating bars 10 on the ethanol and the cyclohexane extraction tower are respectively extruded through a plurality of knocking spring columns 11, so that the convex rotating bars 10 knock ultrasonic vibration, part of vibration is transmitted to the rotary sound wave ring blocks 12 through the plurality of ultrasonic vibration shafts 6, and the rotary sound wave ring blocks 12 respectively rotate in the concave ring blocks 14, through the telescopic movement in the longitudinal slide 15 of the longitudinal slide 16 on a plurality of concave type ring pieces 14 in a plurality of shape stopper 17 respectively, convert some fore-and-aft external force into elastic deformation through a plurality of longitudinal spring posts 13 simultaneously, simultaneously through the telescopic movement in a plurality of transverse slide 18 respectively of the horizontal slider 19 on the shape stopper 17 that returns to avoid ultrasonic vibration to transmit on ethanol and cyclohexane extraction tower 3, with the aqueous phase that above-mentioned extraction obtained, the distillation condition is: the temperature of the bottom of the distillation kettle is 100 ℃, the temperature of liquid in the kettle is 95 ℃, the temperature of the top of the kettle is 78-90 ℃, and the reflux ratio is controlled to be 1: 1. Extracting azeotrope of ethanol and water from the steam at the tower top, membrane dehydrating the steam at the flow rate of 1 cubic meter per hour, canning the qualified ethanol, filling nitrogen for storage to obtain industrial absolute ethanol with the purity of more than or equal to 99.9 percent (wt), and returning the residual wastewater in the distillation tower kettle and the wastewater obtained by membrane dehydration to the extraction tower for continuous recycling.

Example 2: taking a waste solvent containing 56% of ethanol, 35% of cyclohexane and 8% of piperazine, and rectifying under the following conditions: the temperature of the bottom of the rectifying kettle is 110 ℃, the temperature of liquid in the kettle is 109 ℃, the temperature of the top of the kettle is 62-77 ℃, and the reflux ratio is controlled to be 3: 1; separating out ethanol, cyclohexane and a small amount of water; collecting piperazine from the tower kettle, canning after detection is qualified, filling nitrogen for storage to obtain anhydrous piperazine with the purity of more than or equal to 99.5 percent (wt), adding water with the volume of 0.18 time that of the waste solvent into the ethanol and cyclohexane obtained by rectification for extraction to obtain cyclohexane on the upper layer, canning after detection is qualified, filling nitrogen for storage to obtain industrial grade cyclohexane with the purity of more than or equal to 99.5 percent (wt); the lower layer is an aqueous phase consisting of ethanol and water, and the aqueous phase obtained by the extraction is distilled under the following conditions: the temperature of the bottom of the distillation kettle is 100 ℃, the temperature of liquid in the kettle is 90 ℃, the temperature of the top of the kettle is 78-90 ℃, and the reflux ratio is controlled to be 1: 1. Extracting azeotrope of ethanol and water from the steam at the tower top, membrane dehydrating the steam at the flow rate of 0.8 cubic meter per hour, canning the qualified ethanol, filling nitrogen for storage to obtain industrial absolute ethanol with the purity of more than or equal to 99.9 percent (wt), and returning the residual wastewater in the distillation tower kettle and the wastewater obtained by membrane dehydration to the extraction tower for continuous recycling.

The technical indexes of the purified piperazine obtained in the embodiments 1-2 are shown in the table one:

watch 1

The technical indexes of the purified industrial cyclohexane of the examples 1-2 are shown in the following table two:

watch two

The technical indexes of the industrial grade absolute ethyl alcohol purified in the embodiments 1-2 are shown in the third table:

watch III

The technical solutions described above only represent the preferred technical solutions of the present invention, and some possible modifications to some parts of the technical solutions by those skilled in the art all represent the principles of the present invention, and fall within the protection scope of the present invention.