Ethanol recovery system and method for etherification of pregnene carboxylic acid lactone

Abstract

The invention belongs to the technical field of organic synthesis chemistry and environmental protection, and particularly relates to a pregnene carboxylic acid lactone etherification ethanol recovery system and method.The pregnene carboxylic acid lactone etherification ethanol recovery system comprises a mother liquor distillation recovery tank, and a mother liquor output tank, a distillation tower and a mother liquor input tank are arranged at the left end, the middle end and the right end of the interior of the mother liquor distillation recovery tank correspondingly; the distillation tower is respectively communicated with a mother liquor input tank and a mother liquor output tank through pipelines, a spiral condenser is arranged in the mother liquor input tank, and one end of the spiral condenser penetrates through the mother liquor input tank and is communicated with an ethanol collecting tank through the mother liquor input tank; and the other end of the spiral condenser penetrates through the mother liquor input tank and is communicated with the distillation tower through the mother liquor input tank. The method solves the problem that the treatment difficulty is increased due to the fact that ethanol in the pregnene carboxylic acid lactone etherification mother liquor is difficult to recover, a large amount of wastewater is generated in the pregnene carboxylic acid lactone etherification process, the production cost and the environmental protection burden are reduced, the added value of a finished product is improved, and the product competitiveness is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthetic chemistry and environmental protection, and particularly relates to an ethanol recovery system and method for etherification of pregnenyl carboxylic acid lactone. Background Art

[0002] The etherification reaction of pregnenyl carboxylic acid lactone is an important step in organic synthesis, usually involving ethanol as a solvent or reactant. Ethanol can promote the reaction and contribute to the formation of products due to its good solubility and reactivity. However, after the etherification reaction is completed, if the ethanol is not recovered, a large amount of wastewater will be generated. The treatment of the wastewater will increase the production cost and the burden of environmental protection. In order to reduce the cost of treating wastewater and the burden of environmental protection, the ethanol in the etherification reaction needs to be recovered. At present, an absorption system has been used to recover ethanol. Although ethanol can be recovered to a certain extent, the recovery effect is poor, the energy consumption is high, and secondary pollution is easily generated.

[0003] In the prior art, there are studies on the problems of poor recovery effect and high energy consumption in the current ethanol recovery method, such as patent application CN113680176A-an ethanol recovery system, which increases the number of absorption times of ethanol in tail gas by adding a spray head, and solves the problem of poor recovery effect in the current ethanol recovery method, but the existing ethanol recovery system can only recover ethanol in tail gas, but it is difficult to recover and apply the ethanol in the etherification mother liquor of pregnenyl carboxylic acid lactone, which makes it difficult to avoid the generation of a large amount of wastewater in the etherification process of pregnenyl carboxylic acid lactone, thereby increasing the wastewater treatment cost and the burden on environmental protection. Therefore, a new technical solution is needed to solve the above technical problems. Summary of the invention

[0004] The object of the present invention is to provide an ethanol recovery system and method for the etherification of pregnenyl carboxylic acid lactone, so as to solve the problems mentioned in the above background technology that the current ethanol recovery system is difficult to recover ethanol in the mother liquor of the etherification of pregnenyl carboxylic acid lactone, resulting in difficulty in avoiding the generation of a large amount of wastewater in the etherification process of pregnenyl carboxylic acid lactone, thereby increasing the wastewater treatment cost and the burden on environmental protection.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: an ethanol recovery system for the etherification of pregnenyl carboxylic acid lactone, comprising a mother liquor distillation recovery tank, wherein a mother liquor output tank, a distillation tower and a mother liquor input tank are respectively arranged at the left, middle and right ends of the interior of the mother liquor distillation recovery tank, wherein the distillation tower is connected to the mother liquor input tank and the mother liquor output tank through pipelines, respectively, a spiral condenser is arranged inside the mother liquor input tank, one end of the spiral condenser penetrates a side wall of the mother liquor input tank and extends to the outside of the mother liquor input tank to be connected with an ethanol collection tank arranged on the right side of the outside of the mother liquor distillation recovery tank, and the other end of the spiral condenser penetrates the other side wall of the mother liquor input tank and extends to the outside of the mother liquor input tank to be connected with the distillation tower.

[0006] Furthermore, the interior of the distillation tower is vertically provided with a partition and is divided into an evaporation zone and a wastewater zone by the partition, and a liquid level sensor is provided on the top of the partition; a vacuum unit is fixed on the distillation tower; a guide plate is obliquely provided on the inner top of the distillation tower, a condenser is provided above the guide plate, the highest point of the guide plate is located at the top of the evaporation zone, and the lowest point of the guide plate is located at the top of the wastewater zone and a guide hole connected to the wastewater zone is also provided there.

[0007] Furthermore, the bottom end of the wastewater zone is connected to a wastewater collection tank through a pipeline, and the wastewater collection tank is arranged on the left side of the outside of the mother liquid distillation recovery tank; the side end of the evaporation zone is connected to the mother liquid input tank through a pipeline, and the bottom end of the evaporation zone is connected to the mother liquid output tank through a pipeline, and an evaporator and a stirrer are arranged in the evaporation zone.

[0008] The ethanol recovery system for etherification of pregnenyl carboxylic acid lactone provided above is used to recover the ethanol in the etherification process of pregnenyl carboxylic acid lactone, and the specific steps are as follows: S1, transporting the etherified mother liquor of pregnenyl carboxylic acid lactone to a distillation tower through a liquid pump via a mother liquor input tank for negative pressure distillation treatment; S2, the steam generated in the negative pressure distillation process is first condensed by the condenser to form wastewater, which slides into the wastewater area through the guide hole of the guide plate and is discharged into the wastewater collection tank through the pipeline, and then condensed by the spiral condenser using the temperature of the mother liquid input tank to form ethanol, which is discharged into the ethanol collection tank; S3, testing the water content of the ethanol in the ethanol collection tank, and when the water content of the ethanol is ≧0.5%, continuously conveying the etherification mother liquor of pregnenyl carboxylic acid lactone for continuous recovery treatment; S4, after the distillation tower is heated and evaporated for 4 to 5 minutes, the evaporator and the agitator in the distillation tower are first closed, and then the etherification mother liquor of pregnenyl carboxylic acid lactone in the distillation tower is completely discharged through the mother liquor output tank at one time, and then the evaporator and the agitator in the distillation tower are opened to repeat S1 to S4.

[0009] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention utilizes the distillation effect of a distillation tower to form ethanol vapor from the etherification mother liquor of pregnenyl carboxylic acid lactone under the effect of distillation, and then uses a spiral condenser arranged inside a mother liquor input tank to cool and condense the ethanol vapor after entering the spiral condenser using the temperature of the mother liquor input tank itself, so that the ethanol in the etherification mother liquor of pregnenyl carboxylic acid lactone can be recovered into an ethanol collecting tank, thereby realizing the recycling of ethanol and effectively reducing the discharge of hazardous wastes. The distillation tower is connected to the mother liquor output tank through a pipeline, so that the etherification mother liquor of pregnenyl carboxylic acid lactone after the ethanol is recovered can be returned to the production process of pregnenyl carboxylic acid lactone, effectively avoiding the problem that a large amount of wastewater is generated in the etherification process of pregnenyl carboxylic acid lactone due to the difficulty in recovering the ethanol in the etherification mother liquor of pregnenyl carboxylic acid lactone, effectively reducing the production cost and environmental burden of pregnenyl carboxylic acid lactone, improving the added value of the finished product of pregnenyl carboxylic acid lactone, and ensuring the product competitiveness of pregnenyl carboxylic acid lactone; 2. The present invention forms an evaporation zone and a wastewater zone inside the distillation tower by vertically setting a partition inside the distillation tower under the partition, thereby effectively improving the quality of ethanol recovery and reducing the water content of the recovered ethanol. At the same time, the ethanol vapor can be separated from the wastewater under the action of the condenser and the spiral condenser, thereby solving the influence of the recycled ethanol on the quality. The liquid level sensor set on the top of the partition makes the liquid level of the etherification mother liquor of pregnenyl carboxylic acid lactone within a controllable range, thereby ensuring the continuity of the recovered ethanol. 3. The present invention uses a guide plate obliquely arranged on the inner top of the distillation tower to enable wastewater to slide more quickly and accurately into the wastewater area through the guide hole, so that the wastewater can be recovered in the wastewater collection tank, effectively reducing the difficulty and cost of wastewater treatment and solving the problem of environmental pollution. The vacuum unit is fixed on the distillation tower to make the distillation of the etherification mother liquor of pregnenyl carboxylic acid lactone in a negative pressure state, so that the water in the ethanol vapor can be condensed in advance, effectively reducing the water content of the recovered ethanol and solving the problem of the influence of the recycled ethanol on the quality. 4. The present invention adopts the ethanol recovery system to recover the ethanol in the etherification process of pregnenyl carboxylic acid lactone, making the treatment process simpler, more environmentally friendly, and safer. At the same time, the ethanol recovery rate reaches more than 70%, so that the yield and quality of the etherified product can reach the standard value, which not only reduces the amount of hazardous waste, but also reduces the use of new ethanol, effectively reduces the production cost, and alleviates the pressure of environmental protection treatment, laying a good foundation for the preparation of etherified products by etherification recovery of ethanol in the later products. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the ethanol recovery system of the present invention.

[0011] Among them: 1. Mother liquor distillation recovery tank; 2. Mother liquor output tank; 3. Distillation tower; 301. Evaporation area; 302. Wastewater area; 4. Mother liquor input tank; 5. Spiral condenser; 6. Ethanol collection tank; 7. Partition; 8. Vacuum unit; 9. Guide plate; 10. Condenser; 11. Diversion hole; 12. Wastewater collection tank; 13. Evaporator; 14. Agitator; 15. Liquid level sensor. DETAILED DESCRIPTION

[0012] The following examples are used to further illustrate the content of the present invention, but do not limit the application of the present invention.

[0013] See also Figure 1 The present embodiment provides an ethanol recovery system for etherification of pregnenyl carboxylic acid lactone, comprising a mother liquor distillation recovery tank 1 for recovering ethanol from a mother liquor etherified from pregnenyl carboxylic acid lactone, a mother liquor output tank 2 for outputting a mother liquor etherified from pregnenyl carboxylic acid lactone after ethanol recovery, a distillation tower 3 for distilling out ethanol vapor, and a mother liquor input tank 4 for inputting a mother liquor etherified from pregnenyl carboxylic acid lactone containing ethanol, respectively arranged at the left, middle, and right ends of the interior of the mother liquor distillation recovery tank 1, the distillation tower 3 being connected to the mother liquor input tank 4 and the mother liquor output tank 2 through pipelines, a spiral condenser 5 for condensing ethanol vapor being arranged inside the mother liquor input tank 4, one end of the spiral condenser 5 passing through a side wall of the mother liquor input tank 4 and extending to the outside of the mother liquor input tank 4 and being connected to an ethanol collecting tank 6 arranged on the right side of the outside of the mother liquor distillation recovery tank 1 and used for collecting ethanol, the other end of the spiral condenser 5 passing through the other side wall of the mother liquor input tank 4 and extending to the outside of the mother liquor input tank 4 and being connected to the distillation tower 3; The interior of the distillation tower 3 is vertically provided with a partition 7 for separation, and is divided into an evaporation zone 301 and a wastewater zone 302 by the partition 7, and a liquid level sensor 15 for monitoring the liquid level of the etherification mother liquid of pregnenyl carboxylic acid lactone is provided on the top of the partition 7. A vacuum unit 8 for intermittent air extraction is fixed on the distillation tower 3 to form a negative pressure environment in the distillation tower 3. A guide plate 9 for guiding the flow direction of the wastewater is obliquely provided on the inner top of the distillation tower 3; A condenser 10 for condensing waste water in ethanol vapor is arranged above the guide plate 9, the highest point of the guide plate 9 is located at the top of the evaporation area 301, and the lowest point of the guide plate 9 is located at the top of the waste water area 302, and a guide hole 11 connected to the waste water area 302 and used to discharge the condensed waste water is also arranged there. The bottom end of the wastewater area 302 is connected to a wastewater collection tank 12 for collecting wastewater through a pipeline. The wastewater collection tank 12 is arranged on the left side outside the mother liquid distillation recovery tank 1; An evaporator 13 for evaporation and a stirrer 14 for stirring are provided in the evaporation zone 301 . The side end of the evaporation zone 301 is connected to the mother liquid input tank 4 through a pipeline, and the bottom end of the evaporation zone 301 is connected to the mother liquid output tank 2 through a pipeline.

[0014] The working principle and use process of this embodiment are as follows: Figure 1 It is shown that after the ethanol recovery system is assembled, it is installed as a whole in the equipment of the etherification process of pregnenylcarboxylic acid lactone. Its purpose is to recover the ethanol in the etherification process of pregnenylcarboxylic acid lactone, reduce the emission of hazardous waste, and solve the problem of increasing the difficulty of treatment due to the difficulty in recovering the ethanol in the etherification mother liquor of pregnenylcarboxylic acid lactone, which effectively reduces the production cost of pregnenylcarboxylic acid lactone and the burden on environmental protection, improves the added value of the finished product of pregnenylcarboxylic acid lactone, and ensures the product competitiveness of pregnenylcarboxylic acid lactone.

[0015] When it is necessary to recover the ethanol in the etherification process of pregnenyl carboxylic acid lactone, firstly, the etherification mother liquor of pregnenyl carboxylic acid lactone in the etherification process of pregnenyl carboxylic acid lactone is transported to the distillation tower 3 through the mother liquor input tank 4 by a liquid pump (the functions and structures of conventional equipment such as liquid pumps are well known in the art, and the connection settings are also well known common sense, so no further explanation is given here, and it is not shown in the drawings), and the etherification mother liquor of pregnenyl carboxylic acid lactone is heated and evaporated by the evaporator 13 and the stirrer 14 to form steam, and then the interior of the distillation tower 3 is evaporated by intermittent exhaust of the vacuum unit 8. A negative pressure environment is formed in the part, so that part of the steam is condensed into water first through the condenser 10 under the negative pressure state, and the water will slide down the guide plate 9 from the guide hole 11 to the wastewater area 302, and then be discharged into the wastewater collection tank 12 through the wastewater area 302. The other part of the steam passes through the spiral condenser 5 and is condensed into ethanol by using the temperature of the mother liquid input tank 4 itself and is discharged into the ethanol collection tank 6 to reduce the amount of hazardous waste. The ethanol collected in the ethanol collection tank 6 is further applied to the etherification process of pregnenyl carboxylic acid lactone to reduce the use of new ethanol, and then the ethanol collection tank 6, the ethanol in the distillation tower 3 is tested for moisture, and when the moisture content of the ethanol is ≧0.5%, the pregnant carboxylic acid lactone etherification mother liquor is continuously transported to the distillation tower 3 through the mother liquor input tank 4 to achieve the purpose of continuous recovery and treatment. At the same time, the transport speed and evaporation speed of the pregnant carboxylic acid lactone etherification mother liquor are controlled to maintain a balance between the two. Since the pregnant carboxylic acid lactone etherification mother liquor transported in the distillation tower 3 causes the liquid level to rise as the content increases, when the liquid level sensor 15 detects that the pregnant carboxylic acid lactone etherification mother liquor in the distillation tower 3 reaches the monitoring value, the transport of the pregnant carboxylic acid lactone etherification mother liquor is stopped. After the evaporator 13 in the distillation tower 3 is heated and evaporated for 4 to 5 minutes, the evaporator 13 and the stirrer 14 in the evaporation zone 301 are first closed (i.e., the heating system of the distillation tower 3 is closed), and then the pregnenyl carboxylic acid lactone etherification mother liquid in the distillation tower 3 is discharged all at once through the mother liquid output tank 2, and then the evaporator 13 and the stirrer 14 in the evaporation zone 301 are opened, and then the pregnenyl carboxylic acid lactone etherification mother liquid in the pregnenyl carboxylic acid lactone etherification process is transported to the distillation tower 3 through the mother liquid input tank 4 by a liquid pump, and the above steps are repeated until the production of pregnenyl carboxylic acid lactone is completed.

[0016] The original pregnenyl carboxylic acid lactone etherification process was renovated and the ethanol recovery system was installed. The moisture ratio of ethanol recovered from the pregnenyl carboxylic acid lactone etherification post was tested, and the ethanol recovery rate was able to reach the expected target: Technical indicators: After the pilot test, the water content of ethanol recovered from the etherification of pregnenyl carboxylic acid lactone is ≥ 0.5, which can be applied in the etherification reaction; Economic indicators: After the pilot test, the recovery rate of ethanol in the etherification of pregnenyl carboxylic acid lactone was 70%, which met the predetermined yield index; It can be seen that the ethanol recovery system not only reduces the amount of hazardous waste, but also reduces the use of new ethanol, effectively reducing production costs. Moreover, after a six-month pilot trial period, the yield and quality of the etherified product obtained by the ethanol recovery system for pregnenyl carboxylic acid lactone met the expected standards, laying a good foundation for the preparation of etherified products using etherified recovered ethanol in later products.

Claims

1. An ethanol recovery system for etherification of pregnenyl carboxylic acid lactone, comprising a mother liquor distillation recovery tank, characterized in that: A mother liquid output tank, a distillation tower and a mother liquid input tank are respectively arranged at the left, middle and right ends of the interior of the mother liquid distillation recovery tank. The distillation tower is connected with the mother liquid input tank and the mother liquid output tank through pipelines respectively. A spiral condenser is arranged inside the mother liquid input tank. One end of the spiral condenser penetrates a side wall of the mother liquid input tank and extends to the outside of the mother liquid input tank to be connected with an ethanol collection tank arranged on the right side of the outside of the mother liquid distillation recovery tank. The other end of the spiral condenser penetrates the other side wall of the mother liquid input tank and extends to the outside of the mother liquid input tank to be connected with the distillation tower.

2. The ethanol recovery system for etherification of pregnenolactone according to claim 1, characterized in that: The interior of the distillation tower is vertically provided with partitions and is divided into an evaporation zone and a wastewater zone by the partitions.

3. The ethanol recovery system for etherification of pregnenolactone according to claim 2, characterized in that: A liquid level sensor is arranged on the top of the partition.

4. The ethanol recovery system for etherification of pregnenolactone according to claim 2, characterized in that: The bottom end of the wastewater area is connected to a wastewater collection tank through a pipeline, and the wastewater collection tank is arranged on the left side outside the mother liquid distillation recovery tank.

5. The ethanol recovery system for etherification of pregnenolactone according to claim 4, characterized in that: A guide plate is obliquely arranged at the inner top of the distillation tower, and a condenser is arranged above the guide plate.

6. The ethanol recovery system for etherification of pregnenolactone according to claim 5, characterized in that: The highest point of the guide plate is located at the top of the evaporation zone, and the lowest point of the guide plate is located at the top of the wastewater zone, where a guide hole communicating with the wastewater zone is also arranged.

7. The ethanol recovery system for etherification of pregnenolactone according to claim 2, characterized in that: The side end of the evaporation zone is connected to the mother liquid input tank through a pipeline, and the bottom end of the evaporation zone is connected to the mother liquid output tank through a pipeline.

8. The ethanol recovery system for etherification of pregnenolactone according to claim 7, characterized in that: An evaporator and a stirrer are arranged in the evaporation zone.

9. The ethanol recovery system for etherification of pregnenolactone according to claim 1, characterized in that: A vacuum unit is fixed on the distillation tower.

10. A method for recovering ethanol from the etherification of pregnenyl carboxylic acid lactone, characterized in that: The ethanol recovery system for etherification of pregnenyl carboxylic acid lactone according to any one of claims 1 to 9 is used to recover ethanol in the etherification process of pregnenyl carboxylic acid lactone, and the specific steps are as follows: S1, transporting the etherified mother liquor of pregnenyl carboxylic acid lactone to a distillation tower through a liquid pump via a mother liquor input tank for negative pressure distillation treatment; S2, the steam generated in the negative pressure distillation process is first condensed by the condenser to form wastewater, which slides into the wastewater area through the guide hole of the guide plate and is discharged into the wastewater collection tank through the pipeline, and then condensed by the spiral condenser using the temperature of the mother liquid input tank to form ethanol, which is discharged into the ethanol collection tank; S3, testing the water content of the ethanol in the ethanol collection tank, and when the water content of the ethanol is ≧0.5%, continuously conveying the etherification mother liquor of pregnenyl carboxylic acid lactone for continuous recovery treatment; S4, after the distillation tower is heated and evaporated for 4 to 5 minutes, the evaporator and the agitator in the distillation tower are first closed, and then the etherification mother liquor of pregnenyl carboxylic acid lactone in the distillation tower is completely discharged through the mother liquor output tank at one time, and then the evaporator and the agitator in the distillation tower are opened to repeat S1 to S4.

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