Comprehensive recycling device for acrylic acid wastewater

Abstract

The utility model relates to the technical field of acrylic acid wastewater treatment, and particularly discloses a comprehensive recycling device for acrylic acid wastewater. The utility model provides a device for continuously treating generated acrylic acid wastewater, the device comprises an extraction tower, an extraction agent recovery rectifying tower, a light component removal rectifying tower, a heavy component removal rectifying tower and other equipment, acrylic acid and wastewater in the acrylic acid wastewater can be recovered at the same time by utilizing the device system, and more than 99 wt% of acrylic acid product and more than 99 wt% of wastewater are obtained after refining; the recovered acrylic acid can be sold as a product, and the recovered wastewater can be recycled for multiple times and reused in the production process of acrolein, acrylic acid and derivatives thereof, so that the economic benefit is greatly improved; tail gas meets the emission standard, and the emission amount of three wastes is small.

Description

Technical Field

[0001] The present application relates to the technical field of acrylic acid wastewater treatment, and in particular to a comprehensive recycling and utilization device for acrylic acid wastewater. Background Art

[0002] Acrylic acid wastewater primarily originates from the production of acrylic acid and its derivatives. The separation and purification of aqueous acrylic acid solutions primarily involves solvent extraction and azeotropic dehydration. Industrial acrolein production generates wastewater containing approximately 10% acrylic acid, requiring complex treatment. Currently, the treatment of acrylic acid wastewater in industrial production faces two technical challenges:

[0003] On the one hand, a large amount of acrylic acid wastewater is generally generated in the production process of acrolein, acrylic acid and its derivatives. The existing technology generally undergoes a series of treatment processes such as neutralization, precipitation, filtration, biochemical treatment, and incineration. The process is complex, the cost is high, and the environmental cost is high.

[0004] On the other hand, the acrylic acid contained in the acrylic acid wastewater is not fully recycled, resulting in low economic efficiency and low acrylic acid utilization rate.

[0005] In view of the problem that a large amount of acrylic acid wastewater is generated in the existing industrial production of acrolein, acrylic acid and their derivatives, there is an urgent need for a new treatment device that can efficiently recover acrylic acid with low energy consumption and low cost to recycle and treat acrylic acid wastewater. Utility Model Content

[0006] The present application provides a comprehensive recycling and utilization device for acrylic acid wastewater to solve the problems of complex process, high cost, high environmental protection cost, low economy and low utilization rate in the existing acrylic acid wastewater treatment process.

[0007] In order to solve the above technical problems or at least partially solve the above technical problems, the present application provides a comprehensive recycling and utilization device for acrylic acid wastewater, comprising:

[0008] Extraction tower, extractant recovery distillation tower, light removal distillation tower and heavy removal distillation tower;

[0009] The extraction tower is provided with an acrylic acid wastewater feed port and an extractant feed port for feeding extraction, and its organic phase discharge port is connected to the organic phase feed port of the extractant recovery distillation tower through a pipeline;

[0010] The bottom liquid discharge port of the extractant recovery distillation tower is connected to the bottom liquid feed port of the light removal distillation tower through a pipeline;

[0011] The bottom liquid discharge port of the light removal distillation tower is connected to the bottom liquid feed port of the heavy removal distillation tower through a pipeline; a light component discharge port is set at the top of the heavy removal distillation tower, and the light component can be recovered as acrylic acid after condensation.

[0012] Optionally, the device described in this application includes:

[0013] Acrylic acid wastewater buffer tank, extractant buffer tank, extraction tower, extractant recovery distillation tower, first condenser, first reflux tank, light removal distillation tower, second condenser, second reflux tank, heavy removal distillation tower, third condenser and third reflux tank;

[0014] The discharge port of the acrylic acid wastewater buffer tank is connected to the acrylic acid wastewater feed port provided in the extraction tower through a pipeline, and the discharge port of the extractant buffer tank is connected to the extractant feed port provided in the extraction tower through a pipeline;

[0015] The organic phase discharge port of the extraction tower is connected to the organic phase feed port of the extractant recovery distillation tower through a pipeline;

[0016] The light component discharge port of the top of the extractant recovery distillation tower is connected to the feed port of the first condenser, and the discharge port of the first condenser is connected to the feed port of the first reflux tank through pipelines; the discharge port of the first reflux tank is connected to the condensate feed port of the extractant recovery distillation tower and the feed port of the extractant buffer tank through pipelines; the bottom liquid discharge port of the extractant recovery distillation tower is connected to the bottom liquid feed port of the light component removal distillation tower through pipelines;

[0017] The light component discharge port of the tower top of the de-light fractionation tower is connected to the feed port of the second condenser, and the discharge port of the second condenser is connected to the feed port of the second reflux tank through pipelines; the discharge port of the second reflux tank is connected to the condensate feed port of the de-light fractionation tower and the organic phase feed port of the extractant recovery distillation tower through pipelines; the bottom liquid discharge port of the de-light fractionation tower is connected to the bottom liquid feed port of the de-heavy fractionation tower through pipelines;

[0018] The light component discharge port at the top of the heavy-removal distillation tower is connected to the feed port of the third condenser, and the discharge port of the third condenser is connected to the feed port of the third reflux tank through pipelines respectively; the discharge port of the third reflux tank is connected to the condensate feed port of the heavy-removal distillation tower through a pipeline, and the discharge port of the acrylic acid product is provided on the pipeline; the heavy-removal distillation tower is provided with a bottom liquid discharge port.

[0019] Optionally, the extraction tower is a countercurrent extraction tower, and the acrylic acid wastewater feed inlet and the extractant feed inlet of the extraction tower are respectively located at two ends of the extraction tower.

[0020] Optionally, an organic phase pump is provided on a pipeline connecting the organic phase discharge port of the extraction tower and the organic phase feed port of the extractant recovery distillation tower.

[0021] Optionally, the organic phase feed port of the extractant recovery distillation tower, the bottom liquid feed port of the light removal distillation tower, and the bottom liquid feed port of the heavy removal distillation tower are all arranged in the middle of the distillation tower; the bottom liquid discharge port of each distillation tower is arranged at the lower part of the distillation tower, and the condensate feed port of each distillation tower is arranged at the upper part of the distillation tower.

[0022] Optionally, the device described in the present application further comprises: a first reboiler, a second reboiler and a third reboiler;

[0023] The bottom liquid discharge port of the extractant recovery distillation tower is connected to the bottom liquid feed port of the first reboiler through a pipeline, and the bottom liquid discharge port of the first reboiler is connected to the bottom liquid feed port of the extractant recovery distillation tower through a pipeline;

[0024] The bottom liquid discharge port of the de-light fractionation tower is connected to the bottom liquid feed port of the second reboiler through a pipeline, and the bottom liquid discharge port of the second reboiler is connected to the bottom liquid feed port of the de-light fractionation tower through a pipeline;

[0025] The bottom liquid discharge port of the heavy-removal distillation tower is connected to the bottom liquid feed port of the third reboiler through a pipeline, and the bottom liquid discharge port of the third reboiler is connected to the bottom liquid feed port of the heavy-removal distillation tower through a pipeline.

[0026] Optionally, the device described in the present application further comprises: a water phase azeotropic distillation tower, a fourth condenser and a fourth reflux tank;

[0027] The water phase discharge port of the extraction tower is connected to the water phase feed port of the water phase azeotropic distillation tower through a pipeline;

[0028] The top azeotropic discharge port of the water-phase azeotropic distillation tower is connected to the feed port of the fourth condenser, and the discharge port of the fourth condenser is connected to the feed port of the fourth reflux tank through pipelines; the discharge port of the fourth reflux tank is connected to the condensate feed port of the water-phase azeotropic distillation tower and the feed port of the acrylic acid wastewater buffer tank through pipelines; the water-phase azeotropic distillation tower is provided with a bottom liquid discharge port.

[0029] Further optionally, a water phase pump is provided on the pipeline connecting the water phase discharge port of the extraction tower and the water phase feed port of the water phase azeotropic distillation tower.

[0030] Further optionally, it further comprises: a fourth reboiler; the tower bottom liquid discharge port of the water phase azeotropic distillation tower is connected to the tower bottom liquid feed port of the fourth reboiler through a pipeline, and the tower bottom liquid discharge port of the fourth reboiler is connected to the tower bottom liquid feed port of the water phase azeotropic distillation tower through a pipeline

[0031] Further optionally, the water phase feed port of the water phase azeotropic distillation tower is arranged in the middle of the distillation tower, and the bottom liquid discharge port of the water phase azeotropic distillation tower is arranged in the lower part of the distillation tower.

[0032] Optionally, valves, fluid pumps and other equipment may be installed as needed on each pipeline or pipeline bifurcation of the device described in the present application.

[0033] The present application provides a device for continuously treating generated acrylic acid wastewater, comprising an extraction tower, an extractant recovery distillation tower, a light-removal distillation tower, a heavy-removal distillation tower, and other equipment. The device system described in the present application can simultaneously recover acrylic acid and wastewater from the acrylic acid wastewater, and after refining, obtain an acrylic acid product of more than 99 wt% and wastewater of more than 99 wt%. The recovered acrylic acid can be sold as a product, and the recovered wastewater can be recycled multiple times and reused in the production process of acrolein, acrylic acid, and their derivatives, thereby greatly improving economic benefits. The tail gas meets emission standards, and the discharge of the three wastes is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present invention, and together with the description, serve to explain the principles of the present invention.

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0036] Figure 1 Shown is a schematic structural diagram of the device described in Example 1 of the present application;

[0037] Figure 2 Shown is a schematic structural diagram of the device described in Example 2 of the present application;

[0038] Figure 3 The figure shows a schematic diagram of the structure of the device described in Example 3 of the present application; reference numerals:

[0039] E-1: Acrylic acid wastewater buffer tank; E-2: Extractant buffer tank; E-3: Extraction tower; E-4: Organic phase pump; E-5: Extractant recovery distillation tower; E-6: First condenser; E-7: First reflux tank; E-8: Light removal distillation tower; E-9: Second condenser; E-10: Second reflux tank; E-11: Heavy removal distillation tower; E-12: Third condenser; E-13: Third reflux tank; E-14: First reboiler; E-15: Second reboiler; E-16: Third reboiler; E-17: Water phase pump; E-18: Water phase azeotropic distillation tower; E-19: Fourth condenser; E-20: Fourth reflux tank; E-21: Fourth reboiler. DETAILED DESCRIPTION

[0040] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0041] It should be noted that, in the description of the present invention, the terms "transverse", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the pavement structure referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as a limitation on the present invention.

[0042] Example 1:

[0043] Figure 1 This is a schematic diagram of the structure of a comprehensive recycling and utilization device for acrylic acid wastewater provided in this application. The device of this application includes:

[0044] Countercurrent extraction tower E-3, extractant recovery distillation tower E-5, light removal distillation tower E-8, and heavy removal distillation tower E-11;

[0045] The countercurrent extraction tower E-3 is provided with an acrylic acid wastewater feed port and an extractant feed port for feeding extraction, and its organic phase discharge port is connected to the organic phase feed port of the extractant recovery distillation tower E-5 through a pipeline;

[0046] The bottom liquid discharge port of the extractant recovery distillation tower E-5 is connected to the bottom liquid feed port of the light removal distillation tower E-8 through a pipeline;

[0047] The bottom liquid discharge port of the light removal distillation tower E-8 is connected to the bottom liquid feed port of the heavy removal distillation tower E-11 through a pipeline; a light component discharge port is set at the top of the heavy removal distillation tower E-11, and the light component can be recovered as acrylic acid after condensation.

[0048] Example 2:

[0049] Figure 2 This is a schematic diagram of the structure of a comprehensive recycling and utilization device for acrylic acid wastewater provided in this application. The device of this application includes:

[0050] Acrylic acid wastewater buffer tank E-1, extractant buffer tank E-2, countercurrent extraction column E-3, organic phase pump E-4, extractant recovery distillation column E-5, first condenser E-6, first reflux tank E-7, light removal distillation column E-8, second condenser E-9, second reflux tank E-10, heavy removal distillation column E-11, third condenser E-12, and third reflux tank E-13; first reboiler E-14; second reboiler E-15; and third reboiler E-16.

[0051] The discharge port of the acrylic acid wastewater buffer tank E-1 is connected to the wastewater feed port of the countercurrent extraction tower E-3 via a pipeline, and the discharge port of the extractant buffer tank E-2 is connected to the extractant feed port of the extraction tower E-3 via a pipeline; the wastewater feed port and the extractant feed port of the countercurrent extraction tower E-3 are located at the upper and lower ends of the countercurrent extraction tower E-3, respectively;

[0052] The organic phase discharge port of the countercurrent extraction tower E-3 (the upper layer is the organic phase, the discharge port is at the upper part of the tower) is connected to the organic phase feed port of the extractant recovery distillation tower E-5 through a pipeline, and an organic phase pump E-4 is installed on the pipeline;

[0053] The light component discharge port at the top of the extractant recovery distillation tower E-5 is connected to the feed port of the first condenser E-6, and the discharge port of the first condenser E-6 is connected to the feed port of the first reflux tank E-7 through pipelines; the discharge port of the first reflux tank E-7 is connected to the condensate feed port of the extractant recovery distillation tower E-5 and the feed port of the extractant buffer tank E-2 through pipelines; the bottom liquid discharge port of the extractant recovery distillation tower E-5 is connected to the bottom liquid feed port of the light removal distillation tower E-8 and the bottom liquid feed port of the first reboiler E-14 through pipelines; the bottom liquid discharge port of the first reboiler E-14 is connected to the bottom liquid feed port of the extractant recovery distillation tower E-5 through a pipeline;

[0054] The light component discharge port of the top of the de-light fractionation tower E-8 is connected to the feed port of the second condenser E-9, and the discharge port of the second condenser E-9 is connected to the feed port of the second reflux tank E-10 through pipelines; the discharge port of the second reflux tank E-10 is connected to the condensate feed port of the de-light fractionation tower E-8 and the organic phase feed port of the extractant recovery distillation tower E-5 through pipelines; the bottom liquid discharge port of the de-light fractionation tower E-8 is connected to the bottom liquid feed port of the de-heavy fractionation tower E-11 and the bottom liquid feed port of the second reboiler E-15 through pipelines; the bottom liquid discharge port of the second reboiler E-15 is connected to the bottom liquid feed port of the de-light fractionation tower E-8 through pipelines;

[0055] The light component discharge port at the top of the weight-removal distillation tower E-11 is connected to the feed port of the third condenser E-12, and the discharge port of the third condenser E-12 is connected to the feed port of the third reflux tank E-13 via pipelines, respectively. The discharge port of the third reflux tank E-13 is connected to the condensate feed port of the weight-removal distillation tower E-11 via a pipeline, and the pipeline is provided with a discharge port for an acrylic acid product for producing the acrylic acid product. The weight-removal distillation tower E-11 is provided with a bottom liquid discharge port, which is used to discharge waste liquid on the one hand and is connected to the bottom liquid feed port of the third reboiler E-16 via a pipeline on the other hand. The bottom liquid discharge port of the third reboiler E-16 is connected to the bottom liquid feed port of the weight-removal distillation tower E-11 via a pipeline.

[0056] The organic phase feed port of the extractant recovery distillation tower E-5, the bottom liquid feed port of the light removal distillation tower E-8, and the bottom liquid feed port of the heavy removal distillation tower E-11 are all located in the middle of the distillation tower; the bottom liquid discharge port of each distillation tower is located at the lower position of the distillation tower, and the condensate feed port of each distillation tower is located at the upper position of the distillation tower.

[0057] During the use of the device, the liquid from the acrylic acid wastewater buffer tank E-1 and the extractant from the extractant buffer tank E-2 simultaneously flow countercurrently into the countercurrent extraction tower E-3, and are extracted and separated to obtain an aqueous phase and an organic phase;

[0058] The organic phase is pumped via organic phase pump E-4 to the middle section of extractant recovery distillation column E-5. The operating pressure at the top of extractant recovery distillation column E-5 is approximately 100 kPa A, and the bottom temperature is approximately 140°C. A portion of the bottoms liquid from extractant recovery distillation column E-5 is pumped by a bottoms circulation pump to the first reboiler E-14 for steam heating before returning to the bottom. A portion of the product is withdrawn, and the level is adjusted by a level-controlled flow control valve before being transferred to light fractionation column E-8. The light components overhead from extractant recovery distillation column E-5 are condensed in the first condenser E-6. The condensate is then transferred to the first reflux drum E-7 via a head pressure differential. Non-condensable steam can be sent to the tail gas treatment unit at the boundary. A portion of the condensate re-enters the extractant recovery distillation column E-5 from the upper section of the column via a flow control valve. The remaining portion is withdrawn via level-controlled flow control in the first reflux drum E-7 and circulated to the extractant buffer tank E-2.

[0059] The bottoms liquid from the extractant recovery distillation column E-5 is pumped to the middle section of the de-light fractionation column E-8. The operating pressure at the top of the de-light fractionation column E-8 is approximately 100 kPa A, and the bottom temperature is approximately 143°C. A portion of the bottoms liquid is pumped from the bottoms to the second reboiler E-15 for steam heating before returning to the bottoms. A portion of the product is withdrawn and level-controlled by a cascade flow control valve before being transferred to the de-heavy fractionation column E-11. The light components overhead from the de-light fractionation column E-8 are condensed in the second condenser E-9. The condensate is then transferred to the second reflux drum E-10 via a head pressure differential. The non-condensable steam is then sent to the tail gas treatment unit at the boundary. A portion of the condensate re-enters the de-light fractionation column E-8 from the upper section via a flow control valve. The remaining portion is withdrawn through level control in the second reflux drum E-10 and circulated to the extractant recovery column E-5.

[0060] The bottoms liquid from the E-8 de-light fractionation column is pumped to the middle section of the E-11 de-heavy fractionation column. The E-11 overhead operating pressure is approximately 100 kPa A, and the bottom operating temperature is approximately 162°C. A portion of the bottoms liquid is pumped back to the third reboiler E-16 for steam heating before returning to the bottom. A portion of the product is removed and the level is adjusted by a cascade flow control valve before being discarded as waste liquid (polymer produced by acrylic acid distillation). The light components overhead from the E-11 de-light fractionation column are condensed in the third condenser E-12. The condensate is then directed to the third reflux drum E-13 using a head pressure differential. The non-condensable steam is then sent to the off-gas treatment unit in the off-gas degassing area. A portion of the condensate re-enters the E-11 de-light fractionation column from the upper section via a flow control valve. The remaining portion is removed by level control in the third reflux drum E-13 to remove the acrylic acid product.

[0061] Example 3:

[0062] Figure 3 This is a schematic diagram of the structure of a comprehensive recycling and utilization device for acrylic acid wastewater provided in this application. Based on the device structure of Example 2, the device and connection relationship of this embodiment also include the following:

[0063] Water phase pump E-17, water phase azeotropic distillation column E-18, fourth condenser E-19, fourth reflux tank E-20, fourth reboiler E-21;

[0064] The aqueous phase discharge port of the countercurrent extraction tower E-3 in Example 1 is connected to the aqueous phase feed port of the aqueous phase azeotropic distillation tower E-18 via a pipeline, and an aqueous phase pump E-17 is provided on the pipeline;

[0065] The top azeotropic discharge port of the aqueous azeotropic distillation tower E-18 is connected to the feed port of the fourth condenser E-19, and the discharge port of the fourth condenser E-19 is connected to the feed port of the fourth reflux tank E-20 through pipelines; the discharge port of the fourth reflux tank E-20 is connected to the condensate feed port of the aqueous azeotropic distillation tower E-18 and the feed port of the acrylic acid wastewater buffer tank E-1 in Example 1 through pipelines; the aqueous azeotropic distillation tower E-18 is provided with a bottom liquid discharge port, which is used to discharge wastewater on the one hand and is connected to the bottom liquid feed port of the fourth reboiler E-21 through a pipeline on the other hand. The bottom liquid discharge port of the fourth reboiler E-21 is connected to the bottom liquid feed port of the aqueous azeotropic distillation tower E-18 through a pipeline.

[0066] The water phase feed port of the water phase azeotropic distillation tower E-18 is set at the middle position of the distillation tower, and the bottom liquid discharge port is set at the lower position of the distillation tower.

[0067] During operation, the aqueous phase from countercurrent extraction tower E-3 enters the middle portion of aqueous azeotropic distillation tower E-18. The operating pressure at the top of E-18 is approximately 100 kPa A, and the bottom temperature is approximately 100°C. A portion of the bottom liquid from E-18 is thermosiphoned to the fourth reboiler E-21 for steam heating before returning to the bottom. A portion of the wastewater is removed, adjusted in level by a cascade flow control valve, and then transferred to an off-site wastewater tank. (The wastewater is primarily water, with a mass fraction of ≥99%, and can be recycled for use in other acrylic acid production processes.) The azeotropic material at the top of the water-phase azeotropic distillation tower E-18 is condensed in the fourth condenser E-19, and the condensate flows to the fourth reflux tank E-20 by potential difference, and the non-condensable steam is sent to the boundary area to remove the tail gas treatment device. Part of the condensate re-enters the water-phase azeotropic distillation tower E-18 from the upper area of ​​the tower through the flow regulating valve, and the other part is withdrawn to the acrylic acid wastewater buffer tank E-1 for circulation through the liquid level control of the fourth reflux tank E-20.

[0068] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0069] The foregoing description is intended only to provide specific embodiments of the present invention, intended to enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but rather to be construed in the broadest manner consistent with the principles and novel features claimed herein.

Claims

1. A comprehensive recycling and utilization device for acrylic acid wastewater, characterized in that: include: Extraction tower, extractant recovery distillation tower, light removal distillation tower and heavy removal distillation tower; The extraction tower is provided with an acrylic acid wastewater feed port and an extractant feed port for feeding extraction, and its organic phase discharge port is connected to the organic phase feed port of the extractant recovery distillation tower through a pipeline; The bottom liquid discharge port of the extractant recovery distillation tower is connected to the bottom liquid feed port of the light removal distillation tower through a pipeline; The bottom liquid discharge port of the light removal distillation tower is connected to the bottom liquid feed port of the heavy removal distillation tower through a pipeline; a light component discharge port is set at the top of the heavy removal distillation tower, and the light component can be recovered as acrylic acid after condensation.

2. The device according to claim 1, characterized in that include: Acrylic acid wastewater buffer tank, extractant buffer tank, extraction tower, extractant recovery distillation tower, first condenser, first reflux tank, light removal distillation tower, second condenser, second reflux tank, heavy removal distillation tower, third condenser and third reflux tank; The discharge port of the acrylic acid wastewater buffer tank is connected to the acrylic acid wastewater feed port provided in the extraction tower through a pipeline, and the discharge port of the extractant buffer tank is connected to the extractant feed port provided in the extraction tower through a pipeline; The organic phase discharge port of the extraction tower is connected to the organic phase feed port of the extractant recovery distillation tower through a pipeline; The light component discharge port of the top of the extractant recovery distillation tower is connected to the feed port of the first condenser, and the discharge port of the first condenser is connected to the feed port of the first reflux tank through pipelines; the discharge port of the first reflux tank is connected to the condensate feed port of the extractant recovery distillation tower and the feed port of the extractant buffer tank through pipelines; the bottom liquid discharge port of the extractant recovery distillation tower is connected to the bottom liquid feed port of the light component removal distillation tower through pipelines; The light component discharge port of the tower top of the de-light fractionation tower is connected to the feed port of the second condenser, and the discharge port of the second condenser is connected to the feed port of the second reflux tank through pipelines; the discharge port of the second reflux tank is connected to the condensate feed port of the de-light fractionation tower and the organic phase feed port of the extractant recovery distillation tower through pipelines; the bottom liquid discharge port of the de-light fractionation tower is connected to the bottom liquid feed port of the de-heavy fractionation tower through pipelines; The light component discharge port at the top of the heavy-removal distillation tower is connected to the feed port of the third condenser, and the discharge port of the third condenser is connected to the feed port of the third reflux tank through pipelines respectively; the discharge port of the third reflux tank is connected to the condensate feed port of the heavy-removal distillation tower through a pipeline, and the discharge port of the acrylic acid product is provided on the pipeline; the heavy-removal distillation tower is provided with a bottom liquid discharge port.

3. The device according to claim 1 or 2, characterized in that The extraction tower is a countercurrent extraction tower, and the acrylic acid wastewater feed inlet and the extractant feed inlet of the extraction tower are respectively located at two ends of the extraction tower.

4. The device according to claim 1 or 2, characterized in that An organic phase pump is provided on a pipeline connecting the organic phase discharge port of the extraction tower and the organic phase feed port of the extractant recovery distillation tower.

5. The device according to claim 1 or 2, characterized in that The organic phase feed port of the extractant recovery distillation tower, the bottom liquid feed port of the light removal distillation tower, and the bottom liquid feed port of the heavy removal distillation tower are all arranged in the middle of the distillation tower; the bottom liquid discharge port of each distillation tower is arranged at the lower part of the distillation tower, and the condensate feed port of each distillation tower is arranged at the upper part of the distillation tower.

6. The device according to claim 1 or 2, characterized in that Also includes: a first reboiler, a second reboiler, and a third reboiler; The bottom liquid discharge port of the extractant recovery distillation tower is connected to the bottom liquid feed port of the first reboiler through a pipeline, and the bottom liquid discharge port of the first reboiler is connected to the bottom liquid feed port of the extractant recovery distillation tower through a pipeline; The bottom liquid discharge port of the de-light fractionation tower is connected to the bottom liquid feed port of the second reboiler through a pipeline, and the bottom liquid discharge port of the second reboiler is connected to the bottom liquid feed port of the de-light fractionation tower through a pipeline; The bottom liquid discharge port of the heavy-removal distillation tower is connected to the bottom liquid feed port of the third reboiler through a pipeline, and the bottom liquid discharge port of the third reboiler is connected to the bottom liquid feed port of the heavy-removal distillation tower through a pipeline.

7. The device according to claim 1 or 2, characterized in that Also includes: a water phase azeotropic distillation tower, a fourth condenser and a fourth reflux tank; The water phase discharge port of the extraction tower is connected to the water phase feed port of the water phase azeotropic distillation tower through a pipeline; The top azeotropic discharge port of the water-phase azeotropic distillation tower is connected to the feed port of the fourth condenser, and the discharge port of the fourth condenser is connected to the feed port of the fourth reflux tank through pipelines; the discharge port of the fourth reflux tank is connected to the condensate feed port of the water-phase azeotropic distillation tower and the feed port of the acrylic acid wastewater buffer tank through pipelines; the water-phase azeotropic distillation tower is provided with a bottom liquid discharge port.

8. The device according to claim 7, characterized in that A water phase pump is provided on a pipeline connecting the water phase discharge port of the extraction tower and the water phase feed port of the water phase azeotropic distillation tower.

9. The device according to claim 7, characterized in that Also includes: fourth reboiler; The bottom liquid discharge port of the water phase azeotropic distillation tower is connected to the bottom liquid feed port of the fourth reboiler through a pipeline, and the bottom liquid discharge port of the fourth reboiler is connected to the bottom liquid feed port of the water phase azeotropic distillation tower through a pipeline.

10. The device according to claim 7, characterized in that The water phase feed port of the water phase azeotropic distillation tower is arranged in the middle of the distillation tower, and the tower bottom liquid discharge port of the water phase azeotropic distillation tower is arranged in the lower part of the distillation tower.

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