Comprehensive utilization device and process for butanol-containing organic salt-containing wastewater produced as a by-product in the recovery process of acrylic acid and esters

Abstract

The present invention belongs to the technical field of organic wastewater treatment, and specifically relates to a device and process for the comprehensive utilization of organic salt-containing wastewater containing butanol, a by-product of the acrylic acid and ester recovery process. The present invention performs a preliminary separation of organic matter and salts through atmospheric distillation to form two components: butanol-containing wastewater and organic sodium salt. The butanol-containing wastewater is then separated through a rectification process to form a mixture of saturated water and butanol. The mixture is then subjected to a third separation using a ceramic membrane to form a high-content butanol. The organic sodium salt component is then melt-incinerated. The three-stage separation + incineration process, compared to the traditional direct incineration process, can recover high-value butyl ester and n-butyl ester materials, reducing material waste and pollutant emissions during the incineration process. By comprehensively utilizing and disposing of the organic salt-containing butanol wastewater produced as a by-product of the acrylic acid and ester recovery and comprehensive utilization device, the organic salt-containing butanol wastewater is recycled and rendered harmless.

Description

Technical Field

[0001] The invention belongs to the technical field of organic wastewater treatment, and in particular relates to a device and process for comprehensively utilizing organic salt-containing wastewater containing butanol produced as a by-product in the process of recovering acrylic acid and esters. Background Art

[0002] Wastewater containing organic sodium salts of butanol, a byproduct of the acrylic acid and ester recovery and comprehensive utilization unit, has been tested and found to contain approximately 20% salt (sodium sulfate 10%, sodium acrylate 5%, sodium p-toluenesulfonate 5%), 100,000 mg / L COD, 0.5% polymers, approximately 40% water, 25% butanol, and 15.5% organic esters. Currently, incineration is the primary method for disposing of wastewater containing organic sodium salts of butanol. However, direct incineration results in significant butanol loss, hindering resource recovery. Separation using the addition of extractants introduces other pollutants, leading to higher recovery costs. Another treatment method, centrifugation combined with filter cloth desalination, is also available. However, because the wastewater contains a large amount of low-flash organic matter, the centrifugation process can generate static electricity, potentially leading to safety hazards.

[0003] Therefore, exploring a comprehensive treatment process for butanol-containing organic salt-containing wastewater produced as a by-product of acrylic acid and ester recovery and comprehensive utilization equipment can not only achieve safe and efficient waste management, but also realize resource recycling. Summary of the Invention

[0004] In view of the above problems existing in the prior art, the object of the present invention is to provide a device and process for comprehensive utilization of organic salt-containing wastewater containing butanol produced as a by-product in the recovery process of acrylic acid and esters.

[0005] In order to solve the above problems, the technical solutions adopted by the present invention are as follows:

[0006] A device for comprehensively utilizing organic and salty butanol-containing wastewater produced as a by-product in the process of recovering acrylic acid and esters comprises a wastewater inlet pipe connected to a distillation device, a gas outlet of the distillation device connected to a butanol-containing wastewater storage tank via a cooling device, and a liquid outlet of the distillation device connected to a high-concentration organic salt storage tank; an outlet of the butanol-containing wastewater storage tank connected to a rectifying tower, a gas phase outlet of the rectifying tower connected to a phase separator via a heat exchange device, the phase separator connected to an exhaust pipe, a liquid outlet pipeline of the phase separator connected to the rectifying tower via a reflux pump, an outlet of the reflux pump further connected to a butanol-containing organic matter storage tank, the butanol-containing organic matter storage tank connected to an n-butanol storage tank and a process water storage tank via a membrane separation device; a liquid phase outlet of the rectifying tower connected to the butanol-containing wastewater storage tank, and the butanol-containing wastewater storage tank connected to a butyl ester storage tank via an overflow port.

[0007] Optionally, the butanol-containing wastewater storage tank is connected to an inhibitor inlet and an oxygen-depleted injection pipeline.

[0008] Optionally, a nitrogen inlet pipe is connected to the exhaust pipe, and an outlet of the exhaust pipe is connected to a tail gas incineration system.

[0009] Optionally, the membrane separation equipment adopts ceramic membrane separation technology.

[0010] Optionally, the cooling device includes a first circulating water heat exchanger and a first chilled water heat exchanger, and the gas outlet of the distillation equipment is connected to the first circulating water heat exchanger and the first chilled water heat exchanger in sequence and then connected to the butanol-containing wastewater storage tank; the heat exchange device includes a second circulating water heat exchanger and a second chilled water heat exchanger, and the gas phase outlet of the distillation tower is connected to the second circulating water heat exchanger and the second chilled water heat exchanger in sequence.

[0011] Optionally, a steam thermal oil heat exchanger is connected to the distillation tower.

[0012] Optionally, a first centrifugal pump is provided between the outlet of the butanol-containing wastewater storage tank and the distillation tower; and a second centrifugal pump is provided between the butanol-containing organic matter storage tank and the membrane separation equipment.

[0013] The process for comprehensive utilization of organic salt-containing wastewater containing butanol produced as a by-product during the acrylic acid and ester recovery process using the above-mentioned device comprises the following steps:

[0014] S1. Butanol-containing organic salt wastewater is distilled through a distillation device. The gas phase is condensed through a cooling device and then enters an alcohol-containing wastewater storage tank. Concentrated salt is formed at the bottom of the distillation device and regularly discharged to a high-concentration organic salt storage tank, and then sent to an incineration system for incineration;

[0015] S2. The liquid in the alcohol-containing wastewater storage tank is transported to a distillation tower via a centrifugal pump, wherein butanol and water are azeotropically discharged into a heat exchange device through a gas phase outlet and then condensed, part of which is returned to the distillation tower via a reflux pump, and part of which enters a butanol-containing organic matter storage tank; the high-boiling-point organic matter at the bottom of the distillation tower enters the butanol-containing wastewater storage tank again through a liquid phase outlet; the upper ester organic matter in the butanol-containing wastewater storage tank flows into the butyl ester storage tank through an overflow port;

[0016] S3. The material in the butanol-containing organic matter storage tank is separated into butanol and water through a membrane separation device, wherein the water enters the process water storage tank and is then recycled to the production device; the butanol enters the n-butanol storage tank.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention comprehensively utilizes and disposes of butanol-containing organic salt-containing wastewater produced as a by-product of an acrylic acid and ester recovery and comprehensive utilization device, achieving resource utilization and harmless disposal of the butanol-containing organic salt-containing wastewater. Organic matter and salt are initially separated by atmospheric distillation to form two components: butanol-containing wastewater and organic sodium salt. The butanol-containing wastewater is then separated through a rectification process to form a mixture of saturated water and butanol. The mixture is then separated a third time through a ceramic membrane to form a high-content butanol. The organic sodium salt component is then melt-incinerated. This three-stage separation + incineration process, compared to conventional direct incineration processes, can recover high-value butyl ester and n-butyl ester materials, reduce material waste, and reduce pollutant emissions during the incineration process. The device utilizes advanced membrane separation technology and a cascade heat exchange method, resulting in low overall energy consumption and long-term stable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of a comprehensive utilization device for butanol-containing organic salt-containing wastewater produced as a by-product in the acrylic acid and ester recovery process;

[0020] In the figure: 1. Wastewater inlet pipe; 2. Distillation equipment; 3. First circulating water heat exchanger; 4. First chilled water heat exchanger; 5. Butanol wastewater storage tank; 6. High-concentration organic salt storage tank; 7. Incinerator system; 8. First centrifugal pump; 9. Distillation tower; 10. Second circulating water heat exchanger; 11. Second chilled water heat exchanger; 12. Phase separator; 13. Nitrogen inlet pipe; 14. Tail gas incineration system; 15. Reflux pump; 16. Butanol organic matter storage tank; 17. Second centrifugal pump; 18. Membrane separation equipment; 19. n-butanol storage tank; 20. Process water storage tank; 21. Butyl ester storage tank; 22. Oxygen-depleted injection pipeline; 23. Steam thermal oil heat exchanger. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] like Figure 1 As shown, the following provides a technical solution:

[0023] A device for comprehensively utilizing organic salt-containing butanol wastewater produced as a by-product in the process of recovering acrylic acid and esters, comprising a wastewater inlet pipe 1 connected to a distillation device 2. Wastewater flows into the distillation device 2 through the wastewater inlet pipe 1 under the action of gravity. The gas outlet of the distillation device 2 is connected to a butanol-containing wastewater storage tank 5 after passing through a first circulating water heat exchanger 3 and a first chilled water heat exchanger 4 connected in sequence. The liquid outlet of the distillation device 2 is connected to a high-concentration organic salt storage tank 6 (organic sodium salt is concentrated to 50%), and then sent to an incinerator system. 7 is atomized and incinerated, and sodium sulfate is produced as a by-product during the incineration process, which is entrusted to a qualified unit for comprehensive utilization; the outlet of the butanol wastewater storage tank 5 is connected to a distillation tower 9 through a first centrifugal pump 8, and the gas phase outlet of the distillation tower 9 is connected to a phase separator 12 through a second circulating water heat exchanger 10 and a second chilled water heat exchanger 11 connected in sequence. The phase separator 12 is connected to an exhaust pipe, and the exhaust pipe is connected to a nitrogen inlet pipe 13. The outlet of the exhaust pipe is connected to an exhaust gas incineration system 14. The exhaust gas discharged by the phase separator 12 is inerted before being incinerated. The liquid outlet pipeline of the phase separator 12 is connected to the distillation tower 9 through a reflux pump 15. The outlet of the reflux pump 15 is also connected to a butanol organic matter storage tank 16. The butanol organic matter storage tank 16 is connected to a membrane separation device 18 through a second centrifugal pump 17. The membrane separation device 18 adopts advanced ceramic membrane separation technology. The membrane separation device 18 is provided with a n-butanol storage tank 19 and a process water storage tank 20; the liquid phase outlet of the distillation tower 9 is connected to the butanol-containing wastewater storage tank 5, and the butanol-containing wastewater storage tank 5 is connected to a butyl ester storage tank 21 through an overflow port.

[0024] The butanol-containing wastewater storage tank 5 is connected to the MEHQ and PTZ inhibitor inlets and is provided with an oxygen-depleted injection pipeline 22. By injecting oxygen-depleted (8±4%) and MEHQ+PTZ inhibitors into the butanol-containing wastewater to inhibit polymerization, the equipment has good stability and no system polymerization occurs.

[0025] The distillation tower 9 is connected to a steam-heat-oil heat exchanger 23, and the heat-conducting oil (250°C) and steam (0.5MPA) are circulated for heat exchange. In addition, circulating water (25°C) and cooling water (5°C) are set at the gas outlet of the distillation equipment 2 and the gas phase outlet of the distillation tower 9 for secondary circulation cooling, resulting in low comprehensive energy consumption.

[0026] A comprehensive utilization process for butanol-containing organic salt-containing wastewater produced as a by-product in the recovery process of acrylic acid and esters, comprising the following steps:

[0027] S1, the organic salt-containing wastewater containing butanol produced as a by-product in the acrylic acid and ester recovery process enters the distillation equipment 2 through the wastewater inlet pipe 1, is distilled by the distillation equipment 2, and the gas phase of the light component evaporates into the cooling device, and then condensed by the cooling device and flows into the alcohol-containing wastewater storage tank. Concentrated salt is formed at the bottom of the distillation equipment 2 and is regularly discharged to the high-concentration organic salt storage tank 6, and then sent to the incineration system for incineration;

[0028] S2, the liquid in the alcohol-containing wastewater storage tank is transported to the distillation tower 9 by a centrifugal pump for separation, wherein butanol and water are azeotropically produced and enter the heat exchange device through the gas phase outlet at the top of the tower and then condensed. After condensation, part of the liquid is returned to the top of the distillation tower 9 through the reflux pump 15, and part enters the butanol-containing organic matter storage tank 16; the high-boiling point organic matter at the bottom of the distillation tower 9 enters the butanol-containing wastewater storage tank 5 again through the liquid phase outlet; the upper ester organic matter in the butanol-containing wastewater storage tank 5 flows into the butyl ester storage tank 21 (butyl ester concentration content is more than 70%, butyl ester yield is 95%) through the overflow port, and then is reused to the production device. The tail gas generated after distillation enters the exhaust pipe through the phase separator 12, and is incinerated after being inerted with nitrogen;

[0029] S3. The material in the butanol-containing organic matter storage tank 16 is separated into butanol and water by a membrane separation device 18, wherein the water enters the process water storage tank 20, wherein the process water meets the quality requirements of recycled industrial water, COD <200 mg / L, and can be reused in the production process; butanol enters the n-butanol storage tank 19 (n-butanol concentration content is more than 80%, and n-butanol yield is 90%), and can be reused in the production process.

[0030] This device and process utilizes DCS automated control and quality control to reduce manual labor, ensuring stable material feed and operating conditions. It avoids the use of centrifugal and filter cloth desalination technology, resulting in increased safety, no system blockages, and long-term stable production. Furthermore, the device does not utilize extraction processes, eliminating the risk of new pollutants.

[0031] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A device for comprehensive utilization of organic salt-containing wastewater containing butanol produced as a by-product in the process of recovering acrylic acid and esters, characterized in that: The invention comprises a wastewater inlet pipe (1), the wastewater inlet pipe (1) is connected to a distillation device (2), the gas outlet of the distillation device (2) is connected to a butanol-containing wastewater storage tank (5) via a cooling device, and the liquid outlet of the distillation device (2) is connected to a high-concentration organic salt storage tank (6); the outlet of the butanol-containing wastewater storage tank (5) is connected to a distillation tower (9), the gas phase outlet of the distillation tower (9) is connected to a phase separator (12) via a heat exchange device, the phase separator (12) is connected to an exhaust pipe, and the phase separator ( The liquid outlet pipeline of the distillation tower (12) is connected to the distillation tower (9) via a reflux pump (15), and the outlet of the reflux pump (15) is further connected to a butanol-containing organic matter storage tank (16), and the butanol-containing organic matter storage tank (16) is connected to a n-butanol storage tank (19) and a process water storage tank (20) via a membrane separation device (18); the liquid phase outlet of the distillation tower (9) is connected to the butanol-containing wastewater storage tank (5), and the butanol-containing wastewater storage tank (5) is connected to a butyl ester storage tank (21) via an overflow port; The butanol-containing wastewater storage tank (5) is connected to an inhibitor inlet and an oxygen-depleted injection pipeline (22); The distillation tower (9) is connected to a steam-heat-conducting oil heat exchanger (23); The operation steps are: S1, butanol-containing organic salt-containing wastewater is distilled through a distillation device (2), and the gas phase is condensed through a cooling device and then enters an alcohol-containing wastewater storage tank. Concentrated salt is formed at the bottom of the distillation device (2), and is regularly discharged to a high-concentration organic salt storage tank (6), and then sent to an incineration system for incineration; S2, the liquid in the alcohol-containing wastewater storage tank is transported to the distillation tower (9) through a centrifugal pump, wherein butanol and water are azeotropically discharged into a heat exchange device through a gas phase outlet and then condensed, part of which is returned to the distillation tower (9) through a reflux pump (15), and part of which enters the butanol-containing organic matter storage tank (16); the high-boiling point organic matter at the bottom of the distillation tower (9) enters the butanol-containing wastewater storage tank (5) again through a liquid phase outlet; the upper ester organic matter in the butanol-containing wastewater storage tank (5) flows into the butyl ester storage tank (21) through an overflow port; S3. The material in the butanol-containing organic matter storage tank (16) is separated into butanol and water by a membrane separation device (18), wherein the water enters the process water storage tank (20) and is then recycled to the production device; the butanol enters the n-butanol storage tank (19).

2. The device for comprehensive utilization of organic salt-containing wastewater containing butanol produced as a by-product in the process of recovering acrylic acid and esters according to claim 1, characterized in that: The exhaust pipe is connected to a nitrogen inlet pipe (13), and the outlet of the exhaust pipe is connected to a tail gas incineration system (14).

3. The device for comprehensive utilization of organic salt-containing wastewater containing butanol produced as a by-product in the process of recovering acrylic acid and esters according to claim 1, characterized in that: The membrane separation device (18) adopts ceramic membrane separation technology.

4. The device for comprehensive utilization of organic salt-containing wastewater containing butanol produced as a by-product in the process of recovering acrylic acid and esters according to claim 1, characterized in that: The cooling device comprises a first circulating water heat exchanger (3) and a first chilled water heat exchanger (4); the gas outlet of the distillation equipment (2) is connected to the first circulating water heat exchanger (3) and the first chilled water heat exchanger (4) in sequence, and then connected to the butanol-containing wastewater storage tank (5); the heat exchange device comprises a second circulating water heat exchanger (10) and a second chilled water heat exchanger (11); the gas phase outlet of the distillation tower (9) is connected to the second circulating water heat exchanger (10) and the second chilled water heat exchanger (11) in sequence.

5. The device for comprehensive utilization of organic salt-containing wastewater containing butanol produced as a by-product in the process of recovering acrylic acid and esters according to claim 1, characterized in that: A first centrifugal pump (8) is provided between the outlet of the butanol-containing wastewater storage tank (5) and the distillation tower (9); and a second centrifugal pump (17) is provided between the butanol-containing organic matter storage tank (16) and the membrane separation device (18).

6. A process for comprehensive utilization of organic salt-containing wastewater containing butanol produced as a by-product in the process of recovering acrylic acid and esters using the device according to any one of claims 1 to 5, characterized in that: The steps include: S1, butanol-containing organic salt-containing wastewater is distilled through a distillation device (2), and the gas phase is condensed through a cooling device and then enters an alcohol-containing wastewater storage tank. Concentrated salt is formed at the bottom of the distillation device (2), and is regularly discharged to a high-concentration organic salt storage tank (6), and then sent to an incineration system for incineration; S2, the liquid in the alcohol-containing wastewater storage tank is transported to the distillation tower (9) through a centrifugal pump, wherein butanol and water are azeotropically discharged into a heat exchange device through a gas phase outlet and then condensed, part of which is returned to the distillation tower (9) through a reflux pump (15), and part of which enters the butanol-containing organic matter storage tank (16); the high-boiling point organic matter at the bottom of the distillation tower (9) enters the butanol-containing wastewater storage tank (5) again through a liquid phase outlet; the upper ester organic matter in the butanol-containing wastewater storage tank (5) flows into the butyl ester storage tank (21) through an overflow port; S3. The material in the butanol-containing organic matter storage tank (16) is separated into butanol and water by a membrane separation device (18), wherein the water enters the process water storage tank (20) and is then recycled to the production device; the butanol enters the n-butanol storage tank (19).

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