Waste liquid treatment system

Abstract

The utility model discloses a waste liquid treatment system. According to the device, a polymerization inhibitor 701 is added into waste PGMEA diluent raw materials according to a certain proportion to be fully mixed, and PGMEA products are recycled under the conditions of pressure reduction and specific temperature, so that the problem that a heating tube bundle and a heating kettle or a reboiler wall are adhered due to polymerization of photoresist caused by continuous heating and concentration at present is solved. Compared with the existing cleaning mode of deslagging the heating tube bundle after heating, such as beating, high-pressure equipment cleaning, incineration and the like, the heating process is completed, the heating tube bundle does not need to be detached, the production halt time, the labor intensity of workers and the energy consumption caused by the blockage of the heating tube bundle are greatly reduced, and the production efficiency is improved. And the continuous production time is prolonged. Compared with other polymerization inhibitors, the polymerization inhibitor 701 is good in polymerization inhibition effect, small in addition amount, low in environmental pollution and low in market price. The device can solve the problem of blockage of the waste diluent heating tube bundle, and has the characteristics of greenness, high efficiency and low cost.

Description

Technical Field

[0001] The utility model belongs to the field of waste utilization, and in particular relates to a PGMEA waste liquid treatment system. Background Art

[0002] Photoresist is an important consumable in the liquid crystal display industry, which can etch the required pattern on the surface of the substrate. According to the chemical reaction mechanism and the principle of development, photoresist can be divided into two categories: negative photoresist and positive photoresist. Negative photoresist forms insoluble substances after light exposure, and positive photoresist becomes soluble substances after light exposure. Photoresist is a light-sensitive mixed liquid composed of three main components: photosensitive resin, photosensitizer and solvent. Among them, photosensitive resin is an adhesive that gives photoresist mechanical and chemical properties, such as adhesion, film thickness, thermal stability, etc.; photosensitizer can make photoresist photochemically react to light energy; solvent can keep photoresist in liquid state, so that it has good fluidity. The resin of negative photoresist is polyisoprene, a natural rubber, and the solvent is xylene; photosensitizer is a photosensitizer that releases nitrogen after exposure, and the free radicals generated form cross-links between rubber molecules, making it insoluble in the developer. Negative photoresist swells in the exposed area due to the solvent. When exposed, the photoresist easily reacts with nitrogen and inhibits cross-linking. The resin of positive photoresist is a linear phenolic resin, which provides the photoresist with adhesion and chemical corrosion resistance. When there is no dissolution inhibitor, the linear phenolic resin will dissolve in the developer; the photosensitizer is a photosensitive compound, the most common of which is diazonaphthoquinone (DNQ). Before exposure, DNQ is a strong dissolution inhibitor that reduces the dissolution rate of the resin. After ultraviolet exposure, DNQ chemically decomposes in the photoresist and becomes a solubility enhancer, which greatly increases the solubility in the developer.

[0003] PGMEA (Propylene glycol methyl ether acetate) waste liquid mainly refers to the waste liquid generated when propylene glycol methyl ether acetate diluent is used to treat photoresist. There are two main reasons for the generation of waste liquid: First, during the photoresist coating process, with the high-speed rotation of the silicon wafer, the excess photoresist will be thrown to the edge of the container outside the silicon wafer, and the nozzle will also have residual photoresist. In order to ensure the accuracy of circuit etching, the silicon wafer coating must be kept uniform and clean. Therefore, before coating, the nozzle and the edge of the container need to be cleaned with propylene glycol methyl ether acetate diluent, and after cleaning, it becomes PGMEA waste liquid; second, PGMEA waste liquid is generated during the glue washing process. Propylene glycol methyl ether acetate diluent is used to clean the soluble photoresist part after light exposure and becomes PGMEA waste liquid. The above analysis explains the process of PGMEA diluent becoming waste diluent due to cleaning photoresist, the types, differences, and components of photoresist. Whether it is positive photoresist or negative photoresist, PGMEA diluent washes away the easily soluble photoresist part, but can also wash away a very small part of the insoluble photoresist part, that is, the waste PGMEA diluent is mainly a mixed solvent containing mostly monomers and a small amount of intermediates and polymers.

[0004] During the recycling process of waste PGMEA diluent, the monomers gradually polymerize as it is heated and concentrated. Due to the difference in the characteristics of positive and negative photoresists, the diluent waste liquid containing negative photoresist is generally red. The concentrated negative photoresist still has good fluidity and is easy to be discharged from the heating kettle or reboiler, so it does not have a major impact; the diluent containing positive photoresist is black. As it is heated and concentrated to less than 35w / w% of the raw material amount, the high temperature causes the linear phenolic resin to polymerize and solidify, and adhere to the heating tube or reboiler, seriously affecting the heating efficiency, production efficiency and operating intensity. Take 10m 3 Taking a heating kettle or reboiler with a capacity of 200 tons as an example, every time the heating kettle or reboiler processes 35 tons of waste diluent, it is necessary to disassemble the heating kettle or reboiler tubes or reboiler to clean the residue. Since the positive photoresist has high hardness and strong viscosity after curing, the total time for disassembling and assembling the heating kettle or reboiler and cleaning is about 10 hours, and the cleaning frequency is 2 to 3 days / time. The impact is mainly reflected in energy loss, production efficiency, and operation intensity, which can be optionally reflected in three aspects. First, with continuous feed heating, the polymer adhered to the tubes thickens, the heating efficiency is reduced, and steam energy loss is caused; second, the downtime is long and the production efficiency is reduced; third, the adhered heating tubes need to be cleaned by hammering and high-pressure equipment, and the operation intensity is high.

[0005] At present, the mainstream method in actual production is to remove slag from the tubes after heating. The methods mainly include: hammering, drilling and grinding, high-pressure equipment cleaning, heating tube bundle overall incineration to remove slag, etc. The above methods have good slag removal effects, but also greatly affect production efficiency and increase labor intensity. At the same time, due to the odor of the material itself, there will be greater environmental risks when cleaning the tubes in an open environment. It is not difficult to see that there is an urgent need for a method to solve the problem of waste diluent positive photoresist polymerization and adhesion in the production process, so as to improve energy utilization efficiency, improve production continuity, reduce the labor intensity of front-line employees, and reduce the environmental risks of cleaning the tubes after the process. Utility Model Content

[0006] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a PGMEA waste liquid treatment system, in which a free radical inhibitor is added before heating the PGMEA waste liquid, after being mixed evenly, the PGMEA product is recovered by heating under vacuum conditions, and as the liquid is concentrated to more than 15w / w% of the raw material volume, the following four problems that currently exist are mainly solved: (1) during the heating of the PGMEA waste diluent, the photoresist is concentrated and adhered to the heating tube bundle, and the heat exchange efficiency of the heat source is reduced, resulting in increased energy loss; (2) during the traditional disassembly and cleaning of the tube bundle, there is a strong odor and a high environmental risk; (3) the disassembly and assembly time is long, which affects the continuous production time and reduces the production efficiency; (4) the disassembly and assembly of the heating tube bundle is labor-intensive.

[0007] In order to solve the above problems, the utility model provides a PGMEA waste liquid treatment system.

[0008] Specifically, a waste liquid treatment system is provided, which is characterized by comprising a raw material tank, an auxiliary material temporary storage tank, a stirring tank, a distillation tower, a condenser, and a product temporary storage tank, wherein the raw material tank, the stirring tank, the distillation tower, the condenser, and the product temporary storage tank are connected in sequence by pipelines, and the stirring tank and the auxiliary material temporary storage tank are connected by a pipeline.

[0009] Optionally, the raw material tank is used to hold PGMEA waste liquid, the auxiliary material temporary storage tank is used to hold inhibitor, the stirring tank is used to mix PGMEA waste liquid with inhibitor, the distillation tower is used to fractionate PGMEA waste liquid and obtain PGMEA product through the condenser, and the product temporary storage tank is used to hold PGMEA product.

[0010] Optionally, a heating kettle or a reboiler is further provided between the stirring tank and the distillation tower, the heating kettle or the reboiler is connected to the heavy component return pipe of the distillation tower, and the heating kettle or the reboiler is used to heat the waste liquid and the inhibitor.

[0011] Optionally, a fore fraction temporary storage tank is provided before the auxiliary material temporary storage tank, and the fore fraction temporary storage tank is used for mixing materials with the auxiliary material temporary storage tank.

[0012] Optionally, a heavy component delivery pump is connected after the heating kettle or the reboiler, and the heavy component delivery pump is arranged in parallel with the distillation tower, and the heavy component delivery pump is used to collect the heavy components after distillation in the PGMEA waste liquid.

[0013] Optionally, a fore-fraction temporary storage tank and a cold trap are connected after the condenser, and the cold trap, the fore-fraction temporary storage tank, and the product temporary storage tank are arranged in parallel; the condenser and the cold trap are also connected to the condenser through a liquid return pipe; the fore-fraction temporary storage tank is used to collect components other than the PGMEA product and is used to mix with the auxiliary material temporary storage tank.

[0014] Optionally, a fore-fraction delivery pump is connected after the fore-fraction temporary storage tank, an auxiliary material mixed liquid delivery pump is connected after the auxiliary material temporary storage tank, a feed pump is connected after the stirring tank, and a vacuum pump is connected after the cold trap, and the vacuum pump is used to collect tail gas; the fore-fraction temporary storage tank, the raw material tank, the auxiliary material temporary storage tank, and the stirring tank are provided with liquid level gauges.

[0015] Optionally, the PGMEA waste liquid includes propylene glycol methyl ether acetate, methyl 3-methoxypropionate, cyclohexanone, ethyl 3-ethoxypropionate, 3-methoxybutyl acetate, resin monomer, resin, pigment, carbon black, dispersant and photoinitiator; and the PGMEA waste liquid is at room temperature.

[0016] Optionally, the inhibitor is inhibitor 701, and the amount of the inhibitor added is greater than 0.1w / w% based on the total mass of the waste liquid; the volume of the PGMEA waste liquid raw material after heating and concentration is not less than 15v / v% of the raw material volume.

[0017] Optionally, the vacuum degree of the vacuum pump is lower than -0.096 MPa; the temperature of the heating kettle or reboiler is not higher than 160°C.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] (1) The utility model uses the polymerization inhibitor 701 to mix and dissolve with the PGMEA front fraction or raw material, and then adds it to the waste diluent raw material at a ratio of not less than 0.1w / w% and fully mixes it. Under stable vacuum conditions, the device temperature is not higher than 160°C to recover the PGMEA product. After the recovery is completed, there is no phenomenon of photoresist polymerization in the waste PGMEA diluent sticking to the heating tube bundle and the kettle wall. Compared with the existing mainstream method of removing slag from the tubes after heating, which mainly includes: knocking, drilling and grinding, high-pressure equipment cleaning, heating tube bundle overall incineration and slag removal, etc., the utility model method solves the problem of heating tube bundle adhesion and blockage during the heating process, avoiding the photoresist concentration and adhesion during the heating process of the PGMEA waste diluent. The heat exchange efficiency of the heating tube bundle is reduced, which leads to increased energy loss; the problem of odor generation during the traditional disassembly and cleaning of the tubes is reduced, and the environmental risk is reduced; there is almost no need to disassemble the heating kettle or reboiler and replace the heating tube bundle, which prolongs the continuous production time and greatly improves the production efficiency; and the labor intensity of the workers is well reduced.

[0020] (2) The whole process has a single auxiliary material, good polymerization inhibition effect, and a small amount of addition, which fully ensures that the quality of the recycled waste PGMEA diluent product is not affected, and the cost per ton of addition is low. In addition, no harmful waste is basically generated in the process, which truly solves the problem of heating tube bundle blockage in the process of recycling waste diluent, reduces the time for disassembly and cleaning of the heating tube bundle and the labor intensity of workers, extends the continuous production time, ensures the heating efficiency of the heating kettle or reboiler during the continuous heating process, saves heat source, and is a green, efficient, and low-cost method. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The utility model discloses a schematic diagram of a waste liquid treatment system.

[0022] The reference numerals in the figure are represented as follows: 1-front fraction temporary storage tank 1, 2-raw material tank, 3-distillation tower, 4-condenser, 5-vacuum pump, 6-liquid level gauge 1, 7-liquid level gauge 2, 8-cold trap, 9-raw material delivery pump, 10-mixing tank, 11-auxiliary material temporary storage tank, 12-liquid level gauge 3, 13-liquid level gauge 4, 14-auxiliary material mixed liquid delivery pump, 15-front fraction temporary storage tank 2, 16-product temporary storage tank, 17-feed pump, 18-heavy component delivery pump, 19-heating kettle or reboiler, 20-front fraction delivery pump. DETAILED DESCRIPTION

[0023] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] To achieve the above objectives, the technical solution of the utility model is as follows:

[0025] Example 1

[0026] The system described in this embodiment 1 can be divided into four processing steps: auxiliary material raw material batching, mixing, distillation recovery of PGMEA products and separation of heavy components.

[0027] S100: weigh raw materials and inhibitor;

[0028] S200: assemble the distillation device;

[0029] S300: distillation recovery;

[0030] S400: Component separation.

[0031] Optionally, the specific steps of the embodiment are as follows.

[0032] S101: Weigh 320 g of waste diluent raw material (black, containing positive photoresist), raw material composition: 0.18 w / w% propylene glycol methyl ether, 73.1 w / w% propylene glycol methyl ether acetate, 8.9 w / w% photoresist, 2.66 w / w% cyclohexanone, 4.18 w / w% 3-methoxypropionic acid methyl ester, 6.28 w / w% 3-ethoxypropionic acid ethyl ester, 2.05 w / w% 3-methoxybutyl acetate, 1.09 w / w% diethylene glycol diethyl ether, 0. .87w / w%, moisture 0.69w / w%, weigh inhibitor 701 according to 0.1% of the total weight of raw materials, weigh 0.32g of inhibitor 701 in a beaker, add 2ml of PGMEA front fraction (which can be replaced by raw materials or water), stir with a glass rod to dissolve until there is no solid, then pour into the waste diluent raw material, shake and stir to mix evenly, record as Example 1, take another three-necked flask to weigh 320g of the same waste diluent raw material (black, containing positive photoresist), record as Comparative Example 1, there is no obvious difference in appearance between the two groups.

[0033] S201: Assemble two sets of distillation devices, including: three-necked flask, heating jacket, distillation column, glass spring packing, condenser, iron stand, circulating water vacuum pump, conical flask, thermometer, vacuum receiving tube, distillation head, upper and lower water rubber pipes, frosted glass stopper, etc. Apply vaseline to each connection port to ensure the sealing of the device.

[0034] S301: After the distillation device is built, the circulating water vacuum pump is turned on, the pressure is stabilized at -0.096Mpa, and the heating jacket is turned on to start heating. Example 1 and Comparative Example 1 both start bubbling at 72°C in the three-necked flask, and then liquid beads appear on the condenser tube. After that, the distillate is stably extracted to a temperature of 75°C and stops. At this time, the extracted distillate components are mainly composed of water and a small part of propylene glycol methyl ether acetate, which is called the front distillate. The temperature is raised to 92°C, and a distillate appears. At this time, the extracted distillate components are mainly composed of propylene glycol methyl ether acetate, which is called the middle distillate. The extraction stops at 95°C. The appearance of the material in the three-necked flask of Comparative Example 1 is black, and the boiling bubbles splash onto the wall of the three-necked flask. It can be seen that the liquid bubble has poor fluidity and leaves marks on the wall of the flask. When the marks flow back to the flask material, there are tiny slag particles on the wall. As the flask material boils and washes, the tiny slag particles return to the material. When no distillate is evaporated at 95°C, the volume of the material in the flask is visually estimated to be about 40w / w% of the raw material amount. Example 1 has a black appearance, good material fluidity, no flask wall adhesion, and no slag particles. At this time, the volume of the material in the flask is visually about 40w / w% of the raw material. Continue to heat up, and when the temperature reaches 103°C, a fraction is extracted. When the temperature rises to 108°C, the fraction components extracted at this time are mainly composed of part of propylene glycol methyl ether acetate and heavy components with a higher boiling point than propylene glycol methyl ether. The main components left in the flask are photoresist and the remaining high-boiling substances. At 108°C, the volume of the material in the flask is visually about 20w / w% of the raw material. Comparative Example 1 has a coking thin layer on the wall of the three-necked flask, and the coking layer has no fluidity. A thumb-sized agglomerate appears in the center of the remaining material. The remaining material has poor liquid fluidity, and the material is bright black and opaque. Example 1 The material is black, with a liquid layer on the wall, the liquid layer is dark purple-pink, there is no coking phenomenon in the center of the remaining material and the flask wall, and the material has strong fluidity. Continue heating. When the temperature is 138°C, there is basically no fraction produced. Since the heating kettle or reboiler will not be evaporated to dryness in actual production, the fraction collected in the conical flask is about 280ml, and the remaining material is visually about 15w / w% of the raw material amount. Stop heating, cool to 50-60°C, disassemble the three-necked flask, shake for comparison, the material of comparative example 1 is in a solid-liquid state, and a thin layer of coke is adhered to the wall of the flask, which is difficult to remove using a glass rod, a brush, or a weighing iron spoon. The material of embodiment 1 still has high fluidity after shaking. After shaking, the liquid does not adhere to the wall of the flask. The glass remains clean before feeding, and all the remaining materials can be easily poured out.

[0035] S401: The material in the conical flask for collecting the fractions is a colorless transparent liquid. Pour all the fractions in the conical flask into the sample delivery bottle for full analysis and detection. The composition of the test fractions is: 1.32w / w% propylene glycol methyl ether, 88.03w / w% propylene glycol methyl ether acetate, 5.94w / w% cyclohexanone, 0.76w / w% 3-ethoxypropionic acid ethyl ester, 1.85w / w% 3-methoxybutyl acetate, 1.15w / w% diethylene glycol diethyl ether, and 0.95w / w% water. Since the purpose of this experiment is mainly to verify the coking of PGMEA materials in the utility model by adding inhibitor 701 and recovering PGMEA waste liquid normally without adding inhibitor, the extracted fractions are not packaged and measured.

[0036] Among them, the main component of inhibitor 701 is the nitrogen oxide free radical piperidinol, the chemical name is 4-hydroxy-2,2,6,6-tetramethylpiperidinol (free radical), which is an orange crystalline solid. Its mixture is a mixture obtained by evenly dissolving the fore fraction or raw material in the waste diluent raw material recovery process, including but not limited to other types of inhibitors or substances containing free radicals and their mixtures. The mixture can also use other media that can dissolve the inhibitor to dissolve the inhibitor, which are all deemed to be within the scope of protection of the present utility model.

[0037] Comparative Example 1

[0038] The difference between Comparative Example 1 and Example 1 is that no polymerization inhibitor is added to the raw materials.

[0039] Example 2

[0040] See Figure 1 The auxiliary material preparation process is composed of 1-pre-fraction temporary storage tank 1, 6-liquid level gauge 1, 20-pre-fraction delivery pump, 2-raw material tank, 7-liquid level gauge 2, 9-raw material delivery pump, 11-auxiliary material temporary storage tank, 12-liquid level gauge 3, and 14-auxiliary material mixed liquid delivery pump. The top of the 11-auxiliary material temporary storage tank is provided with a feeding port, and a certain weight of the inhibitor 701 can be weighed and then fed into the 11-auxiliary material temporary storage tank through the feeding port. The 1-pre-fraction temporary storage tank is used to store the PGMEA pre-fraction, and the 2-raw material tank is used to store the waste PGMEA waste liquid raw material, which is respectively transported by the pump 20-pre-fraction delivery pump and the 9-raw material delivery pump, and the input amount is controlled by observing the 6-liquid level gauge 1 and the 7-liquid level gauge 2 to enter the 11-auxiliary material temporary storage tank. The pre-fraction and the raw material are both used to dissolve the inhibitor 701. The use of the two materials ensures that the dissolution inhibitor can be continuously supplied in actual production. It is recommended that the ratio of the pre-fraction or raw material to the inhibitor is 3:2 to avoid the poor inhibition effect of the inhibitor 701 when it is mixed with the raw material later due to excessive pre-fraction and raw material, see Figure 111-auxiliary material temporary storage tank and 14-auxiliary material mixed liquid delivery pump are connected by pipelines to realize the circulation, mixing and dissolution of the inhibitor 701 and the front fraction or raw material inside the tank, so as to facilitate the mixing and batching with the raw material in the next step.

[0041] See Figure 1 The mixing process equipment includes 2-raw material tank, 7-liquid level gauge 2, 9-raw material delivery pump, 10-mixing tank, 11-auxiliary material temporary storage tank, 12-liquid level gauge 3, 13-liquid level gauge 4, and 14-auxiliary material mixed liquid delivery pump. After the auxiliary material preparation is completed, the liquid auxiliary material will be pumped into the 10-mixing tank through the 14-auxiliary material mixed liquid delivery pump, and the liquid level change and liquid level difference will be recorded through the 13-liquid level gauge 4. The raw material feed amount of the 10-mixing tank is calculated based on the 0.1w / w% inhibitor addition amount. The raw material in the 2-raw material tank is transported to the 10-mixing tank through the 9-raw material delivery pump according to the final liquid level gauge reading calculated above. Turn on the 10-mixing tank motor for stirring evenly and then set aside.

[0042] See Figure 1 The distillation recovery process of PGMEA product consists of 3-distillation tower, 4-condenser, 5-vacuum pump, 8-cold trap, 15-temporary storage tank for front fraction, 16-temporary storage tank for product, 17-feed pump, 19-heating kettle or reboiler. The raw material and polymerization inhibitor 701 mixed liquid are transported from 10-stirring tank to 19-heating kettle or reboiler through 17-feed pump. 5-vacuum pump is a water ring vacuum pump with a stable vacuum degree above -0.096MPa. One end of 5-vacuum pump is connected to the device and the other end is connected to the tail gas treatment system. The tail gas treatment system consists of 1 cold The gas phase material is condensed by 4-condenser of tube-side circulating water medium and 8-cold trap of tube-side refrigerated liquid medium, and a part of it returns to 3-distillation tower, and a part of it is taken out to 15-pre-fraction temporary storage tank and 16-product temporary storage tank. The pre-fraction is taken out to 15-pre-fraction temporary storage tank, and the product is taken out to 16-product temporary storage tank, and the heavy component is retained in 19-heating kettle or reboiler.

[0043] See Figure 1 The heavy component separation process equipment includes 18-heavy component delivery pump, 19-heating kettle or reboiler. After distillation recovery, the heavy component is added with inhibitor 701, which has strong fluidity and does not stick to the kettle wall. It can be directly transported to the ton barrel for further processing through 18-heavy component delivery pump.

[0044] The main technical key point of the utility model is to add the dissolved inhibitor 701 to the untreated PGMEA waste liquid raw material and stir it evenly, and use vacuum distillation to recover the product. The specific parameters are that the weight of the inhibitor (solid) is not less than 0.1w / w% of the weight of the added PGMEA waste liquid raw material, and the temperature of the vacuum distillation kettle is lower than 160°C. This experiment uses a water ring vacuum pump with a pressure of -0.096MPa, and the volume of the remaining material in the heating kettle or reboiler is not less than 15w / w% of the raw material volume. The whole process has a single auxiliary material, good inhibitory effect, and a small amount of addition, which fully guarantees that the quality of the recycled waste PGMEA diluent product is not affected, and the cost of adding per ton is low. In addition, basically no harmful waste is generated in the process, which truly solves the problem of heating tube bundle blockage in the process of waste diluent recycling, reduces the time for disassembly and cleaning of the heating tube bundle and the labor intensity of workers, and extends the continuous production time. It is a green, efficient and low-cost method.

[0045] The above embodiments are used to explain the present invention rather than to limit the present invention. Any modification and change made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A waste liquid treatment system, characterized in that: It includes a raw material tank, an auxiliary material temporary storage tank, a stirring tank, a distillation tower, a condenser, and a product temporary storage tank. The raw material tank, the stirring tank, the distillation tower, the condenser, and the product temporary storage tank are connected in sequence by pipelines, and the stirring tank and the auxiliary material temporary storage tank are connected by pipelines.

2. The waste liquid treatment system according to claim 1, characterized in that: The raw material tank is used to hold PGMEA waste liquid, the auxiliary material temporary storage tank is used to hold inhibitor, the stirring tank is used to mix PGMEA waste liquid with inhibitor, the distillation tower is used to fractionate PGMEA waste liquid and obtain PGMEA product through the condenser, and the product temporary storage tank is used to hold PGMEA product.

3. The waste liquid treatment system according to claim 1, characterized in that: A heating kettle or a reboiler is also provided between the stirring tank and the distillation tower. The heating kettle or the reboiler is connected to the heavy component return pipe of the distillation tower and is used to heat the waste liquid and the inhibitor.

4. The waste liquid treatment system according to claim 1, characterized in that: A front fraction temporary storage tank is arranged before the auxiliary material temporary storage tank, and the front fraction temporary storage tank is used for mixing materials with the auxiliary material temporary storage tank.

5. The waste liquid treatment system according to claim 3, characterized in that: A heavy component delivery pump is connected after the heating kettle or the reboiler. The heavy component delivery pump is arranged in parallel with the distillation tower. The heavy component delivery pump is used to collect the heavy components after distillation in the PGMEA waste liquid.

6. The waste liquid treatment system according to claim 1, characterized in that: A front fraction temporary storage tank and a cold trap are connected after the condenser, and the cold trap, the front fraction temporary storage tank and the product temporary storage tank are arranged in parallel; and / or A vacuum pump is connected after the cold trap, and the vacuum pump is used to collect tail gas; and / or The condenser and the cold trap are also connected to the condenser via a liquid return pipe; and / or The front fraction temporary storage tank is used to collect components other than the PGMEA product and is used to mix with the auxiliary material temporary storage tank.

7. The waste liquid treatment system according to claim 6, characterized in that: The front fraction temporary storage tank is connected to a front fraction delivery pump, the auxiliary material temporary storage tank is connected to an auxiliary material mixed liquid delivery pump, and the stirring tank is connected to a feed pump; and / or The front fraction temporary storage tank, the raw material tank, the auxiliary material temporary storage tank, and the stirring tank are provided with liquid level gauges.

8. The waste liquid treatment system according to claim 2, characterized in that: The PGMEA waste liquid includes propylene glycol methyl ether acetate, methyl 3-methoxypropionate, cyclohexanone, ethyl 3-ethoxypropionate, 3-methoxybutyl acetate, resin monomer, resin, pigment, carbon black, dispersant, photoinitiator; and / or The PGMEA waste liquid is at room temperature.

9. The waste liquid treatment system according to claim 2, characterized in that: The polymerization inhibitor is polymerization inhibitor 701, and the amount of polymerization inhibitor added is greater than 0.1 w / w% based on the total mass of the waste liquid; and / or The volume of the PGMEA waste liquid raw material after heating and concentration is not less than 15 v / v% of the raw material volume.

10. The waste liquid treatment system according to claim 3, characterized in that: The temperature of the heating kettle or the reboiler is not higher than 160°C.

11. The waste liquid treatment system according to claim 6, characterized in that: The vacuum degree of the vacuum pump is lower than -0.096MPa.

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