TWI643657B - System and method for processing waste solvent - Google Patents

Abstract

The waste solvent treatment system includes a divided wall distillation column, a first inlet, an evaporation heating device, a first pump, a second pump, a first reboiler, a third pump, and a first condenser. The dividing wall divides the dividing wall distillation column into a first space, a second space, and a third space. The first inlet is connected to the first space to receive a mixture containing a high-boiling substance, a middle-boiling substance, and a low-boiling substance. The first pump is connected to an evaporative heating device to extract high-boiling substances. The second pump is connected to the first space to extract the high-boiling substance and the middle-boiling substance into the evaporation heating device. The third pump is connected to the second space to extract the medium boiling point substance. The first condenser is connected to the third space to condense low-boiling substances discharged from the third space.

Description

Waste solvent processing system and method

The invention relates to a waste solvent processing system and a method thereof, and in particular to a waste solvent processing system and a method thereof capable of separating a plurality of boiling point substances.

As human demand for electronic products is increasing, the waste of resources and environmental issues arising from the manufacturing process of electronic products are becoming more serious. At present, although there are some methods for treating waste solutions of electronic products, they have not been able to efficiently treat waste solutions.

Therefore, the research on waste solvent treatment technology is still an urgent issue.

Embodiments of the present invention provide a waste solvent processing system and a method thereof. Since the waste solvent treatment system and method of the present invention use a divided wall distillation column, it is possible to separate high and medium boiling points and low boiling points from a single divided wall distillation column without using multiple distillation columns. And further recover the medium boiling point materials for reuse. Therefore, the waste solvent processing system and method of the present invention can achieve the purpose of saving hardware investment and operating costs.

According to an embodiment of the present invention, a waste solvent processing system is proposed. The waste solvent treatment system includes a divided wall distillation column, a first inlet, an evaporation heating device, a first pump, a second pump, a first reboiler, a third pump, and a first pump. A condenser, a storage tank, and a fourth pump. The divided-wall distillation column includes a packed bed and a partition plate. The partition plate divides the interior of the divided-wall distillation column into a first space, a second space, and a third space. The first inlet is directly or indirectly connected to the first space and is used to receive a mixture. The mixture contains a high boiling point substance, a medium boiling point substance and a low boiling point substance. The evaporative heating device is used to receive the mixture and concentrate the high-boiling substances. The first pump is connected to a first bottom of the evaporative heating device, so as to extract high boiling point substances in the evaporative heating device. The second pump is connected to a second bottom of the first space to extract high-boiling substances and middle-boiling substances in the first space into the evaporation heating device. The first reboiler provides heat to the second space. The third pump is connected to a third bottom of the second space and is used to extract the boiling point substances in the second space. The first condenser is connected to the third space and is used to condense low-boiling substances discharged from the third space. The storage tank is connected to the first condenser to store low-boiling substances discharged from the first condenser. The fourth pump is connected to the storage tank to extract a part of the low-boiling substances in the storage tank, and draw the other part of the low-boiling substances into the third space.

According to another embodiment of the present invention, a method for treating a waste solvent according to an embodiment of the present invention is provided. The method includes the following steps. First, the mixture is provided in the waste solvent treatment system as described above, so that the mixture enters the first space through the first inlet. Secondly, heat is provided to the first space, so that the mixture is distributed from the first space to the second space and the third space. The mixture was received by an evaporative heating device, and a high-boiling point substance was concentrated. By the first gang connected to the first bottom of the evaporative heating device Pump out high boiling point substances from the evaporative heating device. The second pump connected to the second bottom of the first space is used to extract the high-boiling and middle-boiling substances in the first space into the evaporation heating device. With the first reboiler, heat is provided to the second space. With the third pump connected to the third bottom of the second space, the boiling point substance in the second space is extracted. The first condenser connected to the third space condenses the low-boiling substances discharged from the third space. The storage tank connected to the first condenser stores low-boiling substances discharged from the first condenser. With a fourth pump connected to the storage tank, one part of the low boiling point substance in the storage tank is pumped out, and the other part of the low boiling point substance is pumped back into the third space.

In order to have a better understanding of the above and other aspects of the present invention, preferred embodiments are described below in conjunction with the accompanying drawings, and are described in detail below, but not limited thereto.

10, 20, 30, 40‧‧‧ waste solvent treatment system

100‧‧‧ divided wall distillation column

100A‧‧‧First Space

100B‧‧‧Second Space

100C‧‧‧Third Space

101‧‧‧ packed bed

103, 1031, 1032, 1033‧‧‧ First entrance

107‧‧‧Top

105‧‧‧ divider

110‧‧‧ evaporation heating device

121‧‧‧The first reboiler

122‧‧‧Second reboiler

131‧‧‧first condenser

132‧‧‧Second condenser

133‧‧‧Third condenser

134‧‧‧Fourth condenser

135‧‧‧Fifth condenser

141‧‧‧Storage tank

151‧‧‧First Pump

152‧‧‧Second Pump

153‧‧‧Third Pump

154‧‧‧Fourth Pump

155‧‧‧Fifth Pump

156‧‧‧Sixth Pump

157‧‧‧Seventh Pump

161‧‧‧preheater

b1‧‧‧first bottom

b2‧‧‧ the second bottom

b3‧‧‧ third bottom

G‧‧‧ exhaust gas

M‧‧‧ Mixture

MH‧‧‧High boiling point substance

MM‧‧‧Middle boiling point substance

ML‧‧‧Low boiling point substance

FIG. 1 is a schematic diagram of a waste solvent processing system according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a waste solvent processing system according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a waste solvent processing system according to an embodiment of the present invention.

FIG. 4 is a schematic diagram of a waste solvent processing system according to an embodiment of the present invention.

The following describes several embodiments of the present invention with reference to the attached drawings to describe related systems and methods. However, the present invention is not limited to this aspect, and not all possible embodiments are shown. The same or similar reference numerals in the embodiments are used to indicate the same or similar parts. Furthermore, other implementations not proposed in the present invention may also be applicable. Those skilled in the relevant art may change and modify the structure of the embodiments without departing from the spirit and scope of the present invention, so as to meet the requirements of practical applications. The drawings have been simplified to clearly explain the contents of the embodiments, and the dimensional proportions on the drawings are not drawn according to the actual products. Therefore, the contents of the description and the drawings are only used to describe the embodiments, rather than to limit the scope of protection of the present invention.

Furthermore, ordinal numbers such as "first" and "second" used in the description and the request are used to modify the elements of the request, and they do not themselves imply and represent that the request has any previous The ordinal number does not represent the order of one request element and another request element, or the order of manufacturing methods. The use of these ordinal numbers is only used to enable a request element with a certain name to be a request with the same name as another request. The components make a clear distinction.

FIG. 1 is a schematic diagram of a waste solvent processing system 10 according to an embodiment of the present invention.

The waste solvent processing system 10 includes a divided-wall distillation column 100, an evaporation heating device 110, a first pump 151, a second pump 152, a first reboiler 121, a third pump 153, a first condenser 131, and a storage. The tank 141, the fourth pump 154, the second condenser 132, and the fifth pump 155. These two components can be connected by a solid pipeline to transfer the fluid between them.

The divided-wall distillation column 100 includes a packed bed 101, a first inlet 103, and a partition plate 105. The partition plate 105 divides the interior of the divided-wall distillation column 100 into The first space 100A, the second space 100B, and the third space 100C. The first space 100A and the second space 100B are located in the lower part of the divided wall distillation column 110, and the third space 100C is located in the upper part of the divided wall distillation column 100. The partition plate 105 may include a vertical partition plate that partitions the first space 100A and the second space 100B in a horizontal direction. The dividing plate 105 may be located in the lower half of the dividing wall distillation column 100. The height of the dividing plate 105 is 10% to 90% of the total height of the dividing wall distillation column 100. The dividing plate 105 is in the dividing wall distillation column. The cross-sectional area of the first space 100A or the second space 100B divided in 100 is 20% to 80% of the total cross-sectional area of the divided-wall distillation column 100.

The first inlet 103 may be directly or indirectly connected to the first space 100A. The first inlet 103 may be a single inlet or multiple inlets, and may be disposed at any position on an outer side of the first space 100A of the divided wall distillation column 100, the inlet of the evaporation heating device 110, or a combination thereof. position. In this embodiment, the first inlet 103 includes a first inlet 1031 provided on an outer side of the first space and a first inlet 1032 provided at an inlet of the evaporation heating device.

The first inlet 103 can be used to receive a mixture M. The mixture M may include a high boiling point substance MH, a medium boiling point substance MM, and a low boiling point substance ML. The high-boiling point substance MH, the middle-boiling point substance MM, and the low-boiling point substance ML may include a plurality of substances having different boiling points, respectively. Mixture M can come from used photoresist strippers, photoresist thinners or wafer cleaning agents discharged from liquid crystal display panels or semiconductor manufacturing plants, or organic or inorganic mixed waste liquids discharged from various chemical material production processes.

The medium boiling point substance MM may be the target of recovery, and may be a single substance or a mixed substance, for example, selected from the group consisting of Propylene glycol methyl ether (PGME), Propylene Glycol methyl ether Acetate, PGMEA), ethyl 3-ethoxypropionate (Ethyl 3-ethoxypropionate (EEP), Ethanolamine (MEA), Dimethyl sulfoxide (DMSO), Diethylene glycol monobutyl ether (BDG), N methylpyrrolidone (N -Methyl-2-Pyrrolidone (NMP), Cyclohexone, Cyclopentanone, Ethyl Lactate, N, N-Dimethylacetamide (DMAc), Triethanolamine (Triethanolamine, TEA), Diethylene glycol methyl ether, N-Methylformamide and any combination thereof. Under normal pressure, the boiling point of the medium boiling point substance MM may be greater than 100 ° C and less than 250 ° C.

The high boiling point substance MH may be a single substance or a mixed substance having a boiling point higher than the middle boiling point substance MM. For example, the high-boiling substance MH may include a polymer resin substance that can be dissolved by the medium-boiling substance MM, and a solid substance that cannot be dissolved by a solvent. Under normal pressure, the boiling point of the high boiling point substance MH may be equal to or greater than 250 ° C.

The low boiling point substance ML may be a single substance or a mixed substance having a lower boiling point than the medium boiling point substance MM, such as water. Under normal pressure, the boiling point of the low boiling point substance ML may be equal to or lower than 100 ° C.

Through the waste solvent processing system 100 according to the embodiment of the present invention, components with different boiling points in the mixture M can be separated, and the solid content of the mixture M is between 0 wt% and 60 wt%. In the following, it will be explained how to separate the components with different boiling points of the mixture M. In this embodiment, the mixture M is, for example, a substance containing several different boiling points, such as a high boiling point substance MH, a middle boiling point substance MM, and a low boiling point substance ML.

On the one hand, the evaporative heating device 110 can receive the mixture M and concentrate the high-boiling point material MH. In one embodiment, the evaporative heating device 110 can simultaneously raise Heat is supplied to the first space 100A, so that the mixture M is distributed from the first space 100A to the second space 100B and the third space 100C. For example, the evaporative heating device 110 provides heat to the first space 100A from below the packed bed 101 of the divided-wall distillation column 100. The first pump 151 is connected to the first bottom b1 of the evaporative heating device 110 to extract the high-boiling point material MH located in the evaporative heating device 110. When the extracted high-boiling point material MH drops to room temperature, it almost assumes a semi-solid state. Too flowing. The evaporation heating device 110 may be an evaporator or a dryer, so that the high-boiling point material MH after heating can further remove the middle-boiling point material MM and the low-boiling point material ML.

In addition, the heating temperature of the evaporative heating device 110 may be higher than the boiling point of the medium-boiling point substance MM, so that the medium-boiling point substance MM and the low-boiling point substance ML can be evaporated into a vapor state, and are distributed upward in the first space 100A, the second space 100B, and The third space is 100C. Above the first space 100A and the second space 100B is communicated with the third space 100C, but the first space 100A and the second space 100B are separated by the upright partition plate 105, and the middle boiling point in the first space 100A The substance MM and the low-boiling substance ML can only move through the top of the first space 100A to the second space 100B or the third space 100C.

The second pump 152 is connected to the second bottom b2 of the first space 100A, and the high-boiling point material MH and part of the middle-boiling point material MM can be extracted from the second bottom b2 of the first space 100A, and then provided to the evaporation heating device 110, so that The evaporative heating device 110 can further vaporize the medium-boiling substance MM existing therein to the first space 100A, and the remaining high-boiling substance MH is extracted from the first pump 151, and the solid content of the extracted high-boiling substance MH is between 20wt. % To 70wt%.

The first reboiler 121 provides heat to the second space. The third pump 153 is connected to the third bottom b3 of the second space 100B to draw out the second space 100B. Medium-boiling point material MM and some low-boiling point material ML. The first reboiler 121 further vaporizes the low-boiling-point substance ML extracted by the third pump 153 to the divided wall distillation column 100 and moves to the third space 100C. In an embodiment, the high-boiling substance MH may also exist in the second space 100B, and the third pump 153 may also extract the high-boiling substance MH in the second space 100B.

The low-boiling substance ML in a vapor state can be discharged from the top 107 of the divided-wall distillation column 100 to the outside. The first condenser 131 can condense the low-boiling substance ML in a vapor state discharged from the third space 100C. The storage tank 141 stores a low-boiling-point substance ML discharged from the first condenser 131. The fourth pump 154 is connected to the storage tank 141 to withdraw a part of the low-boiling substance ML in the storage tank 141 from the system, and draw the other part of the low-boiling substance ML in the storage tank 141 to the third space 100C. . Since the low-boiling substance ML drawn back to the third space 100C is liquid, it will flow downward, and can flow into the first space 100A and the second space 100B, so that the medium-boiling substance MM does not move upward to the third space 100C. . The second condenser 132 is connected to the storage tank 141 and is used to cool the low-boiling-point substance ML discharged from the storage tank 141. The fifth pump 155 is connected to the second condenser 132 to perform air extraction (for example, to exhaust the exhaust gas G) and maintain the operating pressure of the waste solvent treatment system. The fifth pump 155 may be a vacuum pump, and the operating pressure is, for example, less than 1 atmosphere. The second condenser 132 can be used to reduce the temperature of the fifth pump 155 during pumping to ensure that the vapor pressure of the passing fluid is lower than or equal to the operating pressure.

FIG. 2 shows a schematic diagram of a waste solvent treatment system 20 according to an embodiment of the present invention. The difference from the waste solvent treatment system of FIG. 1 is that a second reboiler 122 and a fifth condensation can be selectively added. Heater 135, seventh pump 157, preheater 161, or any combination thereof. That is, in one embodiment, the waste solvent treatment system The system 20 adds a second reboiler 122 to the waste solvent processing system 10 without a fifth condenser 135. In one embodiment, the waste solvent processing system 20 adds a fifth condenser 135 to the waste solvent processing system 10 without the second reboiler 122.

Referring to FIG. 2, the second reboiler 122 provides heat to the first space 100A, and vaporizes the mixture M and the middle boiling point substance MM extracted from the second pump 152 to provide the first space 100A. Since the second reboiler 122 can also provide heat to the first space 100A, compared with the comparative example in which only the evaporation heating device 110 is used to provide thermal energy to the first space 100A, the burden of the evaporation heating device 110 can be reduced and the evaporation can be performed. The service life of the heating device 110 can be extended, and it is easier to save the cost of hardware equipment. In this embodiment, the first space 100A can be provided by the evaporation heating device 110 and the second reboiler 122 at the same time, so that the mixture M is distributed from the first space 100A to the second space 100B and the third space 100C. In other embodiments, only the evaporative heating device 110 or the second reboiler 122 can be used to provide heat to the first space 100A. For example, the evaporative heating device 110 can only perform high-boiling point MH concentration (that is, vaporization removal or separation) The medium boiling point material MM and the low boiling point material ML) do not provide heat to the first space 100A.

In an embodiment, the first inlet 103 may be provided at any position on an outer side of the first space 100A of the divided-wall distillation column 100, the inlet of the second reboiler 122, and the inlet of the evaporation heating device 110. , Or any combination of the above. In this embodiment, the first inlet 103 includes a first inlet 1031 provided on the outer side of the first space, a first inlet 1032 provided at the inlet of the evaporation heating device 110, and a second reboiler 122 provided The first entrance 1033 at the entrance.

The preheater 161 is connected to the third pump 153, and is used for connecting the third pump The medium-boiling point substance MM extracted at 153 is subjected to a heat exchange with a supply (for example, a mixture M of waste solvents) to be provided to the waste solvent processing system. The supply (mixture M) is heat-exchanged and then supplied to the waste solvent processing system 20 through a first inlet (for example, 1031, 1032, and 1033). The medium boiling point substance MM extracted by the third pump 153 can be recovered after heat exchange for reuse, wherein the purity of the medium boiling point substance MM is 90 wt% to 100 wt%. The fifth condenser 135 may be connected to the evaporative heating device 110 for condensing the evaporative heating device 110 to vaporize a medium-boiling point substance MM containing no solids, wherein the purity of the medium-boiling point substance MM is 50 wt% to 99 wt%. Since the preheater 161 of the embodiment of the present invention can directly use the thermal energy of the medium-boiling point substance MM extracted by the third pump 153, this stream and the supply (mixture M) to be entered into the waste solvent treatment system The heat exchange is performed, so the embodiments of the present invention can have lower energy consumption than the comparative example without a preheater.

FIG. 3 shows a schematic diagram of a waste solvent processing system 30 according to an embodiment of the present invention. The difference from the waste solvent processing system of FIG. 1 is that it further includes a third condenser 133, a fourth condenser 134, and a first condenser. Six pumps 156.

Referring to FIG. 3, the third condenser 133 is connected to the second space 100B, and is used to cool the boiling point substance MM in the vapor phase in the second space 100B, that is, the middle of the vapor phase extracted from the second space 100B. The boiling point substance MM is subjected to a heat exchange with a supply (for example, a mixture M) to be entered into the waste solvent processing system. The fourth condenser 134 is connected to the third condenser 133 and is used to condense the boiling point substance MM after the third condenser 133 is cooled (after heat exchange). The sixth pump 156 is connected to the fourth condenser 134 to extract the middle boiling point substance MM condensed by the fourth condenser 134. The medium boiling point material MM extracted from the third pump 153 here Together with the heat-exchanged supply (for example, mixture M), it is supplied to the waste solvent processing system 30 through the first inlet (for example, 1031 and 1032). Further, when the mixture M contains metal ions, the metal ions usually exist in the liquid, but not in the vapor, so the boiling point substance MM in the condensed vapor can be recycled and reused for higher requirements on the metal ion specifications Industry. In this embodiment, the purity of the boiling point substance MM in the condensed vapor state is between 90 wt% and 100 wt%. In addition, since the third condenser 133 can first perform a heat exchange between the medium boiling point substance MM of the vapor phase extracted from the second space 100B and the supply (for example, the mixture M) that is to be entered into the waste solvent processing system, this embodiment Compared with the comparative example which does not have a 3rd condenser, energy consumption can be saved more. In other embodiments, the fourth condenser 134 may also be directly connected to the second space 100B, and used to condense the boiling point substance MM in the vapor phase in the second space 100B, and then the sixth connection to the fourth condenser 134 is used. The pump 156 extracts the medium-boiling point substance MM condensed by the fourth condenser 134.

FIG. 4 shows a schematic diagram of a waste solvent processing system 40 according to an embodiment of the present invention. The difference from the waste solvent processing system of FIG. 3 is that a second reboiler 122 and a fifth condensation can be selectively added.器 135. That is, in one embodiment, the waste solvent processing system 40 adds a second reboiler 122 to the waste solvent processing system 30 without the fifth condenser 135. In one embodiment, the waste solvent processing system 40 adds a fifth condenser 135 to the waste solvent processing system 30 without the second reboiler 122. The second reboiler 122 and the fifth condenser 135 of FIG. 4 are the same or similar to the second reboiler 122 and the fifth condenser 135 of FIG. 2.

Referring to FIG. 4, the medium-boiling point material MM that does not contain solids is vaporized from the evaporation device 110. After condensing in the fifth condenser 135, it is extracted by the seventh pump 157 and recovered for reuse. The purity of the substance MM is 50 wt% to 99wt%.

The following table 1 will respectively use Experimental Example 1 of the waste solvent processing system 10 of the embodiment of FIG. 1 of the present invention 1, Experimental Example 2 of the waste solvent processing system 30 of the embodiment of FIG. 3 of the present invention, and two The distillation column further included Comparative Example 1 including an evaporative heating device, two reboilers, and two condensers, and evaluated the performance of waste solvent treatment. The feed conditions of Experimental Example 1, Experimental Example 2 and Comparative Example 1 were 1000 kg / h. The mixture included 5 wt% water, 90 wt% MEA and DMSO, and 5 wt% photoresist resin. In the final product obtained after the treatment with the waste solvent, the water containing the solvent (MEA and DMSO) is less than 500 ppm, the water containing target (MEA and DMSO) is less than 100 ppm, and the remaining bottom residue photoresist resin is 30 wt%.

Experimental Example 1 and Experimental Example 2 of the present invention use a single divided-wall distillation column to separate low-boiling substances, medium-boiling substances, and high-boiling substances in the mixture, while Comparative Example 1 requires the use of two distillation columns for separation. Therefore, compared with Comparative Example 1, the experimental examples 1 and 2 obtained by using the system and method of the present invention can save costs on the hardware equipment and reduce the space used.

Furthermore, from the comparison results of the performance in Table 1, it can be known that, compared with Comparative Example 1, Experimental Examples 1 and 2 of the present invention have lower energy consumption and energy saving effects.

Embodiments of the present invention provide a waste solvent processing system and a method thereof. Because the waste solvent treatment system and method of the present invention do not use a double column for distillation, the high-boiling point, middle-boiling point, and low-boiling point materials are separated by the single divided-wall distillation column, and the divided-wall distillation is used. The material separated from the column is heat exchanged with the material to be supplied to the divided-wall distillation column to reduce energy consumption, and the medium boiling point material is further recovered for reuse. Therefore, the waste solvent processing system and method of the present invention can achieve the purpose of saving hardware investment and operating costs.

In summary, although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope of the attached patent application.

Claims (20)

A waste solvent treatment system includes a divided wall distillation column including a packed bed, a first inlet, and a partition plate. The partition plate divides the interior of the divided wall distillation column into a first space, a A second space and a third space, the first inlet is directly or indirectly connected to the first space and is used for receiving a mixture containing a high boiling point substance, a middle boiling point substance and a low boiling point substance; an evaporation A heating device for receiving the mixture and concentrating the high-boiling substance; a first pump connected to a first bottom of the evaporative heating device to extract the high-boiling substance in the evaporative heating device; a second Pump connected to a second bottom of the first space to extract the high-boiling substance and the middle-boiling substance in the first space into the evaporation heating device; a first reboiler that provides heat to The second space; a third pump connected to a third bottom of the second space for extracting the medium boiling point substance in the second space; a first condenser connected to the third space , And used to Condensing the low boiling point substance discharged from the third space; a storage tank connected to the first condenser to store the low boiling point substance discharged from the first condenser; and a fourth pump connected to The storage tank is configured to extract a part of the low boiling point substance in the storage tank, and to draw the other part of the low boiling point substance into the third space. The waste solvent treatment system according to item 1 of the scope of the patent application, further comprising: a preheater connected to the third pump for the middle boiling point substance and the mixture extracted by the third pump A heat exchange is performed, wherein the mixture enters the waste solvent treatment system through the first inlet after the heat exchange. The waste solvent treatment system according to item 1 of the scope of patent application, further comprising: a third condenser connected to the second space, and used to cool the middle boiling point substance in the vapor phase in the second space, and The medium-boiling point substance in the vapor phase undergoes a heat exchange with the mixture, and after the mixture performs the heat exchange, it enters the waste solvent treatment system through the first inlet; a fourth condenser is connected to the third condenser, And for condensing the medium boiling point substance cooled by the third condenser; and a sixth pump connected to the fourth condenser to extract the medium boiling point substance condensed by the fourth condenser. The waste solvent processing system according to item 1 of the scope of patent application, further comprising: a fourth condenser connected to the second space and used to condense the medium boiling point substance in the vapor phase in the second space; and A sixth pump is connected to the fourth condenser to extract the medium boiling point substance condensed by the fourth condenser. The waste solvent treatment system according to item 1 or 3 of the scope of patent application, further comprising: a second reboiler, which provides heat to the first space, and performs the middle-boiling substance extracted by the second pump. Vaporization. The waste solvent treatment system according to item 1 or 3 of the scope of the patent application, further comprising: a fifth condenser connected to the evaporative heating device and used for condensing the medium boiling point substance vaporized by the evaporative heating device; and A seventh pump is connected to the fifth condenser to extract the middle boiling point substance condensed by the fifth condenser. The waste solvent processing system according to item 1 or 3 of the scope of patent application, further comprising: a second condenser connected to the storage tank and used to cool the low-boiling substance discharged from the storage tank; and a first Five pumps are connected to the second condenser to maintain the operating pressure of the waste solvent treatment system. The waste solvent treatment system according to item 1 of the scope of the patent application, wherein the medium boiling point material includes a material selected from the group consisting of monomethyl ether propylene glycol, propylene glycol monomethyl ether ester, and 3-ethoxy Ethyl propionate, monoethanolamine, dimethyl fluorene, diethylene glycol monobutyl ether, N methylpyrrolidone, cyclohexanone, cyclopentanone, ethyl lactate, dimethylacetamide, triethanolamine, A group consisting of diethylene glycol monomethyl ether, N-methylformamide, and any combination thereof. The waste solvent treatment system according to item 1 of the scope of patent application, wherein the packed bed is a regular packing, a bulk packing, a tray, or any combination thereof. The waste solvent processing system according to item 1 of the patent application scope, wherein the evaporation heating device provides heat to the first space. The waste solvent treatment system according to item 1 of the scope of patent application, wherein the solid content of the mixture is between 0 wt% and 60 wt%. A method for treating a waste solvent, comprising: providing a mixture in the waste solvent processing system as described in item 1 of the scope of patent application, so that the mixture enters the first space through the first inlet; providing heat to the first space So that the mixture is distributed from the first space to the second space and the third space; the mixture is received by the evaporation heating device and the high-boiling point substance is concentrated; by the first connected to the evaporation heating device The first pump at the bottom draws out the high-boiling substance in the evaporation heating device; the second pump connected to the second bottom of the first space to the high pump in the first space The boiling point substance and the middle boiling point substance are extracted into the evaporation heating device; the first reboiler provides heat to the second space; and the third gang is connected to the third bottom of the second space. Pumping out the medium boiling point substance in the second space; condensing the low boiling point substance discharged from the third space by the first condenser connected to the third space; by connecting to the first condensation Organ The storage tank stores the low boiling point substance discharged from the first condenser; and the fourth pump connected to the storage tank draws out a part of the low boiling point substance in the storage tank, and separates another portion of the low boiling point substance in the storage tank. A part of the low boiling point substance is drawn back into the third space. The method for treating a waste solvent as described in item 12 of the scope of patent application, further comprising: by means of a preheater connected to the third pump, the middle boiling point substance extracted from the third pump and the The mixture undergoes a heat exchange. After the mixture undergoes the heat exchange, it enters the waste solvent treatment system through the first inlet. The method for treating a waste solvent as described in item 12 of the scope of patent application, further comprising: cooling a medium boiling point substance in a vapor phase in the second space by connecting a third condenser connected to the second space, The medium-boiling point substance performs a heat exchange with the mixture, wherein the mixture enters the waste solvent treatment system through the first inlet after the heat exchange; the fourth condenser, which is connected to one of the third condenser, condenses the The medium boiling point substance after the third condenser is cooled; and the medium boiling point substance after being condensed by the fourth condenser is drawn out through a sixth pump connected to one of the fourth condensers. The method for treating a waste solvent according to item 12 of the scope of patent application, further comprising: condensing the medium boiling point substance in the vapor phase in the second space by a fourth condenser connected to the second space; and From the sixth pump connected to one of the fourth condensers, the medium-boiling point substance condensed by the fourth condenser is extracted. The method for treating a waste solvent according to item 12 or 14 of the scope of patent application, further comprising: providing heat to the first space through a second reboiler, and extracting the middle boiling point extracted by the second pump. The substance is vaporized. The method for treating a waste solvent according to item 12 or 14 of the scope of the patent application, further comprising: condensing the medium-boiling point substance vaporized by the evaporation heating device through a fifth condenser connected to the evaporation heating device; and With a seventh pump connected to the fifth condenser, the medium boiling point substance condensed by the fifth condenser is drawn out. The method for treating a waste solvent according to item 12 or 14 of the scope of patent application, further comprising: cooling the low-boiling substance discharged from the storage tank by the second condenser connected to the storage tank; and By the fifth pump connected to the second condenser, the operating pressure of the waste solvent treatment system is maintained. The method for treating a waste solvent according to item 12 of the scope of patent application, further comprising providing heat to the first space by the evaporation heater. The method for treating a waste solvent according to item 12 of the application, wherein the solid content of the mixture is between 0 wt% and 60 wt%.