SEMI-G5-grade high-purity NMP (N-Methyl Pyrrolidone) production process and system

Abstract

The invention provides a production process of SEMI-G5-grade high-purity NMP (N-Methyl Pyrrolidone), which is characterized in that metal ions, magnetic foreign / non-magnetic foreign particulate matters and the like of conventional industrial-grade NMP are completely removed by adopting a multi-section rectification, resin adsorption and precise filtration process, so that the SEMI-G5-grade NMP reaches the SEMI-G5 grade in an ultra-clean high-purity reagent; and the use requirements on the ultra-clean high-purity NMP in the fields of semiconductors, integrated circuits and novel display are met.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of NMP production, and in particular to a SEMI-G5 level high-purity NMP production process and system. BACKGROUND

[0002] N-methyl pyrrolidone, abbreviated as NMP, belongs to nitrogen heterocyclic compounds and has excellent physical and chemical properties. The NMP has a high boiling point, strong polarity, low viscosity, small corrosion, large solubility, low volatility, good stability, biodegradability and easy recovery, is widely applied to the fields of lithium batteries, photovoltaics, semiconductors and new display fields, is a high-quality and indispensable organic solvent, and is widely applied to the fields of petroleum chemical industry, pesticides, medicines and electronic materials.

[0003] At present, a mainstream domestic industrial-grade NMP production process is as follows: raw material BDO is dehydrogenated in a dehydrogenation reactor to generate GBL (r-butyrolactone) intermediate product, the GBL is reacted with monomethylamine or amine water under high temperature and high pressure to generate NMP, and then the NMP is subjected to rectification and dehydration and heavy component removal to obtain the final NMP product. The process can purify the NMP to 99.9% and remove most of the free amine and metal ions in the NMP, thereby meeting the requirements of the lithium battery industry for the NMP solvent. However, since the process is simple rectification and purification, the metal ions and small particles in the product cannot be completely removed, so that the requirements of the high-end wet electronic chemical field such as the integrated circuit, semiconductor and display panel industry for the ultra-clean high-purity reagent cannot be met. SUMMARY

[0004] In view of the problems in the prior art, the application provides a SEMI-G5 level high-purity NMP production process and system, so as to solve the technical problem that, in the prior art, simple rectification and purification cannot completely remove the metal ions and small particles in the product, so that the requirements of the high-end wet electronic chemical field such as the integrated circuit, semiconductor and display panel industry for the ultra-clean high-purity reagent cannot be met.

[0005] The application provides a SEMI-G5 level high-purity NMP production process, which comprises the following steps:

[0006] S1, a part of raw material NMP in an NMP raw material tank is sequentially sent into an NMP collecting tank through a preheater and a first cooler, and another part of the raw material is sent into a first rectification tower through the preheater to be rectified to form a first rectification gas phase and a first rectification liquid phase, the first rectification gas phase is condensed through a first condenser, the first rectification gas phase which is not condensed is sent into a second condenser until being condensed, the condensed first rectification gas phase is returned to the first rectification tower through a first reflux tank, and the first rectification liquid phase is heated and warmed through a first reboiler, and a first rectification light component is output from the first rectification tower;

[0007] S2, the first rectification light component is sent into a second rectification tower to form a second rectification gas phase and a second rectification liquid phase, the second rectification gas phase is condensed by a third condenser, the uncondensed second rectification gas phase is sent into a fourth condenser until condensation, part of the condensed second rectification gas phase is sent into the NMP collecting tank through the preheater and the first cooler in turn, another part of the second rectification gas phase returns to the second rectification tower through a second reflux tank, and the second rectification liquid phase is heated by a second reboiler to output a second rectification bottom liquid, and the second rectification bottom liquid is sent into a first tower kettle;

[0008] S3, the second rectification bottom liquid is pumped from the first tower kettle into a second tower kettle by a feed pump, and the second rectification bottom liquid is sent into a third reboiler to form a third gas phase, the third gas phase is sent into a third rectification tower to form a third rectification gas phase, the third rectification gas phase is condensed in a fifth condenser, if not condensed, the third rectification gas phase is continuously sent into a sixth condenser to condense, otherwise, part of the third rectification liquid phase formed after condensation is sent into the second cooler, and is sent into a first NMP buffer tank, an NMP waste liquid buffer tank and an unqualified NMP buffer tank according to quality respectively, and another part of the third rectification liquid phase returns to the third rectification tower;

[0009] S4, the NMP liquid in the first NMP buffer tank is sent into the NMP collecting tank, is condensed through a seventh condenser, is sequentially sent into a first resin tank and a second resin tank, and is then sent into a second NMP buffer tank, and then the NMP liquid in the second NMP buffer tank is sequentially sent into a heat exchanger, a third resin tank, a fourth resin tank and an NMP finished product tank, and the NMP liquid in the NMP finished product tank is sent into a precision filter to output qualified NMP.

[0010] Optionally, before step S1, the method comprises:

[0011] The adsorbents in the first resin tank, the second resin tank, the third resin tank and the fourth resin tank are sequentially cleaned by using ultrapure water, hydrochloric acid aqueous solution, ultrapure water and tetramethylammonium hydroxide aqueous solution, and the metal ion content of which is less than 0.01 ppb.

[0012] Optionally, the adsorbent comprises:

[0013] An ion exchange resin is used.

[0014] Optionally, the precision filter comprises:

[0015] A three-stage precision filter is used, and the filter particle sizes are 0.5 μm, 0.1 μm and 0.05 μm respectively.

[0016] The application further provides a high-purity NMP production system of SEMI-G5 level, which comprises:

[0017] The pretreatment module is used to sequentially send a portion of the NMP raw material from the NMP raw material tank to the NMP collection tank through a preheater and a first cooler, and another portion of the raw material enters the first distillation column through the preheater to form a first distillation vapor phase and a first distillation liquid phase. The first distillation vapor phase is condensed through a first condenser, and the uncondensed first distillation vapor phase is sent to a second condenser until condensation. The condensed first distillation vapor phase is returned to the first distillation column through a first reflux tank, and the first distillation liquid phase is heated by a first reboiler to raise its temperature. The first distillation light component is output from the first distillation column.

[0018] The first distillation module feeds the first light distillation component into the second distillation column for distillation to form a second distillation vapor phase and a second distillation liquid phase. The second distillation vapor phase is condensed by the third condenser. The uncondensed second distillation vapor phase is fed into the fourth condenser until it is condensed. A portion of the condensed second distillation vapor phase is fed into the NMP collection tank through the preheater and the first cooler in sequence. The other portion of the second distillation vapor phase is returned to the second distillation column via the second reflux tank. The second distillation liquid phase is heated by the second reboiler to output the second distillation bottom liquid. The second distillation bottom liquid is fed into the first column bottom tank.

[0019] The second distillation module is used to pump the second distillation bottom liquid from the first column bottom tank into the second column bottom tank using a feed pump, and send the second distillation bottom liquid to the third reboiler for heating to form a third gas phase. The third gas phase is sent to the third distillation column for distillation to form a third distillation gas phase. The third distillation gas phase enters the fifth condenser for condensation. If it does not condense, the third distillation gas phase is sent to the sixth condenser for condensation. Otherwise, a portion of the condensed third distillation liquid phase is sent to the second cooler and, according to quality, sent to the first NMP buffer tank, the NMP waste liquid buffer tank, and the unqualified NMP buffer tank respectively. The other portion of the third distillation liquid phase is returned to the third distillation column.

[0020] The precision filtration module is used to send the NMP liquid from the first NMP buffer tank into the NMP collection tank. After being condensed by the seventh condenser, it sequentially enters the first resin tank and the second resin tank before being sent to the second NMP buffer tank. The NMP liquid from the second NMP buffer tank is then sequentially sent to the heat exchanger, the third resin tank, the fourth resin tank, and the NMP finished product tank. Finally, the NMP liquid in the NMP finished product tank is sent to the precision filter to output qualified NMP.

[0021] Optionally, before the preprocessing module, the following is included:

[0022] The pretreatment process module is used to sequentially clean the adsorbents in the first resin tank, the second resin tank, the third resin tank, and the fourth resin tank using ultrapure water with metal ions all less than 0.01 ppb, hydrochloric acid aqueous solution, ultrapure water, and tetramethylammonium hydroxide aqueous solution.

[0023] Compared with the prior art, the present invention:

[0024] This patent employs a multi-stage distillation + resin adsorption + precision filtration process to completely remove metal ions, magnetic / non-magnetic particles, and other contaminants from conventional industrial-grade NMP, achieving the SEMI-G5 level of ultra-clean high-purity reagents. This meets the requirements for ultra-clean high-purity NMP in the semiconductor, integrated circuit, and new display fields. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0028] Figure 2 This is a schematic diagram of the modular process of the method of the present invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. NMP feed tank; 2. Preheater; 3. First cooler; 4. First distillation column; 5. First reboiler; 6. First condenser; 7. Second condenser; 8. First reflux tank; 9. Second distillation column; 10. Second reboiler; 11. Third condenser; 12. Fourth condenser; 13. Second reflux tank; 14. First column bottom tank; 15. Third distillation column; 16. Second column bottom tank; 17. Third reboiler; 18. Fifth condenser; 9. Sixth condenser; 20. Second cooler; 21. First NMP buffer tank; 22. NMP waste liquid buffer tank; 23. Non-conforming NMP buffer tank; 24. NMP collection tank; 25. Seventh condenser; 26. First resin tank; 27. Second resin tank; 28. Second NMP buffer tank; 29. ​​Heat exchanger; 30. Third resin tank; 31. Fourth resin tank; 32. NMP finished product tank; 33. Precision filter; 34. Feed pump. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other implementation cases obtained by those skilled in the art without creative effort are within the scope of protection of this application. Functional units with the same reference numerals in the examples of this invention have the same and similar structures and functions.

[0032] See Figure 1 and Figure 2 This invention provides a production process for SEMI-G5 grade high-purity NMP, comprising:

[0033] S1. A portion of the NMP raw material in the NMP raw material tank 1 is sequentially fed into the NMP collection tank 24 through the preheater 2 and the first cooler 3. Another portion of the raw material is fed into the first distillation column 4 through the preheater 2 to form a first distillation vapor phase and a first distillation liquid phase. The first distillation vapor phase is condensed through the first condenser 6. The uncondensed first distillation vapor phase is sent to the second condenser 7 until it is condensed. The condensed first distillation vapor phase is returned to the first distillation column 4 through the first reflux tank 8, and the first distillation liquid phase is heated by the first reboiler 5. The first distillation light component is output from the first distillation column 4.

[0034] S2. The first distillation light component is fed into the second distillation column 9 for distillation to form a second distillation vapor phase and a second distillation liquid phase. The second distillation vapor phase is condensed by the third condenser 11. The uncondensed second distillation vapor phase is fed into the fourth condenser 12 until condensation. A portion of the condensed second distillation vapor phase is fed into the NMP collection tank 24 through the preheater 2 and the first cooler 3 in sequence. The other portion of the second distillation vapor phase is returned to the second distillation column 9 through the second reflux tank 13 and the second distillation liquid phase is heated by the second reboiler 10 to output the second distillation bottom liquid. The second distillation bottom liquid is fed into the first column bottom tank 14.

[0035] S3. The second distillation bottom liquid is pumped from the first column bottom tank 14 into the second column bottom tank 16 using the feed pump 34. The second distillation bottom liquid is then sent to the third reboiler 17 for heating to form the third gas phase. The third gas phase is then sent to the third distillation column 15 for distillation to form the third distillation gas phase. The third distillation gas phase enters the fifth condenser 18 for condensation. If it does not condense, the third distillation gas phase is sent to the sixth condenser 19 for condensation. Otherwise, a portion of the condensed third distillation liquid phase is sent to the second cooler 20 and, according to quality, to the first NMP buffer tank 21, the NMP waste liquid buffer tank 22, and the unqualified NMP buffer tank 23. The other portion of the third distillation liquid phase is returned to the third distillation column 15.

[0036] S4. The NMP liquid in the first NMP buffer tank 21 is sent to the NMP collection tank 24. After being condensed by the seventh condenser 25, it enters the first resin tank 26 and the second resin tank 27 in sequence and then enters the second NMP buffer tank 28. The NMP liquid in the second NMP buffer tank 28 is then sent to the heat exchanger 29, the third resin tank 30, the fourth resin tank 31 and the NMP finished product tank 32 in sequence. The NMP liquid in the NMP finished product tank 32 is sent to the precision filter 33 to output qualified NMP.

[0037] In this embodiment, S1, a portion of the NMP raw material in the NMP raw material tank 1 is sequentially fed into the NMP collection tank 24 through the preheater 2 and the first cooler 3. Considering the rational use of the system's waste heat, the heat source of the preheater 2 can be provided by the second distillation vapor phase of the second reflux tank 13. Another portion of the raw material is preheated by the preheater 2 and then enters the first distillation column 4 for distillation to form a first distillation vapor phase and a first distillation liquid phase. The first distillation vapor phase is condensed by the first condenser 6. The uncondensed first distillation vapor phase is sent to the second condenser 7 until condensation. The condensed first distillation vapor phase is returned to the first distillation column 4 through the first reflux tank 8. The remaining part is discharged as wastewater and the first distillation liquid phase is heated by the first reboiler 5. The first distillation light component is output from the first distillation column 4.

[0038] S3. The second distillation bottom liquid is pumped from the first column bottom tank 14 into the second column bottom tank 16 using the feed pump 34. The second distillation bottom liquid is then sent to the third reboiler 17 for heating to form the third gas phase. The third gas phase is then sent to the third distillation column 15 for distillation to form the third distillation gas phase. The third distillation gas phase enters the fifth condenser 18 for condensation. If it does not condense, the third distillation gas phase is sent to the sixth condenser 19 for condensation. Otherwise, a portion of the condensed third distillation liquid phase is sent to the second cooler 20 and, according to quality, to the first NMP buffer tank 21, the NMP waste liquid buffer tank 22, and the unqualified NMP buffer tank 23. The other portion of the third distillation liquid phase is returned to the third distillation column 15.

[0039] S4. The NMP liquid in the first NMP buffer tank 21 is sent to the NMP collection tank 24. After being condensed by the seventh condenser 25, it enters the first resin tank 26 and the second resin tank 27 in sequence and is then sent to the second buffer tank. The NMP liquid in the second buffer tank is then sent to the heat exchanger 29, the third resin tank 30, the fourth resin tank 31 and the NMP finished product tank 32 in sequence. The NMP liquid in the NMP finished product tank 32 is then sent to the precision filter 33 to output qualified NMP.

[0040] Steps S1, S2 and S3 mainly employ distillation processes, the purpose of which is to remove most of the metal ions and particulate matter. In step S2, the remaining trace metal ions are removed by the ion exchange resin adsorption process of the resin tank, and the residual micron-sized particulate matter is removed by the precision filtration process of the precision filter 33.

[0041] In another embodiment, prior to step S1, the following is included:

[0042] The adsorbents in the first resin tank 26, the second resin tank 27, the third resin tank 30, and the fourth resin tank 31 were cleaned sequentially using ultrapure water with metal ions all less than 0.01 ppb, hydrochloric acid aqueous solution, ultrapure water, and tetramethylammonium hydroxide aqueous solution.

[0043] Cleaning the adsorbent can activate it, thereby removing metal ions and particulate matter from NMP and improving its purity.

[0044] In another embodiment, the adsorbent comprises:

[0045] Ion exchange resin is used.

[0046] In another embodiment, the precision filter 33 includes:

[0047] A three-stage precision filter 33 is used, with filter particle sizes of 0.5μm, 0.1μm, and 0.05μm, respectively.

[0048] The precision filter 33 adopts a three-stage filtration method. The product passes through three precision filters of 0.5um, 0.1um and 0.05um respectively, which gradually reduces the size and content of particulate matter in the product. The precision filter 33 uses PFA skeleton + PTFE filter element material.

[0049] This invention employs a multi-stage distillation + resin adsorption + precision filtration process to completely remove metal ions, magnetic / non-magnetic particles, and other contaminants from conventional industrial-grade NMP, achieving a SEMI-G5 level of ultra-clean high-purity reagents. This meets the requirements of the semiconductor, integrated circuit, and new display industries for ultra-clean high-purity NMP.

[0050] This invention also provides a SEMI-G5 level high-purity NMP production system, comprising:

[0051] The pretreatment module is used to send a portion of the NMP raw material in the NMP raw material tank 1 into the NMP collection tank 24 through the preheater 2 and the first cooler 3 in sequence, and another portion of the raw material enters the first distillation column 4 through the preheater 2 for distillation to form a first distillation vapor phase and a first distillation liquid phase. The first distillation vapor phase is condensed through the first condenser 6. The uncondensed first distillation vapor phase is sent to the second condenser 7 until it is condensed. The condensed first distillation vapor phase is returned to the first distillation column 4 through the first reflux tank 8, and the first distillation liquid phase is heated by the first reboiler 5. The first distillation light component is output from the first distillation column 4.

[0052] The first distillation module feeds the first distilled light component into the second distillation column 9 for distillation to form a second distilled vapor phase and a second distilled liquid phase. The second distilled vapor phase is condensed by the third condenser 11. The uncondensed second distilled vapor phase is fed into the fourth condenser 12 until condensation. A portion of the condensed second distilled vapor phase is fed into the NMP collection tank 24 through the preheater 2 and the first cooler 3 in sequence. The other portion of the second distilled vapor phase is returned to the second distillation column 9 via the second reflux tank 13. The second distilled liquid phase is heated by the second reboiler 10 to output the second distilled bottom liquid. The second distilled bottom liquid is fed into the first column bottom tank 14.

[0053] The second distillation module is used to pump the second distillation bottom liquid from the first column bottom tank 14 into the second column bottom tank 16 using a feed pump 34, and then send the second distillation bottom liquid to the third reboiler 17 for heating to form a third gas phase. The third gas phase is sent to the third distillation column 15 for distillation to form a third distillation gas phase. The third distillation gas phase enters the fifth condenser 18 for condensation. If it does not condense, the third distillation gas phase is sent to the sixth condenser 19 for condensation. Otherwise, a portion of the condensed third distillation liquid phase is sent to the second cooler 20 and, according to quality, to the first NMP buffer tank 21, the NMP waste liquid buffer tank 22, and the unqualified NMP buffer tank 23. The other portion of the third distillation liquid phase is returned to the third distillation column 15.

[0054] The precision filtration module is used to send the NMP liquid from the first NMP buffer tank 21 into the NMP collection tank 24, and after being condensed by the seventh condenser 25, it sequentially enters the first resin tank 26 and the second resin tank 27 and then enters the second NMP buffer tank 28. The NMP liquid from the second NMP buffer tank 28 is then sequentially sent to the heat exchanger 29, the third resin tank 30, the fourth resin tank 31 and the NMP finished product tank 32, and the NMP liquid in the NMP finished product tank 32 is sent to the precision filter 33 to output qualified NMP.

[0055] In another embodiment, preceding the preprocessing module, the following is included:

[0056] The pretreatment process module is used to sequentially clean the adsorbents in the first resin tank 26, the second resin tank 27, the third resin tank 30, and the fourth resin tank 31 with ultrapure water containing metal ions all less than 0.01 ppb, hydrochloric acid aqueous solution, ultrapure water, and tetramethylammonium hydroxide aqueous solution.

[0057] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A production process for SEMI-G5 grade high-purity NMP, characterized in that, include: S1. A portion of the NMP raw material in the NMP raw material tank is sequentially fed into the NMP collection tank through a preheater and a first cooler. Another portion of the raw material is fed into the first distillation column through the preheater to form a first distillation vapor phase and a first distillation liquid phase. The first distillation vapor phase is condensed through the first condenser. The uncondensed first distillation vapor phase is sent to the second condenser until it is condensed. The condensed first distillation vapor phase is returned to the first distillation column through the first reflux tank, and the first distillation liquid phase is heated by the first reboiler. The first distillation light component is output from the first distillation column. S2. The first distillation light component is fed into the second distillation column for distillation to form a second distillation vapor phase and a second distillation liquid phase. The second distillation vapor phase is condensed through the third condenser. The uncondensed second distillation vapor phase is fed into the fourth condenser until it is condensed. A portion of the condensed second distillation vapor phase is fed into the NMP collection tank through the preheater and the first cooler in sequence. The other portion of the second distillation vapor phase is returned to the second distillation column through the second reflux tank. The second distillation liquid phase is heated by the second reboiler to output the second distillation bottom liquid. The second distillation bottom liquid is fed into the first column bottom tank. S3. The second distillation bottom liquid is pumped from the first column bottom tank into the second column bottom tank using a feed pump, and then sent to the third reboiler for heating to form the third gas phase. The third gas phase is sent to the third distillation column for distillation to form the third distillation gas phase. The third distillation gas phase enters the fifth condenser for condensation. If it does not condense, the third distillation gas phase is sent to the sixth condenser for condensation. Otherwise, a portion of the condensed third distillation liquid phase is sent to the second cooler and then sent to the first NMP buffer tank, the NMP waste liquid buffer tank, and the unqualified NMP buffer tank according to their quality. The other portion of the third distillation liquid phase is returned to the third distillation column. S4. The NMP liquid in the first NMP buffer tank is sent to the NMP collection tank. After being condensed by the seventh condenser, it enters the first resin tank and the second resin tank in sequence and then enters the second NMP buffer tank. The NMP liquid in the second NMP buffer tank is then sent to the heat exchanger, the third resin tank, the fourth resin tank and the NMP finished product tank in sequence. The NMP liquid in the NMP finished product tank is sent to the precision filter to output qualified NMP.

2. The SEMI-G5 grade high-purity NMP production process as described in claim 1, characterized in that, Before step S1, the following are included: The adsorbents in the first, second, third, and fourth resin tanks were cleaned sequentially using ultrapure water with metal ion concentrations all less than 0.01 ppb, hydrochloric acid aqueous solution, ultrapure water, and tetramethylammonium hydroxide aqueous solution.

3. The SEMI-G5 grade high-purity NMP production process as described in claim 2, characterized in that, The adsorbent comprises: Ion exchange resin is used.

4. The SEMI-G5 grade high-purity NMP production process as described in claim 1, characterized in that, The precision filter includes: It employs a three-stage precision filter with filter particle sizes of 0.5μm, 0.1μm, and 0.05μm, respectively.

5. A SEMI-G5 grade high-purity NMP production system, characterized in that, include: The pretreatment module is used to sequentially send a portion of the NMP raw material from the NMP raw material tank to the NMP collection tank through a preheater and a first cooler, and another portion of the raw material enters the first distillation column through the preheater to form a first distillation vapor phase and a first distillation liquid phase. The first distillation vapor phase is condensed through a first condenser, and the uncondensed first distillation vapor phase is sent to a second condenser until condensation. The condensed first distillation vapor phase is returned to the first distillation column through a first reflux tank, and the first distillation liquid phase is heated by a first reboiler to raise its temperature. The first distillation light component is output from the first distillation column. The first distillation module feeds the first light distillation component into the second distillation column for distillation to form a second distillation vapor phase and a second distillation liquid phase. The second distillation vapor phase is condensed by the third condenser. The uncondensed second distillation vapor phase is fed into the fourth condenser until it is condensed. A portion of the condensed second distillation vapor phase is fed into the NMP collection tank through the preheater and the first cooler in sequence. The other portion of the second distillation vapor phase is returned to the second distillation column via the second reflux tank. The second distillation liquid phase is heated by the second reboiler to output the second distillation bottom liquid. The second distillation bottom liquid is fed into the first column bottom tank. The second distillation module is used to pump the second distillation bottom liquid from the first column bottom tank into the second column bottom tank using a feed pump, and send the second distillation bottom liquid to the third reboiler for heating to form a third gas phase. The third gas phase is sent to the third distillation column for distillation to form a third distillation gas phase. The third distillation gas phase enters the fifth condenser for condensation. If it does not condense, the third distillation gas phase is sent to the sixth condenser for condensation. Otherwise, a portion of the condensed third distillation liquid phase is sent to the second cooler and, according to quality, sent to the first NMP buffer tank, the NMP waste liquid buffer tank, and the unqualified NMP buffer tank respectively. The other portion of the third distillation liquid phase is returned to the third distillation column. The precision filtration module is used to send the NMP liquid from the first NMP buffer tank into the NMP collection tank. After being condensed by the seventh condenser, it sequentially enters the first resin tank and the second resin tank before being sent to the second NMP buffer tank. The NMP liquid from the second NMP buffer tank is then sequentially sent to the heat exchanger, the third resin tank, the fourth resin tank, and the NMP finished product tank. Finally, the NMP liquid in the NMP finished product tank is sent to the precision filter to output qualified NMP.

6. The SEMI-G5 level high-purity NMP production system as described in claim 5, characterized in that, Prior to the preprocessing module, the following are included: The pretreatment process module is used to sequentially clean the adsorbents in the first resin tank, the second resin tank, the third resin tank, and the fourth resin tank using ultrapure water with metal ions all less than 0.01 ppb, hydrochloric acid aqueous solution, ultrapure water, and tetramethylammonium hydroxide aqueous solution.

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