CN117510390B - Method and system for removing free ammonia in NMP - Google Patents
Method and system for removing free ammonia in NMP Download PDFInfo
- Publication number
- CN117510390B CN117510390B CN202410021251.1A CN202410021251A CN117510390B CN 117510390 B CN117510390 B CN 117510390B CN 202410021251 A CN202410021251 A CN 202410021251A CN 117510390 B CN117510390 B CN 117510390B
- Authority
- CN
- China
- Prior art keywords
- nmp
- waste liquid
- free ammonia
- product
- liquid level
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 title claims abstract description 166
- 229910021529 ammonia Inorganic materials 0.000 title claims abstract description 83
- 238000000034 method Methods 0.000 title claims abstract description 33
- 239000007788 liquid Substances 0.000 claims abstract description 104
- 239000002699 waste material Substances 0.000 claims abstract description 64
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 51
- 238000005070 sampling Methods 0.000 claims abstract description 13
- 239000000203 mixture Substances 0.000 claims abstract description 11
- 238000010992 reflux Methods 0.000 claims abstract description 7
- 230000001276 controlling effect Effects 0.000 claims abstract description 4
- 230000001105 regulatory effect Effects 0.000 claims abstract description 4
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 239000000126 substance Substances 0.000 abstract description 6
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 56
- 239000002351 wastewater Substances 0.000 description 8
- 238000009835 boiling Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 150000003863 ammonium salts Chemical class 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000012510 hollow fiber Substances 0.000 description 2
- 229910000040 hydrogen fluoride Inorganic materials 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 238000005342 ion exchange Methods 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 150000007522 mineralic acids Chemical class 0.000 description 2
- 150000007524 organic acids Chemical class 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000009834 vaporization Methods 0.000 description 2
- 230000008016 vaporization Effects 0.000 description 2
- 229910001290 LiPF6 Inorganic materials 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 239000012776 electronic material Substances 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- -1 lithium hexafluorophosphate Chemical compound 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 239000000575 pesticide Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D207/00—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom
- C07D207/02—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D207/18—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having one double bond between ring members or between a ring member and a non-ring member
- C07D207/22—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having one double bond between ring members or between a ring member and a non-ring member with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D207/24—Oxygen or sulfur atoms
- C07D207/26—2-Pyrrolidones
- C07D207/263—2-Pyrrolidones with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms
- C07D207/267—2-Pyrrolidones with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to the ring nitrogen atom
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/10—Vacuum distillation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
- B01D3/143—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step
- B01D3/148—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step in combination with at least one evaporator
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
Abstract
Disclosed herein is a method and system for removing free ammonia from NMP, the method comprising: collecting NMP waste liquid to a waste liquid tank, so that the liquid level in the waste liquid tank reaches a preset liquid level smaller than the full liquid level; detecting the free ammonia content and the water content of NMP waste liquid; adding pure water into the waste liquid tank according to the free ammonia content of the NMP waste liquid to increase the water content of the NMP waste liquid to a first preset value; starting a vacuum pump to enable the vacuum degree of the rectifying tower to be a second preset value; starting an evaporator and a reboiler; delivering NMP waste liquid in the waste liquid tank to an evaporator; feeding the vaporized mixture of the evaporator to a feed section in a rectifying column; regulating the reflux quantity of water at the tower top, and controlling the temperature at the tower top to be a third preset value and the temperature in the tower to be a fourth preset value; collecting the bottom product of the rectifying tower, sampling and analyzing NMP purity, free ammonia content and water content of the product, wherein the free ammonia content of the product is less than or equal to 10ppm. The method can effectively remove free ammonia, does not need to add other substances except pure water, and is convenient for industrialized operation.
Description
Technical Field
The specification relates to the technical field of NMP rectification, in particular to a method and a system for removing free ammonia in NMP.
Background
N-methyl pyrrolidone (NMP) is a high-grade solvent with strong polarity and excellent performance, is nontoxic and harmless, and is widely applied to the fields of pesticides, medicines, electronic materials, new energy manufacturing and the like. At present, NMP is widely used as an excellent solvent in the production process of a positive pole piece by using PVDF (polyvinylidene fluoride) as a binder in the field of new energy manufacturing.
For production process reasons, the recovered NMP product contains, in addition to NMP (90-95 wt.%), a quantity of water (10-5 wt.%) and free ammonia (300-400 ppm). The free ammonia can be polymerized in the charge and discharge process, the conductivity of the electrolyte is reduced, and meanwhile, the substances react with LiPF6 (lithium hexafluorophosphate) to generate HF (hydrogen fluoride) which can influence the service life of the battery, so that the free ammonia belongs to impurities in a finished product, and the content of the free ammonia is required to be below 10ppm in the battery industry generally. In the NMP rectification process, how to remove free ammonia, improve NMP quality, eliminate the influence on battery quality, increase economic benefit and reduce environmental pollution becomes a problem to be solved urgently.
In the prior art, the free ammonia content is reduced by ion exchange through ion exchange fibers. As in patent CN116370988A, it is disclosed that secondary free ammonia removal is performed by a contactor of a heterogeneous hollow fiber membrane, which improves the free ammonia removal effect and ensures recovery rate in the NMP rectification process. However, the regeneration of the hollow fiber membrane and the control of the production efficiency and the production cost are difficult to realize.
In addition, in the prior art, organic acid or inorganic acid is added for neutralization, so that free ammonia is converted into ammonium salt, and then the free ammonia is removed in a tower kettle liquid discharge mode. As in patent CN116239514A, acid is added to adjust the pH value to be between 6.5 and 7.5 in the rectification process, so that free ammonia is converted into ammonium salt to be removed. However, the evaluation of the effect of the residue of exogenously added substances (such as organic or inorganic acids) in the product on the quality of the battery is complicated.
Disclosure of Invention
In view of the shortcomings of the prior art, it is an object of the present specification to provide a method and system for removing free ammonia from NMP that is effective in removing free ammonia, does not require the addition of substances other than pure water, and facilitates industrial operations.
To achieve the above object, embodiments of the present disclosure provide a method for removing free ammonia in NMP, comprising the steps of:
collecting NMP waste liquid to a waste liquid tank, so that the liquid level in the waste liquid tank reaches a preset liquid level; the predetermined liquid level is less than a full liquid level of the waste liquid tank;
detecting the free ammonia content and the water content of NMP waste liquid in the waste liquid tank;
adding pure water into the waste liquid tank according to the free ammonia content of the NMP waste liquid to increase the water content of the NMP waste liquid to a first preset value;
starting a vacuum pump connected with the rectifying tower to enable the vacuum degree of the rectifying tower to be a second preset value;
starting an evaporator and a reboiler which are connected with the rectifying tower;
delivering NMP waste liquid in the waste liquid tank to the evaporator;
feeding the vaporized mixture of the evaporator to a column-in-column feed section of the rectifying column;
regulating the reflux quantity of water at the top of the rectifying tower, and controlling the temperature at the top of the rectifying tower to be a third preset value and the temperature in the rectifying tower to be a fourth preset value;
and collecting a product at the bottom of the rectifying tower, and sampling and analyzing the NMP purity, the free ammonia content and the water content of the product, wherein the free ammonia content of the product is less than or equal to 10ppm.
As a preferred embodiment, the predetermined liquid level is 90% of the full liquid level.
In a preferred embodiment, the first predetermined value is 6% -10%.
As a preferable implementation mode, the second preset value is-91 kPa to-89 kPa.
In a preferred embodiment, the third predetermined value is 50 ℃ to 60 ℃.
In a preferred embodiment, the fourth predetermined value is 115 ℃ to 125 ℃.
As a preferred embodiment, when the free ammonia content of the NMP waste liquid is 100ppm, the first preset value is 6%, and the third preset value is 52-55 ℃.
As a preferred embodiment, when the free ammonia content of the NMP waste liquid is 500ppm, the first preset value is 10%, and the third preset value is 50-60 ℃.
As a preferred embodiment, the step of collecting the product at the bottom of the rectifying column comprises:
collecting a product at the bottom of the rectifying tower by using a product collecting tank, and performing sampling analysis when the liquid level in the product collecting tank reaches a first set liquid level;
after the product in the product collecting tank is qualified, inputting the product into a finished product storage tank;
when the liquid level in the finished product storage tank reaches a second set liquid level, the liquid level is used as a batch for sampling analysis, and the liquid level is qualified for production and use.
The present specification embodiment also provides a system for removing free ammonia from NMP for performing the method for removing free ammonia from NMP as described in any one of the embodiments above; the system comprises:
a waste liquid tank;
an evaporator connected to the waste liquid tank;
the evaporator is connected with the middle part of the rectifying tower;
the condenser, the vacuum pump and the wastewater tank are connected with the top of the rectifying tower, and the wastewater tank is used for collecting water and free ammonia separated from the top of the rectifying tower;
and the product collecting tank is used for collecting products at the bottom of the tower.
The beneficial effects are that:
according to the method for removing free ammonia in NMP, pure water is added according to the free ammonia content of NMP waste liquid, the water content of the NMP waste liquid is increased to a first preset value, the vacuum degree of a rectifying tower is controlled to be a second preset value, the temperature of the top of the tower is controlled to be a third preset value, the temperature in the tower is controlled to be a fourth preset value, and therefore the vaporized mixture in an evaporator is input into a feeding section of the rectifying tower, and due to the proper water content, vacuum degree and temperature, the free ammonia and water are utilized to form a low-boiling mixture, the free ammonia is separated from the top of the rectifying tower (the water can carry out redundant free ammonia from the top of the rectifying tower), so that the free ammonia content in a product produced at the bottom of the tower is ensured to be less than or equal to 10ppm.
Therefore, the method can effectively remove free ammonia in NMP, does not need to add other substances except pure water, does not influence the quality of the battery, has simple steps, and is convenient for industrialized operation.
Specific embodiments of the invention are disclosed in detail below with reference to the following description and drawings, indicating the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the invention are not limited in scope thereby.
Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments in combination with or instead of the features of the other embodiments.
It should be emphasized that the term "comprises/comprising" when used herein is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps or components.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained from these drawings without inventive faculty for a person skilled in the art.
FIG. 1 is a flow chart of steps of a method for removing free ammonia from NMP provided in this embodiment;
fig. 2 is a process flow diagram of a system for removing free ammonia from NMP provided in this embodiment.
Reference numerals illustrate:
1. a waste liquid tank; 2. an evaporator; 3. a rectifying tower; 31. a feed section in the column; 4. a condenser; 5. a vacuum pump; 6. a waste water tank; 7. a reboiler; 8. a product collection tank; 9. a finished product storage tank; 10. a feed pump; 11. a return line; 12. a collection pipe; 13. a cooler; 14. a buffer tank; 15. a discharge pump; 16. a temperature controller; 17. a valve; 18. a pressure gauge.
Detailed Description
In order to make the technical solution of the present invention better understood by those skilled in the art, the technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, shall fall within the scope of the invention.
It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
Please refer to fig. 1. Embodiments of the present application provide a method for removing free ammonia from NMP, comprising the steps of:
step S10: NMP waste liquid is collected to the waste liquid tank 1, so that the liquid level in the waste liquid tank 1 reaches a preset liquid level.
Wherein the predetermined liquid level is smaller than the full liquid level of the waste liquid tank 1, thereby reserving space for adding pure water in the subsequent step. Preferably, the predetermined liquid level is 90% of the full liquid level.
Step S20: the free ammonia content and the water content of the NMP waste liquid in the waste liquid tank 1 were detected.
Specifically, the NMP waste liquid in this embodiment mainly contains NMP, water and free ammonia. Wherein the water content is about 3% -5%, and the free ammonia content is higher and can reach more than 100 ppm. In addition, the pH value of NMP waste liquid can be detected.
Step S30: according to the free ammonia content of the NMP waste liquid, pure water is added into the waste liquid tank 1, so that the water content of the NMP waste liquid is increased to a first preset value.
Wherein, the first preset value is preferably 6% -10%. By increasing the water content, the subsequent removal of free ammonia is facilitated at the top of the rectifying tower 3 by taking away a large amount of free ammonia with a sufficient amount of water, thereby achieving the purpose of removing free ammonia.
Step S40: and starting a vacuum pump 5 connected with the rectifying tower 3 to enable the vacuum degree of the rectifying tower 3 to be a second preset value.
In the present embodiment, in order to remove free ammonia at the top of the rectifying tower 3, a predetermined amount of water is required, and the vacuum degree of the rectifying tower 3 needs to be satisfied. Wherein the second preset value is preferably-91 kPa to-89 kPa, namely-90+/-1 kPa. Moreover, the vacuum degree meeting the requirement can reduce the boiling point of NMP, so that NMP is produced from the bottom of the tower.
Step S50: the evaporator 2 and reboiler 7 connected to the rectifying column 3 are started.
Wherein the evaporator 2 and the reboiler 7 constitute a heating mechanism of the rectifying column 3. The evaporator 2 serves to ensure that the vaporized mixture is fed to the column feed section 31 of the rectification column 3, the temperature of the middle section of the rectification column 3 being maintained to some extent. Reboiler 7 is connected to the bottom of rectifying column 3, and rectifying column 3 may be heated from the bottom of the column to help maintain the temperature of the middle section and the top of rectifying column 3. Reboiler 7 may be connected to a temperature controller 16 and a pressure gauge 18 to facilitate control of the temperature of reboiler 7 and monitoring of the pressure within reboiler 7.
Step S60: the NMP waste liquid in the waste liquid tank 1 is sent to the evaporator 2.
Specifically, a feed pump 10 may be disposed between the waste liquid tank 1 and the evaporator 2, and the feed pump 10 is used to power the NMP waste liquid, so that the NMP waste liquid is smoothly transferred from the waste liquid tank 1 to the evaporator 2.
Step S70: the vaporized mixture of the evaporator 2 is fed to the column-in-column feed section 31 of the rectification column 3.
Wherein the vaporization mixture is NMP waste liquid added with pure water, and the components mainly comprise NMP, water and free ammonia. Wherein the content of free ammonia is still high and the content of water is a first predetermined value. After the vaporized mixture enters the feed section 31 of the column, water can carry free ammonia out of the top of the column and NMP is produced from the bottom of the column.
Step S80: the reflux amount of water at the top of the rectifying tower 3 is regulated, the temperature at the top of the tower is controlled to be a third preset value, and the temperature in the tower is controlled to be a fourth preset value.
In the present embodiment, in order to remove free ammonia at the top of the rectifying column 3, a predetermined amount of water and a vacuum degree that satisfies the requirement are required, and the temperature of the rectifying column 3 is also required to satisfy the requirement. Wherein the third preset value is preferably 50-60 ℃. Further, the third predetermined value is preferably 52 ℃ to 58 ℃. The fourth predetermined value is preferably 115 ℃ to 125 ℃ below the boiling point of NMP. Further, the fourth predetermined value is preferably 117 ℃ to 123 ℃.
As shown in fig. 2, the top of the rectifying tower 3 is connected with a reflux pipeline 11, the reflux pipeline 11 is provided with a condenser 4, and the condenser 4 is also connected with a vacuum pump 5. The return line 11 is also connected to the waste water tank 6 via a collecting line 12, the waste water tank 6 being able to collect water and free ammonia separated off at the top of the column. By adjusting the reflux quantity of water, the evaporator 2 and the reboiler 7, the control of the temperature at the top of the tower and the temperature in the tower can be realized, and the control of the water content in the step S30 and the control of the vacuum degree in the step S40 are combined, so that the free ammonia can be removed from the top of the rectifying tower 3, the content of the free ammonia in the product at the bottom of the tower is lower, and the requirements are met.
In the present embodiment, the temperature controllers 16 may be provided at the bottom, in the column, and at the top of the rectifying column 3, respectively, so that the bottom temperature, in-column temperature, and top temperature of the rectifying column 3 can be assisted in control.
Step S90: collecting the product at the bottom of the rectifying tower 3, and sampling and analyzing the NMP purity, the free ammonia content and the water content of the product, wherein the free ammonia content of the product is less than or equal to 10ppm.
Specifically, step S90 specifically includes:
step S901: collecting a product at the bottom of the rectifying tower 3 by using a product collecting tank 8, and performing sampling analysis when the liquid level in the product collecting tank 8 reaches a first set liquid level;
step S902: after the product in the product collection tank 8 is qualified, inputting the product into a finished product storage tank 9;
step S903: when the liquid level in the finished product storage tank 9 reaches the second set liquid level, the liquid level is taken as a batch for sampling analysis, and the liquid level is qualified for production.
The product collecting tank 8 can be used as an intermediate tank, and sampling analysis can ensure that the obtained product meets the requirements of production and use. Once the result of the sampling analysis does not meet the requirement, the first, second, third or fourth predetermined values in the respective steps need to be adjusted until the result meets the requirement. If the result of the sampling analysis meets the requirements, the operation parameters (including the feeding amount of the evaporator 2, the generated steam amount and the like) are stabilized, the first, second, third and fourth predetermined values are kept unchanged, and the normal output is achieved by using the steps.
In step S902, after the product in the product collection tank 8 is acceptable, the product is pumped into the finished product storage tank 9 by a filter pump through a precision filter.
In a specific embodiment, when the free ammonia content of the NMP waste liquid measured in the step S20 is 100ppm, the first preset value is controlled to be 6% in the step S30, and the third preset value is controlled to be 52-55 ℃ in the step S80, and the product at the bottom of the tower meets the requirement.
In another specific embodiment, when the free ammonia content of the NMP waste liquid measured in the step S20 is 500ppm, the first preset value is controlled to be 10% in the step S30, and the third preset value is controlled to be 50-60 ℃ in the step S80, and the product at the bottom of the tower meets the requirement.
According to the method for removing free ammonia in NMP, pure water is added according to the free ammonia content of NMP waste liquid, the water content of NMP waste liquid is increased to a first preset value, the vacuum degree of the rectifying tower 3 is controlled to be a second preset value, the temperature at the top of the tower is controlled to be a third preset value, the temperature in the tower is controlled to be a fourth preset value, so that after the vaporization mixture in the evaporator 2 is input into the feeding section 31 in the rectifying tower 3, a low-boiling mixture is formed by the free ammonia and water due to the proper water content, the vacuum degree and the temperature, the free ammonia is separated from the top of the rectifying tower 3 (the water can carry out redundant free ammonia from the top of the rectifying tower 3), and the free ammonia content in a product produced at the bottom of the tower is ensured to be less than or equal to 10ppm.
Therefore, the method can effectively remove free ammonia in NMP, does not need to add other substances except pure water, does not influence the quality of the battery, has simple steps, and is convenient for industrialized operation.
Referring to fig. 2, fig. 2 is a schematic structural diagram of an embodiment of a system for removing free ammonia from NMP according to the present application, and it should be noted that the system of the present embodiment may perform the steps of the above method, and details of the related content refer to the above method section and will not be described herein.
In this embodiment, the system embodiment corresponds to the method embodiment, which can solve the technical problem solved by the method embodiment, and accordingly achieve the technical effect of the method embodiment, and the detailed description of the present application is omitted herein.
As shown in fig. 2, the system for removing free ammonia in NMP provided in this embodiment includes a waste liquid tank 1, an evaporator 2, a rectifying column 3, a condenser 4, a vacuum pump 5, a waste water tank 6, a reboiler 7, and a product collecting tank 8.
Wherein the evaporator 2 is connected with the waste liquid tank 1. The evaporator 2 is connected with the middle part of the rectifying tower 3. The condenser 4, the vacuum pump 5 and the wastewater tank 6 are all connected with the top of the rectifying tower 3. The wastewater tank 6 is used for collecting water and free ammonia separated from the top of the column. The reboiler 7 and the product collection tank 8 are connected with the bottom of the rectifying tower 3. The product collection tank 8 is used to collect the bottom product.
Specifically, a cooler 13 is connected to the bottom of the rectifying tower 3 for cooling the product. The buffer tank 14 is arranged between the cooler 13 and the product collecting tank 8, so that pressure fluctuation can be buffered, the system can work more stably, the non-uniformity of the flow of the product discharge pipeline is reduced, and the generation of excessive flow is avoided, so that the process flow is adapted to the requirement of a process flow. A discharge pump 15 is provided between the buffer tank 14 and the product collection tank 8 for pumping the product from the buffer tank 14 to the product collection tank 8.
As shown in fig. 2, valves 17 may be provided at various places in the system for removing free ammonia in NMP (e.g., between the effluent tank 1 and the feed pump 10, between the feed pump 10 and the evaporator 2, on the return line 11, etc.), for controlling the opening and closing of the piping, so as to facilitate the normal operation and routine maintenance of the system.
It should be noted that, in the description of the present specification, the terms "first," "second," and the like are used for descriptive purposes only and to distinguish between similar objects, and there is no order of preference therebetween, nor should it be construed as indicating or implying relative importance. In addition, in the description of the present specification, unless otherwise indicated, the meaning of "a plurality" is two or more.
Any numerical value recited herein includes all values of the lower and upper values that are incremented by one unit from the lower value to the upper value, as long as there is a separation of at least two units between any lower value and any higher value. For example, if it is stated that the number of components or the value of a process variable (e.g., temperature, pressure, time, etc.) is from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, then the purpose is to explicitly list such values as 15 to 85, 22 to 68, 43 to 51, 30 to 32, etc. in this specification as well. For values less than 1, one unit is suitably considered to be 0.0001, 0.001, 0.01, 0.1. These are merely examples that are intended to be explicitly recited in this description, and all possible combinations of values recited between the lowest value and the highest value are believed to be explicitly stated in the description in a similar manner.
Unless otherwise indicated, all ranges include endpoints and all numbers between endpoints. "about" or "approximately" as used with a range is applicable to both endpoints of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30," including at least the indicated endpoints.
All articles and references, including patent applications and publications, disclosed herein are incorporated by reference for all purposes. The term "consisting essentially of …" describing a combination shall include the identified element, ingredient, component or step as well as other elements, ingredients, components or steps that do not substantially affect the essential novel features of the combination. The use of the terms "comprises" or "comprising" to describe combinations of elements, components, or steps herein also contemplates embodiments consisting essentially of such elements, components, or steps. By using the term "may" herein, it is intended that any attribute described as "may" be included is optional.
Multiple elements, components, parts or steps can be provided by a single integrated element, component, part or step. Alternatively, a single integrated element, component, part or step may be divided into separate plural elements, components, parts or steps. The disclosure of "a" or "an" to describe an element, component, section or step is not intended to exclude other elements, components, sections or steps.
It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and many applications other than the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the present teachings should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated herein by reference for the purpose of completeness. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to forego such subject matter, nor should the inventors regard such subject matter as not be considered to be part of the disclosed subject matter.
Claims (5)
1. A method for removing free ammonia from NMP comprising the steps of:
collecting NMP waste liquid to a waste liquid tank, so that the liquid level in the waste liquid tank reaches a preset liquid level; the predetermined liquid level is less than a full liquid level of the waste liquid tank;
detecting the free ammonia content and the water content of NMP waste liquid in the waste liquid tank;
adding pure water into the waste liquid tank according to the free ammonia content of the NMP waste liquid to increase the water content of the NMP waste liquid to a first preset value; the first preset value is 6% -10%;
starting a vacuum pump connected with the rectifying tower to enable the vacuum degree of the rectifying tower to be a second preset value; the second preset value is-91 kPa to-89 kPa;
starting an evaporator and a reboiler which are connected with the rectifying tower;
delivering NMP waste liquid in the waste liquid tank to the evaporator;
feeding the vaporized mixture of the evaporator to a column-in-column feed section of the rectifying column;
regulating the reflux quantity of water at the top of the rectifying tower, and controlling the temperature at the top of the rectifying tower to be a third preset value and the temperature in the rectifying tower to be a fourth preset value; the third preset value is 50-60 ℃; the fourth preset value is 115-125 ℃;
and collecting a product at the bottom of the rectifying tower, and sampling and analyzing the NMP purity, the free ammonia content and the water content of the product, wherein the free ammonia content of the product is less than or equal to 10ppm.
2. The method for removing free ammonia from NMP according to claim 1, characterized in that said predetermined liquid level is 90% of said full liquid level.
3. The method for removing free ammonia from NMP according to claim 1, characterized in that said first predetermined value is 6% and said third predetermined value is 52-55 ℃ when the free ammonia content of said NMP waste liquid is 100 ppm.
4. The method for removing free ammonia from NMP according to claim 1, characterized in that said first predetermined value is 10% and said third predetermined value is 50-60 ℃ when the free ammonia content of said NMP waste liquid is 500 ppm.
5. The method for removing free ammonia from NMP according to claim 1, characterized in that said step of collecting the product at the bottom of said rectifying column comprises:
collecting a product at the bottom of the rectifying tower by using a product collecting tank, and performing sampling analysis when the liquid level in the product collecting tank reaches a first set liquid level;
after the product in the product collecting tank is qualified, inputting the product into a finished product storage tank;
when the liquid level in the finished product storage tank reaches a second set liquid level, the liquid level is used as a batch for sampling analysis, and the liquid level is qualified for production and use.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410021251.1A CN117510390B (en) | 2024-01-08 | 2024-01-08 | Method and system for removing free ammonia in NMP |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410021251.1A CN117510390B (en) | 2024-01-08 | 2024-01-08 | Method and system for removing free ammonia in NMP |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117510390A CN117510390A (en) | 2024-02-06 |
| CN117510390B true CN117510390B (en) | 2024-03-29 |
Family
ID=89763102
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410021251.1A Active CN117510390B (en) | 2024-01-08 | 2024-01-08 | Method and system for removing free ammonia in NMP |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117510390B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102001986A (en) * | 2010-12-23 | 2011-04-06 | 上海化学试剂研究所 | Method for improving quality of industrial N-methylpyrrolidone |
| CN206814666U (en) * | 2017-04-27 | 2017-12-29 | 迈奇化学股份有限公司 | A kind of refining system of N methyl pyrrolidones product |
| CN108794371A (en) * | 2017-04-27 | 2018-11-13 | 迈奇化学股份有限公司 | A kind of process for purification of N-Methyl pyrrolidone product |
| CN116239514A (en) * | 2023-03-20 | 2023-06-09 | 重庆中润新材料股份有限公司 | Method for reducing free amine in NMP |
| CN116370988A (en) * | 2023-05-11 | 2023-07-04 | 深圳市百瑞空气处理设备有限公司 | Free ammonia removal method for NMP (N-methyl pyrrolidone) rectification system |
| CN116947728A (en) * | 2023-07-11 | 2023-10-27 | 福建中禾新材料有限公司 | Novel method and device for energy-saving recovery of NMP (N-methyl pyrrolidone) by single tower |
| CN117138380A (en) * | 2023-10-18 | 2023-12-01 | 湖北源源新材料科技有限公司 | NMP rectifying system |
-
2024
- 2024-01-08 CN CN202410021251.1A patent/CN117510390B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102001986A (en) * | 2010-12-23 | 2011-04-06 | 上海化学试剂研究所 | Method for improving quality of industrial N-methylpyrrolidone |
| CN206814666U (en) * | 2017-04-27 | 2017-12-29 | 迈奇化学股份有限公司 | A kind of refining system of N methyl pyrrolidones product |
| CN108794371A (en) * | 2017-04-27 | 2018-11-13 | 迈奇化学股份有限公司 | A kind of process for purification of N-Methyl pyrrolidone product |
| CN116239514A (en) * | 2023-03-20 | 2023-06-09 | 重庆中润新材料股份有限公司 | Method for reducing free amine in NMP |
| CN116370988A (en) * | 2023-05-11 | 2023-07-04 | 深圳市百瑞空气处理设备有限公司 | Free ammonia removal method for NMP (N-methyl pyrrolidone) rectification system |
| CN116947728A (en) * | 2023-07-11 | 2023-10-27 | 福建中禾新材料有限公司 | Novel method and device for energy-saving recovery of NMP (N-methyl pyrrolidone) by single tower |
| CN117138380A (en) * | 2023-10-18 | 2023-12-01 | 湖北源源新材料科技有限公司 | NMP rectifying system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117510390A (en) | 2024-02-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN210085330U (en) | Separation device for recovering dimethyl sulfoxide | |
| CN105418368A (en) | Technology and device for producing high-purity ethyl alcohol | |
| CN111704109A (en) | Method and system for preparing electronic-grade hydrofluoric acid by continuous method | |
| CN104925759B (en) | Continuous production method of sulfuric acid with ultrahigh purity | |
| CN105329961A (en) | Waste water treatment system for recycling DMF at low cost | |
| CN106957124A (en) | A kind of tertiary cathode material produces the processing method and processing system of waste water | |
| CN110780654B (en) | Production process control system for plant extraction | |
| CN108313983A (en) | The hydrofluoric acid purifying prepared for high purity lithium fluoride and preparation method | |
| CN117510390B (en) | Method and system for removing free ammonia in NMP | |
| CN210448119U (en) | Continuous enrichment facility of quaternary ammonium alkaline aqueous solution | |
| CN103601152A (en) | Method and apparatus for intermittent production of hyperpure 16O water during vacuum cascade rectification of heavy-oxygen water | |
| CN115196654A (en) | Liquid lithium hexafluorophosphate synthesis device and application thereof | |
| CN108862348A (en) | A kind of recoverying and utilizing method of electrode foil corrosion Waste Sulfuric Acid | |
| CN112079337A (en) | Production method of electronic grade high-purity ultra-clean sulfuric acid | |
| CN102502701B (en) | Production process and preparation method of ultrapure ammonia | |
| CN103086329A (en) | Method for producing electronic-grade sulfuric acid through falling film crystallization | |
| CN103130624A (en) | Method of gradually evaporating/condensing to concentrate formaldehyde | |
| CN216777931U (en) | Vacuum purification device of methyl pyrrolidone waste liquid | |
| CN103112872A (en) | Preparation method of ultrapure fluorine-ammonium etching solution for micro-electronics | |
| CN113171629B (en) | Trichlorosilane differential pressure coupling rectification process and dynamic control scheme | |
| CN210419808U (en) | Fusel recovery system in BDO device waste liquid | |
| Kang et al. | Thermodynamic analysis of a mechanical vapor recompression evaporation system coupled with crystalization for salt separation | |
| CN103183610B (en) | A kind of method from low-purity methyl acetate high-purity methyl acetate | |
| CN216571605U (en) | Device for controlling ethyl methyl carbonate impurities | |
| CN205347271U (en) | Produce device of high straight alcohol |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |