WO2018207431A1 - Nmp aqueous solution purification system and purification method - Google Patents

Nmp aqueous solution purification system and purification method Download PDF

Info

Publication number
WO2018207431A1
WO2018207431A1 PCT/JP2018/006954 JP2018006954W WO2018207431A1 WO 2018207431 A1 WO2018207431 A1 WO 2018207431A1 JP 2018006954 W JP2018006954 W JP 2018006954W WO 2018207431 A1 WO2018207431 A1 WO 2018207431A1
Authority
WO
WIPO (PCT)
Prior art keywords
nmp
aqueous solution
pervaporation membrane
purification system
membrane
Prior art date
Application number
PCT/JP2018/006954
Other languages
French (fr)
Japanese (ja)
Inventor
亮輔 寺師
響介 山田
聡 日比
Original Assignee
オルガノ株式会社
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by オルガノ株式会社 filed Critical オルガノ株式会社
Priority to JP2019516899A priority Critical patent/JP6783384B2/en
Publication of WO2018207431A1 publication Critical patent/WO2018207431A1/en

Links

Images

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
    • B01D19/00—Degasification of liquids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/14—Ultrafiltration; Microfiltration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/36—Pervaporation; Membrane distillation; Liquid permeation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/58—Multistep processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/02—Inorganic material
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B39/00—Compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites; Their preparation; After-treatment, e.g. ion-exchange or dealumination
    • C01B39/02—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof; Direct preparation thereof; Preparation thereof starting from a reaction mixture containing a crystalline zeolite of another type, or from preformed reactants; After-treatment thereof
    • C01B39/14—Type A
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B39/00—Compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites; Their preparation; After-treatment, e.g. ion-exchange or dealumination
    • C01B39/02—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof; Direct preparation thereof; Preparation thereof starting from a reaction mixture containing a crystalline zeolite of another type, or from preformed reactants; After-treatment thereof
    • C01B39/20—Faujasite type, e.g. type X or Y
    • C01B39/24—Type Y
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B39/00—Compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites; Their preparation; After-treatment, e.g. ion-exchange or dealumination
    • C01B39/02—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof; Direct preparation thereof; Preparation thereof starting from a reaction mixture containing a crystalline zeolite of another type, or from preformed reactants; After-treatment thereof
    • C01B39/26—Mordenite type
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B39/00—Compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites; Their preparation; After-treatment, e.g. ion-exchange or dealumination
    • C01B39/02—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof; Direct preparation thereof; Preparation thereof starting from a reaction mixture containing a crystalline zeolite of another type, or from preformed reactants; After-treatment thereof
    • C01B39/30—Erionite or offretite type, e.g. zeolite T

Definitions

  • the present invention relates to a purification system and a purification method for an NMP aqueous solution.
  • NMP N-methyl-2-pyrrolidone
  • NMP aqueous solution water
  • PV method pervaporation method
  • a driving force for moving the NMP aqueous solution from the inlet side to the permeate side is obtained by supplying the NMP aqueous solution to the inlet side of the pervaporation membrane and reducing the pressure on the permeate side.
  • water due to the difference in permeation speed between NMP and water, water mainly moves to the permeate side, and separation of NMP and water is performed (Japanese Patent Laid-Open Nos. 2013-018747, 2015-071139, and 2016). -030232).
  • a purification system for an NMP aqueous solution provided with the above-described osmosis vaporization membrane device usually includes a subsystem for removing fine particles and ion components in advance from the NMP aqueous solution supplied to the osmosis vaporization membrane device.
  • the NMP aqueous solution purification system may include a subsystem for removing ionic components, fine particles, and chromaticity components eluted from the pervaporation membrane device after the permeation vaporization membrane device.
  • various containers for temporarily storing an NMP aqueous solution or a concentrated NMP concentrate before being processed are used.
  • An NMP aqueous solution or NMP concentrate is stored in the lower part of the container, and the upper part of the container is a gas phase part made of air in order to absorb fluctuations in the stored amount of the NMP aqueous solution or NMP concentrate.
  • an NMP peroxide is generated by oxidizing an NMP aqueous solution or an NMP concentrate in a container having such a gas phase portion at the top.
  • NMP peroxide is generated, the purity of NMP is lowered. Further, accumulation of NMP peroxide may lead to explosion.
  • the present invention relates to an NMP that can suppress the generation of NMP peroxide in a container in which an NMP aqueous solution or an NMP concentrated solution is stored and an interface between the NMP aqueous solution or the NMP concentrated solution and the gas phase is formed.
  • An object is to provide an aqueous solution purification system.
  • the purification system of the NMP aqueous solution containing NMP and water includes an osmotic vaporization membrane device that removes water from the NMP aqueous solution to produce an NMP concentrate, and an upstream or downstream of the permeable vaporization membrane device. Or it has the container in which NMP concentrate is stored, and the inert gas supply means which fills the gaseous-phase part of a container with an inert gas.
  • the gas phase portion of the container is formed of the inert gas by the inert gas supply means, the generation of NMP peroxide can be suppressed.
  • FIG. 1 shows a schematic configuration diagram of an NMP aqueous solution purification system 1 according to an embodiment of the present invention.
  • CW means cooling water
  • BR means brine
  • ST means high temperature steam.
  • NMP is one of the organic solvents having high solubility in water.
  • NMP is widely used as a slurry dispersion medium when, for example, a slurry in which particles such as an electrode active material are dispersed on an electrode current collector and dried to form an electrode in a manufacturing process of a lithium ion secondary battery. It is used.
  • NMP is recovered when the slurry is dried, and the recovered NMP can be reused after purification.
  • NMP is recovered as a mixed solution (NMP aqueous solution) in which NMP and water are mixed using, for example, a water scrubber.
  • the NMP concentration in the recovered NMP aqueous solution is about 70 to 99% by weight.
  • the NMP aqueous solution purification system 1 removes most of the water from the NMP aqueous solution from which the fine particles and ionic components have been removed in advance by the first subsystem 100 and the pervaporation membrane device from which the fine particles and ionic components have been removed. It has the 2nd subsystem 200 which produces
  • the configuration of each subsystem will be described.
  • the first subsystem 100 includes a receiving tank 101 that receives the NMP aqueous solution to be processed collected as described above.
  • the NMP aqueous solution is supplied to the receiving tank 101 by a first NMP aqueous solution supply line L101 connected to an NMP recovery means (not shown) such as a water scrubber.
  • the receiving tank 101 is connected to a first microfiltration membrane device 102 that removes fine particles contained in the NMP aqueous solution via a second NMP aqueous solution supply line L102.
  • a pump 107 that pumps the NMP aqueous solution is provided on the second NMP aqueous solution supply line L102.
  • the first microfiltration membrane device 102 is provided upstream of the membrane degassing device 103 (described later), but downstream of the membrane degassing device 103, that is, between the membrane degassing device 103 and the ion exchange device 104 (described later). It may be provided between them, or may be provided both upstream of the membrane deaerator 103 and between the membrane deaerator 103 and the ion exchange device 104.
  • the first microfiltration membrane device 102 is connected to a membrane deaeration device 103 that removes dissolved oxygen in the NMP aqueous solution via a third NMP aqueous solution supply line L103.
  • the NMP aqueous solution is heated to about 120 ° C. before being introduced into the pervaporation membrane apparatus 201.
  • NMP may be combined with dissolved oxygen in the NMP aqueous solution and oxidized.
  • a dissolved oxygen meter (not shown) is provided at the inlet line L103 and the outlet line L104 of the membrane deaerator 103.
  • the inlet line L103 of the membrane degassing apparatus 103 is provided with a moisture meter and a specific resistance meter (both not shown).
  • the deaeration membrane of the membrane deaerator 103 can be formed from polyolefin, polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polyurethane, epoxy resin, or the like. Since NMP has the property of dissolving some organic materials, the degassing membrane is preferably formed of polyolefin, PTFE or PFA. The degassing membrane is preferably non-porous.
  • the dissolved oxygen in the NMP aqueous solution flowing inside the hollow fiber-shaped degassing membrane moves to the outside of the degassing membrane that has been made negative pressure by the vacuum pump 109, whereby degassing, that is, removal of dissolved oxygen is performed.
  • the oxygen partial pressure may be lowered by sweeping an inert gas such as nitrogen gas outside the degassing membrane (gas permeation side), or the vacuum method and the sweep method may be used in combination.
  • the membrane deaerator 103 is connected to an ion exchange device 104 that removes ion components of the NMP aqueous solution via a fourth NMP aqueous solution supply line L104.
  • the ion exchange device 104 is filled with an anion exchange resin or a cation exchange resin in a single bed, or an anion exchange resin and a cation exchange resin in a mixed bed or a multilayer bed.
  • the type of ion exchange resin may be either gel type or MR type.
  • the heater 108 may heat the NMP aqueous solution so that the NMP aqueous solution is supplied to the ion exchange device 104 at a temperature suitable for ion exchange.
  • the ion exchange device 104 is connected to the second microfiltration membrane device 105 via the fifth NMP aqueous solution supply line L105.
  • the second microfiltration membrane device 105 captures the resin that may flow out of the ion exchange device 104 and prevents the resin from flowing downstream.
  • the second microfiltration membrane device 105 is connected to the stock solution tank 106 via a sixth NMP aqueous solution supply line L106.
  • the stock solution tank 106 receives the NMP aqueous solution processed by the membrane degassing device 103 and the ion exchange device 104, and supplies the received NMP aqueous solution to the pervaporation membrane device 201.
  • the NMP aqueous solution stored in the stock solution tank 106 and supplied to the pervaporation membrane device 201 may be referred to as an NMP stock solution.
  • the resistivity meter (not shown) is provided in the inlet line L104 and the outlet line L105 of the ion exchange device 104.
  • the specific resistance of the NMP aqueous solution processed by the ion exchange device 104 is smaller than a predetermined value, that is, when the ion component is not sufficiently removed, the NMP aqueous solution can be circulated along a loop passing through the ion exchange device 104.
  • a return line L107 branched from the fifth NMP aqueous solution supply line L105 and connected to the receiving tank 101 is provided. Normally, the valve V101 of the fifth NMP aqueous solution supply line L105 is opened and the valve V102 of the return line L107 is closed.
  • the fifth NMP aqueous solution supply line The valve V101 of L105 is closed and the valve V102 of the return line L107 is opened.
  • a circulation loop is formed that passes through the receiving tank 101, the first microfiltration membrane device 102, the membrane deaeration device 103, and the ion exchange device 104.
  • the dissolved oxygen in the NMP aqueous solution treated by the membrane degassing device 103 is larger than a predetermined value, that is, when the dissolved oxygen is not sufficiently removed, the NMP along the loop passing through the ion exchange device 104 described above.
  • the aqueous solution can be circulated. Thereby, the dissolved oxygen contained in the NMP aqueous solution is also sufficiently removed.
  • the NMP stock solution from which fine particles and ionic components have been removed and stored in the stock solution tank 106 is then supplied to the second subsystem 200 to generate an NMP concentrated solution from which most of the water has been removed.
  • the stock solution tank 106 is connected to the pervaporation membrane device 201 via a seventh NMP aqueous solution supply line L201.
  • the seventh NMP aqueous solution supply line L201 is provided with a pump 224 and a valve V201.
  • the seventh NMP aqueous solution supply line L201 is provided with a first heater 205 using external steam and a waste heat recovery heat exchanger 206 located upstream (primary side) of the first heater 205.
  • the NMP aqueous solution is heated to about 120 ° C.
  • the waste heat recovery heat exchanger 206 performs heat exchange between the NMP aqueous solution flowing through the seventh NMP aqueous solution supply line L201 and the NMP concentrated solution flowing through the NMP concentrated liquid discharge line L204.
  • the first heater 205 heats the NMP aqueous solution with steam supplied from an external steam source (not shown).
  • the steam supply line of the first heater 205 is provided with a valve V202 for adjusting the steam supply amount.
  • a temperature alarm indicator 223 is provided downstream of the first heater 205.
  • the opening degree of the valve V202 is adjusted based on the temperature detected by the temperature alarm indicator 223, and the temperature of the NMP aqueous solution is controlled to about 120 ° C.
  • a flow rate alarm indicator 225 is provided upstream of the waste heat recovery heat exchanger 206 in the seventh NMP aqueous solution supply line L201.
  • the opening degree of the valve V201 is adjusted based on the flow rate detected by the flow rate alarm indicator 225, and the flow rate of the NMP aqueous solution is controlled within a predetermined range.
  • the pervaporation membrane device 201 has a plurality of pervaporation membrane modules connected in series.
  • three pervaporation membrane modules that is, a first pervaporation membrane module 202, a second pervaporation membrane module 203, and a third pervaporation membrane module 204 are connected in series from upstream to downstream.
  • the first pervaporation membrane module 202 is connected to the second pervaporation membrane module 203 via the first connection line L202.
  • the second pervaporation membrane module 203 is connected to the third pervaporation membrane module 204 via the second connection line L203.
  • the first to third pervaporation membrane devices 202, 203, 204 are separated by upstream separation chambers 202 a, 203 a, 204 a and downstream permeation chambers 202 b, 203 b, by separation membranes (permeation vaporization membranes) 202 c, 203 c, 204 c. 204b. Since the separation membranes 202c, 203c, and 204c have an affinity for water, the water is allowed to permeate the separation membranes 202c, 203c, and 204c at a higher transmission rate than NMP.
  • the NMP aqueous solution sequentially flows through the first to third pervaporation membrane modules 202, 203, and 204, and moisture in the NMP aqueous solution is gradually removed.
  • the first connection line L202 and the second connection line L203 are provided with the second heater 207 and the third heater 208, respectively.
  • the second and third heaters 207 and 208 are heat exchangers, and heat the NMP aqueous solution to about 120 ° C. by steam supplied from an external steam source.
  • the steam supply lines of the second and third heaters 207 and 208 are provided with valves V203 and V204 for adjusting the steam supply amount, respectively.
  • the NMP concentrated water discharged from the third pervaporation membrane module 204 is supplied to the relay tank 301 of the third subsystem 300 through the NMP concentrated liquid discharge line L204.
  • the NMP concentrated liquid flowing through the NMP concentrated liquid discharge line L204 is subjected to heat exchange with the NMP aqueous solution flowing through the seventh NMP aqueous solution supply line L201 by the waste heat recovery heat exchanger 206. Preheat the aqueous solution.
  • An NMP concentrate return line L215 branched from the NMP concentrate discharge line L204 and connected to the stock solution tank 106 is provided. Normally, the valve V205 of the NMP concentrate discharge line L204 is opened, the valve V206 of the return line L215 is closed, and the NMP concentrate is supplied to the relay tank 301. On the other hand, when the NMP concentrate cannot be supplied to the relay tank 301, the valve V205 is closed, the valve V206 is opened, and the NMP concentrate is returned to the stock tank 106.
  • the cooler 226 provided in the return line L215 is cooled by cooling water so that the temperature of the NMP concentrated solution becomes approximately the same as the temperature of the NMP aqueous solution (stock solution). Cooling.
  • the permeation chambers 202b, 203b, 204b of the first to third pervaporation membrane modules 202, 203, 204 are respectively connected to the first to third permeate tanks by the first to third permeate discharge lines L206, L209, L212. 214, 215, 216.
  • Vapor phase water and a small amount of NMP are condensed by cooling water or brine and collected at the bottom of the first to third permeate tanks 214, 215, 216.
  • the cooling water or brine flows through a cooling jacket (not shown) covering the periphery of the first to third permeate tanks 214, 215, and 216 to keep the vapor phase water and NMP cold, and further to the cooling line.
  • Gas phase water is supplied to the first to third heat exchangers 211, 212, and 213 provided in the first to third permeate discharge lines L206, L209, and L212 through L207, L210, and L213. And condensing NMP.
  • the temperature of the brine is preferably about 0 to -20 ° C.
  • First to third condensed water discharge lines L208, L211, and L214 are connected to the bottoms of the first to third permeate tanks 214, 215, and 216, respectively, and the first to third condensed water discharge lines are connected.
  • L208, L211, and L214 are provided with first to third discharge pumps 220, 221, and 222, respectively.
  • the condensed water and a small amount of NMP are discharged from the first to third permeate tanks 214, 215, and 216 by the first to third discharge pumps 220, 221, and 222, respectively. Further, first to third vacuum pumps 217, 218, and 219 for applying a negative pressure to the permeation chambers 201b, 202b, and 203b are provided above the first to third permeate tanks 214, 215, and 216, respectively. Yes.
  • the most upstream pervaporation membrane module that is, the first pervaporation membrane module 202 has a permeation vaporization membrane 202c made of CHA type, T type, Y type or MOR type zeolite.
  • the permeate vaporization membrane modules other than the most upstream pervaporation membrane module that is, the second and third pervaporation membrane modules 203 and 204 have permeate vaporization membranes 203c and 204c made of A-type zeolite.
  • A-type zeolite is relatively inexpensive and has high dehydration performance, leaks and performance degradation are likely to occur when processing an NMP aqueous solution having a high water concentration.
  • the pervaporation membrane 202c of the first pervaporation membrane module 202 for treating the NMP aqueous solution containing 10 to 20% by weight of water uses CHA type, T type, Y type or MOR type zeolite, and contains water.
  • A-type zeolite is used for the pervaporation membranes 203c and 204c of the second and third pervaporation membrane modules 203 and 204 for treating a small amount of NMP aqueous solution.
  • the plurality of pervaporation membranes constituting the first pervaporation membrane module 202 are CHA type, T type, Y type, or MOR type zeolite, and some membranes are A type zeolite. It may consist of
  • the third permeate discharge line L212 is provided with a cooler 209 and a mechanical booster pump 210.
  • the cooler 209 precools the permeate discharged from the third pervaporation membrane module 204.
  • the mechanical booster pump 210 and the cooler 209 are provided to apply a large negative pressure to the permeation chamber 204b of the third pervaporation membrane module 204. Since the water content of the NMP aqueous solution supplied to the third pervaporation membrane module 204 is very small, water can be removed by applying a sufficient negative pressure with the mechanical booster pump 210 in addition to the third vacuum pump 219. It can be efficiently separated from the NMP aqueous solution.
  • the cooler 209 and the mechanical booster pump 210 can be omitted. Further, a pod (not shown) for storing the condensed water condensed by the cooler 209 can be provided between the cooler 209 and the mechanical booster pump 210.
  • the permeated liquid of the second and third pervaporation membrane modules 203 and 204 is collected on the upstream side of the pervaporation membrane device 201.
  • the second and third permeate discharge lines L211 and L214 are connected to the permeate recovery line L205, and the permeate recovery line L205 is connected to the stock solution tank.
  • the permeate discharged from the second and third permeate discharge lines L211 and L214 has a higher NMP content than the permeate discharged from the first permeate discharge line L208. , NMP recovery rate can be increased.
  • the permeate vaporization membrane module from which the permeate is collected is not limited to the second and third pervaporation membrane modules 203 and 204, and at least the permeate vaporization membrane module (third pervaporation membrane module 204) at the most downstream side. May be recovered upstream of the pervaporation membrane device 201.
  • the permeate may be collected in the receiving tank 101 or may be selectively collected in the stock liquid tank 106 and the receiving tank 101 by providing a branch line (not shown) in the permeate collecting line L205.
  • the NMP concentrate contains a small amount of fine particles and ionic components of the pervaporation membranes 202c, 203c, and 204c eluted from the chromaticity component and the pervaporation membrane module.
  • NMP purified solution is produced by distillation in the subsystem 300.
  • the third subsystem 300 described below uses a simple distillation method, the distillation method is not limited as long as the NMP concentrated solution can be distilled. For example, a precision distillation method can also be used. However, the simple distillation method is preferred because it consumes less energy, the apparatus size is small, and the operation is simple.
  • the reduced pressure simple distillation method used in this embodiment is particularly desirable from the viewpoint of preventing thermal deterioration.
  • the NMP concentrate is temporarily stored in the relay tank 301.
  • the third subsystem 300 is an independent subsystem from the second subsystem 200. For example, the operation of temporarily stopping the operation of the third subsystem 300 during the operation of the second subsystem 200 is performed. Sometimes done. For this reason, by providing the relay tank 301, it becomes possible to operate the second subsystem 200 and the third subsystem 300 more flexibly while maintaining mutual independence.
  • the relay tank 301 is connected to the regenerator 302 via the first NMP concentrate supply line L301.
  • the first NMP concentrate supply line L301 is provided with a pump 306 and a valve V301.
  • the regenerator 302 is a heat exchanger, and performs heat exchange with an NMP concentrated liquid (hereinafter referred to as NMP purified gas) evaporated in an evaporator 303 described later. Thereby, the thermal load of the evaporator 303 can be reduced.
  • the regenerator 302 is connected to the evaporator 303 via the second NMP concentrate supply line L302.
  • the evaporator 303 heats and evaporates the NMP concentrated liquid with steam supplied from an external steam source (not shown).
  • the vapor supply line of the evaporator 303 is provided with a valve V302 for adjusting the vapor supply amount.
  • a high temperature liquid phase NMP concentrate stays at the bottom of the evaporator 303, and a gas phase NMP purified gas from which fine particles have been removed is formed at the top.
  • the chromaticity component contained in the liquid phase NMP concentrate is also difficult to evaporate, and is therefore accumulated at the bottom of the evaporator 303.
  • the evaporator 303 in the present embodiment will be described below by taking a liquid film flow-down type evaporator as an example, but an evaporator other than the liquid film flow-down type, for example, an evaporator such as a flash type or a calandria type can be used. It may be used.
  • a circulation line L303 is connected to the bottom and top of the evaporator 303, and a cycle of taking out the liquid phase NMP concentrate and returning it to the evaporator 303 and heating it again under the flow of the liquid film is repeated.
  • an NMP concentrated liquid take-out line L306 that joins with the circulation line L303 is provided.
  • the NMP concentrate staying at the bottom of the vapor takeout can 304 is also returned to the evaporator 303 through the NMP concentrate takeout line L306 and the circulation line L303 and heated again.
  • the circulation line L303 is provided with a circulation pump 307 and a valve V303. From the circulation line L303, an NMP concentrate discharge line L309 provided with a valve V304 branches.
  • the NMP purified gas in the evaporator 303 is taken out from the vapor phase portion of the evaporator 303 and taken out to the vapor takeout can 304 by the first NMP purified gas takeout line L304.
  • the steam take-out can 304 is connected to the regenerator 302 via the second NMP purified gas take-out line L305.
  • the heat of the NMP purified gas is heat-exchanged with the liquid phase NMP concentrate in the regenerator 302.
  • the NMP purified gas exiting the regenerator 302 is further introduced into the condenser 305 by the third NMP purified gas take-out line L307 and condensed by the cooling water to become NMP purified water.
  • NMP purified water take-out pipe L308 is connected to the outlet of the capacitor 305. NMP purified water is discharged out of the NMP aqueous solution purification system 1 by a pump 308 provided in the NMP purified water take-out pipe L308.
  • the NMP aqueous solution purification system 1 of this embodiment further includes an inert gas supply means for filling the gas phase portion of the container with an inert gas.
  • an inert gas supply means for filling the gas phase portion of the container with an inert gas.
  • various containers for storing the NMP aqueous solution, the NMP concentrated solution, or the NMP purified solution are provided upstream and downstream of the pervaporation membrane device 201. In some of these containers, an interface between an NMP aqueous solution, an NMP concentrated solution or an NMP purified solution, and a gas phase part is formed. Examples of containers that satisfy this condition include the following.
  • NMP aqueous solution receiving tank 101 Stock solution tank 106 (3) Relay tank 301 (4) Regenerator 302 (5) Evaporator 303 (6) Steam take-out can 304 (7) Capacitor 305
  • the containers mean the containers 101, 106, 301 to 305) with NMP, the NMP is the gas in the gas phase. It was found that an NMP peroxide (NMP-O—O—H; 5-hydroperoxo-1-methyl-2-pyrrolidone) was produced in combination. The accumulation of NMP peroxide may cause an explosion.
  • these containers are provided with inert gas supply means.
  • Nitrogen gas is preferable as the inert gas, and argon gas can also be used.
  • the inert gas supply means is installed on an inert gas supply mother pipe L401 described below, an inert gas supply line that branches from the mother pipe L401 and supplies an inert gas to each vessel, and each inert gas supply line. Gas seal unit.
  • an inert gas supply mother pipe L401 is connected to an inert gas supply source (not shown), and the inert gas supply mother pipe L401, the receiving tank 101, the stock solution tank 106, and the relay tank 301 are each inert gas. They are connected by supply lines L402, 403, and 404. Inert gas supply lines L402, 403, and 404 are connected to the top of the container. Inert gas supply lines L402, 403, and 404 are provided with gas seal units U402, U403, and U404, respectively.
  • a vacuum pump 309 connected to the capacitor 305 is provided, and a sweep inert gas supply line L405 is connected to a pipe between the capacitor 305 and the vacuum pump 309.
  • the inert gas is supplied to the condenser 305 from the inert gas supply line L405, and the inert gas is also supplied to the regenerator 302, the evaporator 303, and the steam take-out can 304 through the lines L307, L302, L304, and L305. .
  • the regenerator 302, the evaporator 303, and the steam take-out can 304 can be provided with a similar vacuum pump and an inert gas supply line for sweeping.
  • the gas seal units U402, U403, and U404 will be described as an example, but the same applies to other gas seal units.
  • the gas seal units U402, U403, and U404 are automatically opened when the pressure in the downstream container decreases, and are filled with an inert gas. Therefore, when the amount of the NMP aqueous solution, the NMP concentrated liquid, and the NMP purified liquid in the container decreases, the pressure of the container decreases, and the inert gas is replenished to the container through the gas seal units U402, U403, and U404.
  • the inert gas is filled into the container when the NMP aqueous solution purification system 1 is first operated. At this time, since the inside of the container is filled with air, the inert gas is fed into the container through the gas seal units U402, U403, U404, and the air inside the container is forcibly replaced with the inert gas.
  • Example 2 The container was filled with an NMP aqueous solution, and the change over time in the peroxide concentration in the NMP aqueous solution was measured using the upper part as a gas phase.
  • the gas phase was nitrogen gas (> 99.9% by weight or more), and in the comparative example, the gas phase was air.
  • the container was left for 30 days in a state filled with an NMP aqueous solution and nitrogen gas or air, and the concentration of NMP peroxide was measured by an iodometric titration method. The results are shown in Table 1. Thus, it was confirmed that the concentration of NMP peroxide in the NMP aqueous solution can be suppressed to almost zero by substituting the gas phase with nitrogen.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Inorganic Chemistry (AREA)
  • Water Supply & Treatment (AREA)
  • Materials Engineering (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)
  • Degasification And Air Bubble Elimination (AREA)

Abstract

In this NMP aqueous solution purification system 1, the generation of peroxides of NMP is suppressed. This NMP aqueous solution purification system 1 is provided with: a pervaporation membrane device 201 for removing water from an NMP aqueous solution to prepare an NMP concentrated solution; containers 101, 103, 106, 301 which is provided on the upstream side or the downstream side of the pervaporation membrane device 201 and stores the NMP aqueous solution or the NMP concentrated solution; and inert gas supply means L401-405, U402-U405 for filling gas phase parts of the containers 101, 103, 106, 301 with inert gas.

Description

ＮＭＰ水溶液の精製システム及び精製方法NMP aqueous solution purification system and purification method
　本出願は、２０１７年５月１０日出願の日本出願である特願２０１７－９３９３５に基づき、かつ同出願に基づく優先権を主張する。この出願は、その全体が参照によって本出願に取り込まれる。 This application is based on Japanese Patent Application No. 2017-93935 filed on May 10, 2017, and claims priority based on this application. This application is incorporated herein by reference in its entirety.
　本発明はＮＭＰ水溶液の精製システムと精製方法に関する。 The present invention relates to a purification system and a purification method for an NMP aqueous solution.
　従来から、Ｎ－メチル－２－ピロリドン（以下、ＮＭＰという）と水との混合液（以下、ＮＭＰ水溶液という）から、浸透気化法（ＰＶ法）を用いてＮＭＰを分離する方法が知られている。ＰＶ法はＮＭＰ水溶液を減圧して蒸留する方法（減圧蒸留法）と比べ、省エネルギー性能に優れている。ＰＶ法では水と親和性のある分離膜（浸透気化膜）を備えた浸透気化膜装置が用いられる。浸透気化膜の入口側にＮＭＰ水溶液を供給し透過側を減圧することで、ＮＭＰ水溶液を入口側から透過側へ移動させる駆動力が得られる。この際、ＮＭＰと水の透過速度差により、主に水が透過側に移動し、ＮＭＰと水の分離が行われる（特開２０１３－０１８７４７号公報、特開２０１５－０７１１３９号公報、特開２０１６－０３０２３２号公報）。 Conventionally, a method for separating NMP from a mixed solution of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) and water (hereinafter referred to as NMP aqueous solution) by using a pervaporation method (PV method) is known. Yes. The PV method is superior in energy saving performance as compared with a method (vacuum distillation method) in which an NMP aqueous solution is distilled under reduced pressure. In the PV method, an osmosis vapor membrane apparatus having a separation membrane (permeation vaporization membrane) having an affinity for water is used. A driving force for moving the NMP aqueous solution from the inlet side to the permeate side is obtained by supplying the NMP aqueous solution to the inlet side of the pervaporation membrane and reducing the pressure on the permeate side. At this time, due to the difference in permeation speed between NMP and water, water mainly moves to the permeate side, and separation of NMP and water is performed (Japanese Patent Laid-Open Nos. 2013-018747, 2015-071139, and 2016). -030232).
　上述の浸透気化膜装置を備えるＮＭＰ水溶液の精製システムは通常、浸透気化膜装置に供給されるＮＭＰ水溶液から微粒子やイオン成分を予め除去するためのサブシステムを備える。ＮＭＰ水溶液の精製システムは、浸透気化膜装置の後段に、浸透気化膜装置から溶出するイオン成分、微粒子および色度成分を除去するためのサブシステムを備えることもある。これらのサブシステムでは、処理される前のＮＭＰ水溶液や濃縮されたＮＭＰ濃縮液を一時的に貯留する様々な容器が用いられる。容器の下部にはＮＭＰ水溶液またはＮＭＰ濃縮液が貯留され、容器の上部はＮＭＰ水溶液またはＮＭＰ濃縮液の貯留量の変動を吸収するため、空気からなる気相部となっている。 A purification system for an NMP aqueous solution provided with the above-described osmosis vaporization membrane device usually includes a subsystem for removing fine particles and ion components in advance from the NMP aqueous solution supplied to the osmosis vaporization membrane device. The NMP aqueous solution purification system may include a subsystem for removing ionic components, fine particles, and chromaticity components eluted from the pervaporation membrane device after the permeation vaporization membrane device. In these subsystems, various containers for temporarily storing an NMP aqueous solution or a concentrated NMP concentrate before being processed are used. An NMP aqueous solution or NMP concentrate is stored in the lower part of the container, and the upper part of the container is a gas phase part made of air in order to absorb fluctuations in the stored amount of the NMP aqueous solution or NMP concentrate.
　本願発明者は、このような上部が気相部となっている容器において、ＮＭＰ水溶液またはＮＭＰ濃縮液が酸化することで、ＮＭＰの過酸化物が生成されることを見出した。ＮＭＰの過酸化物が生成すると、ＮＭＰの純度が低下してしまう。また、ＮＭＰの過酸化物が蓄積すると爆発に至る可能性がある。 The inventor of the present application has found that an NMP peroxide is generated by oxidizing an NMP aqueous solution or an NMP concentrate in a container having such a gas phase portion at the top. When NMP peroxide is generated, the purity of NMP is lowered. Further, accumulation of NMP peroxide may lead to explosion.
　本発明は、内部にＮＭＰ水溶液またはＮＭＰ濃縮液が貯留され、ＮＭＰ水溶液またはＮＭＰ濃縮液と気相部との界面が形成される容器において、ＮＭＰの過酸化物の生成を抑制することのできるＮＭＰ水溶液の精製システムを提供することを目的とする。 The present invention relates to an NMP that can suppress the generation of NMP peroxide in a container in which an NMP aqueous solution or an NMP concentrated solution is stored and an interface between the NMP aqueous solution or the NMP concentrated solution and the gas phase is formed. An object is to provide an aqueous solution purification system.
　本発明のＮＭＰと水とを含むＮＭＰ水溶液の精製システムは、ＮＭＰ水溶液から水を除去してＮＭＰ濃縮液を生成する浸透気化膜装置と、浸透気化膜装置の上流または下流に設けられ、ＮＭＰ水溶液またはＮＭＰ濃縮液が貯留される容器と、容器の気相部を不活性ガスで充填する不活性ガス供給手段と、を有する。 The purification system of the NMP aqueous solution containing NMP and water according to the present invention includes an osmotic vaporization membrane device that removes water from the NMP aqueous solution to produce an NMP concentrate, and an upstream or downstream of the permeable vaporization membrane device. Or it has the container in which NMP concentrate is stored, and the inert gas supply means which fills the gaseous-phase part of a container with an inert gas.
　本発明によれば、容器の気相部が不活性ガス供給手段によって不活性ガスで形成されるため、ＮＭＰの過酸化物の生成を抑制することができる。 According to the present invention, since the gas phase portion of the container is formed of the inert gas by the inert gas supply means, the generation of NMP peroxide can be suppressed.
　上述した、およびその他の、本出願の目的、特徴、および利点は、本出願を例示した添付の図面を参照する以下に述べる詳細な説明によって明らかとなろう。 The above and other objects, features, and advantages of the present application will become apparent from the detailed description set forth below with reference to the accompanying drawings, which illustrate the present application.
本発明の一実施形態に係るＮＭＰ水溶液の精製システムの概略構成図である。It is a schematic block diagram of the refinement | purification system of NMP aqueous solution which concerns on one Embodiment of this invention.
　１　ＮＭＰ水溶液の精製システム
　１００　第１のサブシステム
　１０１　受槽
　１０２　第１の精密ろ過膜装置
　１０３　膜脱気装置
　１０４　イオン交換装置
　１０５　第２の精密ろ過膜装置
　１０６　原液槽
　１０７　ポンプ
　１０８　ヒータ
　Ｌ１０１～Ｌ１０６　第１～第６のＮＭＰ水溶液供給ライン
　Ｌ１０７　戻りライン
　Ｖ１０１，１０２　弁
　２００　第２のサブシステム
　２０１　浸透気化膜装置
　２０２～２０４　第１～第３の浸透気化膜モジュール
　２０２ａ，２０３ａ，２０４ａ　濃縮室
　２０２ｂ，２０３ｂ，２０４ｂ　透過室
　２０２ｃ、２０３ｃ、２０４ｃ　分離膜（浸透気化膜）
　２０５　第１のヒータ
　２０６　再生式熱交換器
　２０７　第２のヒータ
　２０８　第３のヒータ
　２０９　冷却器
　２１０　メカニカルブースターポンプ
　２１１，２１２，２１３　第１～第３の熱交換器
　２１４，２１５，２１６　第１～第３の透過液タンク
　２１７，２１８，２１９　第１～第３の真空ポンプ
　２２０，２２１，２２２　第１～第３の排出ポンプ
　２２３　温度警報表示器
　２２４　ポンプ
　２２５　流量警報表示器
　２２６　冷却器
　Ｌ２０１　第７のＮＭＰ水溶液供給ライン
　Ｌ２０２，Ｌ２０３　第１、第２の接続ライン
　Ｌ２０４　ＮＭＰ濃縮液排出ライン
　Ｌ２０５　透過液回収ライン
　Ｌ２０６，Ｌ２０９，Ｌ２１２　第１～第３の透過液排出ライン
　Ｌ２０７，Ｌ２１０、Ｌ２１３　冷却ライン
　Ｌ２０８，Ｌ２１１，Ｌ２１４　第１～第３の凝縮水排出ライン
　Ｌ２１５　ＮＭＰ濃縮液の戻りライン
　Ｖ２０１～Ｖ２０６　弁
　３００　第３のサブシステム
　３０１　中継槽
　３０２　再生器
　３０３　蒸発缶
　３０４　蒸気取り出し缶
　３０５　コンデンサ
　３０６　ポンプ
　３０７　循環ポンプ
　３０８　ポンプ
　Ｌ３０１　第１のＮＭＰ濃縮液供給ライン
　Ｌ３０２　第２のＮＭＰ濃縮液供給ライン
　Ｌ３０３　循環ライン
　Ｌ３０４　第１のＮＭＰ精製ガス取り出しライン
　Ｌ３０５　第２のＮＭＰ精製ガス取り出しライン
　Ｌ３０６　ＮＭＰ濃縮液取り出しライン
　Ｌ３０７　第３のＮＭＰ精製ガス取り出しライン
　Ｌ３０８　ＮＭＰ精製水取り出し配管
　Ｌ３０９　ＮＭＰ濃縮液の排出ライン
　Ｖ３０１～Ｖ３０４　弁
　Ｌ４０１　不活性ガス供給母管
　Ｌ４０２，４０３，４０４　不活性ガス供給ライン
　Ｕ４０２，Ｕ４０３，Ｕ４０４　ガスシールユニット DESCRIPTION OF SYMBOLS 1 NMP aqueous solution purification system 100 1st subsystem 101 Receiving tank 102 1st microfiltration membrane apparatus 103 Membrane deaeration apparatus 104 Ion exchange apparatus 105 2nd microfiltration membrane apparatus 106 Stock solution tank 107 Pump 108 Heater L101-L106 1st 1st to 6th NMP aqueous solution supply line L107 Return line V101, 102 Valve 200 2nd subsystem 201 Permeation vaporization membrane device 202-204 1st to 3rd pervaporation membrane module 202a, 203a, 204a Concentration chamber 202b, 203b 204b Permeation chamber 202c, 203c, 204c Separation membrane (pervaporation membrane)
205 first heater 206 regenerative heat exchanger 207 second heater 208 third heater 209 cooler 210 mechanical booster pump 211, 212, 213 first to third heat exchangers 214, 215, 216 first to Third permeate tanks 217, 218, 219 First to third vacuum pumps 220, 221, 222 First to third discharge pumps 223 Temperature alarm indicator 224 Pump 225 Flow rate alarm indicator 226 Cooler L201 7th NMP aqueous solution supply line L202, L203 First and second connection lines L204 NMP concentrate discharge line L205 Permeate recovery line L206, L209, L212 First to third permeate discharge lines L207, L210, L213 Cooling line L208 , L211, L214 First to third condensed water discharge lines 215 NMP concentrated liquid return line V201 to V206 Valve 300 Third subsystem 301 Relay tank 302 Regenerator 303 Evaporator 304 Steam takeout 305 Capacitor 306 Pump 307 Circulating pump 308 Pump L301 First NMP concentrated liquid supply line L302 First 2 NMP concentrate supply line L303 Circulation line L304 First NMP purified gas take-out line L305 Second NMP purified gas take-out line L306 NMP concentrated liquid take-out line L307 Third NMP purified gas take-out line L308 NMP purified water take-out pipe L309 NMP concentrate discharge line V301 to V304 Valve L401 Inert gas supply mother pipe L402, 403, 404 Inert gas supply line U402, U403, U404 Gas seal unit G
　以下、図面を参照して本発明の一実施形態に係るＮＭＰ水溶液の精製システムと精製方法を説明する。図１は、本発明の一実施形態に係るＮＭＰ水溶液の精製システム１の概略構成図を示している。図中、ＣＷは冷却水を、ＢＲはブラインを、ＳＴは高温蒸気を意味する。 Hereinafter, an NMP aqueous solution purification system and method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration diagram of an NMP aqueous solution purification system 1 according to an embodiment of the present invention. In the figure, CW means cooling water, BR means brine, and ST means high temperature steam.
　ＮＭＰは水に対して高い溶解度を有する有機溶剤の一つである。ＮＭＰは、例えば、リチウムイオン二次電池の製造工程において電極活物質などの粒子を分散させたスラリーを電極集電体上に塗布し乾燥させて電極を形成する際に、スラリーの分散媒として広く用いられている。スラリーを乾燥させる際にＮＭＰが回収され、回収されたＮＭＰは精製した後に再利用することができる。ＮＭＰは、例えば水スクラバーを用いて、ＮＭＰと水とが混合した混合液（ＮＭＰ水溶液）として回収される。回収されたＮＭＰ水溶液におけるＮＭＰ濃度は、７０～９９重量％程度である。 NMP is one of the organic solvents having high solubility in water. NMP is widely used as a slurry dispersion medium when, for example, a slurry in which particles such as an electrode active material are dispersed on an electrode current collector and dried to form an electrode in a manufacturing process of a lithium ion secondary battery. It is used. NMP is recovered when the slurry is dried, and the recovered NMP can be reused after purification. NMP is recovered as a mixed solution (NMP aqueous solution) in which NMP and water are mixed using, for example, a water scrubber. The NMP concentration in the recovered NMP aqueous solution is about 70 to 99% by weight.
　ＮＭＰ水溶液の精製システム１は、ＮＭＰ水溶液から微粒子やイオン成分を予め除去する第１のサブシステム１００と、微粒子やイオン成分が除去されたＮＭＰ水溶液から浸透気化膜装置によって水分のほとんどを除去してＮＭＰ濃縮液を生成する第２のサブシステム２００と、ＮＭＰ濃縮液を蒸留してＮＭＰ精製液を生成する第３のサブシステム３００と、を有している。以下、個々のサブシステムの構成を説明する。 The NMP aqueous solution purification system 1 removes most of the water from the NMP aqueous solution from which the fine particles and ionic components have been removed in advance by the first subsystem 100 and the pervaporation membrane device from which the fine particles and ionic components have been removed. It has the 2nd subsystem 200 which produces | generates NMP concentrate, and the 3rd subsystem 300 which distills NMP concentrate and produces | generates NMP refinement | purification liquid. Hereinafter, the configuration of each subsystem will be described.
　（第１のサブシステム１００）
　第１のサブシステム１００は、上述のようにして回収された処理対象のＮＭＰ水溶液を受け入れる受槽１０１を有している。ＮＭＰ水溶液は、水スクラバーなどのＮＭＰ回収手段（図示せず）と接続された第１のＮＭＰ水溶液供給ラインＬ１０１によって、受槽１０１に供給される。受槽１０１は第２のＮＭＰ水溶液供給ラインＬ１０２を介して、ＮＭＰ水溶液に含まれる微粒子を除去する第１の精密ろ過膜装置１０２と接続されている。第２のＮＭＰ水溶液供給ラインＬ１０２上にはＮＭＰ水溶液を圧送するポンプ１０７が設けられている。第１の精密ろ過膜装置１０２は膜脱気装置１０３（後述）の上流に設けられているが、膜脱気装置１０３の下流、すなわち膜脱気装置１０３とイオン交換装置１０４（後述）との間に設けられてもよく、あるいは、膜脱気装置１０３の上流と、膜脱気装置１０３とイオン交換装置１０４との間の両方に設けられてもよい。 (First subsystem 100)
The first subsystem 100 includes a receiving tank 101 that receives the NMP aqueous solution to be processed collected as described above. The NMP aqueous solution is supplied to the receiving tank 101 by a first NMP aqueous solution supply line L101 connected to an NMP recovery means (not shown) such as a water scrubber. The receiving tank 101 is connected to a first microfiltration membrane device 102 that removes fine particles contained in the NMP aqueous solution via a second NMP aqueous solution supply line L102. A pump 107 that pumps the NMP aqueous solution is provided on the second NMP aqueous solution supply line L102. The first microfiltration membrane device 102 is provided upstream of the membrane degassing device 103 (described later), but downstream of the membrane degassing device 103, that is, between the membrane degassing device 103 and the ion exchange device 104 (described later). It may be provided between them, or may be provided both upstream of the membrane deaerator 103 and between the membrane deaerator 103 and the ion exchange device 104.
　第１の精密ろ過膜装置１０２は第３のＮＭＰ水溶液供給ラインＬ１０３を介して、ＮＭＰ水溶液の溶存酸素を除去する膜脱気装置１０３と接続されている。後述するように、ＮＭＰ水溶液は浸透気化膜装置２０１に導入される前に１２０℃程度まで加熱される。１２０℃程度まで加熱されたＮＭＰ水溶液では、ＮＭＰがＮＭＰ水溶液中の溶存酸素と結合して酸化する可能性がある。予めＮＭＰ水溶液中の溶存酸素を除去することによって、ＮＭＰの酸化を抑制することができる。溶存酸素の濃度を監視するため、膜脱気装置１０３の入口ラインＬ１０３と出口ラインＬ１０４には溶存酸素計（図示せず）が設けられている。また、膜脱気装置１０３の入口ラインＬ１０３には水分量計と比抵抗計（ともに図示せず）が設けられている。 The first microfiltration membrane device 102 is connected to a membrane deaeration device 103 that removes dissolved oxygen in the NMP aqueous solution via a third NMP aqueous solution supply line L103. As will be described later, the NMP aqueous solution is heated to about 120 ° C. before being introduced into the pervaporation membrane apparatus 201. In an NMP aqueous solution heated to about 120 ° C., NMP may be combined with dissolved oxygen in the NMP aqueous solution and oxidized. By removing the dissolved oxygen in the NMP aqueous solution in advance, the oxidation of NMP can be suppressed. In order to monitor the concentration of dissolved oxygen, a dissolved oxygen meter (not shown) is provided at the inlet line L103 and the outlet line L104 of the membrane deaerator 103. The inlet line L103 of the membrane degassing apparatus 103 is provided with a moisture meter and a specific resistance meter (both not shown).
　膜脱気装置１０３の脱気膜は、ポリオレフィン、ポリテトラフルオロエチレン（ＰＴＦＥ）、テトラフルオロエチレン・パーフルオロアルキルビニルエーテル共重合体（ＰＦＡ）、ポリウレタン、エポキシ樹脂などから形成することができる。ＮＭＰは一部の有機材料を溶解させる性質があるため、脱気膜はポリオレフィン、ＰＴＦＥまたはＰＦＡで形成することが好ましい。脱気膜は非多孔性であることが好ましい。中空糸状の脱気膜の内部を流れるＮＭＰ水溶液の溶存酸素が、真空ポンプ１０９によって負圧にされた脱気膜の外部に移動することによって、脱気、すなわち溶存酸素の除去が行われる。なお、脱気膜の外側（ガス透過側）に窒素ガス等の不活性ガスをスウィープして酸素分圧を下げてもよく、真空法とスウィープ法を併用してもよい。 The deaeration membrane of the membrane deaerator 103 can be formed from polyolefin, polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polyurethane, epoxy resin, or the like. Since NMP has the property of dissolving some organic materials, the degassing membrane is preferably formed of polyolefin, PTFE or PFA. The degassing membrane is preferably non-porous. The dissolved oxygen in the NMP aqueous solution flowing inside the hollow fiber-shaped degassing membrane moves to the outside of the degassing membrane that has been made negative pressure by the vacuum pump 109, whereby degassing, that is, removal of dissolved oxygen is performed. Note that the oxygen partial pressure may be lowered by sweeping an inert gas such as nitrogen gas outside the degassing membrane (gas permeation side), or the vacuum method and the sweep method may be used in combination.
　膜脱気装置１０３は第４のＮＭＰ水溶液供給ラインＬ１０４を介して、ＮＭＰ水溶液のイオン成分を除去するイオン交換装置１０４と接続されている。イオン交換装置１０４にはアニオン交換樹脂もしくはカチオン交換樹脂が単床で、または、アニオン交換樹脂とカチオン交換樹脂が混床もしくは複層床で充填されている。なお、イオン交換樹脂の種類は、ゲル型、ＭＲ型のいずれでもよい。ヒータ１０８は、ＮＭＰ水溶液がイオン交換に適した温度でイオン交換装置１０４に供給されるように、ＮＭＰ水溶液を加熱する場合もある。イオン交換装置１０４は第５のＮＭＰ水溶液供給ラインＬ１０５を介して第２の精密ろ過膜装置１０５と接続されている。第２の精密ろ過膜装置１０５はイオン交換装置１０４から流出する可能性のある樹脂を捕捉し、樹脂の下流への流出を防止する。第２の精密ろ過膜装置１０５は第６のＮＭＰ水溶液供給ラインＬ１０６を介して、原液槽１０６と接続されている。原液槽１０６は、膜脱気装置１０３とイオン交換装置１０４で処理されたＮＭＰ水溶液を受け入れ、受け入れたＮＭＰ水溶液を浸透気化膜装置２０１に供給する。以下、原液槽１０６に貯留され、浸透気化膜装置２０１に供給されるＮＭＰ水溶液をＮＭＰ原液という場合がある。 The membrane deaerator 103 is connected to an ion exchange device 104 that removes ion components of the NMP aqueous solution via a fourth NMP aqueous solution supply line L104. The ion exchange device 104 is filled with an anion exchange resin or a cation exchange resin in a single bed, or an anion exchange resin and a cation exchange resin in a mixed bed or a multilayer bed. The type of ion exchange resin may be either gel type or MR type. The heater 108 may heat the NMP aqueous solution so that the NMP aqueous solution is supplied to the ion exchange device 104 at a temperature suitable for ion exchange. The ion exchange device 104 is connected to the second microfiltration membrane device 105 via the fifth NMP aqueous solution supply line L105. The second microfiltration membrane device 105 captures the resin that may flow out of the ion exchange device 104 and prevents the resin from flowing downstream. The second microfiltration membrane device 105 is connected to the stock solution tank 106 via a sixth NMP aqueous solution supply line L106. The stock solution tank 106 receives the NMP aqueous solution processed by the membrane degassing device 103 and the ion exchange device 104, and supplies the received NMP aqueous solution to the pervaporation membrane device 201. Hereinafter, the NMP aqueous solution stored in the stock solution tank 106 and supplied to the pervaporation membrane device 201 may be referred to as an NMP stock solution.
　イオン交換装置１０４の入口ラインＬ１０４と出口ラインＬ１０５には比抵抗計（図示せず）が設けられている。イオン交換装置１０４で処理されたＮＭＰ水溶液の比抵抗が所定の値より小さい場合、すなわちイオン成分が十分に除去されないときは、イオン交換装置１０４を通るループに沿ってＮＭＰ水溶液を循環させることができる。具体的には、第５のＮＭＰ水溶液供給ラインＬ１０５から分岐して受槽１０１に接続された戻りラインＬ１０７が設けられている。通常は第５のＮＭＰ水溶液供給ラインＬ１０５の弁Ｖ１０１が開けられ、戻りラインＬ１０７の弁Ｖ１０２が閉じられているが、ＮＭＰ水溶液の比抵抗が所定の値より小さい場合は第５のＮＭＰ水溶液供給ラインＬ１０５の弁Ｖ１０１を閉じ、戻りラインＬ１０７の弁Ｖ１０２を開く。これによって、受槽１０１、第１の精密ろ過膜装置１０２、膜脱気装置１０３、イオン交換装置１０４を通る循環ループが形成される。ＮＭＰ水溶液がこの循環ループに沿って流れることで、ＮＭＰ水溶液に含まれるイオン成分が十分に除去される。 The resistivity meter (not shown) is provided in the inlet line L104 and the outlet line L105 of the ion exchange device 104. When the specific resistance of the NMP aqueous solution processed by the ion exchange device 104 is smaller than a predetermined value, that is, when the ion component is not sufficiently removed, the NMP aqueous solution can be circulated along a loop passing through the ion exchange device 104. . Specifically, a return line L107 branched from the fifth NMP aqueous solution supply line L105 and connected to the receiving tank 101 is provided. Normally, the valve V101 of the fifth NMP aqueous solution supply line L105 is opened and the valve V102 of the return line L107 is closed. However, if the specific resistance of the NMP aqueous solution is smaller than a predetermined value, the fifth NMP aqueous solution supply line The valve V101 of L105 is closed and the valve V102 of the return line L107 is opened. As a result, a circulation loop is formed that passes through the receiving tank 101, the first microfiltration membrane device 102, the membrane deaeration device 103, and the ion exchange device 104. When the NMP aqueous solution flows along this circulation loop, the ion component contained in the NMP aqueous solution is sufficiently removed.
　なお、前述の膜脱気装置１０３で処理されたＮＭＰ水溶液の溶存酸素が所定の値より大きい場合、すなわち溶存酸素が十分に除去されないときも、前述のイオン交換装置１０４を通るループに沿ってＮＭＰ水溶液を循環させることができる。これにより、ＮＭＰ水溶液に含まれる溶存酸素も十分に除去される。 Note that when the dissolved oxygen in the NMP aqueous solution treated by the membrane degassing device 103 is larger than a predetermined value, that is, when the dissolved oxygen is not sufficiently removed, the NMP along the loop passing through the ion exchange device 104 described above. The aqueous solution can be circulated. Thereby, the dissolved oxygen contained in the NMP aqueous solution is also sufficiently removed.
　（第２のサブシステム２００）
　微粒子とイオン成分が除去され原液槽１０６に貯蔵されたＮＭＰ原液は次に第２のサブシステム２００に供給され、ほとんどの水分が除去されたＮＭＰ濃縮液が生成される。原液槽１０６は第７のＮＭＰ水溶液供給ラインＬ２０１を介して、浸透気化膜装置２０１に接続されている。第７のＮＭＰ水溶液供給ラインＬ２０１にはポンプ２２４と弁Ｖ２０１が設けられている。第７のＮＭＰ水溶液供給ラインＬ２０１には外部蒸気を用いた第１のヒータ２０５と、第１のヒータ２０５の上流（一次側）に位置する廃熱回収熱交換器２０６と、が設置されており、これらの第１のヒータ２０５及び廃熱回収熱交換器２０６によってＮＭＰ水溶液は１２０℃程度まで加熱される。浸透気化膜装置２０１に供給されるＮＭＰ水溶液を１２０℃程度まで加熱することで、浸透気化膜装置２０１の脱水性能を高めることができる。廃熱回収熱交換器２０６は、第７のＮＭＰ水溶液供給ラインＬ２０１を流れるＮＭＰ水溶液と、ＮＭＰ濃縮液排出ラインＬ２０４を流れるＮＭＰ濃縮液との間で熱交換を行う。第１のヒータ２０５は外部の蒸気源（図示せず）から供給される蒸気によってＮＭＰ水溶液を加熱する。第１のヒータ２０５の蒸気供給ラインには蒸気供給量を調整するための弁Ｖ２０２が設けられている。第１のヒータ２０５の下流には温度警報表示器２２３が設けられている。温度警報表示器２２３で検出された温度に基づき弁Ｖ２０２の開度が調整され、ＮＭＰ水溶液の温度が１２０℃程度に制御される。第７のＮＭＰ水溶液供給ラインＬ２０１の廃熱回収熱交換器２０６の上流には流量警報表示器２２５が設けられている。流量警報表示器２２５で検出された流量に基づき弁Ｖ２０１の開度が調整され、ＮＭＰ水溶液の流量が所定の範囲内に制御される。 (Second subsystem 200)
The NMP stock solution from which fine particles and ionic components have been removed and stored in the stock solution tank 106 is then supplied to the second subsystem 200 to generate an NMP concentrated solution from which most of the water has been removed. The stock solution tank 106 is connected to the pervaporation membrane device 201 via a seventh NMP aqueous solution supply line L201. The seventh NMP aqueous solution supply line L201 is provided with a pump 224 and a valve V201. The seventh NMP aqueous solution supply line L201 is provided with a first heater 205 using external steam and a waste heat recovery heat exchanger 206 located upstream (primary side) of the first heater 205. The NMP aqueous solution is heated to about 120 ° C. by the first heater 205 and the waste heat recovery heat exchanger 206. By heating the NMP aqueous solution supplied to the pervaporation membrane device 201 to about 120 ° C., the dehydration performance of the pervaporation membrane device 201 can be enhanced. The waste heat recovery heat exchanger 206 performs heat exchange between the NMP aqueous solution flowing through the seventh NMP aqueous solution supply line L201 and the NMP concentrated solution flowing through the NMP concentrated liquid discharge line L204. The first heater 205 heats the NMP aqueous solution with steam supplied from an external steam source (not shown). The steam supply line of the first heater 205 is provided with a valve V202 for adjusting the steam supply amount. A temperature alarm indicator 223 is provided downstream of the first heater 205. The opening degree of the valve V202 is adjusted based on the temperature detected by the temperature alarm indicator 223, and the temperature of the NMP aqueous solution is controlled to about 120 ° C. A flow rate alarm indicator 225 is provided upstream of the waste heat recovery heat exchanger 206 in the seventh NMP aqueous solution supply line L201. The opening degree of the valve V201 is adjusted based on the flow rate detected by the flow rate alarm indicator 225, and the flow rate of the NMP aqueous solution is controlled within a predetermined range.
　浸透気化膜装置２０１は直列に接続された複数の浸透気化膜モジュールを有している。本実施形態では３台の浸透気化膜モジュール、すなわち上流から下流に向けて第１の浸透気化膜モジュール２０２、第２の浸透気化膜モジュール２０３、第３の浸透気化膜モジュール２０４が直列に接続されているが、台数は３台に限定されない。第１の浸透気化膜モジュール２０２は第１の接続ラインＬ２０２を介して第２の浸透気化膜モジュール２０３に接続されている。第２の浸透気化膜モジュール２０３は第２の接続ラインＬ２０３を介して第３の浸透気化膜モジュール２０４に接続されている。第１～第３の浸透気化膜装置２０２，２０３，２０４は分離膜（浸透気化膜）２０２ｃ、２０３ｃ、２０４ｃによって、上流側の濃縮室２０２ａ，２０３ａ，２０４ａと下流側の透過室２０２ｂ，２０３ｂ，２０４ｂとに区画されている。分離膜２０２ｃ，２０３ｃ，２０４ｃは水に対する親和性を有しているため、水をＮＭＰよりも大きな透過速度で分離膜２０２ｃ，２０３ｃ，２０４ｃを透過させる。透過室２０２ｂ，２０３ｂ，２０４ｂ側に負圧を印加することで、透過速度の大きい水が透過速度の小さい少量のＮＭＰともに蒸気（気相）の形態で透過室２０２ｂ，２０３ｂ，２０４ｂに移動し、ほとんどのＮＭＰは濃縮室２０２ａ，２０３ａ，２０４ａに残存する。この原理を用いてＮＭＰ水溶液から水が分離される。第３の浸透気化膜モジュール２０４の出口では、ＮＭＰ濃度が９９．９９％程度まで高められたＮＭＰ濃縮液（水分は０．０１％未満）が得られる。 The pervaporation membrane device 201 has a plurality of pervaporation membrane modules connected in series. In the present embodiment, three pervaporation membrane modules, that is, a first pervaporation membrane module 202, a second pervaporation membrane module 203, and a third pervaporation membrane module 204 are connected in series from upstream to downstream. However, the number is not limited to three. The first pervaporation membrane module 202 is connected to the second pervaporation membrane module 203 via the first connection line L202. The second pervaporation membrane module 203 is connected to the third pervaporation membrane module 204 via the second connection line L203. The first to third pervaporation membrane devices 202, 203, 204 are separated by upstream separation chambers 202 a, 203 a, 204 a and downstream permeation chambers 202 b, 203 b, by separation membranes (permeation vaporization membranes) 202 c, 203 c, 204 c. 204b. Since the separation membranes 202c, 203c, and 204c have an affinity for water, the water is allowed to permeate the separation membranes 202c, 203c, and 204c at a higher transmission rate than NMP. By applying negative pressure to the permeation chambers 202b, 203b, and 204b, water having a high permeation rate moves to the permeation chambers 202b, 203b, and 204b in the form of vapor (gas phase) together with a small amount of NMP having a low permeation rate, Most NMP remains in the concentration chambers 202a, 203a, 204a. Using this principle, water is separated from the aqueous NMP solution. At the outlet of the third pervaporation membrane module 204, an NMP concentrated liquid (moisture is less than 0.01%) in which the NMP concentration is increased to about 99.99% is obtained.
　ＮＭＰ水溶液は第１～第３の浸透気化膜モジュール２０２，２０３，２０４を順次流通し、徐々にＮＭＰ水溶液中の水分が除去される。上述のとおり、水分の除去効率を維持するため、第１の接続ラインＬ２０２と第２の接続ラインＬ２０３にはそれぞれ、第２のヒータ２０７と第３のヒータ２０８が設けられている。第２及び第３のヒータ２０７，２０８は第１のヒータ２０５と同様、熱交換器であり、外部の蒸気源から供給される蒸気によってＮＭＰ水溶液を１２０℃程度まで加熱する。第２及び第３のヒータ２０７，２０８の蒸気供給ラインにはそれぞれ、蒸気供給量を調整するための弁Ｖ２０３，Ｖ２０４が設けられている。第３の浸透気化膜モジュール２０４から排出されたＮＭＰ濃縮水はＮＭＰ濃縮液排出ラインＬ２０４を通って第３のサブシステム３００の中継槽３０１に供給される。上述のように、ＮＭＰ濃縮液排出ラインＬ２０４を流れるＮＭＰ濃縮液は、廃熱回収式熱交換器２０６によって、第７のＮＭＰ水溶液供給ラインＬ２０１を流れるＮＭＰ水溶液との間で熱交換を行い、ＮＭＰ水溶液を予熱する。 The NMP aqueous solution sequentially flows through the first to third pervaporation membrane modules 202, 203, and 204, and moisture in the NMP aqueous solution is gradually removed. As described above, in order to maintain the moisture removal efficiency, the first connection line L202 and the second connection line L203 are provided with the second heater 207 and the third heater 208, respectively. Similar to the first heater 205, the second and third heaters 207 and 208 are heat exchangers, and heat the NMP aqueous solution to about 120 ° C. by steam supplied from an external steam source. The steam supply lines of the second and third heaters 207 and 208 are provided with valves V203 and V204 for adjusting the steam supply amount, respectively. The NMP concentrated water discharged from the third pervaporation membrane module 204 is supplied to the relay tank 301 of the third subsystem 300 through the NMP concentrated liquid discharge line L204. As described above, the NMP concentrated liquid flowing through the NMP concentrated liquid discharge line L204 is subjected to heat exchange with the NMP aqueous solution flowing through the seventh NMP aqueous solution supply line L201 by the waste heat recovery heat exchanger 206. Preheat the aqueous solution.
　ＮＭＰ濃縮液排出ラインＬ２０４から分岐して原液槽１０６に接続されるＮＭＰ濃縮液の戻りラインＬ２１５が設けられている。通常はＮＭＰ濃縮液排出ラインＬ２０４の弁Ｖ２０５が開かれ、戻りラインＬ２１５の弁Ｖ２０６が閉じられ、ＮＭＰ濃縮液は中継槽３０１に供給される。一方、中継槽３０１にＮＭＰ濃縮液を供給できない場合などは弁Ｖ２０５が閉じられ、弁Ｖ２０６が開かれて、ＮＭＰ濃縮液が原液槽１０６に戻される。なお、ＮＭＰ濃縮液を原液槽１０６に返送する場合は、戻りラインＬ２１５に設けられた冷却器２２６によって、ＮＭＰ濃縮液の温度がＮＭＰ水溶液（原液）の温度と同程度になるように冷却水により冷却する。 An NMP concentrate return line L215 branched from the NMP concentrate discharge line L204 and connected to the stock solution tank 106 is provided. Normally, the valve V205 of the NMP concentrate discharge line L204 is opened, the valve V206 of the return line L215 is closed, and the NMP concentrate is supplied to the relay tank 301. On the other hand, when the NMP concentrate cannot be supplied to the relay tank 301, the valve V205 is closed, the valve V206 is opened, and the NMP concentrate is returned to the stock tank 106. When returning the NMP concentrated solution to the stock solution tank 106, the cooler 226 provided in the return line L215 is cooled by cooling water so that the temperature of the NMP concentrated solution becomes approximately the same as the temperature of the NMP aqueous solution (stock solution). Cooling.
　第１～第３の浸透気化膜モジュール２０２，２０３，２０４の透過室２０２ｂ，２０３ｂ，２０４ｂはそれぞれ第１～第３の透過液排出ラインＬ２０６，Ｌ２０９，Ｌ２１２によって第１～第３の透過液タンク２１４，２１５，２１６に接続されている。気相の水と少量のＮＭＰは冷却水またはブラインによって凝縮され、第１～第３の透過液タンク２１４，２１５，２１６の底部に収集される。具体的には冷却水またはブラインは第１～第３の透過液タンク２１４，２１５，２１６の周囲を覆う冷却ジャケット（図示せず）を流れて気相の水及びＮＭＰを保冷し、さらに冷却ラインＬ２０７，Ｌ２１０、Ｌ２１３を通って、第１～第３の透過液排出ラインＬ２０６，Ｌ２０９，Ｌ２１２に設けられた第１～第３の熱交換器２１１，２１２，２１３に供給され、気相の水及びＮＭＰを凝縮する。ブラインの温度は０～－２０℃程度が好ましい。第１～第３の透過液タンク２１４，２１５，２１６の底部にはそれぞれ第１～第３の凝縮水排出ラインＬ２０８，Ｌ２１１，Ｌ２１４が接続されており、第１～第３の凝縮水排出ラインＬ２０８，Ｌ２１１，Ｌ２１４にはそれぞれ第１～第３の排出ポンプ２２０，２２１，２２２が設けられている。凝縮された水と少量のＮＭＰは第１～第３の排出ポンプ２２０，２２１，２２２によって、第１～第３の透過液タンク２１４，２１５，２１６から排出される。また、第１～第３の透過液タンク２１４，２１５，２１６の上部には透過室２０１ｂ，２０２ｂ，２０３ｂに負圧を印加する第１～第３の真空ポンプ２１７，２１８，２１９が設けられている。 The permeation chambers 202b, 203b, 204b of the first to third pervaporation membrane modules 202, 203, 204 are respectively connected to the first to third permeate tanks by the first to third permeate discharge lines L206, L209, L212. 214, 215, 216. Vapor phase water and a small amount of NMP are condensed by cooling water or brine and collected at the bottom of the first to third permeate tanks 214, 215, 216. Specifically, the cooling water or brine flows through a cooling jacket (not shown) covering the periphery of the first to third permeate tanks 214, 215, and 216 to keep the vapor phase water and NMP cold, and further to the cooling line. Gas phase water is supplied to the first to third heat exchangers 211, 212, and 213 provided in the first to third permeate discharge lines L206, L209, and L212 through L207, L210, and L213. And condensing NMP. The temperature of the brine is preferably about 0 to -20 ° C. First to third condensed water discharge lines L208, L211, and L214 are connected to the bottoms of the first to third permeate tanks 214, 215, and 216, respectively, and the first to third condensed water discharge lines are connected. L208, L211, and L214 are provided with first to third discharge pumps 220, 221, and 222, respectively. The condensed water and a small amount of NMP are discharged from the first to third permeate tanks 214, 215, and 216 by the first to third discharge pumps 220, 221, and 222, respectively. Further, first to third vacuum pumps 217, 218, and 219 for applying a negative pressure to the permeation chambers 201b, 202b, and 203b are provided above the first to third permeate tanks 214, 215, and 216, respectively. Yes.
　最上流の浸透気化膜モジュール、すなわち第１の浸透気化膜モジュール２０２はＣＨＡ型、Ｔ型、Ｙ型またはＭＯＲ型のゼオライトからなる浸透気化膜２０２ｃを有している。最上流の浸透気化膜モジュール以外の浸透気化膜モジュール、すなわち第２及び第３の浸透気化膜モジュール２０３，２０４はＡ型ゼオライトからなる浸透気化膜２０３ｃ，２０４ｃを有している。Ａ型ゼオライトは、比較的安価で脱水性能が高いものの、水分濃度が高いＮＭＰ水溶液を処理する場合に、リークや性能低下が生じやすい。これに対し、Ａ型以外のゼオライトは上述の環境でより長期間性能を保持することができる。このため、１０～２０重量％の水を含有するＮＭＰ水溶液を処理する第１の浸透気化膜モジュール２０２の浸透気化膜２０２ｃはＣＨＡ型、Ｔ型、Ｙ型またはＭＯＲ型のゼオライトを用い、水分含有量の少ないＮＭＰ水溶液を処理する第２及び第３の浸透気化膜モジュール２０３，２０４の浸透気化膜２０３ｃ，２０４ｃはＡ型ゼオライトを用いている。なお、第１の浸透気化膜モジュール２０２を構成する複数の浸透気化膜のすべてがＣＨＡ型、Ｔ型、Ｙ型またはＭＯＲ型のゼオライトからなっている必要はなく、一部の膜がＡ型ゼオライトからなっていてもよい。 The most upstream pervaporation membrane module, that is, the first pervaporation membrane module 202 has a permeation vaporization membrane 202c made of CHA type, T type, Y type or MOR type zeolite. The permeate vaporization membrane modules other than the most upstream pervaporation membrane module, that is, the second and third pervaporation membrane modules 203 and 204 have permeate vaporization membranes 203c and 204c made of A-type zeolite. Although A-type zeolite is relatively inexpensive and has high dehydration performance, leaks and performance degradation are likely to occur when processing an NMP aqueous solution having a high water concentration. On the other hand, zeolites other than the A type can maintain performance for a longer period in the above-described environment. Therefore, the pervaporation membrane 202c of the first pervaporation membrane module 202 for treating the NMP aqueous solution containing 10 to 20% by weight of water uses CHA type, T type, Y type or MOR type zeolite, and contains water. A-type zeolite is used for the pervaporation membranes 203c and 204c of the second and third pervaporation membrane modules 203 and 204 for treating a small amount of NMP aqueous solution. Note that it is not necessary that all of the plurality of pervaporation membranes constituting the first pervaporation membrane module 202 are CHA type, T type, Y type, or MOR type zeolite, and some membranes are A type zeolite. It may consist of
　第３の透過液排出ラインＬ２１２には冷却器２０９とメカニカルブースターポンプ２１０が設けられている。冷却器２０９は第３の浸透気化膜モジュール２０４から排出された透過液を予冷する。メカニカルブースターポンプ２１０および冷却器２０９は第３の浸透気化膜モジュール２０４の透過室２０４ｂに大きな負圧を印加するために設けられている。第３の浸透気化膜モジュール２０４に供給されるＮＭＰ水溶液の水分含有量は非常に少ないため、第３の真空ポンプ２１９に加えてメカニカルブースターポンプ２１０で十分な負圧を印加することで、水をＮＭＰ水溶液から効率的に分離することができる。冷却器２０９及びメカニカルブースターポンプ２１０は省略することができる。また、冷却器２０９とメカニカルブースターポンプ２１０との間に、冷却器２０９で凝縮された凝縮水を貯留するためのポッド（図示せず）を設けることもできる。 The third permeate discharge line L212 is provided with a cooler 209 and a mechanical booster pump 210. The cooler 209 precools the permeate discharged from the third pervaporation membrane module 204. The mechanical booster pump 210 and the cooler 209 are provided to apply a large negative pressure to the permeation chamber 204b of the third pervaporation membrane module 204. Since the water content of the NMP aqueous solution supplied to the third pervaporation membrane module 204 is very small, water can be removed by applying a sufficient negative pressure with the mechanical booster pump 210 in addition to the third vacuum pump 219. It can be efficiently separated from the NMP aqueous solution. The cooler 209 and the mechanical booster pump 210 can be omitted. Further, a pod (not shown) for storing the condensed water condensed by the cooler 209 can be provided between the cooler 209 and the mechanical booster pump 210.
　第２及び第３の浸透気化膜モジュール２０３，２０４の透過液は浸透気化膜装置２０１の上流側に回収される。具体的には第２及び第３の透過液排出ラインＬ２１１、Ｌ２１４は透過液回収ラインＬ２０５に接続され、透過液回収ラインＬ２０５は原液槽１０６に接続されている。第２及び第３の透過液排出ラインＬ２１１、Ｌ２１４から排出される透過液は第１の透過液排出ラインＬ２０８から排出される透過液と比べＮＭＰの含有量が高いため、これを回収することで、ＮＭＰの回収率を高めることができる。透過液が回収される浸透気化膜モジュールは第２及び第３の浸透気化膜モジュール２０３，２０４に限定されず、少なくとも最下流の浸透気化膜モジュール（第３の浸透気化膜モジュール２０４）の透過液が浸透気化膜装置２０１の上流側に回収されればよい。透過液は受槽１０１に回収してもよく、透過液回収ラインＬ２０５に分岐ライン（図示せず）を設けることによって、原液槽１０６と受槽１０１とに選択的に回収してもよい。 The permeated liquid of the second and third pervaporation membrane modules 203 and 204 is collected on the upstream side of the pervaporation membrane device 201. Specifically, the second and third permeate discharge lines L211 and L214 are connected to the permeate recovery line L205, and the permeate recovery line L205 is connected to the stock solution tank. The permeate discharged from the second and third permeate discharge lines L211 and L214 has a higher NMP content than the permeate discharged from the first permeate discharge line L208. , NMP recovery rate can be increased. The permeate vaporization membrane module from which the permeate is collected is not limited to the second and third pervaporation membrane modules 203 and 204, and at least the permeate vaporization membrane module (third pervaporation membrane module 204) at the most downstream side. May be recovered upstream of the pervaporation membrane device 201. The permeate may be collected in the receiving tank 101 or may be selectively collected in the stock liquid tank 106 and the receiving tank 101 by providing a branch line (not shown) in the permeate collecting line L205.
　（第３のサブシステム３００）
　第２のサブシステム２００で生成されたＮＭＰ濃縮液は、ほとんどの水分が除去されている。しかし、ＮＭＰ濃縮液は色度成分や浸透気化膜モジュールから溶出した浸透気化膜２０２ｃ，２０３ｃ，２０４ｃの微粒子およびイオン成分をわずかに含むため、さらに浸透気化膜装置２０１の下流に位置する第３のサブシステム３００で蒸留されてＮＭＰ精製液が生成される。なお、以下に述べる第３のサブシステム３００は単蒸留方式を用いているが、ＮＭＰ濃縮液を蒸留することが可能な限り蒸留方法は限定されない。例えば、精密蒸留方式を用いることもできる。ただし、エネルギー消費が少ないこと、装置サイズが小さいこと、操作が簡単であることなどの理由から単蒸留方式が好ましい。また、単蒸留方式の中でも、本実施形態で用いている減圧単蒸留方式は熱劣化を防止できる観点から特に望ましい。 (Third subsystem 300)
Most of the water is removed from the NMP concentrate produced by the second subsystem 200. However, the NMP concentrate contains a small amount of fine particles and ionic components of the pervaporation membranes 202c, 203c, and 204c eluted from the chromaticity component and the pervaporation membrane module. NMP purified solution is produced by distillation in the subsystem 300. Although the third subsystem 300 described below uses a simple distillation method, the distillation method is not limited as long as the NMP concentrated solution can be distilled. For example, a precision distillation method can also be used. However, the simple distillation method is preferred because it consumes less energy, the apparatus size is small, and the operation is simple. Among the simple distillation methods, the reduced pressure simple distillation method used in this embodiment is particularly desirable from the viewpoint of preventing thermal deterioration.
　前述のように、ＮＭＰ濃縮液は一旦中継槽３０１に貯留される。第３のサブシステム３００は第２のサブシステム２００から独立したサブシステムであり、例えば、第２のサブシステム２００の運転中に第３のサブシステム３００の運転を一時的に停止するといった運用がなされることがある。このため、中継槽３０１を設けることで、第２のサブシステム２００と第３のサブシステム３００を、互いの独立性を維持しながらより弾力的に運用することが可能となる。中継槽３０１は第１のＮＭＰ濃縮液供給ラインＬ３０１を介して再生器３０２に接続されている。第１のＮＭＰ濃縮液供給ラインＬ３０１にはポンプ３０６と弁Ｖ３０１が設けられている。再生器３０２は熱交換器であり、後述する蒸発缶３０３で蒸発したＮＭＰ濃縮液（以下、ＮＭＰ精製ガスという）との間で熱交換を行う。これによって、蒸発缶３０３の熱負荷を低減することができる。再生器３０２は第２のＮＭＰ濃縮液供給ラインＬ３０２を介して蒸発缶３０３に接続されている。蒸発缶３０３は外部の蒸気源（図示せず）から供給される蒸気によってＮＭＰ濃縮液を加熱し蒸発させる。蒸発缶３０３の蒸気供給ラインには蒸気供給量を調整するための弁Ｖ３０２が設けられている。蒸発缶３０３の底部には高温の液相のＮＭＰ濃縮液が滞留し、その上部に微粒子が除去された気相のＮＭＰ精製ガスが形成される。液相のＮＭＰ濃縮液に含まれる色度成分も蒸発しにくい性質のため、蒸発缶３０３の底部に蓄積される。なお、本実施形態における蒸発缶３０３としては、液膜流下式の蒸発缶を例に挙げて以下に説明するが、液膜流下式以外の蒸発缶、例えばフラッシュ式、カランドリア式などの蒸発缶を用いても良い。蒸発缶３０３の底部と頂部には循環ラインＬ３０３が接続されており、液相のＮＭＰ濃縮液を取り出して蒸発缶３０３に戻し、液膜流下にて再度加熱するサイクルが繰り返される。蒸気取り出し缶３０４（後述）の底部には、循環ラインＬ３０３と合流するＮＭＰ濃縮液取り出しラインＬ３０６が設けられている。蒸気取り出し缶３０４の底部に滞留するＮＭＰ濃縮液も、ＮＭＰ濃縮液取り出しラインＬ３０６と循環ラインＬ３０３を通って蒸発缶３０３に戻され、再度加熱される。循環ラインＬ３０３には循環ポンプ３０７と弁Ｖ３０３が設けられている。循環ラインＬ３０３からは、弁Ｖ３０４が設けられたＮＭＰ濃縮液の排出ラインＬ３０９が分岐している。 As described above, the NMP concentrate is temporarily stored in the relay tank 301. The third subsystem 300 is an independent subsystem from the second subsystem 200. For example, the operation of temporarily stopping the operation of the third subsystem 300 during the operation of the second subsystem 200 is performed. Sometimes done. For this reason, by providing the relay tank 301, it becomes possible to operate the second subsystem 200 and the third subsystem 300 more flexibly while maintaining mutual independence. The relay tank 301 is connected to the regenerator 302 via the first NMP concentrate supply line L301. The first NMP concentrate supply line L301 is provided with a pump 306 and a valve V301. The regenerator 302 is a heat exchanger, and performs heat exchange with an NMP concentrated liquid (hereinafter referred to as NMP purified gas) evaporated in an evaporator 303 described later. Thereby, the thermal load of the evaporator 303 can be reduced. The regenerator 302 is connected to the evaporator 303 via the second NMP concentrate supply line L302. The evaporator 303 heats and evaporates the NMP concentrated liquid with steam supplied from an external steam source (not shown). The vapor supply line of the evaporator 303 is provided with a valve V302 for adjusting the vapor supply amount. A high temperature liquid phase NMP concentrate stays at the bottom of the evaporator 303, and a gas phase NMP purified gas from which fine particles have been removed is formed at the top. The chromaticity component contained in the liquid phase NMP concentrate is also difficult to evaporate, and is therefore accumulated at the bottom of the evaporator 303. The evaporator 303 in the present embodiment will be described below by taking a liquid film flow-down type evaporator as an example, but an evaporator other than the liquid film flow-down type, for example, an evaporator such as a flash type or a calandria type can be used. It may be used. A circulation line L303 is connected to the bottom and top of the evaporator 303, and a cycle of taking out the liquid phase NMP concentrate and returning it to the evaporator 303 and heating it again under the flow of the liquid film is repeated. At the bottom of the vapor take-out can 304 (described later), an NMP concentrated liquid take-out line L306 that joins with the circulation line L303 is provided. The NMP concentrate staying at the bottom of the vapor takeout can 304 is also returned to the evaporator 303 through the NMP concentrate takeout line L306 and the circulation line L303 and heated again. The circulation line L303 is provided with a circulation pump 307 and a valve V303. From the circulation line L303, an NMP concentrate discharge line L309 provided with a valve V304 branches.
　蒸発缶３０３のＮＭＰ精製ガスは蒸発缶３０３の気相部から取り出され、第１のＮＭＰ精製ガス取り出しラインＬ３０４によって蒸気取り出し缶３０４に取り出される。蒸気取り出し缶３０４は第２のＮＭＰ精製ガス取り出しラインＬ３０５を介して再生器３０２と接続されている。ＮＭＰ精製ガスの熱は再生器３０２で液相のＮＭＰ濃縮液と熱交換される。再生器３０２を出たＮＭＰ精製ガスはさらに第３のＮＭＰ精製ガス取り出しラインＬ３０７によってコンデンサ３０５に導入され、冷却水によって凝縮されてＮＭＰ精製水となる。コンデンサ３０５の出口にはＮＭＰ精製水取り出し配管Ｌ３０８が接続されている。ＮＭＰ精製水は、ＮＭＰ精製水取り出し配管Ｌ３０８に設けられたポンプ３０８によって、ＮＭＰ水溶液の精製システム１の系外に排出される。 The NMP purified gas in the evaporator 303 is taken out from the vapor phase portion of the evaporator 303 and taken out to the vapor takeout can 304 by the first NMP purified gas takeout line L304. The steam take-out can 304 is connected to the regenerator 302 via the second NMP purified gas take-out line L305. The heat of the NMP purified gas is heat-exchanged with the liquid phase NMP concentrate in the regenerator 302. The NMP purified gas exiting the regenerator 302 is further introduced into the condenser 305 by the third NMP purified gas take-out line L307 and condensed by the cooling water to become NMP purified water. An NMP purified water take-out pipe L308 is connected to the outlet of the capacitor 305. NMP purified water is discharged out of the NMP aqueous solution purification system 1 by a pump 308 provided in the NMP purified water take-out pipe L308.
　（不活性ガス供給手段）
　本実施形態のＮＭＰ水溶液の精製システム１はさらに、容器の気相部を不活性ガスで充填する不活性ガス供給手段を備えている。上述のように、浸透気化膜装置２０１の上流及び下流にはＮＭＰ水溶液、ＮＭＰ濃縮液またはＮＭＰ精製液が貯留される様々な容器が設けられている。これらの容器のいくつかは、内部にＮＭＰ水溶液、ＮＭＰ濃縮液またはＮＭＰ精製液と、気相部との界面が形成される。この条件を満たす容器として以下が挙げられる。 (Inert gas supply means)
The NMP aqueous solution purification system 1 of this embodiment further includes an inert gas supply means for filling the gas phase portion of the container with an inert gas. As described above, various containers for storing the NMP aqueous solution, the NMP concentrated solution, or the NMP purified solution are provided upstream and downstream of the pervaporation membrane device 201. In some of these containers, an interface between an NMP aqueous solution, an NMP concentrated solution or an NMP purified solution, and a gas phase part is formed. Examples of containers that satisfy this condition include the following.
　（１）ＮＭＰ水溶液の受槽１０１
　（２）原液槽１０６
　（３）中継槽３０１
　（４）再生器３０２
　（５）蒸発缶３０３
　（６）蒸気取り出し缶３０４
　（７）コンデンサ３０５
　従来のこれらの容器１０１，１０６，３０１～３０５の気相部は空気で形成されていた。しかし、発明者はこれらの容器（不活性ガス供給手段に関する以下の記載では、容器は容器１０１，１０６，３０１～３０５を意味する）に空気が充填されている場合、ＮＭＰが気相部の空気と結合して、ＮＭＰの過酸化物（ＮＭＰ－Ｏ－Ｏ－Ｈ；５－ハイドロパーオキソ－１－メチル－２－ピロリドン）が生成されることを見出した。ＮＭＰの過酸化物は蓄積されると爆発の可能性がある。そこで、本実施形態ではこれらの容器に不活性ガス供給手段を設けている。不活性ガスとしては窒素ガスが好ましく、アルゴンガスを用いることもできる。不活性ガス供給手段は以下に述べる不活性ガス供給母管Ｌ４０１と、母管Ｌ４０１から分岐し各容器に不活性ガスを供給する不活性ガス供給ラインと、各不活性ガス供給ライン上に設置されたガスシールユニット、とから構成される。 (1) NMP aqueous solution receiving tank 101
(2) Stock solution tank 106
(3) Relay tank 301
(4) Regenerator 302
(5) Evaporator 303
(6) Steam take-out can 304
(7) Capacitor 305
The gas phase portions of these conventional containers 101, 106, 301 to 305 are formed of air. However, when the inventor has filled these containers (in the following description of the inert gas supply means, the containers mean the containers 101, 106, 301 to 305) with NMP, the NMP is the gas in the gas phase. It was found that an NMP peroxide (NMP-O—O—H; 5-hydroperoxo-1-methyl-2-pyrrolidone) was produced in combination. The accumulation of NMP peroxide may cause an explosion. Therefore, in this embodiment, these containers are provided with inert gas supply means. Nitrogen gas is preferable as the inert gas, and argon gas can also be used. The inert gas supply means is installed on an inert gas supply mother pipe L401 described below, an inert gas supply line that branches from the mother pipe L401 and supplies an inert gas to each vessel, and each inert gas supply line. Gas seal unit.
　具体的には不活性ガスの供給源（図示せず）に不活性ガス供給母管Ｌ４０１が接続され、不活性ガス供給母管Ｌ４０１と受槽１０１、原液槽１０６、中継槽３０１がそれぞれ不活性ガス供給ラインＬ４０２，４０３，４０４で接続されている。不活性ガス供給ラインＬ４０２，４０３，４０４は容器の頂部に接続されている。不活性ガス供給ラインＬ４０２，４０３，４０４にはそれぞれガスシールユニットＵ４０２，Ｕ４０３，Ｕ４０４が設けられている。コンデンサ３０５に接続された真空ポンプ３０９が設けられ、コンデンサ３０５と真空ポンプ３０９との間の配管にスウィープ用の不活性ガス供給ラインＬ４０５が接続されている。不活性ガスは不活性ガス供給ラインＬ４０５からコンデンサ３０５に供給され、さらにラインＬ３０７，Ｌ３０２，Ｌ３０４，Ｌ３０５を通って再生器３０２、蒸発缶３０３及び蒸気取り出し缶３０４にも不活性ガスが供給される。図示は省略するが、再生器３０２、蒸発缶３０３、蒸気取り出し缶３０４にも同様の真空ポンプとスウィープ用の不活性ガス供給ラインを設けることができる。以下、ガスシールユニットＵ４０２，Ｕ４０３，Ｕ４０４を例に説明するが、他のガスシールユニットについても同様である。ガスシールユニットＵ４０２，Ｕ４０３，Ｕ４０４は、下流側の容器の圧力が低下すると自動的に開き、不活性ガスを容器に充填するようにされている。従って、容器内のＮＭＰ水溶液、ＮＭＰ濃縮液及びＮＭＰ精製液の量が低下すると容器の圧力が下がり、ガスシールユニットＵ４０２，Ｕ４０３，Ｕ４０４を介して不活性ガスが容器に補充される。 Specifically, an inert gas supply mother pipe L401 is connected to an inert gas supply source (not shown), and the inert gas supply mother pipe L401, the receiving tank 101, the stock solution tank 106, and the relay tank 301 are each inert gas. They are connected by supply lines L402, 403, and 404. Inert gas supply lines L402, 403, and 404 are connected to the top of the container. Inert gas supply lines L402, 403, and 404 are provided with gas seal units U402, U403, and U404, respectively. A vacuum pump 309 connected to the capacitor 305 is provided, and a sweep inert gas supply line L405 is connected to a pipe between the capacitor 305 and the vacuum pump 309. The inert gas is supplied to the condenser 305 from the inert gas supply line L405, and the inert gas is also supplied to the regenerator 302, the evaporator 303, and the steam take-out can 304 through the lines L307, L302, L304, and L305. . Although not shown, the regenerator 302, the evaporator 303, and the steam take-out can 304 can be provided with a similar vacuum pump and an inert gas supply line for sweeping. Hereinafter, the gas seal units U402, U403, and U404 will be described as an example, but the same applies to other gas seal units. The gas seal units U402, U403, and U404 are automatically opened when the pressure in the downstream container decreases, and are filled with an inert gas. Therefore, when the amount of the NMP aqueous solution, the NMP concentrated liquid, and the NMP purified liquid in the container decreases, the pressure of the container decreases, and the inert gas is replenished to the container through the gas seal units U402, U403, and U404.
　不活性ガスはＮＭＰ水溶液の精製システム１が最初に稼動する際に容器に充填される。このとき、容器の内部は空気で満たされているため、ガスシールユニットＵ４０２，Ｕ４０３，Ｕ４０４を通して不活性ガスを容器に送り込み、容器の内部の空気を強制的に不活性ガスに置換する。 The inert gas is filled into the container when the NMP aqueous solution purification system 1 is first operated. At this time, since the inside of the container is filled with air, the inert gas is fed into the container through the gas seal units U402, U403, U404, and the air inside the container is forcibly replaced with the inert gas.
　容器に不活性ガスを充填することで、ＮＭＰ過酸化物の爆発の可能性を低減できるだけでなく、容器内のＮＭＰ水溶液、ＮＭＰ濃縮液及びＮＭＰ精製液に溶け込む水分量および溶存酸素量を抑えることができる。この結果、浸透気化膜モジュールの負荷を軽減することができる。また、容器内に酸素がほとんど存在しないため、ＮＭＰ水溶液、ＮＭＰ濃縮液及びＮＭＰ精製液の酸化を防止する効果も得られる。 Filling the container with inert gas not only reduces the possibility of explosion of NMP peroxide, but also suppresses the amount of water and dissolved oxygen dissolved in the NMP aqueous solution, NMP concentrate and NMP purified solution in the container. Can do. As a result, the load on the pervaporation membrane module can be reduced. Moreover, since there is almost no oxygen in a container, the effect which prevents the oxidation of NMP aqueous solution, a NMP concentrate, and a NMP refinement | purification liquid is also acquired.
　（実施例）
　容器にＮＭＰ水溶液を充填し、上部を気相としてＮＭＰ水溶液中の過酸化物濃度の経時的な変化を測定した。実施例は気相を窒素ガス（＞９９．９重量％以上）とし、比較例は気相を空気とした。容器内にＮＭＰ水溶液と窒素ガスまたは空気を充填した状態で３０日間放置し、ＮＭＰ過酸化物の濃度をヨウ素滴定法により測定した。結果を表１に示す。このように、気相を窒素に置換することで、ＮＭＰ水溶液中のＮＭＰ過酸化物の濃度がほぼゼロに抑えられることが確認された。 (Example)
The container was filled with an NMP aqueous solution, and the change over time in the peroxide concentration in the NMP aqueous solution was measured using the upper part as a gas phase. In the examples, the gas phase was nitrogen gas (> 99.9% by weight or more), and in the comparative example, the gas phase was air. The container was left for 30 days in a state filled with an NMP aqueous solution and nitrogen gas or air, and the concentration of NMP peroxide was measured by an iodometric titration method. The results are shown in Table 1. Thus, it was confirmed that the concentration of NMP peroxide in the NMP aqueous solution can be suppressed to almost zero by substituting the gas phase with nitrogen.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　本発明のいくつかの好ましい実施形態を詳細に示し、説明したが、添付された請求項の趣旨または範囲から逸脱せずに様々な変更および修正が可能であることを理解されたい。
  Although several preferred embodiments of the present invention have been shown and described in detail, it should be understood that various changes and modifications can be made without departing from the spirit or scope of the appended claims.

Claims (13)

  1. 　ＮＭＰと水とを含むＮＭＰ水溶液の精製システムであって、
    　前記ＮＭＰ水溶液から水を除去してＮＭＰ濃縮液を生成する浸透気化膜装置と、
    　前記浸透気化膜装置の上流または下流に設けられ、前記ＮＭＰ水溶液または前記ＮＭＰ濃縮液が貯留される容器と、
    　前記容器の気相部を不活性ガスで充填する不活性ガス供給手段と、を有するＮＭＰ水溶液の精製システム。     A purification system for an NMP aqueous solution containing NMP and water,
    A pervaporation membrane device that removes water from the aqueous NMP solution to produce an NMP concentrate;
    A container provided upstream or downstream of the pervaporation membrane device and storing the NMP aqueous solution or the NMP concentrated solution;
    An NMP aqueous solution purification system comprising: an inert gas supply unit that fills a gas phase portion of the container with an inert gas.
  2. 　前記浸透気化膜装置の入口に接続されたＮＭＰ水溶液供給ラインと、
    　前記ＮＭＰ水溶液供給ライン上に設置され、前記ＮＭＰ水溶液を加熱するヒータと、を有する、請求項１に記載の精製システム。     An NMP aqueous solution supply line connected to the inlet of the pervaporation membrane device;
    The refining system according to claim 1, further comprising a heater that is installed on the NMP aqueous solution supply line and heats the NMP aqueous solution.
  3. 　前記浸透気化膜装置の出口に接続されたＮＭＰ濃縮液排出ラインと、
    　前記ＮＭＰ水溶液供給ラインの前記ヒータの上流に設置され、前記ＮＭＰ水溶液供給ラインを流れる前記ＮＭＰ水溶液と、前記ＮＭＰ濃縮液排出ラインを流れる前記ＮＭＰ濃縮液との間で熱交換を行う熱交換器と、を有する、請求項２に記載の精製システム。     An NMP concentrate discharge line connected to the outlet of the pervaporation membrane device;
    A heat exchanger installed upstream of the heater of the NMP aqueous solution supply line and performing heat exchange between the NMP aqueous solution flowing through the NMP aqueous solution supply line and the NMP concentrated solution flowing through the NMP concentrated solution discharge line; The purification system according to claim 2.
  4. 　前記浸透気化膜装置は直列に接続された複数の浸透気化膜モジュールを有する、請求項１から３のいずれか１項に記載の精製システム。 The purification system according to any one of claims 1 to 3, wherein the pervaporation membrane device has a plurality of pervaporation membrane modules connected in series.
  5. 　少なくとも最下流の前記浸透気化膜モジュールの透過液を前記浸透気化膜装置の上流側に戻す透過液回収ラインを有する、請求項４に記載の精製システム。 The purification system according to claim 4, further comprising a permeate recovery line for returning the permeate of at least the most downstream permeate vaporization module module to the upstream side of the pervaporation membrane device.
  6. 　最下流の前記浸透気化膜モジュールの透過液排出ラインと、
    　前記透過液排出ライン上に設けられたメカニカルブースターポンプと、を有する、請求項４または５に記載の精製システム。     A permeate discharge line of the most downstream pervaporation membrane module;
    The purification system according to claim 4, further comprising a mechanical booster pump provided on the permeate discharge line.
  7. 　最上流の前記浸透気化膜モジュールはＣＨＡ型、Ｔ型、Ｙ型またはＭＯＲ型のゼオライトからなる浸透気化膜を有し、前記最上流の浸透気化膜モジュール以外の前記浸透気化膜モジュールはＡ型ゼオライトからなる浸透気化膜を有する、請求項４から６のいずれか１項に記載の精製システム。 The most upstream pervaporation membrane module has a permeation vaporization membrane made of CHA type, T type, Y type or MOR type zeolite, and the permeation vaporization membrane module other than the most upstream permeation vaporization membrane module is an A type zeolite. The purification system according to any one of claims 4 to 6, wherein the purification system has a pervaporation membrane.
  8. 　前記浸透気化膜装置の上流に溶存酸素を除去する膜脱気装置を有する、請求項１から７のいずれか１項に記載の精製システム。 The purification system according to any one of claims 1 to 7, further comprising a membrane deaeration device for removing dissolved oxygen upstream of the pervaporation membrane device.
  9. 　前記膜脱気装置と前記浸透気化膜装置との間に位置するイオン交換装置を有する、請求項８に記載の精製システム。 The purification system according to claim 8, further comprising an ion exchange device located between the membrane degassing device and the pervaporation membrane device.
  10. 　前記イオン交換装置と前記浸透気化膜装置との間と、前記膜脱気装置の上流の少なくともいずれかに位置する精密ろ過膜装置を有する、請求項９に記載の精製システム。 The purification system according to claim 9, further comprising a microfiltration membrane device located between at least one of the ion exchange device and the pervaporation membrane device and upstream of the membrane deaeration device.
  11. 　前記浸透気化膜装置の下流に位置し、前記ＮＭＰ濃縮液を蒸留してＮＭＰ精製液を生成する蒸留装置を有する、請求項１から１０のいずれか１項に記載の精製システム。 The purification system according to any one of claims 1 to 10, further comprising a distillation apparatus that is located downstream of the pervaporation membrane apparatus and generates an NMP purified liquid by distilling the NMP concentrated liquid.
  12. 　処理対象のＮＭＰ水溶液の受槽と、
    　前記受槽から供給された前記ＮＭＰ水溶液に含まれる溶存酸素を除去する膜脱気装置と、
    　前記膜脱気装置で処理された前記ＮＭＰ水溶液を受け入れ、前記浸透気化膜装置に前記ＮＭＰ水溶液を供給する原液槽と、
    　前記浸透気化膜装置で濃縮された前記ＮＭＰ濃縮液を受け入れる中継槽と、
    　前記中継槽から供給された前記ＮＭＰ濃縮液を蒸発させてＮＭＰ精製ガスを生成する蒸発缶と、
    　前記蒸発缶で生成された前記ＮＭＰ精製ガスを凝縮してＮＭＰ精製液を生成するコンデンサと、を有し、
    　前記容器は、前記受槽と前記膜脱気装置と前記原液槽と前記中継槽と前記コンデンサの少なくともいずれかである、請求項１に記載の精製システム。     A receiving tank for the NMP aqueous solution to be treated;
    A membrane deaerator for removing dissolved oxygen contained in the NMP aqueous solution supplied from the receiving tank;
    A stock solution tank for receiving the NMP aqueous solution treated by the membrane deaerator and supplying the NMP aqueous solution to the pervaporation membrane device;
    A relay tank for receiving the NMP concentrate concentrated in the pervaporation membrane device;
    An evaporator that evaporates the NMP concentrate supplied from the relay tank to generate NMP purified gas;
    A condenser for condensing the NMP purified gas generated in the evaporator and generating an NMP purified liquid,
    2. The purification system according to claim 1, wherein the container is at least one of the receiving tank, the membrane deaerator, the stock solution tank, the relay tank, and the capacitor.
  13. 　ＮＭＰと水とを含むＮＭＰ水溶液の精製方法であって、
    　浸透気化膜装置で前記ＮＭＰ水溶液から水を除去してＮＭＰ濃縮液を生成することと、
    　前記浸透気化膜装置の上流または下流に設けられ、前記ＮＭＰ水溶液または前記ＮＭＰ濃縮液が貯留される容器の気相部を不活性ガスで充填することと、を有するＮＭＰ水溶液の精製方法。
          A method for purifying an NMP aqueous solution containing NMP and water,
    Removing water from the NMP aqueous solution with a pervaporation membrane device to produce an NMP concentrate,
    A method for purifying an NMP aqueous solution, comprising filling a gas phase portion of a container provided upstream or downstream of the pervaporation membrane device and storing the NMP aqueous solution or the NMP concentrated solution with an inert gas.
PCT/JP2018/006954 2017-05-10 2018-02-26 Nmp aqueous solution purification system and purification method WO2018207431A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2019516899A JP6783384B2 (en) 2017-05-10 2018-02-26 NMP aqueous solution purification system and purification method

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2017-093935 2017-05-10
JP2017093935 2017-05-10

Publications (1)

Publication Number Publication Date
WO2018207431A1 true WO2018207431A1 (en) 2018-11-15

Family

ID=62861364

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2018/006954 WO2018207431A1 (en) 2017-05-10 2018-02-26 Nmp aqueous solution purification system and purification method

Country Status (3)

Country Link
JP (1) JP6783384B2 (en)
CN (2) CN207632732U (en)
WO (1) WO2018207431A1 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2020146635A (en) * 2019-03-14 2020-09-17 オルガノ株式会社 Dehydrator and dehydration method for liquid mixture including organic solvent and water
JP2020148152A (en) * 2019-03-14 2020-09-17 オルガノ株式会社 Removal method and removal device for condensate in gas flowing into vacuum pump
JP2020146639A (en) * 2019-03-14 2020-09-17 オルガノ株式会社 Dehydration apparatus and dehydration method of organic solvent
JP2020146637A (en) * 2019-03-14 2020-09-17 オルガノ株式会社 Refining system and refining method of mixed liquid containing organic solvent and water
JP2020146636A (en) * 2019-03-14 2020-09-17 オルガノ株式会社 Distillation refining apparatus of organic solvent and distillation refining method
JP2021053588A (en) * 2019-09-30 2021-04-08 オルガノ株式会社 Refining method and refining system of organic solvent
JP7462499B2 (en) 2020-07-16 2024-04-05 オルガノ株式会社 Organic solvent purification method and purification system

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN207632732U (en) * 2017-05-10 2018-07-20 奥加诺株式会社 The purification system of NMP aqueous solutions
CN110314547A (en) * 2019-07-22 2019-10-11 谛艾恩(北京)科技发展有限公司 Infiltration-vaporization mass transfer method and its device

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04298221A (en) * 1991-03-25 1992-10-22 Tsusho Sangyosho Kiso Sangyokyokucho Membrane separator
JP2003081885A (en) * 2001-09-13 2003-03-19 Mitsubishi Chemicals Corp Method for preventing organic compound from deteriorating
JP2013018747A (en) * 2011-07-12 2013-01-31 Japan Organo Co Ltd Nmp purification system in electrode production process
JP2015071139A (en) * 2013-10-03 2015-04-16 オルガノ株式会社 System and method for separation of liquid organic material and water
JP2016030233A (en) * 2014-07-29 2016-03-07 オルガノ株式会社 Organic solvent refining system and method
US20170043302A1 (en) * 2015-08-12 2017-02-16 North Carolina State University Pervaporative removal of water from ionic liquid mixtures using ionomeric membranes

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001354769A (en) * 2000-06-16 2001-12-25 Toopuren:Kk Method for recovering and purifying n-methyl-2- pyrrolidone
KR101125853B1 (en) * 2009-07-29 2012-03-28 에스케이종합화학 주식회사 Process for preparing of n-methyl pyrrolidone
JP5471221B2 (en) * 2009-09-14 2014-04-16 三菱化学エンジニアリング株式会社 NMP distillation equipment
CN102659824A (en) * 2012-05-04 2012-09-12 广东先导稀材股份有限公司 Trimethyl gallium purification system and purification method
KR101565033B1 (en) * 2014-03-28 2015-11-03 (주)신성이엔지 NMP recovery purification system
CN207632732U (en) * 2017-05-10 2018-07-20 奥加诺株式会社 The purification system of NMP aqueous solutions

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04298221A (en) * 1991-03-25 1992-10-22 Tsusho Sangyosho Kiso Sangyokyokucho Membrane separator
JP2003081885A (en) * 2001-09-13 2003-03-19 Mitsubishi Chemicals Corp Method for preventing organic compound from deteriorating
JP2013018747A (en) * 2011-07-12 2013-01-31 Japan Organo Co Ltd Nmp purification system in electrode production process
JP2015071139A (en) * 2013-10-03 2015-04-16 オルガノ株式会社 System and method for separation of liquid organic material and water
JP2016030233A (en) * 2014-07-29 2016-03-07 オルガノ株式会社 Organic solvent refining system and method
US20170043302A1 (en) * 2015-08-12 2017-02-16 North Carolina State University Pervaporative removal of water from ionic liquid mixtures using ionomeric membranes

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2020146635A (en) * 2019-03-14 2020-09-17 オルガノ株式会社 Dehydrator and dehydration method for liquid mixture including organic solvent and water
JP2020148152A (en) * 2019-03-14 2020-09-17 オルガノ株式会社 Removal method and removal device for condensate in gas flowing into vacuum pump
JP2020146639A (en) * 2019-03-14 2020-09-17 オルガノ株式会社 Dehydration apparatus and dehydration method of organic solvent
JP2020146637A (en) * 2019-03-14 2020-09-17 オルガノ株式会社 Refining system and refining method of mixed liquid containing organic solvent and water
JP2020146636A (en) * 2019-03-14 2020-09-17 オルガノ株式会社 Distillation refining apparatus of organic solvent and distillation refining method
JP7177733B2 (en) 2019-03-14 2022-11-24 オルガノ株式会社 Purification system and purification method for mixed liquid containing organic solvent and water
JP7213109B2 (en) 2019-03-14 2023-01-26 オルガノ株式会社 Method and apparatus for removing condensate from inflow gas of vacuum pump
JP7217648B2 (en) 2019-03-14 2023-02-03 オルガノ株式会社 Dehydrating apparatus and dehydrating method for mixed liquid containing organic solvent and water
JP7220597B2 (en) 2019-03-14 2023-02-10 オルガノ株式会社 Organic solvent distillation purification device and distillation purification method
JP2021053588A (en) * 2019-09-30 2021-04-08 オルガノ株式会社 Refining method and refining system of organic solvent
JP7328859B2 (en) 2019-09-30 2023-08-17 オルガノ株式会社 Organic solvent purification method and purification system
JP7462499B2 (en) 2020-07-16 2024-04-05 オルガノ株式会社 Organic solvent purification method and purification system

Also Published As

Publication number Publication date
CN207632732U (en) 2018-07-20
CN108863887A (en) 2018-11-23
JP6783384B2 (en) 2020-11-11
JPWO2018207431A1 (en) 2020-01-16

Similar Documents

Publication Publication Date Title
WO2018207431A1 (en) Nmp aqueous solution purification system and purification method
JP6440156B2 (en) Organic solvent purification system and method
JP4996925B2 (en) Apparatus and method for osmotic membrane distillation
JP6636111B2 (en) Organic solvent purification system and method
KR101020316B1 (en) Forward osmotic desalination device using membrane distillation method
JP6415159B2 (en) Organic solvent purification system and method
JP6088265B2 (en) NMP purification system and NMP purification method
JP2020146639A (en) Dehydration apparatus and dehydration method of organic solvent
JP2017113675A (en) Forward osmosis water making system and operation method of forward osmosis water making system
JP7217648B2 (en) Dehydrating apparatus and dehydrating method for mixed liquid containing organic solvent and water
JP7106474B2 (en) N-methyl-2-pyrrolidone purification method, purification device, recovery purification method, and recovery purification system
KR101298724B1 (en) Forward osmotic desalination device using membrane distillation method in which a part of draw solution is directly fed to a forward osmotic type separator
JP2023086951A (en) N-methyl-2-pyrolidone purification method and purification system
CN211561936U (en) Organic solvent dehydration device and refining system
JP7177733B2 (en) Purification system and purification method for mixed liquid containing organic solvent and water
JP7220597B2 (en) Organic solvent distillation purification device and distillation purification method
JP7246212B2 (en) How to replace consumables
JP7213109B2 (en) Method and apparatus for removing condensate from inflow gas of vacuum pump
JP7190377B2 (en) Analysis apparatus, analysis method, and purification system in purification system for mixed liquid containing organic solvent and water
WO2019193951A1 (en) Organic solvent purification system and method
JP2020193177A (en) N-methyl-2-pyrolidone purification method and purification system
JP2022129708A (en) Forward osmosis water treatment device and method

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18799104

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2019516899

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18799104

Country of ref document: EP

Kind code of ref document: A1